AN ISLAND IN THE CHILKA LAKE. 261 



For five months in the year (April to August), the prevailing direction on the 

 neighbouring coast is S.W. or S.S.W., and this may be taken to be so also on the 

 lake. Even at other times of the year south-westerly winds are the most frequent 

 on Barkuda, but the heaviest storms are from the south-east or east. As a rule the 

 breeze, from whatever direction it may be blowing, drops considerably in the even- 

 ing and does not rise again until about 9 a.m., but in unsettled weather the wind is 

 often stronger at night. 



Structure. 



The physical structure of the island is very simple. The surface is nowhere 

 more than 30 to 40 feet above high flood-level. In the interior the rock is for the 

 most part covered with a thin layer of red soil, but on the foreshore, of which a con- 

 siderable area is exposed as the floods recede in autumn after the end of the monsoon 

 rains, it crops up on the surface round a great part of the periphery of the island, 

 and even inland there are stony and rocky areas with hardly any soil. Almost the 

 whole of the sheltered northern foreshore is sandy, the sand being of a very coarse 

 consistency and of a whitish colour, while on the east side, which is more exposed to 

 violent wave-action than the others, a good deal of sand is also present, but is mixed 

 with coarse gravel and small stones and with occasional outcrops of rock. The origin 

 of the sand on the two sides is probably different. On the north side it has accu- 

 mulated gradually owing to the currents which sweep round the island, while on the 

 east side it has been formed in situ by the breaking up of the rocks in stormy 

 weather. 



Mr. Vredenburg has favoured me with the following observations on the geolo- 

 gical formation of the island : — 



"The island appears to be roughly triangular with a straight southern coast 

 trending approximately east-w^est, an eastern coast trending approximately north 

 and south, while from the north-eastern to the western corner of the island, the 

 general trend of the coast is from north-east to south-west. 



Along or near the south coast rock is everywhere exposed in the form of an 

 abrupt low escapement. This escapement is essentially of the nature of a true scarp 

 though the structure is mostly concealed by the confused disposition of the broken 

 blocks. This breaking up of the low scarp is probably to be accounted for by wave- 

 action, which may have been more effective at a time when the relative level of the 

 water was higher than at present.' The escapement is now mostly overgrown by 

 forest. 



The eastern coast exhibits a succession of rocky promontories probably con- 

 structed by the more resisting strata, between which are embayments in which the 

 rock is concealed by detrital soil and sand. 



Along the northern or north-western coast which, in places, must more or less 

 coincide with a dip slope, the rock, with the exception of some insignificant shows 



I In stormy weather it is still more considerable than could be realized in calm weather, such as that in which 

 Mr. Vredenberg examined the rocks. — N. A . 



