264 REPORT 4, UNITED STAT. S ENTOMOLOGICAL COMMISSION. 
This brand of pump, so far as it has come to my notice, is single-acting. 
It has enjoyed a large sale and given satisfaction, especially for broad- 
cast spraying upon the cotton crop. 
Pumps having the same external pattern, but a double-acting, inter- 
nal construction, and now sold under the name " Hydronettes," throw a con- 
stant spray or solid jet, and are hence preferable instead of the single- 
acting ones, which discharge by interrupted spurts. The double-acting 
hydronettes have for some time been manufactured by Messrs. R. T. 
Deakin & Co., northwest corner Twelfth a..d Buttonwood streets, Phila- 
delphia, Pa., and by Messrs. Eumsey & Co., Seneca Falls, X. Y. Th© 
©rdinary price for the " Fountain Pumps " and " Hydronettes " has been 
from $8 to $10. 
Some double-acting Hydronettes devised by myself have increased the 
simplicity and utility of these instruments, while rendering them some- 
what cheaper and more efficient. The construction is essentially the 
same as that presented afterward in the barrel-pump in Plate XLVI, Fig. 
2, and its description ; but the arrangements of the base valve and some 
other details are different. The removable extension-tube bearing th« 
spray-nozzle, which is directed straight ahead or laterally, with reference 
to the delivery pipe, at any angle desired, is invaluable on account of the 
quality of the spray and because the poison is thus delivered at such 
a safe distance as not to endanger the operator, while its adaptability 
suits it for applying the spray to the under surfaces or otherwise as 
may be wished. This device has three interchangeable nozzles, which 
are free from the ordinary difficulty of clogging. The pump is also fur- 
nished with the same discharge devices connected with the cylinder in- 
stead of with the moving piston as in Plate XL, Fig. 6. This enables 
the jet to be held steady, whereas the reciprocating motion of the noz- 
zles unavoidable with the other pumps already referred to is annoying, 
and in poisoning under surfaces much poison is thereby misapplied and 
wasted. The use of the device is also illustrated in Plate XXXIX, Fig. 
2, where It is the poison- can hung on the shoulders, r its opening, h a 
suction-hose from the interior to the cylinder, <?, moved back and forth on 
piston, x, which is held tirm by the right hand and with its extension- 
pipe, x u, holds the nozzle, u s, to direct the spray, u s. The nozzles are 
also shown in Fig. 3 and Plate XL, Figs. 5 and 6. By another arrange- 
ment, Plate XL, Fig. G, above alluded to the extension-pipe is attached 
at n angle to the side of the discharge end of the cylinder and the suc- 
tion-hose coupling is at an angle, or preferably a curve, diverging to 45 9 
or more, to allow the hose to hang at an angle with the cylinder without 
kinking, 
Where one and the same person must at the same time direct the 
spray and also do the pumping, the telescope pumps, or hydrone» t< s, 
are preferred to the "aquapults, w "aquaject, ,? and all other forms of 
pumps. No other pumps allow the operator such freedom of action or 
facility in applying the spray in any direction or position without con- 
