June 22, 1917.

THE COLLIERY GUARDIAN.

1169

sure to set up in the stacks of coal, very much indepen-
dent of their dimensions. The coal contained no pyrites,
and analyses showed a very small quantity of sulphur.
The coal all over the Kilsyth area is overlain by an
intrusive whinstone varying in thickness from 120 to
130 ft. thick. This whinstone is not always found in the
same geological horizon, and it spoils the value of any
coal near to it either above or below. In one particular
area in the district it makes one of the seams below it a
valuable anthracite coal, but this only occurs where the
thickness of the whinstone and the distance it lies above
the coal remain constant. If any change occurs in the
distance and thickness, then the quality of the coal
changes. The coking coal seam is, however, too far
below this intrusive whinstone to be affected by it. Large
vertical whin gaws or dykes run through the district
from east to west. These gaws vary in thickness, but
are generally about 100 ft. thick. . The seams of coal,
whenever they approach to within 100 ft. of either side
of these gaws, begin to change their quality, the fixed
carbon increasing and the volatile matters reducing. The
ash also tends to increase, and so does the sulphur to a
small extent. The coking coal seam, free from the
influence of either the intrusive whinstone or the whin
dykes, has about 30 per cent, of volatile matters, and
makes an excellent coke. Within 100 ft. on either side
of the whin dykes the coal gradually changes from its
ordinary condition to a hard burnt material, similar to
coke, but black in colour. Many roads have been driven
through these whin dykes, but only in one case at Bar-
wood had we the following experience. As the road
approached the whin gaw, the coal sometimes heated
after being exposed to the air, but never fired. On the
other side of the gaw the coal about 15 ft. away from it
immediately got very hot on being taken down, and when
it was in the tub became red hot. It was only at this
point that we had such an experience. The coal was
very dry, and went almost into powder, and rapid oxida-
tion must have been the cause of its heating and firing
in so short a time. Of'course, this incident was special
and local, and not common to the seam generally, but
the fact that, although there was no pyrites and little
sulphur content in the coal, it was liable to spontaneous
combustion when stacked, goes to prove that there are
other causes for spontaneous combustion than the mere
existence of pyrites. Some further investigations at the
Doncaster laboratory or other laboratories which may be
instituted in other parts of the British coal field, may
lead to the discovery of that other, material which Dr.
Haldane suggests may exist in coal, which might, under
certain conditions, produce spontaneous combustion.

The incident was very difficult of explanation at the
time, but Dr. Haldane’s investigations had made the
reasons for what occurred tolerably plain. That coal
in a fine state of subdivision was more likely to take
fire than large pieces had long been supposed, and he
recently had reason to be unpleasantly reminded of the
fact by the outbreak of a fire in a washer house, clue,
beyond doubt, to an unusual accumulation of dust
being allowed on a wooden floor, and in contact with
the wooden casing of a riddle; but now at Doncaster
that had been proved and accurately measured. A
point which had not been touched upon in the paper
was that coking coal lost its coking property to some
extent after exposure to air for some time. The
better the coking coal, the longer it would remain a
coking coal after exposure. There were many coking
coals, but with comparatively few did exposure destroy
the coking property. The relation between that and
those other investigations might be the subject of
further investigation at some future time. The fact
that laboratory low-temperature combustion of coal
failed to account for the quantity of carbon dioxide
found in return airways and in blackdamp was new.
If the practice of frequent and systematic analysis of
mine air were more prevalent than it was now, some
light might be thrown on this question. He had
several times elsewhere suggested that laboratories
similar to that at Doncaster might with advantage be
established in other districts, perhaps in connection
with the central rescue stations. Some supervision,
by a highly-trained scientific man, of the apparatus
dealt with at those somewhat dangerous institutions
would be highly beneficial. He was of opinion that in
most districts the managers would very soon appre-
ciate the value of the services of an accessible man for
the analyses, at regular intervals, of mine air samples
taken by him, or in accordance with their instructions,
and for many other purposes. Those services should
be paid for by the particular colliery making use of
them, and in that way the laboratories he had sug-
gested would be to some extent self-supporting. At
the same time, the scientific man in charge should
have a certain amount of time free to carry on original
researches, some of which had been suggested in Dr.
Haldane’s paper, and he therefore thought that those
laboratories should be affiliated to a central research
laboratory, and the whole scheme organised to fit into
the scheme for industrial research recently inaugu-
rated by the Government. The council had the matter
in hand at present, and possibly at the next meeting
he would be in a position to report some progress in
that direction. He thought he was right in saying
that one object Dr. Haldane had in view when he
drafted his paper was to initiate a good discussion by
mining engineers in daily contact with many of the
points raised; and he sincerely hoped that many mem-
bers would take part in the discussion, and that, in
spite of the heavy strain upon all of them through war
conditions, many others would find time to send in
written communications for the meeting in September
if they were not able to attend in person. Dr. Haldane
was inclined to minimise his share in the work done at
Doncaster, but he (the speaker) was certain he was
reflecting the views of all the members when he said
that they clearly recognised what Dr. Haldane had
done for them ; he did not think he was over-stating
the case when he said that the conversion of an unusu-
ally dangerous type of colliery into a comparatively
safe one was primarily due to Dr. Haldane. He there-
fore had pleasure in proposing the following
resolution: —

