PHYSICAL CONSERVATION AND RESTORATION. 47 



tion, will continue to sink into yet deeper desolation, and in the 

 meantime tlie American continent, Southern Africa, Australia, 

 New Zealand, and the smaller oceanic islands, will be almost the 

 only theatres where man is engaged, on a great scale, in trans- 

 forming the face of nature. 



ImportanGe of PhysicaZ Conservation omd Restoration. 



Compai'atively short as is the period through which the coloni- 

 zation of foreign lands by Em*opean emigrants extends, great and, 

 it is to be feared, sometimes irreparable injury has ah'eady been 

 done in the various processes by which man seeks to subjugate 

 the virgin earth ; and many provinces, first trodden by the Jwmo t 

 sapiens Eurojpce within the last two centuries, begin to show 

 signs of that melancholy dilapidation which is now driving so 

 many of the peasantry of Europe from their native hearths. It 

 is evidently a matter of great moment, not only to the population 

 of the states where these symptoms are manifesting themselves, 

 but to the general interests of humanity, that this decay should 

 be arrested, and that the future operations of rural husbandry and 

 of forest industry, in districts yet remaining substantially in their 

 native condition, should be so conducted as to prevent the wide- 

 spread mischiefs which have been elsewhere produced by thought- 

 less or wanton destruction of the natural safeguards of the soil. 

 This can be done only by the diffusion of knowledge on this sub- 

 ject among the classes that, in earher days, subdued and tilled 

 ground in which they had no vested rights, but who, in our time, 

 own their woods, their pastures, and their ploughlands as a per- 

 petual possession for them and theirs, and have, therefore, a 

 strong interest in the protection of their domain against deteriora- 

 tion. 



Physical Restoration. 



Many circumstances conspire to invest with great present in- 

 terest the questions : how far man can permanently modify and 

 ameliorate those physical conditions of terrestrial surface and 

 climate on which his material welfare depends ; how far he can 

 compensate, arrest, or retard the deterioration which many of his 

 agricultural and industrial processes tend to produce ; and how 

 far he can restore fertihty and salubrity to soils which his folHes 



