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, Printing 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 has been esteemed. Apparatus, pure Chemicals, and all the requirements for the practice of Photography. Instruction in the Art. * * * * * PHOTOGRAPHIC INSTITUTION.--An EXHIBITION of PICTURES, by the most celebrated French, Italian, and English Photographers, embracing Views of the principal Countries and Cities of Europe, is now OPEN. Admission 6d. A Portrait taken by MR. TALBOT'S Patent Process, One Guinea; Three extra Copies for 10s. PHOTOGRAPHIC INSTITUTION, 168. NEW BOND STREET. * * * * * HAMILTON'S MODERN INSTRUCTIONS FOR SINGING. 5s. HAMILTON'S MODERN INSTRUCTIONS FOR THE PIANOFORTE. Forty-sixth Edition. 4s. HAMILTON'S DICTIONARY OF 3500 MUSICAL TERMS. Forty-second Edition. 1s. CLARKE'S CATECHISM OF THE RUDIMENTS OF MUSIC. Thirtieth Edition. 1s. "These works are all favorites with professors, because they are favourites with the pupils. Few know how to write a book of instruction; but Hamilton did, because he knew thoroughly well how to teach. The extreme popularity of these works (as may be noticed from the number of editions they have passed through) has called forth many imitations; but everybody will like the original, or prototype, rather than the copy. The Dictionary is famous as the most copious and correct extant; and the little catechism is as clever as it is unpretentious."--Vide _Reading Mercury_, Oct. 22. ROBERT COCKS & CO., New Burlington Street, London. * * * * * Library of an eminent Scholar.--Six Days' Sale.