GiOtOGY bt THE CAMPSIE HILLg. 45 



first, only slightly marked their directions ; but, 

 as they descended, they became deeper and deep- 

 er, until their interstices began to assume an ap- 

 proach towards form, and near to the water, theses 

 forms were seen perfectly columnar. At this 

 place, the columnar forms thus produced, by the 

 congelation and shrinking of the lava, had ge- 

 nerally three, and some of them four sides ; one 

 of which sides, always continued attached to the 

 amorphous mass of lava from which the column 

 had shrunk. Upon some other parts of the shores 

 of this island, I observed these forms arrested in 

 various stages towards complete columnar shape. 

 In some of those situations, the striae or lines had 

 only appeared, in others, form was slightly in- 

 dicated ; in some places they were seen half form- 

 ed, and in others, their formation was complete. 



Upon the sides of the island, where these forms 

 occurred overhanging the sea, I observed that they 

 seldom or ever arrived at a full completion of 

 their figures, until they approached nearly the 

 surface of the water, and they continued perfect 

 in form as far under the surface of the water as I 

 could distinguish them with ray eye. The co- 

 lumnar forms which I saw upon this island, were 

 in general four-sided, but there also occurs among 

 them many of three, and some of five sides ; but 

 those last of pentagonal form, are rare. The ge- 

 neral run of their diameters seldom exceed two 

 feet. 



