HOUSE OF REPRESENTATIVES (REPORT UPON THE VENTILATION OF THE).

Appendix to the Journals of the House of Representatives, 1893 Session I, D-03

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1893. NEW ZEALAND.

HOUSE OF REPRESENTATIVES (REPORT UPON THE VENTILATION OF THE).

Laid on the Table by the Hon. Mr. Seddon, with leave of the House.

Mr. T. Tuknbull, F.8.1.8.A., to the Hon. the Minister for Public Works. "Sib,— Wellington, 4th May, 1893. When, two or three weeks ago, you invited me to make a report having for its object the better ventilating of the House of Bepresentatives it then appeared as if nothing could be easier, having kept all the notes and other data that I had collected in 1877-78 for that purpose ; but in looking over these afterwards, to investigate what progress had been made of late in this branch of sanitary science, I concluded that, to compile a report to be useful, it must be able to stand the test of criticism, and be in unison with the experiences of eminent sanitary engineers. If, therefore, you find it encumbered with extracts illustrating their works, and not in the usual form in which technical reports are written, I hope the motive will be allowed as sufficient excuse. I am not aware that any administration in this colony has asked any one of my profession to report on a system of ventilation for the House of Eepresentatives, though I believe that it has taken time, and has caused much expense. In the absence of any previous report, and having no knowledge of all the schemes that have been tried, and with a strong desire to find out and recommend to you a scheme of heating and ventilating your House that would insure a successful and satisfactory issue, my attention was naturally turned to England, the home of sanitary science, and to its House of Commons, a building nearly under the same conditions and used for the same purposes. Surely, I thought, something must be found in their experiences that will be instructive to us here, and my study has furnished me with the following notes : — The first attempt at any ventilation in England of which we have any notice is the attempt of Sir Christopher Wren to ventilate the old House of Commons, in 1660, by means of a foot-square hole in each corner of the ceiling, surmounted by a truncated pyramid, and communicating with a foul-air chamber above, beyond which the heated current passed through the roof. No provision was made for inlets; hence the currents of air were reversed (result, down-draughts). Dr. De la Guillar in 1736 employed an exhaust-fan to draw out the vitiated air, but his scheme was equally unsuccessful, and was soon discarded (still no inlets for fresh supply). Sir Humphrey Davy, in 1811, contrived and set up the most notable of all the schemes attempted for the efficient ventilation •of the House of Commons. The fresh air was admitted through numerous openings in the floor, and the foul air discharged by tubes in the ceiling, heated to cause quickness of discharge, whilst all windows, doors, &c, were to be kept carefully closed. This is said to be the first instance of a careful and scientific process of changing the atmosphere of inhabited interiors by equalising the inlets and outlets of air and closing all irregular openings. Davy's scheme, though an absolute failure, was founded on correct principles, and failed only through want of knowledge of applied mechanics and of atmospheric diffusion. Not long after the destruction of the House by conflagration, in the temporary Houses which succeeded, Dr. Eeid had the merit of exhibiting for the first time an air-moving mechanism equal to the demand. It was his great heated chimney 100 ft. high, and with internal area of nearly 100 ft. Its performance gave great satisfaction. Dr. Eeid, who had charge of the warming and ventilating of the new House of Commons, in his report of the sth April, 1852, remarked that " there are restrictions which the structure imposes on the natural movements of tempered air . . . in a building surrounded entirely with corridors and passages at two different levels " —suggesting the necessity of, if possible, equalising their temperature with that within the House. Sir Goldsworthy Gurney, in October, 1852, in his evidence before the Committee of the House of Commons appointed to inquire into the heating and ventilating of the House, said, " The principle of ventilation laid down is that a sufficient quantity of fresh air should be extracted under control for the requirements of the House, and arrangements so made that that quantity shall be supplied by an insensible movement under nature's law. . . . The current of cold air which comes into the building on the opening of the doors arises from the state of exhaustion of the House itself, the House itself being in a state of partial exhaustion, or minus pressure." (Is not this the cause of the down-draughts in the House of Eepresentatives, and does it not suggest the plenum system of ventilation, since so successfully and satisfactorily adopted in many buildings of this I—D. 3.

