17 fortuitous since the available Sr?) in the soils, that fraction extractable into normal neutral ammonium acetate, is somewhat less than the total, From Picture 3 it is clear thet most of the fallout has becn deposited since the begirning of 1953, The change in average annual slope indicates at least qralitatively the increasing annual contribution of stratosoheric debris to total fallcvt. The general agreemnt between the change in goil level md eumletive fallout in rains during the intervening neriod is graphic indication that the scavenging of the atmosphere by rains is the primary mechanism of fellout, Sampling of rains iith tubs continuously exosed vill include collec- tion of dry fallout of large particles vhich may be appreciable for considerable disteices dovmvind of test areas during the first few days following an atomic teste NYOO