In cruising to and fro about the channel we frequently came across whales. They were usually either "finners" or "sperms"; more commonly the former. I saw only one "right" whale during the many months which we spent in these waters. On the 17th of February we steamed by a school of about twenty "finner" whales, and shortly after we passed through a shoal of small red shrimps (Galatheas), which were so densely clustered together as to give the water quite a scarlet appearance. This accounted for the great gathering of Cetaceans. Skeletons of whales in a very imperfect state were abundant about the shores of this channel, and many were of large size. On the shore of Francisco Bay I saw lower jaw bones which measured eleven feet from condyle to symphysis. I looked, but in vain, for remains of the Ziphioid Whales.
Some few miles to the eastward of Francisco Bay a deep inlet pierced Wellington Island in a northerly direction. We were anxious to explore it, as we thought it not unlikely that it might prove to be a navigable passage, connecting Trinidad Channel with the Gulf of Peñas. At length an opportunity occurred, and on a fine morning in the month of March we steamed into this unsurveyed inlet. On fairly passing the southern entrance, we found ourselves traversing a lane of water of such glassy smoothness, and bordered by such straight running shores, which were not more than half-a-mile apart, as to seem more like an inland canal than (which it eventually proved to be) a strait leading through a nest of breakers to an inhospitable ocean. Its eastern shore exhibited the kind of scenery prevailing about the Guia Narrows; viz., round-topped hills with great bare patches of rain-worn rock extending from the summits to a talus, which was covered with an uniform mantle of evergreen forest, the latter encroaching upon the sea-beach. But the country to the west presented a more pleasing variety, being composed of low undulating slopes of grassy-looking land, with here and there fissures or landslips exhibiting what seemed to us, as we scrutinized them with our glasses, to be sections of a sedimentary formation. We had hitherto seen nothing like this anywhere among the western channels, and consequently I for one was extremely anxious to land. However, the captain had to make the most of daylight for the surveying work in hand, so that our conjectures as to the nature of this formation remained unverified. When we had attained a distance of twenty-five miles from the southern entrance of the Strait, the western shore was found to be broken up into a chain of low islets, which in time dwindled away into a great arc of submerged rocks, over which the swell of the broad Pacific broke with great fury. This then was the end of what is now known as the Picton Channel, and bold would be the mariner who would attempt to traverse it, and thread his way through such a maze of reefs and breakers. Among the islets at this, its northern extremity, we found an anchorage, where we decided on stopping for the night. As we cast anchor, a native boat approached, carrying no less than twenty-three inmates, most of whom were males, and of a most savage and treacherous appearance. They had with them several young fur seals, recently killed, which they were glad to barter for tobacco or biscuit. After stopping alongside for about half-an-hour, they paddled away and were seen no more. On the following day we steamed back.
The rocky shores and islets of the Trinidad Channel bear abundant indications of old ice action. These marks are not very apparent on the coarse-grained friable syenite which is the common rock of the district, but on the dikes of hard greenstone, with which the syenite is frequently intersected, scorings and striations of typical character may be seen. Close to the anchorage in Port Charrua, on the north side of the channel, there is a broad band of greenstone on which I observed very perfect examples of "crosshatchings," where the prevailing east to west striæ were intersected by those of another system at an angle of about 40°. These rock erosions, coupled with what we know from the sounding-lead as to the contour of the sea-bottom, lead us to infer that the Trinidad Channel was at some remote period the bed of a huge glacier, which flowed westward from the Cordillera. That most, indeed, of the other straits and channels of Western Patagonia were also at one time occupied by glaciers is clearly testified by the markings on the rocks.
There is a peculiar form of syenite rock not uncommon in exposed situations on the hill-tops, which is composed of quartz, felspar, and hornblende, the quartz occurring in crystals of about the size of large peas. The felspar, being of a very friable nature, rapidly succumbs to the disintegrating influence of the weather, and crumbles away, taking with it the small particles of hornblende, so that the big quartz crystals, when in the last stage prior to being dislodged, are seen standing out in bold relief from the matrix. When this rock is seen projecting in round bosses, through the turfy soil of a hilltop, it looks at a short distance as if strewn with hailstones; and the illusion is heightened on observing on its leeward side heaps of loose quartz crystals, which have been completely weathered out from the parent rock, and have been drifted by the wind into this comparatively sheltered situation, as would be the case with hailstones under similar circumstances.
