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November 23, 1883.] THE PHOTOGRAPHIC NEWS. 747 Filed Oct. 20, 1881. Specimens. Patented in Germany June 5, 1881, No. 17,410; in England, Aug. 12, 1881, No. 8,504 ; in Austria-Hungary, Oct 6, 1881, No. 33,363 ; in France, Oct. 22, 1881, No. 145,472; and in Belgium, Oct. 29, 1881, No. 56,100. Claim. —1. The process of producing colour-printing plates by the aid of a colour-scale, consisting in first producing a number of neutral prints from a given photo-negative, next marking upon one of the neutral prints, on all necessary places, the number or symbol of the colour or combinations of colour on the scale corre sponding with the original colour, next representing upon the remaining neutral prints the desired per centage of colour in its equivalent shade in grey or black, and finally using said prints to produce relief printing plates, substantially as specified. 2. As a new article of manufacture, the colour-scale herein described, provided on its surface with separate series of a number of colours in different tints, and a separate series of different shades of a neutral tint, to correspond with the tints of the colours, the depth of the shade and tint being designated by figures or other symbols, and the whole adapted to be used to indicate the shade of neutral tint corresponding with the desired tint of colour upon the print or object desired, substantially as specified. A CHEAP AND EFFICIENT EXPOSER. BY T. G. WIIATTE. I think the accompanying sketch will almost explain itself. A is a thin india-rubber bag similar to the toy balloons, moistened inside with a drop or two of glycerine, and a little Indian red powder (oxide of iron) put in ; this makes it perfectly opaque. A small hole is drilled in lens mount at B, and a brass tube inserted, to which is secured at one end the opaque bag, and at the other an india- rubber tube with pear-shaped ball, C and D. The ball Dis then clipped withan American clip, to which is glued a couple of pieces of wood to press out air from ball. This closing lens, upon pressing the clip and releasing ball, D, the bag, A, is contracted, and the exposure made. There is no possibility of concussion as in many shutters, and the whole affair can be made for two shillings. After a little practice, exposures may be made as rapidly as with most so-called instantaneous shutters. EOSINE AND OTHER STAINED PLATES. BY FRED E. IVES. It may interest you to to know of my experience with eosine as a sensitizer of silver bromide for yellow light. I have used it only with collodio-bromide plates, but with great success. 1 believe that the action of the cosine is purely chemical, and that nothing depends upon the colouration of the film. I found that the application of a very dilute solution was best, but that even then, the sensitiveness (to yellow light) was enormously increased by carefully washing out as much as possible after it had had time to act on the silver bromide. I applied the eosine solution (simple solution in water) after the plate was coated and washed, then washed again to get nd of colour. A curious fact is that these plates showed no sensitiveness to yellow light when developed with the alkaline pyro, developer, unless there was present a little free silver nitrate. W ith oxalate development the presence of silver nitrate was unnecessary and undesirable. I used the plates immediately after their preparation, without drying. A much better colour sensitizer (when it can be obtained) is a fresh alcoholic solution of chlorophyll from fresh blue myrtle leaves. It should be applied as soon as the emulsion (collodion) is set, flowed backward and forward for thirty seconds, then the plate is washed in water until smooth, when it is ready for exposure. These plates are quite sensitive to every colour which can be distinguished by the eyes, including the deepest ruby red. By means of these plates and coloured screens I have secured results which you would probably have thought it impossible to secure by any photographic pro cess. I have not been able to secure a chlorophyll solution which would give the same results from any other leaves than those mentioned—“blue myrtle and both leaves and solution must be fresh to secure the greatest degree of sensitiveness. I do not see how it will be possible to employ the chlorophyll successfully with gelatine plates. GLASGOW EXHIBITION. The Glasgow and West of Scotland Amateur Photo graphic Association’sfirst Exhibition was opened on Friday last, for two days. The Association has only been in existence about nine months, and the vigorous life it has developed is shown in a highly creditable exhibition. Too much praise indeed can scarcely be given to the pluck and enthusiasm which have made it possible to bring together in so short a space of time a collection of gems and pretty bits of scenery rarely seen and more rarely photographed by the professional photographer. The number of picturesque glades and glens, of waterfalls and bubbling streams, might well tempt one to babble a page about them, but want of space forbids us to insert more than a list of the awards made, which were as follows ;— Section A.—Class 1.—1st prize, “Chestnut Grove,” A. J. W. Reid; 2nd prize, “ Brig o’ Turk,” Robert Cutting. Class 3.—1st prize, “ A Bit on Loch Katrine,” Edwin Smithells; 2nd prize, “The Smiddy,” T. N. Arm. strong. Class 5.—1st prize, “Baiting the Long Line,” R. Cutting; 2nd prize, “ Hard Times,” A. J. W. Reid. Class 7.—lstprize, “ A Serious Chapter,” Edwin Smithells; 2nd prize, “In the Conservatory,” A. J. W. Reid; “ Gipsies,” J. M. Skinner. Class 9.—lstprize, “A Breezy Day,” T. N. Armstrong. Class 10.—1st prize, “Steamer Gareloch,” Wilfrid Smith. Section B.—Class 2.—1st prize, “ Ben Venue,” Edwin Smithells; 2nd, “ Scarborough,” W. Snell Anderson. Transparency.—1st prize, W. Snell Anderson; 2nd prize, T. N. Armstrong. Best Portrait taken in Open Air.—1st prize, “ In the Corn field,” A. J. W. Reid ; 2nd prize, “ No. 12,” F. W. Verel. Enlargement.—W. Snell Anderson. THE MANCHESTER PHOTOGRAPHIC SOCIETY—PAST, PRESENT, AND FUTURE. BY J. POLLITT.* The newly-appointed Council of this Society, having seen fit to place me in the position of President for the session on which we have j ust now entered, I think I ought not to allow the occasion to pass by without some introductory remarks bearing on what I conceive to bo the part which a well-regulated society such as this may perform in the history of the art-science of photography. From 1839, when the processes of Daguerre and Talbot were first made known, down to 1851, when Archer perfected and published his collodion process, photography was in the hands of a very limited number; but with the advent of the latter pro- • Condensed from a paper communicated to the Manchester Photographic Society.