146 EFFECTS OF FORESTS ON MOISTURE. 



set fire to the woods, and produced a conflagration which lasted seven 

 days." 



Dr Graham says, — " The forests of Madeira have been continually 

 receding with the increase of fuel requirement, and the replanting of 

 the land thus laid waste has been long and culpably neglected. 

 Recently, however, the introduction of the pine tree has to a very 

 great extent stemmed the progress of reckless destruction. The pine 

 grows easily and rapidly, occupying lands ill-suited to other kinds of 

 cultivation." And in another couneution he says, — " The recession 

 of nature's woods has been in late years compensated by the advance 

 of the introduced species." 



He reports his observations on the arrest of the water of fogs and 

 clouds by the leaves of the coniferse, and other trees, which act almost 

 like a sieve, draining it out ; and he remarks, " when the hills were 

 completely wooded, at the time of the colonization, it is quite 

 probable that the humid mists, continually passing over the moun- 

 tains, were intercepted, and that the rivers which now, soon after 

 rain, dwindle down to tiny streams were then more constantly full." 

 And he further remarks : — " On the eastern side of the basin of 

 Funchal, the upper lands have been almost entirely cleared of trees. 

 The rain water descends impetuously in a torrent, leaving a tiny 

 stream, which flows steadily so long as the sky is overcast, but 

 ceases altogether after one day of sunshine. I do nut think the rains 

 are now heavier or more fitful than in former times ; but there are 

 now no woods on the south side to restrain the drops, which unite to 

 denude the rocks of their soil, and to form the mighty torrents 

 witnessed every winter. I do not doubt that the planting of trees in 

 the villages at the head of the main ravines would lead rapidly to a 

 nearly constant supply of water in a region where it would be useful.' 

 The facts reported and the conclusions drawn from them are all in 

 accordance with what has been reported in regard to St Helena and 

 Ascension. 



By Blanqui, in his Voyage en Bulgarie, already cited, it is alleged 

 that " the terrible droughts which desolate the Cape Verd Islands 

 must be attributed to the destruction of the forests." And he says 

 that, " in Egypt, recent plantations have caused rains which hitherto 

 were almost unknown." 



I have repeatedly met with a reference in different forms to 

 observations which have been made, or are alleged to have been 

 made, in Alexandria and Egypt, in accordance with those which have 



