THE STUDY OF MACHINERY AND SKETCHING.--Various applications and combinations: The Sketching of Machinery. Drilling Machines; Motive Machines; Water wheels. Construction and Setting up of water wheels. Delineation of water wheels. Design of a water wheel. Sketch of a water wheel. Overshot water wheels. Water Pumps; Steam Motors; High-pressure expansive steam engine. Details of Construction; Movements of the Distribution and Expansion Valves; Rules and Practical Data. OBLIQUE PROJECTIONS. PARALLEL PERSPECTIVE. TRUE PERSPECTIVE.--Elementary principles. Applications--flour mill driven by belts. Description of the mill. Representation of the mill in perspective. EXAMPLES OF FINISHED DRAWINGS OF MACHINERY. [Symbol: Right index] The above, or any of our Books, sent by mail, free of postage, at the publication price. Our new and enlarged CATALOGUE OF PRACTICAL AND SCIENTIFIC BOOKS--96 pages, 8vo.--sent free to any one who will furnish his address. HENRY CAREY BAIRD & CO., INDUSTRIAL PUBLISHERS and BOOKSELLERS, 810 Walnut Street, Philadelphia. * * * * * STEAM PUMPS. HENRY R. WORTHINGTON, 239 Broadway, N. Y. 83 Water St., Boston. THE WORTHINGTON DUPLEX PUMPING ENGINES FOR WATER WORKS--Compound, Condensing or Non-Condensing. Used in over 100 Water-Works Stations. STEAM PUMPS--Duplex and Single Cylinder. PRICE LIST ISSUED JAN. 1, 1879, WITH A REDUCTION EXCEEDING 30 PER CENT. WATER METERS. OIL METERS. * * * * * [Illustration: Truss] THIS NEW ELASTIC TRUSS Has a Pad differing from all others, is cup-shape, with Self-Adjusting Ball in center, adapts itself to all positions of the body, while the BALL in the cup PRESSES BACK the INTESTINES JUST AS A PERSON WOULD WITH THE FINGER. With light pressure the Hernia is held securely day and night, and a radical cure certain. It is easy, durable and cheap. Sent by mail. Circulars free. EGGLESTON TRUSS CO., CHICAGO, ILL. * * * * * THE HANCOCK INSPIRATOR TESTIMONIALS. OFFICE OF THE HANCOCK INSP. CO., LONDON, ENG., Feb. 11, 1879. I have just received an order from the English Government for 22 Number 15 Inspirators--making 24 machines in all for the Government this month. B. H. WARREN, Agent. * * * * * OFFICE OF H. S. MANNING & CO., 111 Liberty St., NEW YORK, Feb. 26, 1879. GENTLEMEN: We have authority from Mr. Martin, Chief Engineer Union Ferry Co., Brooklyn, to state that they have 17 Inspirators at work on 17 of their boats, feeding their main boilers, and all giving satisfaction, and to refer any one to him. Yours truly, H. S. MANNING & CO., Agents. [Symbol: Right index] ILLUSTRATED AND DESCRIPTIVE CIRCULARS SENT ON APPLICATION TO HANCOCK INSPIRATOR CO., 52 CENTRAL WHARF, BOSTON. * * * * * [Illustration: Corrugated Iron] THIS NEW MOSELEY IRON BRIDGE AND ROOF CO. CORRUGATED IRON