Frank Preston Stearns, Cambridge Sketches

[29] deep-chested men, and of about the same height, with large, well-rounded heads; but Agassiz had an elastic French step, whereas Doctor Hill walked with something of a shuffle. One might even imagine Agassiz dancing a waltz. Lowell said of him that he was “emphatically a man, and that wherever he went he made a friend.” His broad forehead seemed to smile upon you while he was talking, and from his simple-hearted and genial manners you felt that he would be a friend whenever you wanted one. He was the busiest and at the same time one of the most accessible persons in the university.

On one occasion, happening to meet a number of students at the corner of University Building, one of them was bold enough to say to him: “Prof. Agassiz, would you be so good as to explain to us the difference between the stone of this building and that of Boylston Hall? We know that they are both granite, but they do not look alike.” Agassiz was delighted, and entertained them with a brief lecture on primeval rocks and the crust of the earth's surface. He told them that Boylston Hall was made of syenite; that most of the stone called granite in New England was syenite, and if they wanted to see genuine granite they should go to the tops of the White Mountains. Then looking at his watch he said: “Ah, I see I am ”