1847.] 



Laccadite Islands. 



7 



Each of the islands is situated on an extensive coral shoal and 

 contains from 2 to 3 square miles superficial area. Their surface is 

 flat and no part of any of these formations is more than 10 or 15 feet 

 above the level of the sea. All round a more or less extensive 

 fringe of coral reef extends broader and more shelving on the west, 

 where the island naturally most requires protection, and narrow and 

 abrupt on the east. 



The outer edges are higher than the body of these shoals and ex- 

 tending in a semicircle at a distance of 500 yards to | of a mile 

 round the west, enclose a regularly formed lagoon, in which the water 

 is so still, that in the worst weather coir may be soaked within the 

 low water mark without danger of being washed away. The body 

 of the island is the more perfect development of the eastern and pro- 

 tected side of the coral formation.* The same feature characterizes 

 all these shoals and leads to the conjecture that they rose to the sur- 

 face in the form of circular or oval shallow basins, and that under 

 the protection of the shoal the east rim gradually developed itself 

 towards the centre and formed an island. This conjecture is 

 strengthened by the fact that in some of the islands this gradual 

 increase towards the lagoon is still going on. 



The receding tide leaves the outer edge of the reef nearly dry, and 

 the water gets out of the lagoon by two or three breaches in the 

 outer rim, sufficiently large to admit the light native craft into the 

 natural harbour, several feet deep even at low tide, which the 

 lagoon forms. 



The foundation of the soil in all these islands is a 

 stratum of coral or lime-stone, which varying from one 

 foot to one and a half foot in thickness, is seemingly above the 

 highest level of the water, and of a piece with the whole shoal, 

 stretches uniformly throughout the portion of the formation which 

 is above water. Within, this crust contains loose wet sand, and by 

 removing a few spadefuls to allow the water to accumulate a pool of 

 fresh water may be obtained in any part. All the wells, tanks and 



* According to Lieut. Wood, Anderot is an exception to this general characteristic. 

 "The other islets are situated to the leeward of their respective reefs, whereas Anderot 

 not only presents a bold front to windward, but that front is one side of the island itself 

 and not a reef as is generally the case, the coral reef on which it is based projecting to 

 leeward instead of to windward, S.W. being considered the prevalent direction of the 

 wind." 



