Page:Popular Science Monthly Volume 89.djvu/749

 I'o/iiihir Scirnrr Moiit/ili/

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���A worm gear connects the shaft of the handle of the projector-machine with the steel pegs of the cue-machine

��WHE.E.L RLVOLVES ONCt LVERY 15 T-

REVOLUTiON or

OPERATORS -','■■,->■ HANJDLE iJ)LI

��sentimental. The necessary orchestral accompaniment will be pianissimo. This shading is expressed, according to the index card, in column No. i. By that time the control device on the projector has moved the cylinder a short distance, so that the pencil mark will be slightly lower than the first one. This operation is repeated until the film has run its course. The cylinder has made one complete revolution.

In order that the record of musical shadings marked in pencil dots on the pajier record may be indicated by the Hashing of cues in their proper order, the pencil dots must be duplicated on the left hand side of the cylinder by means of steel pegs fitted into the lines of holes. There are fifteen of these lines of holes correspontling with the fifteen columns on the paper record.

The first scene, we remember, called for music at fortissimo, and it was indicated by a pencil mark in column No. 2. Accordingly, a metal peg is inserted, parallel with the mark, in the second line of holes. When all of the pegs, corresponding with* the pencil marks, ha\"c been inserted, and the cylinder is again revoked, the cue signals in the reel glass box flash in their prop- er order. The signals are caused to flash by the metal pegs which press small springs upward, causing electric connections to be made, cleli\er- ing current to the corresponding signal lights.

��As the film is reeled through the projection-machine an electrical contact is made with the cue-machine at every fifteenth revolution. The moving steel pegs push up contact springs and the prop- er signal is flashed to the orchestra. Wh-?n all the reels have be?n shown, the cylinder in the orchestra pit will have made one complete revolution

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