CHAPTER VI. 
GREAT PROJECTS OF PHYSICAL CHANGE ACCOMPLISHED OR PRO- 
POSED BY MAN. 
Cutting of Isthmuses—Canal of Suez—Maritime Canals in Greece —Canals to 
Dead Sea—Canals to Libyan Desert—Maritime Canals in Europe—Cape 
Cod Canal—Changes in Caspian—Diversion of the Nile—Diversion of the 
Rhine—improvements in North American Hydrography—Soil below 
Rock—Covering Rock with Harth—Desert Valleys—Effects of Mining— 
Duponchel’s Plans of Improvement—Action of Man on the Weather— 
Resistance to Great Natural Forces—Incidental Effects of Human Action 
—Nothing small in Nature. 
Ty a former chapter I spoke of the influence of human ac- 
tion on the surface of the globe as immensely superior in 
degree to that exerted by brute animals, if not essentially dif- 
ferent from it in kind. The eminent Italian geologist, Stop- 
pani, goes further than I had ventured to do, and treats the 
action of man as a new physical element altogether svz generis. 
According to him, the existence of man constitutes a geological 
period which he designates as the anthropozoic era. “'The 
creation of man,” says he, “was the introduction of a new ele- 
ment into nature, of a force wholly unknown to earlier 
periods.” “It is a new telluric force which in power and uni- 
versality may be compared to the greater forces of the earth.” * 
It has already been abundantly shown that, though the unde- 
signed and unforeseen results of man’s action on the geogra- 
phical conditions of the earth have perhaps been hitherto 
greater and more revolutionary than the effects specially aimed 
at by him, yet there is scarcely any assignable limit to his 
* Corso di Geologia, Milano, 1873, vol. ii., cap. xxxi., $ 1327. 
39 
