( 207 ) 
certain influence for, the minima appear about sunrise and sunsot 
and the maxima, as frequently happens, about midday. 
The mean diurnal variation calculated from four maximum and 
from four minimum months does not show any sensible difference, 
DIURNAL VARIATION FOR MAXIMUM AND 
MINIMUM PERIODS, 
H. Febr.-March Sept.—Oct. May-June July-Dee. | Pee EEN 
multiplied by 2. 
Er EE EE NO NE eT 
0— 1 AM 44 17 34: 
1— 2 37 18 36 
2— 3 35 10 20 
3— 4 12 15 26 
4— 5 8 5) 10 
5— 6 6 2 Í 
6— 7 3 min. 4 min. S 
7— 8 3 2 4 
s— 9 11 4 § 
9—10 10 7 14. 
10—11 18 1] 22 
11—12 14 10 20 
0— 1 PM 24. ul 2d. 
max. 
ll 2 21 1] 22 
max, 
2— 3 12 12 24. 
S= 4 21 6 12 
4— 5 17 9 JS 
5— 6 20 12 24. 
6— 7 12 min. 8 16 
7— 8 22 6 12 
8— 9 dd 18 56 
9—LO 31 9 18 
10—11 42 21 max. 42 
1]1-—12 46 21 42 
503 248 496 
15 
Proceedings Royal Acad, Amsterdam. Vol. LL 
