° 4:4 /[ 2, | 89 ° 8» Ke; } 6 \ 37 33 \ NN oO 2-0 o 2:9 Oo Oo 5 41 I FIG. 12. 10 N °o o 4:4 V7 | _ 10 100 o ra 0 3-0 0 89 oO 1-6 4-2 . Lien IG@E O 55 13 / O 3-2 \ ) 21 oO ™ 22 >\ ©} 37 \ sO 25 . 3 / o 33 j | 4°) _ ‘. 9“20 ~ oO “Gay | 4-0 “ NL / 4-2 , 2 6 oO . .° ‘ WOTHO 3:5 LON I66 E RADIOACTIVITY OF SURFACE WATER IN THOUSANDS OF DISINTEGRATIONS PER MINUTE PER LITER