ey's invention of the saw-gin in 1794
revolutionized the business and changed the whole domestic aspect of our
Southern States. In it the fibre is picked from the seed by means of
saw-teeth projecting through slits in the side of the chamber in which
the seed-cotton is placed. But the roller-gin has again come upon the
stage, and with the late improvements is likely to become the gin of the
future. When the close of our civil war put an end to the "cotton
famine," as it was called, in Europe, and American cotton resumed its
place in the market, the export of the East Indian and Egyptian cottons
would have been immediately suppressed if they had not possessed the
roller-gin in those countries. Ten thousand of the double Macarthy gin
are used in India, and five thousand of the single roller-gin in Egypt.
It is understood that the saw-gin is used in but a single district in
India. While the saw-gin injures any variety of cotton by cutting,
tearing, napping and tangling the fibres, its action upon the long and
fine staple called "sea island" is ruinous, and the roller-gin alone is
suitable for working it. The slow action of the single roller-gin,
cleaning about one hundred and fifty pounds of lint per day, made its
cultivation too expensive, but the double roller-gin will clean nine
hundred pounds in ten hours, or one hundred and twenty pounds an hour of
the common upland short-staple cotton. It is thought by Southern members
of the United States commission that the introduction of the double
roller-gin into our country would greatly increase the profitableness of
the culture of cotton, and especially of the "sea island," which is at
present much neglected, and in the growth of which we need fear no
rivalry. Each roller is made of walrus leather, and rotates in contact
with a fixed knife, dragging by its rough surface the fibres of cotton
between itself and the knife. A grating holds the seed-cotton. Besides
these parts there are moving knives to which are attached a grid or
series of fingers. At each elevation of the moving knives, the grids
attached thereto lift the cotton to the elevation of the fixed
knife-edge and of the exposed surface of the rollers: on the descent of
each moving knife the seeds which have become separated from the fibre
are disentangled by the prongs of the moving grid passing between those
of the lower or fixed grid about seven hundred and fifty times per
minute, and are by this rapidity of action fl