The Museum of the History of Science in Oxford holds a spectacular collection of thousands of early scientific instruments, such as the microscope below. The Museum can be visited on afternoons (except Mondays) for those fortunate enough to be in Oxford, but there is an excellent virtual tour, so that people from around the world can explore what the Museum has to offer. There are also many online exhibits and several YouTube videos. Few museums have an online presence this good. Even the shop is online!
For more information, see the museum website or the Wikipedia article.
Pingback: Data Sculpture | Scientific Gems