It was he who explored Ethiopia and the southern parts of Africa, and brought back not only the curious fauna to his zoological gardens, but the first knowledge of the Troglodytes for men of science. The cultivation of science and of letters too was so remarkably one of his pursuits that the progress of the Alexandria of his day forms an epoch in the world's history, and we must separate his University and its professors from this summary, and devote to them a separate section. … The history of the organization of the University and its staff is covered with almost impenetrable mist. For the Museum and Library were in the strictest sense what we should now call an University, and one, too, of the Oxford type, where learned men were invited to take Fellowships, and spend their learned leisure close to observatories in science, and a great library of books. Like the mediæval universities, this endowment of research naturally turned into an engine for teaching, as all who desired knowledge flocked to such a centre, and persuaded the Fellow to become a Tutor. The model came from Athens. There the schools, beginning with the Academy of Plato, had a fixed property—a home with its surrounding garden, and in order to make this foundation sure, it was made a shrine where the Muses were worshipped, and where the head of the school, or a priest appointed, performed stated sacrifices. This, then, being held in trust by the successors of the donor, who bequeathed it; to them, was a property which it would have been sacrilegious to invade, and so the title Museum arose for a school of learning. Demetrius the Phalerean, the friend and protector of Theophrastus, brought this idea with him to Alexandria, when his namesake drove him into exile [see GREECE: B. C. 307-197] and it was no doubt his advice to the first Ptolemy which originated the great foundation, though Philadelphus, who again exiled Demetrius, gets the credit of it. The pupil of Aristotle moreover impressed on the king the necessity of storing up in one central repository all that the world knew or could produce, in order to ascertain the laws of things from a proper analysis of detail. Hence was founded not only the great library, which in those days had a thousand times the value a great library has now, but also observatories, zoological gardens, collections of exotic plants, and of other new and strange things brought by exploring expeditions from the furthest regions of Arabia and Africa. This library and museum proved indeed a home for the Muses, and about it a most brilliant group of students in literature and science was formed. The successive librarians were Zenodotus, the grammarian or critic; Callimachus, to whose poems we shall presently return; Eratosthenes, the astronomer, who originated the process by which the size of the earth is determined