VENTILATION
of
DWELLING HOUSES
AND THE
UTILIZATION OF WASTE HEAT FROM OPEN FIRE-PLACES,
INCLUDING
0n
BY
FREDERICK EDWARDS, JUNIOR,
Author of "Our Domestic Fire-places" "A Treatise on Smoky Chimneys" &c.
SECOND EDITION, REVISED,
LONDON: LONGMANS, GREEN & CO
1881.
l«
DRYDEN PRESS : J. DAVY AND SONS, LONG ACRE, LONDON.
CONTENTS.
CHAPTER I.
PAGE.
A SHORT ACCOUNT OF THOSE WHO HAVE INTRODUCED ARRANGE- MENTS FOR VENTILATING PUBLIC BUILDINGS, AND OF THE SYSTEMS ADOPTED. Introductory Remarks . . . . . i
Agricola. ' De Re Metallica ' . . . .2
Sir Christopher Wren . . . . . .2
Dr. Desaguliers . . . . . . .3
M. Gauger. ' La Mecanique du feu ' . . .3
Dr. Desaguliers and Sir Jacob Ackworth . . . .7
Dr. Hales's Ventilating Bellows . . . . -9
Mr. Samuel Sutton . . . . . . 13
Sir John Pringle, John Howard, and Captain Cook . .18
Sir Humphrey Davy . . . . . .20
The Marquis de Chabannes . . . . .21
His Ventilating Lamp, Chimney Ventilator, and System of Venti- lating by Gas .... .26
Mr. Thomas Tredgold . . . . .29
Dr. David Boswell Reid . . . . .29
Mr. Goldsworthy Gurney . . . . . .42
Dr. Percy ... .45
Dr. Neil Arnott .... .46
His Modifications of the Marquis de Chabannes' Chimney Ventilator
and Dr. Hales's Ventilating Bellows . . -47
CHAPTER II.
ON SOME SIMPLE APPLIANCES FOR VENTILATING DWELLING-HOUSES. Introductory Remarks . . . . . -5°
I. Contrivances which provide for the entrance of fresh air. No. i. Perforated Zinc . . . . -62
No. 2. Wire Gauze . . - • -63
CONTENTS.
PAGE.
No. 3. Air-bricks in iron or brick . • • 3
No. 4. Sliding- valves • 3
No. 5. Perforated Glass. Lockhead's Patent Ventilator . 63
No. 6. Baillie's or Moore's Louvre Ventilator - 63
No. 7. Cooper's Ventilator . • • • • 64
8. Sheringham's Ventilator . . • • • 64
No. 9. Mr. William Cooke's and Mr. Stephen Flexen's Systems . 64
No. 10. Mr. Obed. Blake's System . • • • 64
No. n. Mr. Boyle's Ventilator . . • • -65
No. 12. Mr. Charles Gammon's Ventilator . . -65
No. 13. Louvre Boards over a doorway . . . 66
Tobin's System of Vertical Tubes . - 66
II. Contrivances which provide for the exit of air.
No. i. The Chabannes' Ventilating Lamp for Bedrooms . .67
No. 2. The Chabannes' Chimney Ventilator . . 67
No. 3. Dr. Arnott's Self-regulating Chimney Ventilator . . 67
No. 4. Mr. Joseph Toynbee's Chimney Ventilator . . 68
No. 5. Mr. Thomas Boyle's Chimney Ventilator . . 68
No. 6. Dr. Chowne's Inverted Syphon System . . .68 No. 7. Systems of Ventilating Gas Burners and Ventilating Rooms
from the Ceiling . . . . . .69
The Marquis de Chabannes' Arrangement ; the Sun Burner • Pro- fessor Faraday and Mr. Rutter . -7° Modification of Mr. Tredgold's proposal of Ventilating from the
Ceiling . . . . . . . 71
Grates fitted with Warm-air Chambers for supply of Fresh Warm Air 7 2
Review of different Systems . . . . -73
Objections made to Chimney Ventilators . . . -75 Dr. Arnott's opinions on the Open Fire-place and the Chimney Ven- tilator . . . . . . . • . 77
Ventilator over doorway . . . . . . 78
Ventilation of basements . . . . . . 78
Ventilation of Kitchens . . . . . -79
Ventilation of Ground Floor, &c. . . . .80
Ventilation of Dining Rooms . . . . .81
Ventilation of Library . . . . . . 8 £
CONTENTS. V
PAGE.
Ventilation of Drawing Rooms . . . . .81
Ventilation of Bed Rooms . . . . .82
Ventilation of Attics . . . . . -83
Ventilation of Cupboards and Closets . . . .84
Ventilation of Water-closets . . . . .84
Ventilation of a Room without a Fire-place . . 85
Ventilation Appliances adapted to New Constructions . .86
Mr. Boyd's Ventilating Flues . . . . .86
Messrs. H. Doulton and Co.'s Earthen Ventilating and Smoke Flue 87
Combined System for removal of Smoke and for Ventilation, sug- gested by Board of Health Commissioners on Warming and
Ventilation . . . . . . -87
Suggested Modification of the System . . . -91
Ventilating Shafts in Partitions or Partition Walls . . -93
Mr. George Jennings' System for admitting Fresh Warm Air . 93
Perforated Cornice . . . . . -94
Suggestions for Ventilating above every Window . . -95
Systems of Ventilating School-rooms, Work-rooms, &c. . . 96
Mr. McKinnelPs Ventilator . . . . .96
Mr. Muir's Ventilator . . . . . -97
Mr. Watson's Ventilator . . . . . -97
Mr. Thomas Harris's Ventilator . . . . -97
Mr. Chadwick's Archimedian Screw Ventilator . . .98
CHAPTER III.
LONDON SMOKE AND FOG . . . . . .100
The use of Gas for Warming, &c. . . . . . 101
Anthracite Coal or Coke . . . . . .102
Dr. Siemens' Grate . . . . . .102
Tax on open Fire-places . . . . . .103
Heating a number of Houses from a single source . .103
Heating Houses entirely by Hot Water, Steam or Hot Air . 1 04
Carrying off Smoke into sewers, &c. . . . .104
How to use Bituminous Fuel in open Fire-places, with little or no
Smoke . . . . . . . in
Use of Fuel in Kitchens . . . . . .113
CONTENTS.
CHAPTER IV.
PAGE.
FIRE-PLACES, VENTILATION AND SMOKY CHIMNEYS . 116
:.iin Gallon's Ventilating Grate . . . .118
: 'arson's Grate . . .119
The Slow Combustion or Norwich Stoves . . . .122
•tsford Grate . . . . .127
Conclusions . . . . • • .127
CHAPTER V.
CONSIDERATIONS ON THE UTILIZATION OF WASTE HEAT FROM OPEN FIREPLACES, AND ON A COMPREHENSIVE SCHEME FOR THE SUPPLY OF HEAT TO DWELLINGS . . .130
Plates and Descriptions, Figures i to 106 . . 146 to 178
TO THE PRESS.
ANEW edition of this book has been often asked for and promised. At last it appears. That it has not appeared before is due to a very simple cause, the explanation of which may not be devoid of utility. When the previous edition appeared, the publisher followed the usual course and sent about sixty copies to the press for review. A few notices appeared, some- times very short, and after a long period, showing that some writers did not care to spend much time or thought on the subject. As he had comparatively little assistance from the proprietors and editors of newspapers the author had to depend for a sale of his book on the issue of adver- tisements, which cost him a very considerable sum. There is, however, a necessary limit to such a state of things. It is not very satisfactory to labour in the public interest, and to pay heavily for it in time, money and disappointment. The author, therefore, delayed the issue of a new edition till the time appeared opportune. He hopes that is now the case, and will simply add that as long as the proprietors of newspapers do not take a higher sense of public duty, as long as there is not a systematic examination of books sent for review, so long will many writers on public subjects have grounds for grievous complaint. Some papers have however given him generous support, and to these he returns heartfelt thanks.
On the present occasion, instead of sending out a large number of copies for review, some of which may never
Vlii. PREFACE.
be reviewed, the author decides to issue the book chiefly to those editors who have a desire to review it. Such papers as the Times and the Saturday Review must have had a host of his books and have received a large sum for advertisements, but have never given him the slightest support.
He will now say a few words about the express purpose of this book. This is to offer sound practical advice on the ventilation of dwelling houses, so far as it relates to the admission of fresh air, the withdrawal of impure air, the economical warming of dwellings, and the prevention of smoke. An exhaustive consideration of the subject of ventilation would entail an enquiry into every cause of impurity, and open up the entire subject of sewage and drainage. This the author does not attempt. The subject of Healthy Dwellings has been recently discussed by Captain Douglas Galton and Mr. Eassie. But so wide is the range of subjects that Capt. Galton, in a volume of much greater extent than the present, is compelled to refer his readers to a number of authorities on matters of practical detail.
Since the publication of the previous edition, the Tobin system of ventilation has been introduced, has been found to possess no novelty and not to solve the question of ventilation. The Moule system of earth closets has been introduced and so largely advertized that we must conclude it is extensively used in country districts and abroad, though it appears to be utterly ignored where drainage and sewage exist ; the Moule system of burning chalk and coal has been laid before the world through the influence of the Times, but appears to be an utter failure
PREFACE. IX.
as nothing seems now to be heard of it. Lastly the Country Parson's Grate, or more properly speaking the late Mr. Leslie's grate, has been brought forward but appears in the estimation of the manufacturers to be a practical failure, as the contrivance they sell as a Country Parson's Grate is something in which the principle of that grate is widely departed from. All these schemes have been brought into notice through the influence of the Times, which has never given the author of this book any support whatever, which has rejected his letters, while it has readily accepted those from people who have done little or nothing to enlighten the public on such matters. Whether such a course contributes to the pecuniary success of the paper, he will not say, but he has a very strong opinion that it is not the way in which a public duty should be performed.
However the writer has some reason to suppose that his labours have not been without public benefit, even though they may have been of little benefit to himself. In most modern grates, the principle of slow combustion, which he has been recommending for twenty-five years past, has been introduced in some form or other. I none case, that of the Coalbrookdale Company, the principle of controlled combustion has been recently adopted on the method introduced by the author seventeen years ago but though he has urgently represented to that Company that, as a matter of courtesy and honour, they should describe their grates as constructed on the principle in- troduced in 1863 by himself, he has utterly failed to persuade the managers to comply with a just and reason- able demand. The principle of heating a large number
x. PREFACE.
of houses from a single powerful furnace, which the author discussed in the previous edition of this book, has not been introduced in this country, but has been introduced in America, where his volumes have circulated.
The system of utilizing waste heat has not been used to his knowledge, but he hopes that the modified system of utilizing the waste heat which passes from the fire, up the chimney simply to the height of the ceiling, will have a better chance of becoming adopted.
The writer will now only allude to the amendments of the Building Acts, which a rather lengthened experience has shewn him to be absolutely required. He has shewn that by some of our chimneys we discharge as much as from twenty to sixty thousand cubic feet of air per hour. This air does not come entirely from our houses or we should die from inanition. It comes from our doors and windows, occasioning draughts of cold air. It comes up from the basement of a house, bringing with it smells of cookingand other impurities. 1 1 descends unused chimneys, bringing with it a smell of soot, and causing them to smoke when a fire is lighted. It comes down the short chimneys of our attics and small back rooms, built outside the main structure of a house, rendering them cold, uncomfortable, and the chimneys the most incorrigibly smoky ones, with which the builder has to deal, and it comes from even worse sources. It comes up the numerous escape pipes which communicate with our drains and sewers, bringing with it abominable contamination. If the air does not come in, in sufficient quantity to replace what passes away, what do we get ? We get a close atmosphere, sluggish currents in our chimneys, and an occasional return of
PREFACE. XI.
offensive products of combustion. All these evils are to be effectually dealt with, in additions to the Building Acts by two necessary provisions.
The first is that the discharge of air by our chimneys should in all cases be effectually checked by means of the properly constructed register door recommended by Dr. Reid, Dr. Neil Arnott and by the writer, which any person may open more or less without injuring or soiling his hands. The second addition is that a supply of fresh air from an external source should be compulsorily admitted in connection with every fire-place to replace the minimum quantity which passes away by the chimneys, so that we may not depend on a mere chance supply by doors and windows. We may admit the air warm or cold as we please. It is far better to admit the air warm than cold, either at the upper part of the grate or near the ceiling, as we get air at 100 or 1 10 degrees instead of from 30 to 50, and we greatly economise our coal. By these two impor- tant improvements we gain the following advantages —
1. Economy in fuel.
2. An absence of draughts.
3. An absence of closeness.
4. An absence of smoky chimneys.
5. No rush of air from the basement with smell of
cooking, &c.
6. Attic floors and small rooms with short chimneys
easily warmed and perfectly habitable.
7. The chance of the entrance of foul air by escape
pipes reduced to a minimum.
The value of the principle contained in these propo- sitions is so evident and may be so easily ascertained and
Xll. PREFACE.
corroborated by experienced men that the value attaching to them should undoubtedly receive as early as possible the sanction of the Legislature. The matter is not one that ought to be left to individual caprice, because we have the inexperience of architects, the inexperience of the public, and the inexperience or selfishness of builders to take into consideration. But for the public apathy of the principle would have become established very many years ago. It was introduced by M. Gauger in France in 1715, by Dr. Desaguliers in this country at the same period, by the Marquis de Chabannes early in the present century, and in more modern days by Mr. Cundy the elder, an architect, by Mr. William Pierce, of Jermyn Street, and has been used by Mr. Robson, for the London School Board, by Mr. Alfred Waterhouse, by the present writer, and by many others, and is undoubtedly the principle which we must adopt if we wish to have our houses economically warmed and ventilated with a freedom from the entrance of smoke.
Copies of the author's publications will be sent to those editors who desire to receive them, on application being made either to Messrs. Longmans', or to himself.
49, GREAT MARLBOROUGH STREET, December 24^, 1880.
ON VENTILATION AND HEAT.
CHAPTER I.
A SHORT ACCOUNT OF THOSE WHO HAVE INTRODUCED ARRANGEMENTS FOR VENTILATING PUBLIC BUILD- INGS, &c., AND OF THE SYSTEMS ADOPTED.
A DESCRIPTION of some simple appliances for ventilation, A\. and certain suggestions for the utilization of waste heat in dwelling-houses, may perhaps usefully be preceded by a short account of those who brought the subject of ven- tilation into prominent notice, and operated with success in its application chiefly to public buildings. Persons of general information are necessarily aware that it is only within about thirty years that the advisability of providing special facilities for changing the air of ordinary apartments has been extensively recognized, but it would be erroneous to infer that indifference to the subject at previous periods is to be attributed solely to a deficiency of knowledge with respect to the conditions necessary for maintaining a healthy existence. It is a fact worthy of remark, that the necessity for ventilation has increased with the demand for it. Fifty years ago or more, when the British fire-place was large and open, the volume of air which passed up the chimney, supplied abundantly from doors and windows,
2 ON VENTILATION AND HEAT.
insured a constant renewal in the apartment, though under uncomfortable conditions. Our predecessors, there- fore, were probably more often familiar with an excess of ventilation than with an absence of it, and they fre- quently encountered the evil to which they were accus- tomed by the use of large screens in winter, which answered the double purpose of protecting the body from cold currents of air, and of arresting and radiating much heat from the fire. It is not therefore surprising that a recognition of the practical necessity for ventilation appliances in dwellings has followed the introduction of contracted fire-places, better fitting doors and windows, and the use of coal gas for lighting, and that previous requirements were confined in a great measure to public buildings such as the Houses of Parliament, theatres, hos- pitals, &c., where the occasional or constant presence of many persons presented exceptional conditions.
Special arrangements for ventilation appear to have been first found necessary in mines ;* certain methods of moving or renewing air having been described by Agricola in his ' De Re Metallica,' several hundred years since, but it was at a much later date that any attempt was made to ventilate a public building. This was at the House of Commons by Sir Christopher Wren. The great archi- tect's arrangements were, as might be supposed, of a very simple nature. He had four large holes made in the ceiling of the chamber, one at each corner, and over each hole he placed a wooden trunk or channel which passed into the room above. As soon as the house became warm
* Bernan. ' History and Art of Warming and Ventilating Houses and Buildings,' 1845, Vol. II. p. 39. These volumes, it appears, were pub- lished under a nom deplume, and written by Mr. Robert Meikleham,C.E. The writer must express his acknowledgments to these volumes for the intimation they have afforded him of several sources of information with respect to the historical part of the subject, which would perhaps other- wise have escaped his notice.
ON VENTILATION AND HEAT. 3
by the presence of many persons, an interchange took place between the air in the house and that above the ceiling, the warm air of the house rising through the channels and cool air descending. The contrivance amounted practically to nothing more than increasing to a certain extent the area of the house, but it perhaps answered fairly the requirements of a time that was not as familiar as the present with attentive legislators and prolonged debates. A certain amount of inconvenience, however, was found to result from the descent of cold air at the holes in the ceiling on the heads of those situated beneath whenever the house became hot by the presence of many persons, which evil in 1723, Dr. Desaguliers, the distin- guished philosopher and mechanician, undertook to remove. Dr. Desaguliers appears to have been the first to make the subject of ventilating buildings a special study, and to have been led to it by a circumstance resulting from his French origin. Brought as a child to this country by pro- testant parents, after the revocation of the edict of Nantes, he became in mature years vicar of Edgware, chaplain to the Prince of Wales, and, what is more interesting to the student in physical science, the author of the elaborate and valuable * Course of Experimental Philosophy,' and of many contributions to the Transactions of the Royal Society. In the course of his investigations he became familiar with a book called * La Mecanique du feu/ by M. Gauger, in which very ingenious contrivances were described for improving the comfort and salubrity of apart- ments warmed by wood fires. Of this book Dr. Desagu- liers published a translation in 1715,* which, he says, led
* ' Fires Improved, or a New Method of Building Chimnies, so as to prevent their smoking, in which a small fire shall warm a room much better than a large one made in the common way. And the method of altering such chimnies as are already built, so that they shall perform the same effects. By Monsieur Gauger; made English from the French original by J. T. Desaguliers, LL.D. and F.R.S.' A second edition,
B 2
4 ON VENTILATION AND HEAT.
him " to make experiments on the purifying of air, con- veying it from one place to another, and changing it for the advantage of those that breathe it in close places to the detriment of their health." At the House of Com- mons he endeavoured to perfect Sir Christopher Wren's arrangements by means of fires kept burning over the ceiling of the chamber, which fires were designed to be supplied with air drawn from the body of the house through the air channels in the ceiling, and thus effectually with- draw the air which had come heated and contaminated, the essential principle of which was that fires should be supplied with air from an external source, and that warmed fresh air should be allowed to circulate in the apartment. This important principle will be alluded to in subsequent pages. The reverend doctor did not adopt the simple and effective device of supplying his fires and the chimney draught with air drawn only from the house. What he did was to carry tubes from Sir Christopher Wren's air holes and channels into the chimneys, and to make the tubes pass in contact with the fires, so that an ascending current might be facilitated by the rarefaction of the air within the tubes. Dr. Desaguliers records that when the fires were lighted early in the day, an ascend- ing current was maintained in the tubes and chimneys, and the old inconvenience was removed. He had, how- ever, to do with a certain personage who was not so interested as himself in the success of his scheme, and contrived, by a philosophy of her own, practically to defeat it. Mrs. Smith, the housekeeper, being disturbed in her possession of the rooms by the new-fangled contrivance, offered a passive resistance. She neglected to light the fires till the house became crowded and hot. There was
' with an appendix containing several further improvements made by the translator and others,' was published in 1736. The book is curious, from its being apparently the earliest publication relating to fire-places.
