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Log-Log Duplex Slide Rule

L.E. Jones

A 10″ slide rule made of PVC with grooved rule and ridges on the slide. There are stainless steel stops on both sides. The cursor is of glass with a stainless steel frame and a single cursor line. Scale: Front: L (Mantissa), LL1, DF and CF (folded at pi), CIF, CI, C, D, LL3, LL2. Back: LL0 and LL00 (Reciprocal log-log scales), A, B, T, ST, S, D, DI, K. Includes two small documents. One provides information about the slide rule. The other is an advertisement for Regulux slide rule cleaning paste.

Accession Number: 2010.lej.7

Alternative Name:

Primary Materials: Plastic, Metal, Glass, steel


Old inventory number = 7. At one end, the slide rule is engraved “B. R. L. T.50 Janus Series, Made in England.”

Dimensions (cm):

Height = 1.8, Width = 5.6, Length = 32.7

Function: Facilitating calculations.

Condition: Item is in very good condition.

Associated Instruments:

Manufacturer: Blundell Rules, Ltd., England

Date of Manufacture: c. 1948-1964


Part of the L. E. Jones slide rule collection.

Additional Information and References:

Historical Notes:


  • Donated to UTSIC