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class?) "The process of respiration constantly alters the composition of the air. . . . Thelaws of the diffusion of gases soon produce an equal division of any effluvium that may happen to be floating in a room. There is no disturbance in the air from the laws of diffusion. A cause of the unpleasant condition of the air is, that, by the partially-exhausted state of the House, it is vitiated from foreign and unprepared sources. . . . Chloride of lime is used to correct smells. The chlorine partly acts on sulpherets, but it seems to act on the principle of one smell overpowering another. Witness does not know practically of any process to cure air of its impurities." He said, " Glass cools the air in contact with it very rapidly, and it falls as a plate or sheet of cold air. The warm air is overpowered by the falling sheet of cold. The descending particles of air call after them other particles which fall in with the current. The whole increases as it descends, and forms a large descending plate of air. One sheet having come down is followed by another sheet, which is equally cooled against the glass, and comes down, and so continually follow. . . . Carbonic acid expired from the lungs will fall in a still atmosphere, though not if the atmosphere is disturbed. The skin as well as the lungs gives out carbonic-acid gas." I have quoted thus largely from Sir G. Gurney's evidence, as nearly all of it is singularly applicable to the House of Bepresentatives, and because he was a distinguished English chemist, and made many valuable discoveries in that science. In 1839 he introduced a new mode of lighting the House of Commons, and was subsequently intrusted with the lighting and ventilating of the new Houses of Parliament. His opinions are therefore of great value. Dr. Neil Arnott, author of the " Elements of Physics," &c, before the same Committee, said, "A perfect system of warming and ventilating a building required—First, means of moving through the building steadily the definite quantity of pure air known to be necessary ; secondly, means of fully distributing this air to the different rooms and compartments ; thirdly, means of properly diffusing the air in each room ; fourthly, fit means of discharging the vitiated air from the room; fifthly, means of giving the air the fit temperature ; and lastly, means of giving the air the fit moisture. The more the apparatus is rendered self-regulating, or independent of the constant watching of the attendants, the better it is likely to be, both as to the performance and economy. A hundred years ago" —this was said in October, 1852—"nobody on earth knew that there was such a , substance as oxygen in nature, now called vital air, which is one of the elements of our atmosphere, but which constitutes also four-fifths by weight of the solids forming the crust of our earth. In respiration the oxygen which enters the lungs takes from the blood there some carbon, and returns as carbonic-acid gas, which cannot safely be breathed again, and therefore has to be removed by ventilation. The natural ventilation of persons is produced by the warmth of their breath and the wind. The poisonous hot breath, being lighter than the surrounding air, is buoyed up, and the wind carries it away. Walls and roofs of houses, however, by preventing these natural movements, soon made men aware of the necessity of ventilation. Therefore, even of old, when crowds had to meet, they did so in the open air. Smaller numbers could meet under cover and be comfortable for a while if they opened the doors or windows." In looking over these old extracts I met with the following in the Civil Engineers' Journal for July, 1853: " Dr. Beid's claim for £10,250 on account of services in the ventilation of the new Houses of Parliament was cut down to £3,250, just £7,000 less than the doctor claimed. Thearbiters were Dr. Eorbes and Mr. Forsyth, who held upwards of thirty meetings before they settled the award." This seemed to me so noteworthy in its way that, as a curiosity, I include it here. Erom this date I have not been able to get much more information on the ventilation of the House of Commons until of recent years. In the absence of this, I have ventured in this place toinsert a few extracts, selected from the Builder and other magazines, tending to show the amount of attention this science is now receiving from scientific men, and the advance it has made in lat& years from the crude beginning of Sir Christopher Wren. Premising that by them I hope to prove that there is every possibility of ventilating and heating the House of Eepresentatives in a perfectly satisfactory manner, and that the solution is only a question of expenditure, and not want of information. At Parkes's Museum of Hygiene, Margaret Street, Eegent Street, Mr. George Godwin in the chair, on the 6th February, 1884, Mr. J. P. Seddon, F.E.1.8.A., said, "There is not, in my opinion, any great difficulty in ventilating theatres or other public buildings. It has been, in my opinion, in consequence of half-measures that failures have occurred. What is wanted is simply a plentiful supply of fresh air forced into every part of the interior of a building, and not to the auditorium only, together with the extraction of the foul air from the several parts where it collects. The great essential for theatre ventilation is that the whole structure, from basement to roof, should be completely filled throughout by mechanical means with pure air, regulated in temperature as required. He (Mr. Seddon) advocated strongly the plenum system of ventilation, and instanced many theatres and other buildings in America that had been successfully ventilated by this system." As theatres have had the greatest influence in the development of the science of acoustics, sohave they had with the kindred science of ventilation. As an example, I may instance the new Opera House at Vienna, which at the time it was built excelled all others, not only in its acoustic qualities, but in the purity of the atmosphere. But the new theatre at Nice now excels it in efficiency and simplicity, and, as a consequence, in economy, and is well worthy a short description :—' Buildar, London, 19th September, 1885, page 387: " The ventilation is based on the principle that the air must not be supplied irregularly and from particular points, but should be admitted in horizontal layers, which, rising gradually from the centre surface of the floor, travel slowly up to the roof, without occasioning any currents likely to disturb the spectators. But,, further, the air must be so prepared as to be in a proper condition for breathing before it is admitted into the theatre. In other words, it must be warmed in winter and cooled in summer.

