double-beam axial electromagnetic reciprocating engine
Datecirca 1848
Inventory Number1997-1-1801
ClassificationEngine Model
Subject
Attributed to
Daniel Davis, Jr.
1813 - 1887
Cultural Region
Place of Origin
Dimensions19.7 × 35.6 × 17.7 cm (7 3/4 × 14 × 6 15/16 in.)
Material
Bibliography
DescriptionTwo horizontal beams fixed on brass columns support a pair of iron rods that go in and out a pair of electromagnetic coils. The motion of each beam is communicated, by means of a crank, to a toothed wheel. One of these wheels is equipped with an electrical interrupter. A third toothed wheel, linked to the other two, is connected by an axle to a fly-wheel that can also be turned by hand. There are two binding posts to which were connected a battery.
The instrument has two old Harvard numbers: "6-4-7" and "7-20".
In 1848, Davis sold this instrument for between $15 and $18.
The instrument has two old Harvard numbers: "6-4-7" and "7-20".
In 1848, Davis sold this instrument for between $15 and $18.
Signedunsigned
Curatorial RemarksBought by Harvard from Daniel Davis, Jr. in 1850, with a set of other scientific instruments. Though unsigned, this instrument is identical to the one mentioned in Davis's book <i>A Manual of Magnetism</i>, fig. 124, p. 183. It does not appear, however, in the first edition of 1842.
FunctionThis demonstration apparatus was used to show how magnetic induction was produced by an electric current.
A battery was connected to the two binding posts, providing an electric current to the two double-coils at each end of the base. When electricity passes through one of the coils, it creates a magnetic field that attracts the pair of vertical iron bars inside the coils. This vertical motion is transmitted to one of the toothed wheels via a horizontal beam. An interrupter (or break-piece in Davis's words) allows the electric current to alternate between the two double-coils. As the video shows, the alternate motion of the horizontal beams is communicated to a large fly-wheel by means of the toothed wheels moved by cranks.
A battery was connected to the two binding posts, providing an electric current to the two double-coils at each end of the base. When electricity passes through one of the coils, it creates a magnetic field that attracts the pair of vertical iron bars inside the coils. This vertical motion is transmitted to one of the toothed wheels via a horizontal beam. An interrupter (or break-piece in Davis's words) allows the electric current to alternate between the two double-coils. As the video shows, the alternate motion of the horizontal beams is communicated to a large fly-wheel by means of the toothed wheels moved by cranks.
ProvenanceFrom Jefferson Laboratory, Harvard University.
Daniel Davis, Jr.
Date: 1848-1855
Object number: 0120
Daniel Davis, Jr.
Date: circa 1848
Accessories: battery (0566b); pair of shock handles (0566c,d)
Object number: 0566a
