been lost below the thermocline for the fast-settling fraction of solid-particle fallout. Fractionation of radionuclides from Shot Zuni was severe while that from Shot Tewa was moderate; Shots Flathead and Navajo were nearly unfractionated. Tables are provided, incorporating fractionation corrections where necessary, which allow the ready calculation of infinitefield ionization rates, and the contribution of individual induced activities to the total ionization rate, Best estimates are given of the amount of activity deposited per unit area at all sampling stations. Estimates of accuracy are included for the major stations.