These drawings were made on pages 128 & 113, and pages 3 & 43 of a book on astronomy by Joannis de Sacro Bosco, Sphaera, Lyon France, 1564. The original pages were perforated by termite holes that were filled with gold leaf. The pages themselves have engravings and marginalia that Macia has incorporated into his new images. Macia related that he was inspired to make these drawings after visiting the Sackner Archive and viewing Tom Phillips' A Humument. -- Source of annotation: Marvin or Ruth Sackner.