260 RELATION OF FORESTS TO 



fiill. That even a much lower riflge t.lian the Andes may intercept 

 the whole muisture of the atiaoi[)'aerj is proved by a weU ktiowa 

 phenomenon in India, whea the G^Miits, a cliain only SuOO or 4030 

 feet high, d.vide samner frotu winter, aa it is called: that is, they 

 have copious ruins on their windward side, while on the other the 

 weather remains clear and dry ; and the rains regularly change froai 

 the west side to the east wiih the monsoons. 



" In the region heyoud the 30th parallel this effect will be reversed. 

 The Andes will in this case serve as a screen to intercept the moisture 

 brought by the prevailing west winds from the Pacific Ocean ; rains 

 will be copious on tlieir summits, and in Chili on the their western 

 declivities, but mme will fall on the plains to the eastward, except 

 occasionally when the winds blow from the Atlantic." 



And he adds, — " The views on the sal)jeut of climate we have been 

 unfolding will enable us to throw some light on an interesting point, 

 the distribution of ft) ests." 



Thtre is a[>pended a small map of America, in which by long 

 hatched lines are shown the positious of the chains of mountains ; 

 white spaces rL-presout land* o.i wliich little or no wooi grows ; 

 shading represent the regiou-s of fjrjsts, dease forests bjing repre- 

 sented by double sl»a ling, au I thiuuar o les by open Hues; while 

 arrows i.idic ate the direction of prevailing winds. And in explanation 

 it is stated, — " In speaking of the rejim of forests, we neither restrict 

 tie term to those districts where the n itural wojds present au un- 

 brukjn continuity, nor extend it to every place where a few trees 

 grow in open plains. It is not easy to give a de.l;iiti<m that will be 

 always appropriate ; but in using the ex[>ression we vvisli to be under- 

 stood as applying i: to groan 1 where the natural wools cover more 

 than one-fourth of the surface." An 1 there is given the following 

 statement in regard to the distribution of the forests, — " In North 

 America, to the west of the Rocky mountains, is thus represented a 

 woody region, extending from lat. 35' to about 58°, of unknown 

 breadth, densely wooded from the coast, more thinly wooded towards 

 the mountain range ; to the east of the mountains, an extensive 

 region stretching E.NE. to the ocean, partly a bare desert, partly 

 covered with grass and clothed with trees. On the east coast and 

 more to the south is the Allegany range, with dense forests on the 

 east and the south and thin on the west, the forest region thus 

 indicated being bounded by a curved line passing from the mouth of 

 the St. Lawrence, in lat. 50", through Lake Huron to St. Luis in 

 Mexico ; and an arrow points out the direction of the wind turned 



