Two unsigned Flemish astrolabes
It is still something of a puzzle that many fine early instruments were not signed by their makers, although the more usual practice was to include a signature.
[1] has been attributed to the Antwerp workshop of Michael Coignet, but this is far from certain. [2] has many of the characteristics of instruments produced in the workshop begun in Louvain by Gemma Frisius and directed by Gualterus Arsenius. It may be by a slightly later maker from the same region, perhaps associated with the Louvain workshop at some time in his career, or perhaps simply copying the Arsenius style.