Calendarium
Johannes Mueller, Regiomontanus (1435 – 1476)
Venice; Erhard Ratdolt, 1482
CE73 M8 1482

Regiomontanus’ Calendarium was first printed at his own press in Nuremberg in 1474. In 1476, master printer Erhard Ratdolt published it in Venice, the capital of Italian printing, followed by this edition in 1482. Regiomontanus was one of the first publishers of astronomical material. His Calendarium represents the first application of modern scientific methods of astronomical calculation and observation to the problems of the lunar calendar, such as Easter, and the accurate prediction of eclipses.Regiomontanus’ almanacs contained planetary positions for a particular year as calculated from astronomical tables, freeing astronomers from performing the laborious task themselves.

This edition also contains verses by J. Sentius in praise of the author, and by Santritter in praise of the printer. Santritter would later become a printer himself. The last two leaves of this book are printed on four pages of thick paper pasted together to form astronomical instruments. The ingenuity of the instruments demonstrates Ratdolt’s technical skill in overcoming the challenges posed by early scientific publishing. This edition was not only technically innovative but artistically elegant as well. The title page is ornamented with an intricate border. The title-page initial is printed in red and black. Other woodcut initials are printed in black and white. Ratdolt included imprint details – that is, the information which tells us when and by whom the book was printed – at the end of the opening verses on the verso of the title-page.