8 H. MOHN. METEOROLOGY. [NORW. POL. EXP. 



After the voyage, 86 observations at the Institute gave 

 Att. Therm. Corr. Obs. 



- 2-7 + 0-105 mm. 21 



2-0 + 009 31 



18-8 - 0-19 28 



25-6 - 019 6 



This gives, 



for 1893, Corr. = - 0"015 0-031$ 9 25) = + 0'271 0'031 . t 

 1897, = - 0-018 0-017 (t - - 9-3) = + 140 0-017 . t 

 Giving double weight for 1897, we get 



Mean Corr. = + 0'18 0'022 . t mm., 

 which I have adopted. 



In the same manner as with Adie 763, I have deduced the influence of 

 pressure upon the correction. 



t b Corr. 



- 3-7 771-7 mm. + 0'06 mm. 



- 3-0 743-1 + 0-10 



18-1 768-1 - 0-08 



18-5 741-5 - 0-03 



Corr. (1897) = + 0140 0'017 t + 0'0007 {760 - 6). rnm. 

 6 = 730 ; 0-0007 (760 6) = + 0'02 mm. 

 6 = 780 0-0007 (760 6) = O'Ol mm. 



On board ship, Adie 763 and Adie 76 1 were compared from February, 

 1895, to June, 1896. 



No. 764 No. 763 Temperature 

 1st Half-year, 1895 0'26 mm. 164 



2nd 1895 0'27 16"2 



1st 1896 0-22 15-9 



Mean 0'25 mm. 16'2 



The adopted corrections are, at 16-2, 



For Adie 763 Corr. = + 0'12 mm. 

 764 - 0-17 mm. 



Difference 0'29 mm. 



Diff. observed on board 0'25 mm. 

 Difference 0'04 mm. 



