Volltext Seite (XML)
32 THE PHOTOGRAPHIC NEWS. [JANTARY 12, 1883. means of intensifying the invisible rays, stating that they might set London on fire by these rays, that produced no light, but enormous heat when intensified. Accidentally, indeed, when experimentalising, he once got into a position where these rays impinged on his coat, and his attention was called to the fact that his coat was actually smoking. In illustration of this he showed how various articles ignited at an invisible focus. The human eye, indeed, was a photographic plate prepared for the reception of certain rays, and unaffected by other rays. These invisible rays, however, were rendered visible by specially- prepared paper at the end of the screen. There were substances which had the power of drinking-in light and giving it out again, and these were phosphorescent subjects. From these luminous paint was produced, and he showed that the face of a clock covered with this substance shone in darkness. It would be a great boon if light of this kind could be used in coal mines, but thus far it had not been’found of sufficient intensity to illuminate the workings of the miners, because a coal-mine'was a very dark place. In conclusion, Professor Tyndall illustrated by experi- ments the subject of spectrum-analysis.—Daily Chronicle. A Misprint.—Mr. G. W. Austen, who is so well known as an enlarger and transfer painter to the profession, calls our attention to the circumstance that his address is given in the advertising columns of the Year-Book as 61, Riversdale Road, Highbury Vale ; but the correct number is 31. Mr. Farmer’s Lectures.—An additional short lecture on Elementary Photographic Chemistry will be given at the Poly technic on Saturday next and succeeding weeks at 815 p.m., for the benefit of students attending the course. Messrs. Elliott and Fry.—On Friday evening last the employees at the silver and carbon printing works at Barnet held a soiree at Talbot House, Barnet, kindly placed at their disposal for the occasion by the firm. The various rooms were artistically decorated with evergreens, &c., and appropriate mottos. A varied entertainment, including vocal and instru mental music, was provided. At the supper which followed the chair was taken by the respected manager, Mr. II. Ottoway, the duties of vice-chairman being fulfilled by Mr. Skelton. The toasts of " Prosperity to the Firm,’’ “The Manager,” " Visitors,” &c., were proposed and responded to ; and on the removal of the cloth, the room was cleared for dancing, which was kept up in spirit until the approach of the " small hours,” when the company dispersed, after singing the National Anthem. Manufacturing Emulsions.—A new process of manufacturing photographic emulsions has been patented by Thomas H. McCalten, of Philadelphia, Pa. On an upright shaft fitted for revolution at a high speed, is a cross-arm, from which are sus pended vessels by jointed links. Within these vessels are fitted glass vessels provided with funnels near their lower ends. The emulsion is placed in the vessel and the shaft rotated, the centri fugal force and gravity causing the excess of silver salts to pass through and beneath the funnels to be used again.— Picture and Art Trade. Uo Gurxesgondents. *,* We cannot undertake to return rejected communications, *,* Contributors’ Copies of Year-Book.—There are several contributors to our Year-Book who have not yet received copies, owing to the circumstance that we have not their addresses. The publishers will be glad to hear of any omission of this nature, in order that it maybe rectified as soon as possible. William V. Morris.—1. In order to adapt the apparatus for portraiture at close quarters, it would be well to so arrange it that the camera will expand to about sixteen inches. 2. Make a conical extending piece, which can be attached to the front. Samvel.—Take a walk along Thames Street, and you will see them exposed to view at several warehouses. H. Willett.—1. It does not make any difference as regards the drying, more especially as everything soluble is washed out. 2. Use the pure salt, by all means. RESTAL Riggs.—1. A new edition has just been issued, and can = be had from Messrs. Churchill, of New Burlington Street. 2. Unfortunately, we do not know his address. V. G. (Soho Square).—The best process is that of Capt. Abney, and details will be found on page 77 of the last volume of the Photographic News. A Constant Reader.—We believe it is a practically useful arrangement. S. P. G.—No chemical will serve, and you will only obtain sensi tiveness by carefully studying and fulfilling a great number of conditions. Subscriber.—There is reason io believe that they are consider ably more permanent than ordinary prints on albumenised paper. R. P.—They will be republished in the course of a few weeks. A Poor Optician.—Considering everything, you had better obtain the “ rapid,” as it is often absolutely necessary to obtain pictures when the light is very poor indeed. J. Davidson.—Obtain Mr. Burton’s “AB C,” which is pub lished at our Offiee. E. Gilbert.—1. There is no method, as far as we know, of obtaining the tone you desire, for if the prints are toned in the ordinary way before immersion in the bichloride solution, the ordinary result is not obtained. 2. It is a common complaint, but the difliculty is obviated to some extent by fuming. ' Some valuable bints may be gathered from a paper which Mr. Valentine Blanchard contributes to the Year-Book. E. A. T. Ladder.—Under the circumstances, you had better use sulphide of potassium. Make a strong solution, and add as much as is required to each batch of liquor. W. T. Maitland.—1. The change is of very doubtful advisability, but it is impossible to judge properly unless detailed information is sent. 2. They were published in the year 1864; but it will not be by any means easy to obtain them at the present time. 3. A portrait lens stopped down will answer quite well, provided that i you do not attempt to stain the lens by using an over large plate, i 4. When kept for some years it invariably becomes hard and useless. H. Tomlins.—1. Because you have excluded the air. 2. Merely as a means of making the film adhere. C. Benwell.—Not at present. *,* Several answers are unavoidably postponed. Nature says :—“ All interested in photography will find much that is useful and curious in Mr. Baden Pritchard’s Year-Book of Photography for 1883.” The Year-Book of Photography, Edited by H. Baden Pritchard, F.C.S. “ Amateur as well as professional artists will find abundant interest in this capital annual, which ‘ is crowded with useful information.’”—Daily Chronicle. NOW READY, price 1/-, per post 1/3, THE Aear - 8ook of Hgotography AND PHOTOGRAPHIC NEWS ALMANAC, FOR 1883. Edited by H. BADEN PRITCHARD, F.C.S,, Late Hon. Secretary of the Photographic Society of Great Britain. WITH PORTRAITS OF SIR CHARLES WHEATSTONE AND MR. W. B. WOODBURY. STANDARD FORMULAE, corrected and enlarged. JOTTINGS, useful and interesting. EVERYDAY EXPERIENCES. The PHOTOGRAPHIC LENS, its Birth and History. The COLLOTYPE PROCESS IN PRACTICE. DARK ROOMS and their Construction. GELATINE EMULSION for Professional and Amateur Photographers. Practical Details of Daguerreotype, Collodion, Platino- type, Iron Printing, Silver Printing, Carbon Printing, Photo-Lithography, &c. A List of all PHOTOGRAPHIC SOCIETIES and JOURNALS in the world, corrected to date. Original Articles by the most eminent Photographers of the day. Photographic Poisons and their Antidotes. Illustrated with. Numerous Wood-cuts. PIPER & CARTER, 5, Castle Street, Holborn, E.C.
