in 1888. The US Patent Office affirmed Hopkinson's claim to priority of invention, but his British patent expired before the case was resolved, rendering him ineligible for a US patent (his US patent, had one been issued, would have expired concurrently with his British patent). 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. Personal life and legacy 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. As a memorial to John Hopkinson and his son, the 1899 extension to the Engineering Laboratory in the New Museums Site of the University of Cambridge was named after him. A plaque commemorating this is fixed to the wall in Free School Lane. The Hopkinson and Imperial Chemical Industries Professorship of Applied Thermodynamics is named in his honour. There is a memorial sundial to Alice Hopkinson in the gardens of Newnham College, Cambridge from which she had recently graduated; the Lina Evelyn Hopkinson Scholarship is awarded to pupils at Wimbledon High School for English Literature. At the Victoria University of Manchester the Electro-technical Laboratory (1912) in Coupland Street was named after him. His sons Bertram and Cecil, wife Evelyn and daughter Ellen (married James Alfred Ewing in 1912) are buried in the Ascension Parish Burial Ground, Cambridge; the rest of the family are interred in Switzerland. See also Electric motor Three-phase electric power Polyphase system Rigid collectors Bertram Hopkinson, his son Alfred Hopkinson and Edward Hopkinson, his younger brothers Austin Hopkinson, his nephew References Further reading Hopkinson, Mary & Ewing, Irene, Lady (eds.) (1948) John and Alice Hopkinson 1824-1910. London: Farmer & Sons, printers External links John Hopkinson John Hopkinson Biography 1849 births 1898 deaths Scientists from Manchester Alumni of Trinity College, Cambridge Alumni of the University of London English scientists Fellows of the Royal Society English electrical engineers English physicists Academics of King's College London Mountaineering deaths Sport deaths in Switzerland Royal Medal winners Senior Wranglers John