Empire datum frame rule

Catalogue Number: 2237
Empire datum frame rule
Category: Equipment
Sub-Category: Dispensing tool
Year Of Publication/Manufacture: c 1950
Time Period: 1940 to 1999
Description Of Item: Datum frame rule, steel, 202 mm x 72 mm, with parallelogram for 'boxing' the spectacle frame to determine the location of its datum with other scales engraved on the base plate to measuring eye size and locating lthe optical centres and bifocal height to be measured in relation to the datum line. Marked EMPIRE DATUM FRAME RULE / COPYRIGHT
Historical Significance: This may have been made by M Wiseman and Company Ltd, a UK optical supply house. The book L S Sasieni Spectacle fitting and optical dispensing 1950 (Cat nos 776 )2243) has an informative chapter (ch 2) on frame rules and one (ch 5) on devices for face measurements.
How Acquired: Donated by Bruce Dudon, spectacle maker, Woodend
Date Acquired: June 2013
Condition: Very good except on pivot not secured
Location: Archive office. East wall shelves unit 3. Drawer 10

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