322 REPORT— 1891. 



A notice in Besearch of the 1st October, 1889, states 

 that Dr. Hamberg, of the Central Meteorological Institute of 

 Stockholm, has been detailing in a public address the results 

 of his thirteen years' experience and investigations on the in- 

 fluence of forests upon climate. These were carried on at 

 numerous stations — some on free open land, some on forest- 

 clearings, and some in the depths of woods — and related more 

 especially to temperature, humidity of air, and rainfall. He 

 found that temperature was more equable under trees than on 

 free land, and on free land than in clearings ; and that, while 

 forests afforded shelter against cold and cutting winds, they 

 did harm on the whole in respect to the sun's heat by de- 

 priving the earth of it, and fostering frost through lowering the 

 temperature on the ground on clear nights. x\s regards the 

 moisture of the air and the rainfall, his researches went to show 

 that in Sweden, at all events, forests are simply without in- 

 fluence. In Gothland, e.g., the new forests, presumably ex- 

 tensive, had not increased the rainfall in the least. He 

 concluded that climate rested on a more solid basis than that 

 of forests, and that forests deserved preservation for more 

 weighty reasons than their influence on climate. At the meet- 

 ing where this address was given, Baron von Kroemer agreed 

 with the views of Dr. Hamberg, and went so much further as 

 to say that even as regards protection trees were not always 

 desirable, for in Scania, e.g., corn dried much more quickly 

 after rain on free land than in clearings. There is no doubt 

 that in a cold country like Sweden the beneficial effects of 

 forests would be less than in a tropical country like Ceylon, 

 e.g., where Colonel Clarke, after many years of observations, 

 came to the conclusion that "forests make climate more 

 equable, increase the relative humidity of the air, and perhaps 

 increase the rainfall," and also regulate the water-suppl}-, 

 making springs more sustained and rivers more continuous ; 

 gi\'ing besides protection against strong winds, and preventing 

 the soil from being washed away by heavy rains {Nature, 

 18th October, 1888). This is pithy testimony given by an 

 authority who commands attention ; but there is nothing in 

 that testimony which militates against my views, herein 

 expressed. 



The proposition which I have endeavoured to establish is 

 one which some people will be disposed to regard as so self- 

 evident as to need no demonstration. It is one which, never- 

 theless, is frequently lost sight of when the relationship betw"een 

 rainfall and forest is discussed ; and it can be maintained quite 

 consistently by those who hold, as I do, that the wholesale 

 destruction of the forests of a country must be, as a rule, pre- 

 judicial in various ways to its future interests ; though in the 

 process of settlement such destruction, or at all events a large 



