An Account of Experiments made by a Board of United States Naval Engineers with Screw Propellers of Different Material and Dimensions, applied to the United States Fish Commission's Steamer "Lookout," with the Hull Coppered and not Coppered. By Chief Engineer Isherwood, U. S. Navy... 81 C. B. Dudley on the "Wearing Capacity of Steel Rails in Relation to their Chemical Composition and Physical Properties," and of A. L. Holley on Rail Patterns," at the Philadelphia Meeting of the American Institute of Mining Engineers, held at the Franklin Institute, February 17, 1881...... Boiler Explosion at Gaffney & Co.'s Dye Works, Philadelphia, June 1, 1881. By W. Barnet Le Van Radio-Dynamics By Pliny Earle Chase, LL.D.. The Properties of Air relating to Ventilation and Heating. By Robert Briggs, CE Pronunciation of Foreign Languages, 118. Applications of Electricity, 153. Decomposition of Chinese Magnetic 156 HOWSON & SON'S OFFICES FOR PROCURING United States and Foreign Patents AND PROSECUTING PATENT CAUSES. HENRY HOWSON, Engineer and Solicitor of Patents. CHARLES HOWSON, Attorney-at-Law and Counsel in Patent Cases. Principal Office, 119 South Fourth Street, Philadelphia. Branch Office, 605 Seventh St., Washington, D.C. Authors of "The American Patent System," "Our Country's Debt to Patents," "Answers to Questions of the State Department Relating to Patents." Also, of a "Brief Treatise on Patents," published by Porter & Coates. RUDOLPH M. HUNTER, M.E., C.E., CONSULTING ENGINEER AND SOLICITOR UNITED STATES & FOREIGN PATENTS Expert in the Trial of Patent Causes. Machinery Designed and Working Drawings Prepared. Examinations in regard to the validity and Infringement of Patents. REJECTED CASES A SPECIALTY. Main Offices, 901 Walnut Street, Bend for illustrated book on Patents, free. Jan. '81 ly PHILADELPHIA. SUGAR APPARATUS. Cane Mills, Defecators, Single, Double or Triple GAS APPARATUS. Morton Patent Self-Sealing Mouth Pieces and ROTARY FANS. For Ventilation of Buildings and Mines. HYDRAULIC ELEVATORS. For Passenger or Freight Service, of improved construction, combining economy of space occupied and power used, june '81 6m WATER-TUBE STEAM BOILER Centennial Exposition Medal awarded this Boiler for Highest Economy and Efficiency on Test. The following are a few of the parties having these Boilers in use in large lots: 3441 H. P. 3790 Singer Manufacturing Company, New York, 19 orders, 3500 Brooklyn Sugar Refining Company, Brooklyn, 2 orders, 1500 500 M. Grambrill & Co., Cotton Mills, Wilmington, Del., The Jessup & Moore Paper Co., Wilmington, Del., 3 orders 1350 500 South Bend Iron Works, South Bend, Ind., 2 orders, U. S. Electric Light Company, New York, 3 orders, And hundreds of others in all kinds of business from 50 to 1000 H. P. each. Illustrated Circulars and other information desired furnished promptly. The Babcock & Wilcox Co. 48 S. Canal St., Chicago. june '81 ly 32 N. 5th St., Philad'a. 30 CORTLANDT ST., NEW YORK. |