The Optical Magic Lantern Journal (December 1901)

The Optical Magic Lantern Journal and Photographic Enlarger. 99 latter consisted of a tube tightly packed | throughout its length by exceedingly fine wire, which acted as a preventative to firing back. G represents a thin circular slab of wood (with strengthening piece at right angles). This was attached to the four rods connected with H, upon which weights were placed. This, sliding downwards on the guide 1, served to press the contents of the bladder or rubber bag towards the jet, vid K, on to the lime cylinder 1, which was slowly rotated by clockwork (not shown in sketch). The frame mm, which supports the body of the lantern, was capable of sliding backwards or forwards in a beading, 30 as to adjust the correct distance between the illuminant and the condenser, while the lateral movement was provided at the screws ny, which also permitted of the lantern being slightly tilted. The jet itself had a screw adjustment whereby it could be set at the proper height. The reservoir », of which several were kept at hand, contained the gases ready mixed and was screwed on between the two taps shown, so that one tap closed the reservoir and the other the end of the tubing to which it was attached. On squeezing the reservoir © with: the taps open, F became filled, and after closing the two taps alluded to and opening that connecting with the jet, the weights on n caused the pressure board a to exert its influence in feeding the contents of F to the jet. From time to time r was filled up in like manner from x, and when this latter was empty a new one was attached. The condenser was screwed into the brass plate o. To the present-day worker with compressed gas and automatic regulators, the above apparatus shows what care and attention were required in working an outfit of this description. given with it, and we have failed to learn that any mishap occurred through its use. Vagaries & Variations of Popular Taste in Lantern Exnibitions.— No. I. By W.-H. GOLDING. HESE lanterns, mentioned in last issue of this Journal, were first used by side, but afterwards Al combined or superposed, forming : the bi-unial lantern, usually having a polished mahogany body lined with oe sheet metal, with a space between the ay body and its lining for ventilation and the escape of heated air; a very considerable improvement, both in elegance of appearance and convenience of manipulation, upon the cruder and less sightly instruments previously described. And it cannot be questioned that audiences generally like to see handsome and imposing looking apparatus, and are apt to appreciate the effects produced by their aid more highly than equally successful results if attained by less sightly and attractive means. | The bi-unial lantern naturally suggested further developments in the direction of the use of a third or even a fourth lantern, which lent themselves to the production of the elaborate effects already referred to, which require two or more pictures to be superposed in order to obtain the representation desired. By their aid windows can be Ap a i, NM \ side gradually illuminated, lamps lighted and extinguished, a volcano caused to burst into eruption and again to subside into repose, and many other realistic movements brought before the spectators. The accuracy of registration required for such a purpose, so that every part of a composite picture shall fit precisely into its proper position, is difficult, if not impossible to attain without the aid of photography, whereby any number of duplicate copies of a scene can be produced, to be afterwards combined as required. Some of the effects, such as the firing of a shell in ‘ Torpedo ° Warfare,” shown at the late Royal Polytechnic Institution, required four or more lanterns to be in use at once, an arrangement well within the resources of that institution, at which, as well as in his public lectures and entertainments throughout the country, the triple lantern with the slides to be used in it was carried to the | highest perfection by Prof. B. J. Malden, who Yet numerous scientific demonstrations were | was ably followed by Mr. Bridgman Smith and other well-known lecturers ; and more recently by Mr. G. H. Snazelle, who has adopted this