zero line seventy-five feet beyond center of tower used in previous experiment. Plates 19, 20, 21 ami 22 show recommerded location of four Zero Towers. How} ever, the possibility of locating towers off islands on reefs was investigated and found to be practicable, providing the site is so selected that necessary fill for tower area and causeways can be made without excessive cost. The economic balance of land to offshore location comes when the cost of fill required for offshore site equals the cost of paving around shore tower and the regrading operations for decontamination or future experiment. Samples of the soil were tested and evaluated, as shown on Plates 23, 2h, 25, 26 and 27. This data indicates that towers and anchors can be located on filled sites with bearing values of the compacted fill given the same magnitude as natural soil. It is recommended, therefore, that footings for the Zero Tower structure be designed for founding about four feet below the surface of the site and with inter-connecting struts to take the horizontal components of the loads in the battered legs. To enable field operations to proceed without delay regardless of conditions encountered at site, anchor footings should be designed to cover locations where they are founded in rock above high water level, in rock which may be submerged, in soil entirely above high level, in soil with anchor footing half submerged at high water level and in soil which will be entirely submerged at high water level. Photo Towers. Previous experiments demonstrated that the 75-foot high Navy type Radar Tower was suitable with minor alterations. It is, therefore, recommended that this type be used with alterations as hereinafter noted. The two existing Photo Towers that are erected at Coral Head and Aniyaanii locations should be remodeled to cover criticisms appearing in the Technical IV - 39