The Optical Magic Lantern Journal (August 1898)

The Optical Magic Lantern Journal and Photographic Enlarger. 119 the view, touch the underside of it with the tip of the tongue, press it down on the film and it will adhere firmly. Place a well-cleaned cover glass over this. Next take one of the binding strips; wet as much of it, with the tongue or otherwise, as will be required for one end of the slide, lay it face up on the table, take the slide with its mat and cover, holding them firmly together, and place the edge longitudinally in the centre of the strip flush to the end; lay the sides of the strip up against the sides of the slide. We have then one end of the slide bound with the strip. Then wet enough of the strip for the adjoining side and bind that ; and so on for the other end and side. Cut the corners off, the parts that stick out, and fold one over the other. In this way a neat binding will be obtained. Put a thumb piece on the lower left corner to serve as a guide when putting them through the lantern. in what is known as the lanternscope before binding them, to save the trouble of doing this work on those which do not come up to the standard. Notes on Sundry Lantern Matters. By T. PERKINS. “2 N a box of lantern slides which came | D 1 | reason, a mask is used it must be put on the under my notice a short time ago, were ruined by the fact that the vertical and horizontal lines, though all the vertical lines were parallel to one another and perpendicular to the horizontal, were not parallel to the sides of the lantern plate. Probably the slides were made from hand camera shots, and the camera had been tilted to one side, though | the plane of the negative plate had been kept vertical. It would have been easy to correct this in printing had a frame larger than a quarter-plate one been used, but probably the photographer who made the slide had only quarter-plate frames by him. I have sometimes had the ill-luck to get slides with a similar error on them from a different cause, namely, | ; development, showed the cracks as two parallel the slipping of the transparency plate in my reducing camera, and it generally happens that the slides showing this defect are so good in other respects that one does not care to throw them into the hydrochloric acid bath to remove the film and convert them into cover-glasses. In such cases there is an easy plan which I generally adopt, I simply trim the transparency d It is best, however, to : run the slides through the lantern or test them | several otherwise admirable slides | asI would trim a print, using a glass cutter instead of a knife, taking care to get the edges of the plate parallel to the lines that should be vertical and horizontal respectively. The cheap glass cutting wheels answer admirably for cutting glass, they are inexpensive, and if by use they get blunt, they can be easily sharpened by knocking out the pin on which the wheel revolves, sticking a bit of wire through the hole | in the centre of the wheel and fixing it on a lathe and holding a hone against its sides while the lathe is worked. When the lantern slide is trimmed it is of course reduced in size, and will be rather awkward to mount on the cover-glass, but if a card is cut 84 inches square, with a central aperture into which the trimmed glass will fit accurately, it can be fastened in its place with a small piece or two of a binding strip and then laid on the cover-glass and bound up neatly and securely. If the defective negative is a quarter-plate one, and we use a 56 by 4 or halfplate printing frame in which a piece of plain glass has been inserted, we can so adjust the lantern plate that we can print the transparency correctly at once. In this case, however, part of the lantern plate will be exposed beyond the edges of the negative and it will be necessary to use a mask, otherwise the light entering at the edge might encroach on the lantern plate and cause fog. Whenever, for this or any other back of the negative and not between it and the transparency plate, or sharpness will be lost, for the plate, unlike printing paper, cannot be pressed into close contact if there is a mask, even of thin paper, between it and the negative. I recently lent a half-plate negative to a friend to make a slide from it ; it was a poor flat thing, but valuable because I could not get another of the same subject; in transit it got cracked. My friend, before returning it, fastened it securely by binding strips to a sheet of glass of the same size, and by careful printing, a paper print in which the crack was hardly perceptible could be obtained ; but lest the crack should get worse I resolved to make at once a transparency by contact; this I did, using an ordinary negative plate. This, on lines quite close together, one transparent, one opaque. The transparency was developed so as to increase the contrasts, but was somewhat thin; I intensified it and then carefully retouched it so as to get rid of the transparent line due to the crack, then I made from ita negative by contact, which, by giving a some