2e2 COLLECTION OF SAMPLES The fallout samples were collected at stations established by the personnel of Projects 2,5a and 6.4. The location of these stations and details of the collectors used are given in the reports of Projects 2.58 and behe . Chemical and radiochemical studies were made on samples from Shots 1,2,3, and 4. Limited radiochemical measurements were made on samples from Shots 5 and 6, Physical data on the nature of the fallout were obtained from Shots 1,2,4, and 5. 2.3 EQUIPMENT The analyses at the site were rerformed in mobile laboratories budlt in trailers. These laboratories were equipped with conventional chemical apparatus and several tyres of special apparatus as well as beta and gamma counters, A gamma spectrometer was located in an air conditioned building near the mobile Bboratories. The equipment at USNRDL consisted of conventional apparatus for chemical, radiochemical, and physical studies as well as several special types of apparatus. Included in the conventional equipment were bsta and gemma counters, an emission spectrogr_oh, spectrophotometers, X-ray diffraction apparatus, a petrographic microscope, a crystalab ultra- sonorator, Model SL 520, Beckman pH meters, ion-exchange columns with accessory equipment, and the standard apparatus found in chemical laboratories. The special equipment included aerosol sampling devices and film coating, developing, and scanning apparatus, 2e3el Sample Collectors Samplers of two types were used fcr collecting fallout for chemical and radiochemical studies, Also, some of the samples from Project 2.5a collectors were studied on this project. One type of collector consisted of three legal polyethylene bottles fitted with 7-in. diameter fumnels of the same material mounted in a frame with a mechanical device arranged to uncover the three funnels at detonation time and cover them again after 3 hr. These samplers did not operate originally as well as had been anticipated but after sone modification operated satisfactorily. The other type of collector was a collecting funnel 6-1/2 ft x 11 ft built onto a life raft and arranged to drain into a 13-gal polyethylene bottle, Because this apparatus was inadequately designed and constructed to cope with conditions found in the field only a limited number of samples were obtained from it. 2.302 Counters The beta detectors were NRDL Model PC-l proportional counters. coaxial anode type, These detectors were of the cylindrical, side-window, 20