Accession No

0440

Brief Description

gauging slide rule, Everard’s pattern, English 18th C.

Origin

England

Maker

Class

calculating

Earliest Date

1700

Latest Date

1800

Inscription Date

Material

wood (boxwood)

Dimensions

length 629mm; breadth 30mm; thickness 17mm

Special Collection

Robert Whipple collection

Provenance

Purchased from T.H. Court in 05/1927.

Inscription

Description Notes

First face:
log scale divided 1 - 10[0] numbered 1, 2, 3 ... 1[0], 2[0] ... 10[0]; 1 - 2 subdivided to 0.02, 2 - 5 subdivided to 0.05, 5 - 10 subdivided to 1, 10 - 20 subdivided to 0.2, 20 - 50 subdivided to 0.5, 50 - 100 subdivided to 1. This line appears on the stock marked ‘A’ and twice on the slider marked ‘B’ and ‘Num’.
Brass gauge points inlet on scale ‘A’ at ‘MB’ (for malt bushel) and at ‘A’ for (ale gallon); on scale ‘B’ at ‘W’ (wine gallon) and at ‘C’ (3.14 or π).
On the stock a further log scale inverted divided [2.15] - [215] numbered and subdivided as before and marked ‘M*D’ (malt depth).
Verso of slide calibrated with scale of inches divided [25.5] - 49 numbered by 1 subdivided to 0.1 with corresponding calibration [1] - [6.7] numbered by 1G subdivided to 0.05 (for gallons in an inch deep tub of that diameter)

Second face:
on the stock a log scale marked ‘D’ divided 1 - 10 numbered by 1; 1 - 2 subdivided to 0.01, 2 - 3 subdivided to 0.02, 3 - 10 subdivided to 0.05.
Brass gauge points inlet at ‘WG’ (wine gallon), ‘AG’ (ale gallon), ‘MS’ (solid malt bushel), ‘MR’ (round malt bushel).
On the slider scales marked ‘C’ and ‘Num’ identical to scale A on first face.
On the stock scales of segments ‘SL’ (cask lying) and ‘SS’ (cask standing) divided 1 - 100 numbered 1, 2, 3 ... 10, 20, 30 ...100; 1 - 5 subdivided to 0.1, 5 - 10 subdivided to 0.02, 10 - 100 subdivided to 1. verso of slide calibrated with scale of inches divided [48] - 72 and scale of gallons [6.4] - 14G calibrated as before.

First side:
scale of inches divided [0] - 24 numbered by 1 subdivided to 0.1.
Scale of ‘spheroid’ divided [0] - [7.5] numbered by 1 subdivided to 0.1
Scale of ‘2d variety’ divided [0] - [6.5] numbered by 1 subdivided to 0.1
Scale of ‘3d variety’ divided [0] - [5.5] numbered by 1 subdivided to 0.1

Second side:
scale of equal parts divided [0] - 100 numbered by 10 subdivided to 1
scale of inches divided [0] - 24 numbered by 1 subdivided to 0.1
scale for 4th cask variety (?) divided [0] - 6 numbered by 1 subdivided to 0.1

Condition good; 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:39552