The Optical Magic Lantern Journal (April 1893)

The Optical Magic Lantern Journal and Photographic Enlarger. 71 is best, in consequence of its standing heat. Tn conclusion I would only add, that the foregoing instructions are not for coustructing an elaborate instrument, but a plain, durable and useful article, and which the writer feels sure will find a welcome corner on one of the many shelves to be found in any lanternist’s den. greatest —0:-— Editorial Table. Bscze Boox.—A new volume, termed the Jilue Book for Amatuurs, has just been published by Mr. Walter Sprange, 1, Church Court, Clements Lane, E.C., at 5s. It is I’cap 8vo. in size, and contains about 450 pages of names and addresses of members of photographic societies, besides a couple of interesting illustrations. CaraLoccrs.—Mr. F. W. Weeks, 21, Thorpe Rd., Forest Gate, E, has issued a new list, copy of which we have received. Anyone interested in slide makiny, and would like to have special original slides or sets of their own, will do well to send for this new addition of circular, in which will be found many novelties in t -e way of slides. Mr. G. F. S. Rothwell, who has opened new premises as a photo dealer, at 8, St. Mary’s Street, Manchester, has issued a small catalogue. in which is listed goods of high class. We learn that Mr. Rothwell intends to put upon the market shortly an entirely new form of hand camera. —"'0:——_ Correspondence. RE “LANTERNIST’S ” COMPLAINT. (To the Editor.) Dean Srr.—In reference to the ‘“grumble”’ of the “Liverpool Lanternist’ in your last issue, I do not think he has much to complain of if he can hire slides, cvlinder, regulator, c., for the prices he names. Taking slides, in the first instance, what sort of a slide can you hire in London for less thsn 1s. to 1s. 6d. dozen? or if cheaper, is it worth wasting the gas on them? And then the cylinders, Is. is always paid for this, and anyone in London who would charge for less than 6ft. of gas at a time would indeed bea novelty.—-Yours truly, “ LIMELIGHT.” OXYGEN FROM CYLINDER, AND GAS FROM THE MAIN WITH MIXED JETS, "To the Editor. Dear Sm,—A correspondent in last issue propounded what he called a ‘theory’? on the above subject, and invited criticism thereon. No one could have read his remarks without feeling convinced that the writer knew little or nothing about limelight apparatus. He commenced his argument by stating that roughly speaking a 40 ft. cylinder has a normal capacity of 2 ft. What nonsense! Is his lantern condenser roughly speaking 2 ft. in diameter? Are his limes roughly speaking 15 inches in circumferance® Are his discs ronghly speaking from 30 to 120 ft. in diameter? Is he himself roughly speaking 35 ft. high? And yet these comparisons have the same proportionate error only. It would be simply waste of time to reply to the remainder of this truly wonderful theory (2) and neither would it be ofany practical interest to the ordinary lanternist who understands his apparatus. If the matter was really worth entering into further, no one would be more ready to oblige than— Yours faithfully, Brighton. HORACE HILTON, Limelight Expert. STOPPING UP GAS BURNERS, &., (Lo the Editor.) Dear Sin.—The dodge mentioned in your notes last issue re blocking gas brackets is much inferior we think to the little teat enclosed. These we have used since the general introduction of cylinders, both for stopping gas jets, and also for putting on regulators. In the latter case it serves the double purpose of keeping dirt from getting into regulator, and also should the cylinder valve be leaking, the regulator with this on will fill with gas, and thus automatically stop any escape. Many good wishes for success of your excellent journal.—Yours truly, W. BANKS & CO., Bolton. ‘Lhe article enclosed was an india rubber teat, similar to those used for a baby’s nursing bottle.—Ep.1 GASES AND GAS-BAGS. (To the Editor., Sin,— Replying to ‘‘ Expert,” when asserting that gasbags would soon be things of the past, I was simply stating a fact; even good ones are now practically a drug in the market and can be purchased secondhand for a mere song. I cannot quite see how “ Expert’? can make oxygen gas insmall quantities at 21d. per foot. Chlorate of potash is, or was a short time ago, 103d. per Ib., and «Expert would be fortunate if he could make 2)bs. fill a Yft. gas-bag, not to mention the cost of manganese, wear of retort, firing. and time, and in my opinion, a | sum not less than sixpence must always be allowed for the use of weights when exhibiting away from home, which adds 3d. per foot to the cost of the gas. Now as regards the good and cheap compressed gas I have no intent in advocating any particular maker's oxygen to the detriment of the others; were I to do so I should certainly take some precaution to ascertain that my pet maker's really was the best. The names of the makers whose gas Mr. Haddon analysed has, for obvious reasons, not been stated, but were they to be made public, it would no doubtbe a surprise to many. There are three different qualities of gas now being made in London, and are, or should be, sold-at different prices. These we will call X. Y. Z. X is made from chlorate, and cost 4d. per foot. Y is extracted from the air, and cost 3d. per foot. Z is also extracted trom the air, and costs 2d. per foot. As a practical lantern operator I judge the quality of gas only by its effect when in use. X gives the brighter and best light and should be used when working at a long distance from the screen, or for a large picture, or with the lantern microscope. Y gives sufficient light for all ordinary purposes, such as showing coloured photographs or lecture sets. Z is good enough for use in private houses, schoolrooms, or for experimental work, such us registering slides, &c., for it must be remembered that all lan