Floyd 1, was in the topmost layers of the cloud at 55,000 feet absolute altitude and had to come down several thousand feet to conduct sampling. A private communication from Jere Knight indicates that the topmost section of the cloud had a calcium eeeeee LL waeed aaence naman to fission ratio approximately 1% of that at lower altitudes. A picture of the cloud taken from the control air- plane soon after shot time is shown in Fig. 11.2-1 lying above the cirrus cover. In the original print dark portions suggest that a considerable portion of the cloud lay below the cirrus in the natural weather existing up to 37 - 38 thousand feet. Figs. 11.2-2 and 11.2-3 show the cloud at later times after burst when the wind shear effects can be seen from upwind and cross-wind views respectively. The long streamer seen in Fig. 11.2-3 4s the result of a wind velocity at 55,000 feet (absolute) which 1s approximately 17 knots slower than at the cirrus level and is an illustration that negative as well as positive velocity shear can produce the same relative effects. A dimensional analysis of this photograph shows that the length of the streamer is commensurate with this velocity shear. A notable characteristic of this cloud was that the radiation intensities observed were a factor of from five to nine lower than for previous clouds at the same altitudes and times after burste Copled/DOE LANL, J-Div, .