ON THE DESTRUCTION OF TROPICAL, FORESTS. 101 



this circumstance we may attribute the difference in the falls of rain at these 

 stations." 



Assistant-surgeon Balfour, in his notes on this subject, has well remarked, 

 ' that the observations of scientific men support the belief that a mutual re- 

 action goes on between these two physical agents, and that the presence of 

 trees greatly adds to the supply of water and feeds the running streams.' 

 The instance of a single district losing its supply of water on being cleared 

 of forest, and regaining it again when restored to its original state, would not 

 alone establish more than strong presumption that the clearing of the forest 

 and the loss of rain followed each other as cause and effect ; but the Ho- 

 nourable Court of Directors, in their circular, mention that this is not 

 uncommon in America. 



On the subject of springs, Assistant-surgeon Balfour quotes from Jameson's 

 Edinburgh Philosophical Journal, a very remarkable instance at Popayan in 

 Peru, of a district losing its supply of water from the clearance of the forest : — 

 " Two instances corroborative of the above have come under my own obser- 

 vation, and happened to friends in different parts of the country engaged in 

 coffee-planting. The first happened in a range of hills south-east of Ban- 

 galore, at a coffee plantation now called Glenmore, in ihe Debenaicottah 

 talook of the Salem district. The proprietor, when preparing ground for a 

 coffee garden which was watered by an excellent spring, was warned by the 

 natives not to clear away the trees in the immediate neighbourhood of his 

 spring ; he disregarded their warning, cut down the trees, and lost his stream 

 of water. The other instance happened at the village of Hoolhully, about 

 eight miles distant from the head of the new ghaut in M ungerabad ; 1 wrote 

 to the gentleman to whom it occurred, who answered as follows : — ' The 

 cutting down trees and clearing jungle on the sides of ravines in the close 

 vicinity of springs, undoubtedly has a great effect in diminishing the quan- 

 tity of water. I found it so in one or two instances in ravines I had cleared 

 for planting ; at one place where I had a nursery, which I used to water by 

 turning a water-course from the spring, I found that since I cleared up the 

 sides of the ravine in which the spring is (for planting), I have not anything 

 like the quantity of Avater I had before the shade was cleared. I presume 

 this is to be accounted for by the increased action of the air and sun ; at any 

 rate the natives about here are of that opinion. I leave the cause, however, 

 to be settled by more scientific men than myself; that the effect is so, there 

 is no doubt. A ravine close to the bungalo where there is a spring, a few 

 years ago I cleared for planting, and found the water decrease in like manner ; 

 but the coffee-trees dying away, and the place being too small for a plan- 

 tation, I did not renew them, but allowed the jungle to grow up again, since 

 which the stream has nearly regained its former size.' " 



The superintendent of Nuggur writes, " that springs of water shaded by 

 trees, almost invariably dry up on the trees being cleared away. This has 

 been observed on the Neilgherry Hills and many other woody districts." In 

 what way trees influence springs it is impossible to say ; that they do so 

 seems to be established, as also that they condense and attract vapoui*. 



" This effect of trees in mitigating the intensity of tropical heat, has also 

 been alluded to by the present superintendent of forests in our western pre- 

 sidency, who mentions that in the southern districts of Guzerat the vicinity 

 of the sea and the proximity of the mountain tracts covered with jungle, tend 

 to render the climate more mild, and the temperature throughout the year 

 more equable than is the case in the other parts of the province. Further in- 

 land, and in the immediate vicinity of the hills, the heat is greatei', and in both 

 situations the humid and loaded atmosphere in the S.W. monsoon is often pain- 



