59° 58° 57° 56° 55° 54° 53' 



59° 58° 57° 56° 55° 54° 53° 52° 51° 50° 49° 48° 47° 46° 45° 44° 43° 



Figure 6. — Ice conditions, May 1951, and surface isotherms for the period 1-13 May 1951. 



204964 0—53 (Face p. 8) No. 6 



