economical for the relatively short period of time for which these facilities will be used. EXPERIMENTAL STRUCTURES: Condition of Existing Structures. The reconnaissance trip, recently made, revealed that with minor repairs, all of the existing experimental structures can be re-used. It was recorded on this survey that the Timing Buildings were leaking around the doors. Repairs to the topside structure of Coral Head Photo Tower are required, and the existing hoist is in very bad condition. Maintenance painting on the other two existing Photo Towers is needed. Air conditioning units for Timing Buildings are partially dismantled, and some of the parts have disappeared. Asphaltic coatings on limonite concrete Gamma stations are badly peeled. Recommended Repairs. The Timing and Gamma Buildings should immediately have new vubber gaskets fitted around door openings so that a tight seal can be obtained. Also, it is recommended that canopies be constructed over doors to divert water from top of doors. Radiation shields for doors of Gamma Buildings, truck mounted, and made to operate on tracks should be provided prior to any future experiment. Tracks should be graded so trucks will move toward the door by gravity and move back by winch. Asphaltic coatings on limonite concrete structures should be immediately repaired. Painting of existing Photo Towers should be completed with Zinc Chromate type paint so that they will be maintained in usable condition. New air conditioning units should be provided for Timing Buildings and any Iv - 35