0.4 a0. 70 10} 190 500 72 440 270 92 8] \ CyesSS Ae 200 2224 ZA 102 100 °389 . ° Wi 650 357 140 300 200 100 240 670 150 7.8 oN 178 237 ; 31 21 54 Ll) 0 10 20 MILES Fig. 5—Isointensity contours for 20- to 50-u particle diameters in milliroentgens per houy at 1 hr. WVHDOUd HOYUVAESAY LNOTIVA LOHS AO TTVWS 50 $9 20