The Orthops slide rule (Instructions for use)
 Catalogue Number: 1940 The Orthops slide rule (Instructions for use) Category: Papers Sub-Category: Ophthalmic product manual/instructions Corporation: Raphael's Ltd Year Of Publication/Manufacture: c 1950 Time Period: 1940 to 1999 Place Of Publication/Manufacture: London Publisher/Manufacturer: Raphael's Ltd Description Of Item: Three fold leaflet giving 6 pages printed in blue ink, 4 figures Historical Significance: This is an instruction manual for the use of the Orthops slide rule originally designed by Englsih optometrist, Lionel Laurance (1856-1936) and developed by Oscar Wood, John Cole and Allan Blackburn. The rule is for face measurements (interpupillary distance, bridge dimensions, length of side, etc) and spectacle frame dimensions. The rule was first designed in the 1920s. The BOA Museum has a similar leaflet dated 1920s by the Museum. This leaflet appears to be a later version. See Cat No 1931 and 1949 for two versions of this rule. How Acquired: Donated by Pamela Sutton, honorary archivist Date Acquired: Aug 2011 Condition: Fair to good Location: Archive office. Pamphlet and ephemera filing cabinet. Drawer 5 |