FARM SANITATION 



521 



lighting, the electric current may be used for other purposes- 

 small motors, electric irons, etc. 



The Electric Plant. It does not seem practical to install 

 an electric plant large enough to furnish power to the various 

 machines used on the farm. Not only would the cost of in- 

 stallation be very great, but such a plant when used for light- 

 ing would be very inefficient. An electric lighting plant 

 consists primarily of a source of power or a motor of some sort, 

 a generator or dynamo to furnish 

 the current, the wiring, the lights, 

 and, under all normal conditions, 

 a storage battery to supply cur- 

 rent when the motor and gen- 

 erator are not running. 



The Source of Power. Water- 

 power makes an ideal power for 

 the plant, as it is almost always 

 very cheap. It is, however, not 

 often available; hence the princi- 

 pal source of power for the farm 

 electric plant is the gasoline or kerosene engine. These, as 

 has been shown, have developed to the point where they are 

 quite reliable, and the power is furnished in small units at 

 a very reasonable cost. Furthermore, the gasoline engine 

 requires the minimum of attention while running, which 

 is an essential feature of the entire private electric plant. 

 Definitions. In discussing an electric plant, recourse 

 must be made to some electrical terms. Electric current has 

 two properties :'(1) The pressure or the voltage, which is the 

 measure of the tendency on the part of an electric current to 

 flow; and (2) the amount of current flowing, or the amperage. 

 Thus a 110- volt lamp requires 110 volts of pressure or voltage 

 to make its filament glow brightly. If the lamp be a 16- 

 candle-power carbon filament lamp only one-half ampere will 



Fig. 



carbon filament electric lamp; B 

 is the new tungsten lamp, which 

 is much more efficient. 



