THE HAMILTON ASSOCIATION. 33 



thousands of miles. It was from that sandstone the Temples of 

 Upper Egypt were built. Through these rocks the Nile flows at an 

 average rate of three miles an hour. The valley through which it 

 runs varies in width from four to thirty-two miles. Rawlinson 

 estimates the average width of the Nile to be a mile ; of the Nile 

 Valley to be seven miles ; and the cultivated breadth of the Valley, 

 in consequence of its being flanked with sand from the desert, he 

 thinks does not exceed an average of five miles. In places, the 

 banks are i,ooo feet high, and resemble huge canal embankments. 



From the Cataracts to the point just north of Cairo, where its 

 bifurcation begins, the Nile from its earliest history has undergone 

 but little change. Below that point there has been great change. 

 Seven channels are mentioned by ancient writers; and although there 

 are still numerous small streams, there are but two navigable chan- 

 nels, which empty into the sea at Rosetta and Damietta. The old 

 courses have long been dry. From Cairo to the Mediterranean the 

 low flat land through which these channels flow, from its similarity in 

 outline to the fourth letter of the Greek alphabet, is called the Delta 

 of the Nile. Its base is not a straight line, as the shore bulges out 

 into the sea. The extreme points, east and west of the Delta, are 

 about three hundred miles apart, and from the southern apex of the 

 Delta to the sea is about one hundred miles. The point where the 

 river forks is said to have formerly been six miles higher up the 

 stream. The course of the mouths of the great river is continually 

 changing. A fourth part of the Delta is covered with shallow lakes, 

 and the water encroaches towards the west. 



The almost unexampled fruitfulness of the Nile Valley is due 

 to the Egyptian climate and to the fertilizing mud left on the fields 

 after the yearly inundations of the river. The tropical rains of 

 Central Africa fall from the middle of May till the middle of 

 September. The Nile, swollen by these rains, continues to rise 

 from June till September, when it remains stationary about a fort- 

 night. In early October, fed by melted snow from the mountains, 

 it rises again for a few days and reaches its highest level, after which 

 it subsides, at first steadily, and then more rapidly, till in January, 

 February and March the fields dry up, and at the beginning of June 

 the river is at its lowest level. At Cairo the average rise of the Nile 

 is 23 or 24 feet, some years it rises 26 feet, and occasionally but 

 22 feet. In Upper Egypt where the river is narrower the water rises 



