^2S Institule of Prante. 



of the great operation of levelling the two seas by the isthmtfs of 

 Stiez, M. Le Pere, or rather the reporter of his memoir, ob- 

 §grves : " This levelling resolves the celebrated question agitated 

 shice the days of the ancients respecting the elevation of the 

 Red sea above the Mediterranean sea and the soil of Lower 

 Egypt: we thereby discover that the low-water mark of the 

 Mediterranean is lower by eight metres and 121 millimetres than 

 the low- water mark; and nine metres and 907 millimetres lower 

 thain the high-water mark of the Red sea. We also find that 

 the total slope of the hill from Cairo to Rosetta, in a distance 

 of 252,000 metres, varies by about eight metres from the lowest 

 to the highest level of the waters : the mean declivity when the 

 river is at its lowest ebb is -5-5-5'' Ai^=: 0,0002, and at its fullest state 

 in September 1798 this declivity became VtVoVo" = 0,00051. 



" The difference between the high and the low-water mark 

 at Suez is one metre 7S6 millimetres: the Nile in its most 

 swoln state at Cairo is superior at first by eight metres 960 

 millimetres, and in the second stage by four metres 740 milli- 

 metres: at its lowest state at the same place it is inferior to the 

 low-water mark at Suez bv two metres S36 millimetres. 



" The point in the vast basin of the bitter lakes is remarkable 

 for its being nearly eight metres below the low-water mark of 

 the Red sea : other points of land, and even places which are in- 

 habited, are below the level of both seas; and an immense extent 

 of ground, very little elevated above the Mediterranean, is far 

 below the Red sea ; so that the waters of the latter might cover 

 the surface of the Delta, and the well founded fears of this sub- 

 mersion may have caused great alarm at distant epochs, when 

 the Delta was still lower than it is at present." 



M. Le Pere and the Comicil of the Institute, to whom his 

 memoir was referred, conclude by asserting, that it is quite 

 practicable to re-open the communication I)y means of canals 

 ijctwecn the Red sea and the Mediterranean. 



Aiitract of the Labours of (he Clas< of Mnthcmalicnl and Ph}/" 

 sical Sciences during ike Year IS 14. B]/ M. Cuvier, per- 

 ptlual Secretary. 



" The memorable events of w'hich the French capital has been 

 the theatre, far from interrupting our scientific researches, have 

 furnished new proofs of the respect which the sciences hispire, 

 and of the great influence which they have acquired over men of 

 all ranks and professions. Innumerable armies from the ex- 

 tremities of Europe have visited our monuments, have examined 

 our collections, without their sustaining the slightest damage. 

 Friends of science, enrolled m. tbia grand crusade, uiKlettaken 



