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JUXE 27,1862.] THE PHOTOGRAPHIC NEWS. 311 a % 2 ’X 36 0 pt, ;o® 1 b, o fv 08,a ) fo‘ 0‘dd‘ 16., edf W‘ Xi q0®. gos0 §bilv 5 2 3, o2 dt ‘gtP io", et‘ to"® g0" fe 1>W , rP ga0, e Ee „ e 1 s ichadj godb” ad jlo s0e j"a e,e jd f )o02• ,02 gte I therefore suppose I am working with Mr. Vernon Heath’s apparatus,, taking such for my foundation, and applying my own experience to the matter, I must say that the 41 lens of Ross, which 1 have, gives, up to 8}x6], very fair and satis factory results. Not having had an opportunity of trying any other lens, I cannot say more, but even up to that size, to get depth and perfect sharpness over every part of the picture, a very much smaller stop must be used than that usually sent out with the lens. I use one an eighth of an inch, and expose in full sunshine seven minutes. Having been frequently applied to since March to enlarge cartes de visite heads to life size, I set about thinking whether the lens (4} focal length) I was then working with would answer my purpose; upon instituting experiments thereon, I found it did so, but in order to secure definition I lost much light. I therefore applied to Mr. Ross for assist- Ance, hut without avail; I next got a triplet from Mr. Dall- Meyer, still the same fault, although considerably modified. At last I went back to the old original lens of all, and Mcceeded. I am therefore making arrangements to enlarge Wes de visite pictures to 15 x 12 so that every portion of the Mire shall be etpially sharp, full of h al f tone, and the general ect satisfactory. Your advertising columns will inform * public when 1 am in this position. Many of your readers have by this time seen, from the t: P«rts of the various journals, the doings of the Photo- Eraphic Society at its last meeting. M. Claudet did certainly Ov us that the solar camera could distort a head larger "an life; hut he failed to convince many others besides "self that his image was equally sharp all over the focus- "gscreen. And, supposing that in the place of a paper psitive, as the final results of the operations of the solar Sinera, a negative by a second operation is produced, what m"3Portion of sharpness, let me ask you, Mr. Editor, would M bear to the original negative, when in the enlarged Ftive the present results are so dreadfully indistinct ? 1 am prepared to construct an apparatus, without much expense, that shall enlarge to the same extent as the camera, and yet give perfect and equal definition all nersthe plate. Whether the demands of the public may u .’7 me in carrying out these ideas is another matter; it p r them to decide—for me to follow. I have not yet done with the matter. I believe it 10 yb found that to enlarge a small picture well, up to 1 8 and over, long-focus lenses of large diameters will Bately carry the day, as the rays of light, having to 615 further, lose much of their intensity after having 6 through a short-focus lens of small aperture, and in onhtence the exposure is considerably lengthened; while Ben" other hand, if a long-focus lens of large aperture ik^cd, the rays, although having to travel the same t6"ce in proportion, are strengthened, or made equivalent distance, by the larger refracting surfaces derived Or’he greater diameters of the lenses. p t| the many lenses offered to the photographers of the Mtk' day, there is none that gives better results than the haP Eraphic > it maybe used in a confined space, and it apertpsatilted, and it gives good definition with the whole forture,especially in interiors, and, were it not for its un- BovldAtely giving pictures of a pincushion formation, it I hav, 26 a very valuable lens. Whether the triplet of which this I SPoken does otherwise, I am not prepared to say, but Bue dimay. state, that it will take a landscape 10 X 8 with- diaphs ortion and without using by any means the smallest Qipee sm8m. It will also take a head life-size (see enclosed) I kyt, anath: ® camera. It will copy without reduction of sub- i tiapl will give both texture and water-marks without any inragmat all in letter Paper. Nantganstision, I would add, that as I am guided by the eyer,orwishesof the public, that if Mr. Hoss, Mr. Dall- Ereatera. rAnybody-else, will make a lens that will offer "nglish yintages than those of the present two celebrated “ ci's, I for one will be happy to be a purchaser, and will strive to make the lens committed to my care tell its fullest capabilities to “ a discerning public.” Apologizing for the space I have occupied, I am, dear sir, yours truly, W. H. Warner, Hoss. Ahotograpkir Zlotes aud Queries. Mr. Sutton’s Quick Dry Process. Sib—I have been trying Mr. Sutton’s rapid Taupenot pro cess, but found no increase of sensibility. Would you be kind enough to inform me if I have made any error in the manipu lation? I used Keene’s dry process collodion, sensitized in a 40- grain bath faintly acid, washed thoroughly, poured over the albumen solution, drained, and then dried before a bright fire, making the plate quite hot; when cool, 1 immersed it for half a minute in a 20-grain bath, and finally washed in a 10-grain bath, both acidified with 1 drop of acetic to the ounce, but without any iodide of potass, like the first bath. After all this trouble the plates were not to be compared to the honey and tannin I made according to the formula given by you in No. 192, either in sensibility, smoothness of the film, or keeping qualities. It may be my inexperience, but I shall be sorry if I have made two extra baths of no use to me.—Yours very truly, BLUNDELEUS. [We have not experimented ourselves with Mr. Sutton’s quick process. We know him to be, however, a very careful experimentalist, and a thoroughly good, practical photographer, and he has, doubtless, produced the results he describes. Pro bably your bath may require a little more acid. To give the process the utmost fair play, it would be well to try some of his collodion with it. In our own hands the honey and tannin has proved the best dry process we have tried. We are glad to hear your favourable account of it.—Ed.] Rapid Dry Plates. Sib,—In a late number of your very valuable journal I observed some enquiries from Mr. Taylor and yourself regard ing Mr. Louis Floyd’s instantaneous dry plates. That gentle man having accepted an appointment in Russia, I do not know whether or not I might be justified in imparting his modus operandi through your columns, he having given me his formula some time since; but from a variety of circumstances 1 have not yet been able to try it. I have put myself in communica tion with him, and should ho give his permission I will send you the details as soon as I have tried the system. I think it will bo no breach of confidence to state that it is a slight modi fication of the Hill Norris formula, and totally distinct from Mr. Sutton’s method. The instantaneous effects are caused by moistening the plates previous to exposure with a solution, but they require to be developed within twelve hours after, other wise stains result.—Yours, &c., Thomas D. Bell. Windermere, Monday, June 22, 1862. liscellaneous. A New Cement of Vabied Use.—New uses have been suggested for a combination of pitch and gutta-percha, as to which we some years since gave instructions for the prevention of damp in walls. Professor Edmund Davy has read a paper to the Royal Dublin Society on the subject. He obtains the cement much as wo suggested, by melting together in an iron vessel two parts by weight of common pitch. with one part of gutta-percha. It forms a homogeneous fluid, which is much more manageable for many useful purposes than gutta-percha alone, and which after being poured into cold water, may bo easily wiped dry and kept for use. The cement adheres with the greatest tenacity to wood, stones, glass, porcelain, ivory, leather, parchment, paper, hair, feathers, silk, woollen, cotton, linen fabrics, &c. It is well adapted for glazing windows, and as a cement for aquariums.—Builder.
