986

THE COLLIERY GUARDIAN.

Novembeb 6, 1914.

COAL MINING PRACTICE IN ILLINOIS.

The Illinois Geological Survey has recently conducted
an investigation into the methods pursued in the various
districts. Some interesting details are given in the
report on the No. 2 or Jackson county district, made by
Mr. S. C. Andros. This is an isolated coalfield which
produces about half-a-million tons per annum, but
95'9 per cent, of the output is got by machine, and all
the mines are worked from shafts.

Bed two has only a shallow cover, the coal lying at
depths varying from 25 to 160 feet at different mine
locations. A characteristic feature of the bed is its
division into two benches by a grey laminated shale
band varying in thickness from | in. to 36 ft. The
bottom bench varies in thickness from to 4 feet,
averaging 3| ft. The top bench averages 2 ft. . The bed
contains few nodular concretions of iron pyrites, but has
a layer of bone 2 to 3 inches thick, generally next to
the floor. This floor in most places is sandstone, but in
sections is shale or fireclay. The coal shows a pro-
nounced cleavage, north-east to south-west. Where the
parting is thin and the two benches are united, the roof
over the coal is a hard grey shale, but where the
parting is thick and only the lower bench is worked, the
parting becomes the roof. Where this parting is a light
grey shale it is easy to support; where it is dark
coloured, it slakes much on exposure to the air. The
presence in places of a quicksand deposit about 30 ft.
below the surface has a marked effect on surface
subsidence after roof caves.

The face samples of coal from this district when
ground to 200-mesh size, air dried and tested in the
explosibility apparatus at the Urbana laboratory, show
less explosibility than the coal of any other district in
the State, although the rib dust of some other districts
is less explosible on account of an admixture of fine
shale dust. A table is given comparing pressures
developed in the explosibility apparatus for the various
districts in Illinois. From this it appears that the
Jackson coal developed pressures at 2,192 degs. Fahr, of
5’88 lb. per square inch, whereas the coal from six of the
other seven districts of Illinois developed pressures
ranging from 71b. to 8’93 lb. per square inch.

Where both benches are worked and the bed is over
6 ft. thick, only the lower 6 ft. of coal is mined, 8 to 12
inches of top coal being left. The shale roof disin-

L

Fig. 1.

tegrates on exposure to the air, but top coal is not
affected by temperature and remains intact for many
years. Where it is possible to leave top coal in entries
the roof is arched. All arching in the upper 3 ft. is
hand-sheared, with the result that the top coal remains
permanently in place and requires no support except
where fractured by slips. Where the two benches of
the bed are united but the coal is not over 6 ft. thick,
the full thickness of the bed is mined, and the grey
shale overlying the coal becomes the roof. W here the
lower bench only is worked the miner brushes over
14in. of roof over roadways in rooms. The width of
brushing varies from 5 to 8 feet. The proportion of
coal won varies from 44 to 55 per cent.

When the lower bench only is mined the roof is
supported by three-piece timber sets having 8 in. cross-
bars and 6 in. legs. White oak is generally used for
entry timbering. In a few instances the legs of the
timber set are placed in hitches cut in the ribs (fig. 1).
In one mine 8 lb. steel cross-bai s with T section are used
on white oak legs under bad roof on main haulage entry
and white oak cross-bars in all other entries. Propping
expense is heavy; the number of props per 100 square
feet of roofing varying fro-u 4’8 to 7’5 is greater than
in any other district in Illinois. Room propping is
carefully done in the district, especially in one mine,
where systematic propping is enforced. At this mine,
where pillars are drawn by cutting a slab 6 ft. wide from
each rib, two extra rows of props are set between the
track and the right-hand rib to support the roof as the
pillar is drawn. The following table shows the cost of
timber at four mines examined :—

Room props.

