The Optical Magic Lantern Journal (October 1893)

159 The Optical Magic Lantern Journal and Photographic Enlarger. Side by Side Lanterns for Saturators, and Things in General. By New ZEALAND LANTERNIST. Iv would seem that there are almost numberless points of difficulty which beset lanternists all. over the world. One would think that in England, where facilities for acquiring reliable information everywhere exist, that there, difficulties would be easily and satisfactorily overcome, This, however, does not appear to be entirely the case, and I may safely say, that in a far-off land like New Zealand, where lanternists are in the great majority of instances thrown upon the resources of their own intelligence, that there little obstacles present far less trouble than in England. Of course our troubles are largely of the same character, but we cannot fly for refuge and instruction to the ever convenient and providential Editor. You can imagine, sir, that if we had always to wait for editorial information, our lantern work would be very largely made up of what constitutes music—periods of rest, and many of them pretty long ones. If our lenses get mixed, or our lamps persistently refuse to burn, except in the wrong way, or the jets get choked, or the gas bags leak, or the saturator won't work—if indeed, the hundred-and-one incidents peculiar to lantern work occur, we simply have to rely upon our own judgment and reflection, and resolutely master them. I have, however, to confess that our knowledge is sometimes gained in rather startling ways. Some time ago, a clerical friend of mine imported a fine bi-unial, with all accessories for the oxy-ether light. He had, of course, little or no knowledge of the working, and during his first entertainment his audience were kept in a constant and lively expectation, by the salvos of miniature artillery which were ever aud anon proceeding from the immediate vicinity of the reverend operator. The climax was reached when, with a tremendous report, his oxygen bag exploded, filling his audience with unpremeditated alarm and the building with blue vapour. This, of course, was a disastrous effect in more ways than one, for, as he had instituted these entertainments to defray the cost of the lantern, the result has been to frighten the spectators away altogether. I think there can be little doubt that the accident was caused by the pressure on the bag being suddenly removed, and I have supplied him with some flame extinctors, which will prevent these catastrophes in future. There is in this connection a matter of some importance, which, I think, will have to be seriously considered by lanternists generally. There are those who doubt whether the use of the saturator will be permanent. The bulk of, the evidence is, however, against that opinion, especially where much travelling has to be done. What, however, I wish to point out is that the usual form of bi-unial lantern when used in conjunction with the oxy-ether (benzoline or gasoline) light, does not appear to be at all satisfactory; that is where “dissolving” is necessary. J am in the habit of using gasoline in my saturator, and found it extremely difficult at first, to correctly estimate the quantity of liquid requisite for charging. This, I think, must always be the case where one is not constantly operating. If the charge is too small, as the time of an exhibition proceeds the light gradually assumes a dangerous nature. If it is too great, the oxygen pressure forces the liquid from the saturator into the dissolving tap, from which, by its weight, it falls into the tubes of the lower lantern, and any attempt to light up simply results in the tubes being blown off the dissolving tap. All this can of course be prevented by experiment before an exhibition ; but where, as in many instances, tanks are used, and which have to be replenished with oxygen during an evening, the increased pressure which the making of the gas produces is almost bound to force the liquid out of the saturator, and the result is as I have stated above. I think the only preventive of this inconvenience is that the tubes supplying the jets should all ascend at the same level on a sort of inclined plane, and this can only be done with side-by-side lanterns. The advantage of this is, I think, obvious, for the tubes being necessarily all of the same length the pressure is always equal, and this would be an immense help to beginners. Further, there is an opinion being formed that for good registration, better light, and the production of ‘ effects,” the ‘Norman tower” style is unsatisfactory, and will be superseded by the side-by-side form. The lowering or raising of the front tubes to obtain coincidence of discs cannot but be detrimental to perfect focussing, and it has the further disadvantage of deflecting the condensers from their proper axis with the light. Iam not aware that any manufacturer has yet constructed a side-by-side bi-unial, but, I. think, such a form, with good facilities for ‘‘effect’’ work, would, both for