Saccardo System of Ventilation, 330 Saunders, W. L., 88 Seepage Water, 191 Seine River Tunnel, 293 Setting up Centers, 70 Severn Tunnel, 221 Shafts, Description of, 40 Shaler, Ira A., 142 Shield and Compressed Air Method, 263 Shield Construction: Diaphragm, 256 Cellular Division, 255 Dimensions of Shields, 259 Front End, 254 General Form, 252 Rear End, 257 Shell, 253 Shield Method: Barlow Shield, 242 Beach’s Shield, 245 Blackwall Tunnel Shield, 248 Brunel Shield, 240 City and South London Railway Shield, 250 Greathead’s Shield, 245 History, 238 Prelini’s Shield, 251 St. Clair River Tunnel Shield, 247 Side Shafts, 41 Side Tunnels Lining, 79 Side Walls Lining, 77 Simplon Tunnel, 103 Soils Encountered in Tunnels, 3 Sonnstein Tunnel, 99 Stations of Subways, 207-216 St. Clair River Tunnel Shield, 247 St. Gothard Tunnel, 132 Steam Power Plant, 85 Stratification of the Soils, 6 Strickler Tunnel, 96 Striking the Centers, 71 Strutting: American Method, 174 Austrian Method, 177 Belgian Method, 146 Dimensions of Timber, 54 English Method, 167 Fort George Tunnel, 137 Full Section, 51 German Method, 156 Headings, 48 Italian Method, 183 Murray Hill Tunnel, 125 Pilot Method, 193 Quantity of Timber, 54 Shafts, 52 Iron: Full Section, 56 Headings, 56 Shafts, 57 Submarine Tunneling: Cofferdam Method, 281 Compressed Air Method, 225 Detroit River Tunnel, 296 General Discussion, 218 Harlem River Tunnel, 285 Hudson River Tunnel Pennsylvania Railroad, 269 Lining, 261 Milwaukee Water-Works Tunnel, 226 Pneumatic Caisson Method, 284 Seine River Tunnel, 293 Severn Tunnel, 221 Shield and Compressed Air Method, 263 Shield System, 238 Sinking and Joining Sections Built on Land, 293 Van Buren Street Tunnel, 282 Subways: Boston, 203 Cost of, 209-217 Cross-sections, 204-211 General Discussion, 195-202 Lining, 207-213 New York Rapid Transit Railway, 209 Stations, 207-216 Sutro, Adolph, 330