the fact that at present we do not even know exactly how rain
begins.[58] Learning to predict it and to modify it, through space
application, might help slow down the soil erosion of arable land--that
"geological inevitability * * * which man can only hasten or
postpone."[59] It is noteworthy that the two leading nations in space
research, the United States and the U.S.S.R., are among the most
affected by soil erosion.

The "leg up" which the United States has in this particular phase of
space research is illustrated by the acute photographic talents of the
Tiros satellite and their meaning to weather experts. The following
description of some of the earliest pictures by the Director of the
Office of Meteorological Research, U.S. Weather Bureau, is illuminating.

This picture, labeled "No. 1," was the storm that was picked up in
the early orbits of Tiros on the first day of launch, April 1. This
shows the storm 120 miles east of Cape Cod, with dry continental
air streaming off the United States, not shown by clouds, and off
the coast the moist air streaming up to the north, counterclockwise
around the center, producing widespread clouds and precipitation as
far north as the Gulf of St. Lawrence.

On that same day mention was made of a storm in the Midwest. That
is illustrated by photograph No. 2. This was centered over
southeast Nebraska, a rather extensive storm. Again, we have a
clear air portion shown by a dark area, the ground underneath,
which has less brightness than the clouds, the cold air from Canada
streaming into that area, not characterized by clouds, and to the
east the moist air from the Gulf of Mexico, in this general
neighborhood, streaming around into that center and producing
rather widespread rains. In this case near the Gulf of Mexico,
where the cloud is extremely bright, indicating that the clouds are
very high, thunderstorms were found in that area.

[Illustration: FIGURE 12.--Storm center over Nebraska
photographed by the first U.S. weather satellite, Tiros, on April
1, 1960. The extent of the picture can be seen from the
accompanying weather map.]

It is a sort of situation in which tornadoes are to be found in
this very bright cloudy area, especially this time of year in the
Midwest.

A third vortex was observed, also April 1, in the Gulf of Alaska,
500 mi