Beschreibung:

A very rare English compound microscope, unsigned , datable to circa 1680, in lignum vitae, tooled leather, vellum and brass -- 9in. (23cm.) high when in use (average) ; the body tube -- 2 3/8in. (6cm.) diameter ; the base -- 2¾in. (7cm.) diameter The optical tube is in two sections, both the outer and inner are made of pasteboard covered with deep-red morocco leather on the outer, and white vellum on the inner; this has a printed page from a religious tract stuck to the inside. The outer is decorated in three panels by gold tooling, now very dark. A long, threaded brass nose-piece screws into a brass ring at the top of a tripod with straight brass legs. The 2¼in. (5.5cm.) long nose-piece has a small 3/8in. (0.9cm.) diameter plano-convex objective lens ( possibly a replacement ) in a push-on brass cell with a 3mm aperture, and at the top of the inner tube is the 1 3/16in. (3cm.) diameter field lens, also biconvex, and with a few air bubbles, as generally found at this period. The eyepiece mount contains the 11/16in. (1.8cm.) diameter biconvex eye lens that is held in place by a brass split ring. The dust cap is missing. The tooled motifs are nos 7, 13, 67, 68, 69, roll 1, which are illustrated in G. L'E. Turner, Essays , chap.4 "Decorative Tooling on 17th and 18th Century Microscopes and Telescopes" (no.60m). It is shown that these fall into the period 1660-1700, and are often to be found on optical instruments by John Yarwell (1648-1712). However, this small microscope may have come from the workshop of John Marshall (1663-1725), who had a 'trade war' with Yarwell ( see Bryden and Simms, cited below ). A similar, but larger, microscope in the Museum of the History of Science, Oxford, is illustrated in G. L'E. Turner, Collecting Microscopes , p.38. The same pattern is pictured on Yarwell's trade card dated 1683 at the Whipple Museum of the History of Science, Cambridge (op. cit., p.39). At the Science Museum, London, is a closely similar small microscope bearing a few stamps of similar design, but it is not signed (1954-290). See Colour Illustration and Details