ON VENTILATION AND HEAT. 5
not time, therefore, for the ventilating tubes to be heated so as to become practically useful, and the results was that descending currents of cold air at the air holes renewed the old inconvenience, to the apparent discredit of the doctor. A little after this, Dr. Desaguliers succeeded in giving the House of Lords relief from cold draughts of air, and a committee being appointed in the House of Com- mons to consider the question of ventilation led to his being commissioned to make some contrivance for draw- ing the hot and foul air from the house by the agency of a person who would be more amenable to his control than the slyly-obstructive Mrs. Smith. The doctor accordingly removed his air tubes. He constructed instead a centri- fugal or blowing-wheel, and provided a man to turn it, who was called "the ventilator," and who was "to suck out the foul air, or throw in fresh, or to do both at once, according as the Speaker was pleased to command, whose orders ' the ventilator ' waited to receive every day of the Session." The blowing-wheel, shown in figs, i and 2, consisted of a cylinder with fans radiating from it, both enclosed in a drum seven feet in diameter, which was provided with two air channels, one to convey air pro- pelled by the fans, the other to allow air to enter the drum. The fans were set in motion by the " ventilator " turning a handle, who could propel air into the house or expel air from it, according as he placed the one channel or the other in communication with the house. The blowing-wheel was powerful, for Dr. Desaguliers testified that it could supply air through the aperture seven inches in diameter at the rate of a mile a minute. Some means, therefore, must have been necessary to prevent the old inconvenience of cold draughts, but what those means were is not stated, nor is it clear in what way the machine was made to inject and expel air simul- taneously. The old air holes and channels of Sir Chris-
6 ON VENTILATION AND HEAT.
topher Wren were in some way utilized in connection with the blowing-wheel, and so successful was the contrivance considered, that it remained in use, with some alteration, for a subsequent period of eighty years. In 1734, Dr. Desaguliers exhibited a model of it to the Royal Society, and, the attention of the lords of the Admiralty being called to the subject, they witnessed the operation of the wheel over the House of Commons, the result being an order for it to be tried on board a large vessel at Woolwich. At that time the only special means used for removing the air in the confined quarters of vessels was the wind-sail, which consisted simply of a common sail rolled into a tube, and so placed that it could take advantage of a pass- ing breeze, the fresh air sweeping through it from the upper end to the decks below. The wind-sail could never be more than a very rough contrivance in certain states of the weather. In calms, when ventilation was very neces- sary, it was useless ; and in stormy weather, when the hatches had to be closed and ventilation was most re- quired, it was unbearable, the result being that the amount of sickness, disease and death, always attendant on a long voyage, in consequence of men being in the frequent habit of breathing a very foul atmosphere, was truly appalling, and occasioned great complaints. Per- mission was given to Dr. Desaguliers to show how he could improve on the wind-sail by his mechanical means, but it is evident from the doctor's interesting narrative that he was not much more fortunate in dealing with a Board of Admiralty than inventors of more recent times. He succeeded in applying his blowing- wheel, and he put down his pipes for conveying fresh air and withdrawing the foul. He showed, to the satisfaction of all present at his experiments, that on charging a room with smoke, he could rapidly expel the smoke, and that his machine would therefore be efficacious in replacing foul air by fresh ; but
ON VENTILATION AND HEAT. 7
he had a warning of the reception his suggestion was likely to meet with, for an old man, who had been with the vessel to Jamaica, grumbled that though it was the best thing he had ever seen, he was sure it would never be suffered to be put in practice. The old man was right. Dr. Desaguliers soon found that he had to do with some who had no desire to be convinced. Sir Jacob Ackworth, surveyor to the navy, had attended their lordships to wit- ness the action of the blowing-wheel at the House of Commons, and he was requested to report on the experi- ments at Woolwich. He began by throwing difficulties in the way, and he avoided witnessing an experiment when the doctor was present. When he did attend, he chose a time when plenty of wind was blowing. He had his favourite wind-sails hoisted, and " Now," said he, to the doctor's representative, " I would have you work the engine and see whether that will throw out so much air as our wind-sails you see do." The man protested with astonishment, but in vain. He pointed out that the blowing wheel was to be used when the wind-sails were useless. But Sir Jacob knew with whom he had to deal, and he stuck to his prejudices. He would not stay any longer. He told Dr. Desaguliers afterwards that " he was sorry it succeeded no better, but he thought it might be a very pretty thing in a house ; " so that the worthy doctor exclaimed in indignation : "Now let every impartial person judge whether I have not reason to complain, for not one of the lords of the Admiralty, who talked of having many of these machines for the preservation of the health of the persons then going to Jamaica, so much as saw the ex- periment made. Nay, Sir Jacob himself, who condemned the thing, did not once see it, but made his report from another reporter whom he left behind to give an account. Thus ended my scheme, which I hoped would have been of great benefit to the public." The worldly prosperity of
8 ON VENTILATION AND HEAT.
Dr. Desaguliers appears not to have been assisted by his devotion to science, for he is stated to have died in great distress. The following lines to his memory have been quoted : *
" How poor neglected Desaguliers fell ; How he who taught two gracious kings to view All Boyle ennobled and all Bacon knew, Died in a cell without a friend to save, Without a guinea and without a grave."
Contemporaneous with Dr. Desaguliers was another reverend and frequent contributor to the ' Philosophical Transactions of the Royal Society,' and who was equally conspicuous in advocating the use of ventilators for close places. The Reverend Stephen Hales, D.D. and F.R.S., perpetual curate of Teddington and rector of Faringdon, took much interest in matters relating to the moral and physical well-being of his countrymen. " Could I but see," said the doctor, " the immoderate use of spirituous liquors less general, and the benefits of ventilators more generally known and experienced, I might then hope to see mankind better and happier." In 1758, Dr. Hales published a treatise on ventilators,f in which he dwelt
* Ency. Britt, Art. Desaguliers. The lines quoted from the poet Cawthorn. The facts described are taken from the ' Fires Improved,' 1736, and from the ' Course of Experimental Philosophy,' Vol. II., pp. 556-568. Second edition. 1745.
t ' A Treatise on Ventilators, wherein an account is given of the happy effects of many trials that have been made of them ; which has occasioned their being received with general approbation and applause, on account of their utility in many ways to the great benefit of mankind, viz. : in refreshing the noxious air of ships, hospitals and mines, to the better preservation of the health and lives of multitudes ; in preserving the timbers of ships much the longer from decaying ; in easily sweetening cask water, and curing the ill taste of milk from some food of cows ; in new methods of distilling plenty of good water at sea ; in refreshing the air, and keeping up and regulating the warmth of melon and cucum- ber-frames and hot green-houses. By Stephen Hales, D.D., Clerk of the Closet to her Royal Highness the Princess of Wales, F.R.S. and Member of the Royal Academies of Sciences at Paris and Bolognia. London, 1758.'
ON VENTILATION AND HEAT. 9
very fully on their utility, and gave complete details of the manner of making and working them, with diagrams of those he had hitherto applied. Dr. Hales, like Dr. Desa- guliers, proposed to ventilate a chamber by propelling fresh air into it, or by reversing the process and expelling air, but he was led to the adoption of different mechanical means by observing the action of bellows used for organ performances or at the smith's forge. A simple illustra- tion of his contrivance is given in fig. 3, which repre- sents a large oblong box closed on all sides, with the exception of certain openings protected by valves, two of which opened so as to allow air to enter the box, and two of which opened as to allow air to pass out. Within the box was a division board called the midriff, suspended at one end by leather hinges, and capable of being moved up and down like a flap by means of a handle which passed through the top of the box. A glance at the figure and accompanying explanation will suffice to show that with every movement of the division board or midriff, air both entered the box and was expelled from it, the valves provided at the apertures preventing anyretrogade motion. When the midriff was raised, air entered the box at a lower valve, and air was expelled at an upper one. When the midriff was depressed, air entered the box at an upper valve, and air was expelled at a lower one. To bring the contrivance into practical use, it was necessary that it should be fixed in a position as nearly contiguous as convenient to the place required to be ventilated. The valves opening outwards were then placed in com- munication with the chamber by means of an air channel of suitable dimensions, and the other valves were left exposed to the external air. With every movement of the handle a considerable quantity of fresh air was thus forced into the room, and if it was preferred to reverse the process and expel air from the room into the external
TO ON VENTILATION AND HEAT.
atmosphere, the air channel was made to communicate with the valves opening inwards, and those opening outwards governed the means of exit for the foul air. The valves consisted of wooden flaps suspended by leathern hinges, and readily opened or closed by the pressure of the air. Dr. Hales considered his contrivance to be most simple, and in principle analogous to the means used by nature for propelling air into the lungs of men, viz. by the easy rising and falling of the midriff. He suggested the title of " the lungs of a ship " when recommending his bellows for sailing purposes, and ingeniously argued :
" It ought in reason to convince us of the great importance that plenty of fresh air is to our welfare, when we consider that the great Author of nature has allotted near one half of the trunk of our body for the office of respiration or breathing only ; can any one, therefore, be so unreasonable as to grudge the little space these will take up in a ship, or the small labour they will require to furnish great plenty of fresh air ? Were an animal to be formed of the size of a large ship, we are well assured, by what we see in other animals, that there would be ample pro- vision made to furnish that animal with a constant supply of fresh air by means of large lungs, which are formed to inspire and breathe out air in the same manner as these ventilators do. Can it, therefore, be an unreasonable or an improper proposal to attempt to furnish ships, gaols, hospitals, &c., in the same manner with the wholesome breath of life, in exchange for the noxious air of confined places, which is rendered unwholesome by the great quantity of rancid vapours which are incessantly exhaling from human bodies, and are the occasion of much sickness and of the death of multitudes."
The learned doctor was familiar with a sad array of facts to give strength to his persistent endeavours. The " Ship-fever," the " Hospital-fever" and the " Gaol-fever," all similar in nature, because proceeding from common causes, recall even worse sanitary conditions than those with which we are now familiar ; but, in contriving his
ON VENTILATION AND HEAT. I I
remedy, it was more easy for Dr. Hales to draw an in- genious analogy from the subtle processes of nature, than to imitate those processes with success. He might propel fresh air into a place, and he might reverse the process with some little trouble and expel foul air. He might also, by a double set of bellows and air channels, as shown in fig. 4, carry on the two processes together. Such a complicated arrangement, however, as the last was un- necessary. Fresh air propelled into a room would force air to leave it if proper openings were provided, and air expelled from a room would, of course, allow an equiva- lent supply of fresh air to enter. Practically the venti- lating bellows were used sometimes for one purpose and sometimes for another. They were often very large, mea- suring as much as ten feet long, and were sometimes fixed in the upper part of a building, with a main channel and with branches leading to different parts. To each branch a shutter was provided, so that certain chambers might be ventilated at one time and certain others at another, the pump not being sufficiently large to do the whole simul- taneously. Dr. Hales first applied the machine to the county hospital and county goal at Winchester ; then to the Savoy prison, where a great decrease in the annual number of deaths was the consequence ; and subsequently to the goal at Newgate, and many other public buildings both in England and abroad.
A constant objection made to the ventilating bellows was the necessity for frequent manual labor to work them, which obliged the doctor to plead incessantly the cause of activity and health against stagnation and disease. He sought to stimulate the men who worked the bellows by the sight of a little twirling windmill, or the sound of a tinkling bell, occasioned by the rapid passage of the air, that they might thereby be amused, and have some evi- dence of their labor not being in vain. At Newgate,
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Dr. Hales constructed a windmill on the roof, which was for use instead of amusement, as it frequently sufficed to keep his bellows in motion without manual assistance. In certain vessels on long voyages, there was no objection made on the point of labor ; a letter from Captain Ellis, F.R.S., published in the Royal Society's ' Transactions,'* stating that "the bellows were far from inconvenient, and afforded good exercise for the slaves, and a means of pre- serving the cargo and lives." The treatise on ventilators was translated into French, and it has been stated that in France the advantages were so fully established, that the ventilators were immediately adopted by the French Go- vernment, and applied with success in a far greater number of cases than the inventor had ever contemplated. f
Between Dr. Hales and Dr. Desaguliers there was some little rivalry. Dr. Hales, in his early announcements, made no mention of his contemporary's contrivance, though, as Dr. Desaguliers reminded him, he had a little wheel by him at his house at Teddington. Dr. Desaguliers praised the ventilating bellows of his reverend friend, but slyly hinted at a similar contrivance having been in use in Sweden, and made known to Dr. Hales by a visitor to the Royal Society. Dr. Hales retorted, in his complete account of his ventilators published in 1758, by alluding to the blowing-wheel over the House of Com- mons, only to express a preference for his own arrange- ment, and slyly hinted that a similar device to that of Dr. Desaguliers had been described by Agricola. Dr. Hales even then avoided mentioning his contemporary's name, but he became punished for his want of due consideration
* ' Philosophical Transactions.' Vol. XLVII. 1750-51.
f In the celebrated 'Encyclopedic' of 1765, Dr. Hales is thus spoken of: " Le celebre M. Hales, un des grands physiciens de ce siecle et Pun des mieux intentionnes pour le bien public, a invent^ un ventilateur d'un usage presque universe!. M. Demours, medecin de Paris en a traduit en Francois la description. Paris in-i 2, 1744." Article, Ventilation.
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or candor by another rival for public distinction, who fought his way with no little pugnacity.
Mr. Samuel Sutton, brewer, being informed in the year 1739 that " the sailors on board the fleet at Spithead were so dangerously ill for want of fresh air that they were put ashore to recover their health, and the ships to which they belonged stunk to such a degree that they infected one another," thought himself obliged, as he states, " in com- passion to his fellow creatures, to do all that was possible for their relief in such unhappy circumstances." This brought him in contact with a Board of Admiralty, and so curious and entertaining is the account of his experience of naval authorities that the commissioners of patents were advised a few years since to reprint it.*
Mr. Sutton was led to adopt an entirely different system to that of the reverend doctors by observing that when fires were burning in rooms communicating with each other, air would often rush violently down one while it ascended the others. He reflected that if air descended a chimney to support combustion and maintain chimney draught in other chimneys, a common fire might be turned to account to withdraw the air of a place that required ventilation. In fact he proposed to utilize systematically, with respect to ships, the power which has for centuries ventilated our dwellings in cold seasons, viz., the simple use of an open fire. Mr. Sutton did not venture to ask that a fire should be kept burning m a ship for the sole purpose of ventilation, but he ingeniously made use of the ship's coppers. He shut off the ordinary supply of air to the fire and led tubes from the ship's hold and other
* ' An historical account of a new method for extracting the foul air out of ships and with the description and draught of the machines by which it is performed : in two letters to a friend. By Samuel Sutton, the inventor. The second edition. To which are annexed two rela- tions given thereof to the Royal Society by Dr. Mead and Dr. Watson. ' London, 1749.
14 ON VENTILATION AND HEAT.
places he desired to ventilate to the ash-pit below the fire. As soon as a fire was lighted, a constant supply of air through the air tubes supported combustion or escaped by the chimney, ensuring a constant entrance of fresh air through the port-holes into the chambers with which the tubes communicated, however calm might be the external atmosphere. Mr. Sutton obtained a patent for his arrange- ment, being naturally anxious to benefit himself as well as the navy, and, provided with a letter of introduction, he paid a visit to Sir Jacob Ackworth, the obstinate old knight who had proved so obstructive to Dr. Desaguliers. Sir Jacob made an appointment for Mr. Sutton to call on him on a future day at seven in the morning, when, being engaged, he allowed him to wait about till the evening. As he did not succeed in exhausting Mr. Sutton's patience he saw him, and after a little interrogation, he told him that no experiment should be made if he could hinder it. Mr. Sutton, however, was not the man to be easily thwarted. He succeeded in obtaining an order from the Admiralty for his contrivance to be tested, and, after some obstacles, his pipes were fitted to a man of war at Wool- wich. Before the work was completed, however, a mes- senger came from the king's yard to remove the pipes ; and, as Mr. Sutton foresaw nothing but continued obstruc- tion from government officers, he determined to seek assistance in a different quarter. He obtained an inter- view with Dr. Mead, F.R.S. and physician to His Majesty, which led to another interview, when Mr. Folkes, the president of the Royal Society, was present. Both these gentlemen approved of the scheme, and interested them- selves in its behalf. Dr. Mead immediately went to the lords of the Admiralty and represented in a strong manner the advantages of Mr. Sutton's system, whereupon they were pleased to order that it should be tried on board any of His Majesty's ships in the river. Mr. Sutton chose a
ON VENTILATION AND HEAT. 15
hulk at Deptford, and superintended the erection of his pipes. At last, in September, 1741, a day was appointed for an official experiment. The lords of the Admiralty, the commissioners of the navy, Dr. Mead, Mr. Folkes the president, and several other members of the Royal Society were present, when Sir Jacob Ackworth addressing them said : " I am sorry that you are come to see the trial of such a foolish experiment that I tried myself yesterday and it would not shake a candle ; " to which Mr. Sutton replied, that, " It would be in good humor to-day, and the end of every one of the pipes would blow out a candle." Mr. Sutton states that he was as good as his word, not- withstanding some attempt to thwart him, and that all the lords and gentlemen expressed their approbation. The result appeared promising, for Mr. Sutton was requested to go to Portsmouth to apply his plan to a vessel intended to proceed to the coast of Guinea, and was provided with a recommendation that he should meet with no obstruc- tion or discouragement from anybody that might think themselves wiser.*
Mr. Sutton executed his commission. The vessel was
* The following sensible letter from Sir Charles Wager, Secretary to the Admiralty, conveyed these instructions : —
"Admiralty Office, 24 Nov., 1741.
" SIR, — I send this by Mr. Sutton, who has found out a way to draw bad air out of close places, particularly from wells of ships, which you know are sometimes so bad as to stifle men before they can be drawn up, as happened on board the ' Lynn ' while I was at Helvoet-Sluys, one man being killed by it and two narrowly escaped. This contrivance is approved by much wiser men than I am in such things, and therefore I desire you would let Mr. Sutton have all the encouragement and assist- ance you can give him. I take Mr. Alleyn, your builder, to be an inge- nious man ; if you recommend Mr. Sutton to his care, he will see that he meets with no obstruction or discouragement from anybody that may think themselves wiser. There is an order from this Board to the Navy, from whom you will have it, to have the ' Norwich/ who is to go to the coast of Guinea, to be fitted according to Mr. Sutton's scheme, which will be a very good experiment. I am, Sir,
" Your humble servant,
" CHARLES WAGER."
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despatched, and, as he had spent a large amount of time, and been at considerable expense with his project, and as he in all probability resembled the vast majority of men with respect to a readily exchangeable commodity, he was anxious to obtain remuneration. But, like other in- ventors, he had to find that governmental bodies have generally little sympathy except with their friends and dependents. Time after time he petitioned the Admiralty without even receiving an answer to his applications, until, after great delay, the Norwich returned. The captain gave an equivocal report on Mr. Sutton's ventila- ting pipes, and insinuated that there had been danger of their taking fire. In the end, their lordships drew up an order on Mr. Treasurer, in which they stated that it ap- peared from the captain's report the invention did not in all respects come up to the expectation, and that the use thereof was dangerous and liable to accidents by fire, yet as the said Mr. Sutton had employed a great deal of pains and time about the said invention for the benefit of the navy and had encouragement from their lordships so to do ; and their lordships being desirous to give encourage- ment to persons who might turn their thoughts to any inventions that might tend to the advantage of the navy, did thereby desire and direct a bill of ^100 to be made out to the said Samuel Sutton as a reward for the loss of time and expenses he had been at about the said invention.
This was all the satisfaction Mr. Sutton could get two years after his first successful experiment, a sum which, he bitterly said, scarcely paid his expenses. But he was not beaten even yet. Dr. Mead brought his suggestions before the Royal Society. New men succeeded at the Admiralty, and Mr. Sutton at last had the satisfaction of informing his influential friend that his invention had sur- mounted all obstacles :
" through the wisdom and zeal of the present right honorable
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the lords of the admiralty, and the right honorable and honorable the principal officers and commissioners of his majesty's navy, who, having taken the whole affair into their serious considera- tion, were so thoroughly satisfied of the great advantages that must accrue to the nation from the faithful execution of my scheme, that the said principal officers and commissioners of his majesty's navy have contracted with me for fixing my engine on board his majesty's ships, whether laid up or in commission ; for which act of general concern, as I well know the warmth of your heart for the good of our country, I doubt not but you will readily concur with me in making cordial acknowledgments to their lordships and those honorable gentlemen in the name of the public. " Yours, etc.,
" SAMUEL SUTTON."
