most perfect methods of combustion and utilization known in the arts. But in these methods, according to standard authorities, at least five times as much of the fuel is utilized as in the average of stoves. The practical heating value of our domestic fuel may therefore be multiplied fourteen times (5 X 2·78) by using it to make water-gas.
But, again, the material actually used at Mount Vernon in making the water-gas analyzed by Professor Moore, instead of being our domestic fuel, worth from four to six dollars per ton in New York, was mostly nothing but waste coal-dust, dug up from an old "fill," where it had been used in grading the street; and when the gas product itself is reapplied to making and superheating the steam—as, of course, it will be—the use of merchantable coal may be entirely dispensed with. Of the refuse dust we have literal mountains accumulated at our coalmines and depots, as well as constant deposits at every coal-yard, which the proprietors would now be glad to have taken away gratis. Making ample allowance for the expense of appropriating these supplies of coal-dust, and allowing only the lowest price of chestnut coal for the article consumed in our stoves and furnaces, we can multiply the present equivalent for our domestic coal bill at least three times more by the gas process—less the charges for invention and organization, capital and interest, manufacturing management, and distribution. The proprietors propose to have the fuel-gas delivered at fifty cents per one thousand feet, with a good margin of profit, as it can even now be made for ten cents. Compared with illuminating coal-gas by volume, its heating power is found to be about as three to five. Hence, coal-gas at eighty-five cents would be as cheap fuel as water-gas at fifty. But, in point of profit to the maker, the difference at these prices would be greatly in favor of the water-gas; while, in another controlling matter, on the side of the consumer, it is not malapropos to say that comparisons are "odorous." The mysterious but not agreeable smell raised by a coal-gas jet of the best air-mixing or total-combustion burner, when impinging on the surface of any cooking utensil (thought by Professor Wurtz to arise perhaps from a synthetic re-formation of gas) is a serious objection to coal-gas cooking, from which water-gas is absolutely free. Its combustion is perfect, without air mixture, and without smell, "synthetic" or whatever. So far as the hydrogen is concerned, the product of combustion is pure aqueous vapor, in a quantity not likely to overcharge with moisture the atmosphere of the house. The other principal ingredient, thirty-six per cent, of carbonic oxide, becomes, of course, carbonic acid in burning, and must be conducted away.
Using a Goodwin's gas-stove to its full capacity at once as baker, broiler, and boiler—simultaneously baking bread and potatoes, boiling other vegetables and coffee, and broiling steaks and chops, sufficient for a dinner-party of "experts"—Mr. Strong found the time thirty minutes, and the consumption of gas thirty-two and a half feet, or sixty-
