IN THE NEIGHBOURHOOD OF ALNWICK. 357 
and the irregular outline of the sea bottom would give a local 
character to each separate accumulation, and hence, though con- 
temporaneously formed, and consisting of similar materials, 
these accumulations, do not exhibit the same sequence. 
Concurrently with these movements, icebergs detached from 
glaciers protruding into the sea, in more northern latitudes, and 
laden with the rocks and debris of these northern lands, appear 
to have floated into the Northumberland sea, and, in their course 
occasionally dropt their rocky burdens ; at other times they have 
grounded, and by their gravity and force polished the rocks over 
which they moved, the particles of hard minerals, embedded in 
the ice, acting as gravers and striating and grooving the surface ; 
nor does it seem improbable that these bergs have sometimes struck 
against the accumulations of gravel, sand, and clay, and forced 
the different beds over each other, and given to them the com- 
plicated and irregular arrangement exhibited in the sections at 
Holy Island, and in the neighbourhood of Alnwick. But as the 
blocks in the boulder clay are chiefly derived from rocks, in situ, 
in the neighbourhood, I attribute most of the phenomena, not re- 
ferable to water-agency, to the action of coast ice, which would be 
formed around the Island shores, and in which rocks from the cliffs 
and beach would be enclosed ; portions of this ice may have, from 
time to time, been detached and floated away to short distances, 
carrying with them and depositing as they melted, local blocks and 
debris, and when driven violently on submarine hills, producing 
similar effects in polishing and scratching surfaces, as result from 
the stranding of bergs. 
Independently of the interest surrounding even a stray frag- 
ment of the physical history of the earth, the highest gratification 
must be felt by every intelligent mind on observing the beneficial 
influence on the present era, arising from the repeated changes 
which have occurred during past geological epocha. Progression 
may be seen marked on the physical as well as on the moral 
history of the world. The hard intractable primary rocks could 
yield little, in their original state, for the support of animal life ; 
these have been broken up and reformed by the manifold revolu- 
tions of the past ; the new products have again and again been 
