February, "10] BURGESS : INSECTICIDES, GYPSY MOTH 41 



minute. One and one-half inch hose is used, and nozzles similar to 

 those supplied with fire hose are fitted ^\'ith adjustable tips of %. 3-16 

 and 14-inch aperture. A U-shaped tank of from 400 to 600 gallons' 

 capacity is mounted on the front of a set of wagon trucks and the 

 machinery on the back part. 



Since this method of spraying was adopted many improvements have 

 been made by manufacturers. This has been due largely to sugges- 

 tions made by the officials engaged in the spraying work and has re- 

 sulted in a great increase in the efficiency of the machines. 



In field work it is usually desirable to use a oue-fourth-inch nozzle 

 tip and to maintain a pressure above 200 pounds. 



With an outfit of this sort about 12 acres of woodland can be 

 treated each day at a cost averaging $10 per acre. When forests 

 are sprayed it is necessary to lay long lines of hose from the machine, 

 which whenever practical is located near a supply of water. Effective 

 work has been done when the spray mixture had to be forced through 

 a hose over a quarter of a mile in length. 



Mr. D.. M. Rogers, Special Field Agent of the Bureau of Ento- 

 mology, who has charge of the gypsy moth field work in New England 

 has devised an apparatus known as a "water tower," which is 

 mounted on the top of the spray tank and is used for treating road- 

 sides. It consists of a steel tube about 20 feet long, which is attached 

 to a mast six feet high. The bearing on the mast, which is about four 

 feet from the end of the tube, is fitted with a universal joint, so that 

 the nozzle, which is attached to the outer end of the tube, can be 

 moved in any direcion desired by the operator. The short end of the 

 tube is reinforced with a quantity of lead so that the tube nearly 

 balances on the mast. The supply hose is attached to this end, and 

 by using this device it is possible to spray two miles of roadway in a 

 single day at a cost of less than $2 an acre. 



During the past few months a new sprayer has been devised and 

 built by Messrs. L. H. Worthley and Melvin A. Guptill of the Mas- 

 sachusetts State Forester's office, which has given very satisfac- 

 tory results. Special care was taken to overcome the objectionable 

 features of the machines previously built, and it was possible to do 

 this and at the same time decrease the weight of the outfit and add to 

 its efficiency. A new type of nozzle has also been devised by these 

 gentlemen and a coupling which does not reduce the diameter of the 

 hose at the point of connection. These devices will be exhibited and 

 demonstrated before the close of the meeting. 



The spraying outfit used on the gypsy-moth work should be of spe- 



