adapted for sharpening moulding irons are fitted; at the opposite end of the spindle is an emery hone for finishing purposes. The water necessary is supplied by means of a small pump, worked from the countershaft shown at the back of the machine. Several machines were shown at the recent exhibition in Paris by

FIG. 37.-HANDYSIDE'S PATENT TOOL GRINDER.

F. Arbey on which were fitted small revolving emery discs, arranged to sharpen the plane irons without removing them from their blocks. In the use of emery for this purpose very great care must be observed, or the cutting edge of the iron will be made too hard, and consequently chip in the working.

For sharpening long plane-irons a grinding-rest, with lateral and transverse movement, should be attached to the grindstone; the iron should be held in a frame arranged to set to any desired bevel, by which means the longest irons can without difficulty be ground perfectly true.

It is very necessary that the grindstone itself should be in good order, and true on the face. For many years, when the stone became untrue, it was the custom to turn it up with a pointed steel tool. This plan, however, is very wasteful, and in many establishments has given place to handy little apparatus for dressing up grindstones, patented by a Mr. Brunton some five years since. It consists of a steel disc bevelled to a cutting edge on one side, and keyed to a spindle which revolves in a socket attached to a plate. The cutting disc and plate are made to traverse across the face of the stone by a hand wheel and screw. The disc is fixed at an angle to the stone, and is pressed against it, the stone thus causing the disc to revolve at a speed on its cuting edge equal to that of the stone. Any degree of feed can be put on the cutting disc, which quickly removes inequalities, leaving the face of the stone perfectly true, causing the smallest amount of waste to the stone and effecting a considerable saving in time.

For grinding moulding irons some four Bilston or other sandstone grindstones, of some 18 inches diameter, should be mounted on a spindle revolving in a trough. These should be turned up to fit the outlines of the various moulding irons. In addition to these four stones, two other fine grit stones are usually attached, to give the irons a fine cutting edge after they have been reduced on the shaping stones.

CHAPTER XXV.

HAND-POWER MACHINES.

ONE of the most general operations in joinery is that of mortising, and there are few but the very smallest establishments that cannot employ a machine driven either by steam or hand economically. It is a matter of some doubt when a machine for mortising was first made in this country. Probably rotary machines driven by water power were in use at the end of the last century. However that may be, Bentham in his specifications in 1793 distinctly claims both reciprocating and rotary machines; and it seems that he, in connection with his brother, Jeremy Bentham, was commissioned some few years later by the Government to fit up several of the dockyards with machinery, amongst which mortising machines are mentioned. In the first thirty years of this century little or no progress was made, and very little appears to have been done in manufacturing machines for sale. Even in the year 1848 the manufacture was confined to a very few firms in this country, amongst which we may name the following as the most important :-Worssam, London; Horn, London; Powis, James, and Co., London; Robinson, Rochdale; Furness, Liverpool; McDowall, Johnstone; Forrest and Barr, Glasgow; and most of these

FIG. 38. HAND-POWER MORTISING AND BORING MACHINE.

When we compare

made only on a very small scale. the large establishments now in operation, and the great range of machines turned out, we cannot but admit that sawmill engineers have, to say the least, kept pace with any other branch of engineering.

A mortising machine worked by the foot was invented by Mr. John Mortimer, of Aberdeen, in the year 1847; and the hand-power lever mortising machine was introduced into this country from America by Mr. Coulson, of York, about the same time.

The mortising and boring machine we illustrate herewith (fig. 38), although somewhat modernised, is substantially the same as one brought out by Messrs. Wilson and Lewis, for the firm of Powis, James, & Co., in the year 1852, and for the combination of the operations of mortising, tenoning, and boring in one machine letters patent were granted to them. The illustration does not show the tenoning arrangement, which, however, is easily added. As a strong, well-made machine it compares favourably in the ratio of six to one against hand labour with chisel and mallet; the wonder is, in these high-pressure days of cheap production, that they are not more universally used than they are, as they would pay a handsome interest on the amount invested if they were idle one-half of the year.

The action of the machine is easily understood. Motion is given to the chisel by a counterbalanced forked lever (worked by one or both hands), which is connected with a gun-metal cross-head at the top of the vertical spindle by two wrought-iron double eye-pieces. The wood to be mortised is placed on a table immediately beneath the chisel. This table can be worked by the large hand-wheel, which is perhaps the most