APRIL— JUNE 1857.] Observations on Cotton. 115 
the Roller Gin : and till Whitney's Saw Gin was invented many 
fine and long stapled but downy seed-cottons were abandoned by 
planters. 
The Saw Gin consists of a number of circular blades of iron, 
with teeth of about |th to Jth of an inch long set round a wooden 
cylinder, at about |ths »*f an inch distant from each other ; — the 
cylinder in the Hand Saw Gin is moved by a small wheel and pinion : 
the Saws just pass so far between the bars of an iron grating, 
against which the cotton-seed rests, as to catch hold of the wool 
and pull it thro,ugh the bars, leaving the seeds to revolve till com- 
pletely cleaned. 
The cotton is swept from the Saws by a revolving fanner ; on 
each arm of which a line of hair brushes is fixed, or any other sub- 
stance, (such as Spanish broom) that will effectually remove the 
cotton before it can be again carried through the grating. 
When these brushes are neglected the cotton gets cut, and 
its long staple injured ; they should, therefore, be often examined 
and replenished. The cleaner, lighter, and longer stapled cotton is 
blown to the distance of some yards behind the Gin, if there is 
space ; the heavier and most dirty falling immediately at the back 
of it. Thus two qualities may be obtained from the same cotton, 
at the same time. The fanner above mentioned is kept in motion 
by means of a band and pullies, connecting it with the wooden 
cylinder. By the Saw Gin any seeds, however difficult to clean by 
the Roller Gin, are swept clear of almost all the cotton on them ; 
and its operation is so expeditious, that while a man will not pick 
more than 2lbs. of wool per day by the hand, — by a small Saw Gin 
of eighteen saws he will clean from 50 to 701bs. The same Gin, 
driven by steam, or other power, will clean 300lbs. per day. 
The Roller Gin, propelled by the foot, like a turning lathe, and 
used in Demerara, formerly required the labour of seven days 
turning, besides six persons cleaning, to obtain {K)01bs. Dutch 
weight ; thus giving only 231bs. per man, and with very hard work. 
By the aid of cattle, a saving of eight or nine days labour was ef- 
fected and with very easy work for the people employed ; four well 
grown cattle being sufficient to furnish from 900 to lOOOlbs. per day 
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