PREPARATION OF THE SULPHUR SPRAYS. 157 



one of sufficient capacity to picpaie .sprays for the treatment of 500 to 

 1,000 acres of trees. 



For small orchards sulphur sprays may be prepared in barrels by 

 the use of steam. Upon a solid plank platform 3 feet wide, 12 feet 

 long, and raised 18 inches aliove the ground, place three oak barrels 

 holding ()0 gallons each. Each barrel should have a bunghole through 

 one side a))out 1 inch above the bottom, which is stopped with a long 

 wooden plug while the spray is boiling in the l)arrel. The upper 

 heads of the barrels should be removed, and each nuwbe nailed in two 

 parts to serve as a cover for the barrel M'hile the spray is being boiled. 

 Near one end of the row of barrels is set the boiler in which steam is 

 to be generated. From the dome of this boiler a steam pipe should 

 extend horizontally over the row of barrels, and not less than 2 feet 

 above them. The farther end extends downward at a right angle, by 

 means of an elbow, to within 6 inches of the bottom of the last barrel. 

 Where the pipe i)asses over the iirst and second Vmrrels, downward- 

 extending pipes are coimected by means of proper couplings, and 

 extend to within 6 inches of the jjottoms of the respective barrels 

 into which they reach. In each of the downward-extending pipes is 

 htted a valve about 18 inches above the barrels, by means of which the 

 inflow of steam may be controlled for each barrel separately. The 

 lower end of each of the pipes leading into the barrels is left open 

 for the escape of steam. With a sufficient head of steam a barrel of 

 water may be brought to the boiling point with such an appliance in 

 about five minutes. By having three barrels, as here suggested, two 

 may be kept almost constantly filled with boiling sprays, while the third 

 is filled with boiling water for use in slaking lime, filling the })arrels 

 after the sulphur is added, and reducing the spray to the required 

 amount in the spray tank. With such an appliance for boiling, pro- 

 vided the two barrels for spray are charged alternately one hour apart, 

 60 gallons of well-made spray maj^ be sent to the orchard about once an 

 hour, after allowing each lot two hours of constant boiling. In pre- 

 paring the spray for boiling, the lime is first slaked to a cream of lime 

 in the bottom of the barrel, the pulverized sulphur is stirred in, the 

 barrel is filled two-thirds full of boiling water, a top is placed over 

 the barrel, and the steam is turned on by opening the valve above the 

 barrel. Within a very few minutes the steam will bring the contents 

 to a seething boil, and this can be maintained for the two hours 

 required without danger of overheating and with little care, except of 

 course that required to maintain and regulate the steam supply. The 

 steam stirs the spray sufficiently when boiling. When thoroughly 

 boiled the bunghole near the bottom of the barrel is opened by remov- 

 ing the long plug, and the spray is drawn off into pails and strained 

 into the spray tank through a fine wire strainer. When the barrel is 

 nearly empty enough boiling water is added to make up the amount of 



