The Optical Magic Lantern Journal (July 1892)

76 The Optical Magio Lantern Journal and Photographio Enlarger. will rapidly take the place of those which are! rivetted. x * 2 A Goop varnish for collodion lantern slides consists of a solution of gelatine in strong acetic acid, and which is then thinned with water until it becomes of the consistency of syrup; this is poured on the plate in the ordinary manner. *x * * Mr. FRANK Howarp gives the following precautions for avoiding the smell so often noticeable with oil lanterns. When the lamp is done with, the oil that can be got to run out should be poured off; then the wicks must be re-lighted and allowed to burn right out. It must not be charged with oil again until it is in position and about to be used. No smell of any disagreeable character will thus be noticed. al * * ALUMINIUM is recommended to take the place of magnesium for lighting, as it burns slower and without smoke. The powder is projected into | the flame of an oxygen jet, and the composition, which is found to work with good results, is:— Powdered aluminium... 100 parts. Lycopodium 2 4 Nitrate of ammonium se ar * : | THE following readers of papers (Session 1891-2) | have been awarded the Society of <Art’s silver | medal : Prof. Thompson, F.R.S., ‘' Measurement of Lenses ’’; G. H. Robertson, F.C.S., ‘‘Secondary Batteries’’; Captain Younghusband, ‘ The Pamirs"’; Prof. V. B. Lewes, “Spontaneous Tgnition of Coal’’; R.S. McCormack, ‘“ Trade Relations of Britain and U.S.” ; Captain W. de W. Abney, C.B., F.R.S., “Colour Blindness” ; F, E, Ives, ‘Composite Heliochromy.” * * * THE Photographic Convention will meet at Edinburgh on rith inst. The proceedings will commence at 6.30 in the hall of the Geographical Society, during which a lantern exhibition will | take place. The 12th inst. will be devoted to | outings; 13th is what is called “the technical | day’’; 14th, excursion and lectures; 15th, pleasure, including a dinner and smoking concert: 16th, meeting ‘of officers only. | * 1 Tue Eastman biases of New York has lately been consolidated with the New Process Film Co., under the name of the Eastman Kodak Co., N. Y. Ir is announced that iron rust, contrary to the common statement, is not always a hydrated sesqui-oxide of iron, Prof. Liversedge has collected a number of specimens of rust, and in almost every case has found more or less magnetic | oxide which has been attracted by a magnet. Hand-Cameras for Obtaining Slides for the Lantern. ' Facile" . (Fallowfield) ... . see March lst, 1890. No.1 ‘‘Giah” ... .... (Mawson & Swan) .. ... 4, May Ist, ,, » 2 Quadrant’... (W. HL Humphries & Co.) »» June Ist, ,, » 3 ‘* Eclipse” » GJ. l. Shew & Co.)... «5, July Ast, ,, » 4 ‘ Eureka” . (W. W. Rouch & Co.) 5, Aug. Ist, ,, ny (8 Key” .. (Platinotype Co.) . » Sept. Ist, ,, », 6 “Optimus” .... (Perken, Son & Rayment) », Oct. Ist, ,, » 7 “The Griffin (Griffin & Sons, Euattse) » Nov. lst, ,, » 8 ‘The SwindenEarp” Patent és » Dec. lst, ,, » 9 “Collins” .... (C. G. Collins) » Feb. Ist, 1891. » 10“ Kodak” . (Eastman Co.) ... » Mar. Ist, ,, » 11 Guinea” . (WalterGriffith) ... si April Ist, 4 », 12 ‘*Vanneck” .... (Watson & Sons)... » May Ist, ,, » 13 “Chadwicks” = (W. I, Chadwick) »» June lst, ,, » 14 “Bonanza” ... (R. & A. J. Mercer) », July Ist, ,, yy 15 “Repeater” ws. (J. FP. Shew & Co) » Aug. Ist, ,, » 16 ‘‘ Marvel” + (Wilson & Son) « sear gg -DEPe USt,, 5 » 17 ‘*Talmer” (Talbot & Eamer) sav 4gr> Cts. ASty wi » 18 “The Omnigraph ° (J. Lancaster & Son)... » Nov. Ist, . », 19 ** Ubique ts (Perken, Son & Rayment) » May Ist, 1892. », 20 “* Daylight Kodak” (Eastman Company) » June lst, ,, No. 21.—“ THE RADIAL.” One of the many advantages of the Radial Hand| Camera introduced by Messrs. Marion, of Soho; square, is that it is possible to carry a supply of plates of varying rapidity, and to expose any particular plate according to the nature of the subject. It will thus be seen that it is not necessary that the plates be exposed merely in rotation according to their order in the magazine portion of the camera. The plates are inserted without any backing or sheaths in a series of grooves, which are exposed to view by removing the back of the instrument; these grooves radiate from a common centre, this centre being the pivot on which the exposing plane turns (see E, Fig 1). QO TLL ZUMA u aT Sen MGTIO RIC ii The grooves spoken of are made of metal, : there is no chance of a plate sticking, or ithe ' accuracy of the fittings getting out of order,