ANNUAL RRPORT. 203 



cially designed to obviate tlic usual ol)jectiou to the large 

 and clumsy power outfits. In general such outfits consist of 

 a stationary power plant for compressing air in a tank. This 

 tank of compressed air and another one containing the spray 

 liquid is taken to the orchard on a wagon and the com])ressed 

 air used to force the liquid from the tank. Some outfits have 

 but one tank, which contains both the compressed air and the 

 spray mixture. On account of their lightness many growers 

 prefer to use these compressed air outfits. Their use has not 

 become general for the reason that too much time is lost in 

 charging and recharging the tank with air. 



With this class of outfits may be discussed the Niagara 

 gas sprayer. It is a tank outfit which utilizes compressed car- 

 bonic acid gas to force the liquid from the tank. It consists 

 of a steel tank of 50 to 250 gallons capacity and a wrought 

 iron tube containing carbonic acid gas compressed under a 

 pressure of 1500 pounds to the inch. The tubes of gas are 

 purchased from manufacturers in the cities or large towns. 

 When empty the tubes are returned. Its chief advantages 

 are lightness and simplicity of operation. It would seem to 

 be well adapted to orchard conditions in New England where 

 it is so difificult to haul the large power outfits over the hilly 

 lands. It has not become popular, however, and is used only 

 to a very limited extent. The chief objection to its use is the 

 cost and trouble of securing the compressed gas. The steel 

 tanks are very compact and much lighter than the ordinary 

 wooden tanks and are admirably suited to the use of one of 

 the more powerful hand pumps. The steel truck and tower 

 usually supplied with this outfit are also very well adapted to 

 orchard spraying. 



Horse-power Outfits. These outfits differ from hand 

 outfits in that the power for working the pumps is secured by 

 gearing the pump to a sprocket wheel attached to a wheel :>i 

 the rig or to the axle. Usually they consist of a tank, of 

 from 50 to 100 gallons capacity, mounted on a cart and hauled 

 by one horse, although many two-horse outfits are in use. They 

 are especially adapted to the spraying of field crops like po- 



