Louis Agassiz: His Life and Correspondence

by Louis Agassiz

We now return to the personal narrative. After a number of days spent in the study of the local phenomena, the band of workers turned their attention to the second part of their programme, namely, the ascent of the Strahleck, by crossing which and descending on the other side, they intended to reach Grindelwald. One morning, then, toward the end of August, their guides, according to agreement, aroused them at three o'clock,—an hour earlier than their usual roll-call. The first glance outside spread a general chill of disappointment over the party, for they found themselves beleaguered by a wall of fog on every side. But Leuthold, as he lighted the fire and prepared breakfast, bade them not despair,—the sun might make all right. In a few moments, one by one, the summits of the Schreckhorn, the Finsteraarhorn, the Oberaarhorn, the Altmaner, the Scheuchzerhorn, lighted by the first rays of the sun, came out like islands above the ocean of mist, which softly broke away and vanished with the advancing light. In about three hours they reached the base of the Strahleck. Their two guides, Leuthold and Wahren, had engaged three additional men for this excursion, so that they now had five guides, none of whom were superfluous, since they carried with them various barometric instruments which required careful handling. They began the ascent in single file, but the slopes soon became so steep and the light snow (in which they floundered to the knees at every step) so deep, that the guides resorted to the usual method in such cases of tying them all together. The two head guides alone, Leuthold and Wahren, remained detached, clearing the snow in front of them, cutting steps in the ice, and giving warning, by cry and gesture, of any hidden danger in the path. At nine o'clock, after an hour's climbing, they stepped upon the small plateau, evenly covered with unbroken snow, formed by the summit of the Strahleck.

The day had proved magnificent. With a clear sky above them, they looked down upon the valley of Grindelwald at their feet, while around and below them gathered the Scheideck and the Faulhorn, the pyramidal outline of the Niesen, and the chain of the Stockhorn. In front lay the great masses of the Eiger and the Monch, while to the southwest the Jungfrau rose above the long chain of the Viescherhorner. The first pause of silent wonder and delight, while they released themselves from their cords and arranged their instruments, seems to have been succeeded by an outburst of spirits; for in the journal of the youngest of the party, Francois de Pourtales, then a lad of seventeen, we read: "The guides began to wrestle and we to dance, when suddenly we saw a female chamois, followed by her young, ascending a neighboring slope, and presently four or five more stretched their necks over a rock, as if to see what was going on. Breathless the wrestlers and the dancers paused, fearing to disturb by the slightest movement creatures so shy of human approach. They drew nearer until within easy gunshot distance, and then galloping along the opposite ridge disappeared over the summit."

The party passed more than an hour on the top of the Strahleck, making observations and taking measurements. Then having rested and broken their fast with such provisions as they had brought, they prepared for a descent, which proved the more rapid, since much of it was a long slide. Tied together once more, they slid, wherever they found it possible to exchange the painful and difficult walking for this simpler process. "Once below these slopes of snow," says the journal of young de Pourtales again, "rocks almost vertical, or narrow ledges covered with grass, served us as a road and brought us to the glacier of the Grindelwald. To reach the glacier itself we traversed a crevasse of great depth, and some twenty feet wide; on a bridge of ice, one or two feet in width, and broken toward the end, where we were obliged to spring across. Once on the glacier the rest was nothing. The race was to the fastest, and we were soon on the path of the tourists." Reaching the village of Grindelwald at three o'clock in the afternoon, they found it difficult to persuade the people at the inn that they had left the glacier of the Aar that morning. From Grindelwald they returned by the Scheideck to the Grimsel, visiting on their way the upper glacier of Grindelwald, the glacier of Schwartzwald, and that of Rosenlaui, in order to see how far these had advanced since their last visit to them. After a short rest at the Hospice of the Grimsel, Agassiz returned with two or three of his companions to their hut on the Aar glacier for the purpose of driving stakes into the holes previously bored in the ice. He hoped by means of these stakes to learn the following year what had been the rate of movement of the glacier. The summer's work closed with the ascent of the Siedelhorn. In all these ascents, the utmost pains was taken to ascertain how far the action of the ice might be traced upon these mountain peaks and the limits determined at which the polished surfaces ceased, giving place to the rough, angular rock which had never been modeled by the ice.

