For the moment this is the last important safety device that has been invented to help lessen the perils of sea voyages. Indeed the perils and discomforts of ocean voyages are now largely reminiscent, thanks to the rapid succession of scientific discoveries and their practical application during the last half century. The size of modern vessels minimizes rolling and pitching. Turbine engines practically eliminate engine vibrations. The danger from fires was practically eliminated by the introduction of iron and steel as building material; the danger of sinking after collisions is now guarded against by the division of the ship's hull into water-tight compartments; sensitive instruments as used at present warn the mariner of the presence of ice-bergs; wireless telegraphy affords a means of calling aid in case of disabled machinery and giving the ship's location in a general way; while the submarine signal makes known the exact location of the stricken vessel in foggy weather. In a trifle over half a century the time of crossing the Atlantic has been reduced by more than one-half. In 1856 the _Persia_ crossed the ocean between Queenstown and New York in nine days, one hour, and forty-five minutes, making a new record. In 1909 the _Mauretania_ covered the same distance in four days, ten hours, and fifty-one minutes. In March, 1910, the same vessel completed a passage over the longer winter course, a distance of 2,889 knots, in four days, fifteen hours, and twenty-nine minutes, reducing the previous record by twenty-nine minutes. When the _Lusitania_ and _Mauretania_ were completed many short-sighted persons predicted that these vessels would never be surpassed in size or speed. As if to refute such predictions, however, the White Star Company at once began constructing two vessels, the _Olympic_ and _Titanic_, each with a displacement of one-fourth more than the great Cunarders, and of overshadowing proportions in everything save the matter of speed. Against the _Mauretania's_ average twenty-six knot speed the new boats are designed to make only twenty-one. These new boats are eight hundred and ninety feet in length, as against the _Lusitania's_ seven hundred and ninety. They are ninety-two feet in beam, and sixty-two feet in molded depth. The roof of the pilot house is seventy feet above the water. The maximum draft is thirty-seven and a half feet and the displacement sixty thousand tons. They resemble the _Great Eastern_ in that they have two systems of engines. Two reciprocating engines drive the two outer of the three screws, and the exhaust from these engines is utilized in a low-pressure turbine engine, driving the center propeller. LIQUID FUEL