Cross-Section of Bowling Bed Showing Steel.

Clamp other end of the strip is continued by adding other strips the full length of the bed. When these have been carefully squared to the exact direction the alley is to run, they are fastened to the leveling strips.

The next strip, also of maple, is tongued into the lower one, but its continuous length extends only about five feet beyond the foul line, or about eighteen feet from the approach end.

A bowling bed cannot be laid as an ordinary floor. It is built upon its side and when finished resembles a wooden wall about seventy-five feet long four inches high and three inches wide.

The approach end of the bed, approximately eighteen feet long, is constructed of maple, with each alternate strip of the 3 x 1-inch bed stock about eighteen inches shorter. The pit end of the bed is similarly constructed for a distance of about six feet. The space between is filled in with the pine strips of the same dimensions, and the alternate long and short strips at the inner ends of the approach and pit ends form mortices into which the pine dovetails.

The wear on the bed occurs where the bowler walks and drops the ball and where the ball strikes the pins; hence the hard maple. The interior is filled with pine, which is softer, because it retains a higher polish and prevents the rolling ball from bumping; thus throwing it from its proper course.

Pit End Section of Bowling Alleys.

The bed is thus built up for its continuous length, strip by strip, the tongue of one strip fitting into the groove of the other, and both nailed firmly together, until the proper width (while being built, the height) is attained. When the bed is finished, the strips are clamped with steel clamps, the turned-up ends of which firmly grip the sides of the bed, thus preventing warping or spreading. While the bed is still in this upright position, a one-inch slot is cut across where the foul line is to rest, and holes are bored through the bed. A black composition strip, i. e., the "foul-line," is inserted in the slot and bolted through the holes to the bottom of the bed.

At the pit end, circular slots are cut and holes bored for the purpose of countersinking and fastening the "pin spots." The latter are of the same substance as the foul-line and all are sunk flush with the surface of the bed.

This - clamping and fastening - explains the necessity for building the bed on its side.

It is now ready to be placed into position. It is merely toppled over, face side upward, clamped side underneath. So exact has it been built, according to specifications and alignment, and the mass is so heavy, that the dead weight makes it lie where it falls and only the slightest adjustment is necessary.

The height of the leveling strips, plus the height of the bed, lift its surface about six inches from the foundation floor. At the pins end of the bed, this forms one of the sides and the bottom of the pit. The bottom is floored with maple and covered with a specially prepared pit mat, durable, yet soft, so as not to damage the balls and pins falling upon it. The back and sides of the pit are formed by the kick-backs, braces and cushion.

After the kick-backs are placed in position, the gutters are laid, and then the return chute railway is laid, between and slightly above them. At the approach end of the bed the newel post is firmly fastened to the foundation, and the floor that is laid above the latter and flush with the surface of the bed serves to brace the post, making it immovable. The curved end of the chute and the receiver are then added.

The bed is then planed its entire length, sandpapered, shellaced and polished. The remainder of the woodwork is finished in its natural color except the gutters, which are stained mahogany and shellaced. They are thus stained, not only for artistic effect, but to clearly define the outer edges of the bed - a matter of great importance to the bowler when trying to knock down the two outer pins in the third row.

In making the pins, the best selected logs are sawed into blocks about 2x1 feet. These are placed in a lathe and gouged out, forming the pin in the rough. They are next turned down to size and selected for quality and weight, after which they are kiln dried and receive a final turning to perfect their formation, then smoothed and finished. The Backus pin-setter is almost human in its operation. The old way was to hire boys to set up the pins on the spots and return the ball via the return chute. The pin-setter relieves the boy of the major and most time-consuming part of this work. A frame holding the machine is set up over the spots. It is placed so high that it does not interfere with either the flying pins or the rolling balls.

As the pins are knocked off into the gutters, or the pit, the pin boy picks them up and lays them flat on their sides into the pockets at the top of the machine. When a "frame" is rolled those pins standing on the alley remain there and the machine is lowered by a balance weight controlled by a lever. As it descends the pins are automatically set on end, and when they rest on the spots on the alley the machine releases them and springs up to its original position.

Wooden balls for bowling were never satisfactory. They wore out too easily and never retained perfect rotundity. Fortunes were spent in experimenting with other materials until at last the famous "mineralite" ball was perfected.

Backus Automatic Pin Setters.

Its composition is a trade secret, but its chief ingredient is rubber.

First the composition is rolled into sheets. These are then molded and later vulcanized, being subject to terrific pressure. The balls are then smoothed and polished.

As it is impossible to make a perfectly round ball and have the weight equally distributed, the ball can not roll true; an ingenious device overcomes the difficulty. The ball is set in a basin of mercury, where it floats. Naturally, the heavier side of the ball swings to the bottom. On the top, diametrically opposite to the center of weight, a chalk mark is placed on the ball and it is then lifted out of the mercury.

Diametrically opposite to the chalk mark a small hole is punched into the ball to indicate the weightiest point. Directly beneath this is stamped the trademark of the firm.

Having ascertained the proper distance apart the finger holes are to be bored, the ball is weighed to determine the excess of its proposed weight when finished.

The holes are then machine bored at the respective points, sufficiently deep to reduce the weight to exact specifications.