THE VIKING’S CRAFT AND THE MODERN “GREYHOUND”—PROBLEMS OF INERTIA AND RESISTANCE—PRIMARY CONDITION FOR HIGH SPEED—WHAT IS MEANT BY “COEFFICIENT OF FINENESS” AND “INDICATED HORSE-POWER”—ADVANCE IN ECONOMICAL ENGINES—WHAT THE COMPOUND ENGINE EFFECTED—A COMPARISON OF FAST STEAMERS FROM 1836 TO 1890—PREJUDICE AGAINST PROPELLERS AND HIGH PRESSURES—ADVANTAGES OF MORE THAN ONE SCREW PROPELLER—ATTEMPTS AT PROPULSION BY TURBINE WHEELS, EJECTIONS, AND PUMPS—THE INTRODUCTION OF SIEMENS-MARTIN STEEL IN 1875 THE CHIEF FACTOR IN THE SUCCESS OF MODERN FAST STEAMERS—DECREASE IN COAL CONSUMPTION—IMPORTANCE OF FORCED DRAUGHTS—THE PROBLEM OF MECHANICAL STOKING—POSSIBILITIES OF LIQUID FUEL—IS THE PRESENT SPEED LIKELY TO BE INCREASED? From the earliest days the question of the speed of ships has been one of interest to those associated with nautical matters, both from its commercial value, its value in times of emergency, and its forming the chief attraction of a pastime common to all maritime nations. There is no doubt that the emulation excited by the yacht-race of to-day does not exceed that of the ancients in their galley races. The skill of the naval architect is always more or less directed to getting the best possible speed permitted by the other conditions imposed upon him in the designing of ships of all classes, and his reputation has been, and is to-day, perhaps, more dependent on this than on any other subject connected with his profession. To-day he is faced with a competition that did not exist in the past, and his ears are constantly assailed by the cry for higher speed; and whereas a few years ago it was a common impression that the maximum limit had been reached, we have witnessed, during the past three or four years, performances by ships, both large and small, of speeds then undreamed of. It is quite true that there has existed in the minds of visionaries, whose chief occupation is to add to the receipts of the patent offices, speeds even beyond those now attained, and although it is possible that some of their predictions may be verified, it is at the same time certain that success will not be achieved by the means suggested by these gentlemen. It is common experience with shipowners and shipbuilders to have propounded to them means whereby even thirty knots per hour may be realized, and these backed up by very elaborate calculations as proof, but which, when investigated, are found, like those of a well-known writer of scientific romance, to be wanting in some little detail, insignificant at first sight, but absolutely essential to complete the proof. So far no great departure from the existing form of ship, nor from the method of propulsion, has resulted in obtaining a higher speed than is common with ordinary ships of the same dimensions; and in nearly every case such departures have mortified the inventors as well as disappointed the public by turning out absolute failures; and there