1913-14.] 
Principia Atmospherica. 
103 
3. Sounding of November 6 , 1908, 10h. 55m. a.m. 
Reversal of Direction from E.S.E. in the lowest three kilometres 
to W.N.W. in the reach from 4 kilometres to 9 kilometres. 
Table VII. 
Height. 
Distance of next higher 
isobar in kilometres. 
Distance of next higher 
isotherm in kilometres. 
k. 
k. 
k. 
k. 
k. 
8-9 
185 S 
356 W 
96 S 
312 W 
7-8 
204 S 
356 W 
416 S 
770 W 
6-7 
200 S 
416 W 
294 S 
189 W 
5-6 
233 S 
435 W 
139 S 
625 E 
4-5 
344 S 
665 W 
101 S 
109 W 
3-4 
5000 S 
4000 E 
119 S 
270 W 
2-3 
588 N 
416 E 
286 S 
108 W 
1-2 
100 N 
142 E 
24 S 
65 W 
0-1 
77 N 
172 E 
34 N 
40 E 
The gradual diminution of velocity up to 4 kilometres, where the 
isobars become very wide apart, is well marked in the second and third 
columns ; and it is seen that the reversal is to be accounted for by a rapid 
rise of temperature to the south-west in the second and third kilometres, 
with a similar distribution of temperature of less marked character in 
the higher layers. 
It will be noticed that in the second and third kilometres, where the 
reversal is determined, the slope of temperature is opposite to the slope of 
pressure, a condition which we have already noticed as being characteristic 
of large change of pressure-difference with height. In the sixth kilometre 
the next higher isotherm is found a long way off on the east instead of on 
the west, as in the layers above and below. The change is not really very 
. large, as the temperature conditions are nearly uniform in that region as 
regards the west-to-east direction, but it furnishes a reminder of the close 
association which we must expect to find between slight changes in 
temperature distribution and in the direction and force of the wind. 
4. Sounding of April 29, 1908. 
North-Westerly Current in the Upper Layers crossing a Lower 
Current from the South- West. 
This is the example of which the details of the working are shown in 
the table on p. 100, and it is one of great interest, because it is characteristic 