Thus ends this rather characteristic account of official obstructiveness and indifference. How long Mr. Sutton remained satisfied with his honorable and right honorable friends does not appear from his narrative, but, according to Mr. Bernan*, naval authorities objected to the recom- pense he demanded, and " in a year or two no other method of ventilation wa£ known on board ship but the * old way/ by wind-sails." H e had also to contend with powerful rivals. Dr. Desaguliers foolishly condemned Mr. Sutton's system. Dr. Hales took no notice of it in his book on ventilators, which occasioned the following outburst :
" Dr. Hales' ventilators, which were designed to answer the same purpose as my pipes, had by some means or other got such an ascendant in the esteem and regard of some leading persons in the affairs of the navy, as, in spite of conviction itself, to admit of nothing to come in competition with them ; though even that darling scheme is now out of date and exploded. Far be it from me to insult and triumph over a conquered adversary, and it is needless as well as cruel to spend much time in confuting a scheme that experience has shewn to be absurd and ridiculous. However, I think it incumbent on me to observe how much I was
* ' History and Art of Warming and Ventilating, &c.' Vol. II., p. 60.
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surprised to find no mention made, by the candid author, of the description of ventilators of my invention ; whereas he himself saw an experiment made before the Royal Society with a model of it, and heard Dr. Mead's account of it read to that learned body, which account was published in the ' Philosophical Tran- sactions.' "
This was probably quite enough for Dr. Hales of the not-over-refined and indomitable Englishman, with whom the early stage in the introduction of ventilating arrange- ments closes. Dr. Hales's ventilators no doubt had their day and were forgotten, and it is certain that Mr. Sutton, in promulgating the principle unconsciously used for cen- turies, of ventilating by the common fire and chimney draught, recommended the special application of a system that was intrinsically superior to the mechanical contri- vances of his reverend contemporaries. The blowing- wheel of Dr. Desaguliers and the bellows of Dr. Hales were powerful, but they occupied a certain amount of space, and required the systematic application of manual labor ; but, by Mr. Sutton's method, a power was utilized that already existed, and which might be purposely deve- loped without occasioning much trouble.
From this period for many years there appears to have been no one actively engaged on the subject of ventila- tion, but there were careful observers who noted and recorded the baneful effects of foul air on the human constitution, and who were conspicuously useful in mani- festing the necessity for good sanitary arrangements. Sir John Pringle lamented, in 1776, that " by a humiliat- ing fatality so often accompanying the most useful dis- coveries, the credit of Dr. Hales's ventilating bellows was yet far from being firmly established in the navy ; but he himself rendered considerable service by the publication of his ' Diseases of the Army.' The excellent John Howard was indefatigable, and Captain Cook notably
ON VENTILATION AND HEAT. 19
demonstrated what could be done by those who, with good intelligence, took a hearty interest in the well-being of their subordinates. The great circumnavigator, with a company of a hundred and eighteen men, performed a voyage of three years and eighteen days, passing through all climates from fifty-two degrees north to seventy-one degrees south, with the loss of only one man by disease, whose lungs were affected before he went on board. So extraordinary a result followed from the wisest precau- tionary measures. Captain Cook avoided excessive fatigue for his men, by appointing three watches instead of two. He protected the men from excessive heat and cold. Regularly every morning in the week he passed his ship's company in review, and saw that every man was as clean as circumstances permitted. He ordered the hammocks and bedding to be brought on deck in fine weather, and had every bundle unlashed and exposed to the air. He would have the sweetest water he could get ; he provided fresh water for washing, and, when opportunity offered, his casks were carefully emptied of their contents and filled anew. His ship was of course duly scrubbed and washed. Fires were burnt purposely in stoves both to dry the timbers and renew the air. The well of the ship was dried and purified by an iron pot containing fire being let down into it, which of course occasioned a rapid change of atmosphere.* With such precautions and happy results, it is not surprising that Captain Cook did not consider the use of fresh air-bellows or blowing-wheels to be a practical necessity. Indeed, the early systems of ventilation became so much forgotten, that some twenty to thirty years later, when Count Rum-
* These facts are taken from l A Discourse upon some late Improve- ments of the Means of preserving the Health of Marines, delivered at the Anniversary Meeting of the Royal Society, Nov. 30, 1776, by Sir John Pringle, Bart., President.'
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ford published his essays, he made scarcely any allusion to ventilation, his chief concern being to promote the better warming of rooms, the economy of fuel, and the preven- tion of smoke. Count Rumford was, however, the author of one suggestion, which has been renewed by others. He proposed that the rooms of a house might be supplied with fresh air from a large shaft built in the party- wall, the object being merely to provide air from the roof of a house, which would probably be more free from dust and other impurities, than when allowed to pass through the doors and windows at a lower level. Open gratings fixed in the rooms would allow the air to enter from the air-shaft. A peculiarity of the system is that it would be generally inoperative except when a fire was burning, and that its success would have to be insured by excluding, in a great measure, the entrance of air to a house by other means. This important proposition will have to be alluded to again.
It was in the year 1811 that Sir Humphrey Davy, the next conspicuous contributor, undertook to improve the warming and ventilation of the House of Lords. The fresh air, previously warmed in cold weather, he admitted through innumerable apertures in the floor, and foul air he with- drew at the ceiling, by the same system as that first attempted at the House of Commons by Dr. Desaguliers. He had two apertures made in the ceiling, which were covered by open wire-work, and from the apertures he arranged metal tubes, which were led into the external atmosphere. These tubes were considered sufficient for ordinary purposes, but when extra ventilation was required, fires were burnt around a part of the tubes to accelerate the velocity of the air passing through them. The ascending current caused by the rarefaction of the air was, however, insufficient to. maintain the chamber in a state of purity, as " his attempts are stated to have been a signal failure
ON VENTILATION AND HEAT. 21
from a miscalculation of the diameter of the pipes neces- sary to carry off the vitiated air in so large a building, and became a source of considerable mortification to him- self, as well as of malignant pleasantry to the witlings of that period." * There may be some satisfaction in reflect- ing that the great philosopher failed where other able men, who have devoted a far greater amount of attention to the subject, have but partially succeeded.
Another and a more successful contributor to the theory and practice of ventilation was the Marquis de Chabannes, a member of the old aristocracy of France, who, with fortunes almost ruined in consequence of the convulsions in France and St. Domingo, made his home in this country at times when revolution or despotism placed in- superable obstacles to his prosecuting an active career in his own. Certain pamphlets f of the Marquis, written with considerable clearness and force, explain the circum- stances which led him to propound new theories and plans for the warming and ventilation of public buildings and dwellings. He states, that on landing in England for the first time, in 1787, he was struck with the multiplicity of the first conveniences of domestic comfort among rich and poor. He admired the cleanliness, neatness and seclusion of English homes, and, while admitting the superiority of the fundamental principle upon which houses were con-
* < Ency. Britt.; Eight edition. Art. ' Davy.' The following lines have been quoted : —
" For boring twenty thousand holes, The Lords gave nothing d their souls."
t ' On conducting air by Forced Ventilation and regulating the tem- perature in Dwellings, with a Description of the application of the prin- ciples, as established in Covent Garden Theatre and Lloyd's Subscription Rooms, and a short account of different patent apparatus for warming and cooling air and liquids, the whole illustrated with copper-plate engravings, by the Marquis de Chabannes,' 1818. Also 'Appendix to the Marquis de Chabannes' Publication on conducting air by forced ventilation and equalizing the temperature of dwellings ; published in 1818.' The date of the appendix is not given.
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structed in Great Britain — viz., seclusion — he thought it surprising that so little attention had been paid to the means of preventing damp, and the ill-effects of cold draughts of air. Had the Marquis lived in our days, his opinion might have been somewhat modified, and he would probably have been appalled at the abject condition of the dwellings of a great portion of the laboring classes amidst so much prosperity and wealth. His actual observations, however, occasioned him to direct his attention to the general question of improving the temperature and salubrity of dwelling-houses, in the course of his various travels " through almost every country in Europe : " and he states that —
" In the year 1809, I published in Paris a slight sketch on the subject, and it is my intention at some future period to illustrate by practice what in theory appears perfect. To seek to create in man new wants, would be, instead of rendering him a service, aggravating the evils of his existence ; but to point out a variety of enjoyments within his grasp, yet which escape his penetration because unthought of, will, I think, be deemed adding to his happiness. This is my hope and has been the occupation of my leisure hours for many years past.
" In 1793, I rented a house on Barnes Terrace, and, at a little expense, I rendered it as comfortable as any in England. I afterwards occupied a house in Welbeck Street, which, during three winters was completely warmed by the fire of the kitchen alone, and in the various houses I have since inhabited in France, I have followed and improved upon this plan.
" In January, 1814, writing the whole day in London before a large fire, burnt on one side and frozen on the other by the current of cold air rushing into the room by every aperture to supply the draught of the fire, I felt more sensibly than ever the great defects of the present construction of stoves. In this situation, I first conceived the plan of the calorifere, and had a model executed with the intention of having some stoves made and taking them with me to France for my own use, when an order from the king obliged me to depart early in February for Flanders.
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" Sorrow and affliction induced me to quit France soon after the re-installation of the king, and I returned to England in the month of September following, weeping over the destiny of the house of Bourbon and the future miseries of my too-unhappy country. I then had a calorifere stove made from it with the sole design of guarding myself from cold, but the importance of the invention appeared to me to be so great, from the equal and agreeable warmth I immediately experienced in every part of my apartment, that I resolved to take out a patent, and to make public my long meditated plan for regulating the tempera- ture and conducting and purifying the air in our dwellings."
A portion of the preceding paragraph is to be accounted for by the fact that the Marquis aimed to be a politician as well as a man of science, and was one whose advice was unacceptable to the power he wished to uphold. But loyal to his own liberal opinions and to the house of Bourbon, the winds were always contrary, and opportunities from which he found himself incessantly debarred, occa- sioned him to embrace others which afforded scope for his abilities in matters of a less pretentious nature than those relating to the political well-being of his countrymen. By introducing the (< calorifere stove," alluded to in the extract, he was probably the first to make an attempt to establish a more powerful and economical means of warm- ing the rooms and halls of houses than by the old open grate. The stove was very largely used some forty to fifty years since, and it may still be seen occasionally. It con- sisted of a metal case, sufficiently open in front to allow the fire to be seen. At the back and sides of the fire was a series of iron tubes, each tube about two inches in diameter, arranged vertically, through which a current of air coming from an external source passed, and, after becoming heated by contact with the hot inner surface, entered the room by apertures provided at the top of the stove. Such a con- trivance, by presenting a large amount of radiating surface to the room, by lessening the current of air up the
24 ON VENTILATION AND HEAT.
chimney, and providing for the entrance of a constant current of fresh warm air, effectually preserved the Marquis from being " scorched on one side, and frozen on the other," and must have effected a great change for the better in the many spacious places where it was intro- duced. This is essentially the same principle as that introduced by M. Gauge r, and in all the ventilating grates which have succeeded his. The other contrivance alluded to by the Marquis is the plan now well known of heating a large quantity of water, at a distance from the kitchen boiler, by means of circulating pipes, the water being made in its course to travel through coils of pipe for the purpose of warming a hall, and the air about the stairs and landings of a house, and also for the additional purpose of supplying water for a warm bath. It was, in fact, the Marquis de Chabannes who first actively intro- duced the system of heating buildings by hot water in this country.
The Marquis took out patents for his inventions, intend- ing, as he says, to abandon them to persons already en- gaged in trade, and to reserve to himself " a small acknow- ledgment" from those he licensed, but, he proceeded in the first instance to get the leading physicians, architects, &c., to express an opinion upon his schemes. He ad- dressed a circular to them, in which he invited them to survey his improved systems at his private residence, and it is curious that this circular appears to have contained the first attempt to call the attention of the scientific to the necessity of ventilating the ordinary apartments of our dwellings. The Marquis said :
" Nothing would tend so much to the salubrity of dwellings as the expulsion of miasmata, more or less putrid, which arise from our breathing and perspiring, especially in bedrooms. The ex- clusion of damp air, the avoiding too sudden a passage from a warm to a cold room, and the guarding against noxious currents
ON VENTILATION AND HEAT, 25
of air (all of which are causes of numberless diseases), are the objects I have endeavored to attain, and, I trust, I have com- pletely succeeded." " Air being the great agent of our existence, on its purity depends in a great degree our breath and all the comforts of life. Every one knows that wherever man breathes, the constant introduction of fresh air is indispensable, and that the breathing of tainted air produces languor, decay, and finally death. The experience of all ages leaves evidence of its influence on health and longevity. Under these circumstances I apprehend, gentlemen, you will be of opinion that an efficacious method of purifying it, and regulating its admission at pleasure into your dwellings, is a most desirable object."
In a chapter " on air and its properties relative to res- piration," the Marquis anticipated much with which the public has become familiar. He explained the nature of a pure atmosphere, the means by which it is rendered impure, the noxious and perhaps ultimately fatal effects resulting from impure air, the inconvenience and distress encountered in crowded theatres, ball rooms, small bed- rooms, &c., and the absolute necessity of precautions being taken by those who valued a healthy constitution. Of the special means used by the Marquis in the withdraw- ing of vitiated air there is first a " chimney ventilator," shown in section in fig. 8, which was fixed so as to allow air to pass from the room into the chimney just below the ceiling, in exactly the same manner as by the " Arnott ventilator," introduced nearly thirty years subsequently. It operated by allowing an escape of air from above the room into the chimney whenever there was an ascending current in the chimney. A chain was provided to close the valve when not required for use, or when likely to allow the entrance of smoke. A second contrivance was a ventilating lamp, partly enclosed in a case of metal, which was so arranged as to give light to an apartment, and, at the same time, assist to ventilate it, while the products of combustion from the lamp effectually passed
26 ON VENTILATION AND HEAT.
away. The arrangement is shown in fig. 6, and in section as fixed in fig. 7, with the lamp behind the mantle-shelf, and the frame-work of iron let into the wall. The arrows indicate passages provided for the escape of air, &c., to the chimney. A more important arrangement is that shown in fig. 5, which represents an arrangement of gas- burners attached near to the ceiling of a public room, with a large tube of metal to convey away the products of combustion, and an external tube to allow the escape of air for ventilation, the whole being discharged by a cowl at the roof. Various openings are indicated by the arrows which were intended to provide for the escape of air from different parts of the chamber.
The Marquis obtained numerous certificates from pro- fessional men and others, in favour of his various contri- vances, provided with which he invited the stove-makers of London to offer them to the public ; but he found too much ignorance, prejudice and want of enterprise in that quarter to expect any practical assistance, and he was re- duced to the necessity either of abandoning his inventions, or of carrying them out himself. The Marquis did not abandon his inventions ; for possessing too sound an un- derstanding to think that it would be derogatory in him to submit to the necessities of his position, and promote his various objects by every honorable means in his power, he commenced and established a house of business in the now wretched locality of Drury Lane, where he rapidly gained considerable support. If the Marquis was in ad- vance of his time, in attempting to introduce special means for ventilating ordinary apartments, he yet found ample scope for his talents in places where the most stolid could hardly fail to find reason to complain. The House of Com- mons was at this period by no means the worst ventilated chamber in the country, the ventilating wheel of Dr. De- saguliers, erected when requirements were smaller, having
ON VENTILATION AND HEAT. 27
remained to be of some practical benefit till this period. Advice and assistance were sought from the Marquis, who removed the blowing-wheel, and also Sir Christopher Wren's air tubes, and who both contrived and carried out a far more elaborate system of warming and ventilation than had previously been conceived of. For the purpose of warming, the Marquis applied a number of coils of iron pipe under the members' seats, which coils were heated in winter by steam passing through them from a steam-boiler placed in a convenient position beneath the chamber. Air was allowed to flow into the house at various positions after being warmed by the steam coils. For the purpose of removing vitiated air from the upper part of the chamber, the Marquis adopted the analogous system of placing a number of steam coils in various posi- tions over the ceiling and over the galleries, which were designed to create by rarefaction of the air surrounding them currents at various parts, and thus to occasion a general ascent of air from the body of the chamber through the air apertures in the ceilings, and past the steam coils into certain channels which terminated in one main chan- nel of exit at the roof of the building. The air was then discharged at a cowl four feet in diameter. The heated products from above the chandelier were allowed to pass away direct into the main ventilating channel, and contri- bute to the general efficiency. The Marquis's method, elaborate and ingenious as it was, was not entirely suc- cessful. He was probably unable to regulate sufficiently the temperature of pipes heated by steam to adapt such a system to the necessities of our varying climate, though steam is the medium now actually used for heating the air in the House of Commons, with the assistance of certain arrangements that render its use more practicable. For the escape of foul air, the power employed was greater than before, though still insufficient. The Marquis was a
28 ON VENTILATION AND HEAT.
great innovator on previous practice, but it was reserved to a later period for it to be established what a truly enormous quantity of fresh air is required to pass on certain occasions through the House of Commons, to main- tain it in a state of purity.*
The Marquis carried out similar plans at Covent Garden Theatre, which he rendered the only tolerably well venti- lated theatre in London. Besides exhibiting his plans for a time in operation at his own house, he ventilated at his own expense, for public exhibition, a metropolitan bazaar, which was destroyed by fire, and numerous other public buildings mentioned in his pamphlet. But though he was so far successful in gaining public attention to his improved methods, it is doubtful whether he ever got that measure of worldly success which often follows from the reso- lute and systematic exercise of the selfish instincts. It is the frequent case of the ingenious and inventive that their generosity is more noticeable than a less amiable quality, but, whatever may have been the case with the Marquis he retired to France, after a few years career as a trades- man, and spent his latter days near to Rouen, where he died.f
At about the time the Marquis was most active, Mr. Thomas Tredgold, a civil engineer, took up the question of warming and ventilation, and published a practical
' The author hopes no one will be so inconsiderate as to consider him to be sarcastic.
f The following are the titles of the Marquis's patents.
A.D. 1799, No. 2364. Separating large from small coal, and consoli- dating the latter.
A.D. 1815, No. 3875. Apparatus for consuming smoke, and warming apparatus.
A.D. 1815, No. 3963. Pneumatic apparatus for producing currents of air in flues : apparatus for evaporating and cooling fluids : ventilation of chimneys.
A.D. 1817, No. 4191. Constructing metal tubes.
A.D. 1817, No. 4192. Apparatus for ventilating apartments, ships, &c. and for promoting draught in flues.
ON VENTILATION AND HEAT. 29
work of some value,* which reached a third edition in 1836. Mr. Tredgold was a strong advocate of the use of steam for warming, but he appears to have been remark- ably ignorant of what had been done by others, as he made no allusion to the Marquis, or to the system adopted in the Houses of Parliament. Mr. Tredgold was a tolerably careful observer of facts rather than an originator, and his observations on the movements of air were chiefly of assistance in facilitating the labors of others.
Following immediately on Mr. Tredgold, is the well- known name of one who has probably contributed more effectually than any other to enunciate scientific principles of ventilation, and to reduce those principles to practice. In the year 1834, Dr. David Boswell Reid was lecturing at Edinburgh on sanitary subjects and chemistry, and had class rooms so admirably arranged to illustrate principles of warming, lighting and ventilation, that when the British Association for the Advancement of Science held a meeting at Edinburgh in that year, Dr. Reid became a centre of much public attention. In the month following, a great portion of the Houses of Parliament was destroyed by fire. What up to that time had been the House of Peers was thenceforth used as the temporary House of Commons, and the Peers removed to another chamber. The ventilating arrangements of the new Commons' cham- ber, imperfect before, were found utterly insufficient for the larger assembly. A committee on the subject was appointed in the year following, when Dr. Reid was ex- amined and consulted. This led to a recommendation that he should be employed, both with a view to his giving present relief, and that his arrangements might afford guidance with respect to the requirements of the new legislative building that was to be erected. Dr. Reid dealt
* ' The Principles of Warming and Ventilating Public Buildings, &c., by Thomas Tredgold, civil engineer, &c.' Third edition, 1836.
