THE EARTH 



AS MODIFIED BY HUMAN ACTION. 



CHAPTER I. 



INTRODUCTOEY. 



Natural Advantage? of the Territory of the Roman Empire. — Physical Decay 

 of that Territory. — Causes of the Decay. — Reaction of Man on Nature. — 

 Observation of Nature. — Uncertainty of Our Historical Knowledge of 

 Ancient Climates. — Uncertainty of Modern Meteorology. — Stability of 

 Nature. — Formation of Bogs. — Natural Conditions Favorable to Geo- 

 graphical Change. — Destructiveness of Man. — Human and Brute Action 

 Compared. — Limits of Human Power. — Importance of Physical Conser- 

 vation and Restoration. — Uncertainty as to Effects of Human Action. 



Natural AdmaMages of the Territory of the Roman Empire. 



The Roman Empire, at the period of its greatest expansion, 

 comprised the regions of the earth most distinguished bj a happy 

 combination of physical conditions. The provinces bordering on 

 the principal and the secondary basins of the Mediterranean en- 

 joyed, in healthf ulness and equabihty of climate, in fertihty of 

 soil, in variety of vegetable and mineral products, and in natural 

 facilities for the transportation and distribution of exchangeable 

 commodities, advantages which have not been possessed in an 

 equal degree by any territory of like extent in the Old World or 

 the New. The abundance of the land and of the waters adequately 

 suppHed every material want, ministered hberally to every sensu- 

 ous enjoyment. Grold and silver, indeed, were not found in the 

 profusion which has proved so baneful to the industry of lands 

 richer in veins of the precious metals ; but mines and river beda 

 yielded them in the spare measure most favorable to stability of 

 value in the medium of exchange, and, consequently, to the regu- 

 larity of commercial transactions. The ornaments of the barbaric 



