on the ffartz. 271 



noticed an example of this fact in the great zone of the 

 Belgic coal measures, and I have stated tliat if the line 

 drawn from Liege to Valenciennes, a line very exactly indi- 

 cating this general direction, is prolonged to the westward, 

 it would in Normandy pass very near the Litry coal mea- 

 sures. Further still, at the extremity of Britanny, the coal 

 measures of Quimper are situated a little below the same 

 line. I have moreover mentioned, at least as an extraor- 

 dinary circumstance, the position of the two coal basins of 

 Sarrebriick and Montrelais (the first we are acquainted with 

 to the south of the preceding line), on another line nearly 

 parallel to the first. I shall now notice another fact of the 

 same nature, which belongs to the object of the present 

 notice, and which appears to me equally worthy of attention. 

 A granitic formation is known to exist in the department 

 of La Manche, on the north of the peninsula of the Coten- 

 tin ; it is known that this formation contains granites, sye- 

 nites, and proiogi/nes, and that the observations of Messrs. 

 Brongniart and Omalius d'Halloy, lead us to regard the 

 whole as of contemporaneous formation with the quartz rocks 

 and schists of the Cotentin and Britanny, some of which 

 contain organic remains. It is also known that this granitic 

 formation constitutes on the E. the most northern capes of 

 the Cotentin ; whilst on the western coast it is found a little 

 further south, so as to indicate a direction from W.S.W, 

 to E.N.E., parallel to that of the schistose rocks of the same 

 country. Now if a straight line is drawn on a map from the 

 granitic mountains of the Hartz to the granitic capes on the 

 E. of Cherbourg, this line when prolonged would traverse 

 the Cotentin in the direction of the granitic baud of that 

 country, and it moreover would very nearly be parallel to 

 the line above mentioned as the general direction of the 

 Belgian coal measures. It should here be remarked that 

 the Cotentin and the Hartz are, in this general direction, 

 the two most northern points in which granite appears on 

 the surface in all that part of Europe which is situated to 

 the south of the Channel and the Bali-.o Sea, and that this 

 rock is no where found in the interval which separates them ; 



