214 EEPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
struction and what now seems the best combinations of the parts of some 
of the nozzles of this group. 
First we may notice a number of eddy-jets, as involving the principles 
which seem the best for poisoning the fields, aud which are the only nozzles 
suited for applying poison properly to the under surfaces of the foliage. 
In all these the rotation chambers and the inlets and outlets of the same 
are essentially of the kinds already described, but we need to examine 
a few styles selected and illustrated to show particularly some of the 
details of construction, form, and size. 
Fig. 1, Plate XXIV, presents a plan view of one of the larger typical 
eddy-jets as cheaply made of thin sheet-metal. The spout, a, is shown 
in section to its inlet-discharge, x. The arrows indicate the course of 
the fluid through the chamber, c, and from its central outlet-discharge, s. 
The whorl of taugents is intended to show the plan of dispersion of the 
spray which flies off from the margins of the outlet, s. A plan section of 
the chamber, c, is shown also in Fig. 1, where x marks the eccentric inlet 
and one arrow shows the current of water entering from the spout, «, 
while another gives an idea of the angle of tangential discharge from 
the outlet, s. If desired, the side of the chamber might be furnished with 
an opening, closed by a lid, cap, or plug. The orifices are so large that 
clogging and cleaning out will hardly be necessary in nozzles of this 
size; but when these are reduced for small sprays suited to spraying the 
under surfaces of small plants, a means of opening the chamber to clean 
it out had better be provided. A nozzle of this pattern is very cheap, 
and in the size indicated will throw a remarkably large, fine spray for 
broadcast work, varying according to the force applied ; but with a com- 
mon syringe pump or hydronette the single jet is easily spread 30 feet 
wide and distant. Xozzles of this general style seem to be the best for 
spraying either above or beneath. 
To get extremely large aud broad sprays the orifices may be increased. 
As in Plate XXIV, Fig. 2, the capacity of the inlet, x, may equal the 
caliber of its spout, «, and the jet-hole,' s, may be much larger, leaving 
only a very narrow margin, c, to represent the excurrent face. With 
such an outlet the angle of dispersion is very much wider and the widest 
sprays for broadcast throwing can be made. 
But for all ordinary purposes there is no need of making the nozzle 
of such large size. Indeed, the very small size shown in Plate XXV, Fig. 
4, gives a very large spray well suited for broadcast work. A plan sec- 
tion of the same is shown also. In both figures a marks the spout, or 
its eccentric, tangential inlet to the chamber, c e, and s the outlet. The 
chamber is formed in a removable plug, inserted into the cap, which is 
fixed to tlie spout, a. The tangential inlet perforates both the plug and 
the cap, while the central outlet perforates the cap only. 
A nozzle of the same style, but with a smaller outlet, is represented 
in Plate XXV, Pig. 2. This and those in Figs. 1, and C> will exhibit 
what are suitable standard sizes for small jets to throw poison upward 
