Pieces Joined At Angles Other Than Right Angles. In figs. 379 and 380 various methods are .llustrated. The joints here illustrated may be strengthened by adding what are called "blockings," as a a, in figs. 380 and 381; these in place of having the sharp "arris" or corner, as at b in fig. 380, may be formed as shown by the dotted lines in fig. 381. For joining pieces at right angles -'dovetail" joining is used for fine work in joinery. Fig 382 illustrates what is known as the "common dovetail," in which one piece has " tenons," "dovetails," or "pins," formed dovetail fashion, as at a, these going into dovetail shaped mortices b; the projecting parts c, formed by these, going into the corresponding hollow parts d. In this form of joint the ends of the tenons or pins are seen at both sides of the pieces to be joined, as a a show the ends of tenons a a a at the return side of the edge b c. In what is called "lap-joint dovetail" the ends of the tenons show only at one side, this is effected by cutting the tenon or pin of one piece short off, and in corresponding proportion making the mortice in the other piece shallower, so that it does not go completely through; this is illustrated in fig. 383, the upper drawing showing the mortice used in " common dovetailing," the lower, the mortice b stopping short at c; this is further illustrated in fig. 384, a b being the common mode, showing the ends ab of tenons at both sides; d the "lap joint," showing the tenon at one side only; c shows the inside of a mortice. In "mitre" dovetailing, the tenons show on neither side of the pieces to be joined, the whole being concealed; this is illustrated in fig. 385, the tenons and mortices both being shortened and stopping at the flat pieces a a, which are mitre-jointed at the corners, so that the joint shows but a fine line at each corner.