Alexander Mackenzie, the hero of these important trips, was bred a clerk in the service of the North-west Company, and, before starting on his voyage as a geographical explorer, properly so called, had served a long apprenticeship at the advanced station of Fort Chipewyan, on the Athapescow Lake, whence he made several overland excursions in different directions. On the 3d June, 1789, our hero embarked in a native canoe on the Slave River, and following its course, then unimpeded by ice, in a northerly direction, he arrived on the 9th of the same month at the Slave Lake. Skirting along its shores in a westerly direction, he presently discovered the important river bearing his name, which has since been found to be identical with the Athabasca, rising in the Rocky Mountains near Mount Brown, and also with the Slave, the combined waters of the two streams flowing, after their junction, to the Arctic Ocean in Mackenzie Bay, N. lat. 70°, W. long. 136°. Anxious to trace the course of the Mackenzie, the explorer was about to proceed along it in his canoe, when he was told by some wandering Indians that certain death would be the result, for the bed of the stream was haunted by huge monsters, who would devour all who came in their way. Moreover, it would take many years to reach the salt water. The white man had better return the way he came. In any case, he could hope for no help from the redskins. Though these terrible prophecies did not affect Mackenzie himself, they paralyzed his guides, who declared they would go no further; and after trying alike persuasion and force, the Europeans determined to do the best they could alone. They appear to have penetrated as far north as the Great Bear Lake, but here, for some reason of which we find no explanation in Mackenzie’s journal, the canoe was turned southward, and the voyage back to the Slave Lake resumed. “My people,” says Mackenzie, “could not refrain from some expressions of real concern that they were obliged to return without reaching the sea;” but he apparently made no great effort to gratify them. Back again to Fort Chipewyan, Mackenzie lost no time in preparing for a second journey of discovery. Embarking on the Peace River, a tributary of the Slave or Athabasca, he followed its course in a south-westerly direction, till he reached the first spurs of the snow-clad Rocky Mountains, whence issued the river under examination. Here the canoe was, of necessity, abandoned, and an arduous climb began, resulting, however, in the successful scaling of the rugged ridge, and the safe arrival at a village on its western side, where the weary travelers were regaled with salmon, a fish never before met with on their travels in North America. Illustration: MACKENZIE’S FIRST VIEW OF THE PACIFIC OCEAN.