Wade-Dahl-Till valve was partially built by the novelist of what nationality?
Roald Dahl Roald Dahl ( , ] ; 13 September 1916 – 23 November 1990) was a British novelist, short story writer, poet, screenwriter, and fighter pilot. His books have sold more than 250 million copies worldwide.
Fletcher Pratt Murray Fletcher Pratt (25 April 1897 – 10 June 1956) was an American writer of science fiction, fantasy and history. He is best known for his works on naval history and on the American Civil War and for fiction written with L. Sprague de Camp.