ppi, and there are scores of
them."

"What can be done, Mr. Levin?"

"There's only one thing to do," the Weather Man answered, "and that's to
build up the levee system, year after year, steadily and without pause,
making allowances for the tributaries flowing into the Mississippi and
paying especial heed to the rainfall that may be expected in the basin.
Wherever possible, forestry must be undertaken to keep the slopes from
erosion. Reservoirs might be built with great profit, from which water
could be let down during the low water periods.

"When the river channels are accurately adjusted to the amount of
rainfall in the river basin, destructive floods will be averted. We can
never expect that the Mississippi will be absolutely put in harness. The
basin is too huge, the amount of water that has to be carried down is
too great. Permanent dredging and permanent levee construction and
repair will always be necessary, and a close co-ordination between the
Weather Bureau and the government and state engineers is a first need in
the problem."

"Just how does the Weather Bureau come in," asked Ross, "the rainfall?"

"It isn't only the rainfall of the few days in advance," the Forecaster
answered, "it's the rain that has fallen before and the rain that's
going to fall. If there should be twelve inches of rainfall after a
long drought throughout the Mississippi basin, it would make
comparatively little difference, for all the rain that fell on the dry
ground would be sucked up by it and only a very little would flow into
the rivers and streams that feed the Mississippi.

"On the other hand, if there had been slight but frequent rains for
weeks and weeks, those twelve inches of water would make an entirely
different story. No one, except the Weather Bureau, would have kept
track of the amount of rain that had fallen.

"If the ground has been steadily soaked, even by light occasional
showers, twelve inches more of rain cannot soak in. Therefore, the
entire amount of rain will flow directly into the stream channels and
thus into the Mississippi. Flood warnings will be sent out, the height
of the flood crest can be estimated, the length of the period of the
danger will be known in advance and the proper preparations can be made.
If further rain is threatened, that information can be sent out, also,
and the entire Mississippi valley is completely prepared. That's the
true preparedness, my boy, being ready for the foe that yo