Four hooks are then fastened to the frame, underneath the table, near the corner legs. These are termed bridge hooks and are for the purpose of having the cue-bridge ready of access for the players when necessary. The table is thus completed for playing use. There are ingenious devices, termed the “return gutters” and convertible rails, which are worthy of description. In tables thus equipped, the base of the pocket is opened--a stiff leather, funnel-shaped contrivance being substituted for the woolen or open leather pocket. This funnel opening leads into a wooden canal or gutter, the main stem of which runs on an incline the length of the table underneath. From this center gutter debouches branch to each of the pockets. The gutters are lined with rubber, to render noiseless the balls as they roll from the pocket openings into and along the gutters, at the lowest point of which--the head of the table--they fall into the “receiver.” The latter is a specially designed box, felt lined, with sufficient capacity to contain the fifteen balls used in the pocket game. The gutter return is a great convenience in collecting the balls to rack them for a new game. Carom tables have no pockets. Carom and pocket billiards are so different that either they must be played on separate tables, or else the rails are so constructed as to be interchangeable. The billiard expert is not satisfied unless the whole rail is changed. This is done by building the table without the regular rails, and by having a separate set of rails for each game, which are held in position by clamps and quickly interchanged. They conform to the general design and decoration of the table. Another method is merely to change the cushions. The back of the rubber is reinforced by a wood strip, into which are placed metal sockets. Bolts or ratchets are inserted through the rail, and clamp the cushion to the wall of the rail. The convertible rails, however, because of their rigidity, are more desirable than the convertible cushions. The cheapest and most unsatisfactory device is known as pocket plugs. On a permanently constructed pocket table, right-angled plugs of the rubber cushion are screwed to the corner pocket irons and straight sections are screwed to the side pocket irons. These, however, never perfectly fit at the cushion joints, consequently carom play at those points is out of the question. [Illustration: A MODERN HIGH-CLASS POCKET BILLIARD TABLE] Cheap cues are made in one continuous piece; or a special piece for the “butt” and one for the shaft of the cue. The “butt” and body are dovetailed together.