FOR ALL KINDS OF ROCK DRILLING, Mining, Quarrying, Tunneling, Railroad Grading, Well Boring, Prospecting, etc. Fifty to Seventy-five per cent of cost and time of hand labor saved. "Test Cores," in form of solid cylinders of rock or mineral taken out of mines from any depth not exceeding one thousand feet, showing true value, stratification, etc. No percussion. Never require sharpening. FIRST PREMIUMS awarded in both American and Europe. Illustrated Circulars sent on application. Beware of infringements. SEVERANCE & HOLT, Proprietors and Manufacturers, Office 16 Wall st., New York. * * * * * _NICKEL PLATING._ BEARDSLEE NICKEL AND MANUFACTURING CO., 82 AND 84 FULTON ST., BROOKLYN, N. Y. RIGHTS sold for the use of, and instruction given in the best method of Nickel Plating. An experience of twelve years enables us to offer a solution and apparatus that remain practically unchanged for years, in constant use. FIRST PREMIUM AWARDED us by the AMERICAN INSTITUTE in 1870. Critical examination of our work solicited. All goods sent to our Factory will meet with prompt attention. New York Office--4 DEV ST., ROOM 2. * * * * * [Illustration] BEST DAMPER REGULATOR for Steam Boiler. Send for Circulars. Agents wanted. MURRILL & KEIZER, Baltimore, Md. * * * * * PAT. SOLID EMERY WHEELS AND OIL STONES, for Brass and Iron Work, Saw Mills, and Edge Tools. Northampton Emery Wheel Co., Leeds, Mass. * * * * * NO LIVE MECHANIC Can afford to be without some of BAIRD'S BOOKS FOR PRACTICAL MEN. My new and enlarged Catalogue of PRACTICAL AND SCIENTIFIC BOOKS, 82 pages, 8vo., will be sent, free of postage, to any one who will favor me with his address. HENRY CAREY BAIRD, Industrial Publisher, 406 Walnut St., PHILADELPHIA. * * * * * THE FIFTH GRAND STATE FAIR OF THE MECHANICS AND AGRICULTURAL STATE ASSOCIATION OF LOUISIANA Will be held on the Fair Grounds of the Association, in the city of New Orleans, commencing SATURDAY, APRIL 8, 1871, and continuing nine days. Exhibitors are invited from every section of America. Railroads, steamships, and other transportation lines, as named in the Premium Catalogues, will carry exhibitors and their wares to and from the Fair at one half the usual rates. For further information see Premium Catalogue, which will be sent to any address free of charge. LUTHER HOMES, Secretary and Treasurer, New Orleans, La. * * * * * [Illustration] ROOT'S SAFETY BOILER. For Pamphlets with Price List and Testimonials, address ROOT STEAM ENGINE CO,, 2d Ave., cor. 28th st., N. Y. THE BEST IN THE MARKET. * * * * * _WIRE ROPE._ JOHN A. ROEBLING'S SONS, MANUFACTURERS, TRENTON, N. J.