232

THE COLLIERY GUARDIAN.

August 2, 1918.

should be put up, one always came up against one
department, and that one department took care to
refer those who wanted to do the work to another
department. It was really very largely a matter of
jealousy between different departments which made
the difficulties. He thought that Mr. Evans was very
conservative in putting his yield of tar at 15 gallons,
because an average coal containing about 26 per cent,
of volatile matter would give at least 20 tons of tar,
provided the plant was working properly, whilst in
certain cannels he had obtained as much as 80 gallons
of tar, although only a portion of it could be used
for fuel oil. About 30 of the 80 gallons could be
got as suitable for fuel oil for the Navy, and there
would be up to 10 per cent, spirit and small quan-
tities of oil which could be used for lubricating pur-
poses. The working out of the oils from low-tempera-
ture plant had not yet been done in sufficient detail.
Certain people claimed so much motor spirit, so much
fuel oil, and so much intermediate oil, and so much
paraffin wax; they were usually people who were
trying to float a company, and who really did not
know anything about it. He knew of cases in which
the crude tar had been called oil. They could call
it crude oil if they liked, but it did not follow that
because they were getting 60 gallons of crude oil
that they would obtain 60 gallons of oil; yet that
was what they were led to believe. It was such claims
by the low-temperature carbonisation people which
had done such an infinite amount of harm to the
possibility of the process being taken up. Reference
had been made to the Barnsley plant, which was
called low temperature; but if they wanted to obtain
benzenoid hydrocarbons, why not start at a high
temperature? Why go into it in stages? They knew
perfectly well that at the gas works they could obtain
benzenoid hydrocarbons without putting in low-
temperature plants. He should have thought that
it would give an infinite amount of trouble and quickly
block up the tops of the retorts with carbon. He
remembered some experiments in cracking these oils
in this way, but, although it was possible to get the
benzenoid hydrocarbons, the yield was very poor,
and everything was blocked up with carbon. His view
was that the Government should either try those
retorts which had been successful on a semi-commercial
scale, or else give facilities; but they did not want
to do one or the other. The point was that we
required these oils, and could obtain them. They 1
were very suitable as fuel oils for the Navy and for
Diesel and semi-Diesel engines. Therefore, even
though it was not going to pay at the present moment,
plant should be put down for obtaining these oils, and
there would also be the fuel in addition.

Mr. E. Thompson thought the subject should be
regarded from a somewhat different point of view
from that adopted by the previous speakers in regard
to the production of a domestic fuel. The great
problem at the present time was to prevent large
towns becoming covered with smoke clouds, and the
damage done by smoke was so enormous that it would
pay to charge very large sums per ton for smokeless
domestic fuel. He had been told that coke produced
from vertical retorts could be used for household pur-
poses. He tried it recently on a coal fire, but the coal
burned away and left the coke like so many pieces
of stcne.

Waste of Small Coal.

The President stated that, as Dr. Armstrong had
said, low-temperature carbonisation was approached
by most people with considerable prejudice, and he
pleaded guilty to that himself. As an old coke maker,
in the days of the beehive oven, he had more than
once sacked a workman for producing too big a quan-
tity of black ends in his oven, and therefore they
could not expect him to look kindly on the same
substance when it went by the name of “ coalite.”
These old prejudices were really difficult to overcome.
The question of the smaller non-caking coal had been
referred to. In addition to the small that was brought
out of the % mine, there was an immense amount of
small coal left behind. He had seen places where
they loaded up their coal with in. forks and left
everything less than 1J in. in the mine; and in South
Wales, where Mr. Evans! came from, they were
perhaps the greatest sinners in that respect. He had
seen men load up all the round coal and pitch every-
thing else which gave any trouble back into the goaf.
In this way we were wasting an enormous quantity
of exceedingly valuable coal. The authorities were
afraid of the coal miners’ union, and dare not tell
the coal miner that he had got to load up every-
thing that was underground. The result was that
millions of tons of valuable fuel were left underground
and lost to the nation. This material would be ex-
ceedingly well adapted to low-temperature processes.
With regard to subsidence affecting plant erected in
the proper place, whenever a coal mine was laid out
a large pillar was left unwrought round about the
shafts, and all the plant and machinery and buildings
that were required for working the colliery were
erected on that pillar, which was large enough to
prevent any risk of surface damage affecting it. He
could hardly conceive any rational engineer putting
his coke ovens anywhere else than within the area
protected in this way, and any structure of that kind
supported on that sfiaft pillar was absolutely safe.

