298 THE FUTURE OF ARID LANDS 
2 
ce € 
> E 1 a4 2 
> = 100 I rae ras 
2 5 ri es tect ages” : 
G £ 
z D 50 JAPAN 
3 32 STATIONS 
E Cc 1876-1950 (c) 
3 g 
z = 
10 20 3! 
January 
ee 
@ 150 \ 2 A 
5 a e, ee co, | ifs) 
& 2 2 gloe ou uunone 3 
7) is ro NS of ng oe e\ aN 
y 100 We Pe 3 \ af 
Ss e e 5 ri) = G WW q / » 
£ d 6 50 as vd 
USA 
ince 48 STATIONS g PSS UCTORS . 
= - bd 
3 1I8G9- 1950 (b) & 1901-1950 (d) 
c | 
10 20 3I ie) 20 3i 
January Janvary 
Figure 8. The total rainfall for four regions in the northern hemi- 
sphere. 
and the earth passes through these streams year after year as it 
revolves in its own orbit. 
There is only one prominent meteor shower during the month 
of January, namely the Quadrantids on January 3. Going back 
into December, however, there are the Ursids on December 22 
and the Geminids on December 13. It will be seen at once that 
these occur almost exactly 30 days before the world peaks in 
rainfall which have already been discussed. The hypothesis has 
been advanced, therefore, that the phenomenon is due to the 
effects of meteoric dust falling into cloud systems in the lower 
atmosphere, the time difference of 30 days being accounted for 
by the rate of fall of the dust through the atmosphere. 
If this hypothesis is substantiated it might have the most pro- 
found effect on our concepts of artificial control of the weather. 
