Accession No
6288
Brief Description
slide rule and case, model 1/98, for use in electrical calculations, by Faber-Castell, German, c. 1960
Origin
Germany
Maker
Faber-Castell
Class
calculating; mathematics
Earliest Date
1960
Latest Date
1960
Inscription Date
Material
Slide rule: plastic (celluloid?) on wood, metal tongue on slide Cursor: plastic, metal pins/screws Case: card with faux leather finish
Dimensions
Slide rule: 300mm x 38mm x 10mm Case: 240mm x 50mm x 12mm
Special Collection
Provenance
Donated on or before 02/07/2009.
Inscription
Slide rule: Well of stock: A.W. FABER-CASTELL 1/98 ELEKTRO MADE IN GERMANY
on base of stock: Copyright A.W. FABER-CASTELL
STEIN near Nuremberg
Serial no. (?) on base of stock: 7 59
on reverse of slide: CASTELL
Case: FABER-CASTELL 1/98 CASTELL-ELEKTRO
Description Notes
Wooden slide rule with white plastic/celluloid covering, single double sided slide, colourless transparent plastic cursor
Marked with scales as follows:
Obverse of slide:
sin scale (in blue), numbered 40’, 50’, 1°, 2...10, 15, 20, 25, 30, 40...90. On same scale: cos (in red), numbered 89, 88...80, 75, 70, 65, 60, 50, ...20
lg scale, numbered 9, 8...1
tg scale (in blue), numbered 6, 7...20, 25...45. On same scale: ctg (in red), numbered 80...50.
Reverse of slide:
HP [horsepower] scale, numbered 8, 9, 1, 2, 3, π, 4...10, 20...100
Temperature (?) scale, numbered 32°, 59°, 68°, 77°, 122°, 167°
Logarithmic scale, marked 1.1, 1, 9, 8,...4, π, 3, 2, 1.9, 1.8...1.1, 1, 9
Logarithmic scale, marked 9, 1, 1.1, C, 1.2...2, 3, π, C1, 4...10, 1.1, C
Top of stock:
Logarithmic scale numbered 1.1, 1.12, 1.14...1.2, 1.25...1.8, 1.9...3, 3.2
KW [kilowatt] scale numbered 8, 9, 1...3, π, 4....7, 7.45, 8, 9, 10, 20...100 with label ‘10 Amp’
Logarithmic scale numbered 9, 1, 1.1...2, 3, π, W, 4, 5, R, 6...10
Logarithmic scale numbered 2.5, 2.6...3, 3.5...6, 7...10, 15...30, 40, 50, 100, 2...9, 103, 2...5, 104, 2...5, 105
Well of stock:
Dynamo /motor scale numbered 30, 400....100, 90...20
Volt scale numbered 0.6, 0.7...1, 1.5...5, 6...10
Sides of stock:
10-inch ruler
Logarithmic scale numbered 1...10, 20, 100, 200...1000
Cursor: marked with various lines, two labelled kW, two labelled HP
Base of stock: various tables of values including decimal /imperial conversions, values of π, π2, etc, and the weights of various metals, and two diagrams
Both base of stock and case are marked with previous owner’s (donor’s) name, J.P.J. van Vuren
Case is missing lid.
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.
This particular slide rule was designed for use in electrical calculations.
FM:46770
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