[116] REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
to prevent losing it. In place of the wooden stirrer bar formerly employed I have 
made an iron one having a spring at the middle 1o clamp snugly in the eye at the 
bottom of the pump. This will not weaken with age or break/ The cord or chain 
for pulling out the bar is not essential, as by having the end bung-hole of 2 inches 
diameter a pair of tongs or pinchers can be inserted to take hold of the end of the 
stirrer and extract it. The main hose or pipe has a screw union, by which it is 
easily separable from the pump. 
The descending pipes between the rows should have flexion and torsion in their 
joints or segments or hangings. The ground beneath the cotton-rows is highly ridged, 
and the mid-furrow between each pair of rows is deep. The ground thus formed 
operates upon the lower parts of each descending pipe or its appurtenances, when 
suitably shaped, so as automatically to guide the pipe and its nozzles between the 
rows, and to follow any crooks therein even when the conveyance is not driven in 
conformity with such irregularities. This automatical adjusting is allowed to a large 
extent, even when the top of the descending pipe is firmly or non-adjustably attached, 
provided that the descending pipe be flexile in some part of its course. This was 
sfiown in the earlier flexile forked machines which were tested for this Department 
near the Atlanta exposition. For the object in question the descending pipe may be 
flexile throughout, but it is more commonly preferable to construct this pipe of stiff 
segments having one or two flexile joints, or very short hose segments ; one at its 
top, and another at about two-thirds or one-half of the way downward therefrom. 
It is also generally best to make these flexile segments or joints of three-ply or two- 
ply hose, and only of such length as to allow them to bend like knee-joints, and to 
suffer a semi-rotation or semi -torsion. This construction prevents the trailing-fork or 
other end part from getting turned upside down, or from remaining in wrong attitude 
after dragging among or over the plants in turning, and it always tends to spriug or 
throw the nozzles back to sack positions that they deliver a properly-directed spray 
into the plants. Where torsion without bending is desired in these flexile places a 
rod extending through the interior may be employed somewhat as described for cross- 
pipes aud nozzle-arms in the special report of the United States Entomological Com- 
mission that has been prepared. The arrangements and constructions referred to have 
been carefully tested this season to corroborate the results of previous experience. 
The principle involved is simple and practical in its operation, having been tested at 
Atlanta, and again this year at Selma, Ala. 
The flexile nozzle-arms of the Y- sna P e d trailing forks, which were originally de- 
signed with the llexile stems worked satisfactorily thus attached ; but when these fork- 
arms were tested on a stiffly hung pipe, the spring-rod inside soon proved too weak. 
The strong pendant X _ f° r ^ s with curved or slopiug side-arms made stiff proximally, 
and having 3-ply hose for their distal half or two-thirds, stood severe usage by all 
methods, since they were made of stronger tubing and had much stouter spring-rods 
within. The spring-rod in each arm had its distal end soldered in a short piece of 
tube abutting against the stem of the nozzle. Forks of whatever construction will 
be guided more by the ridges if the arms extend in a somewhat upward direction be- 
fore becoming horizontal at the ends beneath the plants, as the median part of the 
fork can then sink into the mid furrow and be guided by its sides. Probably nothing 
better than the pendant Y-f° r ks and T -forts can be devised for spraying upward 
through the center of the plant. An additional pair of short arms or of nozzles may 
housed with advantage to discharge from near the median line in divergent direc- 
tion upward through the tops of the plants. The simplest plan is to join these or 
the simple eddy chambers directly to the stem-pipe or its extension, low down. Such 
nozzles may be attached side by side, or in what I call a tandem gang. This is a 
series of short tubes coupled end to end, each bearing an eddy-chamber discharge. 
These may be rotated on their axes and so are adjustable to different angles. Those 
who prefer to underspray the top of the plant and care less for its base will hnd the 
tandem arrangement by itself the best device for that purpose for throwing from the 
ground, though the forks answer as well when elevated, and may also be used be- 
neath tin; base. 
The eddy-chamber nozzles seem the best sprayers available for applying the poi- 
son. These nozzles have been tested this season with the discharge-hole of various 
sizes, from one-sixty-fourth to one-eighth or an inch diameter. The smaller ori- 
fices give the finest sprays conceivable. Indeed, with high pressure, the spray van- 
ishes into vapor and steam which does not fall, but rises to seek the clouds. From 
this the damp particles of poison powder must separate and fall. But with ordinary 
pressure too lino a spray is not attained. 
With the fine strainer on the suction end of the pump, clogging materials in the 
water arc prevented from entering t he pipe system or t lie nozzles. Additional smaller 
gauze st rainers were attached to the. ends of the metal tubes in one set of pipes. 
They keep out dirt, &C, when the pipes are separated, but may not prove of impor- 
tance. The proper method is to have a completely closed system, with folding joints 
that never need to be separated, so the whole can be folded into a small compact pack- 
