Exhibition ' Marvellous Invention: Four Hundred Years of Logarithms' (August - October 2014)
Four Hundred Years of Logarithms
This year is the 400th anniversary of John Napier's publication of logarithms. This small display marks the essential role of logarithms in calculation over the succeeding 350 years. It draws on printed numerical tables from the Museum's library collections and also features logarithmic slide rules.
Logarithms had a practical purpose in calculation, but might still be classed as belonging to ‘pure’ mathematics, their physical manifestation a set of printed tables. But renaissance mathematicians were fond of translating their ideas into instruments, as the collections of this museum demonstrate.
Within a few years of Napier’s invention the Oxford mathematician and inventor Edmund Gunter (1581-1626) had introduced a logarithmic scale or ‘line’ to his navigator’s calculating scale. In 1632 the instrument maker Elias Allen made a large circular instrument designed by William Oughtred (1575-1660), called the ‘circles of proportion’ (displayed elsewhere in this museum), which was effectively a circular slide rule. It was also Oughtred who, at the same time, first improvised a linear instrument consisting of two of Gunter’s logarithmic scales sliding together, or with a sliding scale between them.
For 350 years this latter form of slide rule, using logarithms to aid multiplication, division, and certain specialised calculations, was the most typical and essential instrument in mathematical calculation, its users ranging from humble schoolchildren to top engineers. A selection of slide rules dating from 1737 to about 1960 is shown here; others can be seen in the nearby special exhibition ‘Geek is Good’.
Boxwood simple slide rule, in a heavily decorated leather slip-case dated ‘ANO 1737’. Lewis Evans Collection. Inv.no.43974.
Boxwood and ivory six-scale slide rule, including two sliders and inch ruler, marked ‘The Ich Dien Rule’ and ‘Arranged by S. Waddington Barnsley’, 19th century. Lewis Evans Collection. Inv.no.52599.
Boxwood slide rule by ‘Stanley Great Turnstile Holborn London’, standard logarithmic scales on the sliding side and on the back a conversion scale of inches and centimetres devised by E. M. Nelson, 1894. Inv.no.52108.
Two white plastic ‘Aristo Multilog’ slide rules, the common 6-inch and a sophisticated 13-inch, in leather pouch and grey card slip-case respectively, by Dennert & Pape, Hamburg, the large one having an additional separate logarithmic scale dated 1958. Whillock Collection. Part of inv.no.13436.
- Inventory no. 34185 - Former Display Label
- Exhibition 'Marvellous Invention: Four Hundred Years of Logarithms' (August - October 2014) - circular slide rule
- Exhibition 'Marvellous Invention: Four Hundred Years of Logarithms' (August - October 2014) - library collections