Louis Agassiz: His Life and Correspondence Part 13

More tempting still must have been the official invitation received a few months later to a professors.h.i.+p at Lausanne, strengthened as it was by the affectionate entreaties of relations and friends, urging him for the sake of family ties and patriotism to return to the canton where he had pa.s.sed his earlier years. But he had cast in his lot with the Neuchatelois and was proof against all arguments. He remained faithful to the post he had chosen until he left it, temporarily as he then believed, to come to America. The citizens of his adopted town expressed their appreciation of his loyalty to them in a warm letter of thanks, begging, at the same time, his acceptance of the sum of six thousand francs, payable by installments during three years.

The summer of 1837 was a sad one to Aga.s.siz and to his whole family; his father died at Concise, carried off by a fever while still a comparatively young man. The pretty parsonage, to which they were so much attached, pa.s.sed into other hands, and thenceforward the home of Madame Aga.s.siz was with her children, among whom she divided her time.

In 1838 Aga.s.siz founded a lithographic printing establishment in Neuchatel, which was carried on for many years under his direction.

Thus far his plates had been lithographed in Munich. Their execution at such a distance involved constant annoyance, and sometimes great waste of time and money, in sending the proofs to and fro for correction. The scheme of establis.h.i.+ng a lithographic press, to be in a great degree at his charge, was certainly an imprudent one for a poor man; but Aga.s.siz hoped not only to facilitate his own publications by this means, but also to raise the standard of execution in works of a purely scientific character. Supported partly by his own exertions, partly by the generosity of others, the establishment was almost exclusively dependent upon him for its unceasing activity. He was fortunate in securing for its head M. Hercule Nicolet, a very able lithographic artist, who had had much experience in engraving objects of natural history, and was specially versed in the recently invented art of chromatic lithography.

Aga.s.siz was now driving all his steeds abreast. Beside his duties as professor, he was printing at the same time his "Fossil Fishes,"

his "Fresh-Water Fishes," and his investigations on fossil Echinoderms and Mollusks,--the ill.u.s.trations for all these various works being under his daily supervision. The execution of these plates, under M. Nicolet's care, was admirable for the period.

Professor Arnold Guyot, in his memoir of Aga.s.siz, says of the plates for the "Fresh-Water Fishes": "We wonder at their beauty, and at their perfection of color and outline, when we remember that they were almost the first essays of the newly-invented art of lithochromy, produced at a time when France and Belgium were showering rewards on very inferior work of the kind, as the foremost specimens of progress in the art."

All this work could hardly be carried on single handed. In 1837 M.

Edouard Desor joined Aga.s.siz in Neuchatel, and became for many years his intimate a.s.sociate in scientific labors. A year or two later M. Charles Vogt also united himself to the band of investigators and artists who had cl.u.s.tered about Aga.s.siz as their central force. M. Ernest Favre says of this period of his life: "He displayed during these years an incredible energy, of which the history of science offers, perhaps, no other example."

Among his most important zoological researches at this time were those upon mollusks. His method of studying this cla.s.s was too original and too characteristic to be pa.s.sed by without notice. The science of conchology had heretofore been based almost wholly upon the study of the empty sh.e.l.ls. To Aga.s.siz this seemed superficial.

Longing to know more of the relation between the animal and its outer covering, he bethought himself that the inner moulding of the sh.e.l.l would give at least the form of its old inhabitant. For the practical work he engaged an admirable moulder, M. Stahl, who continued to be one of his staff at the lithographic establishment until he became permanently employed at the Jardin des Plantes.

With his help and that of M. Henri Ladame, professor of physics and chemistry at Neuchatel, who prepared the delicate metal alloys in which the first mould was taken, Aga.s.siz obtained casts in which the form of the animals belonging to the sh.e.l.ls was perfectly reproduced. This method has since pa.s.sed into universal use. By its aid he obtained a new means of ascertaining the relations between fossil and living mollusks. It was of vast service to him in preparing his "Etudes critiques sur les Mollusques fossiles,"--a quarto volume with nearly one hundred plates.

The following letter to Sir Philip Egerton gives some account of his undertakings at this time, and of the difficulties entailed upon him by their number and variety.

LOUIS AGa.s.sIZ TO SIR PHILIP EGERTON.

NEUCHATEL, August 10, 1838.

