In the autumn of 1830 Agassiz left Munich, and after a short visit in Vienna, where he found himself “received as a scientific man for whom no letters of recommendation were necessary,” he returned to Switzerland and the welcome of his proud parents. But it was hard to adjust himself to the quiet village by Lake Morat, and, although money was difficult to secure, a visit to Paris was finally made possible through the generosity of a friend of the family. Here Agassiz formed important friendships with two of the greatest scientists of the age: Cuvier, the leading French zoölogist, and Alexander von Humboldt, the leader of the scientific world.
The years that immediately followed were filled with scientific progress. The “Brazilian Fishes” had determined Agassiz’s specialty, and the reputation of the book led him to plan a history of the fresh-water fishes of Central Europe, including a natural history of fossil fishes. It was an enormous undertaking, for palæontology was a new science, involving the study of fossil specimens scattered through the museums of Europe. But Agassiz foresaw only the value which science would place on such a work, and the five volumes were finally published by him, at intervals, from 1833 to 1843.
Life in Paris soon proved difficult for the young scientist, and his poverty was particularly noticeable, for here there was wealth and position even among scientific men. He had only forty dollars a month, and his clothing had become so worn that it was not possible for him to accept invitations from well-to-do friends. The position of professor of natural history at Neuchâtel was offered him, and, although the salary was only $400 a year, it seemed wise to accept. His acceptance, and with it the close of his year in Paris, marks the end of his boyhood and student days. A new period awaited him.
The college of Neuchâtel was small and unimportant. The chair of natural history was new, and there was no scientific apparatus, museum, or lecture-room. But this mattered little to the young professor. Soon after his arrival he founded a Natural History Society among the leading citizens of the town; his lectures were given in the city hall, and his own collection formed the nucleus of a natural history museum.
As in college, so in the quiet Swiss village, Agassiz soon gathered about him a group of scientific men as his students and assistants, many of whom in later life became themselves naturalists of reputation. It was a “scientific factory” of which Agassiz was the mainspring. He was poor, but somehow he managed to go on, supporting many of his staff in his own house, printing and lithographing his own publications, and supporting his own family as well, for his marriage had now brought additional responsibilities upon his broad shoulders. It was an unstable basis, but in one way or another Agassiz found the means to proceed. Money was but the means to an end, never the end itself. “I cannot spend my time in making money!” he once said when a profitable business offer was made to him. The remark expressed clearly his firm devotion to his chosen profession.
It was during this period of his life that Agassiz added to scientific knowledge the proof that at some remote time in the earth’s existence vast glaciers, moving fields of ice miles in area and often hundreds of feet in thickness, had played a part in the earth’s formation almost as important as the recognized agents, fire and water. It was a geological discovery the proof of which, although indisputable, seemed so startling, that it was with difficulty that it was accepted even by the best scientific minds of the day.
In the Alpine country had been found great boulders dropped apparently by some strange force in fields far from the quarries of native rock from which they had been torn. Here also were moraines and dikes, great piles of loose gravel deposited by some unknown agency; and here also, where the bedrock was visible, could be seen deep furrows and scratches on the polished stone as if chiseled by a giant tool.
Glaciers existed in the Alps, but it was hard for men to believe that glaciers had once existed where now were green fields and meadows. But Agassiz was not the man to endeavor to found a belief on unsupported theory, and only after six years of study of the glaciers and glacial traces in the Alps and actual observations on the glacier of the Aar, was he prepared to give his proofs of the theory to the scientific world.
Basing his demonstration on this accumulated evidence, Agassiz proved that at one time glaciers had covered a large part of the now civilized world. The great boulders had been scooped up by them in their progress, and perhaps some thousands of years later had been dropped a hundred miles away by the melting ice-sheet. So also had the masses of gravel been carried far from their sources, to form strange new glacial deposits. And on the scarred and grooved rocks was the final evidence; for these deep scratches had surely been ground by the advancing glacier as it slowly and silently moved onward. “The idea that such phenomena were not restricted to regions where glaciers now are found, but that traces of glacial action could be seen over enormous tracts of the earth’s surface, perhaps including regions in the tropics, and that in countries now temperate there might be discovered, not only the remains of tropical fauna and flora, but also distinct indications of a period of arctic cold—this was as new as startling.”
During the years of his professorship at Neuchâtel, Agassiz published many important contributions to scientific knowledge in those particular departments of natural science to which he had devoted himself. At the same time came also many honors, including offers of professorships from the universities of Geneva and Lausanne, and the award of the Wollaston Medal by the Geographical Society of London.