170 J. R. Dakyns — Sediment Theory of Drift. 



intercalations of laminated beds, the further we go from the central 

 fells. The general mass should change in character horizontally ; 

 but should not offer any such fixed and neat sequence as Lower 

 Till, Middle Sands, Upper Till. Again, Mr. Goodchild would 

 explain the Middle Sands and Eskers in the same way, as results 

 of one and the same cause. Whence then their difference ? Eskers 

 are specially distinguished by their 1 arched bedding, their included 

 hollows, and the " ghosts of scratches " on the pebbles. If due to 

 the same cause, why are they so markedly different from the flat 

 spread of the Middle Sands with its false bedding of the ordinary 

 character? Their difference of form bespeaks a difference of forma- 

 tion. Nor do I see that they offer any insurmountable difficulty. I 

 used once to be much puzzled by them ; but the idea of conflicting 

 currents, which I got from Mr. Fox Strangways, seems to clear up 

 the mystery of the land-locked hollows, etc. Does any one suppose 

 that, were the North Sea bottom laid bare, we should not find 

 regular Esker mounds in the sand-banks, whose existence causes 

 such unpleasant sensations to the Norwegian voyager? 



The very general prevalence of Esker and other sands and gravels 

 up to the height of 700 or 800 feet above the sea-level is itself ah 

 argument in favour of a submergence of the land to that amount : 

 and this idea is immensely confirmed by the proofs in Norway of a 

 like amount of recent submergence, afforded by horizontal terraces 

 of sand, the remains of old deltas and beach-marks along the solid 

 rock over the sea, to say nothing of the shells. Moreover, if I 

 mistake not, the grooves on the top of Bar Fell in Yorkshire are 

 themselves evidence of submergence at least to the extent of 2200 

 feet. The reason is this : the North and West Ridings of Yorkshire 

 were, like other mountain groups, to wit, Norway, Scotland, the 

 Lake Mountains, and Iar-Gonnaught, glaciated radially : that is, the 

 ice flowed outward from the central fells in all directions, much in 

 the same way as the rivers do now : the snow and ice drainage was 

 broadly analogous to the water drainage. 



The great dales, Wensleydale, Wharfedale, Nitherdale, Ribbles- 

 dale, Dent, contain no foreigners in the Drift : the Drift material is, 

 as far as I know, entirely composed of rocks from the basins of the 

 separate dales. There is thus no evidence of any far-derived ice, 

 whether an ice-cap moving from the pole or an ice-sheet from a distant 

 mountain group. All the evidence is in favour of home-made ice. 



The general centre whence the ice moved outward may roughly 

 be placed about Bar Fell. Now at the radiant centre, where the 

 motion is merely nascent, there can be no grooving, both because 

 the motion is practically nil and because the ice has had no time nor 

 space wherein to gather its grooving tools. As well expect to find 

 denudation of rocks going on in the peaty marsh, whence issue the 

 rivers Wharfe and Kibble, where the flow of the water is so feeble 

 that it is hard to say which way it will go, as to find scratches under 

 the ice at its starting-point. Yet Bar Fell is grooved on its summit. 



1 See my section of gravel-pits near York, in the Quarterly Journal of the Geol. 

 Society for Novemher, 1872. 



