the American Institute of Electrical Engineers, Eliot, Me., July 28th, 1897. Vice-President Steinmetz in the Chair. THE ECONOMY AND UTILITY OF ELECTRICAL COOKING APPARATUS. BY JOHN PRICE JACKSON. The tests of electrical cooking apparatus detailed in this paper were made with the hope of obtaining a method of cooking that would be satisfactory with a minimum risk of fire. During the past winter a serious fire, which might readily have become disastrous, occurred in one of the buildings of the college with which the writer is connected, caused by the use of an alcohol stove. As this institution is lighted and furnished with power by electricity, it naturally was felt that such a danger should be avoided, if possible, by the use of electrical appliances. It was also desired to ascertain whether at least a portion of the cooking in the Woman's Department of the college could not be done satisfactorily by electricity. To determine these points, I procured from the American Electrical Heating Corporation, of Boston, through the courtesy of Mr. J. E. Sayles, the following pieces of apparatus: 1 oven, 13" X 9" X 18", having three heats, 3, 10 and 17. amperes respectively. 3 stoves of 2, 4 and 5 amperes respectively. 2 flatirons of 1.5 and 6 amperes capacity. 1 broiler of 12 amperes capacity. 1 curling iron of ampere capacity. The pressure used by these is 110 volts. The stoves are round disks of iron, on the under side of which the heating wires are imbedded in a non-conducting, incombustible compound. The oven is a box, so thoroughly heatinsulated that the outside metal covering never reaches a tem perature uncomfortable to the hand. The broiler is made of a corrugated metal surface, slightly tipped from the horizontal, with a drip groove at the lower edge for catching the meat juices. The flatirons are similar in construction to the stoves, the larger one having a low current switch, which enables the operator to control the heat. In all these appliances the heating coils are so arranged that the energy is largely concentrated at useful points. They are also supplied with supports and bases which will not conduct heat. The efficiencies of the two larger stoves were obtained by heating two pounds of water to the boiling point and measuring the power supplied by a calibrated wattmeter. The cooking vessels used were ordinary stewing pans, with the bases nearly of the same size as the tops of the stoves. The efficiencies, considering the ratio between the amount of heat absorbed by the water and the amount received by the stoves were: For the larger or No. 1, 48.9 per cent. 6. These efficiencies could be increased by having the pans made to fit the stoves exactly, and still further by carefully covering the pans, lids and exposed portions of the stoves with a nonconductor of heat. When it is desired to boil water, the best plan is to place an immersion coil in a properly heat-insulated pot; such an arrangement should give an efficiency of from 90 to 100 per cent. We unluckily did not have such a coil at our disposal. It was impossible to measure the cooking efficiency of the oven, but as it was merely warm on the outside after potatoes or bread had been baked and "done to a turn," the efficiency is high. In baking, the current was turned on and the oven allowed to heat for five minutes before the articles to be cooked were placed within, and the current was turned off from ten to twenty minutes before the baking was done, when the heat of the oven was sufficient to complete the operation. The broiler was manipulated in much the same manner, thus utilizing the greatest possible amount of heat. This electrical apparatus was used for several weeks in cooking most of the meals for a family of six. The following table indicates the amount of cooking done for the first breakfast, dinner and supper, respectively, and may be taken as a fair average of the whole period. All costs have been estimated on the basis of 10 cents per kilowatt hour, the average rate charged for residence electrical supply in a near-by town. The foods were not measured, as it was believed more desirable to determine whether in a long period of cooking the apparatus would prove satisfactory for a family of given size. The largest stove is designated No. 1; the next size, No. 2; the third. size, No. 3; the broiler, в and the oven, o. Four pies can be baked in the oven at an expenditure of .62 kilowatt hours and a cost of 6.2 cents or 2.05 cents per pie. Two large loaves of bread were baked with the current on the oven 50 minutes, at an expenditure of 1.22 kilowatt hours, a cost of 12.2 cents or 6.1 cents per loaf. Four rather small-sized loaves could have been baked as readily. Biscuits with about the same expenditure of