248 THE POPULAR SCIENCE MONTHLY. 



severed the apron -string, and ceased to be tlieologic, but it still to 

 its credit remained cosmologic. It traced the earth from chaos 

 up to a stage when islands and continents rose out of a primeval 

 ocean, the waters of which were boiling ; saw it peopled with 

 strange and various forms of life, and watched it run its course, 

 rejoicing in the sun, "cheerful, fresh, and full of joyance glad," 

 then pictured it overtaken with disasters, shaken with earth- 

 quakes, overwhelmed by floods, and agonizing in the labors of 

 a new birth. Calm followed after storm, and life rejoiced afresh 

 in a remade world to be again destroyed. Thus, through alterna- 

 tions of peace and strife, the earth moved on its changeful way, 

 to the crowning creation of man, who was himself a living wit- 

 ness of the last great catastrophe of all, the Noachian deluge. 

 Its waters covered the whole earth, to the tops of the highest 

 mountains under heaven, and on their retreat they left behind, 

 as a standing witness to their extension, great sheets of sediment, 

 supposed to be spread out over the entire surface of the globe, 

 and appropriately named the " diluvium." The diluvium may 

 be seen in most parts of the British Isles, except in the south of 

 England ; it consists of clays and sands, containing vast numbers 

 of curiously scratched stones. 



As the powers of geology matured it became increasingly able 

 to dispense with catastrophes. The very diluvium itself was 

 shown to be local in its distribution, and glacial in its origin ; 

 masses of moving ice, like that which buries the greater part of 

 Greenland out of sight, covered a large part of the temperate 

 regions, and this it was that produced the curious scratched 

 stones ; and the deposits containing them, which are consequently 

 no longer called " diluvial " but " glacial." More important yet, 

 land could be shown to be still actually rising from the sea, and 

 mountains growing into the air, but so slowly that the fact was 

 not established without much dispute, which is hardly yet over. 

 Valleys could be shown to result, not from any bodily fracturing 

 of the land, but from the slow wearing action of the rivers which 

 flow through them, and the waves of the sea were shown to be 

 capable of cutting down cliffs and of reducing the land to a plain. 



From these facts the discordance in the succession of strati- 

 fied rocks found an easy solution. Recurring to the instance of 

 the carboniferous rocks and their relations to the trias, we no 

 longer need suppose that the stupendous force which folded the 

 carboniferous rocks and raised them into the air acted suddenly 

 or even very rapidly ; judging from the rate at which mountains 

 rise now, their upheaval may have jjroceeded slowly ; a few feet 

 in a century would suffice. If we allow but one foot in a century, 

 it would only require two million years to produce a mountain 

 range twenty thousand feet in height. The movement might 



