<p style='text-align: justify;'>Having lost the favour of the Danish court in the latter years of the sixteenth century, Tycho Brahe published his <i>Astronomiae instauratae mechanica</i> in 1598 as part of a strategy to procure royal patronage elsewhere. Addressed to his eventual patron, Holy Roman Emperor Rudolph II, the work lavishly described and illustrated the innovative astronomical instruments that Tycho had designed and constructed on the island of Hven, the site of his astronomical programme under the patronage of the Danish court. Though primarily focused on his instruments, the work also included an appendix on 'architectonic structures suitable for astronomical observations', which offered descriptions and illustrations of his two observatory buildings, as well as a map of Hven based on his own observational data. As such, the <i>Mechanica</i> offered not simply an overview of Tycho's instruments, but rather a presentation of his whole astronomical programme for which he was seeking financial support. This engraved image depicts Tycho's famous mural quadrant, with which he measured stellar altitudes. The arc itself is divided using transversal points ' diagonal lines drawn between consecutive pairs of divisions to artificially extend the distance between points, allowing greater subdivision of the measuring scale. Though this technique was not invented by Tycho, he is particularly credited for its novel application to astronomical instruments, which thus improved the resolving power of his tools. As a result, Tycho was able to claim precision of up to five seconds using this quadrant. Similarly, this instrument made use of Tycho's innovative sighting devices, which consisted of a series of parallel slits through which celestial phenomena could be aligned, removing potential parallax errors inherent in traditional pinhole sights. Besides presenting the mural quadrant itself, this image also offers an idealised representation of life within Tycho's island observatory. The assistants in the foreground offer a sense of the mural quadrant in use, as well as the collaborative nature of Tycho's observational programme. Alongside the assistants, Tycho Brahe himself is also depicted within the arc of the quadrant, seated at a table in his noble attire. Gesturing both to the aperture in the wall through which observations are made and to the open text on the table before him, Tycho emphasises the important role of both theory and observation to his astronomy. In the background, through the architectural frames, one is presented with a view of the different levels of Tycho's observatory building and the respective activities undertaken therein. The lowest level, in the basement, contains Tycho's alchemical laboratory. Though Tycho is renowned for his celestial observations, this image highlights the importance also of alchemical studies, which he describes as his 'terrestrial astronomy'. Above the laboratory is the library, where his various assistants are seen at work. The great brass globe upon which Tycho recorded stellar positions based on his own observational data is prominently positioned in the centre. Above this, on the top level, are his observational decks, where several of his astronomical instruments can be seen. This image thus gives an indication of the scope of instrumentation available to Tycho; from the mural quadrant in the foreground, to the numerous instruments depicted in the background. The small mechanical globe in a niche above Tycho's head also serves to reinforce the multiple functions of astronomical instruments in this period; they could be simultaneously precision observational tools, demonstration models, and elaborate ornaments. The inscription (RS) at the top of the image reads as follows: Figure of Tycho Brahe, son of Otto, the builder of this building and astronomical instruments. In the year 1587, at the age of 40 years.</p>
