Watches are kept on those narrow necks, at needful times, and if a man happens to be caught cutting a ditch across them, the chances are all against his ever having another opportunity to cut a ditch.
Pray observe some of the effects of this ditching business.

Once there was a neck opposite Port Hudson, Louisiana, which was only half a mile across, in its narrowest place.

You could walk across there in fifteen minutes; but if you made the journey around the cape on a raft, you traveled thirty-five miles to accomplish the same thing.

In 1722 the river darted through that neck, deserted its old bed, and thus shortened itself thirty-five miles.

In the same way it shortened itself twenty-five miles at Black Hawk Point in 1699.