viii CONTENTS OF VOLUME II. 



MISCELLANEOUS SUBJECTS. 



PAGIB 



ON THE USE OP CLAY RETORTS FOR GAS-MAKING .... 297 



MACHINERY FOR MINING PURPOSES 298 



ON THE CONSTRUCTION OF ARTILLERY. &c 299, 402 



ON RAILWAY ACCIDENTS 302 



THE RELATIVE ADVANTAGES OF THE INCH AND METRE AS THE 



STANDARD UNIT OF DECIMAL MEASURE 305 



PERMANENT WAY . 307,415 



PRESERVATION OF IRON SHIPS BY ZINC SHEATHING . . . . 308 



OPTICAL APPARATUS FOR LIGHTHOUSES 311 



THE STRENGTH AND RESISTANCE OF MATERIALS . . . . 315 



ARTIFICIAL PRODUCTION OF COLD 317. 324 



PNEUMATIC DESPATCH TUBES ; THE CIRCUIT SYSTEM . . . 319 



THE ABA-EL-WAKF SUGAR FACTORY 320 



ON GUN CARRIAGES FOR HEAVY ORDNANCE . . . . . 330 



RAILWAY SIGNALS 332 



DEEP SEA SOUNDING BY PIANOFORTE WIRE . . . . . 333 



COMPRESSED AIR MACHINERY FOR UNDERGROUND HAULAGE . 335 



THE IRON ORES OF SWEDEN 337 



THE HELICAL PUMP . . 339 



THE EXPEDIENCY OF PROTECTION FOR INVENTIONS . . . 341 



ON GUNS . . . ' 343 



ON THE PATENT LAWS 344, 414, 418 



ON PNEUMATIC TRANSMISSION 346 



VENTILATION AND WORKING OF RAILWAY TUNNELS . . . 356 



ON THE CHALK WATER SYSTEM 385 



ON THE TRANSMISSION OF POWER TO DISTANCES .... 386 



ON DESIGNING LARGE IRON RAILWAY BRIDGES . . . . 397 



ON ARMOUR TO RESIST SHOT AND SHELL 400 



ON CHANGES IN IRON AND STEEL AT HIGH TEMPERATURES . . 408 



ON THE PHOTOPHONE 410 



ON GIEDER BRIDGES 412 



ON THE FORCE OF RECOIL FOR GUN CARRIAGES . 417 



