Accession No


Brief Description

Standard Mannheim-type slide rule, ‘Medaille D’Or 1878’, by Tavernier-Gravet, French, 1878-1889.


Rue Mayet, 19, Paris, France





Earliest Date

Jan. 1, 1878

Latest Date

Dec. 31, 1889

Inscription Date




260mm long x 28mm wide x 9mm deep

Special Collection


Donated by an individual, 02/01/2012.


[On front, below scales] “TAVERNIER-GRAVET RUE MAYET 19 PARIS”
[On reverse, below data table] “MEDAILLE D’OR 1878”

Description Notes

Standard Mannheim-type slide rule, ‘Medaille D’Or 1878’, by Tavernier-Gravet, French, 1878-1889.

Generic calculation slide rule in wood, with wooden slider and brass chisel-point cursor. 25cm-long measuring scale along front edge, and 26cm-long scale along full length of back edge. Slide scales are A, DF [ CF, CI, C ] D, with [S L T] scales on back of reversible slider.

On reverse of rule is a printed table of data, including values for universal standards and conversion ratios.

[Inscribed on front, below scales] “TAVERNIER-GRAVET RUE MAYET 19 PARIS”
[Inscribed on reverse, below data table] “MEDAILLE D’OR 1878”

Condition: fair / complete. Some verdigris on the brass slider. Many dents, marks and scratches to the wood. Small paint contamination on reverse data table.


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, the modern slide rule is based upon the design by William Oughtred (circa 1630). It is one of many calculation devices that is based on the logarithmic scale, a calculation method invented in 1614 by John Napier.

Before the rise of the pocket electronic calculator in the 1970s, the slide rule was the most common tool for calculation used in science and engineering. It was used for multiplication and division, and in some cases also for ‘scientific’ functions like trigonometry, roots and logs, but not usually for addition and subtraction.

A logarithm transforms the operations of multiplication and division to addition and subtraction according to the rules log(xy) = log(x) + log(y) and log(x/y) = log(x) - log(y). The slide rule places movable logarithmic scales side by side so that the logarithms of two numbers can be easily added or subtracted from one another. This much simplifies the alternative process of looking up logs in a table, thus greatly simplifying otherwise challenging multiplications and divisions. To multiply, for example, you place the start of the second scale at the log of the first number you are multiplying, then find the log of the second number you are multiplying on the second scale, and see what number it is next to on the first scale.


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