[Illustration: THE LAND-BRIDGE TO THE NEW WORLD
_A conservative map of shorelines during the last glaciation, based on a drop in sea level of 180 feet. Geologists believe that the ice impounded in the great glaciers and ice fields of the world lowered the ocean 200 to 300 feet. The southern shore of Alaska during the last glaciation may have been much nearer its present position. (After Johnston, 1933.)_]
[Illustration: A GREAT-CIRCLE ROUTE TO NORTH AMERICA
_On the flat, distorted map of Mercator, on page 4, the path of early man across Asia to the New World seems a roundabout curve. On a globe, it is very nearly a great circle. This is indicated on a map such as this, projected from a point above the North Pole. From above Bering Strait, the route would appear still straighter._]
Aleš Hrdlička has said that not many men would have frequented northeastern Siberia because of its inhospitable climate, and so only a few would have “trickled over.”[8] The opposite seems to have been true in the time of the glaciers. Then northeastern Asia was an excellent jumping-off place for the Old World migrant. In the first place, there was not much glaciation in this area, certainly nothing to interfere with the passage of people along the coast. The last glaciation was “far less extensive than its predecessor,” say R. F. Flint and H. G. Dorsey, “and was confined to the higher parts of the higher mountain ranges.”[9] Secondly, the land-bridge, which made crossing easy, also altered the climate of Siberia south of the bridge.[10] It cut off the arctic currents and therefore to some extent the arctic damp which now makes the Asiatic coast inhospitable. Hrdlička—one of the first and most violent opponents of early man in America—said that the land-bridge was not essential. Even if it had existed, “man would not have used it, but would have followed the much easier route over the water.”[11]
Once in Alaska, man—early or not so early—had a number of routes to choose from. If he was of maritime habits, and crossed by water, he would have tended to stick to his boats, and sail or paddle southward and southeastward down the coast and on through the inland passages of lower Alaska and Canada which protect boats from ocean storms. When Frank C. Hibben found a certain early kind of spear point in a curio shop in Ketchikan, Alaska, and on the far-away shore of Cook Inlet, he called attention to a route—whether overland or by sea—which hardly anyone had stressed except Hrdlička.[12] Hrdlička stressed it because he brought man over after the glaciers and in boats. But even in the Great Ice Age this route was not impossible for men without boats. Migrants who had crossed by a land-bridge might have turned south along the Pacific shore, climbing and crossing the ice barriers of the glacial rivers that still slide slowly down from the inland mountains. Philip S. Smith points out that “ice surfaces allow fully as easy travel by sled and on foot as do the ordinary land surfaces.”[13] But was there game, as well as fish, along the coast to lure the migrant on and to sustain him upon the journey?