Nicolaus Mulerius (1564-1630) was the first professor of mathematics (and medical science)at the newly founded University of Groningen (1614). Until recently very little was known about him. The present book features a facsimile-edition of the auction catalog of his library (1646), a unique copy of which was discovered as part of a bunch of similar catalogs, in 1988, in the rich collections of the Bibliotheca Angelica (Rome). Three of these catalogs -- almost contemporary ones -- are compared with each other. Almost all items in Mulerius' catalog have been identified with the precious help of WorldCat Local: full titles are specified.
Apart from this, two mysterious astronomical instruments of Mulerius, which decorate his formal Academy portrait by an unknown master (1618), have been studied for the first time. One of them appears to be an astronomical ring dial, more specifically a model developed about 1533 by Reinier Gemma Frisius (1508-1555). The other was entirely new in the sense that no similar copy is known. It revealed to be a model of the earth, covered with 5 belts, typical for an earth orbiting around the sun and frozen down at a particular moment, namely the vernal equinox. In both instruments, the place of the city of Groningen at 53 1/4 degree Northern latitude is indicated. Working replicas have been made by Anton Stoelwinder (metallic parts; Gorredijk; cf. www.earlyelectricmotors.nl), Feike Slager (engraving of the scales; Repos Inc., Dokkum; www.repos.nl), Geert Fikkers (wooden parts; Noordelijk Scheepvaartmuseum, Groningen), and Anita Slagter (dustjackets in felt; tailor, Groningen). The nature and working of the instruments were studied together with the staff of the Department of Applied Physics/Materials Science of the University of Groningen, as directed by Jeff Th.M. De Hosson. The book gives a detailed analysis of both instruments.