and one 500-w spotlignt will be directed toward the optics stations on Engebi, Biijiri, and Parry. Taese spotlights will be used for tne alignment of optical equipment. ‘ In connection witn the King Shot it is desirable to measure the atmospheric transmission from the height of the air burst to the ground and the following procedure is planned: a 12-in.=diemeter Navy sig- nalling searcnlignt modulated at 60 cycles will be mounted at Aniyaanii and nand directed toward a nelicoptér flying either over the norta end of Parry or Biijiri. Mounted in tne helicopter will be a hand- directed tuned pnotoelectric receiver of sensitivity such that for the distance worked, full scale on tne recorder attached to the receiver will correspond to 100 per cent transmission for the air path between tne source and the receiver. The helicopter will fly at tie same altitude as tnat planned for the burst and will be used for this type of measurement eacu day in tne period from minus 20 days before tne King Shot until the day ofthe shot. The importance of the total thermal measurenenta at King Shot has justified an expansion of the thermocouple program, and it is now planned to operate four thermocouples at Biijiri, four at Aniyaanii, and four at Parry. At Biijiri and Aniyaanii, two separate power systems will be used: the local power to be supplied by Holmes & Narver, and a battery-powered motor generator started on the <2 min timing signal. Eacn of these two types of power supply will drive the records for two thermocouples, one recorder being a General Electric photoelectric galvanometer and the other a leeds and Northrop recording potentiometer.