Websters’ Instrument Makers Database
This database of instrument makers, or more precisely of their signatures, is a product of many years of research by Roderick and Marjorie Webster, longtime curators of the collection of scientific instruments at Chicago’s Adler Planetarium & Astronomy Museum.

Scientific Instrument Makers in the Netherlands
This website provides biographical data about instrument makers who were active in the Netherlands (data largely based on a card index used at Museum Boerhaave).