John Hopkinson

Background

Hopkinson was born on July 27, 1849 in Manchester, England, the eldest of 5 children. His father, also called John, was a mechanical engineer.

Education

Hopkinson was educated at Queenwood School in Hampshire and Owens College in Manchester. He won a scholarship to Trinity College, Cambridge in 1867 and graduated in 1871 as Senior Wrangler, having placed first in the demanding Cambridge Mathematical Tripos examination. During this time he also studied for and passed the examination for a BSc from the University of London. Hopkinson could have followed a purely academic career but instead chose engineering as his vocation. He was a Cambridge Apostle.

Career

In 1872 Hopkinson undertook the duties of engineering manager in the glass manufactories of Chance Brothers and Company at Birmingham. In 1877 Hopkinson was elected a Fellow of the Royal Society in recognition of his application of Maxwell's theory of electromagnetism to problems of electrostatic capacity and residual charge. In 1878 he moved to London to work as a consulting engineer, focusing particularly on developing his ideas about how to improve the design and efficiency of dynamos. Hopkinson's most important contribution was his three-wire distribution system, patented in 1882. In 1883 Hopkinson showed mathematically that it was possible to connect two alternating current dynamos in parallel - a problem that had long bedevilled electrical engineers. He also studied magnetic permeability at high temperature, and discovered what was later called the Hopkinson peak effect. Hopkinson twice held the office of President of the Institution of Electrical Engineers. During his second term, Hopkinson proposed that the Institution should make available the technical knowledge of electrical engineers for the defence of the country. In 1897 the Volunteer Corps of Electrical Engineers was formed and Hopkinson became major in command of the corps. Dr Hopkinson presented a rare combination of practical with theoretical ability, and his achievements in pure scientific research are not less intrinsically notable than the skill with which he applied their results to the solution of concrete engineering problems. His original work is contained in more than sixty papers, all written with a complete mastery both of style and of subject-matter. His name is best known in connexion with electricity and magnetism.

Achievements

• Hopkinson invented the three-wire (three-phase) system for the distribution of electrical power, for which he was granted a patent in 1882. He also worked in many areas of electromagnetism and electrostatics. Hopkinson's law, the magnetic counterpart to Ohm's law, is named after him.

Membership

Fellow of the Royal Society

Connections

On 27 August 1898, Hopkinson and three of his six children, John Gustave, Alice and Lina Evelyn, were killed in a mountaineering accident on the Petite Dent de Veisivi, Val d'Hérens, in the Pennine Alps, Switzerland.

Father:

John Hopkinson

Daughter:

Lina Evelyn Hopkinson

Daughter:

Alice Hopkinson

Son:

John Gustave Hopkinson

References

• Dynamic Electricity, Its Modern Use and Measurement, Chiefly in Its Application to Electric Lighting and Telegraphy: Including: I. Some Points in ... Purposes; III. Electric Light Arithme
• John and Alice Hopkinson 1824-1910