If we arbitrarily divide Yeats's fifty-four years of publishing into thirds, “late Yeats” would cover the years 1920-39. By 1920, when he was fifty-five, Yeats felt that his heart had grown old (as he said in “The Wild Swans at Coole”). He had given up his hope to marry Maud Gonne (to whom he had proposed, for the last time, in 1916), had married George Hyde Lees, had become a father at the birth of his daughter Anne, and, when lecturing in America, had seen his failing father for the last time (J. B. Yeats died in 1922). Yeats had already moved into a retrospective mode by writing, in 1914, the first of his autobiographical essays, called Reveries over Childhood and Youth, to be followed, in 1922, by The Trembling of the Veil. He was spending summer weeks in his tower at Ballylee, making it his symbol of age, endurance, fortitude, and wide observational power. He and his wife were ardently pursuing the practice of automatic writing, which had led, in 1918, to the first sketch - called Per Amica Silentia Lunae - of the occult materials that would receive their fullest form in the 1926 publication of A Vision.