of the skirt at 1.5 minutes and the latest measurement at 10 minutes. Figure 6.14 is an excellent example of the appearance and multiplicity of skirts visible on this and other shots. 6.5 SHOT 6 . , | Because of natural cloud cover, no measurements of the subsidiary features of the cloud from this shot were possible. 6.6 CLOUD DIMENSIONS AT HIGH ALTITUDES It was possible to make some rough approximations of the cloud and stem dimensions of the Castle shots at altitudes of 35,000 and 50,000 feet at times up to 45 minutes. The figures presented in Tablé 6.1 are only approximate, because of uncertainties in aircraft ~* | —- positions at ‘such late times. It is felt, however, that this information may be of assistance in estimating hazards to which personnel of a sampling aircraft might be subjected in penetrating the cloud or stemafter a detonation. 37 SECRET tne ne eh epee mee tte ume et Oe sorte ee — am wee ee hae