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" Over the entire surface of the floor the air is admitted by means of four hundred apertures, made under each chair and protected by iron gratings, each about 10in. by 6in. The grated surface is therefore large, and consequently the air travels slowly in spite of its abundance. The air ia pumped by a mechanical ventilator. A small gas-engine suffices to put the fan in motion. In winter the air is previously warmed by hot-water coils, care being taken not to allow the temperature to exceed 62° or 65° Fahr., as thus it does not lose any of the qualities of fresh air. There is, in fact, a mixing-chamber, where the warm air is diluted with cold air that has not passed over the hot-air coils ; and, with a little personal superintendence, it is easy to obtain precisely the required temperature. During the summer the air is cooled by means of a waterpulveriser, which also adds a pleasant moisture to the atmosphere. "The theatre, it is important to note, is not warmed by the air pumped in for breathing purposes. If this were done the cooling effects of the windows, walls, and other cold surfaces would have to be heated to a higher degree than pleasant or wholesome. All the parts surrounding the auditorium, the passages behind the boxes, vestibule, &c, are carefully warmed by hot-air flues. . . . The surrounding temperature is thus maintained at about 65° Fahr. . . . No system of ventilation is provided for this part of the House. . . . Under the circumstances, the beauties of the new theatre can be enjoyed without any inconvenience. There is no fear of taking cold or of enduring the pain of a theatre headache." I cannot omit mentioning the new Sorbonne, Paris, as its great amphitheatre is found to be the greatest triumph of ventilation yet attempted. The conditions are different from those of a theatre, as instead of a stage there is a platform. When tenders were called for, the condition stipulated was that each person was to have 20 cubic metres of air per hour; and, as there were 3,000 seats to be provided for, there were to be 60,000 cubic metres of air required. Messrs. Geneste and Herscher were successful in the competition that ensued, and the three screw-fans that they provided propelled the exact quantity, and at the rate required. It is important to note that no exhaust-fan has been found necessary in the outlet-shaft: the air warmed and forced in from below naturally goes upwards. It is also to be noted that there is a large mixing-chamber where the attendants can regulate the temperature, which is usually 65° Fahr. The peculiarity of this building is that the surrounding walls are hollow, and that at 10ft. from the ground for the whole length of the interior wall there is an emission of specially-heated air which counteracts any down-currents or chill that may be created by the broad surface of the cold stone walls. For a further account of this work, with illustration, see the Lancet for the 2nd January, 1892. I here venture to include two more notices concerning the ventilation of the House of Commons, as they may have some interest for you : — Builder, sth June, 1886 : "In the second report of the Committee of the House of Commons dealing with the cause of smells, &c, in the House, the drainage was found to be the cause. In the report, the Chairman of the Board of Works is reported to have said that ' his Board did not think it necessary to ventilate, an opinion to which the Committee on the ventilation of the House will not be long able to adhere. The Committee, without echoing the groundless complaints that have been made about the ventilating system of the House (which, provided it has pure air to deal with, is really a very efficient one), point out rightly that where an extraction system is used there is a pull of air into the apartment which facilitates the ingress of contaminated air escaping from pipes or water-closets, and they recommend the substitution of propulsion which we [editor Builder] have repeatedly said is the true system to employ for public buildings. The report generally is a most sensible and practical document, which we hope will receive the attention it deserves." Builder, 13th September, 1889 : "It was asserted by one of the members of the House of Commons that the House ' was not ventilated on any systematic plan,' one of the most unjustifiable statements we ever heard, as the Commons House is well ventilated, though there might be a deficiency of fresh air in the corridors and other parts of the House. It is impossible to get a large number of people to agree about ventilation. There is always a proportion of people who are mortally afraid of draught. In the meantime we commend to the grumblers Mr. Labouchere's jaunty optimistic declaration that the ventilation is now ' absolutely perfect,' and that nothing contributed so much to health and longevity as attendance at the debates." Dealing with and overcoming down-draughts having occasioned the greatest difficulty in the ventilating of the House of Eepresentatives, one or two excerpts from the studies of well-known specialists will not be without interest: — Building Neivs, Bth July, 1887 : " It is not necessary to repeat the many objections, under certain conditions, to the system for hot-water heating as at present introduced, but I venture to say that the down-draughts are principally caused by it, and will continue to exist as long as the hot-water pipes remain." Builder, 24th January, 1885 : " Ventilation is only successfully effected when without draught,, for, if draught is felt, many people would rather have no ventilation, as the effects of draughts are palpable and immediate, while those of foul air are slow and insidious."— Farrow. Builder, 30th January, 1885 : " Baron Huddleston, in the law-courts one day, ordered all the gratings to be pasted up. Mr. Justice Grove joined his learned colleague the following week, and immediately complained of the heat, and said that he preferred draughts to suffocation." " Cold draughts may be caused not only by the incoming fresh air, but also by local currents, induced by skylights, doors, windows, &c. Their presence may often serve to condemn in the eyes of the public an otherwise carefully-planned and satisfactory system of ventilation. " The question as to the cause of down-draughts is somewhat interesting. It may be the down-draughts are caused by the warm air from below rising up and displacing the cold air at the ceiling. It might be well to inquire where it comes from —whether it might not be produced by commg in contact with the glass ; or it may be that the air above and the ascending warm air is-

