lO 



BJØRN HELLAND-HANSEN AND FRIDTJOF NANSEN. 



M.-N. Kl. 



2770 27 60 



Fig. 13. Curves of Density (at) for Stats. 25—28 (Sect. IV). the densities of the up- 



27-^0 per parts of the curves 

 '^ of June have to be re- 

 duced in order to give 

 the curves probable 

 shapes. Taking the sa- 

 linities to be fairly correct, it is then possible 

 to determine how much the temperature-read- 

 ings of the Nansen-thermometer have to be 

 raised in order to give the probable densi- 

 ties thus found. 



The observations of the temperatures of 

 the sea-surface were made with a special 

 thermometer which was immersed in the water 

 taken from the sea-surface with an ordinary 

 bucket. Provided that these observations have 

 been fairly correct and that the salinities found are 

 trustworthy, the densities of the surface-water give a 

 limit below which the densities of the underlying 

 strata may not be reduced by the raising of the tem- 

 peratures taken with the Nansen-thermometer, not 

 considering small irregularities that may arise from 

 in accuracies of the observations, and also from the 

 movements of the ship and the water, as the surface- 

 observations being not always taken exactly on the 

 same spot or in the same hour as the observations 

 of the water at 20 metres. 



In this manner the surface-observations afford a 

 possibility of finding a probable upper limit of the 

 correction of the readings of the Nansen-thermometer 

 in June, 1910, while the observations with the revers- 

 ing thermometer, combined with the salinities, give 

 the lower limit of the same correction. By taking the 

 means of the values thus found at each station, we have come 

 to the conclusion that the readings of the Nansen-thermometer 

 should be corrected by about -h 0.80 C. at all stations of June 

 25th to 28th (/. e. Stats. 1 — 14). When the readings have been 

 thus corrected we obtain very probable values both of tempera- 

 ture and density. 



That the vertical temperature-curves thus obtained have very 



2000^ 



