ON THE GEOLOGV OF BARBADOS. 201 



time slowh' rising, and that none of the phenomena which they 

 exhibit are in aijy way due to movements of subsidence. 



Tlie exposed surface of a fringing coral-reef has so often been 

 described that we do not propose to give any account of this as[)ect 

 of the reefs, for, after all, little can be learnt from such exposures 

 as to their mode of growth. Less attention has been paid to the 

 submarine prohles of the outer slopes of such reefs and to the deptlis 

 to which coral-growths extend beneath the waters of the sea. We 

 offer some remarks on these points, our information being chiefly 

 derived from the large Admiralty map of the island on a scale of 

 3g inches to a mile. In most cases personal exploration would be 

 necessary, but the soundings on this map are so multiplied that it is 

 easy to plot a profile of the seaward slope from any point on the 

 coast of the island, and the records of the nature of the bottom are 

 sufficiently numerous to yield some important inferences when 

 checked by such information as we could obtain regarding the nature 

 of the coral-growths. 



Coral-reefs are found all round the island except off a portion of 

 the north-east coast fronting the Scotland District. A few patches 

 of coral occur near the shore north-west of Consett's Bay, but the 

 continuous reefs cease oj^posite Bath estate, and from there to the 

 Landlock or Corbet's Bay all soundings over 5 fathoms show sand or 

 mud. The growth of coral along the east coast as far as Consett's Bay 

 proves that the absence of reefs farther north is not to be attributed 

 to the force of the surf which breaks on this coast, for all parts of it 

 are equally exposed. 



We have little doubt that the absence of coral along the tract 

 above indicated is due to frequent invasions of muddy water, for 

 after heavy rains the watercourses w^hich drain the JScotland District 

 are converted into torrents that pour tons of muddy water into the 

 sea and discolour the sea-water for a distance of a quarter to half a 

 mile from the shore. After describing one of these sudden floods, 

 Mr. J. H. S. Moxley* says: — "The effect of the freshet upon the 

 colour of the sea was much greater than even those who had seen, 

 its volume could have supposed. The dazzling whiteness of the 

 foam of the breakers was changed in the first hour of the violence 

 of the torrent to an inky hue, and afterwards to a sullen mud-colour 

 which remained for two or three days, but growing gradually clearer, 

 while an unpleasant earthy odour arose from the sea-shore, strewn 

 as it was with the debris brought down by the flood." 



Such floods, even if they occurred only once a year, would be 

 quite sufficient to prevent the growth of coral, though the constant 

 discharge of clear and pure fresh water which takes place along the 

 western coast does not seem to interfere at all with the coral- 

 growths, except where it produces a sand-moving current. 



. We will now deal with the submarine contours round the island, 

 and commence at the place above mentioned opposite Bath estate on 

 the eastern coast. Along a line drawn out to sea due X.E. from 



* ' Guide to Barbados,* p. 107 : Sampson Low & Co. 



