Microscope Museum

Collection of antique microscopes and other scientific instruments

Microscope 309 (unassigned maker; Stanhope magnifier; late 19^th century to early 20^th century)

Microscope 309 is known as a Stanhope magnifying glass and should be dated to the late 19^th century or early 20^th century. These types of magnifiers were invented by Charles, the third Earl of Stanhope, and were named after him in the late 1700s. These lenses have a very short focal length. In about 1860, Rene Dagron in France used a modified type of Stanhope lens, differing from the original Stanhope design by a nearly flat surface in one side, whereas the original design featured convex surfaces on both ends (but with different curvatures). These lenses were originally mounted in ivory or bone and became very common (Figure 1).

Figure 1. Stanhope magnifiers sold by several makers and retailers of the 19^th and early 20^th centuries as engraved in the catalogues of the firms: (A) B. Pike (1848 and 1856); (B) R & J. Beck (1930); (C) F Brewer (1910); (D) McAllister (1855, 1867, 1878); (E) NP Lerebours (1846); (F) G Fontaine (1891); (G) Buron (1844); (H) N Boubee (1938); (I) J Queen (1870, 1872); (J) Normand (1880); (L) Negretti & Zambra (1859, 1870s, 1885).