Mr. Evans, replying to the discussion, said that the
bulk and friable character of the low-temperature coke
was the crux of the whole question. Knowledge of
the constitution of coal was at the root of the whole
subject. What was being attempted now was to
standardise the product that entered the retort. If
coal was carbonised in a tube at a low temperature,
a structure was obtained which showed a central hole
in a series of rings, fairly closely compressed at the
outside, gradually increasing towards the centre, and
ending in a hole there. By suitable preliminary treat-
ment it was possible to get a structure which was a solid
block right through the mass, without any porous
centre whatever, and when our knowledge of the con-
stitution of coal became greater, it would be possible

to obtain that condition with practically every type
of coal. One speaker had referred to motor spirit and
the fact that it became gelatinous after standing.
That was a problem for the oil chemists, and the treat-
ment of these low-temperature tars was one that
required very careful research indeed. With regard
to the more recent developments mentioned by
Dr. Perkin, he quite agreed that the Pringle-Richards
and the Tarless Fuel Company’s processes gave good
results. In many respects the fuel was non-friable,
and the only point was whether these processes would
work on a large scale. He was very interested to find
the way in which the Government had treated the
various speakers. The Government scheme of research
was an excellent one on paper. The men in charge
of it could not be improved upon; they were the men
who would carry the scheme to a successful conclusion
if anyone could, but he was very much afraid of the
Government Department. To be a servant of the
Government was in many cases an excellent cure for
insomnia, and he would very much like to see some
method of putting a little life into some of these
Government departments and get them to work to-
gether without jealousy. With regard to the presi-
dent’s remarks concerning the shaft pillar, he was
rather thinking of existing conditions at his own
collieries, where practically the whole shaft pillar was
occupied by buildings. There was very little room
left on the pillar for a low-temperature plant, and
he had no doubt that some of the older collieries in
the country were in this position. In newer collieries
the position would be different, but possibly if a system
of hydraulic stowing were introduced, the danger of
subsidence would be reduced to an absolute minimum.

GEOLOGY OF THE SOUTH STAFFORD.
SHIRE COAL FIELD.

By J. Fox.

The rocks underlying the coal seams of the Cannock
Chase coal fields—and not only the Cannock Chase
portions, but practically all the South Staffordshire
coal fields—are supposed to have been underlain by
silurian limestone.

Considerable doubt was cast upon this hypothesis so
far as regards the northern or Fair Oak portion of
the coal field, by the work and papers of the late
Mr. M. G. Cockin, of Rugeley, and the present author
will try to substantiate his reasonings, with more
particular relation to the conditions existing in the
various parts of the South Staffordshire coal fields.

Beginning at the southern end, the conditions leave
no doubt about the existence of silurian measures at
the floor of the coal seams in that particular part
of the field. But if we travel southwards, towards
Bentley and Bloxwich, on the western side of the coal
field, and on towards Stubers Green and Aldridge
on the eastern side of the coal field, what evidence
is found, beyond that point, to prove that the silurian
rocks are still the floor of the coal seams, and what
effects have the large downthrows that cut the
northern or Cannock Chase portion of the coal field
practically in two (in a line running somewhat in
a northern and southern direction) on the rocks
underlying the coal seams beyond the places men-
tioned ? The only item of evidence we have concerning
silurian rocks existing immediately under the coal
seams is in the trial shaft of the Cannock Chase
Colliery Company, and this may be only a doubtful
proof of what is probably supposition.

If, starting some distance below the Deep coal, we
try to co-relate closely the section of the No. 2 shaft
of Cannock Chase, and the Fair Oak shaft of the
northern part of the coal field, a very great similarity
of the rocks in the two cases will be found. There
is no doubt at all but that Mr. Cockin proved that
the rocks found at the Fair Oak trial shaft are those
of the carboniferous limestone, and not of silurian
origin. Again, if the rocks found in the Cannock
Chase trial shaft are silurian, it is no proof that the
rocks found at Fair Oak are not carboniferous ; neither
/does it prove that carboniferous limestone does not
—which it most probably does — underlie all the
northern portions of the Cannock Chase coal field;
and if the rocks found at the Fair Oak shaft are
carboniferous limestone, that in itself is not much
proof of the non-existence of coal at a certain depth
all round the vicinity of the Fair Oak trial shaft.

Coal has been worked on three sides of this area
at what may be termed close distances. There are
several circumstances which appear to have been lost
sight of in relation to this trial enterprise, and which
might have completely altered the decisions arrived
at if they had been given due consideration, viz.,
the position of the trial shaft in relation to other
adjacent coal-bearing shafts and the direction and
dimensions of faults.

Another point of importance is: Have the coal
measures of the Fair Oak district suffered such an
amount of denudation as to wash away all the coal
measures down to the carboniferous limestone in this
area, or did any denudation take place at all in this
particular situation and period?

