The Cunard liner "Lusitania " has been designed for a speed of 25 knots an hour, a speed which is a knot and a half in excess of that of the fastest of the existing ocean greyhounds the "Kaiser Wilhelm II," of the North German Lloyd. To propel the great hull through the water at this speed the Lustania " is provided with turbine engines developing 63.000 indicated horse power, and driving four screws. The turbines are the largest so far constructed for similar woik. The low pressure engines alone weigh nearly 430 tons. The diameter of the rotor of the latter is 16 ft. 8 in., the blades having a maximum length of 12 in. toward the low pressure end, giving a maximum diameter of the rotor of 19 ft. 4 in. The peripheral speed of the rotor under normal conditions of working will attain a maximum of 142 ft. a second. The engines have been designed with the greatest care, an 1 in them have been incorporated the latest advance in turbine construction. Especially is this true of the casings, which have been carefully proportioned to resist circumferential stress without undue weight. By the use of the turbine, and by great increase in displacement, it has been possible to add enormously to the engine power in order to obtain the increase in speed, though this is comparatively slight in itself.