torical scientific study [Footnote 2] of the great
founder of modern astronomy. The book has been reviewed, criticized
and discussed very thoroughly since then, and has been translated into
several languages. The latest translation was into Italian, the work
of Father Pietro Mezzetti, S.J., [Footnote 3] and was published in
Rome at the end of 1902--having had the benefit {23} of the author's
revision. The historical details, then, of Copernicus's life may be
considered to have been cast into definite shape, and his career may
be appreciated with confidence as to the absolute accuracy and
essential significance of all its features.

[Footnote 1: _History of the German People at the Close of the
Middle Ages_. By Johannes Janssen Translated from the German by M A
Mitchell and A M Christie. Vol I, p. 3.]

[Footnote 2: _Nikolaus Kopernicus, Der Altmeister der neueren
Astronomie, Ein Lebens und Kultur Bild_. Von Adolf Muller, S.J.]

[Footnote 3: Professor of Astronomy and Physics at the Pontifical
Leonine College of Anagni]

Nicholas Copernicus--to give him the Latin and more usual form of his
name--was the youngest of four children of Niclas Copernigk, who
removed from Cracow in Poland to Thorn in East Prussia (though then a
city of Poland), where he married Barbara Watzelrode, a daughter of
one of the oldest and wealthiest families of the province. His
mother's brother, after having been a canon for many years in the
cathedral of Frauenburg, was elected Bishop of the Province of
Ermland. The future astronomer was born in 1473, at a time when Thorn,
after having been for over two hundred years under the rule of the
Teutonic Knights, had for some seven years been under the dominion of
the King of Poland. There were two boys and two girls in the family;
and their fervent Catholicity can be judged from the fact that all of
them, parents and children, were inscribed among the members of the
Third Order of St. Dominic. Barbara, the older sister, became a
religious in the Cistercian Convent of Kulm, of which her aunt
Catherine was abbess, and of which later on she herself became abbess.
Andrew, the oldest son, became a priest; and Nicholas, the subject of
this sketch, at least assumed, as we shall see, all the {24}
obligations of the ecclesiastical life, though it is not certain that
he received the major religious orders.

Copernicus's collegiate education was obtained at the University of
Cracow, at