William R. Quinan, explosive technologist and inventor, was a son of the medical practitioner Dr John R. Quinan and his wife Elizabeth Billingsley. He studied at the West Point Military Academy, New York, graduating in 1870 with distinction in mathematics and the natural sciences. During the next ten years he served in the United States artillery and specialised in the use of dynamite, then a recently developed industrial explosive. After resigning his commission in 1881 he became superintendent of the Hercules Powder Works at Pinole (just north of Oakland, California), belonging to the California Powder Company. He held this position from 1883 to 1899, during which time he established his reputation as an explosives technologist. In addition he wrote an interesting paper on thermometry, "Some physical aspects of the new gas argon: The ideal thermometrical substance for high temperatures" (Journal of the American Chemical Society, 1895). He married Caroline de Witt in 1873 and they had a son and two daughters. After her death he married Sarah Stanford in 1903.
In 1899 Quinan was given a contract by De Beers Consolidated Mines to set up an explosives factory in the Cape Colony, with the idea of breaking the monopoly of the Nobel Dynamite Syndicate with its factory at Modderfontein in the South African Republic (Transvaal). He arrived in Cape Town in July 1899, with his materials following in August. A site for the new factory was purchased near Somerset West, but local opposition and the outbreak of the Anglo-Boer War in October 1899 delayed the project. The factory was eventually completed in 1903, with production starting in August that year. Quinan held the position of General Manager. Originally named the De Beers Explosive Works, it was renamed the Cape Explosive works in 1906.
Quinan became a foundation member of the South African Association for the Advancement of Science in 1902. During the next few years his health deteriorated and his responsibilities were gradually taken over by his nephew, Kenneth B. Quinan*, who had joined the project in 1901 and who succeeded him as general manager in 1909. In 1908 William went to Europe on long leave, from where his board of directors sent him to Australia to sell the company's explosives there. His success in obtaining contracts led the company to buy a ship of 2000 tons in 1909, which for many years transported explosives from South Africa to Australia.
Quinan died in Australia in 1910, but his body was brought back to Somerset West for burial. At the time of his death he was working on a book, High explosives, which was published in Melbourne in 1912. Its publication was preceded by a paper with the same title in the South African mining Journal for July-October 1910 and as a pamphlet (Johannesburg, 1910, 18p). Among his inventions were the Quinan packing machine for packing dynamite into cartridges, and a test for explosives based on measuring their crushing effect on a specified metal block. The factory which he started later became the second largest of its kind in the world and with its expansion into chemical fertilisers and other products made a significant contribution to the industrial and agricultural development of South Africa.