. . .These last months have been a time of trial to me, and I have been forced to give up my correspondence completely in order to meet the ever-increasing demands of my work. You know how difficult it is to find a quiet moment and an easy mind for writing, when one is pursued by printing or lithographic proofs, and forced besides to prepare unceasing occupation for numerous employees. Add to this the close research required by the work of editing, and you surely will find an excuse for my delay. I think I have already written you that in order to have everything under my own eye, I had founded a lithographic establishment at Neuchatel in the hope of avoiding in future the procrastinations to which my proofs were liable when the work was done at Munich. . .I hope that my new publications will be sufficiently well received to justify me in supporting an establishment unique of its kind, which I have founded solely in the interest of science and at the risk of my peace and my health. If I give you all these details, it is simply to explain my silence, which was caused not by pure negligence, but by the demands of an undertaking in the success of which my very existence is involved. . .This week I shall forward to the Secretary of the British a.s.sociation for the Advancement of Science all that I have been able to do thus far, being unable to bring it myself, as I had hoped. You would oblige me greatly if you would give a look at these different works, which may, I hope, have various claims on your interest. First, there is the tenth number of the "Fossil Fishes," though the whole supply of publisher's copies will only be sent a few weeks later. Then there are the seven first plates of my sea-urchins, engraved with much care and with many details. A third series of plates relates to critical studies on fossil mollusks, little or erroneously known, and on their internal casts. This is a quite novel side of the study of sh.e.l.ls, and will throw light on the organization of animals known hitherto only by the sh.e.l.l. I have made a plaster collection of them for the Geological Society. They have been packed some time, but my late journey to Paris has prevented me from forwarding them till now. As soon as I have a moment, I shall make out the catalogue and send it on. When you go to London, do not fail to examine them; the result is curious enough. Finally, the plates for the first number of my "Fresh-Water Fishes" are in great part finished, and also included in my package for Newcastle. . .The plates are executed by a new process, and printed in various tints on different stones, resulting in a remarkable uniformity of coloring in all the impressions. . .

Such are the new credentials with which I present myself, as I bring my thanks for the honor paid to me by my nomination for the vacancy in the Royal Society of London. If unbounded devotion to the interests of science const.i.tuted a sufficient t.i.tle to such a distinction, I should be the less surprised at the announcement contained in your last letter. The action of the Royal Society, so flattering to the candidate of your choice, has satisfied a desire which I should hardly have dared to form for many a year,--that of becoming a member of a body so ill.u.s.trious as the Royal Society of London. . .

Each time I write I wish I could close with the hope of seeing you soon; but I must work incessantly; that is my lot, and the happiness I find in it gives a charm to my occupations however numerous they may be. . .

While Aga.s.siz's various zoological works were thus pressed with unceasing activity, the glaciers and their attendant phenomena, which had so captivated his imagination, were ever present to his thought. In August of the year 1838, a year after he had announced at the meeting of the Helvetic Society his comprehensive theory respecting the action of ice over the whole northern hemisphere, he made two important excursions in the Alps. The first was to the valley of Ha.s.sli, the second to the glaciers of Mont Blanc. In both he was accompanied by his scientific collaborator, M. Desor, whose intrepidity and ardor hardly fell short of his own; by Mr. d.i.n.kel as artist, and by one or two students and friends. These excursions were a kind of prelude to his more prolonged sojourns on the Alps, and to the series of observations carried on by him and his companions, which attracted so much attention in later years. But though Aga.s.siz carried with him, on these first explorations, only the simplest means of investigation and experiment, they were no amateur excursions. On these first Alpine journeys he had in his mind the sketch he meant to fill out. The significance of the phenomena was already clear to him. What he sought was the connection. Following the same comparative method, he intended to track the footsteps of the ice as he had gathered and put together the fragments of his fossil fishes, till the scattered facts should fall into their natural order once more and tell their story from beginning to end.

In his explorations of 1838 he found everywhere the same phenomena; the grooved and polished and graven surfaces and the rounded and modeled rocks, often lying far above and beyond the present limits of the glaciers; the old moraines, long deserted by the ice, but defining its ancient frontiers; the erratic blocks, transported far from their place of origin and disposed in an order and position unexplained by the agency of water.

These excursions, though not without their dangers and fatigues, were full of charm for men who, however serious their aims, were still young enough to enter like boys into the spirit of adventure.

Aga.s.siz himself was but thirty-one; an ardent pedestrian, he delighted in feats of walking and climbing. His friend d.i.n.kel relates that one day, while pausing at Grindelwald for refreshment, they met an elderly traveler who asked him, after listening awhile to their gay talk, in which appeals were constantly made to "Aga.s.siz," if that was perhaps the son of the celebrated professor of Neuchatel. The answer amazed him; he could hardly believe that the young man before him was the naturalist of European reputation.

In connection with this journey occurs the first attempt at an English letter found among Aga.s.siz's papers. It is addressed to Buckland, and contains this pa.s.sage: "Since I saw the glaciers I am quite of a snowy humor, and will have the whole surface of the earth covered with ice, and the whole prior creation dead by cold.

In fact, I am quite satisfied that ice must be taken [included] in every complete explanation of the last changes which occurred at the surface of Europe." Considered in connection with their subsequent work together in the ancient ice-beds and moraines of England, Scotland, Ireland, and Wales, it is curious to find Buckland answering: "I am sorry that I cannot entirely adopt the new theory you advocate to explain transported blocks by moraines; for supposing it adequate to explain the phenomena of Switzerland, it would not apply to the granite blocks and transported gravel of England, which I can only explain by referring to currents of water." During the same summer Mrs. Buckland writes from Interlaken, in the course of a journey in Switzerland with her husband. . ."We have made a good tour of the Oberland and have seen glaciers, etc., but Dr. Buckland is as far as ever from agreeing with you." We shall see hereafter how completely he became a convert to Aga.s.siz's glacial theory in its widest acceptation.

