Accession No


Brief Description

slide rule, Jos Suxspeach’s ‘Catholic Organon’ or ‘Universal sliding foot rule’, by Benjamin Parker, English, 1753.




Parker. Benjamin



Earliest Date

Jan. 1, 1753

Latest Date

Dec. 31, 1753

Inscription Date


wood (boxwood); metal (brass)


length 319mm; breadth 30mm; thickness 19mm

Special Collection


Purchased from L.A. Spitz, 561 Kings Road, London, SW6 in 11/1967.


‘* Ios Suxspeach Invr. Ratcliff 19th February 1753 Ben Parker Fecit’ (face A)

Description Notes

Slide rule, Jos Suxspeach’s ‘Catholic Organon’ or ‘Universal sliding foot rule’, by Benjamin Parker, English, 1753.

Boxwood slide rule bound in brass with octagonal slide. Slide has brass bound ends and is hollow to hold a telescope (all telescope parts missing).

All lines on the rule are numbered and titled; the numbers correspond to those given in the book by Suxspeach, which explains the use of the instrument. The two edges have separate slides (with brass central sections to fit into sliding grooves), and there are lines on the undersides of the slides and in the cavity. Also lines in the central cavity. These cavity lines are formulae and tables. Within the edge slides are brass tongues calibrated for use as quadrants.

Incomplete; missing telescope parts.


Mikey McGovern; 'A 'universal' slide rule? John Suxspeach's 'Catholic organon''; Explore Whipple Collections online article; Whipple Museum of the History of Science; University of Cambridge:


Developed during the seventeenth century (c. 1630), the modern slide rule is based upon the design by William Oughtred (1574–1660). The slide rule is one of many calculation devices that operates on the logarithmic scale, a calculation method invented in 1614 by John Napier (1550–1617). Although there are many different types of slide rule and many complicated calculations that can be performed on them, the most common usage involves moving two opposing identical scales so that the required sum is shown, with the answer displayed on the scale.

The Suxpeach slide rule was an expensive object rendering it prohibitive for purchase except by gentlemen of leisure. Suxpeach’s slide rule incorporated expensive optical and navigational instrumentation: a telescope, a plumb-bob and a rectangular quadrant. Unfortunately, this example was an inaccurate instrument for precision measurement. The design allowed for an error of 5, thus is was unsuitable as a navigational instrument.

Created by: Allison Ksiazkiewicz on 08/07/2014


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