42 



In two contiguous Dykes I obferved, that the axes of thefe prifms were 

 not horizontal as ufual, but in one greatly elevated to the north, and in 

 the other towards the fouth. 



Human attention could not follow the variety which nature has dif. 

 played in the formation of thefe Dykes ; therefore, not to fatigue the 

 reader, I will defcribe but two more particularly ; I feleft thefe, both 

 on account of the new circumflauces attending them, and alfo becaufe 

 they are eafy of accefs, being within a few yards of the great road from 

 Belfaft to Carrickfergus. 



The firft of thefe runs ealtward along the flrand, about four hundred yards 

 fouth of the gallery ; we approached it from the north, and found it com- 

 pofed of long well formed horizontal prifms, lined on the north fide by a 

 fort of bafaltic wall about eighteen inches thick ; this a military gentleman 

 of our party called its revetemeyity I adopt the word on this occafion for 

 convenience. 



After we had traced the Dyke eallward for feveral yards, we obferved 

 this revetement feparate from it, and diverge at a confiderable angle, 

 then, forming a curve, difappear beneath the fand to the north-eart: ; this 

 new circumftance exciting our attention, we traced the revetement back 

 to the Dyke, then along it to the weflward, when after fome time we 

 perceived it entering the Dyke at an acute angle, and croffing it dia- 

 gonally ; when acrofs, it formed for feveral yards a revetement on the 

 fouth fide of the Dyke, then diverging from it, and curving as before, it 

 was again lofl under the fend to the fouth-wefc. 



The fecond Dyke I will defcribe particularly, lies about five hundred yards 

 ■north from the fiJver Jirearn, and about three miles from Carrickfergus ; 

 it feemed compofed of four or five diftinft walls, agglutinated together ; 

 in each of thefe the prifmatic conftrudtion was different from that of the 

 others, and in one the axes of its prifms w?re not as ufual at right angles, 

 but oblique to the direftion of the Dyke. 



A new circumftance occurred here too ; this Dyke, about twenty-five 

 feet broad, had a revetement of freeftone on each fide, and was alfo twice 

 or thrice penetrated by walls of freeftonc fimilar to, and in the fame di- 



reftion 



