KFULOGOs (continued) which I have indicated there, taking inte account dec would be in the order of 400,000ion pairs per cubic centineber per second in one day, | VOICEs Fhat tics elexant? ESLLOGGs One day having expended so that the voluns, this is ha average in the cloud, has expanded dus to this kind ef diffusian. At the end of two days, three days, four dsys, it will ef box decay further and would-—I have not made the caloulstion as te when it would cet down to the level of cossio rays, I Shége it would be sonething in the order of a week before 1¢ ot € get down in the center of such a cloud to anywhere approaching the = ecoscic-ray ion production. This is one thing which had|te be estizated first. I don't think this estimate is a very curate one, but it does suggest that one coald use ‘tee pads Soom sa ° tivity to track the cloud for at least a matter of days. The idea ef finding where the cloud goes in the stratoagher isa vary attractive one, because I think it is largely a ether of conjecture now as tc how vertissl diffusion does takepi .0 in the stratosphere. I agree with E. Yexler in inazining ¢ ‘ 4% would be very slow, Yertioal diffusion in the upper pars of | the stratosphere certainly would be very slows Re have sane evidence, though, that suggests that vertiog diffusion in ths lower part of the stratosphere, which stable, is rather high. alse This is based on observations of ssoke — Post Inargy sam aw we