It must not be thought, however, that the Jesuits were interested only in astronomy. They had a large number of mathematicians and of teachers of all the physical sciences. The famous Roman College, founded in St. Ignatius' time, was always looked up to as the type of what a Jesuit College should be. It was here that the great scholarly Father Kircher taught for nearly half of the seventeenth century. He was invited to Rome to begin his teaching there just {219} before the condemnation of Galileo. He would not have received the invitation had there been the slightest feeling of opposition on the part of the Church or his order to the teaching of science. While teaching at the Roman College he wrote a series of text-books on all phases of physical science. There are several text-books on magnetism, one on light, a second on sound, a third on astronomy, a fourth on the subterranean world and many others. It would be easy to think that these books are mere compilations and that they were probably scarcely more than small hand-books of the imperfect knowledge of the time. On the contrary, they are magnificent large volumes beautifully printed, finely illustrated, bibliographic treasures full of original observation. They are some of the best text-books ever issued. Father Kircher's originality is demonstrated by the fact that he is the perfecter of the projecting stereoscope or magic lantern, which he was led to invent in his desire to be able to make demonstrations to his classes. He also founded the Kircherian Museum, by which the teaching of anthropology and ethnology were greatly furthered through the curiosities sent to Rome by the Jesuit missionaries all over the world. His book, "On the Pest," is full of observations of great value and contains the first suggestions that infectious diseases are carried by insects. There was no subject that he touched that he did not illuminate. Since that time there have been many distinguished Jesuit scientists, and they have continued their work down to our own day. At the present time, one of the best known of biologists in the special field of entomology is Father Wasmann, S.J., who has published some seven hundred papers on ants, their hosts and guests, and who, taking advantage of the help of his brethren all over the world, has described many hundreds of new species. How successful the Jesuits have been in their pursuit of science will perhaps be best realized from the fact that, while in Poggendorff's "Biographical Dictionary of Science" out of something less than nine thousand names nearly one thousand are Catholic clergymen, about five hundred of these are Jesuits. Their occupations first of all as priests often left them but little leisure {220} for scientific investigations, and yet they succeeded in stamping their names upon the history of science.