Abstract
This article considers the function of twenty-two hand-colored prints of mathematical instruments in Tycho Brahe's Astronomiae instauratae mechanica (Instruments of the renewed astronomy; 1598), a hand-painted presentation treatise dedicated to Emperor Rudolf II and conferred on a network of individuals connected to the imperial court in Prague. Although the accompanying text communicates the instruments’ use and composition, the images demand close inspection because they articulate Brahe's observationally driven astronomy. They do so through structured, repeated, and consecutive representations; through expanded viewer access, achieved by adhering to multiple perspectives; through the juxtaposition of colors, which focuses attention on the heads of the instruments (the part that does the measuring); and through the use of gold paint, which emphasizes the head and brings to mind the very metallic nature of the instruments. Much like an astronomer taking multiple measurements of cosmological phenomena, these images allow viewers and readers, as they leaf through the pages of the treatise, to become virtual participants in Brahe's instauration of astronomy.