F.21 Data Sheet MJS-p-0291

Blundell Rules Limited, AL6, 1949-1958

Serial Number or Date Stamp:

Country: UK Primary construction material: pl Case included?: yes

General Description: Advanced linear log-log slide rule

Length of 1 decade = 10 in, and overall scale length = 10 in. The largest physical dimension is 10 in.

Front Scales: in /| UL A [ B R C ] D LL

Back Scales: [ S ST T ] cm

Notes: Pat No 644944; 3-hairline cursor; owner M. Levitt; original hinged box with clasps

References: https://osgalleries.org/makers/reference/blundell1.pdf; https://patents.google.com/patent/GB644944A/en?oq=GB644944

Date Acquired: 02/06/2023