288 



bounds of Magheraboy gave 200 feet ; that near the west bounds of 

 Clegnagh 210 feet. On the whole, the thickness of the limestone at 

 Ballintoy may be counted 210 feet, and this is the thickest part of it 

 that is known in Ulster. 



Fig. 3. 



Trap and Chalk at Kenbane Head. 



38. The Priest's Hole is immediately at the coast road side at the 

 white rocks, two miles east of Portrush. Looking over the road fence 

 at this place, the traveller sees the shore below, and the white cliffs, 

 through a narrow, deep hole, only a few feet in diameter. The road 

 appears to be 100 feet over the sea, and there is about 50 feet more 

 of limestone above the road, to the bottom of the basalt, in all 150 feet; 

 but the base of the limestone is not seen on the shore. It may be 200 

 feet thick here, as it is at Ballintoy. I have thus followed the eastern 

 escarpment of the chalk all the way from Balmer's Glen, near Moira, 

 to Cushendall, which runs nearly parallel to the shore for 40 miles, and 

 continued the observations on the north coast to Portrush, about 30 

 miles more. But there are two circumstances yet to be noticed that 

 bear upon the inward dip, or basin shape of the chalk formation. The 

 first of these is, that besides the immediate dip at the outcrop, in the 

 vicinity of Belfast, which is westward all the way from station No. 3, 

 at Aughnahough, to No. 8, Cave Hill, there exists a further corrobo- 

 ration of this view. An approximation to the amount of this dip may 

 be made from the following facts : — 



At Templepatrick there is a pretty extensive field of the chalk bare, 

 without the usual covering of trap, and it stands at 180 feet above sea 

 level. The eastern outcrop of it at Cave Hill is 750 feet high ; the 

 difference between these heights gives a fall westward from the outcrop 

 at Cave Hill to Templepatrick of 570 feet in 6 miles, which is 95 feet 

 in a mile, or nearly one degree. 



It is a curious coincidence that the same rate of inclination may be 

 had by taking other data — that is from the top of Divis Mountain to the 

 deepest part of the bottom of Lough ]S"eagh, gives 95 feet in a mile. 

 But, notwithstanding this, there is reason to believe that the chalk at 

 Templepatrick has been a little upheaved from the bed surrounding it. 



