HAS THE EXTEXT OF LAND SURFACE BEEN INCREASING? 211 



them has become elevated, plicated, metamorphosed and embossed with 

 volcanoes."* 



It is not, however, by any means possible to admit that the statements 

 made in the last paragraph quoted are in accordance with the facts. The 

 areas now occupied by the continents have not " from the beginning " been 

 the '• nearly stable areas." On the contrary it is precisely these areas which 

 have been regions of disturbance, and in some parts of enormous disturb- 

 ance ; and it is not alone their edges which have been " elevated, plicated 

 and embossed with volcanoes." t This, however, is not a subject coming up 

 for discussion at the present time ; at least not to any farther extent than is 

 necessary to throw light on the question whether the quantity of land on 

 the globe has been on the whole increasing. Nor can this question be con- 

 sidered to have been by any means decided by what was published at this 

 early stage of the inquiry. Dana does indeed state that the outlines of the 

 North American continent had been marked out at an earh* period in geolo- 

 gical history, or, to quote his exact words : " The continents and oceans had 

 their general outline or form defined in earliest time. This has been proved 

 with regard to North America t from the position and distribution of the first 

 beds of the Lower Silurian, those of the Potsdam epoch. The facts indicate 

 that the continent of North America had its surface near tide-level, part 

 above and part below it, and this will probably be proved to be the condition 

 in Primordial time of the other continents also. And if the outlines of the 

 continents were marked out, it follows that the outlines of the oceans were 

 not less so."§ 



» JLinual of Geology, Pliiladelpliia, 1863, pp. 732, 733. 



+ In support of the statement here made, reference may be made to the well-known facts in regard to the 

 geology of the Cordilleras of North America. Here, over a belt a thousand miles in width, during the Tertiary 

 period — not to speak of what hajipened before that — volcanic action took place on a most gigantic scale. By this 

 action mountain ranges were built up ; and not only by this, but by actual uplift, the entire Rocky Mountain 

 Range in the interior of the continent having received its form and final finish in Pliocene times. Similarly it 

 may be said of Asia that its elevated portion is cential in reference to its development. The laud of that conti- 

 nent has grown around a central nucleus; and not been formed by plication and embossing of its edge with 

 volcanoes. 



J This statement seems to have been based on the investigations of Messrs. Foster and Whitney, as published 

 by them in their Lake Superior Report, and in an article read before the American Association for the Advance- 

 ment of Science, at the Cincinnati Meeting, in 1851, and entitled, "On the different systems of elevation which 

 have given configuration to North America, with an attempt to identify them with those of Europe." So little 

 was known at that time, however, of the geological structure of the great complex of the Cordilleras, that the state- 

 ment quoted above could not liave been said to be "proved with regard to North America," even if it were con- 

 sidered to be so for the noitheasteni and eastern portions of the continent. 



§ Mauual of Geology. First Edition, 1863, p. 732. 



