SESSION VII 371 DUNITAM: [dunt know, Do we have any experience other than with coral fluff which anparently is quite readily visible even to the Rongerik people? EISENBUD: Well, Chuck, if it's going to doa lot of harm, it has to fall out, DUNHAM: Eventually fall, FISENBUD: It has to fall out within a few hours. In order to fall out within a few hours, the particles would have to be-greater than about 23 or 39 microns and they would have to exist in large enough numbers so that [think you could see them, DUNHAM: EISENBUD: DUNHAM: EISENBUD: Is this tmpcortant’ Yes, - Better than a reading” No, [ don't think it is because a fallout wont be white and this is somcthing that buthers me. WARREN: You're thinking of 109 miles away where you can't see the column, are you not? BRUES: You can see the burst, WARREN: Because a column, in general, would hase some morsture in it. EISENBUS)- You can’t always see the column anyway, Staff. [mean it could be a cloudy day and you would have lots of dust kicked up. -You see, we have exploded these things under rather unusual cireum- stances necessitated by the fact that they are tests, Creer the desert you don't have the conflagration that-you would have in a large builtup area, You knowbetter than I what Hiroshima looked lke just a short while after the fire. 1 don't think you couid sce the column very far away particularly if it was in the superton range, but vou're yoing to have fallout because you have fallout, not radioactive fallout. Every fire produces fallout cf carbon some distance away. [ve seen it in New York City from forest fires up in Canada. This could affect the