Lieut. Nelson on the Geology of the Bermudas. 



Fig. 13. Serpuline Reef and Section, near Elbow Bay. 



117 



Diluvial Agency. 

 External Evidences. — Pig. 2, Plate VI. illustrates the true forms of the 

 ground taken at points in the islands without any especial selection. The 

 lines are surveys of horizontal contours^ traced by a spirit level, at given 

 heights. An eye accustomed to such topographical considerations, will, I 

 think, recognise a similarity to the results which in other parts of the world 

 have been referred to the sweeping action of a huge body of water. 



I cannot but suppose that such singular lines of islets, as those terminating Long-bird island, 

 those in Crow-lane Harbour, the ' Stags,' near Crawl Point, &c., are most naturally accounted for 

 by the exertion of such a force ; as the strata in these little spots are nearly always horizontal, 

 and evidently frusta of a more extensive formation. 



It has just been stated, that reefs generally collect close, and parallel to any shore as a nucleus. 

 Throughout the whole extent of the south side of the group, there is exactly such a general 

 conformity to the shore in the Serpuline reefs, which, nevertheless, vary in their distance from 

 it, between fifty and five hundred yards. Its contour-like resemblance (Map, Plate VI.) to a 

 former coast line is very striking, especially when the numerous coincidences are duly considered 

 between the present positions of its fragments, and those of the more or less truncated hills along 

 the sea side ; at the original foot of which they would generally lie, were the slopes of the ground 

 restored. 



Such circumstances can however yield only probable evidence. To convert them into positive 

 testimony we should require that points of hard persistent rock should appear through this reef 

 at such irregular distances as would be suggested by the variable density of the Bermuda stone ; 

 and we might likewise expect that, occasionally, the summits of these peaks should exhibit a 

 stratified appearance. 



We have abundance of such witnesses in what are called ' Boilers,' ' Breakers,' &c., or rock 

 heads, which have served as points of aggregation to the reefs around them. Such are the 

 Boilers on the continuation of the line of the point, at the west end of Great Turtle Bay ; those in 

 the centre of Common Landing Bay; the long and dangerous chain of about thirty sunken 

 rocks, between the Bear Boiler and the South-West Breaker ; the ' Stags,' between Ireland island 

 and Spanish Point, &c. &c. From accounts received, I have reason to suppose that such are to 

 be found all round the North Reef; but at one place I am certain of it, the * North Rock,' or as 

 the old French maps used to call it, " La petite Bermuda;" and it is to be observed that the 



