Effigies Tychonis Brahe O.F. Aedificii et Instrumentorum Astronomicorum structoris. A. Domini 1587, Aetatis Sue 40

Joan Blaeu was one of the leading Amsterdam atlas publishers of the seventeenth century, and his Atlas Maior incorporated not only maps but also engraved material presenting astronomy, cosmography, and learned geography. This plate differs from his continental and regional title pages by introducing Tycho Brahe’s astronomical instruments rather than a geographic region. Willem Jansz. Blaeu, Joan Blaeu’s father, studied with Brahe on the island of Hven between 1594 and 1596, and this engraving draws directly on illustrations first published in Brahe’s Astronomiae instauratae mechanica (1598).

The composition presents Brahe within the observational environment of Uraniborg, his purpose-built astronomical complex. The scene is arranged across several levels. At the top, a parapet and landscape carry the Latin caption identifying Tycho Brahe as "Otto’s son, " builder of the observatory and its astronomical instruments in 1587 at the age of forty. The upper terrace shows four instruments in use by assistants. Below, two chambers divided by a celestial globe contain tables and scribes at work, while the lowest level shows a laboratory with numbered instruments and a figure tending a furnace. To the right, an observer at point F views the Sun through an opening in the wall (A), announcing its passage across the meridian (R). A second observer, holding a torch, records the time on a precision clock, while a scribe notes the result. Brahe sits at his table with compass and ruler, pointing upward to connect mathematical measurement with celestial observation.

Behind Brahe are shelves of books and medallions of King Frederick II of Denmark (Z) and Queen Sophie (Y), his patrons. A globe (X) in a wall niche is identified by Brahe as a gift to their son, Christian IV, during a royal visit to Hven. At Brahe’s feet lies his dog, described by him as "his most loyal companion."

The collection also holds several other Joan Blaeu title pages, including the general title page (157), and title pages for the Arctic (284), Europe (151), Africa (149), America (150), and Asia/China (152).