140
THE QUESTION OF WORKABLE
throwing off the Westphalian coalfield ; but that on the contrary the
multiple axis of the Devonian district of Sauerland, to the north of
which this coalfield lies, is really a feebler continuation of the
Ardennes axis, which rises to its highest elevation in the Hohe Veen,
from which it has been severed by a quondam arm of the sea now
occupied by the broad valley of the Rhine about Cologne as drawn
on Mr. Harrison's map. One is thus led to reject the conjecture
upon which the diagram in question is based, so far as the existence
of a synclinal coal measure trough under North Essex is concerned ;
and the whole diagram is seen to be still further misleading, when
one recognises the fact, that, in what professes to be a continuous
section, the line of country represented by that portion of the section
which extends from Dover to London is about at right angles to the
general trend of the remaining portion of the section. A further
difficulty arises if we attempt to reconcile Mr. Harrison's map with
his sectional diagram, for in the former he has postulated an axis
of elevation running north from London, the evidence of the borings
quoted showing a general dip of the strata to south, as shown in the
diagram.
GENERAL CONCLUSION.
The view which I am inclined to take from the foregoing con-
siderations is that the existence of the Lower Carboniferous strata
beneath Harwich points to a possible general dip of the strata from
the Herts and East Anglian Palaeozoic axis to the south-east, the
dip indicated in the line of borings partaking of this, but not
representing the true dip of the Palaeozoic strata ; and that the Dover
coal measures may be continued under the Nore and might be
reached in South-East Essex. Of their occurrence in North Essex
I see no probability. When the actual dip of the Coal Measures at
Dover is proved by sinking shafts into them new light will be thrown
upon this ; meanwhile, no more useful experiment perhaps could be
tried than (as is, I believe, contemplated) the execution of a second
boring into the Lower Carboniferous strata a little way from Harwich,
so as to ascertain the dip of those strata in that region.
Note.
Writing on August 1st, Dr. Irving adds : "A paper by Messrs.
W, Whitaker, F.R.S., and A. J. Jukes-Browne, was read at the
meeting of the Geological Society on June 20th, and has since been
published ("Jour. Geo. Soc." vol. 1., pp. 448-514). It contains a list