1916-17.] The Formation of Anticy clonic Stratus. 139 
small anticyclone from the North Sea to Southern Russia from 22nd to 
25th September 1916. On the 22nd there was a light surface wind from 
the E., which changed to S.S.W. about 9 a.m. on the 23rd ; on the 24th it 
was still S.S.W., but on the 25th it was from the S.E. The temperatures 
for the period were as follows : — 
Height in Feet (above 
Surface). 
Temperatures 
in Degrees F. 
September 22. 
8.30 a.m. 12 noon. 
September 23. 
6 a.m. 
September 25. 
1.30 p.m. 
Surface (300 feet above 
sea -level) 
o 
o 
o 
44 
o 
72 
500 
52 
• . . 
48 
... 
1000 
... 
... 
52 
67'5 
2000 
46 
... 
50 
63 
3000 
42 
45-5 
46 
61 
3800 
... 
... 
43 
... 
4000 
38 
41-5 
44 
... 
4500 
... 
39 
54 
54 
5000 
45 
44 
55‘5 
... 
6000 
43 
... 
53 
47 
6500 
44 
... 
51*5 
... 
On both 22nd and 23rd September there was haze to the level of 
minimum temperature, but only a few small clouds. It is seen that between 
noon on the 22nd and 6 a.m. on the 23rd, while the warm air descended 
from about 5000 to 4500 feet and increased considerably in temperature, 
the temperature up to 3000 feet had hardly risen ; possibly radiation from 
the hazy air during the night compensated for any increase of temperature 
due to descent. A further descent appears to have taken place between 
the 23rd and 25th ; but the whole set of observations is complicated by the 
fact that the air was in motion throughout the period. The reversed 
temperature gradient was probably originally developed above the stratus 
clouds at 5000 or 6000 feet on the 20th and 21st, with a north wind. 
Again, between 10 a.m. on 25th April and 12 noon on the 26th, 1916, the 
level of the top of the haze descended from about the 5000-feet level to the 
3000-feet level, and the temperatures were as follows : — 
Height in Feet 
(above Surface). 
Temperatures 
in Degrees F. 
April 25. 
10 a.m. 
April 26. 
12 noon. 
Surface 
62 
69 
3,000 
... 
53 
5,000 
43 
56 
7,000 
47 
... 
10,000 
39 
... 
11,000 
... 
36 
