Richardson's handbook of projection (1930)

1064 HANDBOOK OF PROJECTION FOR the face of the slit lens tube — parallel with the film. See to it that it is so. Having inserted the lamp into its socket, shove the bracket into place, make certain that the lamp filament is parallel with the face of the lens tube, as above set forth, and tighten clamp screw D. Next, loosen clamp screw I, Fig. 395, by means of adjusting screw X, raise or lower the lamp until the slit in the lens tube is in the center, up and down, of the light beam. Tighten clamp screw I. Next loosen clamp screw G and, using adjusting screw C, move lamp until the slit is in the center of the light beam sidewise. Tighten clamp screw G. You now have the exciting lamp properly located up and down and sidewise, but it still remains to move it backward and forward until the slit is correctly focused upon the sound band, which may be done by means of adjusting screw H, Fig. 395, which is clamped by means of screw E. If all this has been properly done, the slit image should be sharp and brilliant and in proper location upon the film sound band, but this latter should be tested by means already described, using negative film. NOTE. — This is not designed to take the place of the instructions contained in your operating instruction book. I have set it forth so that those thousands who are not yet handling Western Electric sound apparatus may get some understanding of the apparatus and its correct adjustment. I strongly recommend to you that you read and study the operating instruction book issued to you by Electrical Research Products and RCA Photophone, De Forest Phonofilm, Powers Cinephone and