Hoopes & Townsend .New York...... Lewis Oliver & Phillips, H. B. Newhall, Agent, New York. Miller & Smith.... New Haven Nut Co... Lock, Nut & Bolt Co. of New York........ O. W. Child Phillipsburg Manufacturing Co.... Pittsburgh Bolt Co...... Pratt & Co..... Nickle. Nuts, &c. 166 Pittsburgh, Pa... 118 132 Providence Tool Co., H. B. Newhall, Agent......New York... Agent... Rhode Island Nut Co., H. B. Newhall, Agent....New York..... .Philadelphia, Pa.. Wm. H. Haskell & Co., H. B. Newhall, Agent...New York.. WHEEL GEARING-CONTINUED. TEETH OF WHEELS-CAST-IRON. (Molesworth.) Table showing the Horse-Power that may be transmitted by each Inch of Breadth of Tooth, with different Velocities and Pitches. PITCHES OF EQUIVALENT STRENGTH FOR THE TEETH OF WHEELS IN DIFFEREMT GRAFF TUBE WORKS. WILLIAM GRAFF & CO. MANUFACTURERS OF PLAIN AND GALVANIZED WROUGHT IRON PIPE, FOR GAS, STEAM, WATER, OIL, &c. PF &I, VC, & XV CIRON, FISH PLATES, TRACK BOLTS, R. R. CAR and LOCOMOTIVE AXLES, RAILROAD, STEAMBOAT and MACHINE FORGINGS. Office, 358 Penn St., Pittsburgh, Pa. W. W. Snow's Patent, for Inside or Outside Bearings. 36 in. diameter...... Extra heavy, for Engine Trucks......... 66 Engines, Tenders, and Passenger Cars ......Extra heavy, for Engine Trucks.. .Engines, Tenders, and Cars..... 33 in. 33 in. 30 in. PLUMB, BURDICT & BARNARD, BUFFALO, N. Y. MANUFACTURERS OF BOLTS. COACH SCREWS, SKEIN BOLTS, PATENT Diamond Neck Carriage Bolts TIRE, SLEIGH SHOE, Machine and Blank Bolts. Nuts, Hot & Cold Pressed. Providence Tool Co.; H. B. Newhall, Agent.....New York.... See Page 166 Pa....... Philadelphia, Pa............See Page 80 .New York 168 .See Page 112 Office Chairs. ..Chicago, Ill.. .See Page 206 ..Chicago, Ill... .See Page 206 160 Office Furniture. Buffalo, N. Y.............. Oil Cabinets. Philadelphia, Pa............See Page 246 Nitric acid will produce a black spot on steel; the darker the spot the harder the steel. Iron, on the contrary, remains bright if touched with nitric acid. Good steel in its soft state has a curved fracture and a uniform grey lustre; in its hard state a dull, silvery, uniform white. Cracks, threads, or sparkling particles denote bad quality. Good steel will not bear a white heat without falling to pieces, and will crumble under the hammer at a bright red heat, while at a middling heat it may be drawn out under the hammer to a fine point. Care should be taken that before attempting to draw it out to a point, the fracture is not concave, and should it be so the end should be filed to an obtuse point before operating. Steel should be drawn out to a fine point and plunged into colp water; the fractured point should scratch glass. To test its toughness, place a fragment on a block of cast iron; if good it may be driven by the blow of a hammer into the cast-iron, if poor it will crush under the blow. A soft, tough iron, if broken gradually, gives long silky fibres of leaden-grey hue, which twist together and cohere before breaking. A medium even grain with fibres denotes good iron. Badly refined iron gives a short blackish fibre on fracture. A very fine grain denotes hard steely iron, likely to be cold-short and hard. Coarse grain with bright crystallized fracture or discoloured spots denotes coldshort, brittle iron, which works easily when heated and welds well. Cracks on the edge of a bar are indications of hot-short iron. Good iron is readily heated, is soft under the hammer, and throws out few sparks. |