October 8, 1915.

THE COLLIERY GUARDIAN

727

so satisfied with the first that they had installed a
second. He was quite of Mr. Laverick’s opinion that
in that way, and possibly by some adaptation of gas
engines, compressed air w’ould be produced very much
more cheaply. In the spring of last year he was very
well satisfied with using electricity for coal cutting and
conveying, but, from circumstances which would be
well known to everybody, and very much against his
will, he was compelled to adopt compressed air in lieu
of the very much more economical electrical power.
That, he supposed, was the position of many people,
who would prefer to use electricity, but who had no
alternative but to use compressed air.

The President, in adjourning the discussion, hoped
it would be carried on to a considerable extent, because
the subject was one of the most interesting that had to
do with mining.

Earth Movements on Coal Measures.

The meeting next discussed Prof. W. G. Fearnsides’
paper on “ Some Effects of Earth Movement on the Coal
Measures of the Sheffield District,” which also was read
at the annual meeting of the Institution of Mining
Engineers on September 15.

Prof. Fearnsides exhibited a number of specimens of
mingled coal and rock to illustrate his paper. One of
the specimens illustrated two or three hundred little
faults. He thought that anyone who examined it would
admit that the crunching of which he had spoken was
illustrated by such a specimen. None of the specimens
produced could in any way be explained on the hypo-
thesis that washouts—or rock faults, as he preferred to
call them—were sedimentary formations. He adopted
the idea'of fault jumbles for all such cases as he had
seen : he had not yet had his attention drawn to any
particular case of a rock fault which required the con-
temporaneous erosion explanation. He should not only
like to know where such cases were, but, if possible, to
trace the direction of the channel which was supposed
. to have been cut across the sediment.

He went on to refer to section (1) of the “ summary
of outstanding facts ” contained in his paper. This
stated : “ Rock faults affect individual coal seams, and
the existence of a rock fault in one seam is no primd
facie evidence that the other seams in the same pro-
perty are likely to be similarly affected.” Although it
did not appear that a rock fault which affected one seam
would affect the other seams immediately vertically
underneath, it did seem that there were regions where
belts crossed a coal field, or appeared as patches, and
that, wherever they got seams associated with a change
in the general geology of measures, all the seams were
likely to be broken up by this rock faulting. In South
Staffordshire he had had his attention called to two or
three examples. In the characteristic example at
Pleasley and Teversall, in Derbyshire, it appeared that,
when the seams came up to a particular region or belt of
country having this general trend, all of them did some-
thing queer. Some of them thickened, some of them
thinned, some were broken up, and some contained bits
of rubbish interpolated among the coal; it seemed that
the whole strip of country had not been a very good one
from the point of view of the coal miner. It had also
been mentioned to him that in the Yorkshire coal field
the examples best known to colliery managers occurred
in regions where they generally looked for a change in
the seams. West Yorkshire and South Yorkshire had
been divided up by colliery people more definitely, he
thought, than they could be by the geologist, but they
did get a change from the Barnsley seam to the Warren
House along a line, and it appeared that along that line
other seams than the Barnsley underwent a modification,
and he believed that the whole coal field was liable to
these break-ups. It might be that this was a sedimen-
tary break-up. It might be that the change took place
at the time of deposition. In No. 3 of his outstanding
facts, he said, “ Rock faults are most frequent in coal
seams which have a roof of weak clod or bind, forming
a thin ripping between the top coal and a much stronger
overlying mass of stone bind or sandstone.” That was
a point on which he laid considerable stress.

Mr. E. W. Thirkell said he did not think that the
lateral pressure had as much to do with the matter as
Prof. Fearnsides would like them to think. He sug-
gested that if they used the word “ washout,” far more
men would understand what they were talking about
than if they spoke of “ rock faults.” At Aldwarke they
had two washouts. One was in the Barnsley bed,
extending over several hundred acres, and the other in
the Parkgate bed, some 250 yds. below, also extending
over several hundred acres. Although the one did not
immediately overlie the other, still they almost over-
lapped at one particular point. In working the Park-
gate seam, coming events did undoubtedly cast their
shadows before. They found that the seam gradually
altered its nature. They began to find little streaks of
sandstone (of which the roof was composed) coming into
the seam, like little leaders, and sometimes they also
had nodules of rock. But in all cases where they had
these thin streaks the seam of coal was thin. Say the
seam was 5 ft. thick. Six inches from the top they
found a streak of sandstone coming in. That streak
might run for a yard, and then the seam dropped from
5 ft. to 4 ft. 6 in. They went on a little further, and
came across another streak, and the seam dropped again,
and so on, until finally the seam dropped to about 12 in.
thick. He called attention to some sections he had
noticed. One was where they had a foreign material
coming in from the top of the seam—say, two-thirds of
the thickness of the seam, 3 ft. thick and about 6 or 8 in.
wide, much in the same way as they could see in a
peat bog to-day. If they went through such a bog they

