92 



Both during the season and on the post-season cruise the thermom- 

 eters, which were used in pairs, were occasionally shifted with respect 

 to each other so that each thermometer was eventually paired with 

 several other thermometers, thus furnishing a check against the 

 possibility of any thermometer or thermometers suffering a change of 

 calibration or ceasing to function properly during the period of obser- 

 vations. A total of 2,024 such comparisons were investigated. 

 Probable differences between the corrected readings of the pair of 

 thermometers were computed for each group. These probable dif- 

 ferences varied between 0.003° and 0.019° C. and the probable differ- 

 ence for the entire 2,024 comparisons was 0.008° C. It is therefore 

 considered that the observed temperatures are accurate to 0.01° C. 



The current maps prepared during the season were made following 

 the procedure used in 1934, the season's maps being referred to the 

 1,000- decibar surface. The current map representing conditions 

 found on the post-season cruise is referred to the 1,500- decibar surface. 



From the current map for April, figure 19, it will be noted that the 

 Labrador Current was flowing very swiftly along the eastern edge of 

 the Grand Banks, especially in about latitude 45° N. However, it 

 apparently did not bend westward of about longitude 50° W. at the 

 tail of the Banks. The southeastern edge of the map indicates a gen- 

 eral northeasterly direction of drift for the bergs which were earlier 

 reported in this vicinity. It will be noted that although figure 19 

 has been drawn with continuous isobaths, the southeastern edge, in 

 about latitude 44° N., might possibly have been drawn with a pool of 

 low dynamic height in this position. In the absence of more closely 

 spaced oceanographic stations it is conjectural which interpretation 

 should be chosen. The choice shown in figure 19 is the one which 

 was made at sea on April 21 when the map was originally prepared 

 for immediate delivery to the cutter on patrol. Judging from the 

 sea-water surface thermograph records, the cold wall had moved 

 northwestward about 20 miles in the vicinity of Flemish Cap during 

 the interval between March 30 and April 19. 



Referring to the current chart for May, figure 20, an outstanding 

 feature is the presence and strength of the Gulf Stream in the south- 

 eastern portion of the map. This northward encroachment is also 

 indicated by the more rapid current in the vicinity of the longitude 

 of 50° W., south of the tail of the banks. The irregular current pat- 

 tern shown along the southeastern edge of the April map has developed 

 into a broad intrusion of Gulf Stream water, seen in the middle eastern 

 portion of the May map. The two salients of this intrusion, in about 

 latitudes 43°30' N. and 45°30' N., are traceable from the previously 

 mentioned irregularities shown in the April map. The Labrador 

 Current is still strong in about latitude 45° N., but its intensity is 



