302 THE POPULAR SCIENCE MONTHLY. 



fore, of great importance to remove any causes which tend to lower 

 the inside temperature. Hence it is desirable to utilize some of the 

 heat which passes off, at above 450, into the flue, for the purpose of 

 raising the temperature of the air to be admitted into the oven. As a 

 general rule, however, and except in some apparatus, under present 

 arrangements all this heat is wasted, and it certainly cannot be utilized 

 properly so long as one fire is retained to perform so many separate 

 operations. 



The hot-plate is the third important part of the modern close cook- 

 ing-range. Count Rumford proposed that the top of a hot-plate should 

 be covered with sand, and the sand cleared away only under the sauce- 

 pans. In its present shape, the hot-plate wastes an enormous amount 

 of heat. It is wasteful, because it radiates the heat largely ; because 

 the application of heat to the saucepans is only through the bottom of 

 the saucepan, and the bottom of the saucepan is not always in imme- 

 diate contact with the flame, but is frequently allowed to receive the 

 heat through the medium of the cast-iron hot-plate, which is a very 

 moderate conductor of heat. Just consider what the difference of 

 effect is. The heat of the flame, if directly acting on the bottom of 

 the saucepan, would be 1,200 Fahr., but, unless the hot-plate is red- 

 hot, probably not above 450 will pass through, but the heat in the flue 

 which heats the hot-plate will be at 1,200, and the spare heat from the 

 flame will be wasted up the chimney. The hot-plate should be dis- 

 pensed with, if economy is to be made paramount, and charcoal burn- 

 ers substituted for it. Where gas is available, the hot-plate can be 

 dispensed with without extra trouble to the cook. The gas-burners 

 should be properly j)rotected in sunken holes, with side of fire-clay, 

 and the saucepans should be dropped into the holes, so that the full 

 effect of the heat shall be concentrated on them and round their sides, 

 and the gas should be only kept lighted so long as the operation to be 

 performed is going on. It may be assumed that one pound of coal is 

 equivalent to from 28 to 30 cubic feet of gas ; hence, as permanent fuel, 

 gas would not be economical ; but the simplicity of its application 

 makes it a very convenient fuel in cooking, and economy is obtained 

 from its use, because the full effect of the combustion can be utilized 

 as soon as the gas is lighted, the flame can be regulated to any required 

 extent, and the gas be extinguished as soon as the required operation 

 is performed. 



I have endeavored to enumerate, briefly, the economical conditions 

 which should regulate the consumption of fuel for domestic purposes. 

 By economy it is meant that, while all necessary operations of warm- 

 ing and cooking continue to be performed, the fuel employed should 

 be utilized to the utmost. In the kitchen, the daily consumption of 

 fuel, in small establishments, should not exceed half a pound of coal 

 for each person cooked for, and in large establishments the proportion 

 should be smaller. In the consumption of fuel for warming, so many 