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cooled so quickly by the roof-windows, &c, as to fall towards the floor very rapidly —so rapidly as to feel like a draught." This last extract, taken in conjunction with the evidence of Sir G. Gurney, struck me as so important that I made a thorough examination of all the surroundings of the House, after which I arrived at the conclusion that, though the draughts more immediately complained of may not be caused by the glass, yet, as a precautionary measure, the temperature within the lantern ought to be heated to a few degrees higher than the House, and the glass all round covered with light woollen shades. The temperature can be raised by gas-jets round the sides. This would not only have the effect of preventing down-draught from the glass, but would tend to facilitate the ventilation of the House. Again, there are over 80 superficial feet of glass in the south wall of the "Noes" lobby, which opens directly into the House. The cold plate of air from the glass falls quickly down and runs along the floor, which cold stream will flow into the House the instant the door is opened. To nullify this the glass should be covered with shades as above, and the temperature of the lobby raised as near as possible to that of the House. I could see nothing else remarkable on the ground-floor, but round the gallery-floor there are some likely causes of down-draughts. It is probable that on this floor, as in the House of Commons, the greatest difficulty has been found in dealing with down-draughts. The first likely cause I noticed was the immediate connection of the gallery with the Hansard-room. In this room there are 44 superficial feet of glass with no covering or shades. This, with the currents between the doors, will keep the temperature in the room lower than that in the House; and any abrupt opening of the door will be certain to cause a stream of air to flow from the room into the House, over the gallery, and on to the heads of the members. Again, the gallery dedicated to the reporters opens directly on to what is known as the Press-stair. This staircase acts as an air-conducting flue, and will draw its supply from every available source on the ground-floor ; and up the staircase will flow a continual stream of cold air, to diffuse itself among the lighter air above, and, being much colder and denser than the heated and attenuated air within the House, when the door into the gallery is opened the air from the stair will rush through with the same effects as the door opposite, though in a different direction. I would reason that both draughts would, in falling, meet in some locality, in front.of and to the left-hand of the Speaker, and accentuate the motion. The foregoing reasoning will equally apply to the entrance into the Speaker's Gallery. The remedy to prevent draught from these doors is to construct small lobbies with sliding doors on each side, and fitted with noiseless vulcanite sheaves of a large diameter, so as to work easily. The curtains at present hung inside these doors are of little use in preventing these draughts. There are other doors on this floor which should be made to slide as above, and one at the left hand of the Speaker, on the ground-floor. The spring with which it is fitted is too strong for its weight, and it closes with a bang, and will disturb the air for some distance round. Air. —All medical men contend that pure air is as essential to health as pure water, and Mr. Sykes, in "Public Health Problems " (1892), says that "the result of constructing buildings in such a manner that the space about them is restricted or obstructed is to cause stagnation of the air and the accumulation of impurities, inorganic and organic, dead and living organisms." If this is true of the exterior, how much more injurious must it be if any part of an interior is unventilated ? I crawled round the air-supply shaft under the House on the morning of the 20th instant, and was unable to find anything suggesting a passage for the ingress or egress of air into the compartment round which the air-shaft winds. If lam correct it must be an hermetically-sealed chamber, and well fitted for the generation of foul gases, that will ascend through any crevices in the floor, and be diffused through the House, and swell the impurities already there. The air-shaft is nearly large enough to supply a sufficiency of fresh air to the House if it were properly constructed. Mr. Farrow insists that "all air-channels must be exclusively devoted to their purposes, and should not be used or even be made so as to be available for passages. They must be clean, unobstructed, and smooth, with all angles rounded, all corners filled in, and all enlargements avoided, so as to present the least resistance to the flow of air." This air-shaft does not possess any one of these conditions. It is not smooth, it is not clean, the angles are not rounded, it is obstructed by the hot-water pipes, and lumbered by the galvanised tubes for the ingress of the external air. The flow of air is retarded by a carpet on the floor, and, worse still, by the joists of the ceiling, as each one acts as a direct check on the current. The paper on the walls I supposed to be pasted on scrim or cotton, and afterwards whitewashed. The air when I was in the shaft felt as if there were a blending of both. It is clear that in this form and condition the shaft cannot supply the House with fresh warm air, either in sufficient quantity or purity in calm weather. In such a case the air in the House must become so attenuated during a long sitting that the outer air will rush in at every door or other source, and so cause unpleasant draughts. But, more than these, the present system of introducing the air into the House is something of the crudest, as the air coming into the shaft has not time to be heated by contact with the hot-water pipes until it is required in the House, and so in it rushes, warm and cold imperfectly mixed together, the cold waves feeling to the sense like draughts. Present Outlet. —With the method constructed for the escape of the vitiated air from the House, lam afraid sufficient reflection has not been given. Two cowls for the purpose have been set up ; but when the air in the House becomes exhausted, as it soon must do in a crowded House, with all the doors shut, and an imperfect air-supply elsewhere, either one or another of these tubes will become a shaft for conducting fresh air into the House, and will continue to do so until the interior air is similar in temperature with the exterior, and so another cause of unpleasant draughts presents itself. This must result, as, by experiment, 52 cubic feet of air at 32° is about the same weight as that of 60 cubic feet at 100° (see W. J. Baldwin, on " Heating and Fittings "). Having examined every part of the House, and reasoned out every contingency that suggested itself, I have somewhat reluctantly come to the conclusion that to warm and ventilate the House of Eepresentatives satisfactorily an almost new departure will have to be made. All the authorities

