2 BULLETIN 1319, U. S. DEPARTMENT OF AGRICULTURE 
The seed cotton is sucked from the farmer's wagon by a pneumatic 
conveyor into the gin building or into a storage house. In some es- 
tablishments the cotton gees through a mechanical cleaner on the 
way to the storage house, while in others the only cleaning is done 
immediately before ginning. Most of the cleaners^ are of the picker- 
roll type, consisting essentially of revolving wooden cylinders 
studded with steel spikes, but these often are supplemented by other 
devices for shaking and sifting out the broken leaves and other 
foreign matter. 
Though all of the gin plants have cleaners of the picker-roll type, 
they are used in different ways. The seed cotton may be run 
through three of these cleaners in the storage building and through 
three more in the gin house, or only the three cleaners in the gin 
house may be used. The speed of the picker rollers in different gin 
plants varies from 125 to 280 revolutions per minute. 
After cleaning, the seed cotton may be deposited on the upper 
floor or carried on a belt or a pneumatic distributor to the feeder 
box over the gins. If dropped on the floor, the cotton either is 
taken up again by a pneumatic conveyor or is pitched or shoved 
into a chute. Each chute may supply a single gin stand, or two gin 
stands may be fed from one chute if the feeding is done by hand. 
When mechanical feeders are used the cotton passes first into a 
so-called cleaner feeder with a single picker roll, which in a short- 
staple gin serves to separate the cotton and feed it to the saws. But 
for roller ginning the cotton from the cleaner feeder usually falls 
into a box in front of a special feeding device. This is an endless 
belt of canvas having projecting sharp spikes that travel up one 
side of the box and carry small masses of seed cotton to the gin roller. 
Some ginners have abandoned these special feeders and have ad- 
justed the cleaner feeders so that they keep the right quantity of 
seed cotton in front of the moving knife. 
Several variations were found in the adjustments of the knives 
to each other and to the gin roller. Some ginners adjust the gin 
so as to have a short overlap on the fixed knife and a great pres- 
sure on the roller, while others use a long overlap of the knives and 
only enough pressure to pull the cotton over the roller, with result- 
ing interruptions in the movement of the cotton, a condition termed 
"hesitation/' 
In the different establishments the speed of the crank of the mov- 
ing knife varies from 600 to 850 revolutions per minute. Most of the 
fully recognized or appreciated by manufacturers because the treatment in ginning was 
not uniform. 
In seeking the causes of the diversity there was need to check over the entire ginning 
operation, and the results may serve as the basis of further investigations of the ginning 
processes, which undoubtedly are much needed. Diagrams and brief statements of the 
general mechanical principles of roller gins are to be found in encyclopedias and other 
reference works, but Mr. Townsend's description of the gin operations apparently is the 
first detailed account of the principles, methods, and precautions that are required in 
constructing and operating roller gins. In relation to different types of cotton gins for 
use in British India an elaborate Report on Cotton Gins and on the Cleaning and 
Quality of Indian Cotton, by Dr. Forbes Watson, was published in 1879, but the Arizona 
ginning problems are not the same. The present study in Arizona was preceded by long 
experience and familiarity with roller ginning in South Carolina. As a practical result of 
the investigation, Mr. Townsend has devised an attachment for removing the lint from the 
gin roller in a manner that straightens the fiber and improves the appearance of the 
cotton, so that higher grades are secured. This attachment has been patented and dedi- 
cated to the free use of the Government and the people of the United States. The new 
device was adopted and used by two of the gin plants in the season of 1923. This may be 
considered as a practical demonstration, showing that it is possible to secure much 
greater uniformity in the appearance of the baled cotton and of the commercial samples. — 
O. F. Cook. 
