1898.] NATURAL SCIENCES OF PHILADELPHIA. 95 



often found occurring in the Tertiary and more recent periods. I 

 confess that nowhere in ray travels, either in this country or in 

 Europe, did I observe such colossi of basaltic columns. When 

 in their entirety they must have been giant structures in the strict- 

 est sense of the phrase. An interesting and very suggestive rock 

 received the name of the Haystack from the owner of the place. 

 Plate III represents the same as viewed from the southern side. 

 As the illustration indicates, the side to the right is convex, and if 

 one stands where he can see the convexity only, a similarity to a 

 haystack or the section of one may suggest itself. 



On close examination I found that the inclined position of the 

 rock was due to tilting, and that formerly it must have stood erect ; 

 it can also be shown that the rocks to the left were parts of the 

 same, and, if the losses through erosion are also taken into account, 

 the Haystack had, in all probability, another outline than the one 

 which it now presents. It seems clear to me that this tall object 

 was originally triangular in form, that it is the last remnant of a 

 crater wall standing there almost separated from the other parts of 

 the crater which lie to the north, northwest and west, while the 

 southern side has entirely collapsed. 



Whoever has closely observed the structure of recent volcanoes, 

 is aware that if it were possible to make a vertical section of the 

 crater wall, that section would necessarily be triangular in form. 

 If it were possible to obtain it, a birds eye view would render the 

 significance of the aspect more convincing. A photograph of the 

 crater wall-section from the west side, Plate IV, represents it fairly 

 well. The camera stood about half way up on the opposite slope, 

 a position which accounts for the depression shown in the central 

 fore ground of the picture. The part from the standing rock to the 

 left, above, is corroded away, plant life here, as everywhere, having 

 doubtless contributed its share toward the destruction of these rocks. 

 The huge blocks seen in front of the tall section, are those which I 

 believe to have been formerly united with the so-called Haystack to 

 form the triangular part of the crater wall. Everybody who has 

 paid the least attention to the study of rocks is acquainted with 

 their continual disintegration, effected by heat and moisture work- 

 ing inward from the exposed surfaces of even the hardest and tough- 

 est rocks. The tall crater wall-section shows even now a great 

 many cracks, especially on its convex side, and it seems evident 

 that it will not require many years to complete its destruction. Its 



