This large microscope has a typical bar-limb construction with rack and pinion focusing. It is based on a design introduced by Andrew Ross introduced in 1843. It measures 20-inches tall inclined as shown in the photos. The rack and pinion focusing sub-stage has centering adjustments. Among the remaining accessories are three objectives (1, 1 1/2, and 1/4-inch) with canisters, a Lieberkuhn reflector for the 1-inch objective with canister, two eyepieces, a stage forceps, a live-box, and a hand forceps.

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.

See a more complete history of the firm here and here.