Produced by Steve Harris, Charles Franks
and the Online Distributed Proofreading Team.
"Not all the winds, and storms, and earthquakes, and seas, and seasonsof the world, have done so much to revolutionize the earth as MAN, thepower of an endless life, has done since the day he came forth upon it,and received dominion over it."—H. Bushnell, Sermon on the Power of anEndless Life.
1874.
The object of the present volume is: to indicate the character and,approximately, the extent of the changes produced by human action in thephysical conditions of the globe we inhabit; to point out the dangers ofimprudence and the necessity of caution in all operations which, on alarge scale, interfere with the spontaneous arrangements of the organicor the inorganic world; to suggest the possibility and the importance ofthe restoration of disturbed harmonies and the material improvement ofwaste and exhausted regions; and, incidentally, to illustrate thedoctrine that man is, in both kind and degree, a power of a higher orderthan any of the other forms of animated life, which, like him, arenourished at the table of bounteous nature.
In the rudest stages of life, man depends upon spontaneous animal andvegetable growth for food and clothing, and his consumption of suchproducts consequently diminishes the numerical abundance of the specieswhich serve his uses. At more advanced periods, he protects andpropagates certain esculent vegetables and certain fowls and quadrupeds,and, at the same time, wars upon rival organisms which prey upon theseobjects of his care or obstruct the increase of their numbers. Hence theaction of man upon the organic world tends to derange its originalbalances, and while it reduces the numbers of some species, or evenextirpates them altogether, it multiplies other forms of animal andvegetable life.
The extension of agricultural and pastoral industry involves anenlargement of the sphere of man's domain, by encroachment upon theforests which once covered the greater part of the earth's surfaceotherwise adapted to his occupation. The felling of the woods has beenattended with momentous consequences to the drainage of the soil, to theexternal configuration of its surface, and probably, also, to localclimate; and the importance of human life as a transforming power is,perhaps, more clearly demonstrable in the influence man has thus exertedupon superficial geography than in any other result of his materialeffort.
Lands won from the woods must be both drained and irrigated; river-banksand maritime coasts must be secured by means of artificial bulwarksagainst inundation by inland and by ocean floods; and the needs ofcommerce require the improvement of natural and the construction ofartificial channels of navigation. Thus man is compelled to extend overthe unstable waters the empire he had already founded upon the solidland.
The upheaval of the bed of seas and the movements of water and of windexpose vast deposits of sand, which occupy space required for theconvenience of man, and often, by the drifting of their particles,overwhelm the fields of human industry with invasions as disastrous asthe incursions of the ocean. On the other hand, on many coasts,sand-hills both protect the shores from erosion by the waves andcurrents, and shelter valuable grounds from blasting sea-winds. Man,therefore, must sometimes resist,