Ancient Drainage of JVorth America, SfC. 15 



adaptation of causes, that continents are drained, so many great 

 purposes answered, and the whole volume of atmospheric waters 

 finally returned to the ocean, whence it is again drawn up into 

 the atmosphere, to be again and again distributed upon the earth, 

 for its fertilization. 



In seeking the lowest levels, the great rivers frequently em- 

 brace in their course, depressions or basins that do not conform 

 to their mean breadth. These larger bodies of water, when 

 spreading themselves far beyond such mean breadth, are usually 

 called lakes. Others, from their extent, are well entitled to be 

 called " inland seas." The origin of such lakes is various, and 

 will not be considei'ed at this time. Of the lake of Geneva, how- 

 ever, which forms part of the course of the Rhone, it may be, 

 remarked, that there are geological considerations belonging to 

 it, which suggest, that in ancient periods, the vast basin in which 

 its waters now rest, did not exist; and that it is not improbable an 

 inclined solid plane existed between the Alps and the Jura. The 

 small lakes of St. Francois, St. Louis, &c. on the St. Lawrence, are 

 instances of this widening of rivers into basins. Lake Superior, and 

 the great body of water constituting lake Michigan and lake 

 Huron, belong to the class that might be called inland seas. 



In that very useful and popular volume, " Darby's view of 

 the United States," the author has had to struggle, — and not 

 very successfully occasionally — through some interesting branches 

 of a subject, he has, upon the whole, treated in an able manner. 

 The language he holds, at page 65, of the mountains of the 

 Appala<;hian system, being specifically and generally distinct 

 from the hills, would, if not quite satisfactory, have been less 

 obscure, had he, before venturing on a work of such importance, 

 paid proper attention to a science, the value of which does not 

 apparently rank very high in his estimation. Considering that 

 his work was published in 1828, this is very surprising. In 

 the preface we find the following passage. " Geology, as it 

 stands in our books, being a science, (if it deserves the name of 

 a science,) of conjecture, I have rejected, as far as practicable, 

 terms that teach nothing definite." What books are here referred 

 to, Mr. Darby has not stated; but this may be most truly said, that 

 books were extant before 1828, the study of which would have 

 enabled him to define, in a very precise manner, the particulars 

 upon which every branch of physical geography depends, and 



