Engineering Wonders of the World
Volume I

358 ENGINEERING WONDERS OF THE WORLD. Fig. 13.—MAKING A TEST. The men on the Carriage are watching, by means of instruments, the behaviour of the Model in the tank below. sea-sickness, and in warships also a minimum rolling motion is essential to secure a steady gun platform. The most important factors in providing steadiness are a comparatively small metacentric height and distribution of the heavier weights far from the axis about which the ship rolls. Fortunately, this con- dition of affairs exists in the case of most large passenger vessels, and Atlantic liners, having metacentric heights of from 15 to 18 inches, have proved remarkable for their steadiness. Owing to the extra draught of water required for a centre keel, it is now the usual practice to fit keels at the bilge instead of a centre keel, and experience has shown the efficiency of these bilge keels, especially in vessels having a very round bilge. A new method of preventing rolling has re- cently been devised in the Schlick gyroscope, which has been tried with great success on board an experimental vessel, and on the pas- senger steamers Silvana and Lochiel, the latter one of Messrs. MacBrayne’s vessels plying on the west coast of Scotland ; and its application appears to offer great possibilities for the smaller classes of passenger vessels and war- ships. Such are, briefly, some of the main factors the naval architect has to consider in design- ing a new ship ; and, needless to point out, they could be greatly enlarged upon if space permitted. Enough has been said, however, to show that the designing of a ship is one of the most comprehensive and difficult prob- lems in the field of applied science.