PUMPS. 



39 



bored lengthwise. In these holes the plungers, B, B, 

 made of wood maple being preferable are worked by 

 rods affixed to a rocking shaft in connection with the 

 power above the ground. Between these holes a smaller 



hole, shown by the dotted 

 lines, is bored. This bore 

 is made to communicate 

 with the other two by a 

 hole bored from the out- 

 side (seen at (7, that por- 

 tion shaded and where 

 the letter is seen being 

 afterwards plugged up). 

 A leather valve is placed 

 so as to close the ports of 

 this last hole and turn the 

 current of water into the 

 pump tube. This valve is 

 inserted into a dove-tail 

 mortise, cut in the bottom 

 of the block. A slotted 

 plug, Z>, holds the valve, 

 and is placed and fixed in 

 a proper position in the 

 mortise. The lower por- 

 tion of the mortise is closed 

 with a plug. To insert 

 the slotted plug a hole is 

 bored and the bottom of 

 the block is sawed into to 

 give room to chisel away the space in which the valve works 

 back and forth. The pump tube may be a log bored and 

 inserted into the block, as shown at E. Half -inch iron 

 rods may be used to work the plungers. This simple and 

 useful pump requires for its construction only those mate- 

 rials that are available everywhere, and only such skill as 



Fig. 5. DOUBLE-ACTING FORCE PUMP. 



