Some interesting authors going into the public domain in early 2018, having died in 1947:
Arthur Machen. (The biggest name for 2018).
Emilio Carrere (The Tower of the Seven Hunchbacks, later a cult film).
Laurence D’Orsay (wrote some ghost stories, had two stories in Weird Tales in the mid 1920s).
Alfred North Whitehead (a British philosopher whose 1920s works influenced H. P. Lovecraft).
J. D. Beresford (prolific novelist, admirer and imitator of H.G. Wells — though with less ‘megaphone socialism’ and more human sympathy. Apparently an influence on Stapledon. His The Hampdenshire Wonder sounds very similar to Wells’s The Wonderful Visit and appears to anticipate The Midwich Cuckoos. Also wrote ghost/mystery stories).
M. P. Shiel (The Purple Cloud, a landmark in science fiction, and a number of fantastical stories such as “The Pale Ape”. Lovecraft thought his “The House of Sounds”… “the most haunting thing I have read in a decade.” when he read Shiel circa 1923).
John Ulrich Giesy (wrote stories for the Munsey proto-pulps and early 1920s pulps).
English rural supernatural/magic:
Forrest Reid (his finely-written Tom “trilogy partakes heavily of the marvellous, involving nature worship, guardian angels, ghosts, magic arts and the bridging of the dream and real worlds”).
Hugh John Lofting (the Doctor Dolittle series, and the historical novel The Twilight of Magic about medieval England transitioning from magic to science).
Charles Henry Cannell (wrote as Jack Mann the ‘Gees’ series of rural supernatural detective novels, in which Gees battles warlocks and werewolves. Also a classic telling of the Adventures of Robin Hood for children).
Herbert Asquith (Wind’s End was the first novel of this son of the Prime Minister, “a novel of violence, mystery and crime detection” in rural England … “also a touch of the mystical here” … “unusually good in rustic characters”).
Adventure and true-life:
Emma Orczy (series of Scarlet Pimpernel novels and stories).
E. M. Hull (desert adventure novels).
John Alden Loring (African Adventure Stories, written from first-hand experience as a field naturalist).
James Willard Schultz (sympathetic and ethnologically-accurate adventure novels of American Indian life and fur traders in the Old West).
Alan Sullivan (lost world novel, and a minor fantasy novel).
Charles Nordhoff (gritty sea adventure in the Mutiny on the Bounty trilogy of novels).
‘Captain Dingle’ (authentic sea adventure stories written for the Munsey-era proto-pulps by a veteran sailor).
John Henry Patterson (the true-life The Man-eaters of Tsavo and Other East African Adventures, filmed three times).
Cecil Madigan (the true-life story of exploring then-unexplored Australia, Crossing the Dead Heart).
Also of note:
Hector Munro Chadwick (his theory of The Heroic Age, in book form in 1912, was an influence on the young Tolkien and tangentially the later sword-and-sorcery genre).
Marie Adelaide Belloc Lowndes (sister of Hilaire Belloc who produced a popular mystery-crime novel a year, one of which became an early feature-film by Alfred Hitchcock).
Margaret Marshall Saunders (an enormously popular children’s animal-story adventure writer from Canada, now forgotten).
Henry Ford (the famous manufacturer, autobiography ‘My Life and Work’ and ‘My Friend Mr Edison’ – his ghost writer Samuel Crowther also died 1947).
Harry Gordon Selfridge (The Romance of Commerce, a popular book-length survey of ancient commerce from Greece onwards, Bodley Head. Might be suitable for adaptation as a non-fiction graphic novel?)
Angela Brazil (cult stories of English girls’ school life, the Chalet School series).
Flora Thompson (Lark Rise to Candleford, Candelford trilogy)
Donald Henderson (“the 1943 psychological thriller Mr. Bowling Buys a Newspaper, which got considerable critical attention in wartime Britain”).
Meredith Nicholson (the best-selling ‘haunted-house/inheritance/romance’ mystery The House of a Thousand Candles, and mystery/espionage thriller The Port of Missing Men).
C. Louis Leipoldt (a major Afrikaans poet whose poetry does not translate, but he also wrote “detective stories”. His English-language historical fiction Boer trilogy The Valley was only published posthumously and with radical surgery to the original drafts, and thus will not be going into the public domain).
Iain MacCormaic (wrote the first novels in Scottish Gaelic).
Bert Kalmar (songwriter for Groucho Marx).
John Archibald Watt Dollar (A Handbook of Horse-Shoeing, 1898 but not likely to be out-of-date due to the traditional nature of this rural craft).
In the USA, the 1960s playwright Joe Orton enters the Public Domain.