The Optical Magic Lantern Journal (August 1893)

110 The Optical Magic Lantern Journal and Photographic Enlarger. Tue First Annual Exhibition of the Midland Camera Club will be held at the Botanical Gardens, Moseley, Birmingham, from October Qnd to 14th. Full particulars may be obtained from the hon. sec., Mr. C. Jevons Fowler, 4, Woodstock-road, Moseley, Birmingham. Lantern condensers made of glass composed of sand 70 parts, china clay 25 parts, and soda 34 parts are, we hear, to be the article of the future, as a German chemist states that it is almost an impossibility to crack them in the ordinary course of a lantern exhibition. * * # One hears at times some queer descriptions of lenses. A short time ago, when a contemporary was describing the lens of a particular hand-camera, the editor stated that the single achromatic lens with which it was fitted was a double achromatic lens; probably he had just found out that it consisted of two glasses cemented together, and so inferred that the proper designation was ‘‘double’’; this is almost on a par with the optician’s assistant who spoke of a crossmatic lens, and when the customer asked what sort that was, replied that “it was one that made the rays of light cross the axis, this make being much better than the common kind,” WE learn that a firm in Japan intend sending sets of native hand-painted slides to this country. The slides are painted on gelatine and are said to be excellent even in the finest detail. :0:—— A Gomplex (Polytechnic) Slide and How to Make It. In our June issue, Mr. Wilkie made mention of an ingenious slide representing Cupid shooting an arrow, which etfect created a great sensation at the Royal Polytechnic many years ago. As we had several inquiries respecting the mode by which it was effected, we bave obtained the identical slide used, and will endeavour to give such an explanation as will enable those possessing an artistic and mechanical turn to make one, which, when projected upon the screen, will present an astonishing and pleasing effect. As this slide is the property of Mr. W. RB. Hill, it must be understood that, although no objection is offered to any of our readers making one for their own use, it must not be made for commercial purposes without the permission of the owner. It was designed by the late Mr. Childe, and drawn and painted by Mr. Hill. We understand that up to the present but two people besides ourselves have had an opportunity of inspecting the mode of working of this slide. In the following cuts, each part has been made in exact proportion, so that little difficulty should be experienced by those who may wish to make one. On the glass, which is afterwards fastened in the frame shown at Fig. 1, is painted the major Fig. 1. part of the figure, which should then be blocked out to the edges with opaque varnish, excepting the small portion D seen at the right hand side, which is left blank for reasons which will presently be explained. On the under side of the glass, Fig. 2, is painted in the position indicated, an arm holding a bow. On the right hand of this will be seen an opaque Fig. 2. | Pci os, patch, the object of which will also be obvious presently. Levers, which can be rade of cardboard, must be attached, and a hole made in the shorter arm at b. Care must be taken when cutting the strip of : Fig. 3. glass, Fig. 3, and at the place shown must Be painted (also on the under side) an arrow. This strip may be made partly of glass and partly of ~ cardboard, the junction being made at the line indicated, and a hole bored at C.