BOLL WEEVIL CONTROL BY USE OF POISON. : 21 
worked together es a group if some kind of torch or contractor’s 
flare is placed at the row ends to provide light. 
Another way of reducing thé amount of labor involved in hand 
dusting is by the operation of the machine from muleback. This 
has been tried on numerous occasions and is generally much more 
satisfactory than by walking. 
POWER DUSTERS. 
The earliest work on weevil poisoning was conducted entirely 
with hand guns, as very small areas were treated during the strictly 
plat-test stage of the work, Ordinarily the next step in develop- 
ment of dusting machinery would have been to produce something 
of slightly larger capacity, but owing to the rapid development of 
the work at this stage, attention was transferred from the develop- 
ment of hand guns to that of blowers of the largest possible capacity, 
namely, the engine-power machines. In this case the duster was a 
horse-drawn machine with the fan and feeder operated by a small 
gasoline engine mounted on the platform. This machine had a dis- 
tributor extending across the rear end with five nozzles spaced 44 
feet apart, thus covering approximately five rows. Several models 
of these machines were devised and placed on the market and were 
used rather extensively during 1918 and 1919. It was found that 
they would cover from 6 to 10 acres an hour while in operation but 
that the loss of time due to mechanical difficulties was so great that 
a machine seldom averaged over 40 or 50 acres for the day’s opera- 
tions. Continued use of these machines soon made it obvious that 
they were too complicated and cumbersome to be thoroughly satis- 
factory for cotton-dusting work. Probably the most serious diffi- 
culty was the gasoline engine. Another great difficulty was found 
in constructing a thoroughly satisfactory distributing system for 
spanning five rows. There was considerable length of pipe extend- 
ing out beyond the machine on both sides and as this was necessarily 
made very heavy, the weight caused almost constant breakage due 
to excessive vibrations and jarring. In many cases the distributors 
of these power dusters were cut off so as to cover only three rows 
at a time and they really treated more acreage throughout the 
season than when they were arranged to span five rows, owing to 
the greater convenience in handling the machine over the field, 
around stumps, fences, etc., and the decreased loss of time from 
breakage. 
These power machines were placed on the market at prices ranging 
from $400 to $600 and this price seemed high for the work they 
could accomplish. Consequently it was desirable to devise a machine 
which would eliminate the gasoline engine and span only three rows 
