FoodNet

Handbook of domestic science and household arts for use in elementary schools

1900

Page 28

Presented as published in 1900. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
This change from liquid to gaseous state is true in the case of oil combustion, hence the wick in either lamp or oil stove should be loosely woven and fitted perfectly without crowd- ing or excess of air space in burner, otherwise air passing into the partly filled receptacle and mingling with the gas formed may ignite, causing an explosion. This explosion in miniature occurs when tjie tube of a Bunsen burner becomes heated and "catches back," that is, ignites at lower orifices. This occurs when gas is turned very low and there is not enough pressure to force the gas rapidly upward through the tube. Perfect Combustion. — The quantity of oxygen required to produce perfect combustion with most even production of heat theoretically has been demonstrated with carbon and with hydrogen separately. The results seem to show that excessive supplies of air are very wasteful of heat, for though the fuel is entirely consumed a large percentage of the heat liberated passes up the flue with the excessive draft. If not enough air passes into the burning fuel part of the carbon passes off as smoke, which is not only wasteful but actively detrimental, as the smoke collecting in the flues interferes with the circulation as well as prevents proper conduction of the heat. The quantity of air is regulated by openings in the apparatus, and a little experience and watch- fulness soon demonstrates the proper control of these open- ings. Evolution of Cooking Apparatus. — Probably primitive man, like his prototype to-day, cooked his food before or over the open fire or buried it in the hot ashes and glowing embers 50 HANDBOOK OF DOMESTIC SCIENCE as is done by campers. References in Homer seem to indicate that even then the cooking of meats was before the open fire and not in a pot suspended over the coals. It is probable that coating fish or fowl with wet clay or mud, and then covering them with live coals, first suggested the possi- bility of making a permanent covering and resulted in the makiug of crude pottery as well as the crude ovens which were heated by being placed in the hot ashes and the top covered with live coals, much as the Dutch ovens were and are used now. The modern baking apparatus, however evolved, is ar- ranged for the use of coal, oil, or gas, seldom for the use of wood only. The modern range may be so constructed that by changing the parts in the fire-box any of the fuels may be employed. Electricity. — The latest form of apparatus is heated by means of the electric current. The objection to this appa- ratus is its excessive cost. As far as the heat for cooking is concerned, the cost of heat obtained directly from the coal is more than that derived from the electric current, for, though in transforming energy liberated by burning coal into electrical energy available for heating, only about four per cent is applied, practically all of that is utilized in the cooking apparatus. On the other hand, of the total amount of heat liberated in the coal range only one * per cent is utilized in cooking. Comparing the cost of the electric current used in lighting with gas used, when the cost for electricity is ten cents per thousand watt hours, it is about equivalent to gas at $1.25 per thousand feet. Considering that in the gas stove much heat liberated is not used, the obvious conclusion seems to be in favor of the use of electricity.