This school opened by the helpful wife made Agassiz a free man—no longer shackled by that worst form of slavery, debt. Well said John Ruskin: "My first word to all men and boys who care to hear me is, don't get into debt. Starve and go to heaven, but don't borrow.... Don't buy things you can't pay for!"

Indefatigable, versatile, comprehensive in mind, Agassiz at once planned another great work, to be published in ten volumes, though it was finally reduced to four: "Contributions to the Natural History of the United States." Mr. Francis C. Gray of Boston, a personal friend and a lover of letters and science, set the subscription before the public. Very soon, to Agassiz's great delight, he received the names of seventeen hundred subscribers, at twelve dollars a volume.

He had now reached his fiftieth birthday, completing his first volume of the new work on that day. His students serenaded him, and Longfellow wrote, to be read at the "Saturday Club," composed of Hawthorne, Holmes, Lowell, Dana, and others, this exquisite poem:—

It was fifty years ago,
In the pleasant month of May,
In the beautiful Pays de Vaud,
A child in its cradle lay.
And Nature, the old nurse, took
The child upon her knee,
Saying: "Here is a story-book
Thy Father has written for thee."
"Come wander with me," she said,
"Into regions yet untrod,
And read what is still unread
In the manuscripts of God."
And he wandered away and away
With Nature, the dear old nurse,
Who sang to him night and day
The rhymes of the universe.
And whenever the way seemed long,
Or his heart began to fail,
She would sing a more wonderful song,
Or tell a more marvellous tale.
So she keeps him still a child,
And will not let him go,
Though at times his heart beats wild
For the beautiful Pays de Vaud;
Though at times he hears in his dreams
The Ranz des Vaches of old,
And the rush of mountain streams
From glaciers clear and cold;
And the mother at home says, "Hark!
For his voice I listen and yearn;
It is growing late and dark,
And my boy does not return!"

This year, 1857, Agassiz received an unexpected honor—a call to one of the most coveted places at the Jardin des Plantes; the chair of palæontology in the Museum of Natural History, Paris. Though obliged to refuse it because he considered his life-work to be in America, he appreciated the favor as also the bestowal of the Order of the Legion of Honor, and the Copley medal from England. Twenty-seven years before, he had received in Paris the aid of Humboldt in his destitution; now, two hemispheres competed for his services.

The following year, 1858, Mr. Francis C. Gray died, leaving fifty thousand dollars for the establishment of a Museum of Comparative Zoölogy, to be used neither for buildings nor for salaries, but purely for scientific needs.

"All things come round to him who will but wait," says Longfellow, in the "Falcon of Sir Federigo." Other gifts soon followed. Harvard University gave land for the site of the building. The Massachusetts Legislature gave lands to the amount of one hundred thousand dollars. Over seventy-one thousand was promptly subscribed by citizens of Boston and Cambridge. Agassiz contributed all his collections, worth thousands of dollars. The corner-stone of the museum was laid one sunny afternoon in June, 1859, and then the happy Agassiz hastened across the ocean, to rejoice with his mother, in her home near the foot of the Jura. She was glad and proud now that he had become a naturalist.

The museum was dedicated November 13, 1860. The plan included a main building 364 feet long, with wings 205 long, the whole enclosing a hollow square. The lecture rooms were at once opened. Especially welcome were teachers of schools, for whom admittance was free. His lectures were open to women as well as to men. This would naturally be expected, from the broad-mindedness of the man, and the respect he must have had for the capacity of woman, from such a mother and such a wife. "He had great sympathy," says Mrs. Agassiz, "with the desire of women for larger and more various fields of study and work." To such men women can never be too grateful.

In 1863, he helped to organize the National Academy of Sciences. He frequently gave lectures in the large cities, using the money for the further development of the museum.

In 1865 he started, with his wife and several assistants, for sixteen months of scientific investigation in Brazil, the expenses borne by his friend, Mr. Nathaniel Thayer, of Boston. He writes to his mother,—