PRESENT STATE OF OUR KNOWLEDGE OF THE UPPER ATMOSPHERE. 119 
and therefore also ¢, and 8 p diminished above a height of 8 km. Of course, 
as long as 8 T remains positive 5 p/p will increase, and therefore V will 
increase. But the results for temperature show that 6 T is positive up 
to 10 km., after which it becomes negative. The observations of tem- 
perature and wind are therefore in general agreement, indicating an 
increase in V p up to 8 km. and an increase in V up to 10 km., with a 
tapid decrease of both at greater heights. 
The direction of the upper wind usually veers from that at the surface, 
t.e., if the wind is W. at the surface, the upper wind comes from some 
point N. of W. This is partly due to the fact that surface friction opposing 
the motion makes the steady state one in which the direction of the wind 
is between that of the gradient and the isobars. The smaller the friction, 
the closer does the direction for the steady state approach that of the 
isobars. 
The following values for the rotation of the upper wind from that at the 
surface are deduced from Berson’s results :— 
Height . : ait, £085, 1 15 2 2°5 3 4 5km, 
Rotation a R $2 15° 216 28° 35° 39° 40° 43° 
No. of Cases «os 58 58 51 43 39 35 22 
In comparing these results with those obtained from kites it is to be 
remembered that a balloon does not rise vertically, but is carried along by 
the moving air and partakes of any natural curvature of path this may 
have in its horizontal progress. 
Similar results found by White, Pring and Petavel' show a smaller 
increase between 1 and 1°5 km., after which the increase is rapid. 
Height . : : 0:5 1 15 2 2°5 km. 
Rotation : : ie 18° 20° 30° 40° 
The authors do not state if these results are the mean values of the 
rotation irrespective of sign or not. 
The following values have been found for the deviation up to 3 km. 
from the observations made in England in 1906-07-08.” The values are the 
means of the individual cases, rotation in a clockwise direction (veering) 
being counted+. The values are arranged according to the direction of 
the surface wind, 8.W. winds being counted W. and so on. Only those 
observations are used in which the wind at 1,000 m. was not less than 
5 m.p.s. The values of R are the angles made by the upper wind with the 
surface wind. : 
Deviation of the Upper Wind in England. 
(R rotation, N number of cases.) 
Heights | 05km. | 1:0 km. 15km. 2:0 km. 2°5 km. | 3°0 km. / 
Winter (October-March). | 
Ww & ; 15° 09 TN eal | HS 18° Ite 
ieey| N... 76 76 41 14 5 4 
N R. s 6°5 13°°5 12° 102 —5° 02 
: {N. : 37 37 22 10 4 2 
E R. . 18° 25° tig 195 22° 27° 
; LN. : 37 37 18 10 7 5 
R NR. 16° 26° Ree 36° 37° 45° 
: {N, . 61 eae ee p+ a eae 13) 11 
1 Quarterly Journal R. Met. S., 1908. a 
2 Weekly Weather Report. See also Képpen’s Three Years’ Simultaneous Kite 
Ascents at Berlin, Hamburg, Pavlovsk. This publication was not available until after 
the present Report was printed. 
