822

THE COLLIERY GUARDIAN.

October 22, 1915.

of Dover, some little distance from the east coast of Kent, and
forming the eastern boundary. Mr. Bolton had not dis-
cussed that matter; he simply stated that he had not found
any evidence of it. He did not even mention the very weighty
considerations on which that conclusion was based. "With
regard to the question of continuity of the French coal fields,
he (Dr. Arber) had always been at a loss to understand why
anyone should wish to show that the rich and productive field
of Kent was the same thing as the miserable scrap of lower
coal measures situated in the Boulonnais, on the Saddle of
Ferques, which was only five miles in length, with a total
thickness of the rocks of under l,OOOft. According to all
French observers—and there were many—the Pas-de-Calais
coal field ended at least 24 miles from the French coast,
because it was nipped out by folds. He thought the evidence
was absolute that the coal measures did not extend beyond
that region.

He passed to what he took to be Mr. Bolton’s main con-
clusion with regard to the stratigraphy of the field, that
the lowest 700 ft. of the measures were marked off litho-
logically and palaeontologically from the beds above ; accord-
ing to him they consisted of argillaceous sediments in which
sandstones were rare, and they contained a fauna in which
he particularly emphasised four species, Lingula mytiloides,
Orbiculoidea nitida, Productus scrabiculus and Productus
longispinus. He said that those occurred in the Vobster
series of Somerset, and on the same horizon in the Bristol
field. From that he concluded that these 700 ft. of the lower
Kent measures belonged to the same horizon as the Vobster
beds in Somerset and the Ashton series in Bristol. The rest
of the measures, he declared, were essentially arenaceous and,
so far as lithology was cencerned, they were identical with
the Pennant grit of the Somersetshire field. In that he
was repeating the old conclusion which Prof. Boyd Dawkins
was never weary of putting before them. These higher
rocks, Mr. Bolton told them, had a fauna similar to that
of the Pennant and the Farrington series in Somerset, and
therefore they were of the same age. The result was that
Mr. Bolton got out two horizons each a stage higher than
he himself (Dr. Arber) got from the fossil plant evidence.
Translating the horizons into palseobotanical nomenclature,
Mr. Bolton’s upper coal measures corresponded with his
transition coal measures, and Mr. Bolton’s transition coal
measures with his middle coal measues. That he thought,
was the difference between them, and he would like to
criticise, perhaps somewhat severely, the evidence for those
conclusions.

With regard to the lower series of Mr. Bolton, he doubted
very much whether they were lithologically distinct from
the higher beds. He had never been able to see any marked
difference in the sediment of the lower part of the measures
as compared with the upper. He had examined all the
borings very carefully, and to his certain knowledge 25 to
30 per cent, of the rocks in those lower beds were sand-
stone. But has chief criticism rested on the fact that none
of the fossils, especially the four he had named on which
Mr. Bolton relied, were in any degree confined to any
horizon. They not only occurred in every horizon in the coal
measures, but in all horizons of the lower carboniferous
sequence. He was not a specialist upon the fresh water
mollusca, but he met them commonly in borings and knew
something of their vertical distribution. Lingula mytiloides
was one of the commonest. He had found it in the lower
coal measures of Leicestershire, and it also occurred in the
middle coal measures of North Staffordshire. The same
remarks applied to a number of other forms. Mr. Bolton
appeared partially to realise the weakness of his position
in this respect when he quoted Dr. Hind, who was a great
authority upon mollusca, and he attempted to get over the
difficulty by speaking of “ an acceleration or shortening up of
the coal measure period ” in the south-east of England.
That seemed to be the last 'refuge of the stratigraphically
destitute. It was totally opposed to the whole principles
of stratigraphical geology, and the plant evidence alone 'was
sufficient to show that it was not true. Nothing of the sort
took place, nor was it even conceivable that it could have
taken place. If they accepted that theory they would have
to regard the lower carboniferous rocks of Scotland as the
same thing as the coal measures of England and the
Stephanian rocks of central France as the same as the
Westphalian rocks of Northern France and Belgium. There
was abundant evidence that those hypotheses were false.
With regard to the upper series which both Mr. Bolton
and Prof. Boyd Dawkins declared to be the Pennant grit,
he wished to refresh the memories of the members as to
what was found in the Somerset coal field. In the top
measures there was a great thickness of productive beds
separated by a well-marked and very constant horizon of
red shales, >about 200 ft. thick. In Kent there was no trace
of red shales, but he did not emphasise that point, because
probably the higher beds of Kent were underneath the
English Channel, and had not yet been reached. Then
below that productive series there was a great thickness,
2,000 ft. or more of Pennant grit which was always entirely
unproductive except in the lower part which, lithologically,
was a rock, and was quite unmistakable. In last year’s
paper he pointed out that he knew of no bed of sandstone
in Kent which exceeded 300 ft.; he had examined practically
every boring in the centre and south of Kent, and he had
never met a really massive sandstone of any thickness
beyond 100 or 200 ft. Where did Mr. Bolton get his great
thickness of sandstone? If he was going to add together
the sandstone beds proved in the different borings, surely
he must first correlate them. But he expressly told them
that he had not attempted the correlation. It was hardly
conceivable that anyone could make such assertions without
at least having made a provisional temporary correlation.
The coal measures of Kent contained sandstone and shale in,
as a rule, about equal proportions. There were a few
borings which were a little more sandy than shaly, but he
knew of no boring where the sandstone amounted to 50 per
cent, of the whole measures. The fauna of those higher
beds no doubt did occur in the Farrington series and the
Pennant grit, but if it was looked into they would find it
was just as widely distributed among the whole of the beds
in the coal measures as was the flora of the lower beds
to which he had referred. To his mind, the fauna evidence
relied upon by Mr. Bolton with regard to the horizon was
worthless. What was required with regard to the fresh
water mollusca was more studies of the vertical range of
those fossils, and especially of the stages in the evolution
of the groups during the carboniferous period. It was quite
idle to pretend that at the present time those stages in the
evolution of groups had been recognised or worked out, and
until that had been done it was little short of presumptuous
to attempt to zone an entirely concealed coal field by means
of these fossils. With regard to the plant evidence he need

