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10 
DISCUSSION 
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40° heer mee OS 
Fig. 1—Schematie picture of rain distribution and general circulation in lower 
troposphere over Africa in July 
waters of the Nile, Niger, and Congo to reach 
the ocean. However, they should not only be 
kept inside Africa, but inside the southwest 
monsoon, between the two tropical fronts shown 
in Figure 1. We should use any sources of en- 
ergy, in the future atomic energy, for distribut- 
ing it rationally. If the water is spent where we 
already have vegetation and clouds, most of it 
will go through plants, and then that humidity 
will come down again and again. 
Figure 1 shows the structure of the general 
circulation over the whole of Africa in July as 
observed from the ground. This analysis is 
based on ideas I already had in 1928; part of it 
was published in 1929, but only in Russian, so 
nobody here has seen it. The southern tropical 
front moves down to Rhodesia in January. The 
northern one hes along 18-20°N in July, and 
there must be remains of it near the equator at 
the opposite time of the year. So, it seems as if 
the southwest monsoon were enclosed between 
two tropical fronts. The northern one we know 
very well by now; this was confirmed by the work 
of Brooks and Mirrless in 1934. 
The precipitation distribution in Figure 1 is 
shown by shading. Evidently, the equatorial pre- 
cipitation is not at all directly connected with 
the front. It is a pure air-mass precipitation, 
which falls within the region where this very 
humid and unstable air mass is deep enough to 
be able to produce Cumulonimbus. In fact, it 
forms a flow of air that one may really follow. 
So far as I know, there is no other place on Earth 
where you have an air mass that is so well de- 
fined. You have the even flow of moist air com- 
ing in from the ocean. It can not pass through 
the northern tropical front at lower levels, since 
this front surface is a well-established and 
marked one. It leaks out above, at the top of 
the Cumulonimbus clouds, but not so very much, 
because the temperatures are so low there, and 
thus amounts of humidity are very small. So, 
we can use the water of these rivers for impor- 
tant irrigation projects within the outskirts of 