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I have consulted have influenced me in coming to this conclusion. To sustain me in this view I will submit a few excerpts from their studies and experiences for your consideration. Mr. J. P. Simmance delivered a lecture at Liverpool in October, 1891, before the Association of Public Sanitary Inspectors of Great Britain, when he said, " The first essential of a good system of ventilation is that it shall not produce discomfort by causing a feeling of cold, air, even warm air, impinging to a perceptible extent upon the skin's surface, producing rapid evaporation, which causes ' a cold.' . . . A perfect system is under complete control. It must be in our power to increase the intake of air and the rapidity of its expulsion as circumstances vary. . . . No fixed rule can be adopted, but we must have a system which at will may yield a giant's power or be quiescent. It must be simple, so that every one may be able to understand it, and scientific, so that accepted philosophical formulae may enable success or failure to be reasoned out on paper ... a system so thorough that no person is obliged to inhale products of previous respirations. Then it may be looked upon as perfect, and the nearer it approaches this perfection the more worthy will it be of adoption." For a building dedicated to the purpose of public speaking, and with a certainty of protracted discussions, indubitably the foregoing described the perfection of ventilation. " Sir, give me air, might be the motto of the public speaker " ejaculated one, and a witty American divine called upon to speak at the end of a long sitting said, " While thanking the committee for the supply of air which they had provided, he would be much pleased to sample some of the leagues which the Creator had located overhead outside." Mr. Henry J. Osborne, in writing on the subject of ventilation, said, "He had been led to make some investigation into the subject. First instance the Free Trade Hall at Manchester, seating about five thousand people. This great hall has been in use for thirty years, and is one of the best-ventilated buildings in the country. The result is obvious in the freedom of the speakers from the depression inseparable from a vitiated atmosphere, and that of the audience from coughing, and other signs of irritation common elsewhere. Another example is that of the grea,t Assembly Hall at Mile. End, probably the best-ventilated hall in London. It holds about five thousand people, and, though filled to its utmost capacity, is remarkable for the comfort of the speakers and hearers secured by good ventilation. . . . Both these buildings are heated by Constantine's convoluted stove, with the remarkable result that it has been discovered that the warm-air grids arranged for heating provide in summer the requisite for fresh air, thus securing improved ventilation." The first variety of these stoves were devised and patented by Messrs. "Whitaker and Constantine in 1867. They have undergone many improvements since then, and now appear to be the most perfect of their kind. They are so arranged as to bring the maximum of heating-surface into contact with the atmospheric air, while keeping fire and air separately from each other, to the advantage of added purity to the latter. In his chapter on the development of coils and radiators, Mr. Baldwin says " The earliest hotwater radiators were coils of cast-iron pipe carried about the sides of rooms, &c, in the most primitive manner. Usually they formed a continuous circuit from the boiler round the building and back to the boiler again, the water from one coil passing into another, and so on to the end, each being somewhat cooler than the one preceding it. This is technically known as a positive circulation, meaning that it must circulate in a certain direction if it moved at all. This principle required pipes of a large diameter, otherwise the resistance would be so great from so much pipe and so many elbows the water would not pass around the circuit in a sufficient volume to keep the last part of the circuit or heating-pipe at anything like a sufficiently high temperature to be of service as a heating-surface. The objection to such a system, aside from its appearance and bulk, was that no part of the circuit could be stopped without stopping ie all. . . . It is obsolete now, and only used for special purposes." In this connection it is curious to note that, having adopted a crude or primitive system of effecting an object, how reluctant a community is to change it. It is so in England, as pointed out by Mr. Secldon. It is so here, and, I believe, everywhere outside the United States of America, where the craving for something new is almost universal. It has been so in the case of this ventilation, when, instead of adopting at once a known successful system, there have been annual efforts to render successful a system elsewhere long ago abandoned. I hope this note, is only understood as trying to describe one of the phases of our social nature. As everything hitherto done to improve the ventilation and to clear the atmosphere within the House has failed to give satisfaction, I venture to point out that, before there is any possibility of effecting such a result, there must be a basement constructed under it, having a clear height of not less than 7ft. 6in. ; that, to insure a regular steady supply of pure fresh air, mechanical means be adopted, as, for instance, by a " Blackmail's Fan," impelled by a gas-engine, with a cone regulator (2-horse power would be ample); that the plan of the basement be suitably arranged for gas-engine, fresh-air room, air-warmer, mixing-room, and fan, with the treated air-supply taken therefrom ; that the floors, walls, and ceilings be finished in smooth cement plaster. The air should be introduced from Sydney Street, as it has the clearest exposure, the air from that side being freer from dust and other impurities. Being contiguous to a sloping bank, it affords admirable facilities for dealing with its better purification. As far as I can at present judge, the position of the furnace need not be changed, if an amended system of hot-water heating be adopted, but it might be found advisable to move it as near to the centre under the House as may be possible to insure draught to the flue, if air is to be the heating medium. 2—D, 3.

