by precipitating the fog by means of en electrostatic field onto a con~tinuously moving, specially sensitized film. Film reels were later removed from precipitator sampling for signal from the device, developed, and analyzed, The electrostatic vas powered by a 1 KVA motor generator and was capable of a maximum of 6 hr. At island stetions it was started by a a light trigger and manually on the YAG's, The uutomatic water drop collector was a device for collecting raindrops in flour filled trays when they were retained as pellets of dough. After a pre-determined numper of rain drops had been collected, the device automatically changed trays. The collector was started by a signal from a light trigger. The mechanism for changing trays was driven by compressed gas and was criggered by arain drop contacting a sensitive element. The area of the sensitive element was adjusted so that there was a high probubility that a tray would be changed only after a pre-determined number of drops had fallen into it. 3.1.6 Triggers The corincipal trigger was a light-activated device consisting of ‘ peteges yheady a trigger box, and a battery and pover cable assembly Fig. 303) ger. . A prototype radicticn trigger was also tested as a back-up trigIts sensitivity was so high thet it could not be used on the ccn- tuminated islands efter Shot 1. It may prove to be satisfactcry after some modifications. Simple pressure-ectuated trigsers were designed and ccnstructed at the site to elleviute the shortage of triggers that occurred when eparesc vere burned cfter shot 1. 3.1.7 » Free-flosting Buoys Free-floating buoys vere used as collection stations in the sea areas around Sikini atoll. Figure 3.4 shows the following details of construction: Flatform to mount the gummed paper collector; antenna whips; antenne coils; identification flag; total collector; buoy float contsining the radio transmitter and bettery nower; and keel mount. Not shown are the weight «t the bottom of keel rount and the film badge on the mast 2 ft above deck, The identifiers on the floats were single-stuge crystal-controlled radio transmitters, operating on the following autnorized frequencies* 1309.375, 1243.75, 1206.25, 1159.375, 1129.375, 1087.5, 1062.5, 1026.875, 987.5, and 741,875 ke. These units had a useful life of 4 to 6 days before the batteries had to be re-charged. The buoys were identified end located by radio cir_ction-finding gear avoard Naval Task Uroup chips and aircraft. 3.2 EVALUATION CF STATIONS AND EQUIPMENT It is difficult to mike a fair evalustion of the station and equipment at CASTLE because numerous chanses in shot scheduling and the * Circuit Wo. J113, assigned ty letter from Headquarters, TG 7.1, JIF-7, J-22227, 15 Dec. 1953, 39