The current was now very swift, and we were obliged to cordelle the boat along the left shore, where the bank was covered with large masses of rocks. Night overtook us at the upper end of the island, a short distance below the cascades, and we halted on the open point. In the mean time, the lighter canoes, paddled altogether by Indians, had passed ahead, and were out of sight. With them was the lodge, which was the only shelter we had, with most of the bedding and provisions. We shouted, and fired guns; but all to no purpose, as it was impossible for them to hear above the roar of the river; and we remained all night without shelter, the rain pouring down all the time. The old voyageurs did not appear to mind it much, but covered themselves up as well as they could, and lay down on the sand- beach, where they remained quiet until morning. The rest of us spent a rather miserable night; and, to add to our discomfort, the incessant rain extinguished our fires; and we were glad when at last daylight appeared, and we again embarked.

Crossing to the right bank, we cordelled the boat along the shore, there being no longer any use of the paddles, and put into a little bay below the upper rapids. Here we found a lodge pitched, and about 20 Indians sitting around a blazing fire within, making a luxurious breakfast with salmon, bread, butter, sugar, coffee, and other provisions. In the forest, on the edge of the high bluff overlooking the river, is an Indian graveyard, consisting of a collection of tombs, in each of which were the scattered bones of many skeletons. The tombs were made of boards, which were ornamented with many figures of men and animals of the natural size-- from their appearance, constituting the armorial device by which, among Indians, the chiefs are usually known.

The masses of rock displayed along the shores of the ravine in the neighborhood of the cascades, are clearly volcanic products. Between this cove, which I called Graveyard bay, and another spot of smooth water above, on the right, called Luders bay, sheltered by a jutting point of huge rocky masses at the foot of the cascades, the shore along the intervening rapids is lined with precipices of distinct strata of red and variously-colored lavas, in inclined positions.

The masses of rock forming the point at Luders bay consist of a porous trap, or basalt--a volcanic product of a modern period. The rocks belong to agglomerated masses, which form the immediate ground of the cascades, and have been already mentioned as constituting a bed of cemented conglomerate rocks, appearing at various places along the river. Here they are scattered along the shores, and through the bed of the river, wearing the character of convulsion, which forms the impressive and prominent feature of the river at this place.

Wherever we came in contact with the rocks of these mountains, we found them volcanic, which is probably the character of the range; and at this time, two of the great snowy cones, Mount Regnier and St. Helens, were in action. On the 23d of the preceding November, St. Helens had scattered its ashes, like a white fall of snow, over the Dalles of the Columbia, 50 miles distant. A specimen of these ashes was given to me by Mr. Brewer, one of the clergymen at the Dalles.

The lofty range of the Cascade mountains forms a distinct boundary between the opposite climates of the regions along its western and eastern bases. On the west, they present a barrier to the clouds of fog and rain which roll up from the Pacific ocean and beat against their rugged sides, forming the rainy season of the winter in the country along the coast. Into the brighter skies of the region along their eastern base, this rainy winter never penetrates; and at the Dalles of the Columbia the rainy season is unknown, the brief winter being limited to a period of about two months, during which the earth is covered with the slight snows of a climate remarkably mild for so high a latitude. The Cascade range has an average distance of about 130 miles from the sea-coast. It extends far both north and south of the Columbia, and is indicated to the distant observer, both in course and position, by the lofty volcanic peaks which rise out of it, and which are visible to an immense distance.

During several days of constant rain, it kept our whole force laboriously employed in getting our barge and canoes to the upper end of the Cascades. The portage ground was occupied by emigrant families; their thin and insufficient clothing, bareheaded and barefooted children, attesting the length of their journey, and showing that they had, in many instances, set out without a due preparation of what was indispensable.

A gentleman named Luders, a botanist from the city of Hamburg, arrived at the bay I have called by his name while we were occupied in bringing up the boats. I was delighted to meet at such a place a man of kindred pursuits; but we had only the pleasure of a brief conversation, as his canoe, under the guidance of two Indians, was about to run the rapids; and I could not enjoy the satisfaction of regaling him with a breakfast, which, after his recent journey, would have been an extraordinary luxury. All of his few instruments and baggage were in the canoe, and he hurried around by land to meet it at the Graveyard bay; but he was scarcely out of sight, when, by the carelessness of the Indians, the boat was drawn into the midst of the rapids, and glanced down the river, bottom up, with a loss of every thing it contained. In the natural concern I felt for his misfortune, I gave to the little cove the name of Luders bay.

15th.--We continued to-day our work at the portage.

About noon, the two barges of the express from Montreal arrived at the upper portage landing, which, for large boats, is on the right bank of the river. They were a fine-looking crew, and among them I remarked a fresh- looking woman and her daughter, emigrants from Canada. It was satisfactory to see the order and speed with which these experienced water-men effected the portage, and passed their boats over the cascades. They had arrived at noon, and in the evening they expected to reach Vancouver. These bateaux carry the express of the Hudson Bay Company to the highest navigable point of the North Fork of the Columbia, whence it is carried by an overland party to Lake Winipec, where it is divided; part going to Montreal, and part to Hudson Bay. Thus a regular communication is kept up between three very remote points.