( Mi ) 



1876 the velocity-cürve for a place near the Red Sea is known 

 both for springtide and for neaptide. Il has been represented in 

 the following figures. \i 



Mean velocity-curves at the entrance of the Suez-canal 



Springtide. 



o 



53 



bo 



O 



X) 

 £3 



ÜJ 



C 



Velocity. 



i.ooM 



Neaptide. 





O 

 53 



-G 



W 



Moon-hours after lowwater. 



3 



The above velocity curves probably do not represent the mean 

 velocities but the velocities in the middle of the canal. They have 

 been derived from measurements made every hour partly by means 

 of floats partly by means of the current meter of Woltmann. 



It deserves attention, however, that at the time of these observations 

 the Suez-canal had still only a depth of 8 M. below low water and 

 a bottomwidth of 22 M. The section of the canal is now being 

 increased to a bottomwidth of 45 M. and a depth of 10,5 M. below- 

 low water. The velocities in the widened canal may perhaps exceed by 

 20 percent those observed on the canal during the period 1871 — '187(1. ■') 



') These curves are borrowed from the Etude du régime de la Marée dans le 

 canal du Suez par M. Bourdelles, in the Annales des Pouts el Ghaussées of 1898. 

 They occur originally in a Note sur le régime des eaux dans le canal maritime 

 de Suez et a ses embouchures in 1884 by Lemasson Chief Engineer of Ihe canal- 

 works. 



2 ) For the original cross section of 8 M. depth below low water, 22 M. bottom- 

 width and slopes of 1 vertical on 2 horizontal we have: 



Area 7=304 M 2 ; wet circumference = 57.9 M., consequently E =5.25 M. 

 For the future cross section of 10.5 M. depth, 45 M bottomwidth and slopes of 

 1 vertical on 2'/ 2 horizontal, we will have: I = 74!) M 2 ., = 101.5 M. therefore 



R = 7.37 M. Now / = 1-20. 



V 5.25 



