SPRAYING APPARATUS. 149 



a rotary motion on the screw bearing of the inner tube, and 

 the spraying solution is forced out through the circular s[)ace 

 thus opened between the point of the inner tu])e and the 

 inner surface of the outer tube, which surround it. By 

 turning the outer tube the density of the spray and the dis- 

 tance to which it can be thrown are regulated. 



The Gem nozzle (Plate XXIV., Fig. 4) is made on the 

 same principle as the Lowell. In using these nozzles a strong 

 pressure is required to insure a fine spray. 



For spraying orchard trees and shade trees of ordinary 

 size, light hand ladders were found to be very serviceable. 

 But when the tops of tall street elms were sprayed, extension 

 ladders, thirty, forty or even sixty feet in length, were nec- 

 essary. A heavy extension ladder sixty-five feet in length, 

 such as is used by firemen, was purchased for the latter 

 purpose. This ladder could be readily and skilfully handled 

 by six men with the aid of blocks and tackle. The small 

 hand ladders were carried on the spraying wagons and the 

 larger ones by hand or upon wagons, hand-carts or wheels, 

 as was most convenient. Ladders mounted permanently 

 upon wheels could not be used to advantage on account of 

 the uneven nature of the ground where much of the spraying 

 was done. Ladders twenty to twenty-five feet in height with 

 braces so made that they could be set up like step-ladders 

 were used at first, but they were unwieldy and it was soon 

 seen that more efiective work could be done by using light 

 ladders and climbing into the trees themselves. In climbing 

 fruit and shade trees care must be taken not to injure the 

 branches. 



Machinery for Spraying Orchard Trees and Garden Plants. 



Although in spraying small gardens and orchards any good 

 tank or pump may be used, the heavy and more cumber- 

 some outfits are not necessary. A small portable tank and 

 pump which can be taken about by the operator, either 

 attached to his person or upon a wheelbarrow, will suffice 

 for all the spraying required in small estates. 



For spraying garden plants and small fruit trees the 

 " knapsack pump," which is fastened on the shoulders, 

 has been olten recommended for use in small gardens and 



