New York Agricultural Experiment Station. 375 



capacity for delivering 300 gallons per hour under a pressure of 70 

 pounds. The agitator consists of two small blades similar to a pro- 

 peller-wheel blade mounted on a bronze shaft connected with the en- 

 gine by a flexible coupling. The speed can be varied at the pleasure 

 of the operator. The price of this outfit complete is $250. 



gasoline-power outfits. 



Gasoline possesses two advantages over steam as a source of 

 power in a spraying outfit. These lie in the lightness of the outfits 

 and the little attention they require while in operation. The objec- 

 tion to them is that their adaptation to spraying purposes has not yet 

 been perfected, that is, they have not yet passed the experimental 

 stage. They are, however, being rapidly perfected for spraying pur- 

 poses by a number of competent manufacturers. In the opinion of 

 users, gasolene outfits require somewhat more skill and ability to run 

 them than do steam outfits, but this is not a serious objection. 



The power in a gasoline engine is derived from the explosion of 

 gas formed by mixing gasoline and air in proper proportions in the 

 form of vapor. This vapor is drawn through a mixing valve into the 

 combustion chamber by a forward movement of the piston. The re- 

 turn stroke of the piston compresses the gases thus drawn into the 

 cylinder, and they are ignited at the proper time by an electric spark. 

 The force of this explosion drives the piston forward again and the 

 return stroke opens an exhaust valve and drives out the burned 

 gases. 



Gasoline engines are of two types, the upright and the horizontal. 

 The upright engines ofifered for spraying purposes, so far as we have 

 seen, are usually built on the general principle of the marine engine 

 and are generally, though not always, operated on the two-cycle 

 plan. They are generally run without governors, trusting to the 

 work performed by the pump to keep the speed under control rather 

 than to the friction of a paddle wheel in water. Of this type is the 



