CHAPT E R 
XI. 
MACHINERY AND DEVICES FOR T11E DESTRUCTION OF 
THE WORM. 
By Pkof. W. S. Barnard, Pu. D. Assistant. 
I. — SPRAY NOZZLES. 
Since most of the nozzles invented have been claimed independently 
of insect-destroying devices, yet are applicable for throwing poison, and 
any nozzles may be used on other machines than those they were first em- 
ployed on, it has seemed to me advisable to treat them all in a separate 
chapter, and to consider them in what 1 have found to be four natural 
classes, viz: 1. Many-punctured nozzles; 2. Slot-nozzles; 3. Deflector 
nozzles; and, 4. Centrifugal nozzles. The nozzles which at present 
seem to be the best will be described under the last of these classes. 
MANY-PUNCTURED NOZZLES. 
[Platea XIV and XV.] 
The nozzles of this class are constructed on the dissection principle, 
dividing the liquid into a group of small jets by forcing it through a 
many-punctured face. 
The best nozzles of this group are such as have the tangential en- 
trance. A removable face is of great importance ; also, the perforations 
should be made and located, or directed, according to the principles 
explained below. 
The old-fashioned sprinklers and sifters, with which all are familiar, 
whether made of perforated sheet metal or wire-gauze, have generally 
proved unpractical for administering insecticides, because of the fine 
holes becoming clogged by the poison and other materials. To prevent 
this, various stirring, shaking, and straining appliances have been com- 
bined with them, but without as good results as are to be desired. 
The manner in wiiich the holes are made often causes much trouble. 
These are sometimes so cleanly drilled or punched that little or no 
burr surrounds, them ; but usually they are so punched that on one side 
a high burr or ridge is formed around the puncture, while on the other- 
side each hole appears in the bottom of a funnel-shaped pit, which, if 
oji the inside, is excellently calculated to collect and hold particles over 
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