Astronomical Images : Representing arcs

Daniel Santbech

Astronomical Images

<p style='text-align: justify;'>Daniel Santbech's <i>Problemata</i> is a miscellaneous work in mixed mathematics, including astronomy, gnomonics, perspective, surveying, gunnery and navigation. The unifying element in such a wide range of disciplines is the instrument called the geometric quadrant. According to Lynn Thorndike, Santbech showed appreciation both for specific aspects of Copernicus's work, such as lunar theory, and for the <i>Prutenic Tables</i>, but he ignored cosmological issues. Copernicus is mentioned many times. Virtually nothing is known about Santbech, apart from the fact that he published, in addition to this work, an edition of Regiomontanus's <i>De triangulis</i> (Basel, 1561). The title-page calls Santbech '<i>Noviomagus</i>', and this is generally interpreted as meaning 'of Nijmegen', but Andreas Kleinert reports that Santbech could be from Speyer of Neumagen, a small town near Trier. The volume included a dedicatory letter by Santbech to '<i>Domino Joanni Ludovico a Windeck</i>', dated 1561. The existence of a 1542 Basel edition is disputed by Ernst Zinner. The figures in this edition seem to have been copied from Oronce Fine's <i>Protomathesis</i>. This figure appeared in a section on the determination of the latitude and longitude of a planet or comet. It shows two fixed stars and a planet, although in contrast to the previous figure in this section, the planet is also shown as a star. We get a sense from this figure of the sort of three-dimensional thinking that would have been required of readers of works such as this. Here, arc gdh and arc ldk were understood to rise up out of the plane of the paper, intersecting at points o and d. We can imagine that visual conventions such as these would have taken some getting used to.</p>