68 NOTES ON THE SIAMESE PROVINCES OF KOOWI, &C. 



any of the other streams. On the West side, on the other 

 hand, with an area almost three times as great to be drained, 

 the place of those babbling small streams is taken by com- 

 paratively large rivers; the Pak Chan has a drainage area of 

 600 square miles, the Linya 800 square miles, and the smaller 

 Tenasserim River has over 2,000 square miles of a drainage 

 area. These rivers on the West side, with their large drain- 

 age areas, receiving a rainfall fully double that of those smaller 

 ones on the East coast, and carrying an infinitely larger 

 volume of w T ater with its inherent properties of disintegration, 

 denudation, transportation and deposition, represent powerful 

 factors at work on the Burmese side almost absent in these 

 four Siamese Provinces. Sandy beaches form the sea- 

 board of these, with sand bars at the mouths of the streams, 

 and with patches of mangrove in the narrow marshes and 

 pools between the more recent of the old sea beaches. The 

 Champoon River, however, partaking of the rainfall as well 

 as of the character of these rivers on the West side, is sur- 

 rounded at the mouth by great mud-banks, large mangrove 

 swamps and tracts of rich alluvial soil. On the West coast 

 these evidences of deposition are extremely extensive, for the 

 islands lend a calm to the water round the mouths of the 

 rivers favourable to the settling of suspended matter, and the 

 mangrove trees stepping further and further into the water as 

 subsidence goes on highly favour further deposition among 

 the roots ; so that deposition and extension of the mangrove 

 swamps proceed pari passu. Knowing somewhat of the drain- 

 age area of a river one may roughly guess, from the extent of 

 mangrove swamp surrounding its mouth, the rainfall of the 

 district. 



Lately, at the mouth of the Krat River, on the eastern 

 shore of the Gulf of Siam, I came across some remarkable 

 evidence of the rate of deposition. The Krat River, rising 

 at the western side of the Battambong Hills, drains an area 

 of some 250 square miles, with a rainfall of probably 200 inches 

 per annum, and runs through a clay country, a considerable 

 extent of which is cultivated, so that it carries a great deal of 

 matter in suspension. In 1859 H. M. Saracen laid down the 