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The mere hand-sketch above will show you what may be the arrangements necessary for the hot-water system ; but there should be a mesh, furnished with a water-spray, spread on the outside of the fan, to filter and catch any of the impurities from entering the shafts The sketch was suggested by an illustration in Billings's book on "Ventilating and Heating" in the Assembly Library, page 153, in which book there is much valuable information on this subject. From the sketch it is not difficult to understand that, if the basement was constructed, air of an even temperature and purity and in sufficient quantity could easily be distributed in tubes to all parts of the House. For the quantity of air to bo supplied per head, Dr. Eeid, who devised the original scheme of ventilating the House of Commons, considered that a well-distributed supply of 10 cubic feet per minute was ample. In Germany from 20 to 25 cubic feet per minute is allowed for buildings used for this purpose. In Austria 25 cubic feet per minute is allowed; and in America from 10 to 30 cubic feet per minute. These figures do not allow for gas-burners. Each burner is known to consume from 45 to 50 cubic feet per minute, and just so much more air would be required to be supplied for each burner had the House been lighted with gas. Of the quantity of air to be supplied, Dr. Parkes remarks (1892), " We cannot demand that the air of an inhabited, room shall be absolutely as pure as the outside air, for nothing short of. breathing in .the open air can insure perfect purity at every respiration. In every house there will be some impurity of air. The practical limit of purity will depend on the cost which men are willing to pay for it. If cost is disregarded an immense volume of air can be supplied by mechanical contrivances." Of the movement of supply Mr. Farrow has laid down these two rules for himself, but they appeal , to me too circumscribed: "Fresh air should never enter a room at a greater rapidity of current than 2ft. per second, while a rate of lft. per second is perceptible at the point of entry. The desirable rate of flow for a forced current in a main channel is about 600 ft. per minute, while the inlet or suction-air passage to a fan should have one and a half times the area of the outlet or distributing-duct.'' I have inquired into the velocity that air-currents may have without causing discomfort, and of what constitutes the least amount of cubic space through which the standard amount of fresh air, without motion, and of the rate that the supply-current may flow, and have in this found much diversity of opinion. Mr. Farrow, from whom I have already quoted, restricts it to two miles per hour, while Dr. Pettenkoffer, than whom there is no better authority, says that " by means of artificial ventilation air may be renewed six times per hour without creating any appreciable aircurrents." It is safe to take a mean rate of flow between these two authorities as a data to calculate from to estimate the supply required by the House. And, as I am informed that the largest number of people in the House, including members, is 250, and this only on special occasions, and even then only for a short time, the following calculations may be taken as providing for a sufficient supply of fresh air for the House when in this crowded state: — There are about 95,000 cubic feet of air in the House when unoccupied. Each individual of the 250 has therefore an initial supply of 380 cubic feet of air. And for this number of people in a hall of this size, if 1,200 cubic feet per hour be allowed for each individual, or 300,000 cubic feet per hour in the aggregate to be supplied, which I assume to be ample to maintain the air in a sufficiently pure state for respiration. Therefore, from this data the area of the main air-supply shaft must not be less than 11-34 superficial feet, and of the form prescribed by Mr. Farrow and others. The supply should be capable of being regulated to suit the number present in the House at any time. The fresh air from the main shaft can be conducted in smooth air-tight tubes, and distributed to all parts of the House, by openings at suitable places in the risers of the platform. There should also be openings placed round the walls of the House, and arranged so that the current will be given an upward direction, to counteract the effect of any downward flow of any cold air near the walls. In the foregoing report I have endeavoured to explain what will temporarily ameliorate some of the defects pointed out to me in the present ventilation of the House of Representatives, though anything attempted with the air drawn from the faulty source must necessarily be of a temporary character. I have also endeavoured briefly to describe a system of ventilation that can be relied on as a certain success, and I have quoted the best authorities on this science in support of this contention. As to the cost; I cannot give an exact estimate at this distance from the engineers, but from analogy, and of the possibility of using a part of the old material, I should suppose the work could be completed

