PHOTOGRAPHIC CAMERAS--OTTEWILL'S REGISTERED DOUBLE-BODIED FOLDING CAMERA, is superior to every other form of Camera, for the Photographic Tourist, from its capability of Elongation or Contraction to any Focal Adjustment, its Portability, and its adaptation for taking either Views or Portraits.--The Trade supplied. Every Description of Camera, or Slides, Tripod Stands, Printings Frames, &c., may be obtained at his MANUFACTORY, Charlotte Terrace, Barnsbury Road, Islington. New Inventions, Models, &c., made to order or from Drawings. * * * * * IMPROVEMENT IN COLLODION.-J. B. HOCKIN CO., Chemists, 289. Strand, have, by an improved mode of Iodizing succeeded in producing a Collodion equal, they may say superior, in sensitiveness and density of Negative, to any other hitherto published; without diminishing the keeping properties and appreciation of half tint for which their manufacture leas been esteemed. Apparatus, pure Chemicals, and all the requirements for the practice of Photography. Instruction in the Art. THE COLLODION AND POSITIVE PAPER PROCESS. By J. B. HOCKIN. Price 1s., per Post, 1s. 2d. * * * * * PHOTOGRAPHY. A COMPLETE SET OF APPARATUS for 4l. 4s., containing an Expanding Camera, with warranted Double Achromatic Adjusting Lenses, a Portable Stand, Pressure Frame, Levelling Stand, and Baths, complete. PORTRAIT LENSES of double Achromatic combination, from 1l. 12s. 6d_._ LANDSCAPE LENSES, with Rack Adjustment, from 25s. A GUIDE to the Practice of this interesting Art, 1s., by post free, 1s. 6d. French Polished MAHOGANY STEREOSCOPES, from 10s. 6d. A large assortment of STEREOSCOPIC PICTURES for the same in Daguerreotype, Calotype, or Albumen, at equally low prices. ACHROMATIC MICROSCOPES. Beautifully finished ACHROMATIC MICROSCOPE, with all the latest improvements and apparatus, complete from 3l. 15s., at C. BAKER'S, Optical and Mathematical Instrument Warehouse, 244. High Holborn (opposite Day & Martin's). * * * * * ALLEN'S ILLUSTRATED CATALOGUE, containing Size, Price and Description of upwards of 100 articles consisting of PORTMANTEAUS, TRAVELLING-BAGS Ladies' Portmanteaus, DESPATCH-BOXES, WRITING-DESKS, DRESSING-CASES and other travelling requisites, Gratis on application or sent free by Post on receipt of Two Stamps. MESSRS. ALLEN'S registered Despatch-box and Writing-desk, their Travelling-bag with the opening as large as the bag, and the new Portmanteau containing four compartments, are undoubtedly the best articles of the kind ever produced. J. W. & T. ALLEN, 18. & 22. West Strand. * * * * *