ee ee, 2. WHAT IS THE EFPICIENCY OF THE GUMMED PAPERS IN SEPARATING resrotare FROM RAIN? Suspensions of radioactive iron were prepared in the lab~ oratory and artificial rain produced under various conditions of temperature, The effectiveness of the gammed papers in sepa~ rating the iron particles from the "rain" was determined, 3. Principal Findings Retention at 1" rainfeil ver hour v ried from 50% of all partiof all particles less than 2 p to l cles less than 2 Data for less evere rainfall rates are not as yet available av Method of Study TO WHAT EXTENT IS THERE VARIABILITY IN THE FRACTIONS OF srf IN BOMB DEBRIS? Method of Study AND 5r70 Principal Findings Samples of fallout am atmospheric dust from various bursts were Fallout during the weeks immediately a burst is deficient in both strontiuh Samples of both fallout and airborne ity and the two isotopes of Sr. to have been the principal contributog, are enriched in both isotopes. analyzed for total activ~ following isotopes, @ust collected towards the end of 1953, at which tim@ MIKE appears | In some samples the measured sr89-90 theoretical by an order of magnitude, cases by less than a factor of two, viated from ut in most