procedures of the U.S. Coast and Geodetic Survey for second order base line measurement. The computed probable error of total measurement of the line was one part in 646,000. The allowable maximum probable error for second order base line measurement is one part in 500,000. The geographic position of station RUNIT as determined by the USC & GS survey was adopted as the origin of geographic position. The azimuth values of this survey for the line, station RUNIT to station SAND were adopted as the origin of geodetic azimuth. The probable accuracy of the adopted values for position and azimuth are not known, but it was considered that the accuracy was consistant with project requirements at the time, and the a Repreduced fro mthe holdings of the National Archiv es, Pacific Southwest Region fy expense of further refinement could not be justified. The computed closing error of the survey before adjustment was determined as approximately one part in 25,0CC. An additional check was. obtained in 1952 by inclusion of a first order traverse in the FLORA-GENE area. This indicated a closing error of approx- imately one part in 70,000 before adjustment of the adjacent quadrangle. In order that the values of a station would remain the same independent of the direction of computation through the net, an adjustment was applied to the triangulation figures. This consisted of a side equation adjustment which resulted in slight changes in the values previously reported. A plane grid was established in 1952 which was common to the entire Atoll, and from which the inter-relation of structures and areas, and their positions could be specified by plane coordinates. (2)