VOLUME AND PERIODICAL RISING OF THE NILE. 69 



begun their great works of canalisation. Doubtless most of the monuments 

 erected near the river, such as the slabs of stone paving the great avenue of 

 sphinxes at Karnak, the colossal statues of Meranon, and even a block bearing a 

 comparatively recent Greek inscription, are now found buried to some depth below 

 the surface. But this is due not so much to change of level as to subsidence, such 

 huge masses naturally sinking gradually in the alluvial soil of the riverain plains. 

 In the same way the erratic boulders in Switzerland and the colonnades of the 

 Roman temples have sunk more and more below the surrounding surface. The 

 Nilometer discovered by Girard in Elephantine Island is perhaps one of those 

 monuments whose foundations have thus given way. Hence although the present 

 high-water mark may exceed the old measurement by 8 or 9 feet, it does not 

 follow that the bed of the river and its banks have been raised to that extent. 

 Such a phenomenon could not be reconciled with the drying up of the old bed east 

 of Asuan, which has now been abandoned by the stream. 



Volume and Periodical Rising of the Nile. 



The yearly overflow of the Nile, which renews all nature, and which was 

 celebrated by the Egyptians as the resurrection of a god, is of such regular 

 occurrence that it was formerly compared with the revolutions of the heavenly 

 orbs. How could the riverain populations refrain from worshipping this stream, 

 " Creator of wheat and giver of barley," a stream but for which " the gods would 

 fall prostrate and all men perish " ? " Hail, Nile ! " sang the priests of old, 

 " Hail, thou that comest to give life to Egypt ! " According to its periodical 

 return all things were and still are regulated — field operations, town work, civil 

 and religious feasts. But at present it is easier to prepare for the rising waters, 

 which are announced from Khartum thirty or forty days beforehand. They begin 

 to appear nearly always on June 10th, at first " green " with vegetable refuse 

 from the great lagoons of the upper basin. But the rise is very slight till about 

 the middle of July, when the stream becomes suddenly swollen by the " red " 

 waters from the Abyssinian highlands. Towards the end of August the Nile is 

 nearly full, but continues to increase slightly till October 7th, when it usually 

 reaches its culminating point. After this date the subsidence sets in and continues 

 very gradually till the return of the floods the following June. 



During the three months of high water the Nile sends seawards a liquid mass 

 equal to about three-fourths of the whole annual discharge, or 3,150 billions cubic 

 feet out of a total of 4,200 billions. High-water mark naturally diminishes down 

 stream, falling from about 56 feet at Asuan to 24 or 25 at Cairo. Relying on 

 some of the old texts, especially a much-disputed passage in Herodotus, some 

 writers suppose that the level of the floods has been considerably modified since 

 the first centuries of Egyptian history, although suflicient data are lacking to 

 determine the point with certainty. In any case the mean elevation has under- 

 gone no change since the end of the eighteenth century of the new era. The 

 careful measurements taken at that time have since been maintained, and they are 



