The device serves to reproduce the phenomenon by which Hans Christian Oersted (1777 – 1851) demonstrated in 1820 that a magnetic field is generated by an electric current passing through a conducting wire.

The lathe-turned wooden base supports a horizontal rod that bears a glass column at either extremity; these end with two terminals in which a thick copper wire is inserted. In the centre of the support there is a tip which holds a magnetized pointer; the height of the support is adjustable, so that the distance of the needle below the conducting wire may be varied.

After aligning the wire with the magnetized pointer (which initially indicates Magnetic North), if the wire is connected to the terminal of a battery so that current flows, the pointer changes direction due to the influence of the magnetic field generated by the electric current. The closer the pointer is to the wire and the stronger the current, the greater the deviation observed.

Device on display.