.s

& o
cr o

• OD *“•
£8 ©

5 o

‘-4-5 Cf O Cg

Cg

O co

A °

tr1 o

. O

OT CC £-1
O

O °

12 ...	..	8	...	...	6’6	..	.... 26’4 ...	... 4
13 ...	—	...	4’8	..	.... 33’6 ...	... 7
14 ...	—	..	7’5	..	.... 33’8 ...	... 4*
15 ...	--	5’5	... 38’5 ...	... 7

At three of the four mines examined puncher
machines operated by compressed air are used; in the
other mine the coal is undercut with electric chain
machines. The usual method of supplying air to the
puncher machines is to carry it from the compressor
down the shaft and through the main entry in a 4 in.
pipe, reducing to a 2 in. in the cross entries, and to
Ilin, from the cross entries to the faces of the rooms.

HYDRAULIC STOWING.

Lecture at Stoke Mining School.

A lecture on hydraulic stowing and its suggested applica-
tion to Staffordshire collieries was given by Mr. J. Drum-
mond Paton, of Manchester, at the Mining School, Stoke-
on-Trent, on Saturday. Mr. E. B. Wain presided over a
large attendance. Mr. Paton’s lecture, which was illus-
trated by photographic slides and diagrams, amplified a
paper read by him before the Manchester Geological and
Mining Society on May 12 last.

The question of obtaining material, said Mr. Paton, was
an important one. In the Staffordshire district they had
heaps of mine refuse available for the purpose, though it
was marvellous how quickly the colliery heap would dis-
appear when the material was used for hydraulic stowing.
For the purpose of obtaining material from centres where it
was available, he contended that arrangements could be
made with the railway companies for cheap transit rates.
Wagons were sent out loaded with coal, and returned
empty. Instead of that, they might be returned, by way
of a centre, where stowing material was available, and
brought back loaded with that material. The lecturer
explained the types of pipes in use for the conveyance of
the material, and dealt with the general advantages of the
system.

In the course of discussion that followed, the Chairman
said in that district they saw the effects of mine working
on valuable buildings, and also huge and growing heaps of
mine debris. If those heaps could be used for supporting
the mines in a thorough way, it would be a great advantage.
When Mr. Paton said that the subsidence in a stowed mine
was only 2 per cent., and when they remembered that the
average subsidence in an ordinary hand-packed mine w7as
something like 50 per cent., they realised how very much
it would be to the advantage of the country at large if such
a system could be generally adopted. It had been largely
used in Germany. Three or four years ago, when he was
there, he was told that something like 100 miles of railway
were being built specially to convey stowing material to
some of the Westphalian collieries. If their great com-
petitors were adopting it successfully, it was essential that
they should look into it and see if it were adaptable to Eng-
lish conditions. In their district he thought there was some
opportunity for adopting the system.

Mr. W. G. Peasegood, referring to the western side of
the North Staffordshire coalfield, said he was interested to
hear of this method of stowing by means of refuse from the
surface, but he would rather stow the seams he had to
work with explosive gas; in fack, he could only work them
in descending order. He could not see his way to stowing
them with refuse from the surface. For 25 years they had
worked seams subject to spontaneous combustion — the
Bough Seven Feet, the Seven Feet Banbury, and the Bull-
hurst—without difficulty, charging the goaf wTith gas and
keeping oxygen away. Oxygen supported combustion, and
if they kept air from the goaf they would have no fire. With
thick seams of 12 ft. or 14 ft. he did not see that they could
work them on the longwall principle. Even if they could
adopt this hydraulic stowing system, what would be the
cost? If they worked a colliery, they had got to work it
at a profit.

Mr. A. M. Henshaw said he had seen hydraulic stowing
in Germany and France, and he believed they were doing
it better in France than Germany. (Applause.) The
hydraulic stowing he saw underground in one of the Pas-de-
Calais coalfields was as near perfect as hydraulic stowing
could be. The system had many advantages where the
geological formation was favourable, where the seams were
of ordinary gradient and fairly free from faults, where the
colliery was a fairly new one, and where the company had
plenty of money. (Laughter.) But in North Stafford-
shire the difficulty w7as to apply a new system like that to
the difficult conditions of their collieries, and to collieries
which wrere in their middle age, if not in their “ sere and
yellow leaf.” Moreover, although they had thick seamg
and seams subject to gob-fires, their great trouble, at any
rate in that part of the field where gob-fires occurred, was
the extremely faulty and Undulating character of the strata.
In giving evidence before the committee investigating spon-
taneous combustion in mines, he had illustrated local condi-
tions by a section of an actual colliery, and had asked if
hydraulic stowing were applicable to a colliery like that. It
was admitted that although possible from the engineering
point of view, it was impossible from the commercial. They
worked their collieries, Mr. Henshaw added, not as engi-
neering projects, but as commercial undertakings.