But the most characteristic feature in the scenery of the western shores of Patagonia is owing to the phenomenon of "soil motion," an occurrence which is here in a great measure due to the exceptionally wet nature of the climate. This slippage of the soilcap seems in this region to be continually taking place wherever the basement rock presents a moderately inclined surface. Some of the effects of this "soil motion" are apt to be confounded with those due to glacial action, for the soilcap takes with it in its downward progress not only its clothing of trees, ferns, and mosses, but also a "moraine profonde" of rock, stones, and stems of dead trees great and small, whereby the hills are being denuded, and the valleys, lakes, and channels gradually filled up. When we first entered the Western Channels my attention was at once directed to this subject on noticing that the lower branches of trees growing in immediate proximity to the seashore were in many places withering from immersion in the salt water, and that in some cases entire trees had perished prematurely, from their roots having become entirely submerged. On looking more closely into the matter, I noticed that sodden snags of dead trees, mingled with stones, were often to be seen on the bottom of the inshore waters, and that the beds of fresh-water lakes were plentifully strewn with similar fragments of wood, the remains of bygone forests which had perished prematurely. These circumstances are fully explained by the occurrence of soil motion, for as the soilcap by its sliding motion, imparted by gravitation, and aided by expansion and contraction of the spongy mass, reaches the water's edge, the soluble portions are removed, while its more durable contents are left to accumulate at the foot of the incline. In this way rocks and stones may sometimes be seen balanced in odd situations near the sea beach, simulating the "roches perchées" which are dropped by a melting iceberg or a receding glacier. These circumstances are all the more interesting from their occurring in a region where the effects of old and recent glacial action are exhibited to a marked degree. Planings, scorings, striations, and "roches moutonnées" may, one or other, be almost invariably found wherever the rock is sufficiently impervious to the disintegrating action of the weather to retain these impressions. Thus they are nowhere to be seen on the coarse-grained friable syenite, which is the common rock of the district; but where this rock is intersected by dikes of the more durable greenstone, the above-mentioned signs of former glacial action may be seen well developed. I speak now of old glacial action, because we have not found any glacier existing in the neighbourhood of the Trinidad Channel, from whence they seem to have entirely receded; but they are yet to be seen in the fiords of the mainland further north; and in the main Straits of Magellan we had opportunities of studying fine examples of complete and incomplete glaciers, exhibiting in all its grandeur that wonderful denuding power which these ponderous masses of ice exercise as they move silently over their rocky beds. There are, therefore, in this region, ample opportunities of comparing and differentiating phenomena, which have resulted from former glacial action, and those which are due to soil motion—a force now in operation.
Sir Wyville Thompson (vide "Voyage of Challenger," vol. ii., p. 245) attributes the origin of the celebrated "Stone Runs" of the Falkland Islands to the transporting action of the soilcap, which among other causes derives its motion from alternate expansion and contraction of the spongy mass of peat, due to varying conditions of moisture and comparative dryness; and this hypothesis is to a certain extent supported by the occurrences which I now endeavour to describe. Here, in Western Patagonia, an evergreen arboreal forest, rising through a dense undergrowth of brushwood and mosses, clothes the hillsides to a height of about 1,000 feet, and this mass of vegetation, with its subjacent peaty, swampy soil, resting—as it frequently does—upon a hillside already planed by old ice action, naturally tends, under the influence of gravitation, combined with that of expansion and contraction of the soil, to slide gradually downwards until it meets the sea, lake, or valley, as the case may be. In the two former cases the free edge of the mass is removed by the action of the water, in a manner somewhat analogous to the wasting of the submerged snout of a "complete glacier" in the summer time; whereas in the last instance a chaotic accumulation of all the constituents of the transported mass gradually takes place, thereby tending to an eventual obliteration of the valley. It appears to me that the conditions which are said to have resulted in the formation of the "Stone Runs" of the Falklands here exist in equal if not greater force. There is a thick spongy vegetable mass covering the hillsides, and acted on by varying conditions of extreme moisture and comparative dryness; there are the loose blocks of disintegrating syenite to be transported; and there are mountain torrents, lakes, and sea-channels to remove the soil. That motion of the soilcap does actually take place we have at least strong presumptive evidence; but anything resembling a "stone run" remains yet to be discovered. It would naturally suggest itself to the reader that the above phenomenon attributed to soil motion might be accounted for by a slow and gradual depression of the land, and I have carefully sought for evidence favouring this view, but have found no reliable sign whatever of subsidence; while on the other hand one sees raised beaches and stones testifying to the ravages of stone-boring molluscs at heights above the present high-water marks, which indicate that even elevation of the land has taken place.
On May 6th, the winter season having then fairly set in, we bade adieu for a while to our surveying ground, and commenced our northern voyage to Valparaiso. Our course lay first through the sheltered channels which separate Wellington Island from the mainland. As we rounded Topar Island and entered Wide Channel, the heavy mist which had been hanging around us all the morning, almost concealing the land from sight, lifted at intervals like a veil, and exposed to view the noble cliffs of bare greenstone rock which hemmed us in on either side,—here and there streaked down their faces by long slender cascades of water, extending from summit to base, and seeming to hang over us like glistening threads of silver. On passing the southern outlet of Icy Reach, we saw shining in the distance the sloping tongue-shaped extremity of one of the Eyre Sound glaciers, whose bergs float out through Icy Reach in the winter time and sometimes prove a serious obstruction to navigation in these gloomy and mysterious channels. In Chasm Reach, which we next traversed, the hills on either side rose nearly perpendicularly to a height of 1,500 feet, their snow-capped summits contrasting grandly with the sombre tints of their rocky sides; so scantily clad with vegetation as to seem at a distance mere sloping walls of rock.
In the narrowest part of this "reach," where the width was only about half-a-mile, three native huts were seen established on low projecting shelves of rock, and situated about a mile apart. To these our attention was attracted by the long curling wreaths of grey smoke ascending from their fires. As darkness was coming on, we did not stop to examine them, but steamed on towards Port Grappler, where we anchored for the night.
We got under way early in the morning of the following day, and proceeded through the channel as far as Hoskyn Cove, an anchorage just to the northward of the famous English Narrows. The morning had been hazy and showery, but towards noon the mist cleared away, and as we passed the English Narrows, a burst of sunshine completed the dispersion of the hazy vapour and lighted up a scene of surpassing splendour. The scenery here contrasted strangely with that of Chasm Reach, for the steep hillsides now were richly clothed with a luxuriant growth of primeval forest, and rising to a greater altitude, had their summits capped with a broad mantle of snow, which showed to great advantage against the deep blue of the sky. In the narrowest part of the channel, where the flood tide was making southward in a rapid stream, numbers of fur seals were gambolling in the water, and the energetic movements of the cormorants testified to the abundance of the fish.