The scatter of these points from the curve was considered to be fortuitous 

 and the curve acceptable. The uncertainty of ± 0.023%o is beheved to 

 be largely attributable to the titration measurements, since the precision 

 of the bridge measurements is much better. 



During each routine salinity run the bridge was standardized with 

 water from the oil-sealed carboy of substandard water, using the tentative 

 value of the dial reading corresponding to the substandard and standardiz- 

 ing about every 10th to 13th sample in each of the cells. At least once 

 and usually twice during a run Copenhagen standard water was measured 

 as an unknown. From these measurements of Copenhagen water the 

 tentative value of the X-dial reading corresponding to the standard water 

 was corrected for each surve3\ The initial carboy collected earl}' in April 

 was used during the April, May, and June surveys and on the post-season 

 cruise through station 3715. The corrections, expressed in terms of 

 salinity, were negligible for the April and May surveys and amounted to 

 0.01%o for the June survey and post-season cruise through station 3715. 

 For the remainder of the post-season cruise, Copenhagen standard water 

 was used directly for standardizing the bridge. The tables show the 

 corrected values of salinity. However, as the dynamic heights had al- 

 ready been computed and the topography delineated, the values of at 

 have not been recomputed but a flat correction of 0.01 applied. Like- 

 wise the tabulated dynamic heights have been decreased by 10 mm. 

 where they are referred to the 1,000-decibar surface and by 14 mm. 

 where 1,500 decibars is the reference surface. The dynamic topographic 

 chart resulting from the June survey' has not been corrected and hence 

 shows topography which is 10 dynamic millimeters too high. 



The oceanographic work was under the supervision of Oceanographer 

 Floyd M. Soule assisted b}' Lt. (jg) Harry H. Carter during the season, 

 and by Lt. Leroy A. Cheney during the post-season cruise. Calibration 

 titrations were by the Woods Hole Oceanographic Institution and by 

 Christopher R. Murray, yeoman, first class. Routine salinity bridge 

 measurements were made by William B. Arndt, aerographer's mate, 

 third class, and James F. Cizek, aerographer's mate, second class. Other 

 assistants in the observational work were David H. Koch, aerographer's 

 mate, third class, during the April and May surveys; Richard L. George, 

 seaman first class, during the June survey; and Charles J. Albanese, chief 

 quartermaster, during the post-season cruise. 



The dynamic topographic chart resulting from the April survey is 

 shown in figure 17. This survey showed the southwestern slope of the 

 Grand Banks to be dominated by mixed water and slope water of the 

 Gulf Stream system moving in from the south. The whorl centered near 

 the eastern edge of the charted area at about 42°20' N., showed a mixed 

 layer about 200 meters in thickness with a temperature of about 12°.8 C. 

 The area was completely free of true Labrador Current water, the lowest 

 observed temperature being — 0°.28 C. From the course of the dynamic 

 isobaths there seemed little likelihood of the currents providing trans- 



73 