would find that a stream of water had made a little
cutting, not completely through the bog, but so far
down. But they had another phenomenon, which was
that the same sort of thing occurred from the bottom.
The cutting, instead of coming down from the top, came
up from the floor. When it came from the top, the
space, or the cutting, was filled in with a roof material,
and when it came up from the floor it was filled in with
a floor material. In another case in the Parkgate seam
they had a band of sandstone, about 6 in. thick, which
came clean through from top to bottom. It was rock,
the same material that the roof was composed of, and
as far as he remembered, it stopped dead short at the
floor, and did not go through the floor. They had
another case in the Swallow Wood seam. In that seam
the roof was invariably composed of binds, the rock was
an unknown thing, but in one particular instance they
had an isolated piece of rock. There were no leaders,
no streaks, nothing to indicate how the rock came
there, but there it was. It was about 6 ft. or 8 ft. long,
3 ft. or 4 ft. thick, and 3 ft. or 4 ft. high, probably. He
went on to refer to the remarks of Mr. Wood concerning
the great rises of the rivers in China, and their forma-
tion of new channels. By taking notice of what occurred
in various parts of the world, he thought they could draw
conclusions as to what would be likely to occur in the
remote past. He suggested that sections of anything
considered extraordinary should be sent to the sections
committee of the institute. If they were all put together
they would form a valuable collection.

Prof. Kendall said the case of Thrybergh Colliery
was the subject of a paper by Mr. F. E. Middleton to
the Geological Society of London some years ago. In
the discussion of that paper, he (the speaker) drew atten-
tion to tMe close connection that he had observed in
many cases between the distribution of the wrashouts, or
“ wants,” and the faulting of the district. The case
at Thrybergh was one of that kind, where they had a
“want” in two great seams over hundreds of acres.
He did not condemn Prof. Fearnsides’ hypothesis, but
he did not want to commit himself to any definite
opinion. Thrusting, by which he meant the pushing
together of the strata, had certainly taken place. He
criticised some of the diagrams, one of which was meant
to represent the great wash, so-called, in the Haigh Moor
seam, but it was nothing of the kind. He learned, as he
anticipated, that the great want was away down, and
that the diagram showed the collateral effects, or the
accompaniments, of the wash, not the want itself. This
was a very material thing, and seemed to him to have an
interesting bearing upon the hypothesis put forward.
Prof. Howell, known to the older generation as a veteran
geologist, in 1864 described a wash or want in the
Pemberton Five-foot coal in the Wigan district. In that
case, what was known as proud coal occurred on both
sides of the wash, and he suggested that the relatively
rigid mass of sandstone that filled the intervening space
had acted as a wedge, and pushed coal out so as to
increase its thickness at the sides. He (Prof. Kendall)
did not put that forward as a hypothesis to meet all
occasions, but he suggested that it was worthy of con-
sideration whether the overthrusts were not the effects
of the wash or want, and not the cause—that, if they
had a great mass of sandstone or sand substituted for a
certain amount of coal, or of the pulp that formed coal,
then, when superincumbent pressures were brought to
bear, the unyielding mass tended to push out the more
yielding material. That was a view of the matter that
he thought was well worth considering. They must
bear in mind that, adjacent to the area dealt with in
Prof. Fearnsides’ diagram, was a very large area, at
present not fully penetrated, in which the Haigh Moor
seam was missing. Another professorial friend of his
told him of an occurrence that he witnessed which might
throw some further light upon the occurrence of the
enlargement of the coal seams along the margin of a
wash or want. There was a cloud burst that swept
across an area of peat. Now those who had studied
peat bogs knew that the peat on the surface was usually
in a very tough and fibrous conditions, but down below it
became somewhat pulpy, and finally it might become a
buttery, carbonaceous slime. Apparently the stream of
water, rushing over such a surface, exercised pressure on
the pulpy layer beneath, and burst the upper layer, which
as the water ran down, was turned back. His friend
said that the margins were just as if they had been
turned by a plough. Prof. Kendall also referred to his
own investigations on the subjects of washes and cleat,
and to the fact of Prof. Fearnsides having come into the
same field before his own researches were completed.
He appealed to the members of the institute not to allow
his investigations to be prejudiced by this.

Mr. Blake Walker said there were evidently two
fields of opinion, and it would be unfortunate if the
other side, which Prof. Kendall championed, were not
adequately brought forward. He himself thought that
there was a great deal in some of the large washouts to
justify the erosion theory. On the other hand, there
were a great many questions with regard to earth move-
ments. They must all regret the absence of a great
deal of information which might have been available if
the managers of different collieries had carefully pre-
served records of what they had observed in connection
with these occurrences. But, if the past was irre-
coverable, they might try to impress upon all who took
an intelligent interest in coal mining the value of pre-
serving and furnishing to the institute any data they
might have which threw light on the various phenomena.

