electromagnet comparitor
Date: circa 1840
Inventory Number: DW0067
Classification: Electromagnet
Subject:
Maker: French ?
Cultural Region:
Dimensions:
18.5 × 30.8 × 18.2 cm (7 5/16 × 12 1/8 × 7 3/16 in.)
Description:
A three-bar compound horseshoe magnet, oriented horizontally. On top, near the open end, a metal bar on top of which is a wooden handle. A dark green electromagnetic coil can be found on each end of the horseshoe magnet. The coils are connected from behind by a metal bar, which connects to an L-shaped support. Together, they form the magnet's keeper, or armature. The support is mounted onto the rectangular wooden base. On the same side of the base as the support are two brass binding posts.
Signedunsigned
FunctionThe soft iron bar with the wooden handle can be moved along the compound horseshoe magnet. Depending on where it is, it increases the magnetic field (stronger towards the pole). The increase or decrease is detected by the vibrating metal bar fixed on the coils, acting as the armature to the horseshoe magnet.