any ideas? Microtiome?
Posted 12 May 2021 - 05:27 AM
Description Of Item: Focimeter (syn vertometer, lensometer, lensmeter) for measurement of ophthalmic lens powers and marking-up the centre and axis of ophthalmic lenses, black metal, round base with felt under, adjustable ledge to locate lens or spectacles, retractable spring loaded clamp to hold lens in place, swing out lens marker with three pens and ink pad located on eyepiece arm, adjustable focus eyepiece, right and left knobs on common spindle for focussing to determine lens meridional power, milled ring below eye piece for rotating meridional axis. Scales are internal and viewed through eye piece. 290 mm high. Marked 'ZEISS/WINKEL/960038' Modern electric cord and plug (removed for gallery dispay, stored in Archive Room West Wall Unit1 Drawer 5).
Historical Significance: The principle of the optical design of an instrument for measuring lens power was established by Snellen in 1876 but he used it as a phakometer. Troppmann introduced the first focimeter in 1912 in which dioptric power could be read off a scale. Previously opticians had used the lens curvature measure (spherometer) and lens neutralisation using lenses from a trial case. Carl Zeiss produced its first focimeter in 1915. This vertometer is marked Zeiss/Winkel. Rudolph Winkel was a contemporary of Carl Zeiss in the field of microscopes. He manufactured fine microscopes from 1857 in Gottingen and was succeeded by his sons. Carl Zeiss Optische Werkstatte took an interest in the business and acquired majority ownership in 1911. The makers mark of Winkel instruments changed from 'R. Winkel GmbH' to 'Winkel-Zeiss / Gottingen" in 1928 and became "Zeiss / Winkel" in 1954. This dates this instrument to after 1954 and it was in common use in Melbourne in the mid-1950s.