The Institution of Mining Engineers desire to place on
record their high appreciation of the work done at the
Doncaster Coal Owners’ Research Laboratory during the
last four years, and to acknowledge the services ren-

dered to the coal trade by the late Sir Arthur Markham
and Mr. T. W. Fryar, who initiated the scheme, and
Dr. Haldane and his assistants, who carried it out. The
Institution of Mining Engineers are satisfied that the
close alliance between pure science and practical work
at Doncaster has done much to lessen the dangers of coal
mining.

Col. W. C. Blackett (Durham) said that he would
have very great pleasure in seconding the motion.
The number of points which had been solved by Dr.
Haldane, Mr. Winmill, and his assistants, had cer-
tainly cleared up mysteries at the collieries. As Dr.
Haldane read his paper, one mystery came back to his
(the speaker’s) mind, which occurred in connection
with a heap of refuse matter at one of the collieries.
It was not a large heap—perhaps five or six times the
size of that room—-and consisted mostly of shales, in
which other stone was mixed. To his knowledge—not
his actual personal knowledge, but from records — it
had lain for 30 years in that site near the colliery, and
nothing had happened. In more recent years another
heap had been started some distance away, and that
heap spontaneously fired. Although they did their
best to put it out, the fire spread, and part of its heat
spread in the direction of the older heap, although
they were not aware of it at the time. In fact, it
showed no signs at all of spreading in that direction,
but it must have done so, because evidently, after
lying dormant 30 years, the increase of heat in its
neighbourhood appears to have started spontaneous
combustion in the old heap, and it burnt merrily away
until it was completely reduced to a calcined mass, and
turned, as all shales did, a bright red colour. With
regard to the president’s suggestion of the use of
rescue stations, he thought it a most excellent one. So
far as the North of England was concerned, they had
more or less unofficially begun something of the kind,
and had a small and simple laboratory in connection
with their central station. In connection with that,
he might say that their superintendent, who was by no
means a skilled chemist — he merely dabbled in
chemistry, and it would be to their advantage to have
a skilled chemist for that particular work—had experi-
mented with the use of solutions of soda ash put
through the boreholes into those heaps w’hich were
igniting spontaneously, and he believed it had been
found that the use of those solutions tended to stop the
incipient conflagration of the heaps. Perhaps Dr.
Haldane and his staff might give them some further
insight as to whether that was a likely action to have
taken place, or whether Mr. Mills was on wrong lines
in making those experiments. With regard to not
accounting for the amount of carbon dioxide in the
air of mines from coal, he would remind the experi-
menters that there were in the mine other materials
besides coal from which that might arise. It might be
possible that some of the shales in connection w’ith the
coal seams might develop far more carbon dioxide than
the coal did, and not only the shales, but also aqueous
solutions arising from those shales. They all knew
that in the neighbourhood of the heaps, as they lay
one got enormous quantities of iron oxide, and so on ;
and some of the solutions which were formed in the
mines might throw’ some light upon that particular
subject. He would also like to mention, in connection
with one of the mysteries of mining, that in opening
out one of their coking seams in the North of Eng-
land they found accumulated pools. There was not a
great amount of water, but in the shallow parts of
the galleries driven there were pools of water, and in
certain parts of the seam those pools accumulated a
layer of jelly-like material over them, like a coating
of oil on the water. One could put one’s hand under
those sheets of jelly stuff, and lift them up. If one
dried it, if one put some of it between the leaves of a
notebook, it dried exactly like paper and with a
similar consistency. He had been very much puzzled
as to what that could be, and he had sent bottles of it
—it was a good many years ago now—to the local
College of Science in Newcastle, in which Prof. Louis
took so much part, and tried to ascertain from them
what exactly the stuff was. Whether it was that they
were not able to throw’ sufficient light on it, or whether
it was that he was not capable of receiving the light,
he did not know, but he never understood the explana-
tion which they had given, and he could not possibly
remember it at the present moment. He thought it
lay in the direction of some form of micro-organism ;
but how that micro-organism could have arisen in a
virgin mine newly opened out, or why, having arisen,
it could carry on in that peculiar way, he had never
got to know. He thought that that was a subject
which was worth some examination.

