26 



309.632 Feet. 



30S.976 Feet. 



308.320 Feet. 



must either build a masonry wall or reduce the slope and riprap it. It 

 is quite common to jDut spurs in the banks some distance above the 

 points threatened to throw the current farther out in the stream. 

 This is often a dangerous expedient, as the current thus deflected niRy 



do considerable damage at other points. 

 Fig. 3 shows one of these spurs con- 

 s'^ructed by the government. 



NILE GAGES. 



Much has been written about the flow 

 of the Nile, yet it has never been care- 

 fully measured until recently. Although 

 Nile gages, now known as '' nilometers," 

 were established at an early date, the 

 relation between the gage heights and 

 the discharge was never determined until 

 during the last half century. The meas- 

 urements first made, even b}- persons 

 qualified for sut-h work, were rough and 

 can be regarded as onh' aiDproximate. 

 The use of the current meter has finally 

 permitted accurate gagings to be made, 

 and it will doubtless not be long until 

 enough of these have been taken to 

 give value to the gage heights alread}" 

 recorded. 



On many of the rocks along the Nile 

 in Nubia extreme high-water levels have 

 been recorded. Such marks were doubt- 

 less the earliest gages of the Nile. Dur- 

 ing the past few years some old gages 

 have been discovered at Assiut and other 

 points along the river. The most inter- 

 esting and among the most ancient of 

 the gages are on the island of Philae. 

 The two which can be seen to-day are on 

 the west side of the island. They con- 

 sist of- a- narrow stairwa}^ leading by a short subterranean passage 

 from the surface of the ground on the island to the river. The 

 gages are placed on the walls of this passageway and are in sections 

 of 3 or -i feet each. The ancient gage is graduated in cubits or 

 pics and kirats. On the Nile gage toward the south end of the island 

 of Philae there are a number of different scales, the most modern 

 one being graduated in meters and centimeters, similar to the gage 

 on Elephantine Island, as shown in the accompanying cut (fig. 4). 



.307.ee4 Feet. 



307.00S Feet 

 above sea level. 



Fig. 4.- 



-Xilometcr on the Elphaiitint' 

 Island. 



