300 THE POPULAR SCIENCE MONTHLY. 



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 2f 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 con- 

 sumption 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 six- 

 teen persons might require more hot water or more cooking, but ac- 

 cording to these facts, as to ascertained consumption of fuel, the ex- 

 penditure of fuel in the kitchen for a family consisting of sixteen 

 persons might easily be reduced to 1^ 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 consid- 

 eration 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 per- 

 formed 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 rap- 

 idly, 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 as- 

 sume 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 prac- 

 tice 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 



