Sir H. H. Howorth — Surface Geology of N. Europe. 203 



be able to move up and down slightly imdulating districts, and 

 sometimes to creep uphill to a moderate extent, it would be an 

 entirely new and surprising fact that water could do so, unless 

 contained in a pipe and forced up by pressure behind. This is an 

 initial difficulty of the first moment, and is in fact absolutely 

 conclusive. Water, except in a pipe, cannot move contrary to 

 gravity, cannot travel up and down hill, or mount a slope; and 

 it does not matter whether the water is in a channel open to the 

 sky, or in a channel covered with an arched tunnel of ice. It 

 is therefore impossible on this ground alone that the asar could 

 bave been deposited by rivers of any kind, unless the contour of 

 the country has entirely and radically changed since they were 

 laid down. 



This is by no means the only objection to the fluviatile 

 theory of the asar. Their shape, when viewed in section, is quite 

 opposed to a fluviatile origin. Rivers which run vei-y slowly and 

 carry much mud, instead of depositing that mud entirely in deltas, 

 sometimes, no doubt, raise their own beds, like the lower Ehine 

 and some rivers of Eastern England do, and in this way make 

 themselves solid aqueducts along which they flow. These solid 

 aqueducts, however, have not the shape or contour of asar, with 

 their often steep and sharply inclined sides. This contrast in 

 contour is even more marked in the heaps of debris which form 

 the beds of subglacial streams. Nor can I see how rivers of any 

 kind could raise their beds to the portentous height of the asar 

 and yet be so narrow. Elvers, again, must have banks, and if of 

 fluviatile origin the asar should form channels running along their 

 crests. The solid aqueducts we have experience of elsewhere are 

 none of them very high, but are always breached and broken 

 through alter a time, when the river escapes and forms itself 

 another channel, leaving the old bed meandering like a gigantic 

 snake in the valley bottom. We cannot conceive such solid 

 aqueducts remaining intact until they have been raised to a height 

 of 300 or 400 feet. 



Another difficulty presents itself when we compare the contents 

 of the asar with those of such river-channels as we can examine. 

 Rivers which elevate their beds by gradual deposits are necessarily 

 sluggish and slow-flowing rivers. When rapid, rivers become 

 scouring agencies and not depositing ones. How is it possible to 

 conceive of a sluggish river depositing these enormous masses of 

 cannon-shot gravel — not of laying down a few yards of suoh 

 gravel when there is an occasional rush in the stream, but a rampart 

 a hundred miles in length and fifty yards high? The position is 

 incredible. The Nile, the Rhine, the Indus, the Amazon, all these 

 deposit beds, but they are beds of finely sifted mud. Again, in 

 depositing stones, rapid rivers sift them according to their specific 

 gravity, and do not mingle them higgledy-piggledy as they are 

 mingled here. If it was a river that deposited these mountains 

 of boulders, it must have been a very violent torrential river, and 

 its force quite portentous along its whole course. If so, how is 



