Peppebcorne. — On the Influence of Forests on Climate and Rainfall. 27 



in former times they were elotlied with dense forests, and their oldest 

 inhabitants remembered when the rains were abundant, and the hills and 

 all uncultivated places were shaded by extensive groves. The removal of 

 the trees was certainly the cause of the evil. The opening of the soil to the 

 vertical sun rapidly dries up the moisture, and prevents the rain from 

 sinking to the roots of plants. The rainy seasons in these climates are not 

 continuous cloudy days, but successions of sudden showers, with the sun 

 shining hot in the intervals. Without shade upon the surface the water is 

 rapidly exhaled, and springs and streams diminish." 



The opinion of so eminent a botanist as Dr. Hooker must be conclusive 

 on this subject ; and in the Keport of the United States' Commissioner of 

 Agriculture for 1871, there occurs the following passage: — "In Upper 

 Egypt, the rains which, eighty years ago, were abundant, have ceased since 

 the Arabs cut down the trees along the valley of the Nile towards Lybia and 

 Arabia. A contrary effect has been produced in Lower Egypt from the 

 extensive planting of trees by the Pasha. In Alexandria and Cairo, where 

 rain was formerly a great rarity, it has, suace that period, become more 

 frequent. ' ' 



Again, speaking of the State of New York, and of the lofty mountains 

 amongst which its principal rivers take their rise. Professor Marsh says : — 

 " Nature threw up those mountains, and clothed them with lofty woods, in 

 order that they might serve as a reservoir to supply with perennial waters 

 the thousand rivers and rills that are fed by the rains and the snows of the 

 ' Adirondacks,' and as a screen for the fertile plains of the central counties, 

 against the chilling blasts of the north wind, which meet no other barrier in 

 their sweep from the Arctic Pole. The climate of Northern New York even 

 now presents greater extremes of temperature than that of Southern France. 

 During what is called the 'heated term,' the weather is almost tropical, 

 and the deaths from sunstroke, even in the city of New York, which 

 lies at the most southerly point of the State, may be reckoned by scores, 

 while the winters have become of late years quite Siberian in their 

 severity." 



With regard to the felling of the Adirondack woods, and the effects 

 thereof, Professor Marsh warns his countrymen that then- destruction will 

 render a wide-spread desolation inevitable, and he dwells on this point, 

 because we are apt to think that America possesses exhaustless forests : — 

 " Already (he says) the rivers which rise in that region flow with diminished 

 currents in dry seasons, and with augmented volumes of water after heavy 

 rains. They bring down larger quantities of sediment ; and the increasing 

 obstructions to the navigation of the Hudson, which are extending them- 

 selves down the channel in proportion as the fields are encroaching on the 



