Page:Popular Science Monthly Volume 89.djvu/748

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��Pnpuldr Srinirr Moiitlili/

���The cylinder is divided into two parts. A nilcd strip of pnpcr encircles one side and fifteen lines of smnll holes the other. The lender makes his inflection marks on the paper at the first rehearsal

��wliuh is placed in the center of tlic orchestra. The current actuates an electromagnet, the plunger of which catches in small notches in the left- hand rim of the cylinder and turns il a short distance. Even- time the contact at the I>rojcction machine is made, the magnet turns the cylinder a distance equal to one of the notches. The apparatus is so arranged that when the five or six reels of film which constitute the ph - have been shown on the screen, the cxlinder in the orciiestra pit has matie, in a succession of short steps, one complete re\dlution. The face of this cylinder which is made from an ordinary steel imlley, isdi\ided into two parts, as shown. Fifteen parallel lines of equalh' spaced small holes, are bored around one side, while a strip of ruled jiaper encircles the other. W'lun the orchestra leader \-iews the film for the lirsl lime he makes small (lencil dots on the paper c\ Under, as the drum slowK' re\ol\-es. He has fifteen ruled olT columns in which to place dots, each column being allotted to a certain musical cue. Let us say, for illustration, that the opening scene of the film calls for loud, exciting music. A stationary index-card, fasten- ed on a fr.ime al)ove the cyliniler, informs him liiat fortissimo, or ff, shall be indicated in column No. 2 on the paper record. He makes a pencil mark in that space. As the film progresses its dr.imalic (|ii.ilil\ changes, let u> sa\\ to

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