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30 THE PHOTOGRAPHIC NEWS. [January 9, 1891. from 4 to 4} pfennigs per hour. The effect of the flame and its whiteness are brilliant. Schirm's New Flash-Lamp.—Upon a very similar prin ciple the benzine flash-lamp of Schirm has been con structed. The apparatus consists of a tin vessel, a, filled with spongy matter, which is soaked with benzine. All free liquid is poured off. A small tube, c, which empties into the vessel, is connected with a pneumatic apparatus. This apparatus (rubber bulb) must be provided with two valves which carry the air only in one direction, and prevent a back-suction from the flame. In the upper part of the lamp is a cover, d, that can be screwed off, with fine openings around a circular line. Above the middle of this circle with the opening for the gas passage, the mag nesium blow-pipe, e, with the magnesium carrier, f can be inserted. This blow-pipe is connected by a thin rubber tube, g, with a pipe-end, h, near the pipe c. Close to the above-described burner is a small tube, i, filled with a wick, at whose end the flame is burning, which serves to ignite the emitted gas. The action of the apparatus is the following: By pres sure upon the bulb air is forced through the vessel and is fed with benzine gases, passes partly through the ring of fine openings <1, ignites at the flame i, and forms a long, extremely intense flame. Another part of the air, satu rated with combustible gas, passes through the magnesium conducting-pipe e, receives here the magnesium powder, and conducts it to the above-mentioned flame for com bustion. In this way an extremely intense and complete combustion is obtained, and the illuminating power of the burning magnesium powder is considerably increased. This new lamp combines the advantage of the Bunsen burner (with great heating power) with the easy transport ing facility of the former spirit lamp, harmless manipula tion, great economy in burning material, and increased illuminating power. While the spirit lamp, when fre quently used, had always to be refilled again, and a con siderable consumption of burning material took place, one filling will now be sufficient for 1,000 flashes, and the lamp, containing no free liquid, can be transported with out inconvenience. Every danger is also excluded, as in case of an upsetting of the lamp no combustible matter will run out, and the small flame will be at once extin guished. The magnesium supply for this lamp is so arranged that as soon as the magnesium reservoir stands upright the magnesium powder will fill the blow-pipe of its own accord, and a slight tap on the lamp is sufficient, after each flash, to effect a new fill with the powder. If the magnesium reservoir is turned over the magnesium supply is shut off. To fill the lamp the screw, k, is opened, a quantity of benzine is poured in, and the opening is closed again. After unscrewing the cover, which protects the ring of fine gas passages, d, during transportation, insertion of the blow-pipe into the middle of this opening, ignition of the flame, and opening of the magnesium reservoir, the apparatus is ready for use. To keep the apparatus in order, the small opening, d, should be cleaned sometimes with a needle, and it should not be neglected to turn the reservoir over before the last flash, to prevent the magnesium powder from reaching the lamp part during transportation. As soon as the flame becomes weak and is not very perceptible, a new filling is required. If a continued light-stream (by blowing, for instance) is driven through the lamp, and the magnesium reservoir is slightly tapped with the fingers, a lasting light can be produced.—Anthony's Photographic Bulletin. PHOTOGRAPHY IN VIENNA. The History of Photography—Orthochromatic Photo graphy—A Correction—Cristallos. The History of Photography. —The only history of photo graphy at present in existence is written in English. But the materials have increased so much, and the subject is so interesting, that several German authors are busy meet ing this want in literature. In the first place, J. M. Eder, in his great “Handbuch,” has devoted much space to the historical department with rare thoroughness, collecting all information about light and its effects from the times of the Greeks and Romans down to Daguerre. But from there he rapidly passes in review the development of photography. A second work, of which a preliminary notice has already appeared, is being prepared by an author named Charles Schiendl. It is likely to form a portly 8vo. volume. This book passes rapidly over the beginning of photo-chemistry, but becomes more detailed from that point on when the first pictures were produced by camera. Doubtless it will be interesting reading, as the author has the advantage of the valuable help of Davanne, Carey Lea, and other leading men. Orthochromatic Photography. — Recently the learned Berlin investigators, Dr. H. W. Vogel and Dr. Neuhauss, have been engaged in an interesting enquiry concerning the priority of the discovery of orthochromatic photo graphy. This controversy is likely to throw a light not only on the chronological succession of the theoretical speculations which preceded the practical success, but also on the real nature of the thing itself. In a technical journal here, Dr. Neuhauss has described the matter very objectively, it would seem, as follows:— “ In practical photography it has long been known as a fact that the addition of silver iodide to silver chloride or silver bromide greatly increases the sensitiveness of the silver salts for those spectral colours which are near the red end of the spectrum. To explain this phenomenon, Schultz-Sellack made several experiments, guided by the thought of the connection between the absorption and the chemical action of the rays. Such a connection had been made probable by Herschel’s experiments concerning the fading of vegetable colouring matters, and by Draper’s experiments on the decomposition of oxalate of iron. “According to the method described by him, Schultz- Sellack melted the silver salts to masses clear as glass, which are particularly adapted for investigating optic absorption, and which change but slowly under the action of light. In this condition silver chloride is colourless ; iodide light yellow and transparent; silver bromide is a