John Davis (1811-1873)
was a member of a family of Jewish descent long
involved in instrument making, originally in Leeds.
John began to work on his own where he set
up in business in Derby c. 1831 moving to
22 Iron Gate in 1835, where the firm remained until
1865 when they moved to a new premises nearby in Amen
Alley. Davis`s early products were what would be
expected from an optician of the period, but by the
1840s he began to specialize in mining, surveying,
and other industrial instruments in which the company
still produces. Microscopes by the firm are uncommon.
This bar-limb microscope is based on a design
introduced by Andrew Ross.
See a more complete history of the firm here and here.