The Optical Magic Lantern Journal (February 1900)

caer The Optical Magic Lantern Journal and Photographic Enlarger. 27 Take equal purts of A and B and add 5 minims of c to each ounce of mixed developer. It will be noticed that this oxalate developer is very much weaker than that which was formerly used for negative work, and that the amount of acid is also in excess. The acid and sugar act as retarders of the developing action, that is, slow it, while the bromide acts as a restrainer. If the development should need acceleration make use of a stronger oxalate and iron solution ; that is, the above with only one-fourth the amount of water. Add a little of this strong solution to the developer to expedite the appearance of the image. Of course do not presume that you may overexpose, and modify in the development the density of the image; for correct exposure must be aimed at, and the endeavour made to adjust the developer to the exposure. The stock solution of mixed ferrous oxalate being intended as a means to this end. It is only in this way that brillancy of results may be attained. It may perhaps be necessary to mention here that in mixing the developer for use the iron should always be added to the oxalate solution, never the oxalate to the iron, This latter procedure would cause muddiness in the solution and practically ruin the developer. ©) Io~ —Eo— —© é The following List, relating to current Patent Applications, is compiled expressly for the ‘‘ Optical Magic Lantern Journal” by W. P. Thompson & Co., Patent Agents, of 322, High Holborn, London, W.C., to whom all enquiries for further information should be addressed. f No. Recent Patent APPLICATIONS. 24607. 11th December, 1899. Birt Acres. A portable brilliant light apparatus for theatrical stage and other illuminating purposes. 24726. 12th December, 1899. Ettienne Jules Marey. Means for regulating the speed of the positive film whilst in motion in cinematographs and like apparatus for optical projection. (Date applied for under Patents, etc., Act, 1883, Sec. 103, 24th May, 1899, being date of application in France.) 24896. 14th December, 1899. Alfred Julius Boult. Improvements in or relating to apparatus for taking and exposing photographic pictures. (Paul, Arthur Joseph, Gasse, Frauce.) 196, 38rd January, 1900. Jacob Strérher. Improvemeots in acetylene lamps or lanterns suitable for bicycles. (Complete.) 311. Sth January, 1900. Leonard Ulrich Kamm. Improvements in apparatus for photographing and exhibiting cinematographic pictures. 432. 8th January, 1900. John Alfred Prestwich. Improved means of exhibiting photographs in rapid succession. 611. 10th January, 1900. . Jose Ferreira Guimarais. Intense lighting apparatus for instantaneous photography. Copies of the following specifications may be obtained by remitting 1/for each specification to W. P. Thompson é Co., Patent Agents, 322, High Holborn, London, W.C. SPECIFICATIONS PUBLISHED. 26722 of 1898. Raleigh. Apparatus for taking photographic views in rapid succession, and for presenting the same in like manner 21755 of 1899. Koopman. Consecutive view apparatus. 21754 of 1899. Koopman. Consecutive view apparatus. 21756 of 1899. Koopman. Consecutive view apparatus. 23217 of 1899. Messter. Apparatus for exhibiting or displaying & series of cinematographic or other pictures. o:-— 4 Gorrespondence. 3 CHEAP LANTERN SLIDES. To Mr. J. Hay Taylor, Editor. Srr,—Cheap lantern slides can be produced from ood process blocks, on varnished glass, which I think better than lithographic slides I do not know of any being done commercially, but I think a trade might be done with them. Yours truly, A.B. VOTE OF THANKS TO THE LANTERNIST. Lo Mr. J. Hay Taylor, Editor. Dear Str,—A few lines in reply to the criticism by “An Operator,” in the January issue, on my letter in your previous number, might not be out of place. Let me respectfully point out to your correspondent ‘that he hus missed the point of my letter. I take it that he is a professional lanternist, and therefore looks on the vote of thanks from a different standpoint. His suggestions for lectures I quite agree with, but cannot see that they have anything to do with the subject, as I originally put it, ‘‘ Vote of Thanks to the Lanternist.” “Your correspondent, agrees that such is only an act of common courtesy. Then why call it a nuisance, and put it in the same category as the chairman’s long-winded opening, the bill printer, the hall keeper, etc. ? My reminder was intended to apply only where the lanternist’s services are gratuitous. “An Operator’ says, in the case of a professional, thanks is uncalled for. I would not go so far;:not necessary would be better, but even in his case.if the work is well done, the thanks of an audience is an incentive to good work later on. Now, with regard to the ‘few shillings,” your correspondent is no doubt aware that the majority of lanternists are amateurs, and are “so foolish as to accept less than