Chapter IV: , Section 45, with a bit slightly smaller than the width of

the mortise. (3) The sides of the mortise are next pared to the gage and knife lines, beginning at the auger holes and working with thin slices toward the lines. This method requires care and patience in order to get the sides of the mortise cut square to the surface. It is especially well adapted to large mortises from which much wood is to be removed.

=96. Directions for Cutting Mortise.=--_Second Method_: (1) Clamp the piece which is to be mortised firmly to the bench top, using a hand clamp. Fig. 163 shows a little device called a mortise grip. Tighten the vise screw and tap the grip with the mallet until it holds the piece solidly. (2) Select a chisel of a width equal to that desired for the mortise. Stand well back of the mortise at one end or the other so as to be able to sight the chisel plumb with reference to the sides of the mortise. (3) Begin the cutting in the center of the mortise. Make the first cut with the bevel of the chisel toward you; reverse the bevel and cut out the wedge-shaped piece, w, Fig. 164. (4) Continue cutting in this manner until the proper depth has been attained, making the opening no larger at the surface than is necessary. (5) Set the chisel in a vertical position, bevel towards you, begin at the center and, taking thin slices, cut toward the farther end. Drive the chisel the full depth of the mortise each time, then pull the handle towards you to break the chip from the sides of the mortise. Cut to within one-eighth of an inch of the end of the mortise. (6) Reverse the piece, or your position, and cut in a similar manner to within one-eighth of an inch of the second end. (7) With the bevel side of the chisel next the end of the mortise pry out the chips once or twice as the cutting proceeds. (8) Chisel the ends to the knife lines, carefully sighting the chisel for the two directions. Fig. 165 suggests the order.

=97. Miter Joint.=--The miter joint is subject to various modifications. In the plain miter, Fig. 166, the ends or edges abut. They are usually fastened with glue or nails or both. The most common form of the plain miter is that in which the slope is at an angle of forty-five degrees to the edge or side.

=98. Directions for Miter Joint.=--(1) Lay off the slopes (see Chapter I, Section 4). (2) Cut and fit the parts. To fit and fasten four miter joints, such as are found in a picture frame, is no easy task. Special miter boxes are made for this purpose which make such work comparatively easy. (3) Fig. 167 shows the manner of applying the hand clamps to a simple miter joint. When a joint is to be nailed, drive the nail thru one piece until its point projects slightly. Place the second piece in the vise to hold it firmly. Hold the first piece so that its end projects somewhat over and beyond that of the second; the nailing will tend to bring it to its proper position, Fig. 168. If a nail is driven thru from the other direction, care must be taken to so place it that it will not strike the first, or a split join will result.

=99. Dovetail Joint.=--Dovetailed joints are so named from the shape of the pieces which make the joint. Fig. 169 shows a thru multiple dovetail commonly used in fastening the corners of tool boxes. In hand made dovetails, the tenons are very narrow and the mortises wide, while in machine made dovetails, tenons and mortises are of equal width. Mechanics lay out the tenons without measurement, depending upon the eye unaided to give the proper size and shape. Sometimes dovetails are laid out to exact shape and size, the tenons being marked on both sides and ends. The mortises are marked with trysquare and bevel after one side of each has been marked by superimposing the tenons. In some kinds of dovetailing, such as the half-blind dovetail, the mortises are made first and the tenons marked out from them by superposition.

=100. Directions for Dovetail Joint.=--(1) Square lines around each end to locate the inner ends of the mortises and tenons. These lines will be at a distance from the ends equal to the respective thicknesses of the pieces. (2) Determine the number of tenons wanted and square center lines across the end of the member which is to have the tenons. Place these center lines so that the intervening spaces shall be equal. (3) Measure along an arris and mark on either side of these center lines one-half of the desired width of the tenon. In fine hand made dovetails, the usual width for the narrow edge of tenon is scarcely more than one-sixteenth of an inch--the width of a narrow saw kerf. (4) Set the bevel for the amount of flare desired. Fig. 170 shows measurements which may be used in setting the bevel. A flare stick may be made of thin wood and used instead of a bevel if desired, Fig. 170. (5) Mark the flares on either side of the center lines. Place the bevel so that the wide side of the tenon shall be formed on the face side of the piece. (6) Carry these lines back on each side of the piece as far as the lines previously drawn across these sides. (7) With a fine tenon saw rip accurately to the lines. Cut the kerfs out of the mortises, not out of the tenons. (8) Chisel out the mortises formed between the tenons and trim up any irregularities in the tenons. (9) Set the tenons on end on the face side of the second member, with the face side just touching the cross line placed on the second member, Fig. 171, and mark along the sides of the tenons. (10) Square lines across the end to correspond with the lines just drawn. (11) Saw accurately to the lines, cutting the kerfs out of the mortises, not the tails. Chisel out the mortises for the tenons, Fig. 172. (12) Fit the parts together.