134 Proceedings of the Royal Society of Edinburgh. [Sess. 
The differences of the minimum temperatures of the sheltered and open 
soil are given in Tables VI, VII, and VIII as follows : — 
Table VI. Differences on nights of rapid radiation. 
„ VII. „ „ of strong wind. 
„ VIII. „ during periods of cold rain, sleet, or snow. 
These results make it clear that in practically all weathers such a shelter 
has a marked effect on the temperature of the soil. 
Table VI. — Kadiation. 
Date. 
Air just 
over soil 
minimum. 
Open soil 
minimum. 
Sheltered 
soil 
minimum. 
Difference 
in favour 
of shelter. 
f 
( 
Weather. 
1918. 
December 27 
25-5 
27-0 
32-5 
5*5 
Calm, clear 
55 
31 
29-0 
300 
35*0 
5-0 
55 
1919. 
January 11 . 
29-0 
30-0 
34-5 
4*5 
55 
55 
12 . 
30-5 
30-5 
35-0 
4 5 
55 
55 
15 . 
28*5 
30*0 
35-0 
5-0 
55 
55 
18 . 
26-0 
28-0 
32 5 
4*5 
55 
55 
19 . 
23-0 
24-5 
31-0 
6*5 
55 
February 5 . 
27*0 
28*0 
32*0 
4-0 
55 
55 
8 . 
2D0 
24-0 
29-5 
5*5 
55 
55 
9 . 
19*0 
23*0 
29*5 
6-5 
55 
55 
10 . 
22-0 
24-0 
31-0 
7-0 
55 
55 
12 . 
230 
27*0 
32-0 
5-0 
55 
55 
14 . 
24-0 
29-0 
340 
5-0 
55 
55 
24 . 
27-5 
28-0 
32*5 
4-5 
55 
55 
28 . 
28-0 
28*5 
32 5 
4-0 
55 
March 
2 . 
30-0 
30*0 
35-0 
5-0 
55 
5) 
3 . 
21-0 
26-0 
31*0 
5*0 
55 
JJ 
4 . 
24-0 
27-0 
31-0 
4'0 
15 
Average difference in favour of shelter, 5T° F. 
Some of the advantages of the shelter are as follows : — 
(1) During the period February 1, 1919-March 10, 1919, the mean 
nightly temperature of the sheltered soil was 3*9° F. higher than the 
open soil. 
(2) During this same period the open soil froze on twenty-three 
occasions — falling as low as 23° F. on February 9, and 24° F. on February 
8 and 10. The sheltered soil froze on four occasions only, with a minimum 
of 29 '5° F. on February 8 and 9. 
(3) As on most nights the sheltered soil did not freeze, as soon as 
