a Ps (Continued) the type of scavenging you would have to deal with. 1 scavenging would ‘occur only for particles larger than s microns. If we were down in this range, less than .01:, would get fairly high average efficiency and would bring [this staff down, but hers, between 0.1 and li, unless we can with some rew mechanisn for bringing it down, we vould Little scaversed cut. We vent on and calculated again far have very 1? being diluted, enough additional material had been b into this rain-dbearing level so that the deposition on was about twice what we got in six howrs. The caloeclati 2 hours shows that the deporition began to get sraller, estimate the harard has been going on for a ecuple of years now and I think we are still quite fer from a reasonable model that we might like to try to test on what little available. dite is I think, for one thing, we must take into acdcunt scme better law of diffusion. ‘be ure what ies available ow, we know thet thie doesn't give ue a good pictare ef diffusi the atacephere and Mr. Edinger will epeax more full on afterncen. tat this We need scae batter law for diffusing this coud. Another point, we need sore more experimentally deterningd values of whatever constants might enter into whatever diffusiod we need. Departesct 9° His r . py Another point, we have to be able to consider . laws