126 EFFECTS OF FORESTS ON MOISTURE. 



"That the rainfall in that island during the five years 1862-66 was 

 considerably le^s than during any previous five years of the whole 

 period since 1853 ; " — " that during the first five years, from 1853- 

 57, the relative humidity of the air was 72'1, whilst during the last 

 five years, 1862-66, it was only 68*2 ;" — " that the vapour pressure, 

 which in the earlier of these quinquennials was '657, had fallen 

 during the latter given quinquennial to •638." 



Notwithstanding these facts, he says : — " In no former year of the 

 period of fourteen years did such floods occur as in 1861 and 1866, 

 or such severe droughts as in 1865 and 1866." And to account for 

 these facts, he says : — ■" That the decrease of rainfall, humidity, 

 and vapour pressure, and the occurrence of floods and droughty may 

 in some measure be due to the cutting down of the forests, which 

 commenced on an extensive scale about 1852, was vigorously carried 

 on till 1862, and is being still prosecuted, though to a smaller 

 extent." 



One chief cause of the cutting down of the forests in the Mauritius, 

 Mr Meldrum states thus : — " Proprietors of forests in high and 

 remote parts of the island, where the climate was as yet too damp 

 and rainy for the sugar-cane, engaged in the work because they 

 believed that their land would thereby become more fit for such 

 crops ; for it was very well known that the climate became drier in 

 proportion as the forests were cut down. Upon the whole, I think, 

 at least 70,000 acres, or about one-sixth of the entire area of the 

 island, have been denuded of forests since 1852, and that, too, on the 

 central and elevated parts of the island, at or near the sources of the 

 rivers." 



He points out how, by the lowering of lakes, and the complete 

 desiccation of others, malaria resulted, and a deadly epidemic. And 

 the remedy which he suggests is, " to restoi'e, as far as practicable, 

 certain portions of the forests of which this once salubrious and 

 beautiful island has been deprived." 



In 1871, a report was issued by Dr H. Rogers, of Mauritius, " On 

 the Eff'ects of the Cutting down of Forests on the Climate and Health 

 of Mauritius." This report I have not seen ; but in a lecture on Forest 

 Culture in its relation to industrial pursuits, delivered in Melbourne 

 on the 22d June, of that year, by Baron von Miiller, Government 

 Botanist in Victoria, there was given the following resume of its 

 contents, with the remarks which follow : So late as 1861 the Island 

 was resorted to by invalids from India, as the " pearl" of the Indian 

 Ocean — it being then one mass of verdure. But when the forests 