3O ON VENTILATION AND HEAT.
with his subject in such a manner as to throw completely into the shade what had been attempted before. Pre- vious to commencing, he wisely made experiments at Edinburgh for the purpose of ascertaining the quantity of air that must pass periodically through a chamber occu- pied by 240 persons so as to enable those persons to remain for any length of time without suffering the slightest inconvenience from a tainted atmosphere, and he varied his experiments with less and lesser numbers. His calculations led him to provide an area of discharge for air of no less than fifty square feet, a far larger quantity than any one had ever imagined to be necessary, Sir Humphrey Davy having, it is said, provided an area of only one square foot in the same chamber for the House of Peers, and the Marquis de Chabannes nine square feet in the late cham- ber of the House of Commons. For the purpose of with- drawing air through so large a space, Dr. Reid had adequate means. The air in the first place passed through numerous apertures in the ceiling; it then entered a large main channel which descended perpendicularly against an outside wall and passed along an underground channel to a chamber in which was a furnace connected with an elevated chimney shaft built expressly in a piece of ground adjoining the building. No air was allowed to pass to the furnace except that which came from the house by the descending and underground channel. It was soon evident that the motive power of the furnace and chimney shaft were amply sufficient for the ventilation both of the chamber and other parts of the building, the air passing away with greater or less velocity according to the amount of fire burning in the shaft, and according as a certain door placed in the main channel was more or less opened, the latter means enabling the quantity of air escaping to be increased or checked instantaneously. It must be noted that Dr. Reid had no object in using a descending flue
ON VENTILATION AND HEAT. 31
for the air to pass to his furnace to be finally discharged by the shaft, beyond that of utilizing the means at his dis- posal by the best possible makeshift arrangement. He had thereby to incur a loss of power, and he recommended for new constructions, that the ventilating furnace shaft should form a part of the building with the fire burning above the level of the ceiling.
For the supply of a due quantity of fresh air to the House to replace that withdrawn, Dr. Reid had most elaborate arrangements, with a view to prevent the slightest incon- venience from draught or inequality of temperature. He desired that air should enter the House with the utmost possible diffusion. Instead of the twenty thousand holes of Sir Humphrey Davy, or whatever the number may have been, he had nearly a million. These holes were everywhere about the floor, in the upright portions of the members' seats, and in similar positions in the galleries. They were covered with a porous and elastic hair-cloth carpet, which vastly assisted diffusion. Between the floor of the House and the external atmosphere there were certain chambers of a highly useful nature. The fresh air first entered the lower chamber from Old Palace Yard, through the meshes of a veil, forty-two feet long and eighteen feet six inches deep, which served to exclude visible particles of dust or soot floating in the atmosphere, and which was so useful that, on one exceptional occasion, it was said to have retained no less than two hundred thousand particles on a single evening. The air in summer, when it did not require to be heated, traversed certain other chambers, and entered an equalising chamber below the flooring of the House, which was so constructed as to facilitate the spread- ing of the air equally to every portion that it might enter the House through the perforated floors and porous carpet, in all cases imperceptibly, and, as far as possible, with a uniform degree of force. It was not often that air thus
32 ON VENTILATION AND HEAT.
entered the House without other preparation. During the winter and a great portion of the spring, it of course had to be warmed. For this purpose the air after passing through the veil in the court-yard, was allowed to traverse ranges of hot-water pipes. Occasionally it had to undergo further treatment. In certain states of the atmosphere the air was unpleasantly dry, and, as its capacity for mois- ture was further increased on heat being imparted to it, Dr. Reid provided ample means for imparting moisture — as much as seventy gallons of water having been evaporated on a single evening. There were also con- trivances for cooling the air in hot weather, and for drying it when unpleasantly moist. Dr. Reid was not, however, satisfied with even all these provisions, for, to carry out his scheme with the utmost refinement, he dealt with another contingency, by means that would have never entered the conception of one less enthusiastic or less fertile in resource. The contingency is that which arises from a public chamber being exposed to considerable and sudden fluctuations in the number of persons present. It is familiar to every one that the presence of many persons in a building or chamber assists powerfully to warm it, in consequence of the temperature of the body exceeding considerably, as it does, that of the surrounding atmos- phere, and, it is a natural result that as a public room becomes emptied of its contents, there is a sensible reduction in the temperature of the air. This operates to the relief of those remaining when it happens that the atmosphere has hitherto felt close and offensive ; but, in the case of a chamber that is well ventilated, and where the warming arrangements are under such careful super- vision that the temperature of the air in the chamber does not exceed that which is generally agreeable, even when a large assembly is present, the effect of a considerable number of persons withdrawing is to leave an impression
ON VENTILATION AND HEAT.
33
of chilliness on those who remain. A great portion of the heating power is, in fact, suddenly abstracted. And thus it was often calculated to be at the House of Commons. A debate suddenly closing, a prolix speaker and other causes might suddenly relieve the benches of a great portion of their contents. The evident remedy for the evil was to increase the power of the heating apparatus below the House. This, however, could not be done instantaneously. It took a certain amount of time to increase the temperature of a large mass of hot-water pipes. Dr. Reid was able easily to regulate the quantity of air that flowed into the house by simply regulating the amount of passage way in his main air channel, by which the air flowed from above the ceiling to the ventilating shaft, and he desired, as far as it was practicable, to regu- late with equal rapidity the temperature of the air. He wished to satisfy completely the member who clung to his bench and those members whose presence was more ephemeral. His arrangement was to heat the air for the House to a temperature greater than it was actually re- quired, and to obtain the temperature he thought necessary at any moment by mixing it with air at a much lower temperature. He therefore had what he called his mixing chamber between the veil that admitted the air and excluded the dust in the court-yard, and the equalising chamber that distributed the air under the floor of the House. Dr. Reid had one door that admitted cold air into the mixing chamber and another door that admitted warm air, and he hoped, by simply regulating the opening of his doors and thus altering the proportions he admitted, to gain with great rapidity the exact temperature he desired. To what extent he succeeded with respect to this one point it would be impossible, without special experience, to say with precision, but it is impossible to doubt that the arrangement altogether was a most admirable one.
D
34 ON VENTILATION AND HEAT.
No less than sixty thousand cubic feet of air per minute were allowed on certain occasions to pass through the House, an amount of ventilation that was perfectly agree- able on a sultry day. Never before had a body of legis- lators so much science brought to their assistance to enable them to devote their energies to the good of their country. The preceding account by no means comprises all of Dr. Reid's providing. There was an open grating in Old Palace Yard communicating with a drain, which was capable sometimes of emitting foul air. This drain he controlled by making it communicate with his ventilating shaft. Every internal possible means of contamination had careful attention. In the lobbies he had mats and " Russian scrapers " liberally provided, that the members' boots might be relieved from dirt or dust by an involun- tary process, and, if he could not prevent emanations from the river when there was a low atmospheric pressure, or the wafting of impurities from gas works and other manufactories across the river, or the passing of barges laden with manure during hours of debate, or occasional emanations from a neighbouring churchyard, it was cer- tainly not from want of a will. If chemical preparations could have relieved the atmosphere of impurities, Dr. Reid was the man to endeavour to discover and apply them ; but what he considered most practicable was to have the power of taking his supply of fresh air from more than one quarter, so tha* if tainted at any time at one point, he might avail himself tff the other.
Dr. Reid did not succeed in his efforts without having obstacles to encounter^ resulting from a want of appre- ciation on the part of s6^rne members of the legislature. At any early period exception was taken to his arrange- ments, and among the parl? liamentary papers of the period are some humorous letters fry Sir Frederick Trench, who, with many others, was evidently afraid of too much
ON VENTILATION AND HEAT. 35
philosophy. Sir Frederick thought that the most simple and obvious remedies were the best, and instanced the ease with which Dr. Reid himself had relieved the House of inconvenience from n? se ; for, he said, " nobody sug- gested a carpet or doubl doors, or a less ponderous and noisy lock, till Dr. Reid aop ^ared."* The doctor succeeded in satisfying the good natured Sir Frederick, and so thoroughly successful was the system considered, that several years afterwards the strongest testimony was borne to it.
A committee reported, in 1846,
" The great improvement which Dr. Reid has affected in the atmosphere of the existing House of Commons can be appreciated by every member of the House, and your committee entirely concur in what they consider to be the general opinion in its favour."
Lord Sudeley, chairman of the building committee for the new Houses, said :
" The pestilential atmosphere of the House of Commons was notorious : its baneful effects on the health and energies of the members were painfully felt and admitted. Means from time to time were resorted to, to correct the evil, till scarcely a hope remained even that it could be lessened, and the most sanguine never dreamt that it could be cured, much less that the ventila- tion of the Houses could be brought to such a degree of perfec- tion as to defy the chills of winter and the heat of summer, or the effects of numbers, however great, congregated within the walls lessening its beneficial effects."
Dr. Arnott, in 1856, thus bore honorable testimony for his contemporary and countryman :
" Until the late House of Commons existed as ventilated by Dr. Reid, there never was in the world a room in which five hundred persons or more could sit for ten hours in the day, and
* The ponderous and noisy lock has disappeared, but it is probable the lock has not yet been constructed which will keep out members who are useless or worse than useless.
D 2
36 ON VENTILATION AND HEAT.
day after day, for long periods, not only with perfect security to health, but with singular comfort."
Such unequivocal success ensured the engagement of Dr. Reid's services for the new buildings. He removed from Edinburgh to London * to enter upon his formidable undertaking. An enormous pile of buildings, containing some hundreds of rooms, as well as the chambers of as- sembly, had to be provided for with respect to warming, ventilation, and the carrying off of the smoke from hundreds of chimneys by main out-lets. A portion of the arrange- ments fell to Sir Charles Barry, and a portion to Dr. Reid. It was of the highest importance that these gentlemen should work amicably together. Whatever Dr. Reid contemplated was inextricably mixed up with the general construction of the building. Dr. Reid was far from being the man to spare personal attention to every point of detail, and he was not therefore to be the man to yield if the fullest possible information was withheld from him. Whether he was too exacting in his demands, or whether Sir Charles Barry was unsympathising and unyielding, would be a thankless subject of enquiry, but it is certain that there were unfortunate matters of difference which extended over nearly the whole period of the construction of the building. There was no authority competent to interfere and pronounce decisively on the points at issue, and the result was of course disastrous. Dr. Reid went on loudly protesting, and at last an architect was appointed as arbitrator, to enquire fully into the whole business. Dr. Reid, Sir Charles Barry, and many other witnesses con- tributed an enormous mass of evidence, which was pub- lished by authority, and the result as regards the House of
* The writer remembers Dr. Reid at about this period, nearly forty years since, when Dr. Reid gave practical demonstrations on chemistry to a class of pupils at Willis's rooms, St. James's. The pupils assisted in the experiments.
ON VENTILATION AND HEAT. 37
Peers, and the greater portion of the entire building was, that a certain noble lord succeeded by a motion in reliev- ing Dr. Reid of any further responsibility with respect to them, and the warming and ventilating arrangements for those portions devolved entirely on Sir Charles Barry. Dr. Reid retained his appointment with respect to the House of Commons and appertaining parts, but an im- provement was effected henceforth by the appointment of a special officer, from the office of the architect, to be always at Dr. Reid's service, for the purpose of providing him with the information he wanted, and to carry out his plans. If no new subject of complaint had arisen, few would happily have heard anything more of the differences be- tween Dr. Reid and Sir Charles Barry, but, unfortunately, after the building was occupied, there were great com- plaints of the ventilation. A committee to enquire into the subject was appointed in the House of Commons, who found it necessary entirely to decline to go into the old subjects of contention. The evidence furnished explained fully the system which Dr. Reid set in operation, and render it clear that whatever defects might have existed, Dr. Reid approached his subject, as before, with the com- prehensiveness and boldness of a great inventor. Not satisfied with the considerable success he had had at the temporary chamber, he aimed at yet higher things. There, it will be remembered, he took his supply of air from a court-yard, but now, he sought to take it from above by making it descend one of the high towers into a vaulted chamber, where he provided a powerful fan-wheel worked by a steam-engine to propel the air into the chambers for heating, drying, moistening, mixing or equalizing, before it entered the house through a perforated floor and hair- cloth carpet. A constant descent of air in the tower was occasioned by the law of gravity, as soon as the propelling machinery was set in motion.
38 ON VENTILATION AND HEAT.
To withdraw vitiated air, Dr. Reid had, as before, a large coke fire, but he arranged it in one of the towers of the building above the level of the ceiling of the chamber, the air escaping at openings in the panels into a chamber above, from which it passed to the ventilating shaft. The new system therefore differed from the old one, chiefly by the vitiated air being discharged from the ceiling without having subsequently to descend, and by fresh air being taken from a high level instead of a low one. It was not, however, solely to ensure an adequate supply of air from above that Dr. Reid introduced his powerful propelling machinery. He had another very important object in view. He sought to introduce the novel feature of main- taining the air in the House at a higher pressure than that situated without, so that instead of air being likely to leak into the house around doors and windows, occasioning draughts, the tendency should be exactly the other way. Such a feature, so characteristic of Dr. Reid, could only be obtained with mechanical assistance. It may be thought that by taking air from a high level, and seeking to prevent draughts at a lower level, Dr. Reid did enough to save the House from sewer gases, emanations from the river, or from manufactories, but if he could have had his way, he would have done more. He wished to have the choice of two towers situated a considerable distance apart, so that if one were at any state of the wind afte :ted by emanations from a certain quarter, he -might tak lis supply of air from the other, and if both were in evil rase he wished to be able to take air from one of the court- /ards.
This was going too far unquestionably. If Parliament would not suppress nuisances in its own neighbourhood, it might be left to endure them, for the personal experience of our legislators might be useful to hasten legislation on great sanitary questions. It was one result of Dr. Reid's previous success, that he had trained the House to become
ON VENTILATION AND HEAT. 39
fastidious. Men, who would have shrunk with disgust from the old chambers described by Lord Sudeley, soon began to ascribe the slightest personal inconvenience to the imperfect ventilation. Much as Dr. Reid was capable of doing, and willing as he was to apply to the most elabo- rate extent the science at his command, there were some things altogether beyond his powers. He could not satisfy both the man who liked a temperature of seventy degrees, and the one who was satisfied with fifty-five. He could not provide that the atmosphere should be equally agree- able to the member who entered the House after a sharp walk, and one who had been sitting in it for a couple of hours ; and he could not satisfy the man who joined the chorus of grumblers without having any understanding on the subject. There was a great complaint of dust, which it was said fell from the members' boots* through the hair-cloth carpet and perforated iron floor, and was raised again by the fresh air coming in, and then carried to the members' lungs. The chamber below was therefore kept carefully clean, and the carpet walked over was taken up and cleansed daily. But if unreasonable complaints had stood alone, they would probably have been silenced. Unfortunately there was some sound reason for dissatis- faction if the temporary chamber so admirably warmed and ventilated was taken as a standard of comparison. There were, at certain times, conspicuous inequalities of temperature in different parts of the House, and in some parts disagreeable currents were complained of, especially in the reporters' gallery. The committee soon discovered that a division of the ventilating arrangements of the entire building between Dr. Reid and Sir Charles Barry, as effected by the motion in the House of Peers, together with the unfortunate state of the relations subsisting
* Nothing appears to be heard of dust now-a-days, except from the lungs.
4O ON VENTILATION AND HEAT.
between those two gentlemen, had operated disastrously. Dr. Reid required for the full success of his scheme to have a certain control over the House and all the ap- proaches to it, but though this might account for many defects in various portions of the building, there appeared hardly room to doubt that he failed to some extent in the calculations upon which he based his elaborate con- trivance. The very thing Dr. Reid had striven for he failed to get. Instead of forcing such an abundant supply of air into the House that draughts could only occur from the House outwards, the reverse was the fact, and he had a deficiency of pressure, the consequence being that the House was in much the same position as any ordinary room where a fire is kept burning, and fresh air cannot enter with sufficient freedom — that is, there was sometimes a sensation of closeness, and there were sensible currents in certain parts.
Whatever deficiencies existed were traced out carefully by Mr. Goldsworthy Gurney, at the request of the com- mittee, and laid before them in special reports. Dr. Reid made the best he could of his case, but, if he had erred to some extent with reference to the size of his air channels or the power of his fan-wheel, he was naturally loth to admit it, for everyone was so heartily tired of the whole subject, that it was perhaps hardly possible for the com- mittee to show him much mercy. He was allowed to make certain alterations, which were not considered sufficiently satisfactory, and the inevitable end came. Dr. Reid was removed from his position, and went sub- sequently to the United States of America, where he died. At the present moment the system of ventilation at the House of Commons consists of an extracting power for the vitiated air from above the ceiling, and the free entrance of fresh air from a low level, a system identical in its main essentials with that instituted by Dr. Reid at the tern-
ON VENTILATION AND HEAT. 41
porary chamber. The system of bringing fresh air down one of the towers, and propelling it by machinery, has been long entirely dispensed with.
It is impossible for any one not to sympathise con- siderably with Dr. Reid in his fallen position, for, to a man of such activity and earnestness, the blow must have been a very severe one. Where he erred was unquestionably from excess of zeal. He was not the man to be satisfied with a small success, and to regard a respectable income and certain honors as his highest reward. He took up the subject of ventilation when it was in a very crude state, and he applied himself with unwearied industry to such consideration both of the leading points and details as might raise it to the dignity of a science. Great in- ventors have risen to eminence often after years of dreary toil, and all who have a just conception of an inventor's career are perfectly aware that it is only by a steady over- coming of difficulties and determined perseverance, in spite of failures or pecuniary loss, that success is finally obtained. It would, therefore, be most unreasonable if the name of Dr. Reid should suffer because his labors were not free from the imperfection which attends every- thing human.
Dr. Reid's principal literary contribution was a volume published in 1844, called ' Illustrations of Ventilation/ the most valuable and suggestive book on the subject still existing in our language. Being appointed in 1843 one of the commissioners to enquire into the state of towns and populous districts, he contributed an able treatise on the state of the Northern Counties, accompanied by an excellent series of colored plates illustrative of ventilation, which were published in the voluminous report of the commissioners. His latest contributions were a publi- cation issued at New York 'On the Ventilation of American Dwellings/ which did not manifest any offensive spirit
42 ON VENTILATION AND HEAT.
towards his detractors, and a revised article on Ventilation in a late edition of the ' Encyclopaedia Brittanica.' Dr. Reid ventilated St. George's Hall at Liverpool and very many public buildings in this country. He made many suggestions with respect to the ventilation of dwellings, particularly the characteristic one that wherever the cost could be maintained a special ventilating shaft should be constructed, in which a fire was to be kept burning, and which should be in communication with every chamber or closet, and allow of stagnant air nowhere. He taught much both by writing and practice, and showed his genuine power both in his successes and in his more daring attempt.
On the cessation of Dr. Reid's labors, divided respon- sibility was henceforth avoided. The warming and ven- tilating arrangements were placed under the charge of an officer of the board of works, who had no power to make alterations less authorised. It was resolved to relieve the members of some of their troubles. The portions of the place commonly walked over were made impervious, so that there was less chance of dust from their boots being carried to their lungs. Free access for the admission of air was given at other points, so that any sensation of closeness and disagreeable draughts might be avoided. Matters thus continued till 1854, when, in consequence of some members being still dissatisfied, a new committee was appointed. Mr. Goldsworthy Gurney,* who had been introduced into the Houses of Parliament many years before by Sir Charles Barry, and had been occasionally employed in the building with reference to the lighting, found his services to be again in request on the subject of the ventilation. He drew up one more report containing several recommendations. He first recommended that the committee should carry out the general desire of making
* Sir Goldsworthy Gurney, now deceased.
ON VENTILATION AND HEAT.
