COMPOUND MONOCULAR MICROSCOPE
RETAILER: DOLLLOND
MAKER (ATTRIB):HUGH POWELL
c. 1840
SIGNED: 'DOLLOND, LONDON'
COLLECTION OF: Dr Jurriaan de Groot
The coarse focus is operated by two knurled heads working through a pinion carried within a slider attached to the body tube, the mechanism being internally sprung by a roller bearing from the other side to eliminate any forward and backward slack and also sprung by a piece of bent brass from the right side internally to prevent right-left slack. The rack is embedded into the upper part of the front of the limb.