Make the most DURABLE and ORNAMENTAL ROOF in the world. Send for descriptive circular and new prices to IRON CLAD MANUFACTURING CO., 22 CLIFF STREET, NEW YORK. SHEPARD'S CELEBRATED $50 Screw Cutting Foot Lathe. Foot and Power Lathes, Drill Presses, Scrolls, Circular and Band Saws, Saw Attachments, Chucks, Mandrels, Twist Drills, Dogs, Calipers, etc. Send for catalogue of outfits for amateurs or artisans. H. L. SHEPARD & CO., 331, 333, 335. & 337 West Front Street, Cincinnati, Ohio. WANTED.--FIRST-CLASS PARTIES IN cities to sell Wing's Fan Ventilators. A great success. Rare chance to make money. See SCI. AM., Jan. 31, 1880, or send for pamphlets, etc. L. J. WING, or THE SIMONDS MFG. CO., 50 Cliff Street, New York. CENTENNIAL AND PARIS MEDALS. Mason's Friction Clutches and Elevators. "New and Improved Patterns." VOLNEY W. MASON & CO., Providence, R. I., U. S. A. BROWN'S PAT. SPLIT PULLEYS Shafts, Hangers, At low prices. Largest assortment. A. & F. BROWN, 57, 59, & 61 Lewis St., New York. [Illustration: PROSPECTUS] OF THE SCIENTIFIC AMERICAN FOR 1880. THE MOST POPULAR SCIENTIFIC PAPER IN THE WORLD. * * * * * VOLUME XLIII. NEW SERIES. * * * * * ONLY $3.20 A YEAR, INCLUDING POSTAGE. WEEKLY. 52 NUMBERS A YEAR. * * * * * THIS WIDELY CIRCULATED and splendidly illustrated paper is published weekly. Every number contains sixteen pages of useful information, and a large number of original engravings of new inventions and discoveries, representing Engineering Works, Steam Machinery, New Inventions, Novelties in Mechanics, Manufactures, Chemistry, Electricity, Telegraphy, Photography, Architecture, Agriculture, Horticulture, Natural History, etc. ALL CLASSES OF READERS find in THE SCIENTIFIC AMERICAN a popular _resume_ of the best scientific information of the day; and it is the aim of the publishers to present it in an attractive form, avoiding as much as possible abstruse terms. To every intelligent mind, this journal affords a constant supply of instructive reading. It Is promotive of knowledge and progress in every community where it circulates. TERMS OF SUBSCRIPTION.--One copy of THE SCIENTIFIC AMERICAN will be sent for _one year_--52 numbers--postage prepaid, to any subscriber in the United States or Canada, on receipt of THREE DOLLARS AND TWENTY CENTS by the publishers; six months, $1.60; three months, $1.00. CLUBS.--ONE EXTRA COPY of THE SCIENTIFIC AMERICAN will be supplied gratis _for every club of five subscribers_ at $3.20 each; additional copies at same proportionate rate. Postage prepaid. One copy of THE SCIENTIFIC AMERICAN and one copy of THE SCIENTIFIC AMERICAN SUPPLEMENT will be sent for one year, postage prepaid, to any subscriber in the United States or Canada, on receipt of _seven dollars_ by the publishers.