Late Victorian Arago's Disc Physics Demonstration Apparatus by Harvey & Peak London

For sale, a Late Victorian Arago’s Disc Physics Demonstration Apparatus by Harvey & Peak of Beak Street London.

An interesting and seldom seen piece comprised of a mahogany base with a large and a small pulley connected by a leather band. The large pulley is rotated by means of a handle and the smaller pulley is attached to a copper disc, over which a mahogany housing is set with a glass plate and central pin on which a magnetic strip is balanced.

The reaction between a magnet and other non-ferrous material led to the discovery of eddy currents in 1824 by the French scientist, Francois Arago. This ground breaking work in the field of magnetism earnt him the much famed Copley Medal from The Royal Society in 1825 and further work revealed that a rotating copper disc could communicate its motion to a magnet suspended over it. Aptly titled “The magnetism of rotation” by Arago at the time, it was further explained by Michael Faraday in the early 1830’s with his theories on electromagnetic induction.

This working example retains the maker’s plate for Harvey & Peak, successors to W. Ladd & Co, Beak St, London and a further small brass plaque with the the initials UCSW and inventory number 215. The acronym is for The University College of South Wales (now Cardiff University) formed in 1883 which aligns nicely with the date at which Harvey & Peak purchased William Ladd’s scientific instrument making business in 1882. The low inventory number suggests also that Harvey & Peak were one of the chosen suppliers for kitting out the University’s science department following its inauguration.

The history of the manufacturer traces its roots back to the 1840’s with William Ladd who was instrumental in early experimentation with electricity for industrial purposes. He was successful enough to have exhibited at The Great exhibition and the Paris Exposition and was a prominent member of numerous scientific societies during his career.

Surprisingly little is known of Harvey & Peak’s early careers, it is likely that they were involved as workers of foreman in William Ladd’s business prior to their takeover in 1882 and Ladd’s retirement. Evidence suggests from various first hand sources that they continued Ladd’s appointments with The Royal Institution and the use of their services by Universities and scientist in their early trading period all point to an enduring level of confidence and trust in the successor’s abilities.

They continued to trade from Beak Street from 1882 until 1891 whereafter they moved to Charing Cross Road. The partnership was dissolved in 1899 but William George Harvey maintained the business until 1909.

This example is from their earliest period of trading and is likely to date to 1883 in reference to the initial acquisitions made by the University College of South Wales.