Holometer of Brunel
date: label: date made
content: ca 1830
name: label: maker
content: Brunel de Varennes, Louis-Clement
notes: label: Description
content: This instrument has a black wooden case painted to resemble a book. On the inside is a paper scale in the shape of an octant (eighth of a circle), screwed to the case, with the center of the circle at the front left corner. A metal arm that pivots on this center has a plastic indicator at the opposite end. Scales lettered from A to N that are marked near the circumference. The scales represent tangents, cotangents, sines, cosines, the division of an arc of a circle into differing numbers of equal parts, lengths of the sides and areas of inscribed polygons, areas of the faces and volumes of inscribed polyhedra, and proportions of ellipses. Across the bottom edge are two linear scales, one of centimeters divided to millimeters and one of inches divided to lines (twelve lines/inch).
label: Description
content: The holometer was an invention of the French nobleman Louis-Clément de Brunel de Varennes who spent many of his formative years fighting Napoleon’s army. The engraving of the scales was done by Pelicier. Brunel envisioned the instrument as a replacement for the sector, particularly useful in design.
label: Description
content: The instrument was noted in contemporary journals but does not seem to have become common.
label: Description
content: References:
label: Description
content: L.-C. Brunel de Varennes, <I>Métroscopographie, ou Nouveau système de perspective</I>, Paris: Bachelier, 1830.
label: Description
content: J. W. Woollgar, “Description of the Holometer,” <I>Mechanics Magazine</I>, vol. 14, September 18, 1830, pp. 40-42.
label: Location
content: Currently not on view
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Trigonometry
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content: Science & Mathematics
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1987.0606.02
label: accession number
content: 1987.0606
label: catalog number
content: 1987.0606.02
objectType: label: Object Name
content: Calculating Instrument, Trigonometric
physicalDescription: label: Physical Description
content: wood (case material)
label: Physical Description
content: paper (scale material)
label: Physical Description
content: metal (arm material)
label: Physical Description
content: plastic (indicator material)
label: Measurements
content: overall: 3.6 cm x 45.6 cm x 33.2 cm; 1 13/32 in x 17 15/16 in x 13 1/16 in