Much of the loam which the river has brought down has been spread over the valley, but a considerable amount has been emptied each year at the mouth of the stream, forming in course of time a _delta_,--so called by the Greeks from its resemblance to their letter _delta_. Because of its long threading valley and this delta, Egypt has sometimes been likened to a lily; the delta representing the flower and the valley the stem. After flowing four thousand miles, the waters of the Nile find their way at last to the Mediterranean Sea, and towards this sea the land gradually slopes. Passing southward through Egypt from the Mediterranean, one journeys more than a hundred miles through the delta. This great plain has been formed entirely of the mud washed down by the mighty river. Each year for countless ages it has been extended at least eight feet farther into the sea, and thus its area continues to increase. This portion of the country, or this delta, is frequently referred to as Lower Egypt. Continuing south, one enters the valley. This narrow strip of fertile land measures about six hundred miles from the apex, or southern extremity of the delta, to the first cataract. The bed of the Nile is very irregular in its upper course and falls over ten cataracts in its downward flow before the southern boundary of Upper Egypt is reached. In width the valley varies from one to ten miles. This portion of the country is known as Upper Egypt. Imagine, if you can, a river flowing through a valley skirted on either side by deserts whose boundaries are so abruptly marked that one may stand with one foot in the fertile, life-producing valley, and with the other in the shifting sands of desert waste. On the east lies the Arabian desert, while the many colored peaks of a lofty mountain range form a well nigh impassable barrier between it and the Red Sea, save where famous mountain passes lead to the waters beyond. Nubian mountains, to the south, supplied most of the gold and precious ore used by the ancient Egyptians, and were held in greatest dread by those taken in captivity, for the work within them was relentless and none ever returned when once sent to join the hopeless, heartsick throng of laborers employed by the king to develop the mines. The Sahara west of the valley is not a flat region, but is made up of shifting sands, hills and rocks of limestone. It is plain that the Valley of the Nile was once a part of this desert, but the river, with its tremendous volume, set to work to cut down its bed. The channel, so worn down, is the present valley. "Egypt is the temporarily uncovered bed of the Nile, which it reclaims and recovers during a portion of each year, when Egypt disappears from view, save where human labor has by mounds and embankments formed artificial islands that raise their heads above the waste of waters, for the most part crowned with buildings."[1]