THE COTTON GIN. 
337 
THE COTTON GIN. 
It has seemed to me easy of solution that our 
cotton gin could be improved, so as to do, perhaps, 
more work, and to make better cotton, either of 
which would be an improvement. I know not 
that I can give you or your readers sufficient light 
to understand me, but if you will cast your eye to 
the diagram, and bear with me, I will attempt it. 
Saw-Plate Circle.—Fig. 63. 
This diagram I have drawn, to show how the 
teeth of the saws enter the cotton as well as how 
they leave it, and should pass out from the grate ; 
a b is a grate—the circle is a saw plate, all of 
which within the inner circle has been cut out ex¬ 
cept at some few places along where it is fitted on 
to a cylinder of wood; d is a tooth entering the 
cotton, and c is a tooth leaving the grate. The 
circle in the saw plate is 14 inches. The teeth 
are laid off with front edge, on a line with a tan¬ 
gent, to a circle of 19 inches. The cotton is placed 
in the front part of the gin stand, through which 
the saw runs, and from its force, being turned by a 
drum on one end of the cylinder, it turns the cotton 
in an opposite direction, of course, the tooth is 
more or less forced in; but the main force is not 
brought to bear until the tooth is about quitting 
the cotton at the grate c, between two of these 
each saw passes, and then pulls off the lint known 
in common as cotton. If this tooth should pass 
through the grates in going out, for it passes at c, 
with the point entering first, of course the cotton 
would be forced into the notch, and if the heel 
should enter first, no lint would be pulled off. 
The fact that many saw teeth are so shaped, and 
grates so fixed, that the tooth in leaving the box 
where the cotton is, passes through the grates 
point foremost, is why we have the nap, or curl, 
or twist, in cotton to a great extent,* another cause 
is dampness of the cotton, it is forced from the 
seed and being compressed in the tooth, the brush 
does not blow it to pieces; another reason, the 
brush has not velocity sufficient. To remedy 
these, alter the shape of the teeth, or grates, or 
the setting on of the latter, dry cotton, or give 
more velocity to the brush. 
To increase the quantity of ginned cotton, we 
would have to increase the speed; but if we do 
so, that velocity alone will tend to force the fibre 
into the heel of the tooth, and in drawing it from 
the seed to break; or in the quantity drawn 
off, to cut against the sides of the grates. My no¬ 
tion is then, to increase the size of "the saw plate to . 
12 or 16 inches, or even more; I would, if I were 
able, experiment up to 24 inches; increase the num¬ 
ber of teeth to 8 to 12 to the inch, give the brush 
velocity, this depending much on the form and num¬ 
ber of arms you give the brush. My brush you wilL 
see from actual measurement evolves near six times 
to once of the saw, it having six arms and small; but 
I should have the brush much longer than the saw 
plate, and have the bristles long and stiff, placed 
to the edge of a thin board fastened to arms, say 
four to six inches wide ; the power of making a 
current of air to blow the cotton entirely loose from 
any compactness formed by the saw tooth as well 
as to clear the saws perfectly, is what we want. 
I should have seed and motes to be dropped, 
separate of course, but in front, with no air to be 
admitted to the brush, except at each end of the 
same; thus the motes could not be blown with 
cotton, and a more controlling blast of air kept di¬ 
rectly to act on the lint. 
All gudgeons should work in boxes made to 
contain oil continually; and whether gearing by 
cogs or bands is best, should direct me whether to 
give motion to the brush by a band, or with cogs. 
I give you now the measurement of my old- 
fashioned gin-stand: 
The saw plate measures in circumference 28 inch, 
driver on the end, 30^ “ 
drum that gives motion to the brush, 50£ “ 
of the brush, 8| “ 
number of teeth in the saw plate, 124 
In giving the above, I remark here, that I made 
the drum that carries the brush band on the saw 
cylinder, larger by two inches in diameter, and re¬ 
duced that on the brush full quarter of an inch, 
thus gave the brush over one evolution more 
than when it came from the ginwright. When 
the brush has not velocity and power enough, the 
cotton will not be cleared directly from the saw 
teeth, and will be retained on the bristles. My 
addition is roughly done, but I save throwing back 
the ginned cotton in lint room nearly a half, the 
cotton being blown so much farther. 
Allow me to repeat in a kind of summary what 
I would have in a gin-stand, and assure you 
such a one I have not seen. I gave my opinion 
thus a year ago, and before such a one was 
known to any of us about here. I would have the 
saw plate some 12 to 16 inches in diameter, the 
number of teeth to the inch 8 to 12, the teeth 
straight on the front edge, filed rounding, not 
square, or inclined, as is done with rip or cross cut 
saws, and never sharpened after. The grates 
straight, and placed so as to correspond with teeth 
of the saw, which should strike the line of grates 
on leaving them perfectly parallel, at no angle. 
The brush to have velocity enough to cause the 
greatest current of air, and should be 18 to 24 
inches in diameter. The motion of the brush to 
be given by bands or cogs as it may be known by 
machinists to be best—air admitted to the brush 
at each end. I would have one set of false grates ' 
only, merely to more effectually cut off access of 
air from below or front to the brush, but not very 
close where the teeth of the saw pass through 
them. 
My running gear is cast segments on a 12-foot 
