There have been various contrivances for this purpose; but the best we are acquainted with is described in the Transactions of the American Philosophical Society, and is as follows:

     AAAA, fig. 315, is a bench of seasoned oak,  the face of which is planed very smooth.  BBBB the feet of the bench,  which should be substantial.  CCCC the carriage on which the files are laid, which moves along the face of the bench AAAA, parallel to it's sides, and carries the files gradually under the edge of the cutter or chisel HH, while the teeth are cut:  this carriage is made to move by a contrivance somewhat similar to that which carries the log against the saw of a saw-mill, as will be more particularly described.  DDD are three iron rods inserted into the ends of the carriage CCCC, and passing through the holes in the studs EEE, which are screwed firmly against the ends of the bench AAAA, for directing the course of the carriage CCCC, parallel to the sides of the bench.
     FF two upright pillars, mortised firmly into the bench AAAA, nearly equidistant from each end of it, near the edge, and directly opposite to each other. G the lever or arm which carries the cutter HH, ( fixed with a screw, I ) and works on the centres of two screws KK, which are fixed into the two pillars FF, in a direction  right across the bench AAAA.  By tightening or loosening these screws, the arm which carries the chisel may be made to work more or less steadily. L is the regulating screw, by means of which the files may be made courser or finer; this screw works in a stud M, which is screwed firmly upon the top of the stud F; the lower end of the screw L bears against the upper part of the arm G, and limits the height of which it can rise.
     N is a steel spring, one end of which is screwed to the other pillar F, and the other end presses against the pillar O, which is fixed upon the arm G; by it's pressure it forces the said arm upwards until it meets with the regulating screw L. P is an arm with a claw at one end marked 6, the other end is fixed by a joint into the end of the stud or pillar O, and by the motion of the arm G, is made to move the ratch-wheel Q.  This ratch-wheel is fixed upon an axis, which carries a small trundle-head or pinion R, on the opposite end; this takes into a piece SS, which is indented with teeth, and screwed firmly against one side of the carriage CCCC; by means of this piece motion is communicated to the carriage.
     F is a clamp for fastening one end of the file ZZ in the place or bed on which it is to be cut. V is another clamp or dog at the opposite end, which works by a joint W, firmly fixed into the carriage CCCC. Y is a bridge, likewise screwed into the carriage, through which the screw X passes, and presses with the lower end against the upper side of the clamp V; under which clamp the other end of the file ZZ is placed, and held firmly in its situation while it is cutting by the pressure of the said clamp V. 7777 is a bed of lead, which is let into a cavity formed in the body of the carriage, something broader and longer than the largest size files; the upper face of this bed of lead is formed variously, so as to fit the different kinds of files which may be required. At the figures 22 are two catches, which take into the teeth of the ratch-wheel Q, to prevent a recoil of its motion; 33 is a bridge to support one end, 4, of the axis of the ratch-wheel Q; 5 a stud to support the other end of the axis of that wheel.
    When the file or files are laid in their place, the machine must be regulated to cut them of the due degree of fineness, by means of the regulating screw L; which, by screwing further through the arm M, will make the files finer, and, vice versa by unscrewing it a little, will make them courser; for the arm G will, by that means, have liberty to rise the higher, which will occasion the arm P, with the claws, to move further along the periphery of the ratch-wheel, and consequently communicate a more extensive motion to the carriage CCCC, and make the files courser.

     When the machine is this adjusted, a blind man may cut a file with more exactness than can be done in the usual method by the keenest sight; for by striking with a hammer on the head of the cutter or chisel HH, all the movements are set at work; and by repeating the stroke with the hammer, the files on one side will at length be cut; then they must be turned, and the operation repeated for cutting on the other side.  It is needless to enlarge much on the utility or extent of this machine; for, on an examination, it will appear to persons of but indifferent mechanical skill, that it may be made to work by water as well as by hand, to cut course or fine, large or small, files, or any number at a time; but it may be more particularly useful for cutting very fine small files for watchmakers; as they may be executed by this machine with the greatest equality and nicety imaginable.  As to the materials and dimensions of the several parts of this machine, they are left to the judgment and skill of the artist who may have occasion to make one; only observing, that the whole should be capable of bearing a good deal of violence.