Quoins.—The wedges used to tighten or lock-up a form of type. E. G. See Figs. [155] and [156].
Rabbet.—A groove or hollow cut in a piece of work, generally for the purpose of joining it with some other material. E. G. The sides of the bow and stern pieces of the Canvas Canoe described in Chapter XV are rabbeted so the ribbands and the edge of the canvas will fit in them (see Figs. [200] and [202], Chapter XV).
Radius.—The distance from the centre of a circle to any point upon its circumference. It equals one-half of the length of the diameter.
Rasp.—A file with coarse teeth, used for working upon wood.
Recess.—A niche in a wall; a space or opening formed by the wall setting in a little way.
Reënforce.—To strengthen; to supply additional strength with strips or braces.
Ridge.—An edge of a roof formed by the meeting of two sloping surfaces. The top edge of a peaked roof. E. G. See [Fig. 192], Chapter XIV.
Ridge-boards.—The boards fastened along the ridge of a roof to cover the joint. E. G. See [Fig. 192], Chapter XIV.
Right Angle.—An angle of ninety degrees. At Right Angles.—So as to form a right angle.
Rubbing Down.—Bringing to a smooth surface by rubbing with sand-paper, emery-paper, or pumice stone.