dian angel to
protect him from the evil spirits that occasionally broke out of Hell
and came up to earth to tempt men.

Mathematics knows nothing of angels--it only knows what it can prove.
Copernicus believed that, if certain stars did move, they moved by some
unalterable law of their own. In riding on a boat he observed that the
shores seemed to be moving past, and he concluded that a part, at least,
of the seeming movements of planets might possibly be caused by the
moving of the earth.

In talking with astrologers he perceived that very seldom did they know
anything of mathematics. And this ignorance on their part caused him to
doubt them entirely.

His faith was in mathematics--the thing that could be proved--and he
came to the conclusion that astronomy and mathematics were one thing,
and astrology and child-stories another.

He remained at Bologna just long enough to turn the astrologers out of
the society of astronomers.

Novarra's lectures on astronomy were given in Latin, and in truth all
learning was locked up in this tongue. But astrology and the theological
fairy-tales of the people floated free. They were a part of the vagrant
hagiology of the roadside preachers, who with lurid imaginations said
the things they thought would help carry conviction home and make
"believers."

From Bologna Copernicus then moved on to Padua, where he remained two
years, teaching and giving lectures. Here he devoted considerable time
to chemistry, and on leaving he was honored by being given a degree by
the University. Next we find him at Rome, a professor in mathematics and
also giving lectures on chemistry. His lectures were not for the
populace--they were for the learned few. But they attracted the
attention of the best, and were commented upon and quoted by the various
other teachers, preachers and lecturers. A daring thinker who expresses
himself without reservation states the things that various others know
and would like to state if they dared. It is often very convenient when
you want a thing said to enclose the matter in quotation-marks. It
relieves one from the responsibility of standing sponsor for it, if the
hypothesis does not prove popular.

Copernicus was only nineteen years old when Columbus discovered America,
but it seems he did not hear of Columbus until he reached Bologna in
Fourteen Hundred Ninety-five. At Rome he made various references to
Columbus in his lectures; dwelt upon the truth that the ear