116 The Fruit-Growers Guide-Book 



ent time the gasoline power machines have proven them- 

 selves the most effective, economical and convenient for 

 use under all ordinary conditions. On steep hillsides, how- 

 ever, the gas machine possesses decided advantages on ac- 

 count of its light weight and the nearness to the ground 

 at which the load can be carried. But such machines are 

 objectionable on account of the expense of the gas used 

 for power, and the usual lack of facilities for keeping the 

 spraying mixture thoroughly agitated while being applied. 

 With some kinds of spray mixtures, too, the gas possibly 

 causes some undesirable chemical changes. 



In the selection of a gasoline power outfit one must be 

 governed to a large extent by the amount of work that is 

 to be done with the machine and the conditions under 

 which it is performed. Where the orchard is small and the 

 interests diversified, it may be easily detached and used 

 for other purposes than that of spraying. 



The height of the wheels of the wagon carrying the 

 spraying machine needs to be considered in the selection 

 of a power machine, as well as the width of the tires. High 

 wheels reduce draft on the team, but increase the danger 

 of upsetting on steep hillsides. On plowed ground, espe- 

 cially in the spring when it is more or less muddy, wide 

 tires are an advantage, but in rocky land the narrow tired 

 wheels are much more serviceable. In this connection, no 

 matter which is the height of the wheels, or the width of 

 the tires, it is highly important that there be no waste 

 space between the frame and the engines and that the 

 frame be constructed so as to permit of the shortest pos- 

 sible turns without cramping or binding the wheels. 



The hand pumps are very much more diversified in 

 shape and construction than the engine power machines, 

 as they are adapted to a far greater variety of uses. These 

 will vary from the hand pumps which can be mounted on 

 the spraying tank, or in a barrel, or attached to a knapsack 

 and carried on one's back. 



All of the working parts should be of hard brass or 

 iron, as aluminum, which has been used in a small way, 



