The Optical Magic Lantern Journal (June 1899)

72 The Optical Magic Lantern Journal and Photographic Enlarger. condensers, and the combination gives a splendid disc at long range. When in the Albert Hall, London, Mr. Sambridge used his lantern a distance of 185 feet from the screen. A characteristic of the ‘‘ Guinness Missionary Lantern Lectures” is the comparative smallness of the picture on the screen. ‘‘ To some extent merely a matter of taste,’ said Mr. Sambridge when asked the reason, ‘‘but it is also a question of ‘quality v. quantity.’ In too many cases the picture is made uselessly large, and thus the sparkle and depth of a smaller disc is lost. It is like spreading your pat of butter over a large or a small slice of bread!’’ After his unique experience with regard to hitches— or ratber the absence of them—we were not surprised to learn that Mr. Sambridge considers smoothness as the most desirable qualitication of a lantern exhibition. Everything has its proper place in one or other of the packing cases, and on arrival at the hall a delightful mixture of humour and politeness soon wins the hearts of porter, janitor, and the message boy as well. No bustle, no hurry, an hour or so of steady systematic work and all is in position, a large soft cloth is thrown over the triple and Mr. Sambridge goes off to tea. About an hour before the doors are to be opened he returns, slips the cloth covering from the lantern and proceeds with the focusing and registration. When this is done to a nicety, the gases are turned off, fresh limes put on the jets and the operator disappears. Then the doors are opened and the hall soon fills. At five minutes to the hour he slips in beside his triple bringing the slides with him. A general examination shows everything to be in order, and when Dr. Harry Guinness steps on to the platform “lighting up” is at once proceeded with. There is no splutter or hiss from the jets, not a noise from the lantern to break the silence, and when the hall lights are quite turned off, the top lens cap is removed and the first picture is revealed. On they go, slide after slide in perfect coincidence, all without the least signal from the lecturer to the operator. Focusing is done imperceptibly, and Mr. Sambridge called attention to the very small movement necessary to regain perfect definition. Some lanternists have been known to, as it were, jump at the lens rack-pinion and turn it an inch one way and then an inch the other in their anxiety to rectify a fault, which only requires the smallest touch of the screw, but there is nothing of this kind with Mr. Sambridge’s operating. How Cinematographic Machines Work.—No. IX. By MAGNET. A, HE following is an account of an invention of Herman Casler, which contains many features of interest, especially in many of the small = details which go to make up the 2e) efficient working of the machine :— oe Firstly, a web feeding apparatus ; vw secondly, so arranging the parts as to cause the main feeding and take-up mechanism to feed, forward, and take up the web at the game speed, so as to avoid either the accumulation of loose film in the machine or drawing the iiln too tight; thirdly, an intermittently acting auxiliary feeding mechanism; fourthly, a means for compensating for slipping or shrinkage of the film, and for varying the length of the film fed forward each time the auxiliary feeding mechanism acts; fifthly, compensating automatically for variations in the speed with which the film is fed to the winding-up gear, and for the gradual increasing diameter of the winding reel; sixthly, a reel for holding the web, so constructed that a web wound upon it may be removed laterally without unwinding, and another web placed upon it; seventhly, an arrangement to retard the feeding of the web from the supply reel. By referring to the accompanying two sketches, of which Fig. XXI. is a view looking at one side of the machine and Fig. XXII. a view looking upon the opposite side, it will be easy to understand the action of the machine. The film 33 is in the shape of an endless web, the greater portion of which is carried by the reel 34. When the web has threaded into the position shown, motion is given to the driving belt by rotating the main shaft through the power belt 4. This rotates the worm shaft 7 and the pulley 14, which gives motion to the driving belt 15. The speed can be varied by turning the crank shaft 9 to the right or left, which carries the friction wheel 6 nearer to or further from the centre of the friction disc 5, through the action of the pinion 17 and rack 16. The driving belt, in co-operation with the pulley 26 and 25, imparts this motion to the web 33. The pulleys 41 and 42 act as an intermittent feed tending to jerk the web 33 through the guide 40 of the projecting apparatus