rest of the mud.  In this way the whole valley has been carved out into fine pillars, some still having capping-stones, while others have lost them, and these last will soon be washed away.  We have no such valleys of earth-pillars here in England, but you may sometimes see tiny pillars under bridges where the drippings have washed away the earth between the pebbles, and such small examples which you can observe for yourselves are quite as instructive as more important ones.

Another way in which rain changes the surface of the earth is by sinking down through loose soil from the top of a cliff to a depth of many feet till it comes to solid rock, and then lying spread over a wide apace.  Here it makes a kind of watery mud, which is a very unsafe foundation for the hill of earth above it, and so after a time the whole mass slips down and makes a fresh piece of land at the foot of the cliff.  If you have ever been at the Isle of Wight you will have seen an undulating strip of ground, called the Undercliff, at Ventnor and other places, stretching all along the sea below the high cliffs.  This land was once at the top of the cliff, and came down by succession of landslips such as we have been describing.  A very great landslip of this kind happened in the memory of living people, at Lyme Regis, in Dorsetshire, in the year 1839.

You will easily see how in forming earth-pillars and causing landslips rain changes the face of the country, but these are only rare effects of water.  It is when the rain collects in brooks and forms rivers that it is most busy in sculpturing the land.  Look out some day into the road or the garden where the ground slopes a little, and watch what happens during a shower of rain.  First the rain-drops run together in every little hollow of the ground, then the water begins to flow along any ruts or channels it can find, lying here and there in pools, but always making its way gradually down the slope.  Meanwhile from other parts of the ground little rills are coming, and these all meet in some larger ruts where the ground is lowest, making one great stream, which at last empties itself into the gutter or an area, or finds its way down some grating.

Now just this, which we can watch whenever a heavy shower of rain comes down on the road, happens also all over the world.  Up in the mountains, where there is always a great deal of rain, little rills gather and fall over the mountain sides, meeting in some stream below.  Then, as this stream flows on, it is fed by many runnels of water, which come from all parts of the country, trickling along ruts, and flowing in small brooks and rivulets down the gentle slope of the land till they reach the big stream, which at last is important enough to be called a river.  Sometimes this river comes to a large hollow in the land and there the water gathers and forms a lake; but still at the lower end of this lake out it comes again, forming a new river, and growing and growing by receiving fresh streams until at last it reaches the sea.