Mr. J. R. L. Allott was afraid the system would prove
very costly. The question, however, was a very important
one, and if something could be done to prevent gob-fires, it
would be a great advantage. He had to work seams liable
to gob-fires, and the only system they could adopt was work-
ing from tlw rise downwards, and allowing the goaf above
to fill with gas. That probably seemed awful to people not
accustomed to it, but it was the only system they could
adopt in working the rearer seams.

Mr. W. Barber, who also spoke with considerable experi-
ence of working rearer seams, referred to the difficulties of
applying hydraulic stowage to those seams. Moreover, the
cost appeared likely to be prohibitive.

Mr. J. T. Stobbs (principal of the Mining School) said he
was sure that the system of hydraulic stowing would be
tried some day in North Staffordshire. In North Stafford-
shire they had thick seams that were being left in. because
of gob-fires; they had coal left in, because it was overlaid
by drowned out workings: and they also had coal left in
because of valuable property above. These were cases
where hydraulic stowing alone held the field for the getting
of the coal, and it was unthinkable that that coal should bo
left for ever in the earth. Coal was too valuable to leave,
and, so far as he knew, hydraulic stowing was the only
means which would enable them, in the particular circum-

stances he had indicated, to get the coal without running
risks which would be hardly permitted to-day. They were
greatly obliged to Mr. Baton for his lecture, which was the
beginning of an enquiry into this system.

A hearty vote of thanks was accorded to Mr. Paton for
his lecture.

COAL, IRON AND ENGINEERING COMPANIES.
REPORTS AND DIVIDENDS.

Algoma Steel Corporation Limited.—An informal meeting
of the holders of the 5 per cent, first and refunding mort-
gage bonds and the three-year gold notes of the Algoma
Steel Corporation Limited will be held at Winchester House,
Old Broad-street, E.C., on November 9th, to consider a
proposal for the funding of two years’ interest on the bonds
and notes and for other purposes.

Broomhill Collieries Limited. — The 14th annual report
states that the profit for the year amounts to £47,371 10s. 6d.
—to which has to be added balance brought forward,
£20,133 6s. Id.—making £67,504 16s. 7d. Out of this sum
the following have been paid : Interest on debenture stock
for the year, <£5,722 2s. 9d.; preference dividends for one
and a-half years to December 31, 1910, paid—July 1, 1913,
£4,943 15s.; September 30, 1913, £4,943 15s.; November 15,
1913, £4,943 15s.; sinking fund instalment, £10,111;’depre-
ciation written off, £16,700; making £47,364 7s. 9d.; balance
carried forward, £20,140 8s. lOd. The cost of the National
Insurance (Health and Unemployment) Act during the year
to the company was £1,623 5s. 8d. The rates paid for the
year were £4,783 Ils. 7d., against £4,218 9s. 2d. in 1912-

1913.	The output was 701,111 tons, against 738,809 tons in
1912-1913. The cost of the underground fires during the
year wTas £1,570 17s. 8d., against £622 19s. 2d. last year.
The liabilities have been further materially reduced as shown
in the accounts, being (exclusive of debenture stock) £22,442
5s. 5d., against £58,060 0s. 9d. at June 30, 1913.