43
the windows to open. Dr. Reid and Sir Charles Barry had agreed in avoiding this, the first considering it to be totally unnecessary and calculated possibly to interfere with his system, and the latter for constructional or archi- tectural purposes. Mr. Gurney next recommended "that the present cumbrous and complicated mass of warming apparatus be removed, and that a more simple and manageable arrangement be made." Mr. Gurney, it appears, preferred his system of heating by steam. The third recommendation was " that the system of ventilation be changed to the downward system." In this he followed plans which have been much in favor on the Continent. It has been often considered that in hospitals, criminal courts, &c., the emanations from the bodies of sick, un- healthy or unclean persons were less perceptible when the general tendency of the air in a chamber was to descend instead of rising, and that therefore the system of intro- ducing fresh air at or near the ceiling, and withdrawing it at or near the floor, was preferable for such places. The open mind of Dr. Reid perceived its probable advantages under certain circumstances. In fact, a downward system of ventilation operates in every dwelling where the air comes in at the top of a window and the escape is by the fireplace. Mr. Gurney carried his theories in support of the system very far. He considered that impure emana- tions from the body fall to the ground instead of per« meating the atmosphere, and that at the floor was the proper position for the escape of vitiated air. He in- stanced repeatedly, in his various examinations, his notions relating to dogs scenting the ground and the case of bloodhounds.
Mr. Gurney also strongly advocated the use of the steam-jet for assisting to withdraw vitiated air into the many ventilating shafts of the building. The steam-jet consisted of a small tube from which a rush of steam
44 ON VENTILATION AND HEAT.
acted (by its propelling power and the heat it communi- cated to the air in the shaft) to create or accelerate an upward current, the air in the shaft being continually supplied from the rooms with which it was in communica- tion. The special object of the steam -jet was to supersede to some extent the use of fires for ventilation. At last Mr. Gurney was urged to take on himself the charge of effecting alterations and to undertake the general super- intendence thereafter, to which he consented, deprecating at the same time the notion of his being actuated by the desire of gain, and because he had independent means and a desire to oblige his friends. It appeared by Mr. Gurney's evidence, that he was in early life a surgeon in Argyll Street, but was enabled to retire from his profession and devote his attention to some scientific subjects. He in- troduced the Bude-light and different systems of lighting in the Houses of Parliament, alluding to which, and his propositions for the ventilation, he said, that " he had had a child, and he had set him going, and now he wished to see this go." Sir Golds worthy Gurney's motives were of course disinterested, but it may be permitted to regret that his paternal instincts have not found further scope, as no one has had such excellent opportunities as himself of making useful observations for the benefit of the public and the constructors of large buildings. Mr. Gurney abandoned Dr. Reid's system of taking fresh air from the top of the clock tower. He removed the propelling machinery. He introduced fresh air in one of the court- yards from about a level with the ground, and he sub- stituted a system of heating by steam for the previous arrangement of heating by hot water. The downward system of ventilation has not been introduced, but it appears that Mr. Gurney has successfully applied it else- where. In the new system of heating, Mr. Gurney applied a principle for which a patent was taken out in 1845 by
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45
the late Mr. Silvester, a warming and ventilating engineer. Mr. Silvester proposed to increase the exterior radiating surface of a close stove, by means of several leaves of iron placed parallel to each other, and about an inch apart. The effect of the iron leaves was not of course to increase the heating power of the stove, but to gain an increased surface of iron at the cost of reducing its temperature. The advantage was that the stove produced a more whole- some atmosphere than if there had been a possibility of overheated iron, while the power of the stove for warming purposes was very little impaired. The same principle, but with some modification as regards size and proximity, Mr. Gurney applied to the exterior of steam pipes, and termed " Gurney's batteries." These " batteries " would be useless for ordinary hot water pipes, which do not be- come overheated, but they may be beneficially used with steam pipes. Sir Goldsworthy Gurney, some years ago, resigned his appointment as " ventilator " to the Houses of Parliament, and his place is now filled by Dr. Percy. In a report presented to the House of Com- mons, Dr. Percy gave many interesting particulars of the system of ventilation in operation. He said, with reference to the theory of bodily vapor sinking to the floor, that " we know nothing either of the chemical or physical nature of this matter ; and it is therefore vain, and may be mischievous to attempt to found symptoms of ventilation on what are at present mere assumptions," and with reference to ventilation by the steam-jet, " that Sir Goldsworthy Gurney long before he resigned his appoint- ment had completely discarded it."
The multiplicity of the arrangements in connection with ventilation, smoke, &c., may be judged of by the following extract :
" There are many hundreds of air-courses under as well as above ground, beneath floors, in walls, over ceilings and in roofs ;
46 ON VENTILATION AND HEAT.
some for supplying cold air, others for supplying warm air, and others again for carrying off vitiated air ; there are air-valves in every part of the building ; there are enormous smoke flues run- ning horizontally within and immediately under the roofs, with hundreds of chimneys in communication ; there are, it is asserted, steam pipes of which the aggregate length is about fifteen miles, and about 1,200 stock-cocks and valves connected with these pipes ; and there is a multitude of holes and crannies as intricate and tortuous as the windings of a rabbit warren."
In such a building it is not surprising that Dr. Percy should still find room for improvement.
There is yet one whose name has been but little asso- ciated with any system of ventilation, and who, without being a practitioner, has made certain suggestions. About five and forty years since, when the attention of observing men was generally called to the deplorable results which arose from the concentration of the masses of the working classes in large towns, without there being any adequate provision for their decency and health, many writers of ability contributed to public enlightenment on such sub- jects,and among them was Dr. Neil Arnott,aphysician, who was present at the death-bed of Napoleon the First. Dr. Arnott published in 1828 the first edition of his ' Elements of Physics/ a book whose familiar illustrations and clear language rendered the causes of common phenomena plain to the most ordinary reader, and that at a time when little or nothing was known of physical science by men who were called well-educated. The publication was a popular one, and went through several editions. Subsequently, when Dr. Arnott interested himself in the subjects of warming and ventilation, he received a large amount of attention. In 1835 he attempted, with a certain amount of success, to introduce the continental system of warming apartments by means of close stoves, but so little did Dr. Arnott at that period appreciate the necessity of ventilating the chambers of our dwellings, that he expressed his
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opinion that an apartment would be sufficiently well ven- tilated even with one of his stoves in use, which allowed exceedingly little air to enter the chimney, and he in- stanced the case of Russia and other continental countries, where people universally used stoves, and yet did not com- plain of the ventilation. He considered that the apertures around doors and windows were sufficient for ventilation, except in a room holding a crowded company, when a window might be opened.* Dr. Arnott, like other able men, had both to live and learn. He since re- peated in substance the teachings of the Marquis de Cha- bannes, and introduced a ventilator to be fixed in the chimney, figs. 9 and 10, below the ceiling, for the purpose of utilizing the chimney-draught from the upper part of a room. The Marquis provided a chain or wire wherewith to close his ventilator, but Dr. Arnott improved on this by so balancing the door that when air passed from the room to the chimney, the door opened spontaneously, and when there was no pressure from within, or a reverse pressure, the door remained closed. As Dr. Arnott has never ex- pressed any acknowledgment to his predecessor, it must be supposed that he did consider himself to have profited by his teachings.
In 1854, Dr. Arnott published a revised and extended edition of his book on warming, wherein he urged fully the advantages of his ventilator, and of his other contrivances. He now took up the question of ventilating public build- ings, and advocated for such places the use of a modifica- tion of Dr. Hales's bellows. Instead of the heavy flaps of wood, suspended by leathern hinges as valves to open and close the air apertures, Dr. Arnott was able to make use of the modern refinements of wire gauze to cover the
* See ' Arnott on Warming and Ventilating, with directions for making and using the Thermometer Stove/ &c. Longman, 1838. Page 66, also at page 76.
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openings, and oiled silk suspended behind the gauze, to open and close with the pressure of the air. In one conspicuous instance where Dr. Arnott's services were invited, he arranged a system of working his bellows by means of the pressure of a high column of water, which dispensed with hand labor. Dr. Arnott intimated that Dr. Hales did not make his channels for the passage of air sufficiently large, but one thing was done by Dr. Hales which Dr. Arnott unfortunately neglected. Dr. Hales explained by what means he could ventilate wards at a distance from his bellows, but it is impossible to know from Dr. Arnott's book in what way he would effect the same object. Possibly Dr. Arnott confined his apparatus to benefit the hall and staircase of a building. In the course of the investigations on the ventilation of the House of Commons, an amusing incident occurred, illus- trative of conflicting opinions with respect to different systems. A number of monkeys had died some time previously at the Zoological Gardens. Dr. Arnott had attributed the calamity to the want of ventilation from above in the monkey-house, and said they were living under an extinguisher. Mr. Gurney, however believed in downward ventilation, and ascribed their disease to over-heated metal. Dr. Arnott, it appears, believed that in ordinary apartments pure air was only enjoyed by dogs, cats and children till they gained the height of the fire-place. Mr. Gurney, on the contrary, evidently thought that the dogs and cats were the worst off. Such difference of opinion shows unquestionably how necessary it is that systems of ventilation should be founded on the demonstrations of science, and not upon hypotheses.
Of the various systems of ventilation which have been adopted, blowing- wheels or ventilating bellows are now scarcely known. The very efficacious principle so long used unconsciously of withdrawing vitiated air by means
ON VENTILATION AND HEAT. 49
of chimney draught, aided by a fire, is most deservedly in favor. The usual method is to withdraw the air from above, and to allow the fresh air, whether warmed or not, to enter spontaneously at a lower level, discomfort being avoided according to the excellence of the arrangements provided for diffusing the air. Sometimes the reverse system has been used, and the suction power working from below has made it possible for the fresh air to come from above. Much detail respecting the various systems will be found in Dr. Reid's ' Illustrations of the Theory and Practice of Ventilation' (Longman, 1844); *n Mr. Ritchie's ' Treatise on Ventilation, Natural and Artificial/ (Lockwood, 1862), and in General Morin's ' Etudes sur la Ventilation,' 2 tomes, (Paris: Hachette, 1863), and a variety of useful information in the compilations of Ber- nan, (' History and Art of Warming and Ventilating,' &c. Bell & Daldy, 1845), and Mr. Charles Tomlinson, (' Rudi- mentary Treatise on Warming and Ventilation.' Third Edition. Virtue, 1864.)
Since the writing of this first chapter the writer has practically but little to add. Allusions to Captain Galton's grate, and to the Tobin system, will be found further on.
50 ON VENTILATION AND HEAT.
CHAPTER II.
ON SOME SIMPLE APPLIANCES FOR VENTILATING DWELLING-HOUSES.
THE considerable amount of attention which was devoted to the ventilation of the Houses of Parlia- ment operated most beneficially in manifesting the possi- bility of effective systems being applied to other public buildings. The necessity for much enlightenment on the subject was very great. So much had the subject been neglected, that no special provision was usually made by our architects for ventilation ; an encyclopaedia of archi- tecture did not" even contain the word within it; any aperture to admit air was liable to be taxed as if it were a window to admit light, and, if it was for a long period considered hopeless to preserve the atmosphere of the House of Commons in a state of purity, we may be sure that our theatres, hospitals, poor-houses, prisons and chambers of justice were in most evil case. It was the temporary chamber of the House of Commons, the one formerly used by the House of Peers, which afforded the first notable instance of what science could really effect, and furnished the practitioner with practical and elaborate demonstrations by the aid of which he might apply simple and effective systems in less complicated cases, instead of
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having to attempt the more difficult process of improving on such imperfect methods as had been occasionally used. Attention to ventilation has been further stimulated by those revelations of the deplorable condition of the dwel- lings of the laboring population with which many persons have in past years been familiar. It is to a considerable extent, a subject of concern and regret, that the enor- mous advance which our country has made during the present century in manufacturing skill and in wealth, and which has brought a great addition of the comforts or luxuries of life to many hundreds of thousands, cannot be considered to have profited to a satisfactory or a corres- ponding extent the skilled and unskilled labor upon which our success and its benefits have so largely de- pended. As working-men and their families have increased in number, no adequate provision has been made for them. All large centres of industry have contained dis- tricts, which, for concentration of inhabitants, filth, ab- sence of decency and abject wretchedness, could hardly have been equalled by any other country or time. The evils, a few years since, were found to be so appalling and so dishonoring, that the national conscience was much roused — The Government was forced to act — Commissions were appointed — Reports and masses of evidence were published. A Board of Health was established, and useful acts passed the Legislature which dealt with the questions of crowded lodging-houses, drainage, crowded church- yards, supply of water, and other matters connected with health and decency. It soon forced itself on the attention of those who were actively engaged in investigations, that existing means did not suffice to permit a proper change of atmosphere in the confined and crowded dwellings of the poor. The evidence of the senses was far more than sufficient. Sickness, disease, death and evil habits deve- loped or fostered in a great measure by the evil conditions
E 2
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in which the helpless occupants were placed, were found to be invariably associated with dilapidated dwellings that were never touched by paint or whitewash, with windows that would not open, with rooms crowded with persons of both sexes and of all ages, and certain other disgusting causes of contamination. Alarmingly, but most mercifully, came certain epidemics, which found their congenial home where impure air and impure water ever accompanied filth and disease. The cholera visitations of 1832, 1848 and 1854, in particular, acted a terrifying and therefore useful part in exciting the attention of thousands, and many began happily to be careful about breathing pure air with the instinct of self-preservation. The question then arose, whether the air of any enclosed place which was liable to be contaminated by the body's exhalations passed away with sufficient rapidity to be perfectly innocuous to the inmates. It was successfully urged that if in theatres, hospitals, &c., the air became so contaminated by the presence of many persons as to produce great incon- venience, and if the foul condition of dwellings in the poorer districts was the means of developing baneful diseases, and of constantly exercising a depressing or deteriorating influence on the condition of mind and body, that unquestionable evil, though not so immediately per- ceptible, must result from the retention within our dwel- lings of even slightly contaminated air. A case of the destruction of much human life in consequence of many persons having been forcibly confined together for many hours in the cabin of a steam vessel sailing from Ireland to Liverpool, came to furnish a practical proof that poisoned air may be as bad as no air at all. The old open fireplace was fast going out of use — contracted grates were substituted. Coal gas, often very impure, was being largely introduced for lighting, and the natural result followed, that the ventilation of dwellings began to
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53
be regarded as a practical necessity. When the Marquis de Chabannes recommended the ventilation of bed- chambers, he found few or no listeners, but, some thirty years later, when the subject was better understood, Dr. Reid, Dr. Arnott and other writers, countenanced atten- tion to the subject with considerable success. The inevi- table result followed, that numerous applicants appeared year after year at the Patent Office to ask for the monopoly of the use of some suggestion that had occurred to them for letting fresh air into a chamber, or contami- nated air pass out, and so familiar has the subject become, that an old use of the term to ventilate, used in some figurative sense, seems to be quite a favorite expression among occasional writers to newspapers who wish to discuss some one or other of our administrative or social deficiencies. Of the various schemes which have been proposed, some have received attention and are in frequent use ; others of not less utility have been insufficiently put forward; but before reviewing those which may appear worthy of note, it may be expedient to attempt a few general considerations on the ventilation of dwellings, both for the purpose of facilitating a proper conception of the relative value of different methods, and of leading to conclusions as to the nature of the special provisions which might advantageously form part of future constructions.
It is familiar to the general reader that a man in ordi- nary health makes about twelve hundred inspirations per hour, and that a large proportion of the air which enters the body becomes decomposed, that the oxygen unites with carbon, produces heat, and forms the poisonous carbonic acid gas which is constantly discharged both from the skin and the lungs. An atmosphere rendered deleterious by the presence of this gas alone, as in the burning of char- coal, does not give warning to the sense of smell, but it occasions great oppression, and, under certain circum-
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stances, death. When discharged from the body, it is accompanied by certain vapor, which is said to be of unknown composition, but which, unless largely diluted with air, is apt to manifest its presence offensively in the manner familiar to every one who has ever entered a crowded and unventilated space, and it gives thereby the useful warning that the air is quite unfit to be breathed. In the open air abundant provision exists for the disper- sion of vitiated air and the supply of fresh. That which a man vitiates is soon afar from him, whether he be at rest or in motion, and that which would be poison to him becomes food to the vegetable creation, which takes carbonic acid from the atmosphere, decomposes it, retains the carbon, and returns the oxygen, so that, by such com- pensatory process the air surrounding our globe is main- tained in a condition of suitability for both animal and vegetable life, and, for aught we can tell, with our not unlimited powers of observation and comprehension, such compensatory process might be adequate in the eventuality of this world's possessing a population infinitely greater in number than at present.
The means which thus relieve a man of concern with respect to the air he breathes without his dwelling, may also be effectual with respect to myriads of human beings congregated in our most populated cities. The incessant change in the temperature of every portion of the earth's surface, occasioned by the earth's motion on its axis and its revolution round the sun, causes incessant disturbance of the atmosphere by which the earth is surrounded, and hence the constant dispersion of the air which has become unfit for human life. We are conscious of aerial disturbance when it is sufficiently violent to be felt as a wind or a breeze, but we are not conscious of the motion by which we are surrounded at every instant of time, and which, there can- not be the slightest doubt, operates to an extent altogether
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beyond our powers of investigation or conception. It can be easily shown that what we call a stagnant atmosphere is simply one which gives us no indication of its being in motion. We displace, unconsciously, a considerable quantity of air with every movement of the body. We are not directly conscious of the currents which pass in and out of the mouth. The warm breath ejected from the lungs cannot usually be traced at a few inches from the mouth. A door must be closed with a certain rapidity for us to be conscious of its displacement of air. A fan, for the same reason, must be moved quickly to occasion relief, and an odour becomes dispersed in a chamber by means of imperceptible currents, with such inconceivable rapidity, that we may readily credit the assertion of Dr. Reid, that many thousand currents are occasioned by burning gas in an argand gas burner. Such considera- tions may enable us, in some measure, to conceive how the never-ceasing variation of temperature and pressure in the atmosphere insures the extensive spread of con- taminated air, and happily, thereby, its dilution and dis- persion ; and it may hence appear that in aerial motion, as in other things, Nature operates for our benefit, both with manifest power and with silent subtlety, and that it becomes our chief concern to beware that we do not exclude ourselves in any measure from her beneficent provisions.
Though in our open streets many hundred thousand inhabitants may not appreciably contaminate the restless ocean of air in which they are immersed, it is an undoubted fact that the air of large towns does not afford the exhilara- tion or maintain the high state of health with which many may be familiar in the country. By various processes of manufacture in certain districts, and by the collection and retention of putrifying matter, we often contaminate large volumes of air to an extent which any amount of motion in
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the atmosphere cannot remedy. The poison becomes diluted, widely dispersed, and therefore to a great extent, rendered innocuous, but it still gives us warning of its hurtful nature. Our remedy for such evil is invariably to require that injurious processes should never be carried on in populated districts, and that matter which might be noxious to animal life should never be retained within or near our dwellings, except under strict precautions, but, as far as possible, be incessantly utilized.
Though, however, external causes of contamination were entirely removed or avoided, it is still probable that some difference would be found to exist between the health-giving power of air in urban and in suburban or country districts. Though the air in towns may often be technically pure, there is less sensible motion than in open districts. Such motion, there can be no doubt, largely stimulates the animal functions and promotes health. It appears, also, that the electric condition of air in the country differs considerably from that in the confined quarters of towns, and that a difference, with respect to invigorating properties, is often to be traced to this cause. Upon this point science has much to discover, but the bodily sensations of the healthy may suffice to indicate that free movement of air should invariably be facilitated by straight and continuous channels of communication, and that such desirability should be constantly regarded in the arrangement of new districts for building purposes, and in any possible rearrangement of those already occupied.
If a free circulation of air in our streets removes impuri- ties and is otherwise conducive to health, it is necessarily of great moment that such circulation should extend to the enclosed structures which protect us from wind, rain and cold, and in which most persons spend the greater portion of their existence. That the change of air in dwellings is often manifestly insufficient is familiar to every one
ON VENTILATION AND HEAT. 57
who enters an unventilated bed room, dining room, sick chamber, room where gas is burnt, or where many persons remain together above a very limited space of time. The air in any chamber, of course never continues entirely unchanged. The forces which operate so incessantly without do not leave unaffected the air within the most carefully closed building. Internal and external tempera- ture are never exactly the same. The temperature within a building itself is never uniform, and there is, consequently, incessant motion, occasioned by difference of pressure, with respect to a building or a chamber and the external atmosphere, with respect to one portion of a building and another, and with respect to one portion of a chamber and another; and all openings existing around doors and win- dows, openings between floor boards, open chimneys, key- holes, and even porous material used in construction, afford facilities for the spontaneous interchange of air.