hardly remind the members that the fundamental principles
were perfected long ago.

The assertion that the highest known beds belonged to the
transition coal measures did not rest on his own words; it was
made many years ago by the greatest authority on the coal
fields of France, Prof. Zeiller, of Paris. The term which
Prof. Boyd Dawkins, when criticising his paper, disliked so
much, was not his term; it was invented many years ago.
All he had done was to show that the transition coal measures
proved by Zeiller in the original borings at Dover extended
for a considerable distance to the north, and that further
north still they met with a lower horizon the middle coal
measures. Of course, each was a stage lower than was postu-
lated by Mr. Bolton in his paper. He did not propose to
enter into the floral matters, but he should like to say that
those conclusions rested on an entirely different philosophy
to that which was made use of in the paper under discussion.
To those who were inclined to place the fauna evidence on a
higher plane than the floral, he would point out that among
the fossil flora (excepting a few extremely stereotyped forms,
such as stigmaria, which did not affect the question at all),
none were known which had anything like the vertical range
in the whole of the carboniferous period than. had these
particular types indicated by Mr. Bolton, on which he had
relied for his horizon. Therefore, he regretfully concluded
that the paper threw no light at all on the many problems
which still remained in connection with this concealed coal
field.

Mr. E. O. Forster Brown (London), in the course of a
written contribution, said he had read Mr. Bolton’s paper
with much interest, particularly that portion relating to the
stratigraphy of the coal field. It was unfortunate that Mr.
Bolton had not seen his way to avail himself of all the infor-
mation obtainable on which to base his conclusions. He had
dealt with the results of 15 boreholes, whereas more than
half as many again had been put down in the field, several
of which passed through the coal measures into the carboni-
ferous limestone. He was in agreement with Mr. Bolton’s
general conclusions on the contour of the carboniferous lime-
stone floor where proved by borings, but did not quite follow
why Mr. Bolton had flattened the contours of that floor to
such an extent in the Barf-restone. Maydensole, Waldershare,
and Stonehall area, where the carboniferous limestone was
not proved by borings. In contouring the floor on a.plan, he
found verv little evidence of any easing up of the dip where
the floor had been proved in the deeper borings, either in a
south-westerly direction from the Ripple-Oxney neighbour-
hood, or in a southerly direction from the Trapham-Stod-
marsh-Walmestone neighbourhood. Possibly he was misled
as to the shape of the plaster model by the photograph, but
he did not think so, and he was strengthened in this view
by the remarks on the Stonehall boring. Mr. Bolton stated
that the limestone floor at that point could not be much, if at
all, deeper than 3,700ft., and then.went on to say that, in
constructing a model of the carboniferous limestone floor, it
did not appear possible to carry its surface down to the
4.000 ft. datum level on the south side of the Dover-Canter-
bury-Sandwich triangle. He could not quite follow what had
led Mr. Bolton to that conclusion. The evidence seemed, if
anvthip’SL to point the other way.

