Land Survey Control. During the reconnaissance, evidence was recovered of the triangulation network maintained on previous mapping and control surveys. In general, a network appears to have been established from island to island, and extended out into the lagoon to include the coral head photo tower and another low tower structure which was used solely as a survey observation point. The monuments used in this triangulation survey are still recoverable. They consist of three inch brass plates of standard US Coast Survey type set in concrete flusn with the ground. The survey observation point in the lagoon is constructed of a circular sheet pile enclosure approximately ten feet in diameter, apparently filled with coral to avoroximately eight feet above the sea level and capped with concrete. The condition of this installation is fair. No bench marks for vertical control were discovered, and it is not believed that tide observations are being taken at the present time. Horizontal Control. this area. Two horizontal control surveys have been made in An analysis of the methods and results of these surveys indicate that they do not meet the new requirements of this project. U.S. Naval Control Survey. 194. A survey by the USS Bowditch was made in This survey included a triangulation network covering that portion of the Atoll east of Bogombogo on the north and Igurin on the south. The apparent purpose of this survey was a hydrographic chart of the Atoll. The survey was of third order accuracy and consisted of a base line on Runit island and triangulation stations on nine other islands. As the loca- tions of control points are not readily adapted to the requirements of this project and some stations have been destroyed, retracing this survey is not recommended. II = 10