Alexander Raban Waugh (Alec Waugh) (1898 – 1981), was a British novelist, the elder brother of the better-known Evelyn Waugh and son of Arthur Waugh, author, literary critic, and publisher. .Read more on Wikipedia
Lowry refers to Waugh in a letter to Carol Brown dated May 1926 when he tells her about what Rev. Harry Bisseker, the Leys's Headmaster had been saying about him to W. H. Balgarnie treasurer and president of the Leys Fortnightly committee; "that...I had been reading Alec Waugh, but I had been reading Noel Coward, Michael Arlen, Eugene O'Neill, and Samuel Butler." (Collected Letters Vol 1 Pg. 25)
Lowry does not state which of Waugh's books he was reading - by 1925 Waugh had published The Loom of Youth (1917), Resentment Poems (1918), The Prisoners of Mainz (1919), Pleasure (1921), Public School Life: Boys, Parents, Masters (1922), The Lonely Unicorn (1922), Myself When Young : confessions (1923), Card Castle (1924), and Kept : a story of post-war London (1925).
The Loom of Youth was so controversial at the time (it openly mentioned homosexual relationships between boys). The book was based on Waugh's experiences and memories of Sherborne School, a public school in Dorset. The book was clearly inspired by The Harrovians by Arnold Lunn, published in 1913 and discussed at some length in The Loom of Youth.