300 . THE OCEAN, 



increase the soil, ?nd prepare it for the reception of accidental roots, 

 branches, and seed, ca-^t up by the waves, or brought thither by 

 birds. Thus Islands are formed : the leaves and rotten branches 

 intermixing with the sand, form in time a light black mould, of 

 which in general these islands consist, more sandy as less woody ; 

 and when full of large trees, with a greater proportion of mould. 

 Cocoa nuts, continuing long in the sea without losing their vegeta- 

 tive powers, are commonly to be found in such islands; particu- 

 larly as they are adapted to all soils, whether sandy, rich, or 

 rocky. 



The violence of the waves, within the tropics, must generally be 

 directed to two points, according to the monsoons. Hence the 

 islands formed from coral banks, must be long and narrow, and lie 

 nearly in a meridional direction. For even >upposing the banks to 

 be round, as they seldom are when large, the sea, meeting most re. 

 sistance in the middle, mu>t heave nu f.ie matter in greater quanti- 

 ties there than towards the extren:i ies : ami, by the same rule, the 

 en;ls will generally be open, or at least lowest. They will also 

 commonly have soundings there, as the remains of I he banks, not 

 undated, will be under water. Whtre *ne coral banks are not 

 exposed to the common n.ousoon, they will afkr their direction ; 

 and be either round, or extend in the parallel, or be of irregular 

 forms, according to accidental circumstances. 



The interior parts of these islands, being sea, sometimes form 

 harbours cap-able of receiving vessels of some burthen, and Mr. D. 

 believes always abound greatly with fish ; and such as he has seen, 

 with turtle- grass and other sea-plants, particularly one species, 

 called by the Sooloos gamm,e, which grows in little globules, and 

 is somewhat pungent as well as acid to the taste. It need not be 

 repeated that the ends of those islands, only, are the places to ex- 

 pect soundings : and they commonly have a shallow spit running 

 out from each point. Abdul Roobin's observation points out an. 

 other circumstance, which may be useful to navigators : by consi. 

 deration of the winds to which any islands are most exposed, to 

 form a probable conjecture which side has deepest water; and from 

 a view which side has the shoals, an idea may lie formed which winds 

 rage with most violence. 



[Thomson. Phil. Trams. Abr, Vol. XIL~\ 



