Ho" Mr 1'oulett Sorope's observations on the Volcanic 



group of Andernach, Mayen, and the Upper Eiffel. 2. That 

 of the Lower Eiffel. As I visited them during two different 

 excursions, the first from Andernach, and the second from 

 Spa, I may as well retain this division in their description. 



1. District of Andernach, Mayen, and the Upper Eiffel. 



Upon reaching the summit of the steep and richly cultivat- 

 ed slope which, near Andernach, forms the left bank of the 

 Rhine, you suddenly find yourself in a rude and barren coun- 

 try, presenting a strong contrast to the soft and luxuriant 

 scenery you have left behind, and consisting of an elevated 

 mountain plateau of grey wacke slate, across which the deep 

 valley of the Rhine appears but as a narrow trough-shaped 

 channel which the eye overlooks entirely, the plateau being 

 continued at the same level immediately on the eastern side 

 of that river. On the westward the general level rises gradu- 

 ally to the rugged heights of the Upper Eiffel, and it is also 

 partially broken by the narrow and sinuous gorges through 

 which a few tributary streamlets find their way into the Rhine, 

 and still more so by a number of isolated hills of volcanic 

 formation, mostly of a sub-conical form, with which the sur- 

 face of the plateau is irregularly studded. Some >of these 

 hills are very complete volcanic cones, with or without a cen- 

 tral funnel or crater, as the Hirschenberg, near Burg-bruhl, 

 the Bousenberg between that village and Olburg, the Poter, 

 Pellenberg, and lastly, the Camillen-berg, perhaps the high- 

 est and largest of these hills, which appears to rise above 

 1000 feel above the level of the surrounding slate plateau. 

 Others are less regular, seeming to owe their want of sym- 

 metry to their being thrown up on an uneven surface, as the 

 steep side of a valley, &c. Others form elongated ridges, 

 composed of the mingled products of three or four neighbour- 

 ing volcanic orifices. Such are the hills above Nieder-nich. 



Many have regularly funnel-shaped craters; others are 

 breached on one side by the subsequent emission of a lava 

 stream, and some are still more irregular, and appear to have 

 suffered more or less destruction from the mechanical action 

 of some denudating force since their production. All these 

 cones of every kind are composed wholly of loose conglome- 



