string galvanometer
Date1900-1915
Inventory Number0240
ClassificationGalvanometer
Subject
Maker
American
?
User
Department of Physics, Harvard University
founded 1884
Cultural Region
Place of Use
Dimensions34.3 × 18.4 × 19.2 cm (13 1/2 × 7 1/4 × 7 9/16 in.)
Material
DescriptionGalvanometer with three stacked permanent U-shaped magnets with long coil and string suspension housed inside brass suspension tube. Removable glass plate fits over poles of magnets. Brass base with three curved legs and three leveling screws. Two binding posts mounted on sides of front two legs with center grounding terminal. Similar to object 0489.
Signedunsigned
FunctionThis instrument was most likely used as a string galvanometer per se, for physics experiments, not as an electrocardiograph. The basic principle of this instrument is opposite of a common galvanometer. Instead of having a current pass through a stationary coil, creating a magnetic field which will then act on a movable magnet, this instrument is made of a stationary magnet between which an electric current to be determined passes through a fine wire. For more information on this type of instrument, go to the following website.
String galvanometers were essential to early electrocardiograph. For an image of such a set-up, go to the following website.
String galvanometers were essential to early electrocardiograph. For an image of such a set-up, go to the following website.
ProvenanceFrom the Department of Physics, Harvard University, 11/21/1956.
American
Date: 1890-1930
Object number: 0155a,b,c,d
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
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
American
Date: circa 1915
Accessories: Extra 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.
Object number: 0154a,b,c
L. E. Knott Apparatus Company
Date: 1910-1930
Accessories: bell jar
Object number: 0189a,b