4 oO m= ft x w ~ So A + CO al = E a\2 pore y ONT < | aT a Oo T Ol] 4 Oo 1 & Rh’? CONCENTRATIONS ABOVE 19.5 km DURING FIRST HALF OF 1959 4 Oo 709 © |-59 x 3-59 A 4-59 O 5-59 + 6-59 ! 60 50 1 40 SOUTH L 30 l 20 i lO L OQ E i iO , 20 4 30 40 NORTH Ld 50 Fig, 3 -- Concentration as a function of latitude during first half of 1959 %2 60 70