Catalogue Number: 3551 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 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 Engraved Rob Kaye on both faces. 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. This is the same as the base of Cat. No. 2237 How Acquired: Donated by Robert Kaye Date Acquired: 4-3- 2014 Condition: Good Location: Archive office. East wall shelves unit 3. Drawer 10 |