One friend, scarcely mentioned thus far in this biography, was yet, from the beginning, the close a.s.sociate of Aga.s.siz's glacier work.

Arnold Guyot and he had been friends from boyhood. Their university life separated them for a time, Guyot being at Berlin while Aga.s.siz was at Munich, and they became colleagues at Neuchatel only after Aga.s.siz had been for some years established there. From that time forward there was hardly any break in their intercourse; they came to America at about the same time, and finally settled as professors, the one at Harvard College, in Cambridge, Ma.s.sachusetts, and the other at the College of New Jersey, in Princeton. They shared all their scientific interests; and when they were both old men, Guyot brought to Aga.s.siz's final undertaking, the establishment of a summer school at Penikese, a cooperation as active and affectionate as that he had given in his youth to his friend's scheme for establis.h.i.+ng a permanent scientific summer station in the high Alps.

In a short visit made by Aga.s.siz to Paris in the spring of 1838 he unfolded his whole plan to Guyot, then residing there, and persuaded him to undertake a certain part of the investigation.

During this very summer of 1838, therefore, while Aga.s.siz was tracing the ancient limits of the ice in the Bernese Oberland and the Haut Valais, and later, in the valley of Chamounix, Guyot was studying the structure and movement of the ice during a six weeks'

tour in the central Alps. At the conclusion of their respective journeys they met to compare notes, at the session of the Geological Society of France, at Porrentruy, where Aga.s.siz made a report upon the general results of his summer's work; while Guyot read a paper, the contents of which have never been fully published, upon the movement of glaciers and upon their internal features, including the laminated structure of the ice, the so-called blue bands, deep down in the ma.s.s of the glacier.* (* See "Memoir of Louis Aga.s.siz" by Arnold Guyot, written for the United States National Academy of Sciences, page 38.) In the succeeding years of their glacial researches together, Guyot took for his share the more special geological problems, the distribution of erratic boulders and of the glacial drift, as connected with the ancient extension of the glaciers. This led him away from the central station of observation to remoter valleys on the northern and southern slopes of the Alps, where he followed the descent of the glacial phenomena to the plains of central Europe on the one side and to those of northern Italy on the other. We therefore seldom hear of him with the band of workers who finally settled on the glacier of the Aar, because his share of the undertaking became a more isolated one. It was nevertheless an integral part of the original scheme, which was carried on connectedly to the end, the results of the work in the different departments being constantly reported and compared. So much was this the case, that the intention of Aga.s.siz had been to embody the whole in a publication, the first part of which should contain the glacial system of Aga.s.siz; the second the Alpine erratics, by Guyot; while the third and final portion, by E. Desor, should treat of the erratic phenomena outside of Switzerland. The first volume alone was completed. Unlooked for circ.u.mstances made the continuation of the work impossible, and the five thousand specimens of the erratic rocks of Switzerland collected by Professor Guyot, in preparation for his part of the publication, are now deposited in the College of New Jersey, at Princeton.

In the following summer of 1839 Aga.s.siz took the chain of Monte Rosa and Matterhorn as the field of a larger and more systematic observation. On this occasion, the usual party consisting of Aga.s.siz, Desor, M. Bettanier, an artist, and two or three other friends, was joined by the geologist Studer. Up to this time he had been a powerful opponent of Aga.s.siz's views, and his conversion to the glacial theory during this excursion was looked upon by them all as a victory greater than any gained over the regions of ice and snow. Some account of this journey occurs in the following letter.

LOUIS AGa.s.sIZ TO SIR PHILIP EGERTON.

NEUCHATEL, September 10, 1839.

. . .Under these circ.u.mstances, I thought I could not do better than to pa.s.s 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, establis.h.i.+ng 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 astonis.h.i.+ng 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 pa.s.sed 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 Aga.s.siz 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 creva.s.ses, 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 Aga.s.siz, "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 sh.o.r.e (if, indeed, it was reached by them), were met only by the breath of the winter from the north and the thunders of the creva.s.ses 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 Aga.s.siz'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 Aga.s.siz 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 s.p.a.ce 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 Aga.s.siz, 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,--Aga.s.siz himself, a.s.sisted 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 Aga.s.siz's "Systeme Glaciaire". These results are also recorded in a volume ent.i.tled "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 Aga.s.siz 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 companions.h.i.+p and a.s.sistance 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 Aga.s.siz'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."

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 ma.s.ses 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 pa.s.sed 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 gra.s.s, served us as a road and brought us to the glacier of the Grindelwald. To reach the glacier itself we traversed a creva.s.se 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, Aga.s.siz 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.

Aga.s.siz 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 a.s.sociation at Glasgow, at which they were both present, was over, they started together for the Highlands. In a lecture delivered by Aga.s.siz, 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, Aga.s.siz found, as he had antic.i.p.ated, 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 Aga.s.siz, these parallel terraces explained themselves as the sh.o.r.es 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 Aga.s.siz 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 ent.i.tled "Parallel Roads of Glen Roy, in Scotland," in the second volume of Aga.s.siz's "Geological Sketches".) The glacial action in the whole neighborhood was such as to leave no doubt in the mind of Aga.s.siz 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.