Demonstration device for Arago's rotating discs, after Dominique François Jean Arago (1824)

London Watkins & Hill

In 1820 Hans Christian Oersted discovered that a magnetic needle deviates when it is near an electric current. Shortly afterwards, the French physicist Dominique François Jean Arago discovered that also a fast rotating disc made of non-magnetic material caused a deviation of a magnetic needle. This phenomenon can be demonstrated with this instrument. The disc rotates just beneath a glass plate on which a magnetised needle is placed. The position of the needle deviates from the magnetic meridian and above a certain speed of rotation the needle also rotates. Eventually, it was Michael Faraday who found an explanation for this phenomenon. The behaviour of the needle is a result of the fact that so-called induction currents (currents generated by a magnetic field) are formed in the disc. Arago's disc is applied, for example, in the drive of electric clocks, and the construction of electromotors.

Administration name

Fysisch Kabinet

Title

Demonstration device for Arago's rotating discs, after Dominique François Jean Arago (1824)

Translated title

Demonstration device for Arago's rotating discs, after Dominique François Jean Arago (1824)

Creator

[{'date_of_birth': u'', 'role': u'', 'qualifier': '', 'date_of_death': u'', 'creator': 'Watkins & Hill, London'}]

Production notes

1843

Material

[{'material': 'ivory'}, {'material': 'Wood'}, {'material': 'brass'}, {'material': 'Glass'}]

Object number

FK 0470

Reproduction reference

[{'reference': '..\\images\\Fysisch\\Gekoppelde afbeeldingen\\FK 0470.jpg'}]