's a bigger piece of work than the Panama Canal, and a more
difficult piece of work. It means millions of dollars every year to the
people of the United States."

"Why is it such a hard job?"

"The Mississippi River," the Forecaster began, "is two and a half
thousand miles in length; the longest river in the world."

"Longer than the Amazon?" asked Anton.

"Yes, a great deal. Besides, it is navigable for nearly two thousand
miles, clear from St. Paul, Minnesota, to the Gulf. It drains two-fifths
of the area of the United States. To put it another way, all the rain
and snow that falls between New York State and Montana sooner or later
makes its way into the Mississippi River, except for the rain that is
used up by plants and animals or that is evaporated before it reaches
the river or that drains by underground seepage to the ocean. So you see
what a vast amount of water it must carry. Now, boys," he continued,
"what kind of banks has the river around here, rock or earth?"

"Mud!" answered Ross, tersely.

"Right," the Forecaster agreed, "and it is mud nearly all the way along.
But do you know what mud is?"

This was rather a poser, but finally Anton said slowly,

"It's a mixture of earth and water, isn't it?"

The Forecaster looked shrewdly at the boy.

"You've hit it just right," he said, "mud is earth or soil that has been
washed down by the river. That's what makes the bottom of the river so
irregular and why it's always shifting. You can see for yourselves,
boys, that if the bottom of the Mississippi is just made of light mud,
light enough to be carried down as muddy water for hundreds of miles,
any little change in the current of the river will stir up that mud
again and scoop out a hole. If it happens to be near a bank, the bank
will be eaten away and, naturally, will cave right in."

"About how much mud does the Mississippi carry down, Mr. Levin?" Anton
asked.

"In flood time, as much as a thousand tons a minute will be carried past
here."

Ross whistled.

"A thousand tons a minute!" he exclaimed. "Why, I should think that
would fill up the river in no time."

"It would," the Weather Man answered, "if the river stood still. In
flood time, however, the water is flowing rapidly and takes the mud
clear down to the delta. That's why there is always so much new land
being made at the mouth of the river. You could buy a piece of land
under water now, Ross, if you wanted, and be quite sure that in twen