# COPERNICUS (Nicholas)

, an eminent astronomer, was born at Thorn in Prussia, January 19, 1473. He was instructed in the Latin and Greek languages at home; and afterward sent to Cracow, where he studied philosophy, mathematics, and medicine: though his genius was naturally turned to mathematics, which he chiesly studied, and purfued through all its various branches.

He set out for Italy at 23 years of age; stopping at Bologna, that he might converse with the celebrated astronomer of that place, Dominic Maria, whom he assisted for some time in making his observations. From hence he passed to Rome, where he was presently considered as not inferior to the famous Regiomontanus. Here he soon acquired so great a reputation, that he was chosen professor of mathematics, which he taught there for a long time with the greatest applause; and here also he made some astronomical observations about the year 1500.

Afterward, returning to his own country, he began to apply his fund of observations and mathematical knowledge, to correcting the system of astronomy which then prevailed. He set about collecting all the books that had been written by philosophers and astronomers, and to examine all the various hypotheses they had invented for the solution of the celestial phenomena; to try if a more symmetrical order and constitution of the parts of the world could not be discovered, and a more just and exquisite harmony in its motions established, than what the astronomers of those times so easily admitted. But of all their hypotheses, none pleased him so well as the Pythagorean, which made the sun to be the centre of the system, and supposed the earth to move both round the sun, and also round its own axis. He thought he discerned much beautiful order and proportion in this; and that all the embarrassment and perplexity, from epicycles and excentries, which attended the Ptolemaic hypotheses, would here be entirely removed.

This system he began to consider, and to write upon, when he was about 35 years of age. He carefully contemplated the phenomena; made mathematical calculations; examined the observations of the antients, and made new ones of his own; till, after more than 20 years chiefly spent in this manner, he brought his scheme to perfection, establishing that system of the world which goes by his name, and is now universally received by all philosophers.

This system however was at first looked upon as a most dangerous heresy, and his work had long been finished and perfected, before he could be prevailed upon to give it to the world, being strongly urged to it by his friends. At length yielding to their intreaties, it was printed, and he had but just received a perfect copy, when he died the 24th of May 1543, at 70 years of age; by which it is probable he was happily relieved from the violent fanatical persecutions of the church, which were but too likely to follow the publication of his astronomical opinions; and which indeed was afterward the sate of Galileo, for adopting and defending them.

The above work of Copernicus, first printed at Norimberg
in folio, 1543, and of which there have been
other editions since, is intitled *De Revolutionibus Orbium
Cælestium,* being a large body of astronomy, in 6 books.

When Rheticus, the disciple of our author, returned
out of Prussia, he brought with him a tract of Copernicus,
on plane and spherical trigonometry, which he
had printed at Norimberg, and which contained a table
of sines. It was afterward printed at the end of the
first book of the Revolutions. An edition of our author's
great work was also published in 4to at Amsterdam
in 1617, under the title of *Astronomia Instaurata,*
illustrated with notes by Nicolas Muler of Groningen.