lOO [Proc. B. N. F. C, 



distance from town being the chief drawback. Searching for 

 fossils in the chalk is rather tedious, but several specimens were 

 secured — amongst others Rhynchonella, Pecten, &c., but none 

 of any great rarity. Whilst in the quarry the old question 

 was discussed again as to the cause which has produced the 

 difference between the Chalk of the South of England and the 

 North of Ireland. Both are part of the same geological forma- 

 tion, both contain the same fossils, and are precisely identical 

 in chemical composition, but whilst the English Chalk is soft 

 and friable, the Irish is extremely hard, brittle, and splintery. 

 Neither the theory of heat from the superincumbent Basalt, 

 which was once molten lava, nor that of pressure from the 

 weight and mass of the same, nor of heat and pressure com- 

 bined, seems altogether satisfactorily to explain it. Have these 

 theories ever been put to the test in the laboratory ? From 

 the quarries the distance is short to the top of the hill, 1230 

 feet above the sea, the botanists of the party picking up on the 

 way several specimens of the minute and somewhat rare fern, 

 the moonwort {Botrychium lunaria), which, as it dies down in 

 the autumn, can only be easily found during the months of 

 June and July. From the cairn, on the summit, the broad 

 extent of Lough Neagh was seen glittering in the west ; the 

 Mourne Mountains were obscured by a flying rain cloud, whilst 

 emerging from another squall on the north the conical top of 

 Slemish came into view. The strong breeze rendered a long 

 stay the reverse of pleasant, and the party were soon descending 

 towards the large basaltic quarry on the eastern face of the hill, 

 near which the dynamite used in the locality is stored. In 

 this quarry, the basaltic blocks of which are rudely columnar, 

 an excellent road metal is obtained, and some of the stones are 

 squared into sills, steps, and setts for paving. This is the stone 

 which an unscientific correspondent of the papers described 

 some time ago as " granite," the discovery of which was to open 

 up another source of industry to the artisans of Belfast. Though 

 granite and basalt are both igneous rocks, yet the circumstances 

 of their origin, their mineralogical characters, and the positions 



