Rensselaer Republican, Volume 19, Number 37, Rensselaer, Jasper County, 19 May 1887 — Evaporation of Water. [ARTICLE]

Evaporation of Water.

It is an almost universal practice to have a vessel of water attached to furnaces and stoves for the purpose of moistening the air of rooms heated by them. The common notion that the aqueous vapor purifies the air in any way is, of course, absurd; but the possibility that it may render the air heated by the furnace more healthful and easier to breathe may be worthy of consideration. The following calculation, based upon conditions actually, existing in a residence, may serve to show the fallacy of this belief. In the house referred to, eight rooms, with an aggregate capacity of 16,500 cubic feet, are heated by a hot air furnace, which evaporates one pailful of water, weighing eighteen pounds, daily. At a temperature of 70 degrees, assuming the air in the house to ,be only half saturated with moisture,, the total amount of water contained in it will be about twelve pounds. This would apparently show that the eighteen, pounds of water evaporated would have marked effect upon the hygrometric state of air, but it must be remembered that a constant current of fresh air is passing through the furnace and into the house. It would be a low estimate to assume that the air is comuletely changed every hour, and therefore dfily ah additional three-quarters of a pound of aqueous vapor Would be present in the air- at any one time, which would only increase the percentage of moisture from 50 to 53.1 per cent., an amount too small to be of any consequence. An actual test made on two successive days with the dry and wet bulb hvgrometer, showed that the percentage of moisture in the air was the same, whether water was evaporated in the furnace or not. In a close, unventilated room, the impure air may be easier tolerated by the lungs when saturated with moisture; but with the constant supply of fresh out-of-door air with which every apartment should be be supplied, any artificial addition of aqueous vapor is both unnecessary and useless; and only in very exceptional cases is it likely io produce any beneficial effect upon the health of the persons breathing it.— Popular Science Monthly. An Irishman says he can see nd earthly reason why women should not be allowed to become medical men.