During the course of the fifteenth century, the geographical limits that had contained the European economy for centuries were finally and irreparably shattered, and, as a result, there arose what one recent historian has chosen to call the “European world-economy.” The change was not simply a new awareness of the broader dimensions of the earth; medieval men had already colonized Iceland, touched America, traveled to China, and made some progress in the economic exploitation of the Atlantic islands, especially the Canaries. It was rather a new permanence, a regularization of contacts, and the development of a technology capable of sustaining wider geographical and economic probes. Ship design improved rapidly; building on ideas long available but ultimately original in combination, shipwrights produced vessels capable of withstanding the vagaries of the Atlantic weather patterns and of covering the vast distances between continents. The initial challenge of substituting sails for manpower and oars had been overcome in the fourteenth century, and marine technology developed further during the fifteenth, when the single-masted, square-rigged ship was brought to a high degree of sophistication. Crew size contracted sharply while cargo space rose concomitantly; geographical range was enhanced by the increased capacity to carry food supplies for smaller crews at the same time as the economic potential of such vessels rose with the expansion of available cargo space. By the late fifteenth century, additional improvements in rigging and hull design had been mastered. Ships grew longer in relation to their beams, and longer, thinner ships proved more suitable for ocean sailing.