after the Europeans realized that,
at the south, America and Asia were separated by a great sea, they
imagined that these continents were joined together at the north. The
European ideas of distance and of the form of the globe were still
confused and inexact. A party of early explorers in Virginia carried a
letter of introduction with them from the King of England to the Khan
of Tartary: they expected to find him at the head waters of the
Chickahominy. Jacques Cartier, nearly half a century after Columbus,
was expecting that the Gulf of St Lawrence would open out into a
passage leading to China. But after the discovery of the North Pacific
ocean and Bering Strait the idea that America was part of Asia, that
the natives were 'Indians' in the old sense, was seen to be absurd. It
was clear that America was, in a large sense, an island, an island cut
off from every other continent. It then became necessary to find some
explanation for the seemingly isolated position of a portion of mankind
separated from their fellows by boundless oceans.

The earlier theories were certainly naive enough. Since no known human
agency could have transported the Indians across the Atlantic or the
Pacific, their presence in America was accounted for by certain of the
old writers as a particular work of the devil. Thus Cotton Mather, the
famous Puritan clergyman of early New England, maintained in all
seriousness that the devil had inveigled the Indians to America to get
them 'beyond the tinkle of the gospel bells.' Others thought that they
were a washed-up remnant of the great flood. Roger Williams, the
founder of Rhode Island, wrote: 'From Adam and Noah that they spring,
it is granted on all hands.' Even more fantastic views were advanced.
As late as in 1828 a London clergyman wrote a book which he called 'A
View of the American Indians,' which was intended to 'show them to be
the descendants of the ten tribes of Israel.'

Even when such ideas as these were set aside, historians endeavoured to
find evidence, or at least probability, of a migration of the Indians
from the known continents across one or the other of the oceans. It
must be admitted that, even if we supposed the form and extent of the
continents to have been always the same as they are now, such a
migration would have been entirely possible. It is quite likely that
under the influence of exceptional weather--winds blowing week after
week from the same point of the compass--even