reflecting galvanometer with moving magnets
Datecirca 1915
Inventory Number0154a,b,c
ClassificationReflecting Galvanometer
Subject
Maker
American
?
User
Department of Physics, Harvard University
founded 1884
Cultural Region
Place of Use
Dimensions51.1 x 20.4 x 18 cm (20 1/8 x 8 1/16 x 7 1/16 in.)
Material
AccessoriesExtra case of coils and extra set of magnets (0154d). Three extra magnets (3 bar magnets and 2 bar magnets attached to an aluminum wire) are not numbered because of size.
DescriptionGalvanometer with two pairs of permanent coils in rectangular wooden case with suspension (missing) for moving bar magnets. Suspension thread supported on two brass rods. Blackened brass cylindrical case (0154b) with suspension tube (0154a) and oval viewing window fits over wooden case. Eight binding posts on bakelite platform extending from base. Extra case of coils (0154c) and extra set of magnets. Similar to object 0153a-d.
Signedunsigned
FunctionReflecting galvanometers are used to measure very small electrical currents and voltage differences. Instead of having a scale with a pointer, in these galvanometers a small mirror turns in the presence of electrical currents. A coil of fine wire hangs between the poles of a magnet that generates a strong magnetic field. When an electric current is sent through the wires of the coil, the coil and the mirror attached to it are deflected. The change of angle can be detected by shining a light at the mirror and observing the reflection on a scale placed in front of the meter.
ProvenanceFrom the Department of Physics, Harvard University, 11/6/1956.
American
Date: 1890-1930
Accessories: extra set of coils without multi-tap windings (0156d, e); extra magnet; square wooden case
Object number: 0156a-f
Department of Physics, Harvard University
Date: 1890-1930
Accessories: extra set of coils without multi-tap windings (0156d, e); extra magnet; square wooden case
Object number: 0156a
Arnheiter
Date: 1830-1840
Accessories: magnets (2); wooden handle with hook; case
Object number: DW0899
Department of Physics, Harvard University
Date: 1890-1930
Accessories: extra set of coils without multi-tap windings (0156d, e); extra magnet; square wooden case
Object number: 0156b
Zeiss-Aerotopograph
Date: circa 1950
Accessories: instrument is in original wood storage/carrying case. listed accessories: base plate, mirrors (2) and tubular holders (2), anchors (2), prism yoke, monocular adapter, lighting set with bulbs (3, one currently in lamp, its box in box of 2009-1-0002b), 2 monoculars (4 or 6 power) [6x24 (infinite) L or R Zeiss aerotopo logo), "fork"-shaped support (V rather), green filters (2) , dioptre lenses (2), strabismus-correcting lenses (2), photo holder, permanent magnets (8)
Object number: 2009-1-0002a
Edward Mills Purcell
Date: 1947
Accessories: Various pieces of apparatus separately cataloged as 2004-1-0408a-g through 2004-1-0416 were used with this magnet in different configurations for different experiments. The fairly large amount of documentation which accompanied this accession -- including student lab reports, bench notes, reprints, wiring diagrams, and other documents -- has been filed under 2004-1-0407.
Object number: 2004-1-0407
Elliott Brothers
Date: circa 1930
Object number: 0232
American
Date: 1890-1930
Object number: 0155a,b,c,d
Siemens, Halske & Company
Date: 1858-1865
Object number: 0179a
Siemens, Halske & Company
Date: 1858-1865
Object number: 0179b
See also/See also
