Petrus Apianus (14951552).
Ingolstadt: for the author, 1540
Rare Books Division, The New York Public Library
Purchased from the Bequest of Alexander Maitland
Until well into the
seventeenth century, the determination of appropriate bloodletting sites,
of childbirth times, and of the optimum time for the treatment of various
ailments required the accurate plotting of planetary conjunctions, eclipses,
and other astronomical phenomena. The Astronomicum caesareum provided
for this need in a magnificent book that combined elegant typography with
exquisite woodcuts and hand-coloring. For this book, Apianus created thirty-five
elaborate mechanical devices called volvelles whose multiple disks, pointers,
and string allowed the reader to accurately determine the position and
movement of the planets and other celestial phenomena.