6 



Table 1. 



OBSERVATIONS AND RESULTS IN PHYSICAL OCEANOGRAPHY 



Thermometers used on the Carnegie, cruise VII 



Fabr. 

 no. 



PTR no. 



Date of 

 PTR 

 cert. 



Grad- 

 uation 



Range 



Used at 

 stations 



1927 



Table 1. Thermometers used on the Carnegie, 

 cruise VII --Continued 



Fabr. 

 no. 



PTR no. 



Date of 

 PTR 

 cert. 



Grad- 

 uation 



Range 



Used at 

 stations 



1929 



*Lost at station 32. bLost at station 151. 



c- Lost at station 49. ^Lost at station 156. ^Lost 



at station 144. 



and 0°8), perhaps owing to the opening of a bubble in the 

 glass. BOhnecke states that the amplitude of the change 

 of the zero point amounts on the average in the case of 

 the one-twentieth thermometers to 0.°015 and in case of 

 the one-tenth thermometers to 0.°02, the corresponding 

 maximum values being 0.°035 and 0.°08. In this connec- 

 tion it may be mentioned that the corrections at zero 

 scale division of the fifteen reversing thermometers 

 used on the Maud expedition were determined at the 

 Reichsanstalt in 1909, 1910, or 1914. The redetermina- 

 tions made in 1922 to 1924 showed these corrections had 

 remained unchanged in eight cases, had increased by 

 OfOl in two cases, had decreased by 0.°01 in four cases, 

 and by 0.°03 in one case, the mean change being ■0.°003 

 and the maximum -0?03. These results cannot be com- 

 pared with the results of the Meteor expedition because 

 the small changes of the Maud thermometers may be 

 ascribed to the circumstance that the PTR calibration 

 had taken place a considerable time after the completion 

 of the thermometers by the manufacturer. In the case of 

 the Carnegie thermometers, the possibility exists that 

 the changes in the zero point may reach the amounts 

 which Bohnecke found for the Meteor thermometers. 

 Any considerable change of the zero point of one ther- 

 mometer, however, can be detected if this thermometer 

 had been used together with others and examinations of 

 the differences between thermometers which were used 

 in pairs should give valuable information. On the basis 

 of experience on the Meteor it must be expected further- 

 more that thermometers received in 1929 would show 

 slightly lower temperatures that those received in 1928, 

 because it must be assumed that the zero point has risen 

 more for the older thermometers. It must also be ex- 

 pected that the temperatures based on the original PTR 

 corrections on the whole will be slightly too high because 

 of the rise of the zero point but the mean error due to 

 this circumstance will hardly exceed 0.°02. 



