230 H. Hansen. 
which from September 1909 to July 1910 were observed after the scale 
0—4, is here reduced to the international scale (0—10). 
For figuring out the mean temperature, the following formula has 
as a rule been used: 
2 (8a + 2p) + 5 (9p) 
9 
In the cases, where observations are made at other hours than 
the customary ones, or have been incomplete, other combinations are used. 
In Table 6 a comparison is made of the monthly means of ob- 
servations as to the pressure of the atmosphere and the temperatures 
of the air from North-east Greenland — Danmarks Havn, Shannon 
Island and Bass Rock — covering a span of years from 1906—1912. 
For the months from January to July, as well as for December 
we have now observations from these localities for 5 years, for August 
in 3 years and for the months September—November in 4 years. 
It must however be remarked, that the figures for August 1906, 
July 1908, December 1910 and July 1912 are calculated on basis of ob- 
servations in respectively 15, 21, 20 and 17 days, and furthermore, 
that the mean of the pressure of the atmosphere for the month of 
March to May 1912 are based on respectively 20, 14 and 18 days, and 
at last, that the mean temperatures for the months of January to March 
1912 are somewhat uncertain, as some rather low temperatures are in- 
cluded in this material, which temperatures cannot be determinated 
with certainty by means of a mercurial thermometer. 
