FRIDTJOF NANSEN. M,-N. Kl. 



Except at the first few stations, several water-bottles were alwa3-s used 

 on one line attached at ditïerent depths. B}' using the Pettersson-N.\xse.\ 

 water-bottle at the end of the line, and the Ekman reversing water-bottle, 

 the two stop-cock water-bottles, and the reversing stop-cock water-bottle 

 attached to the side of the line, we were able to take the temperatures 

 and water samples from as many as 5 different depths in the same haul. 



The Temperatures. The temperature of the sea-surface was taken 

 with a water bucket (marked B in the Tables) and an ordinary thermo- 

 meter, and water-samples were taken simultaneously. 



The temperature of the sea-water at the different depths was as a 

 rule determined by the Richter reversing thermometer, and two thermo- 

 meters were often used simultaneously at the same depth. Sometimes the 

 temperature was also taken b}^ the Pettersson-Nansen insulating water- 

 bottle, and the Nansen deep-sea thermometer; but the readings of the 

 latter were as a rule checked by the Richter reversing thermometer. At 

 the first five stations where the depth did not exceed 150 metres, the 

 temperatures were taken with the new automatic, insulating water-bottle and 

 an ordinary thermometer. 



All thermometers were old instruments, which had been carefully tested. 

 Most of them were the same thermometers that had been used during the 

 cruise with the "Frithjof" in 1910. All readings of the thermometers, except 

 those of the sea-surface, were taken by myself, with a reading lense. The 

 readings of the reversing thermometers have been corrected for the instru- 

 mental error, the error of freezing-point, and the error caused by the 

 temperature at which the thermometer was read off^ The thermometer- 

 readings of the insulating water-bottles have been corrected for the instru- 

 mental error of the thermometer, as well as the error caused by the 

 adiabatic cooling. 



The accuracy of the values of temperature obtained by the 

 reversing thermometers ma}' be expected to lie within ± o.oi " C. 



On some occasions the second thermometer (No. P.T. R. 375 47) of the 

 Ekman Reversing Water-bottle (E) suddenly registered irregularly. During 

 the first part of the cruise its readings agreed very well with those of the 

 other thermometer (No. P.T.R. 375 46) of the same water-bottle, except once, 

 on August 4th (Stat. 19 d, at 80 metres), when it gave— 0.64" C. instead 

 of — 0.82OC. But suddenly on August loth (Stat. 27) it gave — 0.61 ^C. 

 and — 086OC. instead of i.7i"C. ando.78*'C. During August loth, nth, 

 and 13th, the thermometer continued to give too low readings (between 

 — 052^0. and — 1.72OC.) except at 100 metres, at Stat. 29, where its 

 value of temperature I — 0.12" C.) agreed perfectly with that of the first ther- 



