The Art of projection and complete magic lantern ... - Yesterday Image

24which is passed over the rod, and held in position by the aid of a thumbscrew being clamped to the rod. When the jet has been lighted andthe desired light obtained, place a picture in the slide holder, and focussame up sharply ; this done, remove the slide, as the condition of thedisc has to be observed, and proceed to adjust the jet for the bestillumination. The easiest way to hold a jet, when adjusting thelight, is to place the first and second fingers of the left hand under thejet by the pillar, and steady with the thumb. With the right hand holdthe thumb screw, raising the jet up and down on the rod, watching thescreen at the same time, and moving same to the left and right, givinglateral .and longitudinal movement, until the jet is in the exact centre ofcondenser, then clamp same to the rod, by aid of the thumb screw,giving a little extra pressure to ensure it holding firmly. The tray withjet attached should now be moved in or out as the case may require, thismovement affects the edges of the disc. The diagram below will helpthe novice in adjusting the limelight for the first time or two.Fig. 17.A. Jet not low enough on the rod. B. Jet too low down.C. Jet too close to condenser. D. Jet not near enough. £. As a disc should appear.