Neigklourhood cf the Giant's Causeway^ ^c, 367 



rupted in its course by this wall, and resumed on the other 

 side ot it, precisely at the same level. 



The second dyke is three or four hundred yards further 

 on, towards the north-east; it is a much finer one, and so 

 happily marked that it cannot be mistaken. 



A solitary rock, about 200 yards distant from the main, 

 and visible from a greai |)art of the ^oa.st on each side, h 

 called the Milestone, from its supposed distance from tlie 

 Giant's Causeway, but in reality it is much nearer to it. 

 The precipice here has considerably increased in height, 

 being near to 100 feet, accurately perpendicular, and stra- 

 tified as at the other dyke. 



This second dyke reaches from the summit to the water, 

 beneath which we can see it continued northwards, until 

 it reaches the Milestone, which is a part of ii. 



Though this dyke be also inaccessible, it is plainly form- 

 ed of prisms laid horizontally, and extending quite across; 

 its thickness seems to be about twelve feet. 



The strata are interrupted here, and resumed again, with* 

 out disturbance, at the other side, as before; nor in either 

 case does the slightest separation appear where these dykes 

 meet the contiguous strata, all forming one solid niass. 



The third dyke is situated near the wesleru point of the 

 bay, by which we begin to descend to the Giant's Cause- 

 way ; of this an isolated fragment alone remains, about 

 100 feet long by 30 feet high ; like the rest it is composed 

 of rude prisms laid horizontally. 



Our fourth dyke is at the Giant's Causeway itself ; it 

 divides vertically part of the clilf, at the foot of which the 

 cau«:eway is situated and descends quite down to it. 



The precipice is not perpendicular here, as at the other 

 dykes, by which means our view of this one is partially in- 

 terrupted ; there is, however, enongh of it laid bare to as- 

 certain its nature beyond a doubt, and especially as vt is 

 composed of horizcmtal prisms^ a j>roperty that seems es- 

 sential to all whynn dykes. 



Where this dyke divides the upper part of the columnar 

 stratum which forms the Giant's Causeway, the basalt 

 pillars on the west side of it have fallen from their original 

 vertical position, until they lean forward almost hori- 

 zontally ; while on the east side of the wall they stand 

 steadily vertical. .; 



The basalt septs, which frequently divide the strata in 

 n)ines, and apjiear to be of the same nature with our whynn 

 dvkes, are oenerallv attended bv a sinking or subsidinii; of 

 the strata on one side of them, without disturi)iug the 



paralleliini- 



