=155. Improvement in the means and methods of navigation.=—With the extension of navigation new qualities were needed in ships; speed to cover the great distances, carrying capacity for the storage of bulky cargoes, and stability sufficient to ensure safety in tropical hurricanes or eastern typhoons. The medieval galley, rowed with oars, was, of course, unsuited to long voyages, and sails came into universal use. The favorite types of vessel all showed, however, the influence of medieval models. The caravel, of small tonnage and easily managed, was simply a galley fitted with masts and sails. The galleon was larger, having two or three decks; in it the attempt was made to unite the lines and speed of a galley with the stability and dimensions of a cargo carrier. Finally, the carrack, with four or five decks, combined great carrying capacity with the defensive strength of a floating fortress. Piracy continued to be a plague, especially in the Mediterranean and in waters outside Europe, and the large merchantman with a considerable number of guns enjoyed a great advantage over smaller vessels. We read of ships of a thousand tons and over. The size of the Hanseatic ships trading to London increased so much in the sixteenth century that they could no longer pass London Bridge, or lie at the wharf of the Steelyard; and the increase in the size of ships caused changes in the importance of ports, by which Seville gave place to Cadiz, Rouen to Havre, Dordrecht to Rotterdam. Improvements were effected also in the art of navigation, especially in the means of determining the position east and west. The simple means of the later Middle Ages could give some idea of a vessel’s latitude, but very little of its longitude. The introduction of the log in the seventeenth century enabled a sailor to measure distance traversed more accurately, and the invention of the chronometer in the eighteenth century gave at last a reliable and practical means of determining longitude at sea. Progress in scientific astronomy was made of service to sailors by tables which were the forerunners of the modern “nautical almanac”; and charts and sailing directions became, as the result of generations of experience, more trustworthy and more useful. QUESTIONS AND TOPICS 1. Character and life of Prince Henry of Portugal. [E. G. Bourne, Prince Henry the Navigator, Yale Review, Aug., 1894, 3: 187-202, reprinted in Essays in historical criticism, N. Y., 1901; or one of the readings in the bibliography.] 2. Measure on the map the distances traversed in the voyages in search of the sea-route to India; indicate these distances on a straight line, with the dates, that the rapid increase in the extent of the voyages may be apparent. 3. Early life and first voyage of Columbus. [Bourne, Spain, chaps. 1 to 3.] 4. Early Christian pilgrimages to the East. [Beazley, chap. 1.] 5. European explorers in Asia. [Cheyney, chap. 3; Verne, vol. 1, part 1; Beazley, chap. 3.]