Fame and Legacy: Ramsden “Mementos” from the past 100 Years
Stock Number: (8656)
$350/the group of three
Countries of manufacture
UK and Ireland, North America, Other
Description
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Ramsden’s name continues in current usage, whether as the “Ramsden disk” (the exit pupil of a telescope), the “Ramsden eyepiece” (his design, with twin plano-convex lenses, the curves facing each other), or “Point Ramsden” (in present day British Columbia, named by Captain Vancouver on his 1793 explorations). Even a lunar crater bears his name, located at lunar latitude -32.9°, longitude -31.8° And much of his instrumentation has had a long productive life: his (or Troughton’s version of his) dividing engine in the Science Museum was put into service in World War II in the division of scales on sextants (see Calvert). Here we present a group of rather modern objects which carry on his name. |
–ADVERTISING CARD FOR BEEF EXTRACT, English for the French market, c. 1910, signed “Bouillon Oxo de la Comp’ie. Liebig.” This 2-7/8″ x 4-3/8″ (7 x 11 cm) color lithographed card depicts a salon scene (with typically Continental Baroque 18th century furniture) showing Ramsden presenting his electrostatic machine in 1766. A legend credits him with the flat plate design and with improvements in the collectors and conductors. Very fine.
–A PAIR OF MODERN FLAT-FIELD “RAMSDEN” EYEPIECES FOR MICROSCOPES, American, second half 20th c., engraved “6x (and 15x) Ramsden W.F.” (i.e., wide field). Made of plated brass, with coated optics, each eyepiece is the modern standard size of 23 mm (about 7/8″) outside diameter. Giving magnifications of 6 and 15 power respectively, the eyepieces conform to Ramsden’s design giving a flat field with focal point beyond the furthest lens. It is thus a design ideal for use with micrometer or reticle. Very fine throughout.
–EGREGIOUS “FAKE / REPLICA” POCKET SUNDIAL, Indian, early 21st (!) century, signed “Ramsden, London.” Made of bright cast brass, the sundial is constructed (poorly) with a 3″ (7.5 cm) diameter housing, folding gnomon over decorated chapter ring “divided” from 4 am to 8 pm, and suspension ring. The upper assembly is hinged; when tilted up, in a thereby useless position as sundial, it exposes the glazed compass with rose, degree scale, needle, and needle lifter. Condition is new. This is one of the flood of mass market “replicas” coming out of Mumbai (Bombay), here curiously carrying on the Ramsden name!
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Dealer information
TESSERACT
David and Yola Coffeen both have enjoyed academic careers, as planetary astronomer and as linguist/educator. But since 1982 (yes, 1982!) they have been full-time dealers in early scientific and medical instruments, under the name Tesseract. Selling primarily by catalogue (over 100 issued so far) they also have a web presence at www.etesseract.com, and can be contacted at [email protected].
