472 BOAED OF AGRICULTURE. [Pub. Doc. 



Extension Poles. 



In spraying trees from the ground, no nozzle which will throw 

 a spray sufficiently fine to poison thoroughly the foliage can be 

 depended upon to throw the spray to any distance, therefore some 

 apparatus to raise the nozzle into the air is a necessity. Some 

 experiments have been made with machines for the purpose of 

 raising a nozzle from forty to seventy feet. While it is not diffi- 

 cult to perfect a machine which will do this on level ground, it 

 seems impracticable to use any machine of this kind on the rough 

 and rocky hillsides in the woods of eastern Massachusetts. The 

 only machine of this sort which has been tested in the field on the 

 gypsy moth work is illustrated on Plate XI. This consists of two 

 telescoping brass tubes, each about twelve feet in length, mounted 

 on a tripod consisting of three wooden poles, the lower ends of 

 which are weighted by heavy iron piping. At the upper end of 

 the smaller and inner tube there is placed a nozzle with several 

 outlets ; at the lower end of the larger tube the spraying hose is 

 attached. This machine can be folded together and readily car- 

 ried by one man. It can be quickly set up, and when necessary 

 the inner tube can be telescoped out to nearly its full length by 

 means of a cord and pulley. By holding the hose, the sprayer 

 can then direct the nozzle at will. While this machine has dem- 

 onstrated the possibility of spraying high trees in this manner, 

 it has never come into general use on the gypsy moth work, maiuly 

 because of its liability to injury by careless handling. It is given 

 here merely to show the possibilities in this direction. The ex- 

 tension most used is a single pole twelve or fourteen feet in 

 length. This pole consists of a five-sixteenth-inch brass tube, to 

 which the hose is coupled at the lower end and the nozzle at the 

 upper. This tube is strengthened by being enclosed in a tube 

 made of white spruce wood one and one-quarter inch in diameter, 

 the pole being bound togethe by f rrules made by winding brass 

 wire closely about it and running in solder until the whole ferrule 

 is solid. This pol^ is provided with a hook at the top, so that in 

 moving about in a tree the hose and extension can be hooked 

 onto a branch or ladder. It is also provided with two clamps, 

 which hold a rod which projects fifteen inches beyond the lower 

 end. This is done to prevent wear and tear of the hose, which 

 otherwise would soon be worn out and broken off by contact with 

 the ground. An automatic shut-off enables the sprayer to control 

 the flow of the liquid. 



