SOME RECENT TRIUMPHS OF APPLIED SCIENCE The province of electro-chemistry, p. 298--Linking the laboratory with the workshop, p. 299--Soda manufactories at Niagara Falls, p. 300--Producing aluminum by the electrolytic process, p. 300--Old and new methods compared, p. 301--Nitrogen from the air, p. 303--What this discovery means to the food industries of the world, p. 304--Prof. Birkeland's method, p. 307--Another method of nitrogen fixation, p. 309--Cost of production, p. 312--Electrical energy, p. 313--Production of high temperatures with the electric arc, p. 314--The production of artificial diamonds by the explosion of cordite, p. 315--Industrial problems of to-day and to-morrow, p. 316. ILLUSTRATIONS A PRIMITIVE USE OF THE ANIMAL MACHINE THAT IS STILL IN VOGUE IN MANY EUROPEAN COUNTRIES _Frontispiece_ HORSE AND CATTLE POWER _Facing p._ 32 CRANES AND DERRICKS " 38 A BELGIAN MILK-WAGON " 56 TWO APPARATUSES FOR THE UTILIZATION OF ANIMAL POWER " 60 WINDMILLS OF ANCIENT AND MODERN TYPES " 68 WATER WHEELS " 72 HYDRAULIC PRESS AND HYDRAULIC CAPSTAN " 76 THOMAS SAVERY'S STEAM ENGINE " 86 DIAGRAMS OF EARLY ATTEMPTS TO UTILIZE THE POWER OF STEAM " 88 A MODEL OF THE NEWCOMEN ENGINE " 92 WATT'S EARLIEST TYPE OF PUMPING-ENGINE " 96 WATT'S ROTATIVE ENGINE " 100 JAMES WATT " 108 OLD IDEAS AND NEW APPLIED TO BOILER CONSTRUCTION " 114 COMPOUND ENGINES " 118 ROTARY ENGINES " 122 THE ORIGINAL PARSONS' TURBINE ENGINE AND THE RECORD-BREAKING SHIP FOR WHICH IT IS RESPONSIBLE " 128 GAS AND OIL ENGINES " 136 AN ELECTRIC TRAIN AND THE DYNAMO THAT PROPELS IT " 174 WILDE'S SEPARATELY EXCITED DYNAMO " 178 THE EVOLUTION OF THE DYNAMO " 180 VIEW IN ONE OF THE POWER HOUSES AT NIAGARA " 186 ELECTRICAL TRANSFORMERS " 198 THOMAS A. EDISON AND THE DYNAMO THAT GENERATED THE FIRST COMMERCIAL INCANDESCENT LIGHT " 228 A FLINT-AND-STEEL OUTFIT, AND A MINER'S STEEL MILL " 248 THE LOCOMOTIVE "PUFFING BILLY" AND A MODERN COLLIERY TROLLEY " 258 THE CONQUEST OF NATURE