In the summer, when the difference of temperature is inconsiderable, the interchange is not always very per- ceptible, and we may therefore freely open doors or win- dows without inconvenience, but, in winter we have, on the contrary, often to check the impetuosity with which air would enter at very restricted openings. The great dif- ference in this respect is but partially due to the greater difference in temperature, and is chiefly owing to our use of open fireplaces, which in addition to their express purpose of providing warmth and removing smoke, have an accessory advantage which should never be lightly regarded. The air which supports combustion, and that which becomes heated and expanded by contact with the fire, or proximity to it, passes from the room and ascends the chimney with rapidity. The withdrawal of air rapidly effects a diminution of pressure in every portion of the apartment, and there ensues a rapid entrance of air at any openings, wherever situated, and a far greater amount
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of general disturbance in the atmosphere than when no fire is burning. Our fires become consequently powerful ventilators, which rapidly withdraw and discharge the air of our rooms, and command the constant entrance of fresh air around windows and doors in place of the gentle inter- change we should obtain without them.
The use of chimney openings is far from being confined to the time when fires are actually burning. It is gene- rally found that the heat communicated to chimneys by the constant ascent of warm air is such as to insure an upward current long after the fires are extinguished. When chimneys are built in party-walls, an ascending current is often observed even in summer. Sometimes there are double currents, air from the room passing away and the cooler air of the chimney entering the room, and occasionally a strong descending current is the only one perceptible. So much, indeed, is an open fireplace known to influence the change of air in an occuped apartment, that we naturally shrink with repulsion from the close atmosphere of a bed-chamber not provided with a chimney, or in which the aperture has been foolishly closed.
The motion of air in rooms becomes further compli- cated by the varying intensity of the fire, by the variation in the temperature communicated by the fire to different portions of a room, by the amount of window surface, by the difference in the temperature of the walls according as they may be partition or external walls, and, in the latter case, face the north, east, south or west ; by the heat of the body and by its movement, by the constant inhala- tion of air and its discharge at a higher temperature, by the demand made in the combustion of gas and candles, and by the heat those substances communicate. It is hence evident that the circulation of air in houses is a very complicated matter, and one that if fully investigated
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would be sufficiently abstruse to tax considerable powers and the most refined means of observation. Dr. Reid's experiments, extending over many years, enabled him to throw much light on the subject without exhausting it ; and in the parliamentary report on the Warming and Ventilation of Dwellings, issued in 1857, the results of certain useful experiments were given, which are of con- siderable utility both from the information they convey and from the distrust they awaken as to the value of theories, by whomsoever propounded, that are not based upon systematic observation.
In the absence of conclusions drawn from elaborate investigations, we must endeavour to seek the assistance of a little wholesome common sense. The first point to consider is whether, under ordinary circumstances, we require any further provision for ventilation than what is furnished by fireplaces, doors and windows. Many writers, to elucidate this point, have endeavoured to estimate the minimum quantity of air per individual that should enter an apartment in a given time. Dr. Arnott, many years since, thought that " to be safe" there should be " a ven- tilation supply of from two to three cubic feet per minute." Dr, Reid, who, it has been seen based his opinions upon elaborate experiments, recommended ten feet, but in sultry weather at the House of Commons, provided much more. Others have suggested fifteen or twenty feet, and a late writer, Dr. Percy, prefers thirty- three feet, but expresses his approval of General Morin's safe but expansive notion that as much fresh air should be provided as can be borne without inconvenience. This last suggestion would involve the introduction of much more than twenty cubic feet per individual, provided there
* " Arnott on Warming and Ventilating, with directions for making and using the Thermometer-Stove/' 1838. Page 66.
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were careful provisions for ensuring imperceptible move- ment in the air.
There cannot be the slightest doubt that in the cham- bers of our dwellings the change of air is very often such as to satisfy the fullest requirement. In mild or warm weather, when windows or doors are opened, and in cold weather, when so powerful a ventilator as the open fire is in use, there is little need for apprehension, provided a room is not occupied continuously by many persons, and that gas is not burnt. The amount of air which escapes by a chimney, in fact, frequently occasions inconvenience from the unpleasant draughts which traverse the room, so that what is then required with respect to ventilation is to check its amount rather than to increase it. Our rooms, however, are very commonly differently circumstanced. They are sometimes appropriated for the use of many per- sons, or entirely closed and used continuously as in the case of bed-rooms, and, to mention other particular instances, in the case of dining-rooms, smoking-rooms, school-rooms, work-rooms, and any place where gas is burnt, they com- monly proclaim their want with respect to ventilation in a manner not to be mistaken. Whatever may be the amount of interchange, a question impossible to arrive at except approximately and indirectly, it is not sufficient for healthy purposes. In numerous other cases, and in any closed room where no fire is burning, it is often not evident to the senses as to whether the ventilation is sufficiently perfect or not, and there may appear, therefore, reasonable room for hesitation as to the proper course to be adopted. In cases of doubt, however, the safest course is often clearly indicated, and if we consider the rapidity with which impure emanations become dispersed, and that animal vapor must pervade the air to a certain extent before we can become conscious of it, it will not appear unreasonable to those who value healthy habits, and wish
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as far as possible to breathe untainted air, to introduce in their dwellings as liberal a supply of fresh air as can be obtained without discomfort.
It may not be readily apparent to every one what it is that such a conclusion really involves. Many would be disposed to judge of the quantity of fresh air they could bear by their familiarity with rooms that in winter are justly called draughty. It is generally conceived that such rooms admit too much air. Sometimes this is actually the case, but sometimes it is not so. Whenever the chimney fire-place is large and open, the quantity of air it allows to escape often occasions so much draught as to produce inconvenience. The passage of air up the chimney in that case requires to be checked. For a room to be draughty, that is insufficiently supplied with air, may appear to some a paradox, but the explanation is simple enough. If, when a fire is burning, as much air cannot readily enter the room as passes away by the chimney, the pressure of air in the room becomes reduced, there is a disagreeable sen- sation of closeness, and, wherever there are openings, such as around doors and windows, the air rushes in with great violence in obedience to the low state of pressure of the air of the room. On opening the door, the pressure be- comes restored, the disagreeable closeness is removed, and draughts in positions contiguous to the windows are less offensive. A proper supply of air, therefore, so admitted as not to occasion inconvenience might enable such a room to be occupied by any person with comfort.
To introduce imperceptibly into a room all the air that is required both for ventilation and chimney draught, is not a thing to be very easily effected. Speaking generally, it may be said that if draught over the floor to the fire is checked by allowing air to enter in winter in proximity to the fire-place ; if the apertures used for admitting air are very small; if they are dispersed over a certain amount of
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surface, and if they are removed from proximity to any person, there can be no perceptible draught. The most elaborate arrangement that has been yet contrived is the one adopted by Dr. Reid at the House of Commons, where, as will be remembered, he introduced the fresh air warmed in winter through innumerable apertures in the floor, and withdrew the air through numerous apertures in the ceiling, endeavouring to insure with a general ascent of the whole body of air equal pressure, equal temperature, an absence of conflicting currents, and therefore perfect ventilation. There is not the slightest probability of our introducing any such system at present in our dwellings, whatever may be suggested some day, but a little con- sideration of its real or apparent advantages may serve to render it clear that certain inevitable imperfection must attend any more localised arrangement for the entrance and escape of air.
The various contrivances which have been suggested maybe divided mostly into two classes — viz., those which provide for the entrance, and those which provide for the exit of air. They are mostly applicable to existing dwel- lings. Those which are not readily applicable it may be useful, for the sake of clearness, to consider apart from the others.
I . — Contrivances which provide for the entrance of fresh air.
No. i. Perforated zinc. — This useful material has been made by machinery for many years at a very low price. The perforations are of all sizes required for ordinary pur- poses, and are sometimes arranged to particular designs. See figures n to 18. Perforated zinc is used occasionally in place of a pane of glass in closets, larders, and other places, in the panel of a door, at the top of a window sash, or in the skirting-board of a room.
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No. 2. — Wire gauze, of various degrees of fineness, as figures 19 to 22, is used occasionally in place of perforated zinc.
No. 3. Air-bricks. — As figures 23 to 26. These have been usually made of iron, of the size of one or two bricks, and have been commonly put into an external wall to admit air to the basement or under the floors of a house. In such cases they preserve timbers and walls from damp, by the passage of air carrying off the moisture evaporated from the soil. " Air-bricks," if made of iron, should in all cases be coated with another metal, as by the process of galvanising, so as not to be liable to become rusted. They are now extensively made of brick or terra-cotta, as figures 27 and 28, with the perforations occasionally arranged so as to accord with the architectural features of a building.
No. 4. Sliding valves. — A few of these are shown in figures 29 to 31. They have been used in or over doors, or in walls, and frequently in conjunction with perforated zinc. Sometimes a frame of wood or metal is provided, with perforated zinc on one side, and a sliding valve on the other, so that air may be excluded or its admission regulated at pleasure. See fig. 63.
No. 5. Perforated glass. — This was first introduced under Lockhead's patent in 1848. See figures 32 and 33. It is frequently used in place of an ordinary sheet of glass, particularly over the doorway of a house. The patentee proposed that a shutter of glass, with a sliding valve to regulate the admission of air, as figs. 34 and 35, might be applied along with a sheet of perforated glass to the window of an apartment. Occasionally perforated glass has been made very thick, and put into a frame of iron for use in an external wall in place of the common air-brick.
No. 6. — Baillie's louvre ventilator, figs. 36 and 37, patented in 1837, is made of slips of glass fitted into a
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metal frame of the size of a window pane. It is usually fixed to the upper part of a window, and is provided with a simple mechanism for opening and regulating it. A similar ventilator was made many years ago by Mr. Moore and by Mr. Fairs.
No. 7. — Cooper's ventilator, figs. 38 and 39, is a modi- fication of fig. 34. It consists of a sheet of glass, having a few large perforations arranged within a circle, and a circular plate of glass having similar perforations, and made to turn upon the face of the other in such a manner that air might be excluded or its admission regulated at pleasure. It is fixed in the upper part of a window sash.
No. 8. — Sheringham's ventilator, shown in figs. 40 to 42, is fixed in an external wall near the ceiling. The opening, which allows a very free admission of air, may be graduated by means of a door, which can be opened more or less by a cord and pulley. An inclined plate of iron is said to deflect the current of air upwards, and thus prevent inconvenience from draughts. It is mostly used for passages, staircases, schoolrooms, &c. An air-brick, such as shown in fig. 32, is usually put outside the wall in communication with the ventilator.
No. 9. — Mr. William Cooke recommended that air should be admitted through wire gauze at the top of a window, as shown in figs. 43 and 44, and that the wire gauze should be so arranged in folds and fitted with joints, that when the window sash was opened the gauze became more or less extended at pleasure, and when the sash was closed the gauze became doubled against itself and pre- vented the admission of air. Mr. Stephen Flexen has adopted a similar system, but used perforated tin instead of wire gauze.
No. 10. — Figs 45 and 46 represent a somewhat neat looking arrangement, patented in 1849 by Mr. Obed. Blake. Mr. Blake proposed to make a few circular
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apertures either in the upper or lower part of a window sash, and to protect the apertures by a coarse description of wire gauze or perforated zinc on one side, and a finer description on the other. A sliding valve between the inner and outer perforations, moved by a handle, was arranged to close the openings when required.
No. ii. — Some ingenious arrangements have been introduced by Mr. Thomas Boyle. Figs. 47 and 48 represent a ventilator fixed in a window pane. A round hole of a few inches in diameter is made in the pane, and fitted with a piece of fine wire gauze. On the face of this gauze, and in the apartment, a disc of coloured or orna- mental glass is hung upon joints in such a manner that it can be pulled forward a short distance and allow air to pass through the gauze into the room, or it can be pressed against the wire gauze and exclude air. By another arrangement, Mr. Boyle introduces fresh air at the skirting board of a room. Fig. 48* represents a disc of metal, made to screw upon a circular frame fitted with wire gauze. This is fixed to the skirting or elsewhere, and a tube from it led to an air-brick in an external wall, permits the entrance of a certain quantity of air.
No. 12. — Mr. Charles Gammon, solicitor, patented in 1 86 1 an ingenious contrivance, which is readily adapted to a window sash. Figs. 49 to 52 represent the ventilator, which is in the form of a long narrow box, having a per- forated face of brass, a perforated back of zinc, and some perforated reticulations of zinc between them to break the force of the air, and arrest particles of dust. The face is divided into compartments, as shown in the fig., which are alternately perforated and plain. A plate similarly per- forated and plain is made to move over the surface of the perforated parts, by means of a pulley, to which a cord is attached, so as to regulate the amount of air admitted, or exclude air. The ventilator is usually fixed at the top of
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the sash, and has a cover hinged above the perforations, so that when the sash is pulled down the cover may be opened, and any dust that may have collected be either blown or brushed away.
NO> j^. — Another method, applicable in some cases, consists of a wooden frame, containing two or three louvre boards fixed above a doorway, as shown in figs. 53 and 54. The boards can be opened at pleasure for the entrance or escape of air by a similar machinery to that used with the louvre glass ventilator, fig. 36.
No. 14. — Ventilation by tubes against an external wall, commonly called " Tobin's System."
This consists of placing tubes made of wood or other material against an external wall, the lower ends being allowed to communicate with the outer air by means of a grating or air-brick, and the upper ends opening into the apartment at a height of 6 feet or more from the ground. The tubes should have an area internally of from 30 to 50 square inches, and might therefore measure 6 inches square, 4 by 8, 8 by 6, or any size we please of similar area. For a small room one tube might be sufficient. For large rooms and for public assembly rooms the number of tubes might be greatly increased. The principle con- sists, as every experienced person knows, in nothing more than this — that when the air of a room becomes of less pressure than the external air, whether by means of the expansion of air occasioned by warmth or the withdrawal of air occasioned by open fires, " sun-burners " for gas, &c., air will pass up the tubes and enter the chamber, without occasioning inconvenience to those present. It is simply a mode of admitting air without draught, and, as an alternative plan, may be well worthy of consideration. There are many modes of admitting air without draught, particularly by Sheringham's Ventilator; but as most of them admit of means for closing, there is the chance
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that they might be found to be closed when they ought to be open.
That a system of tubes to let in air over your head can be supposed to offer a solution of the whole question of ventilation is totally out of the question. In all assemblies and rooms much occupied there must be a real power of abstraction of vitiated air, and this Tobin's system does not offer at all. That it appears to have had a great success in some quarters appears to be entirely attributable to the fact that before the tubes were used there was no ventilation provided for except what proved to be unbearable, such as opening a window and letting in a sudden rush of cold air. One disadvan- tage of the tubes is that they might become receptacles for dirt, insects, &c., and require periodical cleaning.
II. — Contrivances which provide for the exit of air.
These are usually placed in communication with the chimney of the apartment.
No. i. — The Chabannes ventilating lamp for bedrooms, placed in a niche over the mantel-piece, with a channel leading from it to the chimney for the escape of air and the products of combustion, together with the opening from the room into the chimney, (figs. 6 and 7) have been already described in the notice of the Marquis's labors. See page 25.
No. 2. — The Chabannes chimney ventilator, shown in fig. 8, with a chain or a cord to regulate the opening. See page 25.
No. 3. — Dr. Arnott's self-regulating chimney venti- lator, figs. 9 and 10, contrived so that the door which closes the aperture should only open in obedience to a pressure of air from the room to the chimney, and on other occasions remain closed, has been already mentioned under the notice of the doctor's labors. See page 46.
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No. 4. — A simpler contrivance of chimney ventilator was suggested by the late Mr. Joseph Toynbee. Fig. 55 represents a metal frame having a front of perforated zinc and a curtain or valve of oiled silk suspended behind the zinc. The oiled silk opened spontaneously below as long as there was any pressure of air from the room to the chimney. On other occasions, when there could of course be no escape of air, it remained closed.
No. 5. — Mr. Thomas Boyle, whose arrangements for the admission of air have been already described, has also a chimney ventilator (fig. 56). Instead of using a single valve of metal or silk, Mr. Boyle divides the face of his ventilator into compartments, and behind each compart- ment he suspends a thin plate of mica,* which is suffi- ciently light to open in obedience to a slight preponderating pressure of air.
No. 6. — A contrivance for utilising chimney draught, but the true principle of which has been but little under- stood, in consequence partly of the curious title given to it, is the inverted syphon system of Dr. Chowne, which was patented in 1848. Dr. Chowne proposed to make a channel in the wall of a room from the ceiling to the fire- place, with an opening into the channel from the room just below the ceiling, and the other end of the channel so made to communicate with the chimney as to prevent the ascent of smoke in the channel. Dr. Chowne said of this system : " My invention consists of applying a principle which I have found to prevail in the atmosphere, of moving up the longer leg of a syphon and of entering and descending in the shorter leg, and this without the necessity for the application of heat to the longer leg of the syphon." If the doctor had been correct in his supposition, the whole question of ventilation would have
* Mica is used because very light, but will not close with the same accuracy as a heavier material.
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become effectually solved, for it would only have been necessary to construct a sufficient number of his "syphons" to ventilate any building whatever. All that Dr. Chowne was able to do was to utilize chimney draught in a fashion of his own. As long as there was an upward current in the chimney, and the opening above the fire-place was partly closed, air descended Dr. Chowne's channel by the force of gravity ; but, if Dr. Chowne had simply knocked a hole into the chimney below the ceiling, he would have found the air to pass away more readily from not having to undergo the preliminary process of des- cending. The system of Dr. Chowne was propounded long before by Mr. Tredgold, but has never been found to be of real practical value.
No. 7. — Systems of ventilating gas burners. See fig. 5 and figs. 57 to 60. The extensive introduction of coal gas for business and domestic purposes has led to the adoption of means for carrying off the products of com- bustion direct from the burner, so that they might not mix with the air used for respiration. Gas evolves in combustion a very large amount of carbonic acid ; it is sometimes deleterious from the presence of impurities arising from a want of proper attention in the process of manufacture, and it is often offensive from the defective state of gas burners. The entire removal of the noxious products should therefore be regarded as highly essential, but, though the matter has been to some extent urged for fifty years past, it is to this moment most strangely neglected. In some early attempts to avoid contamina- tion of the air by gas, the crude contrivance of a tube, with a trumpet mouth fixed over the burner and led into a chimney, gave a certain amount of relief, but the more elaborate attempt of the Marquis de Chabannes, to combine the removal of the products with the ventilation of a public chamber, as shown in fig. 5, was not by any
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means appreciated as it should have been ; for, after having been entirely forgotten, it has been revived of late years under the title of the " sun burner " system of ventilation. At the temporary chamber of the House of Commons, an excellent system of removing the in- jurious products from numerous gas burners, without any visible arrangement, was proposed by the late Professor Faraday, and carried into effect. In 1846, Mr. Rutter published a pamphlet,* in which he strongly recommended the system of ventilating gas lights whenever used in dwelling-houses, and suggested the use of a single light in a glass globe suspended from the centre of the ceiling, and channels from the ceiling to the chimney, for the escape of air from the room, as well as of the products of combustion. Figs. 57, 58 and 60 are taken from Mr. Rutter's pamphlet, from which it will appear that a system identical in all its main essentials, and largely advertised, a few years since was made to bear the name of another. An indispensable precaution is that the channel for the escape of air from the room should be of ample size, or it would be quite ineffectual. The system, as far as the use of gas is concerned, should need no comment. Wherever gas is burnt there should be such a system, but, so much trouble and expense are involved in applying it to existing build- ings, that it is highly necessary proper provision should be made while a house is in course of construction.
It has been occasionally attempted to ventilate a room from the centre of the ceiling, by carrying a tube from it into the chimney, the ornamental plaster work called " a rose " being provided with apertures or suspended a short distance below the ceiling, so that air might escape above it into the ventilating tube. This has been quite irre-
* " Practical Observations on the Ventilation of Gas Lights." By J. O. N. Rutter, F.R.A.S. London : John W. Parker, 1846.
