281 



proportionably increased ; consequently contributing 

 to the increase of the alluvial depositions at the 

 mouths of those rivers. 



The next circumstance of importance that we have 

 to examine in this case, is the nature, extent, and ope- 

 ration of the tides, on the currents of those rivers. 



The river Indus, discharges its waters into the gulf 

 of Scindi, on the eastern border, and nearly at the ex- 

 tremity, or bottom of the Arabian Gulf. 



"The tide in the Indus/' says Mr. Rennell, " is 

 perceptible at about sixty-five miles above its mouthy 

 according to the information of Mr. Cullender, who 

 resided a considerable time at Tatta, near the head of 

 the delta of the Indus."* 



This, we have reason to believe, is true ; for it is 

 said that the Red Rea. in about the same parallel of 

 latitude, does not rise one foot perpendicular in the 

 middle of the sea. 



" The rise of the tide, at new and full moon, is 

 about three feet and a half at Suez," (here the waters 

 are driven into a contracted part of the sea, at its ex- 

 tremity, and compressed ; consequently raised higher 

 than in the open sea, where it is broader.) *< but less 

 than one foot in the mid le part of the Red Sea. At 

 the entrance it is four feet."f 



Here too the tide waters of the sea are again com- 

 pressed, at the straits of BabelniMndel, or between the 

 coast of Africa and Arabia. So that if we admit the 



* Rennell's Map, p. xxiv. f Kennell's Herodotus, p. 476. 

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