south of Runit, as this island is the nearest one to Parry Island having sufficient length to locate the Timing Station one thousand yards away from zero. Going north, the next group of islands having sufficient length is that consisting of Aomon, Biijiri and Rojoa. for operation Sandstone. This groun can be used again as it was The requirement of three miles between towers elimi- nates all islands between Aomon and Engebi. ments and was used in earlier tests. <ingebi Island meets the require- Therefore, the three previous locations can be re-used and it is necessary to go to the west to select another island to be used for the fourth location. If the Zero Tower were located near the west end of Elugelab Island, sufficient distance could be obtained by placing the Timing Station on Teiteiripucchi Island. There is considerable water distance between these islands requiring a much longer causeway than was constructed between Aomon and Biijiri for Sandstone. Another possible location is Bogallua Island which is at the extreme west end of the chain of islands at the north. There is a samd spit extend= ing from the west end of this island that is not shown on a map published by the Hydrographic Office of the U. 5. Navy in March 1946, but by examination of aerial photographs made in October 197 and by observation of the reconnaissance party in October 1948, it appears evident that this spit exists and may be considered permaent. Locating the Zero Tower near the west end of the spit, the Timing Station can be olaced one thousand yards away. also space on this island for a camp and airstrip. There is A rather long approach is required to reach the edge of the reef on the Lagoon side, but a similar condition also exists at Elugelab. Bogallua Island seems more desirable, since no causeway is required and it is recommended as the selection for the fourth shot island. III = 4