TEEES AS SHELTER TO GEOUND TO THE LEEWAED. 161 



the west, to the mild breezes of the sea. Hence a decrease of the 

 cold of winter. If a similar forest were to be cleared on the 

 eastern border of France, the glacial east wind would prevail with 

 sreater strength, and the winters would become more severe. 

 Thus the removal of a belt of wood would produce opposite 

 effects in the two regions." * 



This opinion receives confirmation from an observation of Dr. 

 Dwight, who remarks in reference to the woods of Kew Eng- 

 land : " Another effect of removing the forest will be the free 

 passage of the winds, and among them of the southern winds, 

 over the surface. This, I think, has been an increasing fact within 

 mj own remembrance. As the cultivation of the country has ex- 

 tended farther to the north, the winds from the south have reached 

 distances more remote from the ocean, and imparted their warmth 

 frequently, and in such degrees as, forty years since, were in the 

 same places very httle known. This fact, also, contributes to 

 lengthen the summer and to shorten the winter half of the 

 year." f 



It is thought in Italy tliat the clearing of the Apennines has 

 very materially affected the chmate of the valley of the Po. It 

 is asserted in Le Alpi che cingono V Italia that : " In consequence 

 of the felling of the woods on the Apennines, the sirocco prevails 

 greatly on the right bank of the Po, in the Parmesan territory 

 and in a part of Lombardy ; it injures the harvests and the vine- 

 yards, and sometimes ruins the crops of the season. To the same 

 cause many ascribe the meteorological changes in the precincts of 

 Modena and of Reggio. In the communes of these districts, 

 where formerly straw roofs resisted the force of the winds, tiles 

 are now hardly sufficient; in others, where tiles answered for 

 roofs, large slabs of stone are now ineffectual; and in many 

 neighboring communes the grapes and the grain are swept off by 

 the blasts of the south and south-west winds." 



According to the same authority, the pinery of Porto, near 

 Pavenna — wliich is twenty miles long, and is one of the oldest 

 pine woods in Italy — having been replanted with resinous trees 



* BECQUEREii, Des Glimats, etc., Discoura Prelim., vi. 

 f Travels, i., p. 61. 