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spective of the use of gas. Fig. 64 represents a sketch given by Mr. Tredgold, but slightly modified. There is an apparent advantage in the system from its dispensing with the sight of a chimney ventilator, but it is not equally effectual. The air has to travel horizontally in the channel before it enters the chimney, and whatever some persons may consider air ought to do under such circumstances, those who have a little familiarity with its movements are aware that a current of air would enter the chimney less readily than if the communication were more direct. When assisted by the powerfully-heated products from a gas burner, the ventilation may be sufficient, but seldom so on other occasions. Another difficulty is that it cannot always be very practicable to provide a channel of sufficient area for effective ventilation. Very small tubes are good for nothing. The channel should seldom have a less sectional area than twenty-four inches ; some- times double the quantity or more.
Of the preceding propositions for the admission and exit of air, the same general principles run through nearly all, viz., that fresh air should be introduced at a high level in a room, and that the chimney should be utilized as far as possible for the escape of air. There have not been wanting many persons who have seriously questioned the propriety of introducing fresh air at the upper part of a room. It is usual for them to contend that the warm vitiated air from the lungs ascends and contaminates the fresh air. Prac- tice has, nevertheless, almost invariably followed a course in discordance with such theory, and not without good reason. When cold air is introduced below, the sensation to the feet is very disagreeable, but, when carefully intro- duced above, it increases in temperature by contact with warmer air, and mixes with the general body of air in the room without occasioning the slightest inconvenience. These remarks, it must be borne in mind, refer only to
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the supply of air for domestic and other ordinary purposes, and do not apply to public rooms or buildings where different conditions demand different treatment.
Whenever there are arrangements for warming the air before it enters the room, the air is of course admitted near to or at the floor. Dr. Reid, it has been seen, had a perforated floor, an open carpet, and his warming appa- ratus below. For domestic purposes, it is common to use hot-water pipes fixed behind the skirting-board, with gratings to admit air from an external source into the main air channel containing the pipes, and thence through other gratings, or slips of perforated zinc, into the room. Others have used a metal grate, as figs. 68 and 69, with a warm air chamber behind, which has been placed by means of an air channel in communication with an ex- ternal wall, and by means of certain apertures on the front surface of the grate, in communication with the room. A certain amount of fresh air enters after becoming warm by contact with the back part of the grate.
With respect to the notion that fresh air, when intro- duced above, is more liable to contamination before it is inhaled than when introduced below, this may appear to have some plausibility, but a little consideration may render it doubtful whether it has much force. There is no doubt that air escaping from the body is warm and charged with that which is unfit to return to the lungs, and it is also true that warm air ascends ; but it is equally open to observation that the air propelled from the mouth takes a forward movement for a short distance, that it rises a little, and that the further motion of the particles is lost altogether. It would take more delicate instru- ments than have ever been devised to trace any continuous current of air occasioned by the process of breathing or by the heat of the body. What we know very well is, that vitiated air becomes instantly distributed, and is found
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very generally to pervade an apartment when present in sufficient quantity to be perceptible, notwithstanding any theory that may be formed on the subject.
The various contrivances at present described for ad- mitting air differ in value according as they distribute the air over an extended surface, according as they provide means for checking the impetus of the air, and according as the quantity of air admitted is easily regulated. Per- forated zinc, wire gauze, perforated glass, air bricks and sliding valves, figs, n to 33, are all useful in certain cases, particularly when they form part of some special contrivance. Mr. Lockhead's ventilator, figs. 34 and 35, appears to be a very good one, though, perhaps, not readily applicable to large panes. Baillie's or Moore's louvre ventilator has been very largely used, but draughts from it cannot always be avoided. Mr. Cooper's ventilator, fig, 38, and Mr. Sheringham's ventilator, figs. 40 to 42, appear to be clearly open to the same objection, though the latter has been used for a long number of years, and on the whole very satisfactorily. Mr. Cook's or Mr. Stephen Flexen's plan, figs. 43 and 44, offers a considerable area, and its success would depend probably on the joints being always in proper working order. Mr. Obed. Blake's plan, figs. 45 and 46, satisfactorily fulfils several conditions. The air is distributed, draughts are prevented by the double gauze, and the means of regulation are simple, but care should be taken to remove the pieces of gauzes occasionally which face the room for the purpose of removing dust. Mr. Boyle's arrangement for putting a ventilator in a window pane, figs. 47 and 48, has some good points. Within a chamber, the disc of glass to cover the wire gauze is by no means unsightly, but the appearance of the bare disc of gauze without would often be objectionable. His plan of introducing fresh air at the skirting by fig. 48 is unobjectionable in winter, provided
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the air is warmed. Mr. Gammon's ventilator, figs. 49 to 52, is carefully constructed to admit air and prevent draught, and, as it is readily applicable, is undoubtedly a useful little contrivance. The last plan, shown in figs. 53 and 54, that of providing louvre boards above a door- way, is capable of admitting more air than the other con- trivances, though, under most circumstances, it would act as a means of interchange, air both passing in and out between the louvre boards. It is not very sightly, and appears to be most applicable for smoking-rooms, work- rooms, and other places where greater provision for a change of air is required than in an ordinary apartment.
It will be inferred from the preceding observations, that the contrivances of Messrs. Lockhead, Cooke, Flexen, Blake, Boyle and Gammon, are preferable to those of Messrs. Baillie, Moore, Cooper and Sheringham, from their greater power of avoiding draught, but it must not be supposed that the latter are objectionable in halls, pas- sages, and many lofty rooms, where cold air may be ad- mitted with much greater freedom than in ordinary bed rooms and sitting rooms, or that wherever double windows are used, the ventilators of Baillie, Moore and Cooper, may not answer their purpose perfectly well. In this latter case, the ventilator may be fixed in the external sash, and air admitted into the room by slightly opening the inner sash at the top. Of the other description of ventilators Mr. Gammon's is least perceptible when fixed, but it does not disperse the air so much as the contrivances of Cooke, Flexen and Blake. If applied to every window, it may however be sufficient for all practical purposes, and there appears to be no reason why it should not be made of any length that is desired. Irrespective of these various con- trivances, however, it is easy for any one with a little in- genuity to contrive, with the aid of perforated zinc or glass, wire gauze, air gratings and sliding valves, any arrange-
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75
ment that may suit his own fancy, and if he can be trusted not to rush off to a patent agent to get him a patent, he may have served himself without losing his money.
For the escape of air from the room the chimney is nearly always available, and it would be more frequently so than it is if the supply of fresh air from the doors, walls, or windows were in all cases sufficient. The upward current in a chimney is of course greatly inter- fered with if a rarefied atmosphere is allowed to exist below. When a fire is actually burning, the chimney answers the purpose of ventilation most powerfully, and occasionally excessively, so that a contraction of the fire- place becomes indispensable for the purpose of warmth. It is exactly this contraction of the fire-place which makes it possible to utilize the chimney draught above. It is only necessary to break a hole into the chimney anywhere below the ceiling for an additional amount of air to pass away, and that without occasioning personal inconvenience from any current. A contrivance of some kind is invariably provided to close the aperture when there is no draught, or when there is a down current. In the Marquis de Chabannes' chimney ventilator, fig. 8, there was a door with a chain, while Dr. Arnott, Mr. Toynbee and Mr. Boyle, (figs. 9, 10, 55 and 56) have had self-acting doors. Much disappointment has arisen to many persons from their being unfamiliar with the essential conditions for a chimney ventilator to be suc- cessful, and in some quarters its utility has been too hastily questioned. It is worse than useless for one to be put into a chimney when the fire-place is large and open. As long as a body of air, filling the whole chim- ney, passes freely through it from the fire-place, none will pass through the ventilator, and smoke may very possibly find its way through the ventilator into the room, but if the fire-place be contracted the two openings will
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do quite as well as the one did before. A chimney venti- lator is generally useless in a very small chimney, for if the latter is only large enough to allow of the passage of air from the fire-place, there can be no escape above. It is also useless when there is a down current in a chimney, or when there are reverse currents, and of feeble use when there is a very gentle current It is only unques- tionably useful on those occasions when the air in the chimney is more rarefied than the air without, and the opening into the chimney is partly closed below. It is most useful when a fire is most active, and this is exactly the time when it is generally least wanted, but it must be remembered that the chimney ventilator has the advan- tage of turning the chimney to the fullest account of which it is readily susceptible, and that in existing build- ings, the reasonable course is, to make the best of any resource already at command.
Objection has often been made by architects and others to the liability of sooty particles being blown into the room, and to the flapping noise made by the door of the ventilator in gusty weather. If soot is liable to be blown through the ventilator, it appears probable that it may also be blown down into the fire-place. The ventilator in this case should not be blamed, but the malconstruction of the building, which must allow a strong current of air to descend the chimney, or the chamber itself may be insufficiently supplied with air, and therefore frequently occasion down-draught. With a sufficient pressure of air below, and a simple protection above, down-draught, whether from wind or otherwise, could hardly be known. The same precautions would doubtless suffice to prevent the flapping noise of the door. Upon this last point, however, it may appear that the little mica valves used by Mr. Boyle, fig. 56, would be less likely to occasion the slightest annoyance than the single metallic flap of Dr. Arnott, and be therefore preferred.
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It was unfortunately propounded by Dr. Arnott, when he urged the general use of his modification of the Mar- quis de Chabannes' ventilator, that a broad distinction was to be drawn between the air below and that above the chimney mouth, — that the former was pure, while the latter became extensively charged with unwholesome emanations, which could only be removed by an aperture being made in the chimney below the ceiling. This theory supposes that the whole body of air in a room below a certain level is in a state of motion, and passes away sooner or later by the chimney, to be replaced by fresh air, while the air above that level is in a state of comparative stagnation. There do not appear to be strong grounds for believing that this theory accords with facts. There is no doubt that a considerable quan- tity of air passes away by a chimney, and chiefly when a fire is burning, but where the air comes from is not so readily ascertained. Air enters the room wherever it can, and there is often a current over the floor, and a current up the chimney. What is not so well known is, that there is a constant ascent of air in the room in front of the fire-place, so that much of the air which arrives there becomes expanded and circulates in the room. Apparently the only safe conclusion that we can come to, from many experiments which have been made, is that the whole body of air in a room is in motion, that certain currents are to be occasionally traced, and that sooner or later, by the powerful action of a fire, the air of a room becomes entirely changed. As the same thing happens, but to a less extent, as long as there is an upward current in a chimney, we need not perhaps go so far as to apprehend that our children will begin to ail when their heads rise above the fire-place, if we do not give them the benefit of a chimney ventilator.
If a ventilator to admit air in moderate quantity be
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provided to every window, if an open fire-place be used, and the chimney be otherwise turned to account ; and if gas be only used along with effective means for removing the products of combustion, there can hardly be reason- able grounds for supposing that the chambers of our dwellings will not be as well ventilated as existing cir- cumstances will readily permit. A slight addition might however be made in the shape of such an article as shown in fig. 63, which could be fixed below the cornice over a doorway, and be used instead of a window venti- lator in very cold weather, so as to allow the exit of air or a gentle interchange according to the existing circumstances of the apartment.
We will now proceed to a consideration of the special application of the principle of good ventilation to the different portions of a dwelling. The question so far as it is connected with the case of open fires in winter and the prevention of smoke is considered in the next chapter.
Ventilation of Basements.
It is beyond the scope of this volume to enter fully upon such questions as the avoidance of damp, the re- moval of refuse, the burning of vegetable and animal matter which may be liable to decompose, the trapping and flushing of drains, and the use or abuse of sink traps, but considering the obscurity in which many basements of great houses are suffered to exist, we cannot forbear from quoting a passage from Captain Douglas Galton's recent book on the subject of light :
" A dark house is an unhealthy house, an ill-aired house, and a dirty house ; therefore light should penetrate to every part. There should be no dark staircases, corridors, corners or closets. Direct light by means of windows easily opened to the outer air is required to ensure the frequent renewal of the air."*
* Healthy Dwellings, page 158.
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When light is freely admitted to a basement, defects may easily be perceived, otherwise they may remain for years undetected. The admission of fresh air to a base- ment is very essential ; it is required for the purpose of maintaining dryness and to supply the air drawn off by kitchen and other fires. Sheringham's ventilator, fig. 40 will answer the purpose, or the wooden channels known as Tobin's. In many cases, however, these channels can be best used in basements when inverted, the fresh air entering the channels from above and passing into the house from below, say a foot or two above the floor line. By this means the fresh air may be taken from a higher level than the ground line, and be admitted without draught.
Ventilation of Kitchens.
This is a very essential matter, one of the great incon- veniences of modern houses arising from the use of the kitchener, which when not properly ventilated allows the fumes of cooking, the smell of burnt animal or vegetable matter to pass up the stairs into the body of the house. It may be considered to be a point which hardly requires demonstration that a sufficient supply of fresh air should enter the kitchen to replace what passes away by the flues. This may be obtained by air from the adjoining passages, by Sheringham's or window ventilators, or by wooden channels against the walls, as already described. It is extremely necessary that the dampers to the flues should not be opened more than absolutely necessary, both for the purpose of checking a waste of fuel and an unnecessary escape of air. As gas hot plates are often used it is well to state that they should always be pro- vided with a canopy with a flue from it leading into the chimney, protected at top so as to prevent the falling of soot, down the flue. The canopy and flue allow the noxious fumes to pass securely away.
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For the ventilation of the hot plate of the kitchener a very successful contrivance of the author has been the ventilating funnel shown in fig. 61, which is fixed over the roof of the kitchener and is left permanently open, the draught which carries off the heat, &c., not interfering with the action of the flues. A simple covering pro- vided at top prevents the falling of soot on the hot plate. This funnel can be fixed in its place or removed when necessary by means of two turnbuckles (screws which can be moved by the fingers) which attach it to a fixed metal frame, removal being only necessary when the chimney itself has to be swept.
An important point in connection with kitcheners is the absolute necessity of using the roasting dish with water trough, which prevents the burning of fat inside the roasting oven, also the use of the simple ventilating arrangement introduced by Count Rumford, which allows a current of fresh warm air to pass incessantly through the oven. It is by these two contrivances that the dis- agreeable flavour of baked meat is entirely avoided.
A further point connected with kitchens will be alluded to further on in speaking of the upper floor, where means require to be used to prevent the passage of air from the kitchen department. The necessity of lime-whiting the walls, having clean paint and floors, and of exter- minating vermin needs not to be insisted upon.
Ventilation of the Ground Floor, generally consisting of Hall, Dining Room, Library, &c.
Admission of air to the hall and at different windows on the landings or stairs must be considered to be indis- pensable. A fire is often burning in the hall which, unless carefully regulated, may send many thousand cubic feet of air per hour up the chimney. The air must be provided from somewhere ; if it cannot enter the house by
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the hall door or other suitable means, air will pass up the chimney from the house itself, exhausting it to the disad- vantage of other fireplaces ; or it will enter from the kitchen department, whether on the same floor or below, and bring with it a smell of cooking. Possibly the chimney is found to smoke which generally indicates that there is not a due supply of air to replace what has passed away. And we must bear in mind that it is generally from the hall, landing windows, &c., that a large body of the air enters our rooms and passes up our chimneys, and that if it does so, it must be in some manner replaced. This may be done by Sheringham's ventilator, ventilators in the windows or ventilating tubes.
Ventilation of Dining Rooms.
The admission of a sufficient supply of fresh air to a dining room without draught is very essential, as such a room becomes rapidly contaminated by the breath of many persons, by mastication, by the heat of the viands, and by the means used for lighting. Sheringham's ven- tilators or Tobin's tubes are very beneficial.
Ventilation of the Library.
This is a more simple business as it is seldom occupied by many persons. A simple ventilator which will allow fresh air to enter imperceptibly is all that is generally required.
Ventilation of Drawing Rooms.
These sometimes present great difficulty in consequence of their being occupied occasionally by many persons and much light being then used. If the body of the house be sufficiently supplied with fresh air, drawing rooms will receive a better supply than they now do, and they may receive a still better supply by the means indicated for
G
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other rooms. The gas lights may be ventilated by the means already described and a supply of air may be given to each fireplace by the method described in the next chapter.
If these means are insufficient the only sensible alter- native is thatwe should avoid entertainingalarger company than can find air fit for respiration, say three persons to a thousand cubic feet of air. Drawing rooms are not provided with special means for extracting air like Theatres, Music Halls, the Houses of Parliament, &c. It is therefore worthy of consideration whether public rooms specially ventilated might not be utilized or con- structed for the private entertainment of a large company. A great difficulty, which often exists in a suite of three drawing rooms, is that while two of the fires burn very well the third is an inveterate smoky one. This is due to the cause which the writer has often pointed out, viz., that the rooms are not sufficiently supplied with air to replace what passes away, so that the deficiency has to be made up by air rushing down the troublesome chimney and a steady upward current is impossible. The only sensible remedy is to reduce as much as possible the air which does pass away by means of proper registers and to supply the rooms sufficiently with fresh warm air, admitted without any draught.
Ventilation of Bed Rooms.
For a bed room to be properly ventilated it should give no indication to the sense of having been occupied a very short time after a person has slept in it. This can be attained by admitting air at the door, window or walls. By means of the door we may admit air or allow an interchange. A door-chain may be used which will allow of a door being opened three or four inches without any probability of disturbance. Some persons have used in
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the case of travelling a wedge of wood to be pushed un- derneath the door which would allow of a bed room door being secured to such an extent that it could not be opened more than the regulated space allowed, say an inch or so without their becoming alarmed.
Another simple plan, applicable to our own dwellings, is to allow air to come in between the upper and lower window sash by raising the lower sash and filling the space below it by a piece of wood, measuring in length the width of the window sash, in depth, one, two or three inches, and in thickness exactly the thickness of the window sash, probably about one and a half inches. This fills up the space below the lower sash so that air can only enter vertically, generally without draught at the open part between the upper and lower sash. Captain Galton has suggested making a slit vertically at the bottom of the upper or at the top of the lower sash. This answers the same purpose, and it enables the window to be fastened.
Perhaps the principal source of contamination in a bed room is the emanation from the liquid matter which the body rejects. Glazed earthen covers might be used, or some other contrivance which requires the authority of a leading physician to suggest and introduce.
When a lamp or a gas-light is used in a bed room, the simple ventilating lamp of the Marquis de Chabannes, shown in fig. 6, might be used with a tube from it to carry off the products into the chimney.
Ventilation of Attics.
This is not a very difficult matter, the attic floor being frequently the most healthy in a house. It is far from the basement of a house, far from drains and from impurities on or near the surface of the ground. Con- taminated air from below seldom reaches the attics. There
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is often a skylight of some sort by which light and air are admitted. The evils to which attics are exposed are generally of a different character to those which are en- countered in lower stories. These evils are due entirely to the deficiency in the necessary supply of air to the lower stories, so that there is a constant tendency of air to pass down from the attic floor to the floors below and thus remedy to some extent the evils existing there.
To replace the air which descends from the attic floor, fresh air comes in by openings in the skylight, if one exists, air enters by the windows and air descends the chimneys, rendering it difficult or impossible for fires to be used. There is thus ample ventilation and possibly too much of it. It gives to the upper floor a sense of coldness, to which the fireplaces offer no effectual remedy. The only way to render the attic floor as comfortable as the lower floors is by admitting sufficient air to the lower floors for respiration and to replace what passes away by the chimneys. If this be duly attended to, the attic floor may be as comfortable as any in the house.
One useful suggestion of Captain Galton is to admit air in the skylight by inverted louvres, which divert the air upwards before descending and prevent a sudden descent of cold air. The use of the ventilating slip at each window is highly to be commended.
Ventilation of Cupboards and Closets.
This may generally be effected by means of a slit cut out of the bottom of the door and a slit or a few holes being cut at top.
Ventilation of Water Closets.
This is a far more important matter than many would readily or willingly conceive. Modern ideas of comfort and refinement require that they should be comprised
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within the interior of our dwellings, but a sufficient pro- vision for maintaining a purity of air is scarcely ever to be found. When fires are in use and the air of the house becomes reduced in pressure, the window of the w. c. is one medium by which air passes into the house. Air may even ascend the soil pipe and enter the house. It is not easy to suggest a remedy, as it is a subject that can only be fully dealt with when the house is constructed. We may say that the chamber of accom- modation should always be against an external wall and if possible at the end of a passage, with an intervening door and window by which window fresh air could be insensibly admitted. In the chamber itself some means of ad- mitting fresh air left permanently open must be provided. A most useful provision would be a wooden trunk or channel protected by louvres, which could be carried as high as convenient against the external wall and allow a gentle interchange of air. The ventilation of the soil pipe has been alluded to elsewhere.