Turning to the subdivision of the coal measures into an
upper series of sandstones, binds and coals and a lower series
of shales, binds and coals, he thought that was a preferable
and certainlv a simpler subdivision from a practical point.of
view than the one adopted by Dr. Arber. Mr. Bolton said,
“It is probable that the lower beds successively overlay each
other upon the limestone from the south-west to the north-
east,” and, in referring to the Kent lower series, “ as they
evidently seem to overlap in the north-east, a much greater
development of them may yet be found in the south and
west, but at a great depth.” From those statements, it
appeared tha4 the author was of opinion that the coal
measures were not conformable to the carboniferous limestone.
If that were so, it was a very important point.

He could not reconcile those statements, however, with the
remarks on the Stonehall boring (the most south-westerly
boring dealt with). Tn regard to these, he asserted that
“ the lower shales and binds were not reached in the boring
at Stonehall, although the coal measures were penetrated to a
depth of 3.470 ft.. and as the limestone floor at that point
could not be much, if at all. deeper than 3.700ft.. it was
highly improbable that the whole of the lower coal measures
were anywhere present.” If his conclusions were correct,
the maximum thickness of lower coal measures that could
exist at Stonehall would be 230 ft.. whereas further north
and east, at Barfrestone, Ripple, and Oxney, Mr. Bolton
had given thicknesses to that series in excess of that figure.
That seemed to contradict altogether the previous statement
that a greater thickness of lower series would probably be
found to the south and west.

He was very much struck, in the description of the Stone-
hall boring, bv the repeated reference to the occurrence of
thick coals. It was a well known fact that the borehole
records in Kent, almost without exception, showed, compara-
tively few thick seams in the upper sandstone series, and a
comparatively large number of thick coal seams in the lower
shale and bind series. No shafts in the conntv had yet
reached the lower series; the shaft developments in the upper
series, however, had gone a long wav to confirm the limited
number of thick coal seams present in the upner series, as
indicated by the original borehole records. The Stonehall
boring, according to Mr. Bolton, had proved nothing but
upper series, which, nevertheless, at that point, appeared to
be full of thick coals. They were referred to at nine
separate horizons, and the question naturally arose whether
the geological conditions at that boring were altogether
normal, and such that reliable conclusions could be based on
them.

Tn that connection he observed that on fig. 1. plate 7. the
Chilton borehole, close to Stonehall, was shown, although that
borehole was nowhere referred to in the paper. Tn v;ew of
its proximity to the Stonehall boring, it would be interesting
to have Mr. Bolton’s views on the measures proved there, and
the extent to which they bore out his views on the Stonehall
boring, the probable relative thicknesses of the upper and
lower series, and the depth to the carboniferous limestone
floor in the Stonehall neighbourhood.

The discussion was again adjourned.

North Staffordshire Institute of Mining and Mechanical
Engineers.—The 43rd annual meeting will be held at the
Central School of Science and Technology. Stoke-on-Trent,
on Monday, at 4 p.m. The president will take the chair, and
will deliver an address. The following papers will be open
for discussion :—” Coal Dust Explosions,” by Mr. J. D.
Morgan; “ Notes on Sampling.” by Mr. T. W. D. Gregory,
F.C.S.

MIDLAND COUNTIES INSTITUTION
OF ENGINEERS.

ANNUAL MEETING AT NOTTINGHAM.

The annual meeting of the Midland Counties
Institution of Engineers was held last Saturday at the
University College, Nottingham, under the presidency of
Mr. G. S. Bragge (Moseley).

The Acting Secretary (Mr. P. W. Lewis) announced
that Mr. Thomas Henry Harwood, mining engineer, of
London-road, Derby, had been elected a member, and
Mr. Jno. Parker, under-manager, Pleasley Colliery, near
Mansfield, an associate of the institution.

Annual Report.

