0018933 to disperse the particles, Traverses were made along the slide from one extreme edge of the dispersion to the other and every particle within the micrometer scale was sized and typed, spaced traverses were taken, Generally, several appropriately The particles were sized in terms of mazd- mum diameter and typed by the conventional classification of irregular, spherical and agglomerated, Diameters were measured to the nearest one-half scale division and particles less than a half unit were ignored, Particles adhering to each other were sized individually, if possible, or otherwise not taken into account, Particle characteristics, fall-rate and size distribution curves are given in Appendix C. No particle work was done on the samples from Oak and Walnut, 2.5 SAMPLE ANALYSIS AND RADIOCHEMICAL PROCEDURES Radiochemical analyses were carried out on the gross particulate cloud samples from the wing tank collectors, on size-separated cloud samples, on the gas-particulate samples from the coincident units and on | the fallout samples. The major part of the analytical work on the cloud and fallout particle samples was done by NRDL (some by LASL), while the gasperticle samples for the determination of fission ratios (Section 1.2, 4) were analyzed at UCRL,