data was completed at station 6036 on the evening of 18 July with the 

 omission of only the last of the planned stations. The Evergreen then 

 proceeded to Woods Hole, stopping briefly at Argentia on 22 July to 

 pick up spare oceanographic equipment stored there during the season. 

 Woods Hole was reached on 25 July and oceanogi-aphic equipment and 

 personnel were off-loaded to complete the oceanographic field work for 

 1955. During the post-season cruise 53 stations were cocupied. 



The oceanogTaphic work was under the supervision of Oceanog- 

 rapher Floyd AI. Soule who was assisted by LT John E. Murray. 

 During the third survey LCDR Harry H. Carter also assisted. Other 

 assistants in the observational work were Francis N. Brown, yeoman 

 first class; Elwood C. Gray, aerographer's mate first class; Lewis M. 

 Lawclay, aerographer's mate second class; Hugh R. McCartney Jr., 

 aerographer's mate second class; and Bruce M. McCluskey, boat- 

 swain's mate third class. 



Of the 296 stations occupied during the season and post-season 

 surveys the 23 stations forming the section across the Labrador Sea 

 were occupied from the surface to as near bottom as was practicable, 

 and at the other 273 stations the observations extended to a depth of 

 about 1500 meters where the depth of water permitted. As in pre- 

 vious years, the intended depths of observation, in meters, were 

 0, 25, 50, 75, 100, 150, 200, 300, 400, 600, 800, 1000 and thence by 

 500-meter intervals. The dynamic heights have been referred to the 

 lOOO-decibar surface, except for the section across the Labrador Sea 

 where the 1500-decibar surface has been used for reference. 



In addition to the usual measurements of temperature and salinity 

 264 samples were taken during the occupation of the South Wolf 

 Island-Cape Farewell section for subsequent determination of total 

 phosphorus concentration. 



Temperatures were measured with deep-sea reversing thermometers. 

 Most of the protected thermometers used were of Richter and Wiese 

 manufacture but a small percentage were made by Negi'etti and 

 Zambra, G. M. Manufacturing Co., and the Kahl Scientific Instru- 

 ment Corp. The depths of observation were based on unprotected 

 thermometers made by Richter and Wiese and by Kahl. As de- 

 scribed in earlier bulletins of this series a progi'am of intercomparison 

 of the protected thermometers was carried out. From a total of 

 1994 comparisons, the probable difference between the corrected 

 readings of a pah- of thermometers was 0.010° C. As many of the 

 thermometers had recent laboratory comparisons with thermom- 

 eters tested by the National Bureau of Standards, and as in most 

 cases the temperatures are the means of the corrected readings of a 

 pair of thermometers, it is considered that the observed temperatures 

 listed in the table of oceanographic data have a probable error of 

 about ±0.01° C. 



62 



