The Optical Magic Lantern Journal (August 1890)

“for portrait groups or near objects The Optical Magio Lantern Journal and Photographic Enlarger. 19 scopic view of a brown insect, which he wishes to show life colour. In this case place the plate in a half-saturated solution of bichromate of potash, to which a few drops of hydrochloric acid have been added. The image will rapidly bleach, till it is a pure white, when it must be washed. A weak solution of Schlippe’s salt is poured over it, by which it immediately takes a red colour. But here again precaution must be taken to haveall the solutions weak, else may the image become so dense as to stop the light in too great a degree. In all these processes of toning, it is necessary that the transparency be not allowed to get dry after removing from the water following the fixing and its immersion in the toning solution. Hand Cameras for Obtaining Slides for the Lantern. No. 4.— EUREKA.” StncE the Eureka was first introduced by W. W. Rouch and Co., 180, Strand, in 1887, it has undergone several minor adaptations until it is now a very perfect instrument. This camera is made in three sizes, of which the lantern plate size measures gin. by qin. by gin. In the ordinary form (Fig.1) the receptacle for containing the plates is part of the camera proper. The plates, which are placed in sheaths, are contained in a reservoir, and P are arranged close together, ; Fic. 1. that in the front being kept in focal register by springs. When it is desired to change a plate, a lever, situated at the back, lifts the rear plate into a flexible chamber or bag. It is then grasped by the finger and thumb, by which it is conveyed to the front ready for exposure. Each plate is in this manner moved in turn to the front, until the dozen which the chamber contains have all been exposed. To suit the convenience of those who wish to expose a greater number of plates on an outing, the changing reccptacle is also made detachable, so that all one has todo to attach another charged one is to slide in an ebonite shutter in the front of the box, press a spring knob, when the plate receptacle will become detached, and a new one may be substituted. The changing bag, when not in use, folds into a small compass, and is covered by a lid (Fig. 2),on the inside of which is an ivory slab, upon which can be written in pencil such particulars respecting each plate as may be desired. This camera is so adjusted that all objects beyond 2oft. are in focus, but the focus can be readily adjusted by a scale provided for the purpose. When it is desirous to use this instrument for time exposures, it may be secured to a stand. The entire front can, by a touch on a spring, be removed, thus affording opportunity for employing a stop in the lens (Fig. 3), and for using the cap. The lenses of these cameras are of the rectilinear type, and are of highclass. The shutter, which is of the roller-blind class, is actuated by a small knob in front of the camera. A finder is also provided, and the whole packs into a neat leather satchel. —_—0: Comparison of IIluminants. THERE seems to be a diversity of opinion respecting the relative qualities and intensities of the oxy-ether light in comparison with that produced by oxyhydrogen. In comparing the light given by these two methods, it is not sufficient to use a7y jets at random. It is not a difficult matter to make two burners, which can be made to show either one or the other method superior. The true means of arriving at a comparison of the two lights is to procure burners, each capable of showing these respective methods to the very best advantage. At present there seems to be a slight ‘“ hanging back” about the employment of saturators, but by degrees, as lanternists come to appreciate this method of lantern illumination, there is no doubt that their use will become more general. But in order to make a comparison between two different methods of lighting, each burner must be of that form which is calculated to give the illumination under its best conditions, suited to the conditions of the light. C.J. 30% “Made Up” Statuary Slides. I HAVE lately been experimenting upon methods whereby a statuette may, by a little manceuvring, be presented upon the lantern screen as though the photograph had been taken of a statue of large proportions. In photographing an ordinary small figure, I observed that all the small marks, grain, or inequalities of the surface were reproduced on such a large scale that ithad anything but the appearance that it was intended to represent, but by preparing it in the manner to be described, I have made some very good statuary pictures, to all appearances “true to Nature” (if I may use such a phrase). Of course there must be such surroundings as will give an idea of size ; but first, the surface of the figure must be prepared. This I do by cleaning the plaster statuette as much as possible, taking special care that all dirt is removed from the crevices, then, after gradually warming the figure, I immerse it for a short time into a vessel containing white wax, after which it is carefully withdrawn. When cold it is ready for the operation of mounting. A pretty effect can be made by mounting the statuette upon a rough block to represent a huge stone,