In two other aspects the sea exerted marked influence upon both the discovery and the settlement of the new lands, as well as upon their later history. The fact that America and Europe are separated by three thousand miles of water must be considered in relation to culture at various periods; for geographic factors are relative, and not absolute, in their historic connotations. Countries may be said to be habitable or uninhabitable, distances to lengthen or shorten, heights to rise or fall, according to the measure of man's control over nature at any given time. As a distinguished French geographer has said: “Tout se transforme autour de nous; tout diminue ou s'accroît. Rien n'est vraiment immobile et invariable.”[17] Increase in speed of vessels, with increased storage capacity for food and water, is equivalent to an actual reduction of the distance in miles; and, measured by the standards of modern ships in speed alone, without considering other factors, we may say that twenty to thirty thousand miles of uncharted seas had kept America hidden from European eyes. Footnote 17: Jean Brunhes, _La géographie humaine_ (Paris, 1912), p. 6. Across this wide expanse, in the latitude of Europe, the currents of both air and water set from America toward the Old World, and almost precluded the possibility, under primitive conditions, of European voyaging and discovery. North of this eastward track, however, lie not only the stepping-stones of the Faroe Islands, Iceland, and Greenland, but, once at Iceland, the prevailing wind carries the European mariner to Greenland, whence the Labrador current leads him close inshore and along the coasts of Canada and New England.[18] To the south of the central eastward track, is the zone of the trade-winds and the great westward flowing equatorial current; and there, again, we find island stepping-stones. Thus nature clearly indicated the two ways by which America might be found; and, for long, the routes followed were the northerly one to the Newfoundland fisheries and New England, and the southerly one to the Canaries, the West Indies, and, thence, to Virginia. The earliest English efforts at colonization in North America were at the two points lying nearest to England by wind and ocean current. Footnote 18: In the Middle Ages there was apparently an additional volcanic island, known as Gunnbiörn's Skerries, between Iceland and Greenland, destroyed by eruption in 1456. R. H. Major, _Voyages of the Zeni_ (Hakluyt Society, 1873), pp. lxxiv _ff._