Brown (John) and Company Limited. — Mr. Justice
Neville on Tuesday had before him a petition by Messrs.
John Brown and Company Limited, for the sanction of
the Court to an extension of their memorandum and articles
of association. The Hon. C. E. Macnaghten, K.C.,
appeared in support of the petition, and there w7as no oppo-
sition. His lordship, however, objected to sanction an
extension of the company’s objects in the very wride terms
proposed. The directors, he suggested, should consider the
matter, and put before the Court what it was they really
did want. As it at present stood, if he granted the peti-
tion the company had power to treat any subsidiary busi-
ness as their principal business, and that would enable them
to divert their capital from one object to another. Ulti-
mately it was arranged that the petition should stand over
for a fortnight, with liberty to amend if necessary.

Carlton Main Colliery Company Limited.—The directors
have declared an interim dividend of 5 per cent, on the
ordinary shares.

Cortonwood Collieries Company Limited.—The directors
have declared a further interim dividend of 2| per cent. (6d.
per share), less tax.

Metropolitan Carriage, Wagon and Finance Company
Limited.—The directors have declared the following divi-
dends for the half-year to September 30 last :—On ordinary
shares at the rate of 7| per cent, per annum, less income-tax;
on “A” preference shares, 5 per cent, per annum, less
income-tax; on “ B ” preference shares, 6 per cent, per
annum, less income-tax.

Parkgate Iron and Steel Company Limited.—The directors
have decided to pay an interim dividend of 9d. per share
(free of income-tax) for the half-year ended September 30.

Scottish Australian Mining Company Limited. — The
report by the directors for the six months to June 30, 1914,
states that the sales of coal during the half-year amounted
to 149,417 tons. Since the close of the half-year under
review the outbreak of war in Europe had caused much
dislocation of the foreign coal trade from Australia. Freights
for carriage of .coal had risen, and additional cost has been
thrown on the trade for insurance against war risk and for
telegraphic communication. The continued fall in the price
of copper has exercised a depressing influence upon the work
of the Cadia Copper Mining and Smelting Company, and
when war broke out and operations on the Metal Exchange
in this country were suspended, the cessation of work at
Cadia became unavoidable, and the mine and furnace were
closed down. The general revenue account to June 30,

1914,	shows a balance of profit amounting to £11,070 6s. lOd.
The directors propose to pay a dividend for the half-year at
the rate of 5 per cent, per annum, less income-tax, which
will require £6,250, and to carrv forward to the next account
£4,820 6s. lOd.

South Durham Steel and Iron Company Limited. — The
directors have declared a final dividend of 5 per cent., making
10 per cent, for the vear, as against 25 per cent, for 1912-
1913.

NEW COMPANIES.

Harrison (J. W.) Limited.—Private company. Regis-
tered office, 15. Vicarage-street, Wakefield. Registered
October 24. To acquire business of engineer and iron-
founder carried on by J. ’W. Harrison at Vicarage-street
Iron Works, Wakefield, as J. W. Harrison, and carry on
business as engineers, ironfounders, machinery makers, etc.
Nominal capital, £5,000 in £1 shares. Directors :—John
William Harrison. 29, Peterson-road. Wakefield, engineer;
George William Harrison, 7. Stonehaven-terrace. Stanley-
road. Wakefield, engineer. Qualification of directors, £100.

Implitico Limited.—Private company/ Registered office,
2, 4. and 6. Pocock-street, Blackfriars. London. Regis-
tered October 30. Electricians, mechanical engineers, manu-
facturers. workers, and dealers in electricity, motive power,
light, etc. Nominal capital. £3,000 in £1 shares. Govern-
ing directors and subscribers (one share each) :—W. R.
Lambert, 28. Avington-grove, Penge, S.E., electrical engi-
neer: H. S. Lambert. 203. Waller-road. New Cross. S;E.,
electrical engineer. Qualification of above directors, £500.

Jamaica Coaling Company Limited. — Private company.
Registered office. 20, Moorgate-street. E.C. Registered
October 2^. To carry on in the Island of Jamaica the busi-
ness of dealers in and merchants of coal. coke. oil. and
timber, and proprietors of docks, wharves, stores, ship-
owners. engineers, tugowners, etc. Nominal capital. £100
in £1 shares. First directors to be appointed by sub-
scribers.