been the case with the Maldivas; for we have seen that the islets are
placed on the eastern or south-eastern sides, whilst the breaches in the
reef occur indifferently on any side, where protected by an opposite atoll.
The reef being more continuous on the outer and more exposed sides of those
atolls which stand near each other, accords with the fact, that the reef of
the southern atolls is more continuous than that of the northern ones; for
the former, as I am informed by Captain Moresby, are more constantly
exposed than the northern atolls to a heavy surf.

The date of the first formation of some of the islets in this Archipelago
is known to the inhabitants; on the other hand, several islets, and even
some of those which are believed to be very old, are now fast wearing away.
The work of destruction has, in some instances, been completed in ten
years. Captain Moresby found on one water-washed reef the marks of wells
and graves, which were excavated when it supported an islet. In South
Nillandoo atoll, the natives say that three of the islets were formerly
larger: in North Nillandoo there is one now being washed away; and in this
latter atoll Lieutenant Prentice found a reef, about six hundred yards in
diameter, which the natives positively affirmed was lately an island
covered with cocoa-nut trees. It is now only partially dry at low water
spring-tides, and is (in Lieutenant Prentice's words) "entirely covered
with live coral and madrepore." In the northern part, also, of the Maldiva
Archipelago and in the Chagos group, it is known that some of the islets
are disappearing. The natives attribute these effects to variations in the
currents of the sea. For my own part I cannot avoid suspecting that there
must be some further cause, which gives rise to such a cycle of change in
the action of the currents of the great and open ocean.

Several of the atolls in this Archipelago are so related to each other in
form and position, that at the first glance one is led to suspect that they