TESTS OF MACHINERY FOR POISONING COTTON WORMS. 41 
placed in the usual position the mule must travel on a row to have the 
two wheels straddle it properly, and this not practical. I obviated the 
objection by a pair of rough shafts set to one side, one shaft coming 
from the center of the cart and the other standing outside of the wheel ; 
thus the mule is held nearly in front of one wheel and midway between a 
pair of rows. In practice it is shown that the slight side-draft caused 
by this arrangement amounts to almost nothing. And it should be re- 
membered that it is common in the North to use side shafts on sleighs, 
buggies, &c. The apparatus is easily pulled by one mule, which should 
travel preferably in front of the right wheel. 
The personal labor required is such that the pumper may also drive 
and keep an eye on the machine behind. It is most convenient wher 
the stirrer, pump, and barrel are placed near the left side of the cart with 
the lever or pump-handle standing crosswise. The operator then only 
looks to the right and the left instead of having to look backward. The 
mule, accustomed to working in cotton, follows between the rows as a 
rule without being guided, and the pumper is free to turn him at the 
ends. In this manner one man can use the apparatus alone without 
working any harder than he should. Still, it is generally preferable to 
have a boy attendant to assist at times, and where a larger pump with 
avery wide system of pipes to supply a large number of rows is engaged 
it will be well to have two men to take turns at pumping in cases where 
a pump motor is not provided. With such labor, the adjustable under- 
spraying machines which I have devised and shall notice below were 
operated, the best hand being a mulatto who worked for fifty cents a 
day, which is a common price for cotton-field hands. Thus the labor 
cost is small, and one or two men witha machine can do much more ang 
better spraying than a large gang does by ordinary methods. 
The rapidity depends altogether on the width of the pipe-system, or 
number and width of rows supplied, or the size of the cotton, of the noz- | 
zl@-discharges and of'the pump, on the velocity or pressure applied, and 
on the speed of the mule. It may vary with any one of these details. I 
had only one pump, this rather small, and could not try the effects of 
different sizes. There was not much diversity in the cotton and it was 
below medium size. At Selma, I labored under difficulties from bad 
workmanship, from lack of available mechanics for constructing the 
devices, on which account there were bad joints in the apparatuses, which 
leaked some, and which would loosen and at times come apart when 
high pressure was applied, thus causing stoppages in the work. Under 
the circumstances the question of time and scope could not be very sat- 
isfactorily tested ; but as to the very fine small sprays for small cotton 
the following conclusions result from this experience : 
Taking nearly average sized cotton, and the parts of the apparatus of 
medium capacity, an acre and a half was poisoned in one-half an hour, 
24 feet wide being poisoned at a single drive, and the rows were quite 
short. Twice this rapidity can be attained. 
