GENERATING MECHANICAL POWER 97 



age tank with an overflow is necessary, so the water 

 can run away when not being drawn for use. A con- 

 stant supply through a ram demands a constant deliv- 

 ery. It is necessary to guard the water intake at the 

 dam. A fence protection around the supply pool to 

 keep live-stock or wild animals out is the first measure 

 of precaution. A fine screen surrounding the upper 

 end of the pipe that supplies water to the ram is neces- 

 sary to keep small trash from interfering with the 

 valves. 



THE FARM TRACTOR 



Farm tractors are becoming practical. Most the- 

 ories have had a try out, the junk pile has received 

 many failures and the fittest are about to survive. 

 Now, if the manufacturers will standardize the rating 

 and the important parts and improve their selling or- 

 ganizations the whole nation will profit. The success- 

 ful tractors usually have vertical engines with four 

 cylinders. They are likely to have straight spur trans- 

 mission gears, and a straight spur or chain drive, all 

 carefully protected from dust. And they will have 

 considerable surface bearing to avoid packing the soil. 

 Some tractors carry their weight mostly upon the drive 

 wheels a principle that utilizes weight to increase 

 traction. Other tractors exert a great deal of energy 

 in forcing a small, narrow front steering-wheel through 

 the soft ground. Any farmer who has pushed a loaded 

 wheelbarrow knows what that means. Some kerosene 

 tractors require a large percentage of gasoline. The 

 driver may be as much to blame as the engine. But 

 it should be corrected. 



Manufacturers should do more educational work and 

 talk less about the wonderfully marvelous and mar- 

 velously wonderful. Salesmen should study mechanics 



