The Optical Magic Lantern Journal (July 1896)

The Optical Magic Lantern Journal and Photographic Enlarger. 111 ‘« Bray’s 0000.” Were this small sized burner used with house-gas, the result would only compare with a poor quality of candle, but this small burner with acetylene gas will give a clear, bright and small light. By placing two or more of these burners, say half an inch apart, a stronger light is obtained. Those who are in possession of one of the Fig. I. well-known holders for the incandescent light as applied to the lantern Tig. I., can with little difficulty adapt it for use with acetylene. Having unscrewed the incandescent burner, make a T piece similar to Fig. IJ., provided as shown with three burners of the size mentioned, half an inch apart, and screw this on the support at (4), when the necessary qualifications for burning acetylene gas in the lantern will be fulfilled. 20: Photography for Proselyting. Wuen on a recent visit to the Channel Islands we observed two photographs exhibited in a shop at St. Peter’s, Guernsey, evidently in the interests of the Salvation Army. An “army ’”’ man and woman were standing behind two chairs, on which were seated two rough looking men, in dilapidated dress, boots, etc., and on whose faces were depicted the wellknown expression due to a too frequent acquaintance with the bottle. The ‘ Armyites”’ were standing with their hands laid on the shoulders of the two front sitters, the faces of the former being carefully retouched, and those of the latter severely left alone. This picture betokened—-see what we are about to take in hand. Alongside of this picture was another, the relative positions of the four figures being the same, but in this instance the two men sitting on the chairs were dressed (like the others) in the army uniform, and they possessed a great degree of smartness even to the waxing of the moustache; their faces in this instance. were retouched. This picture said in effect— see two reformed reprobates. As a means of advertising the army, the general effect was, to the casual observer, as least catching; but on carefully looking into the picture it was obseryable that the two sittings were made within a few minutes of each other, instead of, as one would be led to believe, at least a few months apart, for the figures in the back were in the same positions, and even had the same folds in their clothes, the same amouut of necktie showing, in fact the same everything ; the accessories were also in exactly the same relative positions with respect to the figured linoleum on the floor. In this case who should be to blame— the sitters for being taken under circumstances that portend to be at some considerable time one from the other, or the photographer for not displacing the accessories, and at least getting the sitters behind to undo their coats, and button them anew ? :0:—— Oxygen, Its Manufacture, Storage, and Use.—V. By Epwunp H. WitsIE (Of the Late Royal Polytechnic Institution). Au the processes of manufacturing oxygen gas which have been touched upon so far, resembled each other in this respect: that very little heat was necessary, a Small gas burner or spirit lamp being sufficient, but there are other processes in which a very much greater amount of heat is required to cause the gas to generate. Oxide of manganese heated in a suitable retort to a bright red gives off a considerable quantity of oxygen, and as all the gas used for chemical experiments and lime-light lanterns in the late Royal Polytechnic Institution was mace in this manner, it will perhaps be interesting to many of the readers of this Journal if we pay an imaginary visit to the gas-house of that Insti | tution and inspect the apparatus as it appeared twenty five years ago. The whole plant was extremely simple, but as near perfect as possible in working, and to assist my description I have drawn from memory the interior of the gas-house, showing the positions of the furnace, purifier, and gasometers. The gas-house was situated under the large theatre and close to the optical room, so that the gasometers were not any considerable distance from the lanterns, and both oxygen and hydrogen (house-gas) were laid on by lengths of ordinary one-inch iron gas barrel all over the