Cline translated Platero y Yo (1916) by Juan Ramón Jiménez (1881-1958), who won the Nobel Prize for Literature in 1956. Platero y Yo is Jiménez's most famous work. It gives a portrait of life in the remote Spanish town of Mogeur, Spain, as the author speaks with his silver-grey burro, Platero. Cline translated it around 1922, and circulated the manuscript but it was never published and the manuscript is lost. In the 1930s, Eloise Roach fell in love with Platero y Yo, and also translated it, but similarly found no interested publisher. Her translation, as Platero and I, finally appeared in 1957, the year after Jiménez won the Nobel Prize.
In 1928, while serving time in the Tolland, Connecticut, Jail, Cline translated La Lámpara Maravillosa (1916) by Ramón del Valle-Inclán (1866-1936). It is a book spiritual exercises about Valle-Inclán's aesthetics. Cline's translation was turned down by the Viking Press, Covici-Friede, John Day Company, and Harcourt Brace & Company, and on 28 December 1928, just over two weeks before Cline died, his agent Bernice Baumgarten of Brandt & Brandt reported that they didn't think there was anything more to do with it, and were setting it aside. The translation, which Cline titled The Magic Lamp, remains unpublished, but a copy of the manuscript survives. The first published translation into English of La Lámpara Maravillosa was made by Robert Lima and it appeared in 1986 as The Lamp of Marvels.
Here is a copy of the title page of the translation Cline sent to his ex-wife Louise, to whom he was to be remarried, on 28 October 1928 (click on the image to make it larger):