Catalogue Number: 3948
Carl Zeiss Vertometer
Sub-Category: Vertometer, lensometer, focimeter
Corporation: Carl Zeiss Jena
Year Of Publication/Manufacture: Pre 1945
Time Period: 1940 to 1999
Place Of Publication/Manufacture: Jena, Germany
Publisher/Manufacturer: Carl Zeiss Jena
Description Of Item: Focimeter (syn vertometer, lensometer, lensmeter) for measurement of ophthalmic lens powers and marking-up the centre and axis of ophthalmic lenses, 280 mm high x 220 mm deep x 150 mm wide. Black painted metal, round base with felt under, adjustable ledge to locate lens or spectacles (38 mm to 60 mm diameter lens), clamp to hold lens in place with two retractable prongs, swing out lens marker with three pens and ink pad located at the front of the lens table, adjustable focus eyepiece, right and left knobs on common spindle for focusing to determine lens meridional power, milled ring below eye piece for rotating meridional axis. Scales are viewed through a separate window behind eye piece. Power switch on lamp housing. Marked 'CARL ZEISS/JENA/6535' Electric cord and plug removed.
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. The lack of 'Winkel' on the marking suggests that this item is pre-World War II.
How Acquired: Donated by Dr. Christopher Buckley, Ophthalmologist
Date Acquired: 16/06/2020
Location: Archive office. East wall shelves unit 3