Page:Geology and Mineralogy considered with reference to Natural Theology, 1837, volume 1.djvu/420

 416 affords one of the many proofs of Design, which arise out of the investigation of its actual condition, and of its relations to the organized beings which are placed upon it.

Nearly three-fourths of the Earth being covered with Sea, whilst the remaining dry land is in need of continual supplies of water, for the sustenance of the animal and vegetable kingdoms, the processes by which these supplies are rendered available for such important purposes, form no inconsiderable part of the beautiful and connected mechanisms of the terraqueous Globe.

The great Instrument of communication between the surface of the Sea, and that of3the Land, is the Atmosphere, by means of which a perpetual supply of fresh water is derived from an Ocean of salt water, through the simple process of evaporation.

By this process, water is incessantly ascending in the state of Vapour, and again descending in the form of Dew and Rain.

Of the water thus supplied to the surface of the land, a small portion only returns to the Sea directly in seasons of flood through the channels of Rivers;

A second portion is re-absorbed into the Atmosphere by Evaporation;

A third portion enters into the composition of Animal and Vegetable bodies;

A fourth portion descends into the strata, and is accumulated in their interstices into subterraneous sheets and reservoirs of water, from which it is discharged gradually at the surface in the form of perennial Springs, that form the ordinary supply of Rivers.

As soon as Springs issue from the Earth, their waters commence their return towards the Sea; rills unite into streamlets,