But what is it which governs these clouds, and makes them do their appointed work? The Psalmist tells us, "At Thy rebuke they flee; at the voice of Thy thunder they are afraid." He gives the same account of it which wise men now-a-days give. It is God, he says, and the Providence of God, which raises the clouds, and makes them water the earth. And the means which He employs is thunder. Now this is strictly true. We all know that thunder gathers the clouds together, and brings rain: but we do not all know that the power which makes the thunder, which we call electricity, is working all around us everywhere. It is only when it bursts out, in flame and noise, which we call lightning and thunder, that we perceive it--but it is still there, this wonderful thing called electricity, for ever at work--giving the clouds their shape, making them fly with vast weights of water through the sky, and then making them pour down that water in rain. But there is another deep meaning in those words of the Psalmist's about thunder. He tells us that at the voice of God's thunder the waters are afraid--that He has set them their bounds which they shall not pass, nor turn again to cover the earth. And it is true. Also that it is this same thunder power which makes dry land--for there is thunder beneath us, and lightning too, in the bowels of the earth. Those who live near burning mountains know this well. They see not only flames, but _real_ lightning, _real_ thunder playing about the burning mouths of the fiery mountains--they hear the roaring, the thundering of the fire-kingdom miles beneath their feet, under the solid crust of the earth. And they see, too, whole hills, ay, whole counties, sometimes, heaved up many feet in a single night, by this thunder under ground--and islands thrown up in the midst of the sea--so that where there was once deep water is now dry land. Now, in this very way, strange as it may seem, almost all dry land is made. This whole country of England once lay at the bottom of the sea. You may now see shells and sea fishes bedded in high rocks and hill tops. But it was all heaved up by the thunder which works under ground. There are places in England where I have seen the marks of the fire on the rocks; and the solid stone crushed, and twisted, and melted by the vast force of the fire which thrust up the land from beneath--and thus the land was heaved up from under the waters, and the sea fled away and left its old bed dry--firm land and high cliffs--and as the Psalmist says, "At the voice of God's thunder the waters were afraid. Thou hast set them their bounds which they shall not pass, neither turn again to cover the earth."