The Optical Magic Lantern Journal (March 1890)

80 Selections. EXPLosive accidents, which occur in the preparation of -oxygen, may be referred to two principal heads—viz., impure materials, and carelessness or inexperience on the part of the manipulator.— Geo. Kemp. ee « I FIND the common carburetted hydrogen, as supplied by the gas companies, good enough for all practical purposes for enlarging by oxy-hydrogen light). Although ‘the light from the pure hydrogen may be a little whiter, I do not think this will compensate for the increased trouble in making it.— Alfred Harman. =m x WHEN I commenced enlarging by artificial light, I was told by different scientific gentlemen that the limelight was of little or no use for the purpose ; but [ felt determined to try for myself, and on account of its cheapness, steadiness, ‘and ease in working, I prefer itto any other light in existence. —L, Aldis. = * * THE optical lantern has become so useful in so many branches of the photographer’s art, as to render it a necessary part of his apparatus.—2t. @. Hunter. * cf ALWAYS give special attention to the foreground of a picture. Never, if you can avoid it, havea long stretch of lawn or level of any kind between you and the object photographed. ‘Change position until some bush or rock falls within your ‘foreground, if possible. If this cannot be done, bring up the gardener's wheelbarrow, with rake and fork, to break the ‘foreground and aid the relief of those objecis more distant. — Ch, Wager Hull. =x * AN experienced exhibitor once told me that when his stock of limes happened to be exhausted, and time pressed, he made a practice of using a bowl of aclay tobacco pipe as a Substitute.—James Martin. * x x PARAFFIN oil is better suited for the lantern than sperm oil. It gives a sharper and more intense light—J. Af. Turnbull, se * THE curved surface of a lime cylinder does not give off the greatest amount of light until it has become “ pitted’ to some extent.—Jf, Noton. xs * s ANYONE who has viewed one and the same photograph in its original size, and then enlarged upon the screen by a limelight apparatus, cannot have failed to perceive the very imarked difference exhibited by such pictures ; the impression upon the mind of the spectator being much grander in the case of the enlargement. —H. Baden Pritchard. xe s No book ever made a painter, or ever will. Neither can art be practically learned by books, but the written ex perience of others may lend important assistance to the student who understands the task of self-tuition. This is particularly true if he is gifted with such poweérs of perception as will enable him to understand, without any further aid, the instructions as they are given.—(Gev. B, Ayres, <* AN advantage of water colour painting on glass is that, should it be necessary to retouch the painting frequently, it is not so liable to become heavy and coarse, as will frequently happen in using oil colours, which is very detrimental to the painting when seen magnified on the disc.—H. Bielfeld. The Optical Magio Lantern Journal and Photographic Enlarger. Notes and Queries. Optic, J. B., Rev. C. P., Armstrong, Jun., P. Adams. —Replied by post. C. Clark.—Your post card was forwarded to the New York firm, H, Stune.—The address of Dr. E. B. Foote, jun., is 120, Lexington-avenue, New York. H. Worth.—We think you have no cause for alarm; you will find particulars in the present number. R. G. Wheelev.—We have had complaints that the microscope was not sent, and have written twice to the firm in question, but have received no reply. Disc.—\We have been promised a sketch for next issue. Cartoonist writes:—“ What class of lantern gives the sharpest definition for projection ona large scale? 2. What appliance do I need to fix very large drawings, &c., on a sensitised surface screen? 3. Can four mirrors be so placed that by standing in the midst of them the image of a Person is seen projected from them, not merely reflected? 4. Howdid Mr. J. Sang, of Kirkaldy, Scotland, impart stereoscopic effects to copies and paintings. It is said that these effects obtained are more wonderful than those produced by an ordinary stereoscope.” Repl.—1. It depends entirely upon the lenses, especially the object glass. 2. Project the image on a sensitised surface and develop it. 3. It cannot be done by four plane mirrors, but it can by a concave one. 4. By photographing the engraving in its ordinary state and then cutting and slightly displacing the various parts and again photographing it. Conrstant Reader inquires where he can obtain the following :--1. Wood boxes, 34in. square, for sending slides by rail and parcel post, and price. 2. Also pictures of Friendless Bob, Buy your own Cherries, Peep Behind Scenes, portraits of celebrities, &c., for copying purpeses. 3. Also if he can get designs for comic slides, &c., and the price; if not, how come all the firms in England to have slides exactly the same ? Do they hire negatives? If so, where can he hire? 4. Comic slipping frames and price. [Will some reader please forward us the information ?—Ep. ] Andrew C. Cole writes :—‘I observe Mr. F. Vaughan asks in the December issue for some particulars to aid him in colouring comic slides. I enclose particulars which may perhaps aid him, and I hope many others.” (See page 78. ) J. W. inquires :—“ Where can I obtain grooved wood suitable for lining a box, in order to fit it for keeping transparencies in.” (Perhaps some reader will kindly inform our correspondent. —Ep.) Silver Print writes :—I enclose two prints, both from the same sheet of paper and printed from the same negative ; but they are not quite the same, as you will observe if you measure the length of the face. I have been an amateur photographer for more than six months, and have not met with this defect before. Can you tell me the cause?” slnswer.—Paper stretches unequally when wet; and one print has been cut out across the sheet. In order to avoid this defect, all the paper must be cut the same way of the sheet. H. Birt asks for a simple means of testing gas before using. teply.—Fill a small india-rubber balloon with the gas to be tested and fit a small metal tube at the mouth ; then apply a light. If hydrogen only be present it will burn with a blue flame; if oxygen, the intensity of the light from the match will be increased ; if the gas is mixed, it will burn until the pressure is released, when it will explode, but being ona small scale, no harm wil] be done. 102 THE colour of lantern slides produced by eikonogen varies according to the strength of. the developer.—Ch. Z. Mitchell, M.D.