Principal Depressions on the Surface of the Globe. 259 



stration which makes no attempt to heal the wounds after they have been 

 inflicted. 



The Bitter Lakes occupy a series of hollows about 30 miles in length, 

 10 in breadth, and 50 feet in depth, under high water mark in the narrow 

 neck of land intervening betwixt the Red and Mediterranean Seas. They 

 seem at one time to have formed the upper portion of the Gulf of Suez, 

 which was cut off from them by the rising of the desert barrier of about 

 13 miles, which now divides them. The water now found in them is ex- 

 tremely salt and bitter — the result of concentration. The isthmus, which 

 is only 70 miles from sea to sea, seems within the last 4000 years to have 

 been subjected to frequent elevations and depressions, the latest of which 

 in all likelihood occurred a considerable time after the Exodus. 



The Natron Lakes, in the upper part of the Delta, are also completely 

 isolated, and occupy a depression of considerable but uncertain depth. In 

 summer they are nearly saturated with salt, the muriate and subcarbonate 

 of soda, or the sea-salt and soda of commerce. In winter they rise, and 

 become freshed, from the percolation of the waters of the Nile, which ap- 

 pear to take about three months to force a passage through the porous 

 soil beneath. 



Before noticing Palestine, close by the locality just described, we 

 shall close the account of the known depressions in Africa with a notice of 

 the lake of Assal, on the Somali shore opposite Aden. The lake was, I 

 believe, first surveyed by the party of Sir W. Harris, in 1841 ; it is de- 

 scribed by him, as well as by Dr Kirk and Captain Barker, who took its 

 level and dimensions. It is in lat. 11° 33' 12" N., long. 42° 3<y 6" E. 

 It is about 7 miles in length, 16 in circumference ; and its surface is 570 

 feet beneath the level of the sea. No stream or rivulet enters it, or flows 

 from it ; scarcely any rain ever falls in its neighbourhood ; its waters 

 dried up and concentrated by evaporation, have nearly reached the point 

 of saturation, and about one-third of the lake is at certain seasons covered 

 with a sheet of solid salt. It is separated from the outer sea, of which it 

 at one time formed a part, by a barrier of lava, cracked and rent in all 

 directions, the whole being obviously the result of recent volcanic agency, 

 accomplished, probably, when the vast group of cones extending from 

 Aden 500 miles into Abyssinia, and at least 300 up the Red Sea, were in 

 a state of conflagration. Under operations so violent and extensive as 

 may then be supposed to have been in progress, the upheaval of a barrier 

 a few dozens of miles across, and severation from the sea of a lake about 

 the size of the island of Bombay, would appear a very trifling affair. 



Turning from Assal I shall take up the depressions in India, few and 

 inconsiderable as they are, before dealing with those of Western and 

 Central Asia. The most noticeable are the Liunn of Cutch, the Boke, the 

 Null, and Lake Loonar. The remarkable thing about the first of these 

 is that it has obviously been subjected to a variety of descents and up- 

 heavals within the human or probably historic period. Any one who 

 reads the Periplus with care, will, I think, come to the conclusion that a 

 vast space from the Indus eastward which is now dry land was in the time 

 of Alexander covered by the waves. There is a Hindoo tradition that 

 the sea in days of yore swept over the present Runn and extended for 

 many miles beyond it, and a line of positions along the old sea margin 

 indicate by their names the ports, custom-houses, and other chief points 

 along the shore. A saint offended with the wickedness of the people cursed 

 the land, and ordered the sea to retire, an event believed by Colonel Grant 

 to have occurred in the eleventh century. The ruins of the city of Bhali- 

 bapoora near Bhownuggur are now found from 10 to 15 feet below the 

 surface of the soil ; but the houses it is clear must have been constructed 

 on dry land, and sunk beneath the waves for at least the distance just 



