COMPOUND MICROSCOPE

'PROFESSIONAL' (substage)

MAKER: BAUSCH & LOMB

c. 1882

The substage focuses by straight rack and pinion and has provision for centering by two knurled knobs(red arrows). The yellow arrow points to the tensioning spring which pushes on a pin which keeps the sleeve taut against the adjustment knobs.

The substage can also be turned completely out of the optical axis via a hinge. The substage sleeve can accomodate multiple accessories. With this outfit is a wheel of apertures. The substage is held locked in its normal axial position by a knurled knob. Once this knob is loosened, the substage housing can be rotated completely out of the optical axis. This is a much sturdier locking mechanism than those on many other microscopes of the time.