BIT XOYER FLIXT FLAKES. 49 



Specimens illustratiYe of the manufacture of gun-flints explain 

 most fully the force of the arguments brought forward to prove the 

 mechanical origin of these " drift" flint flakes. 



These worked flint flakes occur in two very distinct formations — 

 the most ancient that of the marine drift-sand and gravel which skirts 

 the shores of Belfast and Larne Loughs, in the co. iVntrim, and the 

 coast from Holywood to Donaghader, in the co. Down — its maximum 

 elevation being about 20 feet above the level of high water. All the 

 flakes from this deposit are of the ruder forms, and their surfaces are 

 more or less oxidized or rendered white : and though they are imbedded 

 in what was well-washed or rolled sea-drift, the chippings round 

 their sides and angles are remarkably sharp — thus proving that they 

 did not suffer much attrition after their submergence, and before 

 the elevation of the marine-drift to its present subaerial position. 



The more recent flakes are found in the subsoil clay, at all ele- 

 vations up to 600 feet or so, on the northern slopes of the Cave Hill 

 at Belfast, the commons of Carrickfergus, and the lofty ground around 

 Larne Lough, including that of Island Magee. 



These flint flakes sometimes occur in groups, and so abundantly 

 that hundreds of them can be collected over a surface of 50 square 

 yards, and they are all more or less characterized by a comparatively 

 fresh look ; but they all possess that porcellanous glaze which time 

 alone can give to the surface of a fractured flint. 



At one locality on the east coast of Island Magee, at the south 

 end of " the Jobbins," I found a hoard of these subsoil flakes, and 

 on the west shore of Larne Lough, at Ballybig, a similar collection 

 of the older variety of these implements in the marine-drift. Here 

 they were accompanied by large irregularly shaped lumps of flint, 

 on one of the edges of which was preserved the original rounded 

 surface of the nodule, evidently thus left to fit them to the hand, and 

 thus allow of their being used as hammers to fabricate the required 

 flake of flint. 



In some rare instances the subsoil flakes, when originally of the 

 arrow-headed type, present near the bulb of concussion (which then 

 becomes the base of the implement) the flint- chijDping necessary to 

 form the wing of a perfect arrow- or javelin-head. Elakes of this 

 variety are most usually found in the interior of the co. Antrim, as 

 at Toome Bridge and near Moira. 



The Eev. Dr. M'llwaine, of Belfast, has kindly allowed me to make 

 some sketches from flint flakes of this character in his collection ; and 

 I now beg to present them to the portfolio of the Geological Society, 

 to aid in making as complete as possible the small collection of flint 

 flakes which accompany these remarks *. In some rare instances deep 

 side-notches are observed on the more ancient oxidized flakes from 

 the marine drift ; but their position is variable. 



So far as our present information leads us, I believe we can 

 arrive at the following conclusions with reference to the origin and 

 mode of occurrence of these worked flint flakes : — 



During the formation of our present raised sea-beaches, the in- 

 * Deposited in the Society's Collection. 



VOL. XXV. PART I, E 