Mr. H. Eustace Mitton (Codnor, Derby) wished to
associate himself with the resolution before the meet-
ing, and especially as to the reference which had been
made by the president and Dr. Haldane to the memory
of the late Sir Arthur Markham and Mr. Fryar.
Having served under Sir Arthur Markham for many
years, and having lived as a near neighbour of Mr.
Fryar, he felt what a great loss the mining industry
had sustained from the death of those two gentlemen.
He thought that the paper was of very great value.
He would have liked to see it headed to embrace the
subject of underground fires entirely, and not simply
headed “ The Spontaneous Firing of Coal.” At the
present time he had—and, like the poor, it was always
with him—a mine in which the remedies suggested at
the end of the paper were most rigidly carried out.
Every bit of coal which he could possibly get was sent
out of the mine, and one of the rules which had been
made, and which the manager and he enforced most
strongly, was that no gob was to have any timber or
any coal, if possible, left in it. In spite of their pre-
cautions, for some reason unknown, outbreaks of gob-
fire periodically took place. In the same seam, work-
ing with only a barrier 44 yds. apart, there had never
been a single instance of a gob-fire; yet in that mine
within a period sometimes of one or two years gob-fires
had occurred. He had discovered a very interesting
point—namely, that those fires always started in the
strata immediately below the line of coal, and on the
dip side of the mine. He would very much like the

paper to be kept open for further discussion, in order
that he might write a short account of the trouble
which he had had in his own mines, and bring it for-
ward at a future meeting. Probably Dr. Haldane
would be able to throw some further light upon it.