energy as in the case of pies. The broiler utilized about the same amount of energy for all kinds of meat as indicated in the table. The cost of soup sufficient for the family was about 4.5 cents. The result of the whole series of meals was a cost for electricity of 13.1 cents per meal. The heating of water for washing the dishes took an additional .35 of a kilowatt hour per meal, which raises the cost to 16.6 cents per meal. To determine the relative cost of cooking with electricity and coal, the same foods were cooked on the No. 8 Othello coal stove ordinarily used by the family. The coal was carefully weighed. The results gave an average of 12.6 pounds per meal, which at $5.00 per ton gives a cost of 3.15 cents per meal. The results show the cost of cooking by coal to be about 19 per cent of the cost of cooking by electricity. Ironing was done for the same household a number of times. The heavy articles were done with the large iron; while for fancy dresses and light articles, the small iron was used. The average time taken was four hours, and the expenditure of energy in kilowatt hours was 2.27. This made the cost of the ironing 22.7 cents. An equal number of tests was made using the coal range, the fuel being carefully weighed. For the same sized wash, the ironing took five hours, at a cost of 12.25 cents. This shows the cost of energy by the use of coal to be 54 per cent. of that by electricity. The results of the cooking tests seem to indicate that for the usual cooking of a family for the whole year, the expense would be larger than would be ordinarily acceptable, notwithstanding the great advantages in other respects. However, in the following classes the utility of electrical cooking utensils should be great: 1. For light housekeeping, such as is practiced in small city apartments, and in many larger houses during the summer months, no other method presents so many desirable features. The dirt of coal and ashes, disagreeable gases and abnormal temperature due to a coal stove are entirely avoided. For such housekeeping a disk stove using 500 or 600 watts and a broiler using about 1200 watts would be sufficient for a small family and would cost from $20.00 to $30.00. A teakettle or immersion coil might be added at a cost of from $6.00 to $10.00. A special pair of wires would of necessity have to be run into the cooking room from the house or apartment supply mains. The latter would ordinarily warrant the extra call that would be made upon them in this way. For similar purposes coal oil, gas or gasoline are frequently used, but with the inherent disadvantages of greater heat in the room, offensive odors, comparative uncleanliness and danger. 2. This form of cooking apparatus could be used with facility in boarding houses and restaurants for purposes which require an even temperature such as is needed in baking griddle cakes, boiling eggs, etc. 3. Where electricity is available, nothing could be more convenient than a small electrical stove, requiring 300 or 400 watts, for the many uses to which at present the alcohol flame is put, such as the afternoon tea-kettle, chafing-dish, toaster, etc. This use of alcohol is most unsafe as regards danger from fire, and could well be discarded for electricity, which is absolutely safe when properly installed, as well as being more convenient and better in other respects. 4. In the shop, the glue pot, solder pot, brazing iron, etc., can be heated advantageously by electricity and one of the most gratifying consequences of our experiments has been the decision to put such an equipment in our college shops. 5. The test of the electrical flatirons showed them more economical than the old form, when the saving of labor is taken into account. Not only is there a saving in time, but the severity of labor is much lessened. Our experience is that a laundress who has used an electrical iron would be exceedingly unwilling to go back to the old form. A small flatiron of two or three amperes attached to the ordinary lighting fixture in a dressing room is a great convenience; and with the electric tea-kettle and curling-iron is destined to become essential in the modern home. Concerning the question whether the use of electricity had proved satisfactory in its operations in the cooking tests described, the housekeeper in charge said: "The instruments were excellent in every respect. We were able to cook more rapidly, to keep the heat at just the right point, and could readily prevent over-cooking or under-cooking. While we were using electricity. every dish was perfect. When I think of these advantages and of the cleanliness and convenience of the utensils, I sincerely hope that some of them at least may be retained in the house permanently." |