400 PRODUCTIVE FARMING 



need to be changed by continual trial until an explosion is 

 obtained. In cold weather a little hot water on the carburetor 

 to warm it, will aid in the formation of gas from the fuel. 



Engines which burn kerosene or other oil are usually 

 started with a small supply of gasoline until enough heat is 

 generated to readily vaporize the fuel oil. 



Spark troubles in make-and-break engines may arise 

 from the current source failing, or to a bad connection of the 

 wires. This trouble can be tested by opening and closing 

 the circuit by hand. Watch for a good spark. 



When trouble is suspected in the jump-spark system it 

 should be tested by removing the spark plug and laying it on 

 the cylinder. Then operate the circuit breaker by hand and 

 watch for a spark. If a good spark is not seen, the trouble 

 may be in the source of the current, in the wire connections, 

 in the insulation being wet or worn, or in a dirty spark plug. 



Electric Power on Farms. As the scarcity of coal be- 

 comes more apparent the use of electricity, generated by 

 water power, will become more common. Electricity from 

 this source or from coal, is now most common on farms that 

 are near cities that are supplied with electricity. All belt- 

 driven machines may be operated by electric motors. 



Electric motors are expensive to purchase, but they have 

 a number of advantages, viz., easy to operate, always ready, 

 no power wasted, clean and compact. 



Electric Lights, Farms wired for electric power can be 

 easily lighted even without operating their own generators. 

 Electric lights in homes, barns and elsewhere, are less trouble- 

 some, less dangerous, more efficient, and more convenient 

 than the usual kerosene lamps and lanterns. 



Farm Dams and Water Power. There are thousands of 

 farms which have water power in their own streams. In 

 many places farmers have harnessed this water power by 

 building dams and running water wheels. The water wheels 

 are sometimes used directly to operate the belt-driven 



