EFFECTS OF FOEEST VEGETATION 01^ CLIMATE. 207 



To complete the evidence from that portion of India alluded to 

 by Sir Wm. Denison and Dr. Bidie, we must, in conclusion, turn 

 to the valuable dissertation of Mr. Gr. S. Markham, F. S. A., 

 Secretary to the Eoyal Geographical Society, " On the Effects 

 of the JDestruction of Forests in the Western Ghauts of India on 

 the Water Supply'''' (published in the Society's Journal, vol. 

 XXXYI., 1866). 



The author introduces the district of Coorg, but does not con- 

 fine himself to it. He says : " The destruction of forests has 

 been one of the chief agents in effecting changes in the earth's 

 surface, and the best methods of counteracting evil which may be 

 caused by these extensive clearings is one of the most important 

 questions that occupy the attention of physical geographers." 

 This agent is now at work in the Western Ghauts of India, those 

 rich and beautiful mountain-districts forming the backbone of 

 the Indian Peninsula, and containing the sources of a water- 

 supply on which the prosperity — indeed, the very existence — of 

 millions depends." It is of an area of fully 7,000 square miles, 

 to which the above remark refers ; and it includes Wynaad 

 plateau, which to the south borders Coorg, and is about 50 miles 

 from the feet of the Neilgherries. 



Wynaad is drained to the eastward by rivers that join the Cau- 

 very ; these are fordable in the dry season, and become furious 

 torrents, 200 feet wide, rising thirty feet, dashing along with 

 tangled branches and uprooted trees. In these respects they 

 form a paraflel to the rivers of Australia that descend from 

 similar average height of 3,000 feet ; the rocks are hornblendic 

 granite and syenite, with basalt and quartz. 



Coffee -planting commenced in ISiO, and in 1866 there were 

 192 estates, covering 14,613 acres. 



Passing the gap, mentioned by Sir "W. Denison, in which the 

 railway runs, rise "the glorious AnamuUays and Pulneys, and 

 the hills of Travancore, and these run on with breaks and peaks, 

 under various designations, to Cape Comorin. The Pulneys were 

 described by Mr. Markham, in his " Travels in Peru and India." 

 The Anamullays were described by Dr. Cleghorn. 



The rainfall on the Ghauts which is given above as about 112 

 inches, according to Mr. Markham decreases towards the south 

 from 248 inches per annum at Mahabuleshwa,r, near Bombay, to 

 65 at Trivanderum, and to 30 inches at Cape Comorin. 



At Mercara, at the centre of Coorg, it is 145 inches ; at Nuggur, 

 about 100 ; the mean of Nuggur, Coorg, Wynaad, and the Koon- 

 dahs " receiving the whole force of the monsoon" have a rainfall 

 of 200 inches ; the aspects giving at Chumbra hill to the west 

 186 inches, and a few miles to the eastward 154. 



On the highest peak of the Neilgherries, from 1847 to 1865, 

 the average annual fall vv^as 86"13 inches, the maximum being 



