cathetometer
Date1870-1890
Inventory Number1998-1-0249
ClassificationCathetometer
Subject
Maker
William Grunow
fl. 1849 - 1890
Cultural Region
Place of Origin
Dimensions53.4 x 28.7 x 28.7 cm (21 x 11 5/16 x 11 5/16 in.)
Material
DescriptionThe instrument rests on three feet, each of which has a leveling screw. The pillar rotates and can be finely adjusted by two tangent screws. There is no vernier or scale for that purpose.
A graduated silver line runs along the pillar. The scale is in centimeters, from -1 to 51, divided in millimeters. A vernier is attached to the bracket supporting the telescope. On the left, a rotating magnifying lens was added to better see the vernier's scale. A screw is used for fine height adjustments.
The telescope is held in place by a brace fixed to the mount. Two screws, at each end of the telescope, are used to focus the eyepiece and objective. A tangent screw at the top is used to precisely adjust the vertical inclination of the telescope. A counter weight is attached to a sliding support at the back.
A graduated silver line runs along the pillar. The scale is in centimeters, from -1 to 51, divided in millimeters. A vernier is attached to the bracket supporting the telescope. On the left, a rotating magnifying lens was added to better see the vernier's scale. A screw is used for fine height adjustments.
The telescope is held in place by a brace fixed to the mount. Two screws, at each end of the telescope, are used to focus the eyepiece and objective. A tangent screw at the top is used to precisely adjust the vertical inclination of the telescope. A counter weight is attached to a sliding support at the back.
Signedunder telescope: W'M Grunow / New York
FunctionA cathetometer is an instrument used for the accurate measurement of differences of heights. Large cathetometers could measure differences of as much as one meter. It was used, for instance, to determine the precise differences in the height of a column of mercury at different times during an experiment involving barometric measurements. In chemistry, it could accurately measure the difference of height of two liquids in glass vessels.
ProvenanceTransferred to CHSI from the Department of Engineering, Pierce Hall, Harvard University, via Richard Land, November 25, 1987.
Société Genevoise pour la Construction d'Instruments de Physique et de Mécanique
Date: 1880-1890
Accessories: Check see also records: box of weights and other parts (#1998-1-0248c); extra mount for finderscope (#1998-1-0248b).
Object number: 1998-1-0248a
Legey
Date: circa 1838
Accessories: shades with double tabs (4); shades with single tab (4); screwdriver and square key.
Object number: 5268
Société Genevoise pour la Construction d'Instruments de Physique et de Mécanique
Date: 1880-1890
Object number: 1998-1-0248c
Johann August Oertling
Date: circa 1860
Accessories: box of crystal holders (2007b)
Object number: 2007a
Johann August Oertling
Date: circa 1860
Object number: 2002
William Cary
Date: 1789-1825
Accessories: small eyepiece (box)
Object number: 5230a
Fauth & Company
Date: 1874-1905
Accessories: bubble level
Object number: 1997-1-1808
W. & L. E. Gurley
Date: ca. 1884
Accessories: solar attachment; case; level; green filter; sun shade; tripod (5163b)
Object number: 5163a
John H. Temple
Date: 1850-1870
Accessories: carrying case; dust cap; leather straps; tripod (5166b)
Object number: 5166a