Ringmicrometer Fraunhofer 3D on Flickr.
museum Boerhaave Leiden meter 1885
Museum Boerhaave is the National Museum of the History of Science and Medicine
As the national treasury of scientific endeavours, the museum shows some 400 years of advances in knowledge. Developments in the various sciences can be viewed in 24 rooms on two levels. The emphasis is on contributions from the Netherlands.