Transverse Section of Pneumatic Caisson 71 Pier of Hawkesbury Bridge, Australia 75 Foundation Crib of the Poughkeepsie Bridge 76 Transverse Section of the Same 76 Granite Arched Approach to Harlem River Bridge in Process of Construction 77 The Old Portage Viaduct, Erie Railway, N. Y. 78 The New Portage Viaduct 79 The Britannia Tubular Bridge over the Menai Straits, North Wales 80 Old Stone Towers of the Niagara Suspension Bridge 82 The New Iron Towers of the Same 82 Truss Bridge of the Northern Pacific Railway over the Missouri River at Bismarck, Dak.--Testing the Central Span 87 Curved Viaduct, Georgetown, Col.; the Union Pacific Crossing its own Line 88 The Niagara Cantilever Bridge in Progress 90 The Niagara Cantilever Bridge Completed 91 The Lachine Bridge, on the Canadian Pacific Railway, near Montreal, Canada 92 The 510-feet Span Steel Arches of the New Harlem River Bridge, New York, during Construction 97 London Underground Railway Station 98 Conestoga Wagon and Team 101 Baltimore & Ohio Railroad, 1830-35 101 Boston & Worcester Railroad, 1835 102 Horatio Allen 103 Peter Cooper's Locomotive, 1830 104 "South Carolina," 1831, and Plan of its Running Gear 105 The "De Witt Clinton," 1831 105 "Grasshopper" Locomotive 106 The "Planet" 107 John B. Jervis's Locomotive, 1831, and Plan of its Running Gear 108 Campbell's Locomotive 109 Locomotive for Suburban Traffic 110 Locomotive for Street Railway 110 Four-wheeled Switching Locomotive 113 Driving Wheels, Frames, Spurs, etc., of American Locomotive 114 Longitudinal Section of a Locomotive Boiler 115 Transverse Section 115 Rudimentary Injector 116