THE LAGOON 187 



with ; for the advance of vegetation is the surest way of winning 

 dry land from the silt regions. In the reclaiming of the 

 lagoon shallows a grass {Lcftums rcpens) plays a great part, 

 for it binds the shifting sand firmly with its long trailing roots, 

 and makes firm dry land out of the useless shallows. 



In 1827, when the permanent settlers first arrived in the 

 islands, the silting of the southern portion of the lagoon was 

 not nearly so far advanced as it is to-day. The schooner which 

 the islanders made for their use was actually built in Pulu 

 Atas, and launched from it ; and it sailed in and out from the 

 settlement on the island to keep up the necessary traffic of 

 the atoll. Before ten years had passed, however, the silting of 

 the southern end of the lagoon had proceeded so far that the 

 boat channel became obliterated, and schooner traffic with the 

 settlement was cut off. It was for this reason that the site of 

 the settlement was moved to Pulu Selma, the island which it still 

 occupies, situated in the northern deeper half of the lagoon. 

 It would appear that the southern anchorage has never been 

 used for any other craft than the island-built schooner, for 

 ever since the atoll has been charted the safe anchorage has 

 been given as Port Refuge in the lagoon off Pulu Tikus, or 

 else without the lagoon altogether in the gap between Pulu 

 Tikus and Pulu Luar. 



Although the whole story of the southern part of the 

 lagoon discloses a steady progress of the conversion of a coral- 

 studded stretch of water into sand flats, still, at any one point, 

 some indications might be seen, from time to time, which would 

 seem to contradict the general trend of the process. Beach sand 

 has been seen to be the fluctuating capital of the islands and 

 of the beaches : and, in exactly the same way, the silt sand of 

 the lagoon is the ever-varying factor in the ceaseless minor 

 variations, which are always going on in some part of the whole 

 extent of the lagoon. Sand spits and shallows wax and wane ; 

 banks are piled up, and then soon after scoured away, but in 

 the manner of these changes there is no general influence upon 

 the atoll structure as a whole, and purely local conditions 

 determine the balance of the processes at work in any given 



