The Optical Magic Lantern Journal (May 1895)

84 The Optical Magic Lantern Journal and Photographic Enlarger. all, the cylinder system was really the best, and who, coming to no conclusion on the subject, have continued to go on as before. And in the minds of such the question has again arisen on hearing of the late fatal accident. ; When the present cylinder system was introduced, it was claimed that the great safety of cylinders lay in the fact that it was impossible for the user to get an explosive mixture, a point which was readily conceded by anyone who gave the subject a moment’s thought; but, unfortunately, recent events go to show that cylinders have brought in their train a new series of dangers which were unknown when bags were solely used. It is often argued that accidents are less numerous with cylinders than they were with bags, notwithstanding the increased use of the former; this is very probably true, but the argument is beside the mark, as it is the results of explosions rather than their rarity which have to be considered. For instance, if the late accident instead of affecting a solitary individual, had taken place in the midst of a bank-holiday crowd at the same spot, and, say, killed four and injured twenty others, who would venture to assert that such disaster had ever been wrought by the explosion of a bag? The accident on the 15th March, occurring as it did in a public place, almost in the very heart of our excitable Metropolis, has attracted so much attention as to make it certain that the matter will be fully thrashed out ; in fact, in one weekly newspaper not usually addicted to lantern matters, the writer found no less than four paragraphs on the subject in one issue. Another objection to cylinders is that such a lot of fittings seem to be required. [lately saw at work a triple lantern supplied from two large cylinders, the apparatus including no less than ten-wheel valves, two gauges, and two regulators, besides the cylinder valves and usual dissolving taps on the lantern. The arrangement was as follows:—Next to the cylinder valve a wheel-valve was connected, above that again another wheel-valve giving access to a branch on which the pressure gauge was screwed ; on top of all a regulator, and two wheel-valves on each of the jets in the lantern. Now I do not say that all these fittings were necessary, personally I think not, but it stands to reason that the owner of this wonderful kit thought them, if not necessary, at least desirable, or he would not have had them there. Now, hed bags been used nothing more would have been required than the taps on bags and jets, and the dissolvers on the lantern. One point in favour of bags I have not yet seen noticed is, that except when actually in use they are emptied, folded up and put away, and are, so to speak, out of action, whereas cylinders are often kept with the full pressure in them for days, weeks, and even months, unless the valve be leaking. It would seem from the experience of the last few years that accidents with cylinders are invariably fatal, whereas accidents with bags and retorts are often trifling, although I believe there are authentic records of a few fatal accidents. Making one’s own gas may be inconvenient, but it is better to endure that than to have gas compressors refusing to fill one’s cylinder after some fatal accident, a decision against which there is no appeal. Accidents occurring in the use of retorts and bags are always due to gross carelessness, even indifference, on the part of the user, and are often brought about by that peculiar habit many amateurs have of always taking three or four friends with them whenever they have anything to do with lantern exhibitions; and these wellmeaning but wrong-doing folk being allowed to lend a hand in, and interfere with the arrangements, work, each according to his own ideas, and generally assist towards catastrophe. As an instance, a gentleman holding an appointment as county analyst once went to a hall to lecture, using bags, and took with him an assistant and one or two pupils. The bags were filled and placed between the boards, when the assistant noticed that one of them was not as full as it might be, promptly removed it, and connected it to a gas bracket, and filled it; having done so, he discovered that it was the oxygen bag, ard fully realised the extent of the mischief. The lecturer, being appealed to, told him to take the bag and empty it in the open air. He took it into a passage and there tested it witha light. Result :—Damage to assistant, none beyond the shock ; damage to glass, nearly £30. Bags we are told occupy more room than cylinders ; that is so, but as they stand immediately behind the lantern, they occupy room which is of no value as seating space. The trouble of getting weights is another difficulty often brought forward, butit is more theoretical than practical, as for home use the weights wanted can be bought second-hand at about 4s. per cwt., and when away from home weights are often to be found at halls, or, if not, can generally be borrowed from some tradesman in the same street. There seems to be an idea abroad that if the weights are removed or displaced from the bags while the light is burning, either one bag or the other, or both, willimmediately explode. Such a thing could not possibly happen, as both gases