Chapter 19: 1860-1863: Aet. 53-56.
- Return to Cambridge. -- removal of collection to New Museum building. -- distribution of work. -- relations with his students. -- breaking out of the war between North and South. -- interest of Agassiz in the preservation of the Union. -- commencement of Museum publications. -- reception of third and fourth volumes of ‘contributions.’ -- Copley Medal. -- general correspondence. -- lecturing tour in the West. -- circular letter concerning Anthropological collections. -- letter to Mr. Ticknor concerning geographical distribution of fishes in Spain.
On his return to Cambridge at the end of September, Agassiz found the Museum building well advanced. It was completed in the course of the next year, and the dedication took place on the 13th November, 1860. The transfer of the collections to their new and safe abode was made as rapidly as possible, and the work of developing the institution under these more favorable conditions moved steadily on. The lecture rooms were at once opened, not only to students but to other persons not connected with the university. Especially welcome were teachers of schools  for whom admittance was free. It was a great pleasure to Agassiz thus to renew and strengthen his connection with the teachers of the State, with whom, from the time of his arrival in this country, he had held most cordial relations, attending the Teachers' Institutes, visiting the normal schools, and associating himself actively, as far as he could, with the interests of public education in Massachusetts. From this time forward his college lectures were open to women as well as to men. He had great sympathy with the desire of women for larger and more various fields of study and work, and a certain number of women have always been employed as assistants at the Museum. The story of the next three years was one of unceasing but seemingly uneventful work. The daylight hours from nine or ten o'clock in the morning were spent, with the exception of the hour devoted to the school, at the Museum, not only in personal researches and in lecturing, but in organizing, distributing, and superintending the work of the laboratories, all of which was directed by him. Passing from bench to bench, from table to table, with a suggestion here, a kindly but scrutinizing glance there, he made his sympathetic presence  felt by the whole establishment. No man ever exercised a more genial personal influence over his students and assistants. His initiatory steps in teaching special students of natural history were not a little discouraging. Observation and comparison being in his opinion the intellectual tools most indispensable to the naturalist, his first lesson was one in looking. He gave no assistance; he simply left his student with the specimen, telling him to use his eyes diligently, and report upon what he saw. He returned from time to time to inquire after the beginner's progress, but he never asked him a leading question, never pointed out a single feature of the structure, never prompted an inference or a conclusion. This process lasted sometimes for days, the professor requiring the pupil not only to distinguish the various parts of the animal, but to detect also the relation of these details to more general typical features. His students still retain amusing reminiscences of their despair when thus confronted with their single specimen; no aid to be had from outside until they had wrung from it the secret of its structure. But all of them have recognized the fact that this one lesson in looking, which forced them to such careful scrutiny of the  object before them, influenced all their subsequent habits of observation, whatever field they might choose for their special subject of study. One of them who was intending to be an entomologist concludes a very clever and entertaining account of such a first lesson, entirely devoted to a single fish, with these words: ‘This was the best entomological lesson I ever had,—a lesson whose influence has extended to the details of every subsequent study; a legacy the professor has left to me, as he left it to many others, of inestimable value, which we could not buy, with which we could not part.’1 But if Agassiz, in order to develop independence and accuracy of observation, threw his students on their own resources at first, there was never a more generous teacher in the end than he. All his intellectual capital was thrown open to his pupils. His original material, his unpublished investigations, his most precious specimens, his drawings and illustrations were at their command. This liberality led in itself to a serviceable training, for he taught them to use with respect the valuable, often unique, objects intrusted to their care. Out of the intellectual goodlowship  which he established and encouraged in the laboratory grew the warmest relations between his students and himself. Many of them were deeply attached to him, and he was extremely dependent upon their sympathy and affection. By some among them he will never be forgotten. He is still their teacher and their friend, scarcely more absent from their work now than when the glow of his enthusiasm made itself felt in his personal presence. But to return to the distribution of his time in these busy days. Having passed, as we have seen, the greater part of the day in the Museum and the school, he had the hours of the night for writing, and rarely left his desk before one or two o'clock in the morning, or even later. His last two volumes of the ‘Contributions,’ upon the Acalephs, were completed during these years. In the mean time, the war between North and South had broken out, and no American cared more than he for the preservation of the Union and the institutions