There is very little record of world famous Irish Victorian telescope maker Thomas Grubb's idiosyncratic, but magnificent sector microscope, patented in 1854. Very few were made, but there are examples at the Science Museum London, The Oxford Museum of Science and the Macleay Museum in Australia.
Grubb's intention was to provide radial illumination at wide ranging angles by the application of a lenticular prism in a grooved sector. The unique stage mechanics operate by the rotation of two circular plates and the fine focus is controlled by a knob on a lever mounted behind a mahogany cover at the rear of the microscope.
Certainly the most distinctive and remarkable microscope I have seen, it comes with its original case and accompanying slide cabinet.