spring balance DC ammeter
Datecirca 1885
Inventory Number0487
ClassificationAmmeter
Subject
Maker
Friedrich Kohlrausch
1840-1910
User
Department of Physics, Harvard University
founded 1884
Place of Origin
Place of Use
Dimensions52.9 x 17 x 17 cm (20 13/16 x 6 11/16 x 6 11/16 in.)
Material
DescriptionA spring balance D.C. ammeter, consisting of a solenoid coil about 5 1/2" high, which is supported by a tripod stand with 2 leveling screws on each arm. Above the coil is a nickled tube with a spring and an iron armature. On the side of this tube is a 14cm, unnumbered, vertical scale and pointer.
The pointer was pulled down as the current increased.
The name Kohlrausch is engraved above the coil, indicating that this instrument was made by the German physicist Friedrich Kohlrausch (1840-1910), who studied thermal conduction and magnetic and electrical precision measurements. He is remembered in part for his commitment to improving laboratory conditions and instruments to facilitate maximum efficiency and precision.
The pointer was pulled down as the current increased.
The name Kohlrausch is engraved above the coil, indicating that this instrument was made by the German physicist Friedrich Kohlrausch (1840-1910), who studied thermal conduction and magnetic and electrical precision measurements. He is remembered in part for his commitment to improving laboratory conditions and instruments to facilitate maximum efficiency and precision.
Signedengraved above coil: Kohlrausch No 2908
Inscribedunderside of tripod: 1861
FunctionMeasurement of D.C. currents.
ProvenanceFrom Department of Physics, Lyman Laboratory, Harvard University.
Wilhelm Eduard Weber
Date: 1930-1950
Accessories: black wooden frame
Object number: 1998-1-1189
Digital Equipment Corporation
Date: circa 1980
Object number: 1998-1-1042
Leeds & Northrup Company
Date: circa 1950
Object number: 1997-1-1095
Anthoine Mestrel
Date: 1551
Accessories: old velvet pouch
Object number: DW0592
Carl G. Barth
Date: circa 1904
Accessories: storage box
Object number: 1990-5-0020
Carl G. Barth
Date: circa 1904
Accessories: storage box
Object number: 1990-5-0021
Buff & Buff Manufacturing Company
Date: circa 1905
Accessories: wood case; leather case; right-angle prism; plumb bob; oil flask; tripod (5174b)
Object number: 5174a
R. & J. Beck
Date: 1876
Accessories: oculars (2) in microscope; Darker's selenite retarding filters (3); wheel diaphragm; mechanical rotary stage; stage slider. Other accessories are in the case (1122b), including monocular draw tube; oculars (3); objectives in cans (5); empty can; Lieberkühn; polarizing set; slides; camera lucidas (2); etc.; plus a Beck patent substage condenser (1122c); and apertometer (1122d).
Object number: 1122a