Spraying Devices and Machinery. 221 



the best work cannot be done in a bearing apple orchard, and 

 the hand pumps must be depended upon for the most efficient 

 service. But for potatoes, nursery stock, vineyards, orchards of 

 dwarf trees, these machines will amply repay their cost, and 

 with proper treatment will lessen the unpleasant features of 

 spraying to a very great degree. Wherever sufficient work is 

 at hand to warrant their purchase, they will be found indispen- 

 sable when once used. 



FIG. 34. Power sprayer. A, lever attached to the gearing ; Z>, bar moved by 

 means of a crank attached to the wheels ; BB, pumps which force the liquid 

 into the discharge hose ; C, tank. 



As has already been stated on page 194, several machines 

 have been built for the sole purpose of spraying potatoes. As a 

 rule, those in which the liquid is applied with the aid of a force 

 pump are to be preferred, although excellent machines may be 

 found among those in which the liquid flows by the force of 

 gravity. Some method of converting the fluid into a spray 

 should, however, be present. Fig. 36 represents a machine in 

 which this is done by means of a revolving brush, BB. Air 



