Scientific Instruments in the Ximenez Household
The Ximenez-da Vega inventory mentions ten scientific instruments, both individually and as sets. They represent fine examples in brass from the best workshop in Antwerp, as well as more common types of instruments in wood. By 1600 the city of Antwerp had become an important center for applied mathematics and the production of scientific instruments. Such objects were probably sought out not solely as useful tools for precision measurement, but also as desirable objects in prestigious collections. The intellectual connotations and historical associations with antiquity contained within these objects reflected on their owners and impressed visitors. Contemporary royal collections, such as that of the Escorial, included many scientific instruments, which were usually located in libraries.
Among the scientific instruments mentioned in the Ximenez inventory are two astrolabes. Astrolabes were among the most intriguing, sophisticated, and attractive historical scientific instruments. Based on a representation of the terrestrial and celestial spheres by means of a stereographic projection, an astrolabe allowed its users to make all sorts of calculations, usually from observations of the sun or some bright stars. In the Middle Ages and the Renaissance they were popular devices to plot horoscopes. One of the Ximenez examples was an astrolabe made by "Master Coignet": Michiel Coignet, the leading mathematician in Antwerp around 1600, had started making astrolabes around 1572. Coignet was a polymath who would well fit the description of the mathematician-practitioner. Ximenez's inventory also includes two other brass instruments by Coignet: a sundial and a quadrant. Both instruments could tell one the time, but the quadrant was primarily designed to measure heights (for example of stars and buildings) and depths (as of wells). These applications were also possible with a Jacob's staff or baculus Jacobi, one example of which is also mentioned in the Ximenez inventory. Based on the practice of triangulation, this instrument consists of a graduated stick over which a transversal can slide. It was popular with navigators, who used it to calculate their position at sea by means of the position of the stars.
The inventory also includes some "instruments for perspective" and "mathematical instruments." Even if it is not entirely clear what is meant by these phrases, we can assume that they concern drawing instruments, similar to the setup illustrated in the famous Dürer engravings from his Underweysung der Messung of 1525. Mastering the rules of perspective and being able to draw from nature was a popular pastime for the elite.
Van Cleempoel, Koenraad, ed. Instrumentos científicos del siglo XVI: La corte española y la escuela de Lovaina. Madrid: Fundación Carlos de Amberes, 1997.
Meskens, Ad. Practical Mathematics in a Commercial Metropolis: Mathematical Life in Late 16th Century Antwerp. Berlin: Springer, 2013.