114 OUTLINES OF FORESTRY. 



longer protected by the forests is thus described 

 by Sir Charles Lyell, in his " Principles of Ge- 

 ology, or the Modern Changes of the Earth and 

 its Inhabitants," * on page 338, vol. i. : 



" When travelling in Georgia and Alabama in 1846, I saw 

 in both these States the commencement of hundreds of val- 

 leys in places where the native forests had recently been re* 

 moved. One of these newly-formed gulleys or ravines is 

 represented in the annexed wood-cut, from a drawing which 

 I made on the spot. It occurs three miles and a half due west 

 of Milledgeville, the capital of Georgia, and is situated on the 

 farm of Pomona, on the direct road to Macon. 



" In 1826, before the land was cleared, it had no existence ; 

 when the trees of the forest were cut down, cracks three feet 

 deep were caused by the sun's heat in the clay ; and during 

 the rains, a sudden rush of water through the principal crack 

 deepened it at its lower extremity, from whence the excavating 

 power worked backward, till, in the course of twenty years, a 

 chasm measuring no less than fifty-five feet in depth, three 

 hundred yards in length, and varying in width from twenty to 

 one hundred and eighty feet, was the result. The high road 

 had been several times turned to avoid this cavity, the enlarge- 

 ment of which is still proceeding, and the old line of road may 

 be seen to have held its course directly over what is now the 

 widest part of the ravine. In the perpendicular walls of this 



*" Principles of Geology," by Sir Charles Lyell, F.R.S., 

 M.A. London: John Murray, Albemarle Street, 1872. Pp. 

 650. 



