flat spiral (or ribbon) coil
Date: 1842-1855
Inventory Number: 0102
Classification: Induction Coil
Attributed to: Daniel Davis, Jr. (1813 - 1887)
Cultural Region:
Place of Origin:
Dimensions:
5.4 × 25 × 22.6 cm (2 1/8 × 9 13/16 × 8 7/8 in.)
Bibliography:
Davis's Manual of Magnetism
Davis's Manual of Magnetism
A Manual of Magnetism
Catalogue of apparatus to illustrate magnetism, galvanism, electrodynamics, electromagnetism, magneto-electricity, and thermo-electricity, manufactured and sold by Daniel Davis, magnetical instrument maker
Daniel Davis, Jr. and the Elecromagnetic Instrument Industry: A Field with Great Potential in the Early 19th Century
DescriptionA one-inch wide strip of copper ribbon is wound into a spiral, making a flat surface, with painted fabric intervening each winding. Two brass binding posts make battery connection with the inner and outer end of the long strip.
This is how Davis described this instrument in his 1842 book on magnetism: "The copper ribbon may be an inch wide and one hundred feet long, the strips being cut from a sheet, and soldered together. Being then wound with strips of thin cotton, it is coiled upon itsef, like the mainspring of a watch; in[s]tead of covering it with cotton, it may be coiled with a strip either of cotton or list intervening. Two binding screw cups are soldered to the ends of the ribbon; the internal end, for convenience, is brought from the centre, underneath the spiral, to its outside, care being taken to insure insulation where it passes the coils. The whole may be firmly cemented together, if desired, by a solution of shellac in alcohol." (pp. 73-74)
The device was sold by Davis $0.75 to $1.00 per pound in 1848.
This is how Davis described this instrument in his 1842 book on magnetism: "The copper ribbon may be an inch wide and one hundred feet long, the strips being cut from a sheet, and soldered together. Being then wound with strips of thin cotton, it is coiled upon itsef, like the mainspring of a watch; in[s]tead of covering it with cotton, it may be coiled with a strip either of cotton or list intervening. Two binding screw cups are soldered to the ends of the ribbon; the internal end, for convenience, is brought from the centre, underneath the spiral, to its outside, care being taken to insure insulation where it passes the coils. The whole may be firmly cemented together, if desired, by a solution of shellac in alcohol." (pp. 73-74)
The device was sold by Davis $0.75 to $1.00 per pound in 1848.
Signedunsigned
FunctionThe self-induced spark and shock in an electrical circuit is augmented by including a spiraled winding. These spiral coils (see also 0102 and 0103) were used to demonstrate that effect, as well as the induction of third and higher order induced currents, as first demonstrated by Joseph Henry around 1838.
From Davis's description (1842): "The spiral being connected with the battery, its two faces will exhibit strong polarity: a dipping needle placed on any part of its surface or near it will always direct one of its poles towards the centre..." (p.74)
From Davis's description (1842): "The spiral being connected with the battery, its two faces will exhibit strong polarity: a dipping needle placed on any part of its surface or near it will always direct one of its poles towards the centre..." (p.74)
Curatorial RemarksThe flat spiral of copper ribbon was devised by Charles Grafton Page (see American Journal of Science, vol. 31 (1836)), and its applications for inducing "higher order" currents was developed by Joseph Henry (see Transactions of the American Philosophical Society, vol. 6 (1839), 303-337). Davis refers to both Henry and Michael Faraday in his discussion of its uses.
See also 0101 and 0103. Each is a different diameter, but 0101 and 0102 are close enough that they might have been used as a matched set. 0103 might have been used to demonstrate the effect with more windings in the spiral.
See also 0101 and 0103. Each is a different diameter, but 0101 and 0102 are close enough that they might have been used as a matched set. 0103 might have been used to demonstrate the effect with more windings in the spiral.
Primary SourcesDaniel Davis, Jr., Davis's Manual of Magnetism (Boston: Daniel Davis, Jr., 1842), 73-75, 145-153.
Daniel Davis, Jr., Catalogue of Apparatus, to Illustrate Magnetism, Galvanism, Electrodynamics, Electro-Magnetism, Magneto-Electricity, and Thermo-Electricity (Boston: Daniel Davis, Jr., 1848), 14, fig. 167.
Daniel Davis, Jr., A Manual of Magnetism, 2nd ed. (Boston: Daniel Davis, Jr., 1848), 172-173, 254-263.
Daniel Davis, Jr., Davis's Manual of Magnetism, 7th ed. (Boston: Palmer and Hall, 1855), 172-173, 254-263.
Daniel Davis, Jr., Catalogue of Apparatus, to Illustrate Magnetism, Galvanism, Electrodynamics, Electro-Magnetism, Magneto-Electricity, and Thermo-Electricity (Boston: Daniel Davis, Jr., 1848), 14, fig. 167.
Daniel Davis, Jr., A Manual of Magnetism, 2nd ed. (Boston: Daniel Davis, Jr., 1848), 172-173, 254-263.
Daniel Davis, Jr., Davis's Manual of Magnetism, 7th ed. (Boston: Palmer and Hall, 1855), 172-173, 254-263.
ProvenanceFrom the Department of Physics, Harvard University.