Record number: 1686
Dimensions: 20 x 25 x 15 cm
Invented by P. Barlow in 1828 to demonstrate the action of the magnetic field on an electric current.
The object is mounted on a rectangular wooden base with four feet. It comprises a toothed copper wheel rotating around a moulded horizontal axle of gilded metal, which is submerged as it passes through the base of an iron container for mercury. The two poles of the direct current circuit, in gilded metal, are connected respectively to the mercury and to the axle. A magnet creates a normal magnetic field in the plane of the wheel, and it rotates, the direction of rotation depending on the respective directions of the magnetic field and the current.