170 I. P. Косн. 
well as at an altitude of 200 and 500 metres”) the temperature of 
the altitudes of 180 m (the sighting point on Cairn IX) and 429 m 
(the sighting point on Cairn X) was determined by simple inter- 
polation. In case t,,, Бо, {200 and t,99 indicate the temperatures 
in centigrade at the Observatory, as well as in the altitudes 180 m, 
200 m and 429 m, Tıx was estimated at 273° + 1/2 (t,, + Ы во) whereas 
Tx on account of the boundary between the strata at 200 m was 
computed from Tx = 273 + Ча (В, +2,50 + 1429): With corre- 
spondent designation we had ax = (t,59 — 1,4): 166 and сх — (42° 
—t,,):415. The atmospherical pressures byg and by were computed 
by means of the pressure of the air, b,, at the level of the sea and 
reduced to 0°2), by using the simple formula for barometrical mea- 
surement of altitudes 
В — 18400 (1+ at) log 2 
in other words without making allowance for the terms of correction 
of the pressure of aqueous vapour, the geographical latitude and the 
mean altitude*). As an example may be quoted that for the sight 
at Cairn IX are get: 
2 
As absolute determinations of k have not been made between 
the Observatory and Cairn IX, I have from the mean value for x 
and the single values formed 4x = x--xm, and for comparison 
I have in the table below given 4k with the same value as in the 
table p. 157. Seeing that 4x, as it will appear, only refers to a 
mean value of ten single values, whereas Jk is formed by com- 
parison with the mean of all fifty-three determinations, the juxta- 
position of 4x and Ak in the table is not strictly logical. The cor- 
rection which should have been applied on the 4k’s in order to 
remedy this drawback is, however, only + 0.003, which quantity, as 
a glance at the table will show, is of no importance to the direct 
comparison. 
1) See: ALFRED WEGENER: Drachen- und Fesselballonaufstiege; Danmark-Ekspedi- 
tionen til Grønlands Nordostkyst 1906—1908, Medd. om Grønland Bd. XLII. 
2) See: ALFRED WEGENER: Meteorologische Terminbeobachtungen am Danmarks 
Havn; Medd. om Grønland Bd. XLII. 
The complete formula is as follows: 
3 
e 
b 
h, +h, = 18400 log $" (1 + at) (1 + 0.377 >) (1 + 0.000265 cos2e) (1 Е 
h, +he 
в | 
е 
where b is the proportion between pressure of vapour and pressure of air as 
mean value in the column of air considered; ¢ is the mean temperature in centi- 
grade and R the radius of curvature. 