Agassiz had hardly returned from the Alps when he started for England. He had long believed that the Highlands of Scotland, the hilly Lake Country of England, and the mountains of Wales and Ireland, would present the same phenomena as the valleys of the Alps. Dr. Buckland had offered to be his guide in this search after glacier tracks, as he had formerly been in the hunt after fossil fishes in Great Britain. When, therefore, the meeting of the British Association at Glasgow, at which they were both present, was over, they started together for the Highlands. In a lecture delivered by Agassiz, at his summer school at Penikese, a few months before his death, he recurred to this journey with the enthusiasm of a young man. Recalling the scientific isolation in which he then stood, opposed as he was to all the prominent geologists of the day, he said: "Among the older naturalists, only one stood by me. Dr. Buckland, Dean of Westminster, who had come to Switzerland at my urgent request for the express purpose of seeing my evidence, and who had been fully convinced of the ancient extension of ice there, consented to accompany me on my glacier hunt in Great Britain. We went first to the Highlands of Scotland, and it is one of the delightful recollections of my life that as we approached the castle of the Duke of Argyll, standing in a valley not unlike some of the Swiss valleys, I said to Buckland: 'Here we shall find our first traces of glaciers;' and, as the stage entered the valley, we actually drove over an ancient terminal moraine, which spanned the opening of the valley." In short, Agassiz found, as he had anticipated, that in the mountains of Scotland, Wales, and the north of England, the valleys were in many instances traversed by terminal moraines and bordered by lateral ones, as in Switzerland. Nor were any of the accompanying phenomena wanting. The characteristic traces left by the ice, as well known to him now as the track of the game to the hunter; the peculiar lines, furrows, and grooves; the polished surfaces, the roches moutonnees; the rocks, whether hard or soft, cut to one level, as by a rigid instrument; the unstratified drift and the distribution of loose material in relation to the ancient glacier beds,—all agreed with what he already knew of glacial action. He visited the famous "roads of Glen Roy" in the Grampian Hills, where so many geologists had broken a lance in defense of their theories of subsidence and upheaval, of ancient ocean-levels and sea-beaches, formed at a time when they believed Glen Roy and the adjoining valleys to have been so many fiords and estuaries. To Agassiz, these parallel terraces explained themselves as the shores of a glacial lake, held back in its bed for a time by neighboring glaciers descending from more sheltered valleys. The terraces marked the successively lower levels at which the water stood, as these barriers yielded, and allowed its gradual escape.* (* For details, see a paper by Agassiz on "The Glacial Theory and its Recent Progress" in the "Edinburgh New Philosophical Journal" October 1842, accompanied by a map of the Glen Roy region, and also an article entitled "Parallel Roads of Glen Roy, in Scotland," in the second volume of Agassiz's "Geological Sketches".) The glacial action in the whole neighborhood was such as to leave no doubt in the mind of Agassiz that Glen Roy and the adjoining glens, or valleys, had been the drainage-bed for the many glaciers formerly occupying the western ranges of the Grampian Hills. He returned from his tour satisfied that the mountainous districts of Great Britain had all been centres of glacial distribution, and that the drift material and the erratic boulders, scattered over the whole country, were due to exactly the same causes as the like phenomena in Switzerland. On the 4th of November, 1840, he read a paper before the Geological Society of London, giving a summary of the scientific results of their excursion, followed by one from Dr. Buckland, who had become an ardent convert to his views. Apropos of this meeting, Dr. Buckland writes in advance as follows:—

TAYMOUTH CASTLE, October 15, 1840.

. . .Lyell has adopted your theory in toto!!! On my showing him a beautiful cluster of moraines, within two miles of his father's house, he instantly accepted it, as solving a host of difficulties that have all his life embarrassed him. And not these only, but similar moraines and detritus of moraines, that cover half of the adjoining counties are explicable on your theory, and he has consented to my proposal that he should immediately lay them all down on a map of the county and describe them in a paper to be read the day after yours at the Geological Society. I propose to give in my adhesion by reading, the same day with yours, as a sequel to your paper, a list of localities where I have observed similar glacial detritus in Scotland, since I left you, and in various parts of England.

There are great reefs of gravel in the limestone valleys of the central bog district of Ireland. They have a distinct name, which I forget. No doubt they are moraines; if you have not, ere you get this, seen one of them, pray do so.* (* Agassiz was then staying at Florence Court, the seat of the Earl of Enniskillen, in County Fermanagh, Ireland. While there he had an opportunity of studying most interesting glacial phenomena. ) But it will not be worth while to go out of your way to see more than one; all the rest must follow as a corollary. I trust you will not fail to be at Edinboro' on the 20th, and at Sir W. Trevelyan's on the 24th. . .

A letter of later date in the same month shows that Agassiz felt his views to be slowly gaining ground among his English friends.

LOUIS AGASSIZ TO SIR PHILIP EGERTON.

LONDON, November 24, 1840.