Louis Agassiz: His Life and Correspondence

by Louis Agassiz

LOUIS AGASSIZ TO SIR PHILIP EGERTON.

NEUCHATEL, September 10, 1839.

. . .Under these circumstances, I thought I could not do better than to pass some weeks in the solitude of the high Alps; I lived about a fortnight in the region of the glaciers, ascending some new field of ice every day, and trying to scale the sides of our highest peaks. I thus examined in succession all the glaciers descending from the majestic summits of Monte Rosa and the Matterhorn, whose numerous crests form a most gigantic amphitheatre, which lifts itself above the everlasting snow. Afterward I visited the sea of ice which, under the name of the glacier of Aletsch, flows from the Jungfrau, the Monch, and the Eiger toward Brieg; thence I went to the glacier of the Rhone, and from there, establishing my headquarters at the Hospice of the Grimsel, I followed the glacier of the Aar to the foot of the Finsteraarhorn. There I ascertained the most important fact that I now know concerning the advance of glaciers, namely, that the cabin constructed by Hugi in 1827, at the foot of the Abschwung, is now four thousand feet lower down. Slight as is the inclination of the glacier, this cabin has been carried on by the ice with astonishing rapidity, and still more important is it that this rapidity has been on the increase; for in 1830 the cabin was only some hundred feet from the rock, in 1836 it had already passed over a distance from [word torn away] of two thousand feet, and in the last three years it has again doubled that distance. Not only have I confirmed my views upon glaciers and their attendant phenomena, on this new ground, but I have completed my examination of a number of details, and have had besides the satisfaction of convincing one of my most severe opponents of the exactness of my observations, namely, M. Studer, who accompanied me on a part of these excursions. . .

The winter of 1840 was fully occupied by the preparation for the publication of the "Etudes sur les Glaciers," which appeared before the year was out, accompanied by an atlas of thirty-two plates. The volume of text consisted of an historical resume of all that had previously been done in the study of glaciers, followed by an account of the observations of Agassiz and his companions during the last three or four years upon the glaciers of the Alps. Their structure, external aspect, needles, tables, perched blocks, gravel cones, rifts, and crevasses, as well as their movements, mode of formation, and internal temperature, were treated in succession. But the most interesting chapters, from the author's own point of view, and those which were most novel for his readers, were the concluding ones upon the ancient extension of the Swiss glaciers, and upon the former existence of an immense, unbroken sheet of ice, which had once covered the whole northern hemisphere. No one before had drawn such vast conclusions from the local phenomena of the Alpine valleys. "The surface of Europe," says Agassiz, "adorned before by a tropical vegetation and inhabited by troops of large elephants, enormous hippopotami, and gigantic carnivora, was suddenly buried under a vast mantle of ice, covering alike plains, lakes, seas and plateaus. Upon the life and movement of a powerful creation fell the silence of death. Springs paused, rivers ceased to flow, the rays of the sun, rising upon this frozen shore (if, indeed, it was reached by them), were met only by the breath of the winter from the north and the thunders of the crevasses as they opened across the surface of this icy sea."* (* "Etudes sur les Glaciers" Chapter 8 page 35.) The author goes on to state that on the breaking up of this universal shroud the ice must have lingered longest in mountainous strongholds, and that all these fastnesses of retreat became, as the Alps are now, centres of distribution for the broken debris and rocky fragments which are found scattered with a kind of regularity along certain lines, and over given areas in northern and central Europe. How he followed out this idea in his subsequent investigations will be seen hereafter.

CHAPTER 10.

1840-1842: AGE 33-35.

Summer Station on the Glacier of the Aar.
Hotel des Neuchatelois.
Members of the Party.
Work on the Glacier.
Ascent of the Strahleck and the Siedelhorn.
Visit to England.
Search for Glacial Remains in Great Britain.
Roads of Glen Roy.
Views of English Naturalists concerning Agassiz's Glacial Theory.
Letter from Humboldt.
Winter Visit to Glacier.
Summer of 1841 on the Glacier.
Descent into the Glacier.
Ascent of the Jungfrau.

