Microscope Museum

Collection of antique microscopes and other scientific instruments

Microscope 315 (unassigned maker; Coddington magnifier; late 19th century to early 20th century)

Microscope 315 is known as a Coddington magnifying glass and should be dated to the late 19^th century or early 20^th century. Coddington magnifiers consist of a single very thick lens with a central deep groove diaphragm at the equator, thus limiting the rays to those close to the axis, which minimizes spherical aberration. These lenses were very common, are still available today, and were used in the field by botanists and naturalists due to its small size, good magnification, and portability (Figure 1). The first version of these types of lenses was introduced by William Hyde Wollaston in 1812, who used two hemispheres of glass mounted together with a small stop between them. David Brewster improved the design of these lenses by using a single piece of glass and cutting a deep groove in it. In 1829, Henry Coddington popularized the Wollaston-Brewster lens, and further refined their design by modifying the shape of the groove.

Figure 1. Coddington 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) E. Vion (1929); (B) Townson & Mercer (1894); (C, D) Ernest Goldbacher (1879); (E, F) B. Kahn & Son (c. 1890); (G) Arthur Chevalier (1869); (H) Bausch & Lomb (1899); (I, J, K) B. Pike (c1890); (L) P Rousseau (1888); (M) Miller Bros (1879); (N) Prolabo (1932); (O) J. Queen (1870; 1872; 1883; 1890); (P) Normand (1880); (Q) (E. Deyrolle (1931); (R) N Boubee (1938); (S) F Brewer (1910); (T, U) R & J Beck (1882); (V) J. Queen (1870; 1872); (X) J. Queen (1870; 1872; 1883; 1890).