There is not a lot of information online about Dr. C.E. Bleeker. She was a remarkable woman in dutch history. I found about after rescueing a decade resistor bank from the scrapheap at work. When I googled to find out more I was very surprised.
She was the director and owner of the "Nederlandsche Optiek- en Instrumentenfabriek" in Zeist.
If you have more information to share (for example photo's of products made by the factory etc.), please contact me.
See for photo's and some history: http://stage1.phys.uu.nl/wwwigf/Algemeen/bleeker.html
A dutch text with some history of Zernike and Bleeker:
Update 2010-11: I now found out that most of the links above don't work anymore. Please use Google to search for more info on the web.
Article in the University of Utrecht magazine when a building was renamed into the 'Caroline Bleeker Gebouw'. It used to be called: Fysics workshop. So the building now has a very fitting name !
In the collection of the museum of the University of Utrecht there is a photo of a phase contrast microscope:
See for more info on this kind of microscopes this Wikipedia article.
A very impressive site featuring the work of Tatjana van Vark shows replicas of spectroscopes of Caroline Bleeker. Everyone who appreciates the art of instrumentation building should have a good look at this site !