Routledge's Engineer Linear Slide Rule
date: label: date made
content: 1824-1862
name: label: maker
content: Aston, T.
notes: label: Description
content: This is a two-foot, two-fold boxwood rule with a brass hinge and endpieces. Half of one side is a slide rule with A and D scales on the base and B and C scales on the slide. As with MA.306697.01, the C scale is the same as the A and B scales (the square of the D scale), instead of the same as the D scale, as on modern Mannheim slide rules. Below the D scale is marked: SQUARE CYLINDER GLOBE (3 times) ROUTLEDGE'S ENGINEER.
label: Description
content: The first three marks form headings for the tables on the other half of this side when the instrument is folded. The tables give conversion factors from the volumes of geometric solids to units of volume, in both the "old" and imperial systems; conversion factors from the volumes of geometric solids to the weights in pounds of various substances; the areas of polygons from 5 to 12 sides; the gauge points of a circle; and gauge points for pumping engines, to find the diameters of steam cylinders that will work pumps of specified diameter at 7 pounds per square inch.
label: Description
content: The other side has a scale of 24 inches along one edge, divided to sixteenths of an inch for 9 inches and to eighths of an inch for the rest of the scale. There are also scales for making scale drawings that are 1, 3/4, 1/2, and 1/4 inches to the foot. This side is marked: T. ASTON THE ORIGINAL MAKER WARRANTED. One outside edge has scales for 10 and 12 parts to the inch; the other outside edge divides one foot into 100 parts.
label: Description
content: This form of slide rule was invented by Joshua Routledge, a seller of iron goods, in 1808 or 1809. He discussed it in the 1813 (4th) edition of <i>Instructions for the Engineer's Improved Sliding Rule</i>. According to Gloria Clifton, there were two rule makers named Thomas Aston, presumably a father and son, who were in business at various addresses in Birmingham, England, from 1818 to 1862. The references to pre-imperial system units of measure suggest the rule might have been made shortly after the imperial system was adopted in 1824. This instrument was found in the home of Grace Speer, granddaughter of Alfred Speer (1823–1910), an inventor and wine merchant in Passaic, N.J.
label: Description
content: References: John V. Knott, "Joshua Routledge 177[3]–1829," <i>Journal of the Oughtred Society</i> 4, no. 2 (1995): 25; Philip E. Stanley, "Carpenters' and Engineers' Slide Rules: Routledges' Rule," <i>Chronicle of the Early American Industries Association</i> 37, no. 2 (1984): 25–27; Gloria Clifton, <i>Directory of British Scientific Instrument Makers</i> (London: National Maritime Museum, 1995), 11–12; accession file.
label: Location
content: Currently not on view
place: label: place made
content: United Kingdom: England, Birmingham, Birmingham
topic: label: Subject
content: Mathematics
label: Subject
content: Rule, Calculating
label: Subject
content: Engineering, General
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Slide Rules
creditLine: label: Credit Line
content: Gift of Leila D. Lovelace
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1981.0934.01
label: catalog number
content: 1981.0934.01
label: accession number
content: 1981.0934
objectType: label: Object Name
content: calculating rule
label: Object Name
content: slide rule
physicalDescription: label: Physical Description
content: boxwood (overall material)
label: Physical Description
content: brass (part material)
label: Measurements
content: overall: .3 cm x 31.6 cm x 4.5 cm; 1/8 in x 12 7/16 in x 1 25/32 in