400-H.P. AT A.T. STEWART'S. 437-H.P. AT JERSEY CITY SUGAR REFINERY, and over 1,000 boilers in other places. Harrison Boiler Works, Philadelphia. _John A. Coleman, Ag't_, 49 Murray St., N. Y., and 36 Kilby St., Boston. * * * * * _30-H. Corliss Engine_. Also, Six Engines, from 15 to 30-Horse. Have been in use, but are in good order. Cheap for cash. Address CHAS. H. SMITH, 135 North 3d st., Philadelphia, Pa. * * * * * _Drawing Materials_. WHATMAN'S PAPERS.--White and Yellow Roll Drawing Paper, 40 and 54 inches wide Tracing Muslin, Tracing Paper. Muslin-backed Drawing Paper, 40 and 53 inches wide. Winsor & Newton's Colors India Ink. Faber's Drawing Pencils, etc., etc. Priced catalogues 10 cents each. JAS. W. QUEEN & CO., 924 Chestnut st. Philadelphia. * * * * * SAWS. EVERY DESCIPTION Guaranteed under a forfeiture of $1000, to cut the most lumber with the least expense. _Henry Disston & Son_, PHILADELPHIA. Special attention paid to our new style Circular, Belt, Cross-cut, Mill and Hack Saws. Orders received from England, Ireland, and the Continent. * * * * * THE Scientific American FOR 1870 Cash Prize and Premium List This Illustrated Weekly Journal of Practical Information, Art, Science, Mechanics, Invention, Chemistry, and Manufactures--Entered its Twenty-fifth Year on the 1st of January. The SCIENTIFIC AMERICAN stands at the head of Industrial Journals of the world in point of Circulation and Influence. Every number has Sixteen Imperial pages, embellished with Engravings of New Inventions, Machinery, Tools for the Workshop, House, and Farm, also Public Buildings, Dwelling Houses, and Engineering Works. The Illustrated Department of the SCIENTIFIC AMERICAN is a very striking feature, and has elicited the praise of the Press and all articles appearing in its columns are written in a popular and instructive style. To Inventors and Mechanics the SCIENTIFIC AMERICAN has special value and interest, from the fact that it furnishes an Official List of Patents issued, with copious notes of the principal American and European Patents. The Publishers offer the following SCHEDULE OF CASH PRIZES. For the fifteen largest lists of names sent in before February 10, 1870, the following Cash Prizes will be given: $300 FOR THE FIRST LIST. 250 " SECOND LIST. 200 " THIRD LIST. 150 " FOURTH LIST. 100 " FIFTH LIST. 90 " SIXTH LIST. 80 " SEVENTH LIST 70 " EIGHTH LIST. 60 " NINTH LIST. 50 " TENTH LIST. 40 " ELEVENTH LIST. 35 " TWELFTH LIST. 30 " THIRTEENTH LIST. 25 " FOURTEENTH LIST. 20 " FIFTEENTH LIST.