THE TWO GREAT SCULPTORS. \ ig 
more and more as it flows, till at last it will leave this 
too on the plains across which it moves sluggishly 
along, or will deposit it at its mouth when it joins 
the sea. 
You all know the history of the Nile; how, when 
the rains fall very heavily in March and April in the 
mountains of Abyssinia, the river comes rushing down, 
and brings with it a load of mud which it spreads out 
over the Nile valley in Egypt. This annual layer of 
mud is so thin that it takes a thousand years for it 
to become 2 or 3 feet thick; but besides that which 
falls in the valley a great deal is taken to the mouth 
of the river and there forms new land, making what is 
called the " Delta " of the Nile. Alexandria, Rosetta, 
and Damietta, are towns which are all built on land 
made of Nile mud which was carried down ages and 
ages ago, and which has now become firm and hard 
like the rest of the country. You will easily remember 
other deltas mentioned in books, and all these are 
made of the mud carried down from the land to the 
sea. The delta of the Ganges and Brahmapootra in 
India, is actually as large as the whole of England and 
Wales,* and the River Mississippi in America drains 
such a large tract of country .that its delta grows, Sir 
A. Geikie tells us, at the rate of 86 yards in a year. 
All this new land laid down in Egypt,' in India, in 
America, and in other places, is the -work of water. 
Even on the Thames you may see mud-banks, as at 
Gravesend, which are made of earth brought from 
the interior of England. But at the mouth of the 
Thames 'the sea washes Up very strongly every tide, 
* 58,311 square miles'. 
