On 31 January 1950, President Truman made public the decision to develop a thermonuclear bomb, a decision which, of course, was to have great impact on Eniwetok Atoll. Test of weapons with such large increases in yield and fallout radiation are not suitable for tests on the continental United States, but are better suited for the remoteness of the Pacific Proving Ground. To facilitate tests of devices that at first were limited to the 20-kiloton nominal yield of the Hiroshima weapon, the Nevada Proving Ground, near Las Vegas, Nevada, was additionally established in the autumn of 1950. The first tests there were in a 1951 series starting on 27 January. The Eniwetok Atoll test series also planned for 1951 was designated as Operation Greenhouse and included, among other tests, activities related to thermonuclear research, but not yet involving a full thermonuclear explo$ sion. Between 7 April and 24 May 1951, four tests from towers were conducted wee TLS Lk ate CAR FREE EE eof ate ate WW Ee 2 ee DE ete ee Tt wa OT, eee ba CY acne 2 PLR bbadash ET mrs AD eee Ute ee A full thermonuclear explosion was achieved the following year in the 1952 test series Operation Ivy at Eniwetok Atoll 428 This involved only two tests, but ones of considerable significance and consequences. The first was Test Mike, the first thermonuclear detonation , which was a ground level explosion amounting to 10.4 megatons (equivalent of 10.4 million tons of high explosive) on 1 November 1952 ona small island, Elugelab (Eluklapin in Marshallese, and Flora by the U.S. code name), at the north end of the Atoll. Being a surface explosion and having this large yield, Test Mike actually removed this small island from the Atoll chain. A large reinforced concrete building built on the nearby large island of Engebi to test effects of pressure was partly damaged. The second test of Qperation Greenhouse was a "high yield" explosion, Test King, from an air drop over Runit Island. 7. 8. Reference 1, p 125. Reference 1, p 135. BEST AVAILABLE COPY (3)