In that time it has made, by reason of the detritus brought down by the Nile, a distinctly-marked encroachment on the Mediterranean.

But all Lower Egypt has had a similar origin.

The coast-line near the mouth of the Mississippi has been well known for three hundred years, and during that time has scarcely made a perceptible advance on the Gulf of Mexico; but there was a time when the delta of that river was at St.Louis, more than seven hundred miles from its present position.

In Egypt and in America--in fact, in all countries--the rivers have been inch by inch prolonging the land into the sea; the slowness of their work and the vastness of its extent satisfy us that we must concede for the operation enormous periods of time.
To the same conclusion we are brought if we consider the filling of lakes, the deposit of travertines, the denudation of hills, the cutting action of the sea on its shores, the undermining of cliffs, the weathering of rocks by atmospheric water and carbonic acid.
Sedimentary strata must have been originally deposited in planes nearly horizontal.

Vast numbers of them have been forced, either by paroxysms at intervals or by gradual movement, into all manner of angular inclinations.