April, '11] worthley: woodland spraying 191 



acre this year being $6.50. Ten pounds of arsenate of lead paste 

 to 100 gallons of water was used at the beginning, and this amount 

 gradually increased to fifteen pounds at the last of the season. 



One other point must be considered in using power outfits. It is 

 iiecessary to have the engine and pump work at all times when the 

 solution is in the tank so that settling will not occur, for if poison is al- 

 lowed to settle, it is very difficult to mix it perfectly again, and the 

 poison will be unevenly distributed on the foliage. In woodland 

 colonies after the thinning and creosoting methods have been applied, 

 roads must be built, so that the apparatus can be used, and the colony 

 sprayed with a reasonable length of hose. The building of the roads 

 last year was done at a cost of 3 1-7 cents per square yard. We find 

 it necessary to see that the poison is well mixed before weighing and 

 placing it in the spray tank, because in numerous cases we have 

 noticed that where large barrels of arsenate of lead have been allowed 

 to stand for any length of time, the poison has settled to the bottoms 

 of the barrels, thus making it very hard to mix properly when wanted 

 for use. We are now experimenting with a mechanical device which 

 can be attached to the outfit, worked by the power from the engine, 

 to mix the poison thoroughly before it is taken from the barrel. If 

 this is not properly done, the first half of the barrel will not have 

 sufficient strength to give good results in killing the caterpillars. 



The nozzle, which is used in our work, is another very essential 

 point to be considered, as in previous years we have been obhged to 

 climb the trees to a considerable extent, even when the solid stream 

 was used. This was due to the fact that there was so much resistance 

 in the nozzle that it would not give a stream of sufficient height, it 

 being broken up and spread out immediately after leaving the tip of 

 the nozzle. This year, we designed a nozzle, which has given excellent 

 results. The first point which was considered was to eliminate as 

 much of the resistance as possible, that is, having a full inch water- 

 way direct to the tip. The shut-off and base of the nozzle, and the 

 brass tubing running to the tip are each one inch internal diameter. 

 At the top of this brass tubing is what is known as a "Hopkins," 

 which stops the whirl of the water inside, and the tip is of an even 

 diameter throughout, causing the stream to rise from twenty to twenty- 

 five feet without breaking, as will be noted in the photograph. The 

 proper length of the tips was a very hard matter to determine, and 

 hundreds were made and tried out before the one giving the best re- 

 sults was selected, and by means of this straight water-way in the 

 tip, we are able to spray ninety-five feet high. In our largest wood- 

 land problem this past year, w^e have experienced no trouble in spray- 

 ing the greater part without climbing. 



