Glacial epochs are great
things, but they are vague - vague. Please observe: -
In the space of one hundred and seventy-six years the Lower Mississippi
has shortened itself two hundred and forty-two miles. That is an average
of a trifle over one mile and a third per year. Therefore, any calm
person, who is not blind or idiotic, can see that in the Old Oolitic
Silurian Period,' just a million years ago next November, the Lower
Mississippi River was upwards of one million three hundred thousand
miles long, and stuck out over the Gulf of Mexico like a fishing-rod.
And by the same token any person can see that seven hundred and forty-
two years from now the Lower Mississippi will be only a mile and three-
quarters long, and Cairo and New Orleans will have joined their streets
together, and be plodding comfortably along under a single mayor and a
mutual board of aldermen. There is something fascinating about science.
One gets such wholesale returns of conjecture out of such a trifling
investment of fact.
When the water begins to flow through one of those ditches I have been
speaking of, it is time for the people thereabouts to move. The water
cleaves the banks away like a knife. By the time the ditch has become
twelve or fifteen feet wide, the calamity is as good as accomplished,
for no power on earth can stop it now.
