106 ~— Burton: Lincolnshire Coast Boulders. 
and outflows; all of which deposit in the aggregate vast tracts 
of mud and sand, covering up the shallow sea-bed and extending 
in places, as at Saltfleet, a mile or more out from the land; and 
in all this I fail to see any evidence of a ‘ powerful tidal scour’ _ 
along the coast, which, if it existed, and was capable of trans- 
‘porting boulders along the shore, would surely be able to sweep | 
away the soft deposits of mud and sand which encumber it. 
It is not, however, with the present day only that'we have | 
to deal; we must go back to the time when the powerful stream 
of the Trent swept through the Lincoln Gap, where the Witham 
now flows, spreading the drainage of the Midlands over the 
shallow sea-bed, and irresistibly opposing any tidal current that 
could, on such a flat coast as that of ‘Lincolnshire, be brought 
against it; and if it could be proved that this river was diverted 
from its course through the Gap before the Glacial period, when 
testified when the land to the east of Lincoln resembled more an 
inland lake, or the bay of a sea, than a river’s flood. : 
Let us turn now to the two letters I have referred to. of 
Mr. Atkinson writes (18th July 1898) :— y 
‘Mr. Harker’s theory that these erratics may have been _ 
brought from the Holderness coast by the tidal scour is scarcely 
tenable. No doubt the action of the tidal drift is a very 
important one, but he has overlooked the existence of the wide 
and deep embouchure of the Humber. The Humber currents © 
are tranverse to the general direction of the littoral drift, and 
probably interrupt its continuity for ‘some distance from the — 
shore.’ 
r. Wheeler, who, it is well known, has pane tidal action — 
aac study, deals more fully with the subject, and writes 
s follows (8th July 1898) :— 
‘I have recently, in pursuit of my investigations into the 
matter of littoral drift, inspected the Yorkshire and Lincolnshire 
coast from Hornsea to Sutton. I was at Sutton soon after the 
great storm in March, which had in several places between 
Mablethorpe and Sutton bared the clay. : I found several | 
patches and small beds of stones. The conclusion I arrived 
‘Naturalist, 
