2 THE NATUEALIST IN BEEMUDA. 



It was written by Lieut, (now Col.) Nelson, of the Eoyd 

 Engineers ; from which, as it has been acknowledged to 

 be the best treatise ever produced on the subject, we 

 cannot do better than glean that portion which is suited to 

 our purpose, in order to shew to what particular causes the 

 Bermudas owe their origin. 



This of&cer informs us that the whole of the islands 

 are composed of a calcareous sandstone, derived from com- 

 minuted shells and corals, varying in texture from loose 

 sand to a hard compact limestone ; the varieties being irre- 

 gularly associated, and without any order of super-position. 

 From the saddle-shaped sections observable throughout the 

 islands, he concludes that the strata have evidently been 

 accumulated round numerous and contiguous centres. The 

 bottom of the basin consists of coral reefs (which do not 

 appear above low-water mark, except at spring-tides,) and 

 calcareous sand ; the latter being associa,ted with consider- 

 able tracts of chalky ground, in which the best anchorages 

 are found. He met with this chalk, likewise, as an occa- 

 sional constituent of the rock, lying irregularly among its 

 beds in a soft state, or lining caverns, but seldom exceeding 

 a few square yards in surface, and a few inches in depth.* 

 The only minerals noticed were small pieces of oxide of 

 iron, of very questionable origin ; menaccanite, found near 

 the Ferry, between St. George's Island, and Bermuda or 

 Main Island ; arragonite (?) ; and a minute quantity of 

 manganese in the red earth. 



* The Boyal Engineers claim to be the first to give any distinct clue to 

 the origin of chalk ; though within but a few months they were followed by 

 Darwin and Lonsdale, on other and perfectly independent grounds. See 

 Bahama Paper, Geol. Soc. Transactions. By Colonel Nelson. 



