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Blundell Harling 802 Log-Log Slide Rule

Blundell Harling 802 Log Log slide rule, simplex open frame, plastic with plastic cursor, dating from the 1970s. Scales are K, LL2, LL3, A{B,L,C1,C}D, S, T, ST. Complete with blue plastic case and instructions.

A slide rule is a mechanical analogue computer which was one of the primary methods of calculation up until the mid-20th Century with the introduction of the desktop calculator and electronic computers. They were used for calculations including multiplication and division, as well as functions such as exponents, roots, logarithms, and trigonometry.

Blundell Rules Ltd started making slide rules in about 1947 in Luton. In 1956 they moved to Weymouth. They merged with W.H. Harling of London, who were established drawing instrument makers, to form Blundell Harling Ltd, and moved the Harling business to Weymouth in 1964. They are still in business today in Weymouth, although they no longer make general purpose slide rules.

Manufacturer: Blundell Harling
Date: 1970

This exhibit has a reference ID of CH876. Please quote this reference ID in any communication with the Centre for Computing History.


Blundell Harling 802 Log-Log Slide Rule

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