The nature and quality of portions of the Marine Deck of sea-surface temperature (SST) records for Marsden Squares 114 and 78 (20°-40°N, 50°-60°W) have been examined to determine their suitability for historical analysis of SST, and for evidence of climatic variation. Apparently the data is numerous enough to demonstrate, using six-year means for individual months, a warming from 1910-1920 to a maximum in 1950-1960, and thereafter a cooling, coherent over both square (both in winter and summer), trends consistent with other sources of data.