Page:Popular Science Monthly Volume 3.djvu/312

300 cooking and supply of hot water in barracks, with from two to three ounces of coal per person cooked for.

Captain Warren constructed an apparatus to boil, bake, steam, roast, and fry, and provide hot water, which, when cooking for about 100 men, required somewhere about 2¾ ozs. for each person cooked for, but, when cooking for forty men, required 6 oz. per head, and when cooking for sixteen men the average of several days amounted to 9 ozs. or 10 ozs. per man cooked for, but on one or two of these days the consumption did not exceed 5 ozs. for each person cooked for.

These apparatus supplied to the men all the cooking and hot water necessary. The results show what degree of economy has been reached in ordinary practice with soldiers, who are not proverbial for care, and what, therefore, should be the standard of economy to which we have a right to expect to attain. No doubt, private houses containing sixteen persons might require more hot water or more cooking, but according to these facts, as to ascertained consumption of fuel, the expenditure of fuel in the kitchen for a family consisting of sixteen persons might easily be reduced to 1½ or 2 tons per year, and in all these apparatus further elements of economy remain to be developed.

The conclusions, however, to which I have been led in my consideration of this question, are, that with these apparatus, and, indeed, with all kitchen-ranges in use, the waste of heat lies in the number of functions the fire has to perform. It must warm water, it must heat the oven, it must stew, and grill, or toast, and sometimes roast at the open fire, and each of these processes requires a different condition of heat. Hot water requires a temperature of 200° to 210°, a roasting-oven of about 450°, a baking-oven probably 350°; grilling is performed on a clear flame, the temperature of which is probably 1,300°. Now, when the fire is in an efficient condition to perform one of these functions, it is also in an efficient condition to perform the others, and, although, by means of dampers, it may be somewhat checked in the performance of its full functions in certain directions, there is no doubt that an enormous amount of heat is wasted through the agency of those parts which are not wanted to be in operation. When the oven is not wanted, it is affording a means for the heat to escape rapidly, especially if ventilated as a roasting-oven. The boiler is supplied with heat beyond its requirements, and generally abstracts a large quantity of spare heat, which passes off in the shape of steam. I assume that the cook closes the dampers in order, as far as possible, to limit the action of the fire when cooking is not going on, but in practice this is difficult to insure. With these combined apparatus, the fuel consumed will be in proportion to the various operations which the fire is arranged to perform, and not in proportion to the limited work required when only one or other of the operations is wanted. When, for instance, the fire is only wanted to heat water, a great waste of heat will be going on, from the heat passing off from the