700 Report oF THE [IoRTICULTURIST OF THE 
the pump apart. These pumps work somewhat harder than the 
common suction pump. The Caswell, No. 2 (see fig. 17), manu- 
factured by the Caswell Sprayer Co., Sandusky, O., is a type 
of this style of pumps. It gave good satisfaction at this Station 
the past year. The pump handle is so arranged that the weight 
of the body can be thrown on both forward and backward strokes, 
which makes the labor much easier than when the motion of the 
arms alone can be used. 
Rotary pumps are used principally on power machines. They 
are very compact and require but little room, and the awkward 
motion of the crank and crank shaft is done away with. Another 
great advantage they have over plunger pumps is that they 
require no packing whatever. When used for hand pumps they 
are worked with a crank. They are very satisfactory as long as 
the adjustments fit closely, but the parts soon wear, no matter 
what they are made of. 
A semi-rotary pump consists of a. cylinder in which is a closely 

















































——— — 
Fig. 18— The Gould Clock Pump. 
fitting, double wing, oscillating piston, with a brass valve on each 
5 
wing. The piston is operated by means of a lever, which may be 

