Sy 58° ^'^ ^T , ^.^° -^ .^1^^— r-,=^i|^-^-^ ^^^^-^-i-^^°^3-TrT 



50° 



47° 



46° 45^ 44° 43° 



59° 58° 57' 56° 55° Fi4° 1=;^° >;oo rio r^o ^.q' 48° 47° 46° 45° 44° 43° 



Figure 4.— Surface isotherms for the period 1-15 April 1951. No ice was sighted or reported within the limits of this chart during the period. 



204964 O— 53 (Face p. 8) No. 4 



