SPRAYING APPARATUS. 153 



Fig. 3 represents a side view of the nozzle and a cross 

 section of the piston about three-fourths natural size. The 

 cylinder u projects at right angles from the top of the tube 

 10. This cylinder is closed at the end by a l)evelled block. 

 The orifice v is closed by a sliding piston which is composed 

 of one or two pieces. The cross section of the piston shown 

 in Fig. 7 represents the form having two parts, an inner 

 piston which can be screwed out, as represented by the dot- 

 ted line e, and an outer part or sleeve c. By turning the 

 screw s the spray can be changed instantly from a long- 

 range spray suitable for orchards to a spray fine and mist- 

 like. However the opening may be adjusted, it so remains, 

 except when obstructions become lodged in the nozzle. The 

 spring X is designed to hold the sliding valve in position 

 except when obstructions are forced into the nozzle. As 

 such obstructions prevent the passage of the fluid, the pres- 

 sure upon the walls of the opening in the nozzle instantly 

 increases. This forces the piston back from the outlet orifice 

 so that the opening >vill admit the passage of any object not 

 larger than one-fifth In' three-sixteenths inch. When the 

 obstruction passes out, the force of the spring sets the valve 

 back into position and the nozzle works again as desired. 

 The tension of the spring x can be varied by moving the ring 

 z up or down. Figs. 4 and 5 represent two pistons, each 

 composed of one piece. No. 4 is adapted for long-distance 

 work; No. 5 is adapted for short-distance work, as it 

 throws a very fine spray which cannot l^e forced to a dis- 

 tance. These parts are made to be used where a change of 

 spray is not desirable. All the pistons are interchangeable. 

 Fig. 6, Plate XXVII., represents a lighter nozzle, designed 

 for knapsack pumps. The spray is fan shaped. The advan- 

 tages of such a nozzle are evident. When the spraying is 

 done by means of a pole extension, such small particles as 

 clog some other nozzles are quickly released without any 

 delay or stopping of the puni}) or lowering the pole to clear 

 the nozzle. 



The extension nozzle consists of a metal pipe, sometimes 

 inclosed in a bamboo pole. It is made to enal)le the opera- 

 tor to raise the nozzle to a height of twelve feet or more 

 from the ground, so that orchard trees may be sprayed with- 



