E. E. Eoicorfh—A Great Pod-Glacial Flood. 13 



tlirougliout, as is tlie case with the Loess of China, is unknown, 

 and is, prima fade impossible. Lastly, the postulating of a change 

 of level of at least 6000 feet in China, in quite recent geological 

 times, and of a very extensive and wide- spread change in Europe 

 also, is invoking a quite stupendous cause to account for what is 

 much more completely accounted for by a much simpler one. 

 On every ground we may conclude that there is no evidence 

 that the sea has ever overspread the two continents of Asia and 

 Europe since the deposition of the Loess, but, on the contrary, all 

 the evidence points to the Loess having been other than a marine 

 deposit. 



Having discarded salt-water and its partizans, we must now con- 

 sider the theories of those who make the Loess a fresh- water deposit. 

 Some of these argue that it is of lacustrine, and others of fluviatile 

 origin. Both agree that lake and river, however, are merely instru- 

 ments by which the Loess was distributed, and urge that its origin 

 is to be traced to the glacial mud formed by Alpine and other 

 glaciers at the time when the Ice Age predominated. In this view 

 all the partizans of fresh-water are agreed. Lyell, Belt, and Geikie, 

 differing in other respects, are at one in this. Yet we may seriously 

 ask on what possible ground, save a purely hypothetical one, this 

 view has been maintained. The Alpine glaciers are no doubt much 

 smaller now than they were in the great Ice Age, but otherwise they 

 are doing precisely the same work, grinding the same rocks, and 

 pouring out the same debris of denudation. Their great outlets, the 

 Ehine and the Ehone in the North, and the Po in the South, are 

 carrying seawards the same kind of matter in suspension that they 

 formerly did. At all events, if this be not so, the burden of proof 

 of showing the contrary is assuredly upon those who deny the fact. 

 If this be so, how comes it that nothing like the Loess is being manu- 

 factured now by the Alpine glaciers ; that the sediment contained in 

 the Ehine and the Ehone, except such part of *t as is washed from 

 the banks along which they flow, is other than Loess ? How is it 

 that at Bonn the Ehine water contains no appreciable carbonate of 

 lime as Bischoflf has shown ? How is it that wherever we can trace 

 deposits directly due to glacial action — ex. gr. those being formed 

 at the feet of the Greenland glaciers and the great beds of materials 

 which the glacial age has left in varioiis parts of North Britain and 

 North America consisting of clays of various kinds, — how is it, we 

 say, that nothing in the shape of Loess is to be traced here, but that 

 these deposits in texture, composition, and other characters are quite 

 different from Loess, properly so called? Assuredly there can be but 

 one conclusion, if we reason inductively, namely, that the Loess is 

 not a Glacial mud at all, but had a very different origin. Let us 

 now turn to the several theories of its distribution. First we will 

 consider the lacustrine theory. This view was inspired by the 

 limited area of the Ehine Valley. It was suggested, in fact, that 

 the Loess which mantles that valley and those of its tributaries was 

 deposited by a great lake, banked up by abarrier in the narrow gorge 

 between Bingen and Coblentz. When, however, it was shown that 



