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. TABLE OF CONTENTS PAGE INTRODUCTION xvii PART I WATER-POWER CHAPTER I A WORKING PLANT The "agriculturist"--An old chair factory--A neighbor's home-coming--The idle wheel in commission again--Light, heat and power for nothing--Advantages of electricity 3 CHAPTER II A LITTLE PROSPECTING Small amount of water required for an electric plant--Exploring, on a dull day--A rough and ready weir--What a little water will do--The water wheel and the dynamo--Electricity consumed the instant it is produced--The price of the average small plant, not counting labor 22 CHAPTER III HOW TO MEASURE WATER-POWER What is a horsepower?--How the Carthaginians manufactured horsepower--All that goes up must come down--How the sun lifts water up for us to use--Water the ideal power for generating electricity--The weir--Table for estimating flow of streams with a weir--Another method of measuring--Figuring water horsepower--The size of the wheel--What head is required--Quantity of water necessary 32 CHAPTER IV THE WATER WHEEL AND HOW TO INSTALL IT Different types of water wheels--The impulse and the reaction wheels--The impulse wheel adapted to high heads and small amount of water--Pipe lines--Table of resistance in pipes--Advantages and disadvantages of the impulse wheel--Other forms of impulse wheels--The reaction turbine, suited to low heads and large quantity of water--Its advantages and limitations--Developing a water-power project: the dam; the race; the flume; the penstock; and the tailrace--Water rights for the farmer 56 PART II ELECTRICITY CHAPTER V