it represented. He felt that the task of those who served letters and science was to hold together the intellectual aims and resources of the country during this struggle for national existence, to fortify the strongholds  of learning, abating nothing of their efficiency, but keeping their armories bright against the return of peace, when the better weapons of civilization should again be in force. Toward this end he worked with renewed ardor, and while his friends urged him to suspend operations at the Museum and husband his resources until the storm should have passed over, he, on the contrary, stimulated its progress by every means in his power. Occasionally he was assisted by the Legislature, and early in this period an additional grant of ten thousand dollars was made to the Museum. With this grant was begun the series of illustrated publications already mentioned, known as the ‘Bulletin of the Museum of Comparative Zoology in Cambridge.’ During this period he urged also the foundation of a National Academy of Sciences, and was active in furthering its organization and incorporation (1863) by Congress. With respect to this effort, and to those he was at the same time making for the Museum, he was wont to recall the history of the University of Berlin. In an appeal to the people in behalf of the intellectual institutions of the United States during the early years of the war he says: ‘A well known fact in the history  of Germany has shown that the moment of political danger may be that in which the firmest foundations for the intellectual strength of a country may be laid. When in 1806, after the battle of Jena, the Prussian monarchy had been crushed and the king was despairing even of the existence of his realm, he planned the foundation of the University of Berlin, by the advice of Fichte, the philosopher. It was inaugurated the very year that the despondent monarch returned to his capital. Since that time it has been the greatest glory of the Prussian crown, and has made Berlin the intellectual centre of Germany.’ It may be added here as an evidence of Agassiz's faith in the institutions of the United States and in her intellectual progress that he was himself naturalized in the darkest hour of the war, when the final disruption of the country was confidently prophesied by her enemies. By formally becoming a citizen of the United States he desired to attest his personal confidence in the stability of her Constitution and the justice of her cause. Some light is thrown upon the work and incidents of these years by the following letters:— 
At about this time the Copley Medal was awarded to Agassiz, a distinction which was the subject of cordial congratulation from his English friends.
.  In a paper just read to the Geological Society Professor Ramsay has made a stronger demand on the powers of ice than you ever did. He imagines that every Swiss lake north and south (Geneva, Neuchatel, Como, etc.) has been scooped out, and the depressions excavated by the abrading action of the glaciers. . . .
As has been seen by a previous letter from Sir Roderick Murchison, Agassiz tried from time to time to give his English friends more just views of our national struggle. The letter to which the following is an answer is  missing, but one may easily infer its tenor, and the pleasure it had given him.
Agassiz had now his time more at his own disposal since he had given up his school and had completed also the fourth volume of his ‘Contributions.’ Leisure time he could never be said to have, but he was free to give all his spare time and strength to the Museum, and to this undivided aim, directly or indirectly, the remainder of his life was devoted. Although at intervals he received generous aid from the Legislature or from private individuals for the further development of the Museum, its growth outran such provision, and especially during the years of the war the problem of meeting expenses was often difficult of solution. To provide for such a contingency Agassiz made in the winter of 1863 the most extensive lecturing tour he  had ever undertaken, even in his busiest lecturing days. He visited all the large cities and some of the smaller towns from Buffalo to St. Louis. While very remunerative, and in many respects delightful, since he was received with the greatest cordiality, and lectured everywhere to enthusiastic crowds, this enterprise was, nevertheless, of doubtful economy even for his scientific aims. Agassiz was but fifty-six, yet his fine constitution began to show a fatigue hardly justified by his years, and the state of his health was already a source of serious anxiety to his friends. He returned much exhausted, and passed the summer at Nahant, where the climate always benefited him, while his laboratory afforded the best conditions for work. If this summer home had a fault, it was its want of remoteness. He was almost as much beset there, by the interruptions to which a man in his position is liable, as in Cambridge. His letters show how constantly during this nominal vacation his Museum and its interests occupied his thoughts. One is to his brother-in-law, Thomas G. Cary, whose residence was in San Francisco, and who had been for years his most efficient aid in obtaining collections from the Pacific Coast. 
The following letter to Mr. Ticknor is in the same spirit as previous ones to Mr. Haldeman and others, concerning the distribution of fishes in America. It is given at the risk of some repetition, because it illustrates Agassiz's favorite idea that a key to the original combination of faunae in any given system of fresh waters, might be reached through a closer study than has yet been possible of the geographical or local circumscription of their inhabitants.