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at from £650 to £750. There is no difficulty whatever in forming the basement, and the House is worth it. In effect it is a new building, being only about twenty-one year's old —just arrived at its majority— and, with care, may last a century yet to come. And when the new library is built, with wide corridors round the House, especially on the gallery-floor, it will compare favourably with any Legislative chamber of its size I have seen. If the new library is erected on the site it now occupies the two basements could be joined, and one system of heating and ventilating used for both. Much of what I have written is out of the usual form of technical reports, and may be thought irrelevant, but I hope not unreasonably so. To me it has been a labour of love to relate some of the incidents in the experience of others, and to show you that the science of ventilation and heating of buildings now takes an important position in the studies of the architect who wishes to keep up with the requirements of the times. I mentioned to you in conversation that I had gone into the question of ventilating the House of Representatives in 1877 and 1878. In referring to the notes I then gathered, and those now in my possession, I was surprised to mark the advance made since then in this one branch of architectural science. Knowledge has now taken the place of groping. Sir, I cannot close without thanking you for affording me another opportunity of inquiring into this question. And, in hoping that I have succeeded in indicating a way of bringing the heating and ventilating of the House of Eepresentatives to a successful issue, I have, &c, Thomas Tuknbull. Approximate Cost of Paper. —Preparation, not given; printing (1,800 copies), £4 ]os. od.

By Authority : Samueiv Costal, Government Printer for the time being, Wellington.—lB93. Price 6d?

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