Silston Cory-Wright was born at Sigglesthorne Hall, Hornsea, Yorkshire, England, on 22 September 1888, the son of George Henry Cory Wright and his wife, Ellen Green Wade. He was registered by his father at birth as George Sigglesthorne Wright, but his mother disapproved and he was baptised Silston. Later the family name became Cory-Wright and he was known as Cory. His mother was widely read and taught him several languages. George, a farmer of independent means, managed his family's estates, the income from which had been largely invested in Canadian enterprises. In the late nineteenth century the companies incurred heavy losses, influencing the family to move abroad. After living in Norway, Jamaica and Morocco, they returned to England.
In 1905 Silston went to Zurich to do an engineering apprenticeship with Escher Wyss and Company. While serving his time, he studied for the University of London matriculation examinations and climbed mountains on Sundays. When he had trained as a design draughtsman he spent two years at the University of Birmingham, and in 1908 he gained a BSc in engineering from London University. He then supervised the installation and commissioning of Escher Wyss equipment at Kinlochleven power station for Britain's first aluminium smelter at Fort William, Scotland. By 1910 he had become an associate member of the Institution of Civil Engineers, London.
Cory-Wright was in Zurich in 1910–11 designing turbines. During this period a senior engineer with the New Zealand Public Works Department visited Switzerland, and he was detailed to show him the Albula hydroelectric station, which supplied Zurich. The station was similar to one planned for Lake Coleridge, the first hydroelectric station to be built by the New Zealand government.
Cory-Wright's parents had already emigrated to New Zealand when in 1912 he accepted an appointment as a lecturer in the new associateship in engineering course at Auckland University College. He retained his connection with Escher Wyss, though, and between 1913 and 1923 negotiated the sale of the first six Lake Coleridge turbines, which were based on the Albula design. When the German-born Swiss installing the turbines was interned at the beginning of the First World War, Cory-Wright was asked to supervise the installation and maintenance of the initial three units. In November 1915 he joined the Corps of New Zealand Engineers, and in 1916 served in Egypt and France. Owing to his fluency in languages, he was seconded in early 1917 as an intelligence officer to the New Zealand Division in France. By the end of the war he had been promoted to captain and had won the Military Cross for frontline duties.
In 1920, after a brief return to lecturing, Cory-Wright joined Cedric Salmon, a fellow officer in the Engineers, in founding the engineering firm of Cory-Wright and Salmon. The business was based on the partners' contacts with such major British firms as Vickers Limited and the English Electric Company, but it also represented over 50 other large engineering concerns. It supplied a diversity of equipment, especially for railways: electrical components for the Lyttelton–Christchurch line (1928), electric units for the Wellington–Johnsonville line (1938), and electric locomotives for the main trunk line beginning with Wellington–Paekākāriki (1939–40).
Contracts were also obtained through Cory-Wright's interest in hydro development. On behalf of the firm he supervised Escher Wyss turbine installations at Lake Coleridge until 1923, and subsequently many hydroelectric units for English Electric. By the 1950s he had been associated with every significant South Island power station and with several in the North Island. His experience was acknowledged overseas: in the 1930s he advised on remedial measures after a major hydraulic failure in Tasmania. He was closely involved with the firm he cofounded until his death in 1976. The partnership had become a private company in 1931 and a public one in 1951. The firm was taken over by Tatra Industries Limited in 1983–84, and went bankrupt in 1988.
Cory-Wright was married in Auckland on 4 December 1924 to Jean Isobel MacLennan. From 1928 the couple lived in the historic crescent-shaped Wellington residence known as 'the banana house'. Cory-Wright was a strong supporter of trade and professional organisations. He served on the council of the British Trade Association of New Zealand, was a fellow of the New Zealand Institution of Engineers, and a regular attender at its meetings. He was also an active Freemason for many years. In 1924 he was awarded the Royal Humane Society of New Zealand’s medal for rescuing a non-swimmer in the sea off Tairua, Coromandel Peninsula, where his parents owned land.
His wife died in 1970. Cory-Wright died in Wellington on 3 March 1976, survived by two sons. Later some 20 boxes of memorabilia were presented to the Alexander Turnbull Library.