57° 56° 55° 54' 



59° 58° 57° 56° 55° 54° " 53° 52° 5° 50° 49° 48° 47° 46° 45° 44° 43° 



Fioi'RE 12.— Fourth cruise, April 25 to May 9, 1939, showing surface isotherms, tracli of Kssel, and ice conditions. (Numerals indicate day of month ice was si:,'hted or reported.) 



220899—40 (Face p. 34) Xo. 4 



