314 PEOCEBDtNGS OF THE GEOLOGICAL SOCIETY. [Apr. 5, 



mountain nearly level at the top, which derives its name from a 

 singular hollow, nearly two miles in circumference and 1000 feet 

 deep, lying near to the summit." To this I add my own note*. 

 " It is excavated in a mass of banded limestone and shale, the strata 

 lying horizontally in the face of the cliff, except at the more southern 

 extremity, where they curve upwards. All down the cliff are dis- 

 tinct traces of the erosive action of many streamlets. The floor of 

 the valley below is a level basin, as though it had once held a lake." 

 This was written at the railway station, whence there is a fine view 

 of the cirque. 



Am Ende der Welt, Engelherg. — This cirque is at the termination 

 of the Horbis Thai, a glen descending into the Aa valley just above 

 Engelberg. Less grand than either the Fer-a-Cheval or the Creux 

 de Champs, it is still a striking object, and exhibits the same pecu- 

 liarities of a comparatively level floor, of enclosing precipices, and of 

 numerous waterfalls. The strata in the precipices, which are perhaps 

 about 1500 feet high, are moderately horizontal on either side, but 

 much contorted in the middle. The walls of the cirque, when it is 

 viewed from the loAver end, appear to be crowned with sloping alps, 

 and these to be surmounted with a line of limestone crags. Speaking 

 more correctly, it forms a sudden step or break in the level of an 

 upland valley which lies between two great spurs of the Rothstock 

 massif, and carries the drainage of the Graussen glacier to the Aa. 



It would be easy to multiply examples of cirque-like glens, similar 

 though inferior to these ; but as they would exhibit no fresh features 

 of importance I pass on to my last case, which satisfied me that only 

 one explanation could be offered of their formation. 



The Cirques of the Rothstock. — As the traveller bound from En- 

 gelberg for the Surenen Pass gains the rugged pastures of the 

 Blacken Alp (5833 feet), he sees gradually opening but on his left 

 hand, not one, but two fine cirques cut out of the highest part of the 

 Eothstock massif. They are separated by a spur from the peak 

 named Eothschutz on the Federal Map, and are very similar in ap- 

 pearance, though the eastern one is on the whole the finer of the 

 two. Its other extremity is the Blackenstock (9587 feet), and from 

 this summit to the Eothschutz (9278 feet) runs a line of crags not 

 much inferior in height. The chord joining these two points is 

 about 2800 yards long, and the sagitta of the arc about 650 yards ; 

 but the spurs projecting from the two extremities give a more semi- 

 circular appearance to the cirque than these measurements would 

 suggest. 



Above the usual taluses of debris rises a high band of cliffs of a 

 hard yellowish-grey limestone, which supports a still loftier belt of a 

 reddish rock, doubtless a rather sandy and coarse calcareous shale ; 

 over this is a sort of terrace-shelf or slope, hollowed out into small 

 combes ; and then rises another barrier of limestone cliffs, forming the 

 lip of the cup-like hollow. Clouds prevented me from seeing the 

 sky-line in more than one place ; but it is nowhere more than a few 

 hundred feet below the peaks named above. For the same reason, I 

 * Central Alps, p. 5. 



