ees or
127 degrees, so that his measurement is wrong by one third of the whole,
one-sixth for the error in the measurement of a degree and one-sixth for
the errors in measuring the distance geometrically. These errors, owing
to the authority attributed to the geography of Ptolemy in the Middle
Ages, produced a consequence of the greatest importance. They really led
to the discovery of America. For the design of Columbus to sail from the
west of Europe to the east of Asia was founded on the supposition that
the distance was less by one third than it really was." This view is
perhaps a trifle fanciful, since there is nothing to suggest that the
courage of Columbus would have balked at the greater distance, and since
the protests of the sailors, which nearly thwarted his efforts, were
made long before the distance as estimated by Ptolemy had been covered;
nevertheless it is interesting to recall that the great geographical
doctrines, upon which Columbus must chiefly have based his arguments,
had been before the world in an authoritative form practically unheeded
for more than twelve hundred years, awaiting a champion with courage
enough to put them to the test.

GALEN--THE LAST GREAT ALEXANDRIAN

There is one other field of scientific investigation to which we must
give brief attention before leaving the antique world. This is the field
of physiology and medicine. In considering it we shall have to do
with the very last great scientist of the Alexandrian school. This was
Claudius Galenus, commonly known as Galen, a man whose fame was destined
to eclipse that of all other physicians of antiquity except Hippocrates,
and whose doctrines were to have the same force in their field
throughout the Middle Ages that the doctrines of Aristotle had for
physical science. But before we take up Galen's specific labors, it will
be well to inquire briefly as to the state of medical art and science in
the Roman world at the time when the last great physician of antiquity
came upon the scene.

The Romans, it would appear, had done little in the way of scientific
discoveries in the field of medicine, but, nevertheless, with their
practicality of mind, they had turned to better account many more of
the scientific discoveries of the Greeks than did the discoverers
themselves. The practising physicians in early Rome were mostly men of
Greek origin, who came to the capital after the overthrow of the Greeks
by the Romans. Many of them were s