Vili PREFACE TO THE PRESENT EDITION. 
Since the publication of the original edition, Mr. Elisée 
Reclus, in the second volume of his admirable work, La Terre 
(Paris, 1868), lately made accessible to English-reading stu- 
dents, has treated, in a general way, the subject I have under- 
taken to discuss. He has, however, occupied himself with the 
conservative and restorative, rather than with the destructive, 
effects of human industry, and he has drawn an attractive and 
encouraging picture of the ameliorating influences of the ac- 
tion of man, and of the compensations by which he, consciously 
or unconsciously, makes amends for the deterioration which he 
has produced in the medium he inhabits. The labors of 
Mr. Reclus, therefore, though aiming at a much higher and 
wider scope than I have had in view, are, in this particular 
point, a complement to my own. I earnestly recommend the 
work of this able writer to the attention of my readers. 
GEORGE P. MARSH. 
Rome, May 1, 1873. 
