The photographic news

• Bandzählung: 35.1891
• Erscheinungsdatum: 1891
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-189100009
• PURL: http://digital.slub-dresden.de/id1780948042-18910000
• OAI: oai:de:slub-dresden:db:id-1780948042-18910000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

Frohn, Deventer; Anselm Schmitz, Cologne ; H. Tollens, Dordrecht; Angerer V. Goschl, Vienna; Roeloffzen & Hubner, Amsterdam. Honourable mention.—Rud. Schuster, Berlin. Section B.—Amateurs. Hiyhest award—diploma and silver-gilt medal.—Lentz, Maastricht. Silver-gilt medal (given by the Committee). — Bucquet, Paris. Silver-gilt medal (given by the Haarlem Am. Photo. Club).—Motto “ Voorwaarts," Baarn. Silver medal (first prize).—Clement Williams, Halifax ; Dr. Khn, Innsbruck; A. Lunden, Antwerp; W. Toussaint, Amsterdam ; F. P. Cembrano, Richmond. Bronte medal. —A. Bakhuis, 01st; Jonkor van Olden- barnwelt, Utrecht ; A. Tagliaferro, Malta; John E. | Austin, Maidstone ; J. J. M. Guy de Coral, Amsterdam ; Martin J. Harding, Shrewsbury ; J. Court Cole, Oxford ; Van Barnweldt Van Mattheua, Velp; L. Keuters, Ant werp ; J. J. Kamp, Amsterdam. Honourable mention.—Baron Marcy de Tiege, St. Trond ; A. Alfarado, Paris ; Haarlem Amateur Photographic Club (collection) ; L. J. Smit, Kinderdijk ; J. C. Wolterbeek, Amsterdam; G. Peek, Amsterdam; A. W. Gottlieb, Shrewsbury ; G. P. Voorwijk, Amsterdam. Section C. (Manufacturers). Highest award—diploma of honour and silver-gilt medal. — Loman and Co., Amsterdam. Silver medal.—Carl Zeiss, Jena ; W. Watson and Sons, London. Bronze medal.—Meinard Van Os, Amsterdam; H. Muckenstein, Paris ; B. J. Edwards and Co., London. Honourable mention.—Anton N. Bouvy, Amsterdam. INCANDESCENT GAS-LIGHTS. The application of electricity to purposes of illumination has for many years been talked and written about, and yet we are only just beginning to see it coming into common use. There are many reasons for this delay in the adop tion of the electric light which it is not necessary to refer to here, but this delay has had one good effect in stimu lating those who are interested in gas illumination to improve upon old methods of burning the gas, by invent ing new contrivances which shall secure more perfect combustion, and therefore better light, at less expenditure of material. Among the improved contrivances so pro duced, a great deal of interest is attached to the burners known as incandescent, for they seem to be curiously similar both in principle and effect to the electric glow lamps which bear the same name. In the latter case, a thread of carbon is made incandescent by the resistance which it offers to the passage of the electric current, and in the former case the same result is brought about by interposing a network of refractory material in the intensely heated flame of a Bunsen gas-burner. The first lamp on this principle was Lewis’s, who employed a mantle or network of fine platinum wire. This was effective so far as it went, but the metal employed gradually rose in price, from the extensive demand made for it by electrical apparatus makers, as well as by photo graphers, until it became obvious that its price must render it prohibitive. The next lamp which appeared was the La Clamond, which employed a mantle of magnesia; but this arrangement, although effective, required a constant supply of air having been exhibited in this country, never came into practical use. Finally was brought forward the Welsbach incandescent lamp, in which the mantle employed is made of zirconium. This lamp was a great improvement on all those which preceded it, but it had certain faults which for a time prevented its wide adoption. These faults have now been remedied, and the lamp, which is in use in many public buildings in London, is a pronounced success. As this form of lamp—which can be fitted at small expense to any existing gas fittings—is likely to be largely adopted by photographers on account of the actinic value of the light given by it, we took advantage of the invitation given us last week to visit the premises of the Incandescent Gas- Light Company, at Palmer Street, Westminster. Here we not only saw the lamps in operation, but were able to follow the manufacture of their various parts and belong ings, from the raw material to the manufactured article. As already indicated, the foundation of the lamp is a Bunsen burner, which already is familiar enough to all who have anything to do with chemical pursuits ; but this Bunsen burner is of special form, so as to secure the greatest heating power and a large flame. It is crowned with a dome made of fine steel wire, with an upright rod from its apex, about three inches long, to which the zirconium mantle is hung by a thread of asbestos. The whole is enclosed in an ordinary lamp chimney, or the flame can be used as a naked one if required. It may be here mentioned that, in its original form, the mantle support of the Welsbach burner was outside the mantle, and that, as it held the heat after the lamp was extinguished, it led to the unequal expansion of the glass chimney, and frequent fractures were the natural result. Loss from this cause is now obviated without any compensating dis advantage by making the support of the mantle run up its centre like the stick of a partially closed umbrella. By the adoption of this simple device, supporting rod, mantle, and glass all cool down equally and regularly, and this is one of the most notable improvements which have been made. The mantle is founded upon a cone of woven cotton made in a stocking machine, and cut off into lengths of the requisite size. This cotton is dipped into the solution charged with zirconium, and is then dried with the plaster like compound coating every thread. The mantle is next subjected to heat, so that the original cotton is entirely burnt away, leaving a network of white zirconium oxide, which, after being toughened by a bath of collodion, is ready for issue to users of incandescent lamps. Photographers can afford to pay something extra for a white light by which their work can be done during dark weather, but in the case before us there is an actual saving, the incandescent burners consuming less gas than those in common use. It must also be mentioned that the quality of the gas in no way affects the result, inasmuch as the light comes not from the gas itself, which, when used in a Bunsen burner, is actually non-luminous, but from the white-heated mantle of zirconium. Where ordinary house gas is not available the burners can be used in conjunction with the Helios gas machine, which is now employed in many country districts. This apparatus consists of a vessel containing benzoline, or some similar hydro-carbon, associated with which is a fan or blower by which atmospheric air is drawn through the volatile fluid, and is turned into an inflammable gas. A gallon of special oil used with this machine costs fourteen- under pressure, and the lamp, after [pence, and produces about 1,000 feet of gas.