dl 
tory size, and may be conveniently made 4 feet long by 24 wide by 2 
deep, inside measurements. It should be carefully constrtcted, so as 
to be water-tight, and should be strengthened by four iron bolts or 
rods across the ends, one each at the top and bottom. A good double- 
acting force pump may be obtained from any of the leading pump 
manufacturers at a cost of from $10 to $20, depending upon whether 
of iron or brass and the nature of its fittings. For use in very large 
orchards or in city parks it may be advisable to construct the tank of 
twice the capacity mentioned, to expedite the spraying and to avoid 
the more frequent refillings necessary with the smaller tank. 
Lo 



YY ly 

Fic. 6.—Gasoline power spraying outfit of the Division of Entomology, U. S. Department of 
Agriculture (author’s illustration). 
For the requirements last mentioned the use of power spraying 
apparatus of considerable capacity has become somewhat general, par- 
ticularly in municipal work against shade-tree insects in the East and 
in spraying the large citrus groves of the Pacific slope. An apparatus 
of this sort recently built by the Division of Entomology of the 
Department is illustrated in the accompanying figure (fig. 6). The 
use of power apparatus for spraying is a special subject, and those 
interested would do well to consult the article by Dr. L. O. Howard 
(Yearbook Dept. Agric., 1896, pp. 69-88) giving full descriptive details, 
with figures, of the important machines now in use. 
The more economical spray tips in the amount of liquid required 
