This section is from the book "The Principles And Practice Of Modern House-Construction", by G. Lister Sutcliffe. Also available from Amazon: How Your House Works: A Visual Guide to Understanding & Maintaining Your Home.
Small appliances, like kettles and other movable objects, usually get their connection by means of two flexible silk-covered wires in the form of a cord, at the end of which is a plug carrying two small metal terminals, which can be pushed into sockets fixed in different places on the wall for the purpose. This arrangement will be tatter understood by reference to the drawing of an electric fry-pan, shown in Fig. 558. By means of the current supplied through these curds water can be boiled or kept boiling on the table where it is to be actually used.
In the same way. flat-irons can be coupled by means of the flexible cord through which the current passes, and as the electricity warm, the iron while in actual use. there is no necessity for heating more than one iron, here there a considerable saving in time and labour.
Other portable objects, such as curling-iron heaters, small radiators, cigarlighters, foot-warmers, Ac, can be heated in a similar way, in any position in which they are most useful. Qua of the most .striking instances of efficiency in this direction is given by the electrical foot-warmer, which consumes a current of one ampere only, which is little more than that taken by an ordinary incandescent light; with the unit at 4d., such an arrangement in actual use would cost only 2/5d. per hour.
Fig. 567. - An Electric Kettle.
Fig. 558.- An Electric Fry-pan.
Fig. 559. - An Electric Flat-iron.
The efficiency of appliances of this description may be said almost to be perfect, since kettles and similar utensils have an efficiency of 80 to 90 per cent, and hot-plate warmers have an efficiency of from 90 to 95 per cent By using a grill arrangement of hot-plates similar to those just mentioned, a current of 5 amperes at 100 volts will, in about 10 minute-, raise the apparatus to cooking-heat, while another 10 minutes, at a slightly reduced current, will be sufficient to cook two chops, which will thus be done at an expenditure of less than ld., an amount which in many cases will hardly cover the cost of the chips used in lighting a coal-fire in an open range. Such an example, however, does not show the electric grill in its best light, as operations began with everything cold; if we continue to cook chops on the grill when the first two are finished, we shall find that the outlay will be less than ½d. per couple.
It will be manifest that heating: is almost identical with cooking, both as regards appliances and cost. The only necessity is to convert the hot cooking-plate into something possessing a more artistic appearance, and then call it a radiator.
Electric radiators are made in any shape, from the small ornamental one for the drawing-room to the long ungainly appliance used in schools or public buildings. Their utility is manifest; not only do we do away with the necessary ills consequent on a hot-water system, such as a visit to the boiler late at night to see that it is banked, leaks, smoke, etc., but we remove the danger from fire usually accruing from the use of these appar-atus. In fact, when electric heating is applied to theatres or other crowded resorts, the additional safety gained, quite apart from the matter of trouble.
Fig. 560. - Electric Radiators.
should in itself be its recommendation. An electric heating-installation has recently been fitted up at the Vaudeville Theatre in London, the " box " form of radiators being used; the temperature of the auditorium can be kept at a standard temperature of 60°, when the passages are only 40°, by the use of a current of 90.amperes, and at a cost of only three shillings an hour. A great point in favour of such an arrangement is that it only requires to be switched OB very shortly before the theatre has to be used, and can be turned off at any time during or after the performance.
Radiators for private houses, instead of being built as fixtures, are usually made portable in the shape of screens, pendants, etc. These possess the additional* advantage, by means of their flexible connection, of being moved about at will. Such a screen as the largest shown in our illustration, exposing a surface of about 9 square feet, would, at 200° Fahr., heat a room of 1350 cubic feet capacity. These radiators can attain any range of temperature from 200° to about 450° Fahrenheit.
In the choice of heating-appliances, it should be borne in mind that self-contained apparatus are much the more efficient; that is to say, those articles into the bodies of which the warming gear is actually built, as, for example, the oven shown in Fig. 556.
The more general application of electricity to cooking and warming would, undoubtedly, purify the atmosphere and reduce labour, and thus not only tend to prolong life, but to make it pleasanter and easier.