However, the convenience and cleanliness of electricity are fairly well known and appreciated, but the means by which electric currents may be generated economically, and by which this form of energy may be applied to bring about sufficient returns, financial and otherwise, to warrant the installation of an isolated plant for a farm or country home, are not so generally understood. Electric current may be generated by means of a dynamo, or generator, with any kind of a power-producing plant. All that the dynamo requires to enable it to produce electric current is power of some kind that may be applied in such manner and quantity as will cause the armature, or “interior core,” of the machine to rotate at a sufficiently high and uniform rate of speed. There are various kinds of power generators which will perform this work satisfactorily for isolated plants. Within the last few years the small internal combustion engine, supplemented by the electric storage battery, for stationary service, have been so much improved and simplified as to cause them to compare very favorably with the better-known types of power-producing apparatus in first cost and in reliability of operation. The extreme simplicity of both this type of engine and of the storage battery, together with the great economy in fuel consumption of these engines, the low price of fuel, and the efficiency of the battery as a device for storing the energy and delivering it in the form of electric current when needed and in the quantity required, result in a low operating cost. The advent of tax-free alcohol into the field of available fuels for use in internal combustion engines, and the growing demand for this class of fuel, indicate that it will become, in time, a strong competitor of kerosene and gasolene. At present, gasolene is the fuel most generally used for engines of this type and small-size gas engines are now manufactured by many firms. Steam power is probably the best understood of all classes of power. In many cases, especially where the fuel is very cheap, this is the best power for a farmer to have. Steam-power plants, as well as gasolene, kerosene and alcohol plants, all require personal attendance during operation and necessitate more or less frequent applications of fuel. Wind power is also a source of energy which may well be considered by the farmer who needs a small amount of power.