184 EFFECTS OF FOEEST VEGETATION ON CLIMATE. 



necessary, more or less, to the well-being of every comitry ; and 

 that many regions once fertile have become otherwise by the loss 

 or curtailment of this magnificent provision of Nature for their 

 covering." He points out that there is a remedy in "planting 

 fresh forests where none exist — (serit arhores quce alteri sceculo 

 2?rosini),''' and refers to Mr. Pox "Wilson's memoir, read before 

 the British Association, " regarding an extensive region in the 

 Orange Eiver territory of South Africa, bearing marks of 

 having been formerly well wooded, but now utterly treeless and 

 barren." 



This will be noticed hereafter. 



It has been stated by Dr. Kelly (Transactions of the Literary 

 and Historical Society of Quebec, III., part 1, p. 46), from com- 

 parison of ancient documents, that the climate of Canada has 

 not varied much for the last 200 years ; and by other writers, 

 that England in the time of the Norman Conquest, about 800 

 years ago, resembled that of Canada in its extremes of heat and 

 cold, its dense covering of forests, and its growth of vineyards 

 and accumulations of wdnter snows and ice. Grapes certainly 

 ripen now^ in the south-eastern part of England when properly 

 cared for, as I know they did on the walls and roof of my father's 

 house ; and, I believe, even as far north as Archangel, in Russia ; 

 but it is impossible to doubt that the clearing of the forests 

 which formerly covered three-fourths of the country has modi- 

 fied the climate of England, whilst a change in an opposite 

 direction has been said by Mr. Williams to have taken place by 

 the introduction of the hawthorn hedges {Craicogus oxycantlid) 

 that now universally obtain. That author says, in his book on 

 the Climate of Grreat Britain, that during sixty or seventy years 

 previous to his publication, these hedges had produced wet 

 summers. 



Perhaps this method of dealing with the subject may be con- 

 sidered too vague to carry conviction with it ; but it is only 

 within a few years past that Climatology has taken the appear- 

 ance of an exact science, and observations respecting any of the 

 elements of Meteorology — still in its infancy, and only yet par- 

 tially understood — had no existence in the distant periods to 

 which, for comparison with the present, we are called upOn partly 

 to have recourse. Moreover, all climates are merely local ; and 

 what may be strictly true of one region may have little relation 

 to the particular conditions of another. Nevertheless, there are 

 certain general facts that may be so applied, and specially in 

 such an inquiry as the present, though many of the circumstances 

 may be wanting to meet the strict objects of what is called 

 modern Science. Each country has' its own peculiar character- 

 istics, and there are many geological data to be considered in 

 relation to climate before what applies to one region especially 