Ventilation of Rooms without Fireplaces.
This can be done at the window or the wall. Such rooms may often be greatly relieved by a somewhat large tube (say about nine by four inches) being led from the partition below the ceiling into the chimney of an ad- joining room. Such a tube would look like a beam, and though not very elegant, is better to be borne with, than that any persons should be required to subject themselves to unrefreshing sleep amidst the stagnant air of an entirely closed chamber. It requires no great amount of ingenuity to make it as ornamental as useful.
Public concern with respect to ventilation has led some persons to enquire what special arrangements could be made in the original construction of dwellings, which would provide more effectually for the entrance and escape
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of air than any adaptations to existing buildings, and there have accordingly been several suggestions, which have been applied occasionally within a few years. The suggestions for the escape of air generally involve the construction of perpendicular ventilating shafts or flues in the walls of the house, by which air can pass away from a room inde- pendently of the chimney, the object being to dispense with the use of chimney ventilators and the incon- venience which has been sometimes found, necessarily or not, to result from them. The simplest description of shaft is a mere channel formed in brickwork in a position contiguous to the chimney, so that it may receive some heat from the intervening brickwork. An open grating fixed below the ceiling places it in communication with the apartment, and where it terminates above the roof, some simple provision is used to prevent the descent of wind or rain. It may answer its purpose very fairly, pro- vided the means for admitting fresh air below furnish a larger area than the apertures into the chimney and into the ventilating shaft, but there is, of course, never so powerful an upward current as may be sometimes obtained through the chimney ventilator by the use of a fire.
An improvement on the common ventilating shaft was patented a few years since by Mr. D. O. Boyd, by which more of the heat of the chimney becomes utilized for ven- tilating purposes. Mr. Boyd's plan is to construct the sides of each chimney of thin iron plates instead of brick- work, as shown in figs. 70 and 71. The iron plate alone divides the chimney from the ventilating shaft. A shaft may be formed on each side of a chimney, and between two chimneys, according to circumstances. Metal being a rapid conductor of heat, the temperature of the air within the shaft is increased to a greater extent than if there were the interposition of brickwork, so that an upward current is more easily created or accelerated when
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there is a fire burning. An open grating below the ceiling allows the escape of air as in the last case.
Another suggestion has been the combination of chim- ney and ventilating flues proposed by Messrs. Doulton and Co. Their method is for chimneys to be constructed of glazed earthenware pipes made in lengths, as shown in figs. 72 and 73. Distinct from the smoke flue are two ventilating flues, one on each side, which are placed in communication with the room below the ceiling. The contrivance appears to provide for economy in construc- tion, but with respect to utility, it is probably a little more serviceable than the ventilating shaft formed in brickwork, and somewhat less so than the better-heated ventilating flues of Mr. Boyd.
A more elaborate arrangement, and one calculated to command attention in consequence of the quarter whence it proceeded, is the system of ventilation and smoke flues, described in the Board of Health Report on the Warming and Ventilation of Dwellings. Plate A in the Report, represents the section of a house having the whole of the fire-places arranged back to back against a partition wall, and a single smoke flue to receive the smoke from every fire-place from the kitchen and scullery in the base- ment to the bed rooms on the top story. The smoke flue is supposed to be formed of clay pipes about ten inches in diameter, and to be connected with each fire-place by a short branch tube, which is to be carefully closed when not in use. Around the smoke flue is shown a ventilating channel reaching also from the basement to the roof, having no communication of course with the smoke flue, but terminating a short distance below it above the roof, and being made to communicate with each apartment by means of suitable apertures below each ceiling. The con- siderable amount of heat communicated to the ventilating channel by the constant ascent of heated air from a
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kitchen fire, as well as from the other fire-places when in use, is supposed to command an upward current of suffi- cient capacity and power to withdraw air from every chamber. A provision is made for sweeping the chimney from the basement, and the comprehensive arrangement is completed by the suggestion of the system of intro- ducing to every room, in winter, a supply of fresh air in close proximity to the fire.
The commissioners rightly state that the success of this system " cannot be vouched for," but they consider it " entitled to the attention of architects and builders as an experiment worthy of trial." If no response has hitherto been made to the appeal, it is possibly because the com- missioners have not shown themselves to be even aware of the difficulties that would have to be encountered in departing from existing practice. Such difficulties have been encountered invariably when it has been attempted to use even a chimney of the present large dimensions (14 by 9) with more than one fire-place. It is obvious enough that if a single chimney could be used for several fire-places, by simply connecting chimney and fire-places together, our builders would long since have availed them- selves of so economical a method. Nevertheless, it is not impossible for two or more fire-places to be used with a single chimney, provided certain precautions are taken, which appear simple enough when once understood, and the necessity of which would have been evident, if the subject had only been experimented upon and duly considered.
It may first be remarked, that a radical defect of the arrangement consists in the suggestion that so many fire- places could be used with a single small chimney. This is so far from being the fact, that a chimney of such dia- meter as ten inches, would barely suffice for the kitchen alone. Many unfortunate builders have got themselves
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into trouble, and many householders have suffered con siderable annoyance in consequence of the kitchen chimney being built too small. If the common open range is used, the current of air through the small chimney is not sufficient to take away all the smoke, and an oppressive atmosphere is the consequence. Perhaps the chimney is barely suffi- cient in size, and then the sweep's attendance is constantly required to make the best of the restricted channel. Perhaps the open range is abandoned and the close range substituted, which, being more of the nature of a furnace, has a better chance. But though the close range may be used with a smaller chimney than an open range, due pro- vision must be made for the escape of the currents of warm air, laden with gases resulting from combustion which seek to escape by the flues. It would be uninterest- ing to enter into details, but it is safe to assert, that our cooking arrangements, as at present constituted, could scarcely ever be carried on with a chimney of less than ten inches in diameter, and frequently require a much larger capacity.
Due provision being made for the escape of smoke from the kitchen fire, the requirements of the other apartments require careful consideration. It is utterly useless to make an opening into a channel that is already filled with a current of air, and expect that air will flow into the channel from the new source. The unreasonable expec- tation may possibly be rewarded by the channel dis- charging a portion of its contents at the aperture. It is therefore absolutely indispensable that a main channel should be of no less capacity than all the small channels put together. To settle the dimensions of the smaller channels great care is necessary. The current of air charged with smoke and other offensive products, must pass readily away or there will be great annoyance. A tube three or four inches in diameter to remove smoke
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from a fire-place having a much larger area would be quite ineffectual. There might possibly be a passage of air through the tube, and that is all we can say. The successful and proper arrangement appears to be a vertical channel of the whole width of the fire behind, made narrow from front to back, and with an enlarged opening where the tube is made to communicate with the fire-place. This form enables the channel to be restricted to the smallest dimensions compatible with the effectual escape of smoke.
The effect of the minor channel being made to enter the main channel vertically is, that there is but little like- lihood of one current checking the impetus of another, and that therefore the main channel may be reduced to the smallest dimensions consistent with the various de- mands made upon it. What the dimensions of the main channel should be, must of course differ in different cases. Anything like ten inches diameter would, it is clear, be totally out of the question, and the fact of such a size having been deferentially suggested for ten fire-places by men so undoubtedly worthy of respect for their scientific labors as the commissioners, is but an instance of what very erroneous notions may be formed upon any subject in the absence of careful observation or experiment. If we take half the number of fire-places suggested, i. e.y one tier only, or five in a house of four stories above the basement, the main chimney could hardly have a less capacity in clear area than two hundred and sixteen square inches, and would therefore be about twenty-four inches by nine.
If the dimensions of the main and the minor smoke channels be carefully attended to, as well as the mode of communication, and if the various chambers be properly supplied with air for the support of combustion, there is no reason why one smoke chimney, with various branches, may not supersede the distinct chimney now used to
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each fire-place, and one or two architectural terminations at the roof may take the place of a row of chimney-pots. The sweep's labors may then, as suggested by the com- missioners, be incurred at the basement of the house instead of in the separate chambers.
Those who believe contrary to common-place experience, that small smoke channels may be made to prove quite efficacious for open fire-places, would do well to profit by some of the experience which has been gained at the whole range of buildings comprising the Houses of Parliament, respecting both smoke and ventilating channels, or they may, if of mechanical turn, devise a method by which the gaseous products of a fire may be collected into a small compass, and shot up the chimney.
If a main smoke channel may be made effectual for several fire-places, there is no reason why a main venti- lating channel should not be made effectual for several rooms. In a previous volume the author has illus- trated the system suggested by the commissioners, but greatly modified, showing the smoke flue contained within a large ventilating channel, and various openings from the rooms into the channel. It is not perhaps so necessary that there should be a short vertical com- munication from each room, as in the case of the smoke flue, as the passage of air is more gentle, but it is ab- solutely necessary that the main channel be of sufficient capacity for its different requirements, and that the aper- tures communicating with each room do not exceed in area such a proportion of the ventilating flue as can be alloted to the use of such room. It is also essential for the prevention of return currents, that the amount of fresh air admitted by various means to the room, be quite equal to that which it is desired should escape both by smoke and ventilating channels. Instead of making the communication with the ventilating channel by means of a grating opening
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immediately into it, a perforated strip of metal might communicate with the ventilating channel just over the centre of the mantel-piece, and similar perforated strips might also enter it just below the cornice. Any one familiar with design or decoration may easily arrange that such apertures may form part of any general orna- mental features.
In the commissioners' section two different ranges of fire-places are shown, put back to back, and opening into the same chimney, and it is suggested in their report that in the case of such a system being found to occasion in- convenience from the smoke of one fire-place being liable to escape at another fire-place, that the evil would be avoided by the smoke channel being divided in the middle, so that the fire-places on one side might not communicate with those on the other, or that two smoke flues might be arranged in one ventilating channel, one of the smoke flues to be used for one set of fire-places, and the other smoke flue for the other set. These pro- positions involve an entire change in constructional arrangements with respect to the position of fire-places, for the purpose of combining the smoke and ventilating flues for an entire dwelling. Dr. Reid suggested the possibility of such a thing being effected, but he was probably too much absorbed in other matters to elabo- rate his notions. There might possibly be some advantage arising from the suggested alteration, but not in the use of a single smoke or a single ventilating flue. These it would be necessary to divide. A certain benefit might be gained by the heated air from the kitchen fire being made to contribute warmth in some way to both ventilating flues, and there might be some advantage in providing channels for the escape of air in positions opposite to the windows instead of at right angles with the front and back wall, but the disadvantages would be enormous. Fire-
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places would often necessarily be found in close proximity to the doorway, and there could be no communication between front and back rooms by means of folding doors. That on certain occasions fire-places might readily be arranged back to back may be quite clear, but this appears to be far from being the case in the great majority of dwellings.
Instead of a ventilating channel in connection with the smoke-flue, a system of providing for the escape of air from the partition-wall opposite the windows might be used sometimes with advantage. Perpendicular ventila- ting channels some few inches broad, but very shallow, might allow the escape of air just below the cornice. The partition being generally warm, from its position between rooms in which fires are used, would insure an upward current, provided the supply of fresh air from the usual sources was sufficient. There might also be such channels provided in the hall, or about the staircases or passages of a house. The water-closets should in all cases be pro- vided with a ventilating flue, in which a jet of gas within reach of the hand might be used in dark hours.
Of arrangements for the admission of air which are rather applicable to new than to existing dwellings, there is the combined ventilating and smoke-flue of Mr. George Jennings, the sanitary engineer, which is shown in fig. 74. Instead of using the four hollow channels shown at opposite points of the smoke-flue for the escape of air in the same way as Messrs. Henry Doulton and Co. by their scheme (figs. 72, 73), Mr. Jennings endeavours to apply the sugges- tion contained in Count Rumford's book, and put into prac- tice at the House of Commons by Dr. Reid, viz., that of sup- plying fresh air to a room from a high level. He therefore makes his flues descending flues, in which the air becomes warm by contact with the earthen chimney before it enters a room. Open gratings and regulators are provided to con-
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trol the admission of air. The scheme appears very pretty as illustrating what can be done, but it is open to question whether its advantages preponderate over or are equal to the advantages of others. The essential conditions for its success are, that other means for admitting air should be carefully closed up, and that the air in the room should become rarefied by the action of a fire. Air then, whether warm or not, descends the ventilating flues by the force of gravity, and enters the rooms. As it is natural for warm air to ascend, there appears to be a loss of power incurred by its being made to descend. Such loss it might be worth while to incur if the air were unquestionably purer. That it is necessarily more pure may appear doubtful. Smoke and other offensive products from our chimneys are discharged at a high level, and necessarily contiguous to the ventilating flue, and though many might feel more motion in the atmosphere upon the roof of a house than at a low level, and a certain benefit therefrom, that is not to say that the same air, without perceptible motion, is more wholesome than other air. At a low level we are occasionally exposed to offensive emanations, but, as we must of necessity breathe air from a lower level than the roof of a house whenever we are abroad and whenever we open our windows, it may appear that the proper remedy is a compulsory avoidance of certain nuisances.
Another system of admitting air is by a perforated cornice, but the title may mislead, as the cornice is only used to cover and conceal some other appliance for the admission of air. Sometimes the cornice has been made of wood, with large perforations. One or two air-bricks fixed in an external wall, with a regulating valve, have allowed air to enter a hollow space between the cornice and the wall, and thence by a few apertures into the room, all the remaining apertures serving only for orna- ment. Fig. 65 represents a ventilator for admitting air at a
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cornice, which was used with much success by the commis- sioners appointed for improving the sanitary condition of barracks and hospitals, and recommended in their report.* The upper portion is of perforated zinc, the lower portion of wood, and is fixed, as shown in fig. 66, with an air-brick or grating without, a regulator, a provision for dispersing the air right and left, and the perforated zinc so placed that the air may ascend to the ceiling on its entrance. The contrivance may appear crude for dwelling-houses, though perhaps perfectly applicable, with a little cautious treatment ; but it may be possible to suggest for ordi- nary purposes simple and unobjectionable methods of introducing air above the windows, which might be pre- ferable in some respects to this and to other methods already described.
Fig. 87 represents in section the upper portion of a window-opening so arranged as to admit air quite in- dependently of the window sash. Air from without passes through the apertures of fig. 90, into an open space of about six inches square, and through pieces of gauze or zinc, as shown in fig. 89, into the room. A flap of very fine perforated zinc or gauze, shown in fig. 88, and as fixed in fig. 87, might be so arranged that when pulled forward it would greatly reduce the amount of air admitted without excluding it, and be pulled back again to admit the maximum of air ; certain facilities required to be provided for the removal of dust. Fig. 91 represents a similar system, but instead of the perforated apertures of fig. 89, and the finely peforated flap, fig. 88, a cylinder might be used as fig. 92, of about four inches in diameter, formed of strips of gauze or zinc soldered or wired together, and so suspended and made to revolve that more or less air would be admitted, according as a finer or coarser descrip-
* Issued in 1861.
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tion of gauze or zinc faced the room. The appearance from within would be as shown in fig. 92*. The arrange- ment would require a provision to be carefully made for the easy removal of dust.
If arrangements be adopted for admitting air impercep- tibly at our windows, and warm in winter, at positions near the floor, and if air be removed by ventilating channels and the open fire-place, we shall have done much that is readily within our power to maintain both a comfortable and wholesome atmosphere in dwelling-houses. Such atmo- sphere will be much more pleasant and invigorating than the rarefied air which many have often to breathe, which some get accustomed to, to such an extent, that the cold external air is offensive and hurtful to them, while others, more habituated to a dense atmosphere, either within or without, find the rarefied air to injuriously affect the nervous system and the agreeable and systematic operation of the mind. Such an advance as we may unquestionably make may not quite compare with such an ideal system as Dr. Reid's, viz., that of the whole body of air in a room being maintained at uniform temperature and pressure, as- scending, passing away, and being replaced without the slightest perceptible motion ; but, if we have no option but to submit meekly to the laws of development, we can make the very satisfactory reflection that we leave something for our successors to attempt, and can be thankful if less refined but effectual methods may secure for our ruder natures a due supply of fresh air.
A short series of ventilating contrivances, not applicable to ordinary apartments, and but seldom applied to dwelling- houses, have often been used with advantage over the ceiling of a public school-room, workshop, or room of assembly, &c. The first of these is Mr. McKinnell's venti- lator, fig. 93. It consists of two concentric tubes, the inner one longer but much smaller than the other. They
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are attached to the roof so that both of them may commu- nicate with the chamber below, and with the external air. When from any cause the air in the room has a less pres- sure than that without, a movement of air takes place in the tubes ; air is found to descend the short space between the tubes, and an ascent of air often takes place within the inner tube. As the air enters the chamber it is deflected, as shown in the figure, that the persons situated below may not be inconvenienced by draught. If the double current could always be depended upon, the contrivance would be of considerable value, but its action is liable to be disturbed by common causes. The only reason why air passes away at the inner tube is because it does not pass away by the chimney or other means. The con- trivance acts best in a perfectly close room. If a consider- able quantity of air is allowed to enter the chamber, the balance of currents becomes disturbed, and both channels may serve for the exit of air or for a gentle interchange. If, on the other hand, a fire exhausts the air in the room, there is a descending current in both tubes. A sufficient and independent supply of air for the fire must then be provided. Mr. McKinell's ventilator appears to have been found extensively serviceable in places where the require- ments with respect to ventilation are greater than in dwelling-houses, and where the chimney, windows, and doors have not offered sufficient facilities. Figs. 95 and 96 represent a similar system, known as Muir's, which has four compartments for the movement of air.
A similar contrivance by Mr. Watson, figs. 97 and 98, consists of a tube divided in the middle. A useful arrange- ment for ventilating also by a double current was devised by Mr. Thomas Harris, the architect, and patented with his consent by Mr. John Davis. In this case an external wall is used instead of the roof. Figs. 99, 100, and 101 represent a frame of iron or other material in two com-
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partments, each compartment being provided with a series of apertures and valves by which air can either enter or escape. The lower valves open inwards, and therefore admit air. The upper valves open outwards and allow it to escape. The valves require to be accurately poised, so as to yield to a slight preponderating pressure. The con- trivance, if very carefully made, is found to be highly useful. It is generally known that when a door is opened air enters the room at the bottom, and air passes out above. The same thing may occur on opening a window above and below, and some have therefore suggested the ventilation of rooms by applying perforated zinc or gauze at the bottom and top of a window sash. Messrs. Harris and Davis' ventilator is founded upon the same principle, which is of course identical with Mr. McKinnell's. Like Mr. McKinnell's ventilator, it is adapted for school-rooms, and places requiring a similar amount of ventilation, but for its success to be insured, the apertures for admitting air must have a larger total area than the apertures for the escape of air, and the supply of air to the fire in use from other sources must be quite ample.
Another ventilating contrivance used for ejecting air by mechanical power, is set in motion by the wind. Fig. 94 represents Mr. Chadwick's Archimedean screw ventilator, which is attached to the roof of a building. The upper portion is made to revolve like a common chimney cowl. Certain blades or fans within propel the air in an upward direction, and occasion thereby an ascending current, while fresh air enters the building spontaneously below at apertures provided for it. If there were no wind, there would be a descending current, or a mere interchange of air.
Of these systems Mr. McKinnell's and Mr. Watson's ventilators have, it appears, been occasionally applied to the roof of a large house or building for the purpose of
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insuring about the stairs, passages, or hall, a considerable change of air. By large openings being made over the doorways of the various rooms, it has been sought to extend the operation of the system considerably, but though such openings would undoubtedly allow of an interchange of air, whether there were a ventilator attached to the roof or not, they could never be depended upon alone for the ventilation of the various chambers of a dwelling.
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CHAPTER III.
LONDON SMOKE AND FOG.
THE gloom of the winter of 1879-80 was so dis- heartening, so dangerous, or in each sense of the word, so appalling, that on a recurrence of fog just recently, some have asked whether nothing can be done to relieve our Metropolis from the pernicious