square, or inclined to any number of degrees, a tool called a square is used, and in the latter instance, a bevel is set to the angle; when any piece is to be reduced to a parallel breadth or thickness, an instrument, called a gauge, formed of a square piece with a mortise, having a sliding bar, called a stem, running through it at right angles, and furnished with a tooth, projecting a little from the surface, is used; so that when the stock of the gauge is applied to the vertical side or edge of the piece, with the toothed side of the stem upon the horizontal surface, and is pushed and drawn alternately backwards and forwards by the workman, the tooth will make an incision from the surface into the wood, at a parallel distance from the edge to which the stock part is applied.

When a mortise is to be made in a piece of wood, the gauge used has two teeth. The construction of this gauge is the same as that before described, except that the tooth nearest the stock moves by means of a longitudinal slider in the stem, which is to be set at a distance from the other tooth, as occasion may require.

If a piece of wood is to be sawn across the fibres, a flat piece of wood, which has two projecting knobs, on opposite sides, one at each end, called a side-hook, is used, to keep the piece which has to undergo the operation of the saw steady; the knob at one end presses against the piece, while that at the other end is hooked to the bench. Two of these are necessary when the pieces are long.

When a piece of wood is required to be cut to a mitre, that is, to half a right angle, joiners use a trunk of wood with three sides, like a box that has neither ends nor top, the sides and bottom being parallel pieces, and the sides of equal height. Through each of the opposite sides, in a plane per pendicular to the bottom, and at the oblique angles of 45° and 135° with the planes of the sides, a kerf is cut; and another kerf is made with its plane at right angles to the two former. Into this trunk, termed a mitre-box, the piece to be cut is put, and the saw, guided by the kerfs, cuts the wood to the angle required.

In making a straight surface, a strip of wood called a straight-edge, which has one of its edges perfectly straight, is frequently applied, to detect the irregularities, and the piece is accordingly planed with the trying plane until the surface coincides with the straight-edge.

To ascertain if the surface of a piece of wood be in one plane, the joiner takes two slips of wood, each straightened

on one edge, with the opposite edge parallel, and both pieces of the same height, and places them one at each end, across the board under operation; he then looks in the longitudinal direction of the board over the upper edges of the slips, and if the two edges and his eye be not in one plane, the upper parts are planed down until the piece is said to be out of wind, and the same term is applied to the slips, which are called winding-sticks. The operation of making the edge of a board straight is called shooting; and the edge so made is said to be shot.

From what has been here said of the application of the principal tools used by the joiner, we consider any further account of the primary processes unnecessary; we shall, therefore, proceed to lay before the reader the best methods in use of effecting some of the more difficult and particular operations.

To construct the surface of a portion of a cylinder with wood, when the fibres are at right angles to the axis of the cylinder, such as may be used in a circular dado, or the soffits of windows.

If the dimension of the cylindric surface, parallel to the axis, be not broader than a plank or board, this may be done by gluing several thicknesses of veneer upon each other; the first upon a mould, or upon brackets, with their edges in the surface of the proposed cylinder, parallel to its axis. This may be effected by means of two sets of brackets fastened to a board, one convex and of the curve intended, and the other concave of the curve of the exterior of the whole thickness of veneers, or somewhat larger; this last bracket is then applied on the top of the veneers and fastened to the other bracket, and the veneers are then forced together by means of wedges between the concave bracket and the veneer. If this operation be carefully done and the glue properly dried, the wedges may be slackened and the work will stand well, but it must be observed, that, as the wood has a natural tendency to unbend itself, the curved surface, upon which it is glued, should be rather quicker than that intended to be made.

A second plan is to form a templet or cradle to the surface intended, and lay a veneer upon it; then to glue a number of blocks of wood upon its back, closely fitted to its surface, and the other joints to each other, the fibres of the veneer being parallel to those of the blocks.

A third method is to make a cradle and place the veneer upon it, confining one end lay the glue between the

veneers with a brush, and fix a bridle across, confining its ends either by nails or by screws; open the veneers again, put glue a second time between each, and fix another bridle across them; and in this manner proceed to the other extremity.

A fourth plan is to cut a number of equidistant grooves across the back of the board, at right angles to its edges, leaving only a small thickness towards the face; then to bend this round a cradle with the grooves outwards, and fill the grooves with strips of wood, which, after the glue is quite dry, must be planed down level with the surface of the board. This may be stiffened by gluing strong canvass on the back.

To bend a board so as to form the frustum of a cone, or any segmental portion of the frustum of a cone, as the soffit of the head of an aperture.

When the envelope of the covering is found by the rule laid down under the article Masonry, page 542, and the mould is made with a thin piece of board, cut out the board intended to be bent, and run a number of saw kerfs, or grooves made by a plane, (which are preferable,) equidistant from each other, and tending to the centre, and having fixed it to a templet, made to the surface of a cone, finish it in the manner shown in the last method, for a cylinder.

To glue up the shaft of a column, supposing it to be the frustum of a cone.

Prepare as many staves as the circumference may require, and let the joints of each be so managed as to fall in the fillets, which disposition will be stronger than if they were to fall in the middle of the flutes. Suppose eight pieces to be sufficient to constitute the shaft of a column: describe a circle to the diameter of each end; about each circle describe an octagon; from the concourse of each angle draw a line to the centre, then draw an interior concentric octagon, with each side parallel to the respective sides of the corresponding one, and the distance between these two octagons equal to the thickness of the staves; and thus the section of the staves will be found at each end, and consequently, the bevels will be obtained throughout the whole length. In order to join the column, glue two pieces together, and when quite dry, glue in blockings to strengthen them; join a third piece to the former two, and secure it also by blockings. In this manner proceed to the last piece but one. In fixing the last piece, the blockings must be glued to the adjacent staves;

and their surfaces, on which the last stave is intended to rest, must be all in the same plane, that its back may rest firmly upon them. In closing up the remaining space, the part of the column that is glued together should be kept from spreading by confining it in a kind of cramp, or cradle, while driving the remaining stave to close the joints.

Instead of the foregoing mode, some joiners glue up the columns in halves and then glue them together. When an iron core is necessary to support a floor or roof, the column must necessarily be glued up in halves; in which case the two halves are to be dowelled together, and the joints filled with white-lead. Instead of a cramp, a rope is used, twisted by means of a lever. In bringing the two halves together, the percussive force of the mallet must be applied upon the middle of the surface of one half, while an assistant holds something steady against the middle of the other, that the opposition may be equal, and by this means the surfaces will be brought into contact, and form the joint as desired. In this operation pieces of wood ought to be inserted between the column and the rope.

Boards can be connected together at any given angle, either by pins or nails, mortise and tenon, or by indenting them together.

This last mode, from the sections of the hollows and projecting parts being formed like a dove's tail, is called dove-tailing.

There are three sorts of dovetailing; viz. common, lap, and mitre. Common dovetailing shews the form of the projecting parts, as well as of the excavations made to receive them; lap dovetailing conceals the dovetail, but shews the thickness of the lap on the return side; and mitre dovetailing conceals the dovetail and shews only a mitre on the edges of the planes at the surface of the concourse; that is, the edges in the same plane, the seam or join being in the concourse of the two faces, making the given angle with each other.

Concealed dovetailing is particularly useful where the faces of the boards are intended to form a saliant angle; but when the faces form a re-entrant angle, common dovetailing is preferable.

There is another simple and expeditious manner of connecting the ends of boards together where the faces form a re-entrant, or internal angle, by means of a groove in the one, and a tongue in the other; and if the pieces be pre