82 Kansas Academy of Science. 



of earthy elements, which are either formed among the rocks as 

 long fibrous filaments, or may be manufactured by processes analo- 

 gous to that employed in making gas-mantles. We may employ 

 sawdust, cork cuttings, also the fibers of plants, as cotton, hemp, 

 etc., or may use animal products, as wool, fur, felt, and feathers; 

 but in all these the efficacy will be determined by their porous 

 qualities, i. e., by the included air-spaces. An enclosure that has 

 much to recommend it both as a non-conductor and as an antisep- 

 tic is charcoal. The makers of refrigerators have found this out, 

 and often surround the ice-chest with a stratum of charcoal. 



When cooking is confined to substances that require only the 

 boiling temperature of water, the plan of the ordinary fireless 

 cooker is sufficient, and will secure most satisfactory results; but 

 if it is desired to give a scorching temperature, as in the baking 

 of bread and pies or in the roasting of meats, it will be necessary 

 to raise the cooking inclosure to the required degree of heat either 

 by hot bricks, slabs of steatite or by a gas jet. An electric heater 

 would perhaps be the best means of any to get the oven hot, and 

 then the source of heat may be turned off, and the oven closed and 

 left to finish the cooking process more evenly and with less danger 

 of burning than in the old way. The fuel saved here is the whole 

 amount needed to run the furnace during the period of baking. 

 The old brick oven was like this in principle, but it took a large 

 amount of fuel to heat such a mass of brickwork, for there was no 

 device to prevent radiation and waste of heat, and therefore a great 

 supply must be stored up. 



There is a field for inventive genius in the construction of a 

 stove which shall be surrounded by non-conducting material, so 

 that when any desired temperature is reached the fire may be turned 

 off and the viands receive requisite cooking without further appli- 

 cation of heat. The non-conducting envelope for such an oven, 

 when it is to be adapted to all kinds of cooking, must be of some 

 non-combustible material which has the essential closed air-spaces, 

 and the mineral asbestos will at once be suggested as both cheap 

 and effective. When the boiling temperature is high enough, as 

 is the case with most kinds of food, then the restriction of our en- 

 velope to non-combustibles is not necessary, 'and we have the 

 simple requirements of the ordinary fireless cooker. Starting with 

 the boiling temperature, such an oven, properly made, will not lose 

 more than twenty-five degrees in five hours, leaving it amply hot 

 to cook cereals. When evaporation is necessary, then, of course, 

 this economy of heat is not possible, for evaporatian implies a con- 



