EXPERIMENTAL TESTS OF MACHINERY DESIGNED FOR THE DE- 
STRUCTION OF THE COTTON WORM. 
Report by W. S. BARNARD, Ph. D.* 
U. S. DEPARTMENT OF AGRICULTURE, 
ENTOMOLOGICAL DIVISION, 
Washington, D. C., August 15, 1883. 
Sir: Under your direction I have prepared and hereby submit the 
following report on the experimental tests made during the last three 
weeks near Selma, Ala. 
Respectfully, 
W.S. BARNARD, Assistant. 
©. V. RILEY, Hntomologist. 
EC Eo Ove 
The Cotton Worm machine described in the annual report for 1881-82, 
and now subjected to field tests, is shown to be suited only for cotton 
so planted that the rows are spaced apart very equally, since it lacks 
adaptability to the usual great differences of interspaces between the 
rows. Unfortunately, nothing very closely approaching ideal straight- 
ness of rows or equality of width between them can be detected in the 
South, even in such fields as are said to be “ planted perfectly true.” 
* Letter of instruction. — 
DEPARTMENT OF AGRICULTURE, 
DIVISION OF ENTOMOLOGY, 
July 14, 1883. 
Sir: You will proceed to Selma, Ala., on the 18th of this month to carry out in detail 
the verbal instructions which I have given you. These are, chiefly, to take with you 
or send all the machinery necessary to put together and operate the spraying machine 
illustrated on Plate IX of our last annual report. You will test this machine thor- 
oughly, in order to settle by experience the numerous points that have not yet had 
practical field demonstration. Thus, the most satisfactory form of nozzle, whether 
for London purple, Paris green, or kerosene emulsion, the number of rows it is found 
best to spray at once, the relative effects of finer or coarser sprays, and particularly 
the effect of petroleum, etc., etc. Be particular to ascertain the actual cost and 
actual area covered by a given amount of liquid. You will spend no time in testing 
other devices or modes of poisoning. 
* * * * * = * * 
Respectfully, 
C. V. RILEY, 
Entomologist. 
Prof. W.S. BARNARD, 
Assistant, Entomological Division. 
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