In the summer of 1840 Agassiz made his first permanent station on the Alps. Hitherto the external phenomena, the relation of the ice to its surroundings, and its influence upon them, had been the chief study. Now the glacier itself was to be the main subject of investigation, and he took with him a variety of instruments for testing temperatures: barometers, thermometers, hygrometers, and psychometers; beside a boring apparatus, by means of which self-registering thermometers might be lowered into the heart of the glacier. To these were added microscopes for the study of such insects and plants as might be found in these ice-bound regions. The Hospice of the Grimsel was selected as his base of supplies, and as guides Jacob Leuthold and Johann Wahren were chosen. Both of these had accompanied Hugi in his ascension of the Finsteraarhorn in 1828, and both were therefore thoroughly familiar with all the dangers of Alpine climbing. The lower Aar glacier was to be the scene of their continuous work, and the centre from which their ascents of the neighboring summits would be made. Here, on the great median moraine, stood a huge boulder of micaceous schist. Its upper surface projected so as to form a roof, and by closing it in on one side with a stone wall, leveling the floor by a judicious arrangement of flat slabs, and rigging a blanket in front to serve as a curtain across the entrance, the whole was presently transformed into a rude hut, where six persons could find sleeping-room. A recess, sheltered by the rock outside, served as kitchen and dining-room; while an empty space under another large boulder was utilized as a cellar for the keeping of provisions. This was the abode so well known afterward as the Hotel des Neuchatelois. Its first occupants were Louis Agassiz, Edouard Desor, Charles Vogt, Francois de Pourtales, Celestin Nicolet, and Henri Coulon. It afforded, perhaps, as good a shelter as they could have found in the old cabin of Hugi, where they had hoped to make their temporary home. In this they were disappointed, for the cabin had crumbled on its last glacial journey. The wreck was lying two hundred feet below the spot where they had seen the walls still standing the year before.

The work was at once distributed among the different members of the party,—Agassiz himself, assisted by his young friend and favorite pupil, Francois de Pourtales, retaining for his own share the meteorological observations, and especially those upon the internal temperature of the glaciers.* (* See "Tables of Temperature, Measurements" etc., in Agassiz's "Systeme Glaciaire". These results are also recorded in a volume entitled "Sejours dans les Glaciers", by Edouard Desor, a collection of very bright and entertaining articles upon the excursions and sojourns made in the Alps, during successive summers, by Agassiz and his scientific staff.) To M. Vogt fell the microscopic study of the red snow and the organic life contained in it; to M. Nicolet, the flora of the glaciers and the surrounding rocks; to M. Desor, the glacial phenomena proper, including those of the moraines. He had the companionship and assistance of M. Henri Coulon in the long and laborious excursions required for this part of the work.

This is not the place for scientific details. For the results of Agassiz's researches on the Alpine glaciers, to which he devoted much of his time and energy during ten years, from 1836 to 1846, the reader is referred to his two larger works on this subject, the "Etudes sur les Glaciers," and the "Systeme Glaciaire." Of the work accomplished by him and his companions during these years this slight summary is given by his friend Guyot.* (* See Biographical Sketch, published by Professor A. Guyot, under the auspices of the United States National Academy.) "The position of eighteen of the most prominent rocks on the glacier was determined by careful triangulation by a skillful engineer, and measured year after year to establish the rate of motion of every part. The differences in the rate of motion in the upper and lower part of the glacier, as well as in different seasons of the year, was ascertained; the amount of the annual melting was computed, and all the phenomena connected with it studied. All the surrounding peaks,—the Jungfrau, the Schreckhorn, the Finsteraarhorn, most of them until then reputed unscalable,—were ascended, and the limit of glacial action discovered; in short all the physical laws of the glacier were brought to light."