The Optical Magic Lantern Journal (June 1898)

92 The Optical Magic Lantern Journal and Photographic Enlarger. d driven by the main wheel n” on the driving shaft o. The movement being such that when the film is stationary the objective is uncovered, : and when the film is moving the objective is closed. In order to prevent the objective c from being moved by the vibration of the apparatus when working, it is clamped by a tightening collar B' and screw B”. No. 13642 of 1896. Another cinematographic machine, the movement of the film being a step by step motion, is shown in the accompanying figures XIII. and XIV., and a rotating shutter is employed which is constructed in such a way as to give a drop shutter effect in working. The construction of this shutter is shown in Fig. XIII., B is the shutter of a segmental shape, that is to say, with one edge straight and the opposite side curved, but with the one end cut across instead of coming to a point as in the case of the other Fig. XIV. Fig. XIII. end of the ‘shutter, thus the shutter, although revolving, has all the advantages of a drop -shutter; when it starts to cover the film opening, the lower edge J of the shutter is approximately straight across the opening, and when the shutter leaves the opening the end 6' is also straight across the opening so as to give a complete exposure of the picture and a complete cut off of the picture during the instant that the following picture is appearing. The shutter B is attached to the end of the arm 6°, which is secured to the disc E keyed on the horizontal shaft f. The said shaft f is mounted eccentrically on a disc G at the otber side of the plate a, which disc is carried upon the horizontal shaft Gg! to which the rotating gear is connected. The shaft f of the shutter arm is set one-half inch out of line of the main shaft Gc’, and is provided with a triangular shaped tappet H, and the arrangement is such that as the disc @ is rotated the shutter is simultaneously rotated, and the film gripping and feeding mechanism likewise. The film is perforated at both sides in the ordinary way, and to grip and feed the film two pairs of horizontal pins J are used to correspond with the perforations at each side of the film; the pins are fixed at right angles to a bar j which is moved to and from the film by means of the rotating disc kx. The pins 3 pass through the joggling arm x’, which is moved rapidly up and down through the medium of the triangular tappet H, and is guided by the pin j’ which works through a hole in the guide bar 7* and is bracketed to the side of the tappet moved arm. The disc K rotates between two pins L, and by virtue of a bulge & on the edge of the rotating disc the pins are caused to vibrate in and out of the perforations in the film. The arrangemeut is such that when the bulge & of the disc comes in contact with the disc pins L on the downward motion of the disc, it puts the film pins out of gear by drawing them back. Meantime the motion of the tappet is carrying the forked arm upwards for the purpose of enabling the pins to be ready to take another grip of the film. On the fiat part of the disc cam coming into action with the disc pins the gripping pins are put into action, and when the bulge of the disc comes round again the film pins are withdrawn from out of the perforations. No. 28799 of 1896. How to Select a View. By E. DUNMORE. aCony Te HERE is little doubt but that the V4 iS success of the landscape photographer hinges mainly on his ability to select a suitable subject, for no matter how excellently well the negative may be made, or however skilfully it be may printed, a wrong or uninteresting subject will afford little or no pleasure to anyone; this especially applies to lantern slides when the positive is exhibited on an enlarged scale, which emphasises the wrongness and tires with its utter commonplace effect. Very many who take up camera work and start out for a day’s photographic exercise and amusement, feel somewhat non‘plussed at the very beginning by their inability to find anything to photograph that comes up ; to their ideas of a picture. ‘‘ So-and-so