GENERATING MECHANICAL POWER 95 



number of attachments to a spraying outfit of this 

 kind. A pipe suspended under the frame with a noz- 

 zle for each row is used to spray potatoes, strawberry 

 vines and other low down crops that are grown in rows. 

 When not in use 'as a portable engine it is blocked 

 firmly into place to run the regular stationary farm 

 machinery. 



HYDRAULIC RAM 



The hydraulic ram is a machine that gets its power 

 from the momentum of running water. A ram consists 

 of a pipe of large diameter, an air chamber and an- 

 other pipe of small diameter, all connected by means of 

 valves to encourage the flow of water in two different 

 directions. A supply of running water with a fall of 

 at least two feet is run through a pipe several inches 

 in diameter reaching from above the dam to the hy- 

 draulic ram, where part of the flow enters the air 

 chamber of the ram. Near the foot of the large pipe, 

 or at what might be called the tailrace, is a peculiarly 

 constructed valve that closes when running water 

 starts to pass through it. When the large valve closes 

 the water stops suddenly, which causes a back-pressure 

 sufficient to lift a check-valve to admit a certain 

 amount of water from the large supply pipe into the 

 air-chamber of the ram. 



After the flow of water is checked, the foot-valve 

 drops of its own weight, which again starts the flow 

 of water through the large pipe, and the process is 

 repeated a thousand or a million times, each time forc- 

 ing a little water through the check-valve into the air 

 chamber of the ram. The water is continually being 

 forced out into the small delivery pipe in a constant 

 stream because* of the steady pressure of the impris- 

 oned air in the air-chamber which acts as a cushion. 



