THALASSOLOGICAL NOTES ON THE NORTH SEA. 32^) 



passage throug]i chalk rocks. What ^vith the strong- Httoral 

 currents, and the detritns caused by the very considerable 

 encroachment of the sea on the east coast of Lincolnshire 

 and Norfolk, the wonder is that any trace of the original 

 valley should have come down to our times. 



If this theory is accepted Ave have been enabled to trace 

 the course of the Pala^orhine for 60 miles farther than Mr. 

 Harmer. But that is not all. 



One hundred fatliomn soimdinff, North Sea, Lat. 58° 45' N., 

 Long. 0° 22' W. — Precisely 300 miles north from the Silver 

 Pit the first deep sounding is marked as 102 fathoms. N'o 

 other spot in the JWrrth Sea in its vicinity, and none in Eastern 

 Pahvobritannia at loicer latitudes, approaches in the reiiwtest 

 degree to such a depth. 



Channel beticeen the Orknei/ and Shetland Islands. — Oft 

 Sumburgh Head, which constitutes the southern extremity 

 of Mainland Island, Shetland, Lat. 59° 55' N., Long. 1° W., 

 there is again a depth of lOo fathoms in tlie channel com- 

 municating bet-Aveen the Atlantic and the North Sea. Shnilar 

 soujidings occur in the Atlantic, proceeding thence in a 

 N.W. direction, until 48 miles to the W. of Shetland, Lat. 

 ()0^ 44' N., Long. 3° 7' W., a depth of 249 fathoms is 

 attained. Five miles farther on 640 fathoms marked on the 

 chart Avas probably taken at some spot on Professor Hull's 

 Great Declivity. 



Corollary. — Mesozoic strata, Avith Avell-marked eleA'ations, 

 stretch uninterruptedly from the British Channel to York- 

 shire. Farther north the Palasozoic hills are folloAved by 

 Archaic rocks, rising into noble mountains in the lake 

 district of the North of England and in Scotland. If we are 

 correct in tracing the Pala3orhine as far as the Silver Pit 

 there is no way AvhatcA^er out of the dilemma, unless Ave 

 admit frankly that it must have folloAved a northerly course, 

 probably passing by the two points referred to, and finding 

 its Avay somehoAvinto the Atlantic after reaching the Avestern 

 shores of Pal^eobritannia, of Avhich (between the Hook of 

 Holland and Shetland alone) it must have fertilized upwards 

 of 600 miles, thus doubling its present length. 



The principal tributaries to the left Avould have been 

 successively : the Palteoschelt, the Palaeothames, Pala^o- 

 humber, Palaeoforth, Palteotay, etc. By such an extension 

 of its Thalweg it must have been comparable in size in days 

 of yore to the Oronoco, or by its geographical position to 

 the Mackenzie river or Yenisei. 



