Accession No

0073


Brief Description

5 gauging slide rules, 19th C


Origin

England (?)


Maker


Class

calculating


Earliest Date

1800


Latest Date

1900


Inscription Date


Material

wood; metal (brass)


Dimensions

all rules approximately length 325mm; width 45mm


Special Collection

Robert Whipple collection


Provenance

Hutchinson Collection


Inscription


Description Notes

Each rule made of wood with central slide and ends bound in brass.
0073.1 one side: upper part of stock has scale ‘per cent under proof’ divided [41] - [88], numbered by 5, subdivided to 1. Slide has one scale starting on upper edge and continued on lower, divided 80 - 95 and 95 - 99, numbered by 1. Lower part of stock has scale ‘per cent under proof’ divided 88 - 99, numbered by 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1.
Other side: very worn. Upper part of stock has scale which is per cent over and under proof, divided 50 - P [0] - 30, numbered by 5, subdivided to 1. Slide has single scale in two parts divided 0 - [43] and [34] - [81], numbered by 5, subdivided to 1. Lower part of stock has scale of ‘per cent over proof’ divided [25] - [69], numbered by 5, subdivided to 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1. Paper stuck to scales has obscured parts of them.
0073.2 one side: upper part of stock has scale ‘per cent below R’ divided [17] - 85, numbered by 5, subdivided to 1. Slide has one scale starting on upper edge and continued on lower, divided 80 - 95 and 95 - 99, numbered by 1. Lower part of stock has scale ‘per cent below R’ divided [81] - [99], numbered by 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1.
Other side: upper part of stock has scale which is per cent below and above R for ‘28 under P’, divided [33] - R [0] - 80, numbered by 5, subdivided to 1. Slide has single scale in two parts divided 0 - [45] and 35 - 80, numbered by 5, subdivided to 1. Lower part of stock has scale of ‘per cent above R’ divided [75] - [135], numbered by 5, subdivided to 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1. Indecipherable MS in ink on lower part of stock.
0073.3 one side: upper part of stock has scale for per cent under and over proof, divided 54 - P [0] - 26, numbered by 2, subdivided to 1. Slide has one scale starting on lower edge and continued on upper, divided 0 - 46 and 40 - 86, numbered by 2, subdivided to 1. Lower part of stock has scale for per cent over proof divided [25] - [69], numbered by 2, subdivided to 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1.
Other side: almost all of scales worn off.
0073.4 one side: upper part of stock has scale ‘per cent below D’ divided [46] - 90, numbered by 5, subdivided to 1. Slide has one scale starting on upper edge and continued on lower, divided 80 - 95 and 94 - 99, numbered by 1, subdivided to 0.5. Lower part of stock has scale ‘per cent below D’ divided 88 - 99, numbered by 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1.
Other side: upper part of stock has scale which is per cent below and above D for ‘8 over proof’, divided [55] - D [0] - 20, numbered by 5, subdivided to 1. Slide has single scale in two parts divided 0 - [45] and [35] - 80, numbered by 5, subdivided to 1. Lower part of stock has scale of ‘per cent above D’ divided [15] - [56], numbered by 5, subdivided to 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1. Indecipherable MS in ink on lower part of stock.
0073.5: one side: upper part of stock has scale ‘per cent under proof’ divided [59] - 93, numbered 60, 62...80, 81, 82...93, subdivided to 1. Slide has one scale starting on upper edge and continued on lower, divided 84 - 97 and 96 - 99, numbered by 1. Lower part of stock has scale ‘per cent under proof’ divided 90 - 99, numbered by 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1.
Other side: upper part of stock has scale which is per cent over and under proof, divided [59] - P [0] - 26, numbered by 2, subdivided to 1. Slide has single scale in two parts divided 0 - 48 and [35] - 86, numbered by 2, subdivided to 1. Lower part of stock has scale of ‘per cent over proof’ divided 24 - 70, numbered by 2, subdivided to 1; also ‘thermometer scale’ divided 30 - 80, numbered by 10, subdivided to 1.

Condition fair (paper stuck to 0073.1 and 0073.3 very worn on one side); complete


References


Events

Description
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.



FM:42243

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