19 
ultimately scooped out the chalk-valleys, and the Sarsens, dropping 
down ag the valleys deepened, finally found their present resting 
places. 
It had often been conjectured that the blocks were transported 
from great distances by glacial agency ; but there was no sufficient 
grounds for such an opinion, inasmuch as the stones were all of one 
local formation; whereas far travelled ice-borne boulders would most 
likely include rocks of very diverse kinds. It was quite probable, 
however, that ground-ice might have been an agent in transporting 
some of the larger masses for considerable distances along the valleys. 
Indeed, the abrupt escarpments on some of the hill sides, in the course 
of the chalk-valleys, so different in aspect from the ordinary rounded 
outlines which characterise chalk districts, pointed to some grinding 
action in their production, and such as might have arisen from masses 
of ice formed at the bottom of the streams, and which rising to the 
surface laden with stones and gravel, were swept onwards with im- 
‘mense force by the flood-waters, scarping the valley projections in 
their progress. A paper by Engelhardt, of which a translation 
appeared in the “Smithsonian Report” for 1866, pointed out the conse- 
quences of these ice-drifts in choking the rivers, and during a rapid 
thaw, flooding the Rhenish and Danubian provinces, 
‘This grooving process had left unmistakable evidence of its 
q handiwork in the drift lying along the sides of the Kennet-vale, at a 
height of, in some places, 60 feet above the present valley level, 
_ showing that the stream had once occupied that height. Thus the 
‘upper and lower beds were of very different ages. And although 
some of the Sarsens were unworn and untravelled, others showed 
signs of rough usage from swift-currents of long duration, as they were 
found in places, as on Inkpen Common, drifted in amongst hetero- 
geneous materials, derived from every formation in the London Basin. 
At an indefinitely less distant period the present diminished stream 
_ commenced flowing through the valley. All these several conditions 
were not accomplished without much and diversified handling on the 
_ part of the many handmaids employed by Nature. The land rose 
_ slowly or by starts, the terraces, probably, marking the changes of 
o> level ; and when the more powerful of the denuding agents had ceased 
_ their operations, the lower valleys had begun to retain the gravel 
obtained from the older gravel beds on the higher ground, and of the 
—- 
7 
= tee ehh OS 
