This is because the very dry air of that zountry makes Egyptian cotton different from that of our southern states. The fibers (see Fig. 160) are longer, and can be twisted into stronger thread. We are now ;rowing in this country some Egyptian cotton in a place that is sometimes called the "American Egypt". This is in the [mperial Valley, California.
The only other country besides Egypt that has much cotton to sell is India, in &sia. On the plateau near Bombay there is black soil, very rich, which holds water so Nell that cotton thrives with only a little •ain. The people of China also raise much cotton, but they use it all for their own clothes. There are so many people in China that they buy some cotton from the United States and India. (Fig. 166.) 160. Cottonseed oil and oil a long time, the American cotton farmers threw away the cotton seed that they did not need for planting. Then they began to use it for fertilizer. At last someone found that oil could be pressed out of the seeds, and that the oil was good to eat. Cottonseed oil mills are now to be found in many towns and cities from Texas to North Carolina, and cottonseed oil is sold at grocery stores. It may be found in salad oil, or in oleo margarin, or even in boxes of sardines.
The cake, or that part of the cottonseed that is left after pressing out the oil, is ground into a kind of meal, which is• one of the richest of foods for cows and sheep. It is sent to the dairy farms of the northern states and to Europe.
161. Cotton on the Mississippi The cotton map shows that a great deal of cotton is grown.near the Mississippi River because the soil is good for cotton. It is delta soil, brought there by the river. Nearly every boy and girl has seen a delta without knowing its name. Have you not seen little rivulets that form during a hard rain and cut gullies two Or three inches deep in the edge of a road, field, or lot? Farther down, water may run into a little pool, and the earth it carries is spread out like a fan. (Fig. 164.) This fan of earth is called a delta, because it is shaped like the letter delta (A) in the Greek alphabet. You may even see little deltas at the side of a paved city street, where the rain water has piled up on the pavement or in the gutter the dirt it has gathered.
On the steep hills, or in the fields, the rain water cuts channels and carries much soil down to the larger streams. Farther down, where the water of the big river flows more slowly, it drops the sand and mud and builds a delta. Many rivers have
deltas which they have thus built. At first the delta may be only a small island or two -in the mouth of the river. But each year it grows, for the floods make the rivers carry much sand and mud.
The water of the Missis sippi River is always muddy, and every year it carries down to the Gulf of Mexico more mud than could be put into all the freight cars you ever saw. Steamboats on this river often get stuck on sand bars that are built up in the channel over night. But the current soon carries the sand bars away; down at the mouth of the river they may . form again in the gulf. The sandbars that are under the water when the river is high are is lands when the water is low. Every heavy rain helps the river to bring down a little more sand and mud, so that the delta is always growing.
Tiny bits of earth that have been carried from the far-off bare peaks of the Rocky Mountains and the Appalachians have helped to make this delta. You see now how a delta may become so large that it may have many farms, towns, and even large cities upon it.
The delta of the Mississippi (Fig. 165) now reaches far out into the Gulf of Mex ico, and the river adds a mile to it every sixteen years. Ages ago the gulf reached up to the mouth of the Ohio River, but the rivers have filled it in hundreds of feet deep, and have made a soil so very rich that men can grow cotton on it year after year. Delta soil is nearly always good for cotton. Most of the Egyptian cotton is grown on But when the water goes down again, the ground is covered with a layer of rich mud which fertilizes the ground so that good crops will grow. For this reason the flood plains yield twice as much cotton to the acre as the uplands near by produce.
the Nile delta, just as American cotton is grown on the Mississippi delta.
162. Levees.—For many years, the peo ple along the lower course of the Mississippi River have been trying to protect their farms and towns from floods by building high banks, called levees, along the river. Some times the levees break, and the water covers the country for miles and causes great loss on the farms and in the towns. When levees break, men sometimes have to come in boats and take people out the second story win dows, or off the roofs of their homes, and carry them to places of safety.