This book is designed primarily to give the farmer a practical working knowledge of electricity for use as light, heat, and power on the farm. The electric generator, the dynamo, is explained in detail; and there are chapters on electric transmission and house-wiring, by which the farm mechanic is enabled to install his own plant without the aid and expense of an expert.

With modern appliances, within the means of the average farmer, the generation of electricity, with its unique conveniences, becomes automatic, provided some dependable source of power is to be had—such as a water wheel, gasoline (or other form of internal combustion) engine, or the ordinary windmill. The water wheel is the ideal prime mover for the dynamo in isolated plants. Since water-power is running to waste on tens of thousands of our farms throughout the country, several chapters are devoted to this phase of the subject: these include descriptions and working diagrams of weirs and other simple devices for measuring the flow of streams; there are tables and formulas by which any one, with a knowledge of simple arithmetic, may determine the power to be had from falling water under given conditions; and in addition, there are diagrams showing in general the method of construction of dams, bulkheads, races, flumes, etc., from materials usually to be found on a farm. The tiny unconsidered brook that waters the farm pasture frequently possesses power enough to supply the farmstead with clean, cool, safe light in place of the dangerous, inconvenient oil lamp; a small stream capable of developing from twenty-five to fifty horsepower will supply a farmer (at practically no expense beyond the original cost of installation) not only with light, but with power for even the heavier farm operations, as threshing; and in addition will do the washing, ironing, and cooking, and at the same time keep the house warm in the coldest weather. Less than one horsepower of energy will light the farmstead; less than five horsepower of energy will provide light and small power, and take the drudgery out of the kitchen.

For those not fortunate enough to possess water-power which can be developed, there are chapters on the use of the farm gasoline engine and windmill, in connection with the modern storage battery, as sources of electric current.

It is desired to make acknowledgment for illustrations and assistance in gathering material for the book, to the editors of The Country Gentleman, Philadelphia, Pa.; The Crocker-Wheeler Company, Ampere, N. J.; The General Electric Company, Schenectady, N. Y.; the Weston Electrical Instrument Company, of Newark, N. J.; The Chase Turbine Manufacturing Company, Orange, Mass.; the C. P. Bradway Machine Works, West Stafford, Conn.; The Pelton Water Wheel Company, San Francisco and New York; the Ward Leonard Manufacturing Company, Bronxville, N. Y.; The Fairbanks, Morse Company, Chicago; and the Fitz Water Wheel Company, Hanover, Pa.