I'liUKIl TR.IXSMISSIOX (U//v' lll.iriloM I.I MS l«»i 



ni:SCRII'TIO\ OV .\l'l'ARAH.S 



Mfchanical A rraii'^emciits 



Till' i-ssi-iiti.il p.irls 1)1' ilu- iiu'cli.iiiiMn iisimI for mi.iiini; .md .idv. lur- 

 ing the cylinder at the sending statiDii, and for holding tin- |)liolo- 

 tlfctric ci'll and the aniplif\inj; and niodiilatin); sNsttni are shown 

 in the photograph, Fig. 7. At the extreme left is llie |)hoiiic wlieil 

 impulse motor, which drives the lead screw through a spiral gear. 



Kig. 7 —Sending end apparatus showing motor, tilni carriage, optical system and 

 amplifier modulator 



The spiral gear ordinariK- turns free of the lead screw, hut may be 

 engaged with it by a spring clutch. The lamp housing, whic h pro- 

 \ides the illumination for the photoelectric cell, is in the foreground 

 at the center of the photograph. The photoelectric cell is in a 

 cylindrical case at the left enti of the large box shown on the track 

 and projects into the picture cylinder on which a film is in process 

 of being clamped. The amplifier and modulator system is carried in 

 the large box to the right, which is mounted on cushion supports to 

 eliminate disturbances due to vibration. 



