# Sacro Bosco, Johannes De

**SACRO BOSCO, JOHANNES DE** [JOHN HOLYWOOD] (d. 1244 or 1256), astronomical author, studied at Oxford and was afterwards professor of
mathematics at the university of Paris. He wrote a treatise on spherical astronomy, Tractalus de sphaera, first printed at Ferrara in 1472. This was the second
astronomical work to be printed. Although recording no advance on the Arabian commentaries on Ptolemy, it gained a great reputation; twenty-four editions
appeared before 1500, and at least forty between 1500 and 1647, in which year the last edition was published at Leiden. About the year 1232 he wrote De anni
ratione or De compute eccksiastico (printed editions at Paris in 1538 (?), 1550, 1572 and at Antwerp in 1547 and 1566), in which he points out the increasing
error of the Julian calendar, and suggests a remedy which is nearly the same as that actually used under Gregory XIII. three hundred and fifty years later.

He also wrote Algorismus or De arle numerandi, printed in 1490 (?), in 1517 (Vienna), 1521 (Cracow), 1523 (Venice); De astrolabio and Breviarum juris.

*Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)*