Mr. C. Augustus Carlow (Leven) also desired to
associate himself with all that had been said, and
thanked the author for the information which he had
given. It was only those who had the anxiety and
the worry of working among fires regularly and every
day who properly appreciated the value of any infor-
mation such as so able a scientist as Dr. Haldane was
able to put before them. Dr. Haldane had asked that
practical application might be referred to during the
discussion, and, strangely enough, he (Mr. Carlow)
could point to fires (of all- the kinds and under all the
circumstances to which the author had referred) which
had come within his own experience in his own
collieries in Fifeshire. For instance, in regard to fires
on the surface in refuse heaps, a very peculiar thing
might be seen at one of the collieries. One found a
very high heap of refuse standing unburnt and a com-
paratively low heap of the same refuse merrily burn-
ing away. If one asked the manager or the foreman
on the surface, he would probably say that “ washery
red refuse,” as he called it, was the cause of the fire.
He wished the members to understand that it was
exactly the same refuse which went into the washer as
that which went on the heap, but in passing through
the washer one got small pieces of fireclay thoroughly
soaked in water, and when those were put upon the
same bin as the larger pieces, they choked up the air
space and prevented the air from driving its way
through the heap, and immediately a fire occurred.
The people at the colliery thought that it was some
peculiar feature in the washery which made the refuse
tend to fire. It had been a peculiar phenomenon for
some years, but there it was, and he felt sure that it
was due to the small water-soaked, spongy refuse
coming from the washery, and the fireclays, etc., which
were put upon the heap and stopped the passage of
air; while in the old heap which was put down before
the washery was thought of there was the same
material in large pieces, in a higher . heap, still
unburnt. The same thing applied exactly in coal
heap fires—stacks of shale on the surface where tubes
were put in to ventilate the heaps. They took the
temperatures and had a very good indication of what
was going on. Experience had proved that round coal
heaps might be of a certain height without igniting,
but small coal heaps of exactly the same coal must be
exactly 4 ft. less in height, otherwise they would take
fire. The cumulative effect of the heating to which
reference was made in the paper was also borne out
by the record of the thermometer readings which were
taken from various positions in the heaps. They had
tubes, over 20 ft. or thereabout, placed right through
the heap, and the readings of the temperatures in
those tubes were extremely interesting. The warning
they had was this: one might go on reading them
every day, and find probably about 70 degs. Fahr.
That was all right. Then one might get a rise of 1 deg.
per day, which was a warning to look out. Suddenly
the increment in the temperature became 5 degs. per
day; next a sudden rise of 10 degs. per day, and so on,
rising in an upward curve, until when it reached
120 degs. one might depend upon it that by the time
the coal was cleared out and the heart of the heap
was penetrated, red-hot coal and flames would be
found. The increase in temperature was tremendously
rapid after 120 degs. Fahr, was reached. A very
interesting case of underground fire had occurred five
or six years ago on the roadside of a main haulage
road, which had been in use for 25 years. He could
not understand why, after that period of good
behaviour, that roadside should have taken fire, but
on going on the ground he found that the road W’as
driven in solid coal, with pillars of coal on the road-
side to support the roof. It was a hard, splinty coal,
and the gradually increasing pressure as years went
on had apparently crushed the coal, although it was
somewhat difficult to see any cracks with the naked
eye. To counter the fire, they built stoppings in the
side roads abutting on to the haulage way, consisting
of two brickwork walls, plastered on the outsides with
pure cement, and filled between with sand. Then they
put a pipe through the stoppings, and poured large
quantities of sand and water in between the stoppings.
A very curious thing was that 20, 30, and 40 yds. away
from the place where they were putting in sand and
water they found water oozing out from the solid coal
through fine little hair cracks which one could hardly
see with the naked eye. It appeared that the hard
splinty coal had been cracked and divided by those fine
little air cracks, until it became a veritable air sponge.
The air was permeating through the solid coal in all
directions, which was proved by the fact that water
came oozing out a long way from the place where they
poured it in ; and he thought also that the fact that
the water left the sand behind it indicated the fineness
of the cracks. Those cracks were completely filled up
with sand, and all the spaces which were formerly used
by the air for the purpose of oxidising the coal were
now occupied by sand. That had occurred five or six
years ago, and it was extremely interesting to have
the theoretical confirmation of his difficulty in Dr.
Haldane’s paper. Then, as to gob-fires, he was aware
of the advice contained in the paper that if one could
take all the coal out of the waste—the gob—and stow
the gob full of non-inflammable stone, they would pro-
bably be able to work without fires. But it was usually
in seams where that was quite impossible that fires
occurred. They had fires in seams which had three or
four layers of coal varying in quality ; the roof was
coal, the pavement was coal, and when they ripped
the roads it was a coal ripping. All the ripping was
put into the tubs and went to the pit-head as coal.
Where, therefore, were they to find anything to stow
the waste with? If the waste were stowed at all, it
must be done with inferior coal. Those were the seams
in which fires occurred with the greatest frequency,
and which had hitherto entirely baffled all their
attempts to cope with the situation. There were large