66 FIELD WORK AGAINST GIPSY AND BROWN-TAIL MOTHS. 



making improvements in the outfits succeeded in interesting many 

 people in their use. 



Experiments were carried on under the direction of Mr. A. H. 

 Kirkland and Mr. L. H. Worthley, and others connected with the 

 state office in Massachusetts, and considerable work along this line 

 has been attempted by Mr. Rogers and others connected with this 

 office, and the results have been of benefit to all workers against the 

 moths. The most successful machine thus far designed is provided 

 with a multiple-cylinder (usually triplex) pump which is connected 

 by a clutch to a gasoline engine of the marine or auto type. The 

 engine is provided with two or more cylinders. The four-cycle type 

 of engine has given the most successful results. A bronze pump is 

 used, as this metal accommodates itself to sudden fluctuations in 

 pressure and is not affected as readily with arsenate of lead as those 

 made of cast iron. 



The pump must be capable of delivering 35 gallons per minute and 

 maintain a pump pressure of at least 200 pounds. This requires a 

 10-horsepower engine. Piping is arranged so that water may be 

 pumped into the tank from accessible wells, ponds, or streams, and 

 solution pumped from the tank and not discharged by the nozzle 

 returns either to the tank or into the pump suction. A large, strong 

 air-chamber is necessary in order to avoid sharp shocks to the pump 

 and also to equalize the pressure. Batteries should be placed where 

 there is as little jarring as possible, away from the heat of the engine, 

 and where water will not reach them. One of our machines has been 

 fitted with a magneto with excellent results. Engines and motors of 

 the two and four cycle types have been used and both water and air 

 cooled engines have been tested. Until recently only gas engines of 

 the stationary type were used, but last summer the two-cylinder 

 marine motor, water cooled, gave excellent results, and a four-cylin- 

 der engine of this class will perhaps be still more satisfactory. 



The agitation of the solution is accomplished by a shaft fitted with 

 2 or 3 two-bladed propellers, which passes through the lower part of 

 the tank. It is operated by the engine so that the poison is thoroughly 

 mixed. One-and-one-fourth-inch hose has been used for spraying 

 with these machines, but at the present time 1-inch hose is coming 

 into favor. The nozzle is of much the same type as that used on fire 

 hose, being fitted for interchangeable tips, varying from £-inch to 

 !-inch aperture. 



The machinery is mounted on the back part of a wagon truck, the 

 front part being occupied by a 400-gallon to 500-gallon U-shaped 

 tank. The trucks are as short as possible to accommodate the tank 

 and necessary machinery and are provided with stout springs and 

 brake. They are also built so that the front wheels will cut under 

 the tank, as this is of advantage in turning around in narrow streets. 



