De aequinoctiorum anticipatione diatriba. Nunc primum edita.Paris, Jérôme Drouart, 1613. 4to. With 5 woodcuts with astronomical diagrams in the text, a woodcut headpiece (pus 1 repeat) and 2 woodcut decorated initials (2 different series, the larger containing a portrait of an astronomer). Contemporary flexible sheepskin parchment,

[8], 96 pp.First edition, posthumously published, of a rare work on the shifting of the equinoxes due to the precession of the earth’s axis, written by the famous Leiden professor Josephus Justus Scaliger (1540-1609), edited by his student Janus Rutgersius (1589-1625), who lived in Paris until 1613 and who dedicated this work to Pierre Dupuy, one of the Paris scholars with whom Rutgersius was on friendly terms. His dedicatory letter on ã2r-3v is dated from Paris, 23 May 1613. After Scaliger's work follows an excerpt of his letter to David Rivaldus, dated Leiden, 16 April 1604, on pp. 91-96. The larger of the two initials shows (inside the letter Q) what appears to be a hunchbacked astronomer with two globes, a book and other items.Scaliger put the study of ancient chronology on a scholarly footing by studying not only Christian, Greek and Roman chronology, but also Jewish, Islamic, Babylonian and Egyptian chronology and comparing them, culminating in his most famous work, De emendatione temporum (1583). This helped to correct Christian chronology and supported the new Gregorian calendar introduced in the previous year. Even in the corrected calendar, however, the dates of the equinoxes had shifted by several days since the birth of Christ due to the precession of the earth’s axis, so that in Jesus’s time the winter solstice would have been on or near 25 December, possibly the reason that date was later chosen to celebrate his birth.Manuscript owner's inscription on the title-page: “Ex Bibl. Guil. DeWal”(?). Very good and clean copy.l Bernays, Joseph Justus Scaliger (1855), item XXXIII (p. 301); Picarta (1 copy: Leiden UL); Smitskamp, Scaliger collection 162 (“extremely rare”); USTC 6016345.