On the motion of the President, .the annual report
and statement of accounts were taken as read and
adopted. The council expressed its regret that a
decrease was again shown in the membership,
the total number on the roll being 356, as com-
pared with 367 last year, and 375 in the year before.
On the other hand, the financial position showed a steady
improvement, the bank balance being 42718 14s. 3d., as
compared with £519 3s. 7d. last year, and £443 14s. 2d.
in the year before. The report adds that the world
war which broke out during the past year has not been
without its effect on the institution. To the list the
Midland Counties Institution has contributed the names
of 23 members, one associate member, four associates,
and 10 students. The council regrets to report that two
members—Messrs. James Lancaster and W. Hutton-
Williams; and two students—Messrs. N. C. Parry and
S. P. D. Thomson—have been killed in action.

Election of Officers.

Messrs. Evans and Todd, who were appointed to act
as scrutineers of the ballot papers, reported that the
election of officers for the year 1915-16 had resulted as
follpws :—President, Mr. G. S. Bragge. Vice-presi-
dents : Messrs. H. O. Bishop, R. H. F. Hepplewhite,
B. McLaren, P. Beaumont, E. E. Bramall, and T. G.
Lees. Councillors : Maj. T. P. Barber, Lieut. H. Dennis
Bayley, Messrs. J. Bingley, R. W. Cuthbertson, R. H.
Ferens, J. Mein, G. Spencer, W. eE. Walker, C.
Dickinson, C. R. Hewitt, C. M. Haslam, and F. N.
Iliffe. Ex-officio members of the council for ensuing
year: Lieut.-Col. R. P. Leach, Messrs. J. A. Longden,
M. H. Mills, W. D. Holford, Maurice Deacon, W. B.
M. Jackson, W. G. Phillips, G. J. Binns, W. Hay,
J. Piggford, J. P. Houfton, W. H. Hepplewhite, and
H. E. Mitton.

President’s Address.

Mr. G. S. Bragge, in a short presidential address, thanked
members for the honour they had done him in re-electing him,
and for support they had given him during the past year. In
times such as the present it was impossible that an institu-
tion like theirs should go on with the vigour usual under
ordinary conditions—in fact, it was scarcely desirable that
it should. In saying that, he did not wish to discourage
them from writing papers—on the contrary, he appealed to
them for all the help they could give in that direction.
He admitted the difficulties in the way, but the incentives
offered in the valuable prizes given by past-presidents ought
to lead to more papers being forthcoming. He would also
like to impress upon the younger members the fact that
the preparation of a paper would show them where their
knowledge was deficient, and thus indirectly prove a means
of instruction to them. Many of the members—he trusted
nearly every one of them—had sons, brothers, or other
relatives at the front, and were naturally somewhat pre-
occupied, while all actively engaged in their profession had
special difficulties to contend witn in their work in the way
oi shortage of men and material, as foreshadowed in his
remarks a year ago. Those difficulties, no doubt, would
increase. The output of their pits had no doubt suffered
in a greater proportion owing to the fact of men of the best
age and physique having enlisted. The question of timber
or other roof supports, which had been and still was, the
subject of interesting and instructive discussions at their
meetings, was still a matter of anxiety, and from his own
experience he should say that this item was now more than
double the cost of what it was some months ago. It was
gratifying, but only what he expected, to see in Mr.
Johnstone’s report that no cases of accident had been
reported in which the supply of timber or other supports to
the miners had been reduced on account of the cost. In
the inspector’s report of the Yorkshire and North Midland
Division the same thing was alluded to. With regard to
fatal accidents, the reduction of which was one of their
chief concerns, the figures were just about as usual. In
this matter of the average expectation of accidents he read
a good many years ago that M. Eiffel (whose fame as an
all-round engineer had been somewhat obscured by the
celebrity of his Tower at Paris) proved from the com-
parison of a number of large engineering and constructional
works that in the expenditure of a certain number of francs
on such works, one fatal accident on the average could be
expected. It would be interesting to compare it with the
results at collieries in England. Without detaining them
longer, he would like to emphasise what he said a year
ago about the necessity of being prepared to meet the
altered conditions which would be sure to arise in their
own profession, as well as in most other industries, when
the war was over. Being old enough to remember the effect
of the Franco-German war of 1870-71 on the trade of this
country, when a few years of great activity spent in replen-
ishing the exhausted markets of the belligerents wa-s
followed by a very long period of depression, he confessed
to viewing the future with some apprehension. In 1871,
Germany was not a great industrial and manufacturing
nation, as she is now, and when peace was concluded she
would be compelled to compete with us even more than
in the past for the world’s trade. All the more reason, there-
fore, for them to be prepared to meet this competition by
keeping their pits in good order.