Harry Collingwood was the pseudonym of William Joseph Cosens Lancaster (23 May 1843 - 22 June 1922), a British civil engineer and novelist who wrote over 40 boys' adventure books, almost all of them in a nautical setting. Collingwood's first novel in 1878, the year of his marriage, was The Secret of the Sands, a tale of the sea with piracy and buried treasure thrown in. The hero and pseudonymous author of this tale was "Harry Collingwood". This pseudonym was chosen by the author in homage to Vice-Admiral Cuthbert Collingwood. This was clearly intended as an adult book. At the time, adult books were typically produced in three volumes, whereas books for the juvenile market were typically produced in a single volume with illustrations.