A. C. Graves 6 June 28, 1951 the yield is 1 KT and ths total activity at the end of 1 hour is 300 megacurics, A deposition of 1 megacuric/mi¢ is equivalent to lh r/hr. A few remarks should be made in amplification and support of these assumptions. ‘The assumotion of constant wind velocity is better suited to work in the U. 5. than to work at Eniwetok. Also, for the JANGLE shots, the clouds ere not cxpectcd to rise to the great heights at which pronounced wind shears arc found, ‘he assumption of a spreading of the cloud corresponds to the observation that clouds do spread, but no detailed mechanism has been included in the calculations, Stoke's Law is used in the absence of anything better and in the knowledge gaincd from Miwetok that it gives results not too far out of Tine with the facts. Similerly from expcriments, all of which were above ground, it is clear thet the higher parts of the cloud are more active than the lower (this fact may not hold for subsurface bursts), ‘the choice of the 7/2 power law increase with height is, of course, arbitrary, and was made in order to obtain a hot spot like that found at Trinity. ‘he odd half intcgral power was chosen to simplify the integrations. Stoke's Law rclating the height from which a particle of given diameter must come in ordcr to reach the earth at a given time indicates hs KD“. In the integration of height and pirticle size which determines the activity at a given distance, one thcreby obtains an odd power of x in the integral x f 0 \ 2 \ «hen # 1) ox dx 0 i and can obtain the answer without reduction of the intcgrel to a sum of terms plus an intcgral o” the form x 0 2 e* dx /° Tie choice of a particle size distribution function is likewise arbitrary and is justified on scveral grounds. A Gaussian distribution is perhaps more logical but is equally arbitrary, implies some particles of negative diametcr, and introduces an additional parameter, the standard deviation. The fact that the function chosen DO ARCHIVES ©