map involved was revised and reissued. 23 x 34 inches in size, Thirty-seven location maps, were required to depict the exact location of the 839 stations, As the many experimental programs were developed and the use of additional islands became necessary, additional survey work was required, In many cases, stations were located on islands other than those containing zero towers, and a complete triangulation survey was required to determine the distance and direction of the stations from zero. These were unique engineering and planning problems, Not only was the number of scientific stations being continually increased and their locations being frequently changed, but the types of structures and kinds of construction were many and varied, There were practically no structures which could be said to be of normal construction. The purpose of the particular experiment, the problem of shielding from radiation, the location of the structure with relation to the zero towers, the blast pressure, the heat given off by apparatus within the structures, and many other special requirements governed the material of which the structure was to be built and the engineering design necessary. Not only did the development of the many scientific programs call for an almost continuous series of revisions, changes, and new designs for the experiment islands and scientific stations, but also the designs for camps on Parry and Eniwetok Islands were far from stable, As a natural result of the continually increasing scope of the scientific program, the number of people participating kept increasing. Each new group required laboratory and shop facilities, The addition of JTF-3 headquarters on Parry cailed for anotner administration building, The decision that drone planes would operate from Eniwetok greatly increased the Air Force requirements for housing, laboratories, shops, radar, and other facilities, The inclusion of animals in the experiments resulted in the development of Japtan Island as an animal colony and headquarters for the Medical-Biological group. These changes and additions caused many revisions to the plans for the non-experimental islands so that although the planning of these islands was started on March 5, 1949, and the design of the buildings was started on April 4, 1949, it was September 29, 1950, before the engineering design for these islands was finished, and the design of scientific stations was still in progress at the beginning of 1951, Another feature which added to the complication of completing designs was the distance between the Zone of Interior and Eniwetok Atoll. Rapid communication by telephone, teletype, and air mail was possible between the H & N Home Office, representatives of the Laboratory, the AEC Engineering & Construction Division, and the many representatives of Users; however, communication between the H & N Home Office and the Jobsite was somewhat slower, Teletype facilities were helpful within their limitations, but mail service, including the delivery of drawings, was slow and uncertain. In the early phases of the work, in fact through 1949 and the first portion of 1950, air transportation was irregular. Air mail passing through the APO system was frequently a week to ten days in arriving, 974 Even communications