WARMING AND VENTILATION. Waumrxo.—A certain temperature, constant within narrow limits, is essential for the life of warm-blooded animals, and the heat by which this temperature is maintained is produced by the vital actions of the body itself.
See ANI3IAL HEAT, TEMPERATURE OF THE BODY. , In the MSC of man, however, at least in ordinary climates, and in the civilized condition, the heat of the body, if allowed freely to escape, would be dissipated faster than it is produced; and hence arises the necessity of clothing, houses, and other means of retarding its escape. To allow the body to continue depressed in temperature beyond the natural state, instead of harden Mg, infallibly weakens its vitality, and sows the seeds of disease; and that this error is committed on a vast scale, in Britain more especially, is apparent enough. The reports of the registrar-general show that exactly as the thermometer sinks, the rate of mortality rises and certain diseases of the most fatal kind become more prevalent; the vitality, in short, of the community decreases as the warmth of the atmosphere decreases. Could this be if the means taken to arrest the waste of heat from our bodies, or to supplement it, were not, for the majority of men and women, insufficient, or injudiciously managed? This is a matter of literally "vital" moment to one and all. The economy of heat is a primary element in the art of living in health and comfort; and "no knowledge of com mon things" that we can think of can surpass in importance a right understanding of the principles and facts ou which that art rests.
Where fuel is scarce the resource against the cold of winter is thick clothing indoors as well as out. This is said to be the regular practice in China; and even in the south of Europe fires are dispensed with in -weather when we should think them absolutely necessary, and additional wrappings are considered as appropriate while sitting in the house as in the open air. But wherever fuel can be had, it is always preferred to wear within doors much the same clothing in winter as in summer, and to keep the apart ments nearly at summer temperature by artificial heat. It is this special branch of the subject, viz., the artificial warming of apartments, that we are at present to consider; and in doing so, we presume the reader to be acquainted with The more general facts regarding the generation of beat by combustion, and its diffusion, as stated in the articles COMBUSTION, FLAME, FUEL, HEAT.
The great aim, it may be premised, in all plans of warming is, as it is expressed by Dr. Arnott, " to obtain everywhere on earth at will, the temperature most congenial to the human constitution, and air as pure as blows on a hill-top." The obtaining of the desired
temperature would be comparatively easy by itself; the difficulty lies in combining warmth with pure air. Warming and ventilation are thus in some degree antagonistic operations, and are therefore best treated in one article. The various plans of warming hitherto tried may be classed under the four heads of the open fire, stoves, gas, steam and hot-water.
The Open Fire.—The first application of artificial warmth consisted, most likely, in lighting a fire of dried sticks and leaves in a grove, a cave, or other natural shelter. When tents or wigwams came to be erected, the fire would be lighted on the middle of the floor, with perhaps a bole in the roof for the smoke to escape by. This primitive arrangement may still be seen in some of the cabins of Ireland and the Scottish high lands. The Romans warmed their apartments chiefly by portable stoves or chafing dishes, without any regular exit for the smoke and fumes; and a brasier of charcoal is still the chief means of heating sitting-rooms iu Spain and Italy, which are in general without chimneys. The chimney (q.v.) is a modern invention.
The open coal-fire glowing in a grate, which is the prevalent mode of warming dwelling-houses in Britain, has an air of cheerfulness and comfort, Ind a power of con centrating the whole family in one social circle, that make it almost an object of worship; but it is not without serious drawbacks, the most serious of which is the waste of fuel it occasions. About one-half of the heat produced by a common fire ascends with the smoke—the black part of the smoke itself being an uuconsumed part of the fuel—while about a fourth of the heat which is radiated into the apartment is, in ordinary circum stances, carried into the chimney between the fire and the mantel-piece, and thus lost. It was calculated by Dr. Arnott that only about one-eighth part of the heat-producing power of the fuel used in common fires is realized, all the rest being dissipated into the surrounding atmosphere. A common fire gives also a partial kind of warmth, heating the side of the body next to it, but leaving the rest cold; and it produces draughts into our rooms which are anything but safe or agreeable. Notwithstdnding these and other acknowledged evils, the open fire continues to hold its place, partly perhaps from preju lice, partly from real points of superiority over other methods as yet practiced; and the abject of late has been not so much to do it away, as to improve it.