1854.] 



ON THE WARMING AND VENTILATING OF SCHOOLS. 



101 



formula for lievrite. In the present specimen, the lime ordi- 

 narily present, is replaced by protosyd of iron and magnesia. 



On the "WarTTiing and Ventilating of Schools. 



By Neil Abnott, M.D., F.R.S. 



The lecturer began by remarking that it would be difficult 

 to overrate the importance to this and all countries which have 

 a cold winter season, of the arts of wai-iuing and ventilating, 

 but that as yet, although scientific men judge correctly in re- 

 gard to them, the mass of the people nowhere suspect the true 

 magnitude of the evils springing from the existing defects. 

 The public may be shocked occasionally by hearing of multi- 

 tudes perishing from jail or ship fevers, or cholera, gei erated 

 in confined air, and been in crowded and ill-ventilated churches, 

 concert rooms, theatres, kc, but the more permanent injury to 

 health, the early mortality and the diminished enjoyment of 

 life suffered by large classes who occupy ill-ventilated dwellings, 

 manufactories, or schoolrooms, escape common notice. A cen- 

 tury ago men did not suspect the possibility of there ever being 

 on earth such steam-engines as we now possess, or railways, 

 steam-ships, gas-lights, penny postage, &o., all of which are the 

 recent fruits of human ingenuity, and chiefly of the ingenuity 

 of men in this country ; but now, when all have perceived the 

 extraordinary benefits obtained, and the evils avoided by these 

 novelties, they would deem the world much less worth living 

 in if such things did not exist ; so the time is probably not far 

 distant when in public estimation the sanitary arts of which we 

 are to speak to-day will be regarded as things of high value. 



The lecturer then observed that nature warms by the sun, 

 and is always ventilating, that is to say, removing from about 

 persons the air rendered poisonous by their breathing, or other- 

 wise, through the agency of wind, and of the warmth given to 

 the Ijreathed air ; this warmth, by causing dilatation of that 

 air, or greater lightness under the same bulk, produces a move- 

 ment upwards, and of the foul warm air departure, urged by 

 the pressure of the surrounding heavier pure air taking its place. 



Art imitates nature closely. It warms by fire, and it venti- 

 lates by using partly the natural agencies of the wind and the 

 lightness of warmed bre^h, but also by using the strong upward 

 movement in chimney flues of the hot air which has fed com- 

 bustion below, and is called smoke. This air, by being made 

 to fill the chimney flue as a light column, is pressed up by the 

 surrounding heavier atmosphere with force proportioned to the 

 difference of specific gravity and the height of the chimney. A 

 heated chimney with an open fire-place is, therefore, constantly 

 changing the air in the bottom of the room. 



The lecturer then referred to the new arrangement of the 

 op;n fire-place described in a paper read by him two months 

 ago in the hall of the Society of Arts, and which was favorably 

 received by the scientific men then assembled. He briefly re- 

 capitulated and explained, by diagram, the chief peculiarities 

 of that fire-place — 1st, Its being smokeless ; 2d, Its saving 

 much fuel ; 'M, Its having much stronger ventilating force than 

 other open fires ; and 4th, Its taking away the foul air collected 

 near the ceiling of the room instead of the purer air from below. 

 He gave his opinion that this tire-place having the dimensions 

 of its parts and adjuncts adjusted to the purpose in view, will 

 be found to be the best simple means of warming and ventilat- 

 ing schoolrooms. 



The modifications required for a school arc — 



1. The chimney ventilating valve to be larger. 



2. The chimney-flue also from above the valve to be larger 

 than below. 



3. The chimney top to be surmounted by a moving cowl, or 

 one of the fixed wind-guards, of kindred nature, which, when 

 the wind blows, produce a degree of pumping action. 



4. The large quantity of fresh air required for a schoolroom, 

 to be caused to enter in a distributed manner, or at various in- 

 lets besides the principal one near the fire — as from the ceiling 

 — or in summer by the tops of the windows opened a little on 

 the side towards the wind, or by openings near the floor ; all 

 considerable openings on the leeward side being closed. 



He remarked with respect to larger schools that — 



1. It may be necessary in winter to warm the air which 

 enters at a distance from the fire, by letting it touch the surface 

 of tubes or flat vessels of metal, filled with water, circulating 

 from a boiler at the fire. 



2. It may be expedient to use, " at certain times of no wind 

 and medium temperatures," the cheap ventilating pump, with 

 light curtain valves, which has been adopted advantageously in 

 passenger and convict ships. This pump injects or extracts 

 any desired quantity of air with mechanical certainty, and is 

 worked as easily as the bellows of a church organ. 



8. It may be desirable to economise fuel by using the more 

 complex pumping apparatus (already proved but not yet pub- 

 licly exhibited), which cauSes the vitiated hot air in passing 

 away from any crowd to give up its warmth to the pure air en- 

 tering. 



He then spoke of some other means of ventilating which are 

 useful for particular cases, and under certain circum.<tances ; 

 but which, by unskilful persons, are often deemed universally 

 applicable, and are so often employed amiss — 



1. Open Windows. — ^Often allowable in summer — in winter 

 dangerous if more than a chink at the top be opened. A thin 

 sheet of cold air entering the room aloft, will, in descending, so 

 mingle with the hot air of the room as not to be felt by pei-sons 

 below. 



2. Perforated or ope.ning window panes, or openings in the 

 wall. — The same remarks apply to these as to the window 

 opened. Such openings produce strong cold currents, where 

 there is an open iire, and foul air does not pass out bj' them. 



3. The windsail of shijis. — A capacious tube of canvas sus- 

 pended from the rigging, and leading to the spaces between 

 the decks ; the mouth, expanded by a hoop, or otherwise, is 

 kept turned to the wind. This acts powerfully in strong winds, 

 but in calms not at all. 



4. A wooden or metallic tube or shaft leading from the open 

 air into a room, and surmounted by a moveable cowl or hood, 

 of which the mouth always turns to the wind by the action of 

 the wind itself — This may be regarded as a self-adjusting wind- 

 sail of inflexible material. 



5. Two such tubes opening into the same room or cabin — 

 the mouth of one of the cowls being alwa3-s towards the wind, 

 to receive fresh air ; the mouth of the other being turned away 

 from the wind to let used air escape. The two together act 

 with double force. 



G. Mines arc commonly ventilated by two shafts, one having 

 a fire at the bottom, to render it the ascending air shaft ; the 

 other, without fire, lets fresh air descend. If there were no 

 fire, the ventilating action woidd be in many cases so imperfect, 

 that workers would not be safe below. 



7. In some eases a sintrle large shaft is made to answer the 



