APPENDIX III. 



ON THE DISTRIBUTION OF THE RAINFALL 

 IN CEYLON. 



With a Map showing the Average Annual Rainfall. 

 By F. Lewis, Esq., of the Forest Department. 



The island of Ceylon lies to the South-east of the Southern 

 extremity of the great peninsula of India, and is situated between 

 North Latitude 5°53' and 9° 51/ and East Longitude 79°42'and 

 8i° 55'. Its total area is about 25,360 square miles, or, roughly, 

 one sixth less than the area of Ireland. The greatest length and 

 extreme breadth of Ceylon are 271 and 137 miles, respectively. 

 From the Indian coast the island is divided only by a narrow strip 

 of water too shallow for our large ocean steamers to cross, so that 

 vessels bound for the Eastern ports of India are obliged to pass to 

 the South of Ceylon. 



Although Ceylon has not been entirely free from those great 

 convulsions of the earth which have so strikingly affected Java and 

 neighbouring islands, it must, nevertheless, be regarded as practically 

 outside volcanic action, and beyond the limits of hurricanes. 

 Cyclonic storms have at long intervals visited the country, but none 

 of such destructive severity as to affect the prosperity of the island. 



The prevailing monsoons are the N.E. and S.W., during which 

 the vegetation of the country passes from rest to activity. 



The rainfall is heaviest in the immediate neighbourhood of 

 Adam's Peak, and, speaking generally, diminishes towards the North- 

 west and South-east. Dividing the island into zones, according to 

 the average amount of precipitation, these may be conveniently 

 classified as follows : — 



(1) The driest zone — under 50 inches of rain per annum — 

 consists of two rather narrow strips ; one, starting from the extreme 

 northern point of the island, runs for about 100 miles along the 

 North-west coast ; the other starts from near the Southern extremity 

 and runs along the South-east coast to near Batticaloa Lake. 



(2) The zone of 50-75 inches is enclosed between the two 

 above-mentioned strips, and includes also the whole North-eastern 

 sea-board (from Batticaloa Lake). This zone comprises the largest 

 area of the country. 



(3) Enclosed within the crescent formed by the last district is 

 the zone of 75-100 inches, lying roughly along the outside limit of 

 the hill country, this zone forming a sort of elongated horse-shoe 

 band of which the two horns are situated at Colombo and Galle- 



