Motor; Electromagnetic Devices; Magnetic Devices; Electromagnetic Devices
Place made:
United States: Vermont
Date made:
c1837
Date made:
ca 1837
Associated date:
1837
Description (Brief):
No extant maker's markings. A small electric "locomotive" mounted on a circular railway track. The motor consists of two electromagnets, one forming a stationary field and the other an armature revolving in a horizontal plane. The armature is connected with the driving wheels by a speed-reducing bevel gear. The armature and field magnets are each 5 1/2" long with 3/4" diameter cores. They are each wound with two No. 16 copper wires connected in parallel, there being 24 turns of each wire on each core. This specimen is an early example of a shunt-wound motor. The commutator is a split ring with two springs rubbing on the segments. Connections with three cup battery are formed by mercury cups. Coils are painted red, frame is yellow.
F. L. Pope, in his sketch of electric motor development states that a locomotive model was constructed by Thomas Davenport and Ransom Cook in the winter of 1836-37. Presumably, this specimen is that model. The Electrical Engineer's exhibit label states: "This Example, presented by Lewis E. Gurley, Esq., of Troy, N. Y., to Geo. M. Phelps, was made about 1837. Its existence has been traced prior to 1840, when it formed part of the Natural Philosophy Apparatus at Mrs. Emma Willard's Female Seminary in Troy, N. Y."
References: Franklin L. Pope, "The Inventors of the Electric Motor With Special Reference to the Work of Thomas Davenport, Electrical Engineer, 21 January 1891: 65-68; 4 February 1891: 129. Public Ledger, Philadelphia, 4 May 1837. Article on Electro-Magnetism and the work of Davenport. Exhibit label used by donor for an exhibit in 1890's. W. R. Davenport, Biography of Thomas Davenport (1929) Chapter XI.
Location:
Currently not on view
Credit Line:
From American Institute of Electrical Engineers / Institute of Electrical and Electronics Engineers
