where strong tidal currents carry the sea far
into these channels of the land. The tides move up the St. Lawrence
River 430 miles (700 kilometers) or half way between Montreal and
Quebec, and up the Amazon 600 miles (1,000 kilometers). Owing to their
resemblance to pelagic channels, the estuaries of the American rivers
with their salty tide were repeatedly mistaken, in the period of
discoveries, for the Northwest Passage to the Pacific. Newport in 1608
explored the broad sluggish course of the James River in his search for
a western ocean. Henry Hudson ascended the Hudson River almost as far as
Albany, before he discovered that this was no maritime pathway, like the
Bosporus or Dardanelles, leading to an ulterior sea. The long tidal
course of the St. Lawrence westward into the heart of the continent fed
La Salle's dream of finding here a water route to the Pacific, and fixed
his village of "La Chine" above the rapids at Montreal as a signpost
pointing the way to the Indies and Cathay. In the same way a tidal river
at the head of Cook's Inlet on the Alaskan coast was mistaken for a
Northeast Passage, not by Captain Cook but by his fellow officers, on
his Pacific voyage of 1776-1780; and it was followed for several days
before its character as a river was established.[632]

[Sidenote: Sea navigation merges into river navigation.]

Rivers have always been the great intermediaries between land and sea,
for in the ocean all find their common destination. Until the
construction of giant steamers in recent years, sea navigation has
always passed without break into river navigation. Sailing vessels are
carried by the trade wind 600 miles up the Orinoco to San Fernando.
Alexander's discovery of the Indus River led by almost inevitable
sequence to the rediscovery of the Eastern sea route, which in turn ran
from India through the Strait of Oman and the Persian Gulf up the
navigable course of the Euphrates to the elbow of the river at
Thapsacus. Enterprising sea folk have always used rivers as natural
continuations of the marine highway into the land. The Humber estuary
and its radiating group of streams led the invading Angles in the sixth
century into the heart of Britain.[633] The long navigable courses of the
rivers of France exposed that whole country to the depredations of the
piratical Northmen in the ninth and tenth centuries. Up every river they
came, up the Scheldt into Flanders, the Seine to Paris and the Marne to
Meau