From data and facts obtained, and other geological
observations in this district, everything points to the
theory that no large (if any) denudation took place
at the particular period in question. The facts and
circumstances, as they appear to-day, in the near
vicinity of such supposed denudation could not have
remained so had the denudations been so extensive
as has been supposed by various authorities. Thus,
a little towards the south-west of this trial shaft which
is supposed to have proved the denudation, it is found
that the Deep, Shallow, and Bass coal seams are in
their usual order, and comparatively close to the
surface, the Deep seam lying not more than 140 yards
from the surface; whilst a little further away in the
same direction we get into proved ground, and find
not only the Deep, Shallow, and Bass seams, but also,
on the top of these the Yard coal and four other
seams of workable coal. If the assumed denudation

had taken place and destroyed all the seams and rocks
down to the carboniferous limestone at the Fair Oak
trial shaft, how did the Deep, Shallow, and Bass seams,
so near by, and at the same time so near the surface,
remain intact?

' The present evidence, both from the trial shaft and
the geological indications, goes to prove that if a
denudation did take place at that time it could only
have been on a small scale, and could not have denuded
any seams of coal except some that existed a few yards
under the surface.

But, in some period since that supposed denudation,
there is ample proof of a denudation which washed
away the seams that should have overlain the Deep,
Shallow, and Bass seams of the Fair Oak drawing
shaft. This can be proved from indications, sections,
etc. If the Fair Oak trial shaft had been sunk else-
where than at its present site, the carboniferous lime-
stone would not have been found till at least the best
seams of the Cannock Chase coal field had been
traversed intact and at easy working depths.

The appended data show the various strata at the
Brindley Heath, Fair Oak drawing and trial, and
Brereton shafts.

Brindley Heath Shaft.

Yards.

0-92.—Red measures.

116.	—Five feet.

122.—Eight feet.

167.—Park.

218.—Hatherton Main.

220.	—Sea level.

259.—Yard coal.

284.—Bass.

303.—Top Shallow.

321.—Shallow.

327.	—Deep coal.

346.—Deep coal.

Fair Oak Drawing Shaft.

(2,200 yards from Brindley Heath Shaft.)
Yards.

0-40.—Red measures.

47.—Blue binds.

53.—Rock binds.

77.	—Bass coal, 7 ft. 10 in.

92.—New Shallows, 5 ft. 6 in.

104.—Shallow coal, 9 ft.

117.	—Deep coal, 3 ft. 2 in.

122.	—Deep coal, 3 ft. 10 in.

131.—Rock and shale.

200.—Sea level.

Fair Oak Trial Shaft.

(900 yards from Fair Oak Drawing Shaft.)
Yards.

0-180.—Red measures.

20.—Variegated sandstone.

30.—Consolidated clunch.

40.—Yellow pebbly sandstone.

55.—Cons, sand with lead.

60.—Grey sandstone.

100.—White marl.

110.—Red marl and ironstone balls.

141.—Smutty coal.

150.—Variegated sandstone.

160.	—Red and white rock.

163.—Purple marl.

171.—Blue binds and ironstone balls.

180.—Sea level.

180.—Dark blue binds.

192.—Coal 1| in.

200.—Stone binds.

221.	—Fireclay. (Fault here rising towards the

north-west.)

231.—Binds.

240.—Fireclay.

255.—Peldon.

266.—Strong binds and ironstones.

273.—Bottom of shaft.

[273-328.—Borehole. ]

280.—Grey stone binds.

284.—Red sandstone.

290.—Dark binds.

305.—Red variegated rock.

320.—Red and grey rock.

328.	—Red rock, marl partings and salt water.

Brereton Shaft.

(Distance from Fair Oak Trial Shaft not taken.) •
Yards.

0-33.—Red Measures.

35.—Four feet seam.

45.—Two feet	,,

57.—Two feet	,,

60.—Three feet ,,

76.—Four feet	,,

78.	—Nine feet	,,

95.—Four feet or Bass seam.

123.	—Top Shallow.

133.—Sea Level.

140.—Shallow coal.

158.—Deep	,,

161.	—Deep	,,

175.—Two feet seam.

215.t—Mealy grey, 4 ft. thick.

Coal Production of the Ukraine.—The greatest coal
mining region of Russia is situated on the Donetz River,
north of the Sea of Azof. In 1914 the coal output had
risen to 22,932,700 tons per annum. The iron ore of
the district contains up to 40 per cent, of metallic iron,
and the largest works were founded with English capital
at Jusow. The richest iron ore mines are near Krivoi-Rog,
in the watershed of the Ingulez, the southern branch of
the Dnieper. This ore contains up to 60 per cent, of
metallic iron. In the year 1912 the production of iron
ore from all the mines in both European and Asiatic
Russia was 6,363,166 tons.