12 THE OCEAN. 



of Gibraltar to the mountains of Africa. A depression of about 1100 

 fathoms would leave nothing but three inland lakes ; to the west a 

 triangular basin occupying the centre of the depression between 

 France and Algeria ; in the middle, a long cavity extending from 

 Crete to Sicily ; and eastward, a hollow lying in front of the Egyp- 

 tian coast. The greatest depth of the Mediterranean, exceeding 

 2200 fathoms, lies to the north of the Syrtes almost in the geome- 

 trical centre of the basin.* 



It is the same with the North Atlantic Ocean as with the Medi- 

 terranean. The depth of the central vallej^ extending from north 

 to south between Europe and the New World, is only known in 

 a general manner. But the gulfs and straits which project from the 

 ocean between the northern countries of Europe, such as the Channel, 

 the North Sea, the Cattegat, the Baltic, have been almost completely 

 explored by the sounding-lead. 



The North Sea in all its northern part, from the 51st to the 57th 

 degree of latitude, presents a mean depth of only about 16 to 27 

 fathoms, except near Newcastle-upon-Tyne, where the bottom is found 

 to be from about 49 to 65 fathoms below the surface. Vast tracts of 

 sand and mud^ — the White bank, the Black bank, the Brown bank, 

 the Dogger bank, the Fisher bank, separated from one another by 

 fosses and lateral channels, deeper by from about 6 to 11 fathoms, 

 almost entirely fill its bed, and stretch as far north as the Shetland 

 Islands. There, as in the centre of a whirlpool, is deposited the 

 murine alluvium, whilst that arm of the ocean follows the precipitous 

 shores of Scandinavia over the rocks and compact clays of the bottom- 

 In these parts the lead descends to about 164 and even 437 fathoms 



Scotland NorAV^ay 





Fig. 4.— Profile of the bed of the North Sea, from the north point of Scotland to Stavanger in Norvray. 



from the surface of the sea ; and in the centre of the Skagerrack, 

 between the sandy beach of Jutland and the bold shores of Norway, 

 nearly 443 fathoms have been reached. One seems to see here, 



* Bottger, das Mittelmeer ; — Mitiheilungen von Petermann, 1866. 



