146 Transactions of the Royal Society of South Africa. ^ 
tentative and partial one may be hazarded for some outstanding features. 
For example, there are differences between the noon, midnight and horizon 
curves which appear to arise largely, if not entirely, from the diurnal 
variation of wind direction. This diurnal variation of direction has been 
Table Showing the Variation of Wind Velocity in Miles an Hour 
during the Course of the Lunar Day at Perigee. 
Hour 
Mean 
Noon 
Midnight 
Horizon 
perigee. 
perigee. 
perigee. 
perigee. 
L.M.P. 
1 0-094, 
9915 
10-265 
9-916 
II 
1 nnm 
l\J UUi 
9*766 
10185 
10012 
III 
£7 57 / O 
9-783 
I0-Q89 
10-009 
IV 
Q-Ql 0 
£7 £7 I V 
9-735 
9-918 
10011 
Y 
9-759 
9 844 
9-939 
YI 
9-804 
9*780 
9912 
VII 
9-907 
9-913 
9-868 
9-932 
VIII 
9-972 
10-032 
9 996 
9-965 
i.2L 
10-007 
lU 114 
1 u uoy 
y yi / 
V 
-A. 
lU 110 
lU Voo 
0 00 L 
XI 
9-995 
10143 
10-080 
9-861 
XII 
9-994 
10125 
9-989 
9917 
U.M.P. 
9-995 
10179 
9-974 
9-896 
XIV 
10-016 
10-252 
9-963 
9-909 
XV 
10-039 
10-358 
9-945 
9-912 
XVI 
10-040 
10-431 
9^891 
9-910 
XVII 
10-026 
10-426 
9-927 
9-856 
XVIII 
9-995 
10-346 
9-995 
9-782 
XIX 
9-995 
10-330 
10-045 
9-754 
XX 
9*992 
10-317 
10-049 
9-753 
XXI 
10-025 
10-385 
10-047 
9-784 
XXII 
10-048 
10 386 
10122 
9-781 
XXIII 
10-078 
10-359 
10-236 
9-786 
XXIV 
10-067 
10-268 
10-282 
9-787 
L.M.P. 
10-050 
10-056 
10-300 
9^863 
Mean 
9-994 
10-132 
10036 
9-882 
Range 
•235 
•696 
•502 
•259 
No. 
864 
226 
269 
369 
described in a preliminary way some years ago (J. R. Sutton, " The Winds of 
Kimberley," ' Trans. Phil. Soc. S.A.,' 1900). G-enerally speaking, we may say 
that the normal resultant winds of Kiml^erley have northerly components 
from sunrise to sunset, and southerly ones during the night ; westerly com- 
ponents from about IX to XX, and easterly ones from XX to IX. Thus when 
the moon (being north of Kimberley) near perigee culminates at noon, the 
