work was, of course, written in Latin, according to the custom of
the time; but it is said that, when not employing that language,
he always wrote in German. The disputed nationality of Copernicus
strongly suggests that he came of a mixed racial lineage, and we
are reminded again of the influences of those ethnical minglings
to which we have previously more than once referred. The
acknowledged centres of civilization towards the close of the
fifteenth century were Italy and Spain. Therefore, the birthplace
of Copernicus lay almost at the confines of civilization,
reminding us of that earlier period when Greece was the centre of
culture, but when the great Greek thinkers were born in Asia
Minor and in Italy.

As a young man, Copernicus made his way to Vienna to study
medicine, and subsequently he journeyed into Italy and remained
there many years, About the year 1500 he held the chair of
mathematics in a college at Rome. Subsequently he returned to his
native land and passed his remaining years there, dying at
Domkerr, in Frauenburg, East Prussia, in the year 1543.

It would appear that Copernicus conceived the idea of the
heliocentric system of the universe while he was a comparatively
young man, since in the introduction to his great work, which he
addressed to Pope Paul III., he states that he has pondered his
system not merely nine years, in accordance with the maxim of
Horace, but well into the fourth period of nine years. Throughout
a considerable portion of this period the great work of
Copernicus was in manuscript, but it was not published until the
year of his death. The reasons for the delay are not very fully
established. Copernicus undoubtedly taught his system throughout