14 THE GEOLOGY OF BERMUDA. 



All the rock in the interior of tbe islands, and all tlie rock which is 

 much elevated above the water level, is drift-rock. Indeed, substan- 

 tially the whole mass of the rock visible in the islands is drift-rock. 

 Probably along the greater i)art of the shore drift-rock comes down to 

 the water's edge, no other rock being visible. I was not able to exam- 

 ine the whole of the coast, but I am confident that drift-rock comes 

 down to the water's edge along the north shore of the Main Island from 

 Spanish Point to the Flats and beyond, along a part at least of the 

 north shore of St. George's, around a considerable part, if not the whole, 

 of the circuit of Harrington Sound and Castle Harbor, around the head 

 of Hamilton Harbor, and in many places even along the south shore of 

 the Main Island — the region of the coast in which the beach -rock is 

 best exhibited. North Eock, at least in its upper part, is formed of 

 drift-rock, as is shown by the high dip of its lamination.* This char- 

 acter of the rock is well shown in the beautiful photograph taken by 

 Mr. J. R. Heyl, of Hamilton. The drift-rock is usually very soft, so that 

 it is quarried out for building j^urposes by means of a peculiar long- 

 handled chisel, in large blocks, which are readily sawn into pieces of 

 such size and shape as may be wanted. Most of the houses in Bermuda 

 are built of this exceedingly friable stone. Even the roofs are covered 

 with the same material sawn into thin slabs. This stone, covered with 

 a coat of whitewash, is suflQciently durable for ordinary buildings in the 

 Bermudian climate. Exi^osed to the frosts of a New England winter, 

 it would of course crumble very rapidly. Although the drift-rock is 

 generally quite soft and friable, it is sometimes very firmly consolidated 

 and of a subcrystalline texture. This hard rock is quarried like any 

 ancient limestone or marble, and has been used in the construction of 

 the fortifications and other government works. The quarries at Payn- 

 ter's Vale and on Ireland Island are in such a hard drift-rock. The 

 quarry of the Royal Engineers, near Elbow Bay, appears to be in beach- 

 rock. It would be a curious question, what are the precise conditions 

 which have determined the varying action of the rains on these accu- 

 mulations of coral sand. While in some localities the sands have been 

 merely washed away and dissolved, in others the grains have been, by 

 the action of the same rains, cemented firmly together, until the rock 

 has assumed a sub-stalagmitic texture, as at Paynter's Vale. 



The usual softness of this drift-rock has made it a matter of small 

 labor and expense to secure easy grades on most of the roads in the 



* Thomson, op. cit., Vol. I., p. 296. 



