CULTIVATOR TEETH.—Charles H. Sayre and George Klinck, Utica, N. Y. have applied for an extension of the above patent. Day ofhearing .Jan. 26,1&70. MANUFACTURE OF IIWN AND STEEL,-Henry Bessemer, of London, England, has petitioned for the extension of the above patent. Day of hearing:. Jan. 20, 1870. GEARING FOR FEED ROLLERS OF PLANING MACHINES.—Charles Burleiglr, Georgtown, Colorado Territory, has applied for an extension of the above patent. Day of hearing, January 26,18rt0. REFINING IRON.-Christian Shunir, Philadelphia, Pa., has applied for an extension of the above patent. Day of hearing Jan. 26,1870. SEALING PRESERVE CANS .—R. H, Lewis .Sacramento , Cal . , has petitioned for an extension of the Caveats are desirable ifan inventor is not fully prepared to apply for his patent. A Caveat affords protection for one ye!tr against the issue ofa patent to another for the same invention. Patent fee on filing a Caveat, $10. Agency charge for preparing and filing the documents from $10 to $12. Address MUNN&CO., 37 Park Row, New York. Inventions Examined at the Patent Omce.—Inventors can have careful search made at the Patent Office into the novelty of their inventions, and receive a report in writing as to the probable success of an application. Send sketch and description by mail, inclosing fee of $5' Address MUNN&CO., 37 Park Row, New York. CITY SUBSCRIBERS.—The SCIENTIFIC AMERICAN will be delivered in every par tof the city at $3'50 a year. Single copies for sale at a >lthe News Stands ilil this city, Brooklyn, Jersey City, and Williamsburg, and by most of the News Dealers in the Umted States. SUBSCRIBERS—who wish to have their volumes bound, can send them to this office. The charge for binding is $1.50 per volume. The amount should be remitted in advance, and the volumes will be sent as soon as they are bound. RECEIPTS—When money is paid at the office for neib wh subscribers remit their money by mail,they may consider the arrival of the first paper a bonafide acknowl- ed2:ment of their funds.