Mr. Thirkell said he would do his best to get all the
information he could upon the subject of washouts. At
his colliery they had knowledge of that at Thrybergh
Hall, also of one in the Barnsley seam at another
colliery, and one in the Parkgate seam at their own.

They had not a Swallow Wood. Unfortunately, from a
scientific point of view, they had not got into that parti-
cular area in the Swallow Wood seam. He agreed with
what had been said, that there was no analogy between
the Barnsley and Parkgate washouts. They might have
a washout in the Barnsley bed which was quite local to
that bed, and might have nothing to do with a washout
of a similar nature in a seam 250 yds. below it which
took place hundreds of years earlier.

Mr. W. H. Ball said that some years ago he was at
some collieries in Cumberland, where they worked from
11 different seams. There was a washout in what they
termed the “ Little main,” but in three or four seams
directly above it there was no sign whatever of a
thinning of the coal.

Mr. T. Beach said at Hemsworth they had not had
any washouts at present. At Whit wood Collieries, in
the Haigh Moor seam, there was a washout which went
east and west, roughly speaking, while in the Silkstone
seam, which was a good distance below, there was one
which ran almost at right angles to that in the Haigh
Moor.

Prof. Kendall said the peculiarity of the Silkstone
seam at Whitwood, as he understood it, was not that
the seam was washed, but that it was a split seam. The
bottoms went straight on, and the upper part of the
seam arched over.

Mr. Laverick mentioned a case that he came across in
Warwickshire of a washout in a seam 26 ft. thick. Head-
ings were driven through to the coal on the other side,
and the top part of the seam was worked. Everybody
thought that the whole seam had gone. Some few
years afterwards, however, it occurred to somebody to
wonder whether there was any coal underneath, and it
was found and worked. It was practically a third of
the seam that had been washed away or moved in some
way.

Mr. Walker referred to the possible relation between
these earth movements, or washouts, and marked
faulty ground. At South Kirkby there was the Bads-
worth fault, a breadth of very faulty ground, on one
side of which the seams were of the South Yorkshire
character, and on the other side of the West Yorkshire
character. The same thing applied to a certain extent
to the Rotherham area, where they had these occurrences
closely associated with broken and disturbed ground.
That broken and disturbed ground, of course, was an
evidence of earth movement and fracture. If there was
a connection which could be explained between the frac-
ture of the strata, the dislocation of the whole series of
beds, and, in the immediate proximity, these phenomena
of seams and rock being intermixed—and, where they
had a perfectly undisturbed coal field, they did not, as a
rule, meet with these washouts—he thought that con-
junction of circumstances might be discussed, if not
explained.

Mr. W. D. Lloyd said fig. 2, which Prof. Kendall had
spoken of as misleading, would, if extended to the south-
east, enter an area in which so far they had not found any
coal at all.

Prof. Fearnsides, in reply to the discussion, said Mr.
Thirkell had mentioned one new thing — the Swallow
Wood fault. He had not previously had a record of a
washout or rock fault in that seam. As to the big mass
of sandstone, absolutely apart, which Mr. Thirkell men-
tioned, he should like to know how far they would have
to go in the section, above and below, to find a lump of
sandstone like it. He imagined that if they went 15 ft.
up or 15 ft. down they would find a rock which could
supply it. That was a matter of great importance. He
should very much welcome the suggestion that there
should be a committee which would put data with regard
to these phenomena on record. The president of the
Federated Institution, at the end of the Leeds meeting,
said he thought the matter ought to be ventilated not
only for the Yorkshire coal field, but for all others, and
perhaps a joint sub-committee of some sort might gather
the evidence. They wanted to know where all the faults
were, and to put the lines on a map. They did not want
to give away information which would spoil the game of
men who were exploring the ground underneath. Some-
times the knowledge of a washout in an area was not a
thing that one wanted to make public. Like Prof.
Kendall, he was not an advocate of one explanation
alone. He was simply giving an explanation of the
examples that had been brought to his notice.

Grimsby Coal Exports.—The following is the official return
of the quantities of coal exported from Grimsby during the
week ending October 1 :—Foreign : To Esbjerg, 800 tons;
Gefle, 1,594; Gothenburg, 2,047; Oxelosund, 2,196: Reyk-
javik, 1,478; Trouville, 571; total, 8,686 tons; against 18,639
tons in the corresponding week of last year. Coastwise : To
Yarmouth, 560 tons; and London, 1,800 tons: total. 2,360
tons, compared with none during the corresponding week of
last year.

North of England Institute of Mining and Mechanical
Engineers.—A general meeting of the institute will be held
in the Wood Memorial Hall, Newcastle-upon-Tvne, at two
o’clock, to-morrow (Saturday). The agenda includes a pre-
sentation of engravings and lamps by Dr. J. B. Simpson;
and presidential address by Mr. T. Y. Greener. The follow-
ing paper will be read or taken as read : ‘‘ Modern American
Coal Mining Methods, with some Comparisons,” by Mr.
Samuel Dean.