the Amazonian "River of Doubt", in the footsteps of the 1913–14 Roosevelt-Rondon Scientific Expedition. Dyott wanted to verify Roosevelt's claim of discovering the river, for which there had been some doubt. The day after his marriage to Persis Wright in 1928, he mounted an expedition to search for the missing British explorer Percy Fawcett in the Amazon. Dyott found evidence he believed confirmed Fawcett had been killed by the Aloique Indians, but the strength of his evidence soon collapsed on closer scrutiny and the mystery of Fawcett's disappearance remained unresolved. Related to the Fawcett expedition, during which Dyott was held captive by Indians and barely escaped with his life, Dyott published a book about his adventures called Manhunting in the Jungle (1930), and also co-wrote and starred in a 1933 Hollywood action film called Savage Gold. The book was later adapted to film as Manhunt in the Jungle (1958). In 1929 Dyott played himself in a documentary called Hunting Tigers in India, filmed in India on the A. S. Vernay expedition under the auspices of the American Museum of Natural History. It was billed as "the first all-talking nature picture" and was supposedly shown to First Lady Mrs. Hoover in the White House theatre. Dyott was active in the early years of aviation in South America too. He established a company, Dyott & Company Ltd. of Lima, taking aerial photographs, scenic vistas and native scenes, which were sold as post-cards. Dyott retired to Santo Domingo de los Colorados, Ecuador, sometime in the mid-1930s. During World War II, Dyott returned to England in service of his country and a few years after the war's end retired once again to Ecuador. Dyott came out of retirement in 1947 and conducted his two final expeditions, which departed from Pillaro, Ecuador, venturing into the Llanganati Mountains in search of lost Inca Treasure. Dyott spent most of his life in South America but died in the city of his birth, New York City, in 1972. Works Books Possibilities of Aerial Transport in Peru (1919) Silent Highways of the Jungle: Being the Adventures of an Explorer in the Andes and Reaches of the Upper Amazon (1922) On the Trail of the Unknown. In the wilds of Ecuador and the Amazon. With plates and a map (1926) The Volcanoes of Ecuador, Guideposts in Crossing South America (1929) Manhunting in the Jungle, The search for Colonel Fawcett (1930)