yment of men without skill, and particularly with a view
to utilizing convict labor. In 1793 patents were taken out on these
inventions to secure their exclusive use for the prisons." The
testimony states that no skill was required in the use of these
machines; they were introduced into the dockyards and worked by common
laborers. It was claimed that nine tenths of the labor was saved by
the use of Bentham's machines, which proves that they were at least
effective, which cannot be said in all cases of those of modern
manufacture.

The patent of Bentham, issued in 1793, is doubtless one of the most
remarkable ones ever issued, both for the importance of the inventions
it protected and the clearness with which they and the principles on
which they operated are described. Richards, in referring to that
section of this patent which relates to rotary tools for woodcutting,
quotes the inventor as saying: "The idea of adapting the rotative
motion of a tool with more or less advantage, to give all sorts of
substances any shape that may be required, is my own, and, as I
believe, entirely new."

For those not skilled in nor acquainted with the nature and extent of
the various operations in wood conversion which come under the head of
shaping with rotary cutters, it will be difficult to convey an idea of
the invention here set forth; it includes, indeed, nearly all
operations in woodworking, and as an original invention may be said to
consist in the discovery of the fact that flat surfaces, or surfaces
of any contour, can be properly prepared by the action of rotating
tools. It is not to be wondered at that such an operation should not
have been sooner discovered, for even at the present time there are
few processes in treating material which seem so anomalous as that of
planing a flat surface with cutters revolving in a circle of a few
inches in diameter.

In reference to planing mouldings, it is said: "If the circumference
of a circular cutter be formed in the shape of any moulding, and
projecting above the bench no more than necessary, the piece being
shoved over the cutter will thus be cut to a moulding corresponding to
the cutter--that is, the reverse of it, just as a plane iron cuts the
reverse. If a plane cutter, such as that above spoken of for cutting a
groove in the breadth of a piece, be made so thick, or, as we might be
apt to say now, so broad, or so long, as to cover the whole breadth of
the piece, it will presen