The main focus utilized
with this microscope operates on the stage by rack
and pinion. The tube remains stationary and has a
fine adjustment operated by the milled knob attached
to the tube which moves the nosepiece. The microscope
is designed to pivot upon its pillar. Another
microscope by the same makers with a similar
focusing arrangement can be found elsewhere on this
The firm was
established around 1840 by the purchase of the
instrument business of Edward Palmer, London.
Instruments by this firm had the signature Horne,
Thornthwaite, & Wood, London from c. 1840-1860
after which, the instruments were signed
Horne & Thornthwaite, London (c. 1860-1880). By
1886 Wood rejoined the firm.