Page:Popular Science Monthly Volume 29.djvu/256

244 "The chamber under the fire should be closed by a shield or economizer" (G, Figs. 1 and 3).—This has been already spoken of, and described as the central principle which enhances greatly the value of all the rest.

"Whenever a fireplace is constructed on these principles, it must be borne in mind that a greater body of heat is accumulated about the hearth than in ordinary fireplaces. If there be the least doubt whether wooden beams may possibly run under the hearthstone, then an ash-pan should be added, with a double bottom, the space between the two plates being filled with artificial asbestus, 'slag-wool,' two inches in thickness?

"A fireplace on this construction must not be put up in a party wall, where there is no projecting chimney-breast, lest the heated back should endanger woodwork in a room at the other side."

Having now worked up rules for the construction of an effective fireplace, let us consider what benefits result.

1. Economy of Fuel.—I have already stated that my own experience of the application of the "Economizer" to all my original fireplaces, including kitchen and scullery, was a saving of more than one fourth. Friends who have followed my advice report variously from a sixth to one third. The saving in the Leeds Infirmary, according to returns supplied to me by Mr. Blair, the general manager, has been nearly a sixth, amounting to nearly one hundred tons in the year. What the saving in the fireplaces constructed on the best rules may be I can not say, probably about the same degree of saving, with a large increase of heat given into the room. My conviction is that such fireplaces make one ton of coal give out as much heat into a room as two tons would yield if burned in the worst forms of the nearly obsolete register-stove.

2. Reduction of Soot.—This is, perhaps, from a national point of view, the most important point in connection with our subject—and yet it is the portion of it in which my evidence is the most defective. I can only offer you my general impression that there is a very important reduction in the amount of soot, an impression based upon observation of the smoke issuing from chimneys where "Economizers" are in use, and of the diminution of soot falling about my own house, which is confirmed by the testimony of Miss Gordon, Lady Superintendent of the Leeds Infirmary, as to the lessened amount of soot which finds its way into the wards.

3. Reduction of Ash-pit Refuse.—This point is clearly proved by the fine, snuff-like powder, free from cinders, which I show; and by the fact that the whole produce in the ash-pit of my kitchen fireplace for one week was contained in one ash-pan, and weighed fifteen pounds.

Danger of Fire.—Seeing that improved fireplace construction involves increased heat about the hearth, an actual danger of fire will