123

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THE COLLIERY GUARDIAN.

January 15, 1915.

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Auxiliary Plant.

The exhausters, as indeed the whole of the auxiliary
plant, are installed in duplicate. The exhausters are of
steam-driven type running at 70 revolutions per minute
and each capable of dealing with 265,000 cubic feet of
gas per hour. The exhauster house, like the rest of the
buildings, has a tiled floor, painted walls and a wrought
iron roof underdrawn with varnished pitch pine, whilst
it is lofty and well lighted.

The gases next pass through a Pelouze and Andouin
tar extractor capable of dealing with the whole volume
of gas. Thence the gas passes in succession through
three ammonia scrubbers, a gas dryer, three benzol
scrubbers (each 50 ft. high), from these to a further
dryer, and thence back to the ovens through a Parkinson
and Cowan regulator at a constant pressure of 150 mm.
The surplus gas, which amounts to between 50 and 55
per cent, of the total gas evolved from the coal, serves
to raise steam under four Lancashire boilers, and will
be eventually used to fire a further four similar boilers
at the colliery, when the whole of the ovens are put in
service.

The scrubbers are carried upon a platform above the
apparatus gallery, and the whole of the plant is thus
easily accessible for inspection, all pipes being above
ground. All the pumps for the scrubbers, etc., are
housed in the apparatus gallery. They are of the
Eureka steam - driven type. The arrangement is
certainly unique, but it is such that the whole of the
plant can be attended to by one man. At the end and
rear of the scrubbers are three storage tanks, each of
30,000 gallons capacity ; of these, one serves for
condensate, and two for ammonia liquor. A fourth
tank for the storage of tar has a capacity of 40,000
gallons, and from this the tar gravitates to the loading
siding.

The strong ammonical liquor is pumped from the
storage tanks to the sulphate factory, where it is treated
with steam and milk of lime in a Coppee ammoniacal
liquor still. Two of these stills are provided, of which
one acts as a stand-by. The ammonia thus driven off
is delivered into one of the two enclosed-type separators,
where, in combination with sulphuric acid, sulphate of
ammonia is formed. The salt is ejected from the
saturators by steam ejectors on to a draining table,
from which the mother liquid is run back into the
saturator. The wet salt is then delivered into one of
the two centrifugal dryers, from which the dry salt
passes to an eledricaily-driven sulphate conveyor, by

Fig. 2.—Section through Side Wall
of Ovens.

B

which it is distributed in the sulphate store which
adjoins. The walls of the stores are lined for the first
12 ft. of their height with acid-proof asphalte.

Benzol Plant.

The benzol plant is arranged for the production of
crude and rectified benzol, and is housed in a separate
building in which special means have been provided to
secure adequate ventilation and to minimise risk of fire.
The benzolised oil from the scrubbers receives a
preliminary heating in a series of heat exchangers, in
which it absorbs the heat given up by the debenzolised
oil returned from the still. The benzolised oil, after
further heating in steam-jacketed heaters, is passed
into a Coppee benzol still in which the action of steam
drives the benzol from the oil. From this still the
crude vapours are passed into a dephlegmating still, in
which a certain portion of the naphthalene and heavy
oil condenses. The partly purified vapours are next
passed into a fractionating condenser capable of very
delicate adjustment. The vapours which condense in
this apparatus form the crude benzol, which is passed
to the rectification plant. Here it is successively
washed with strong sulphuric acid and caustic soda in
a washing tank, which remove basic and acid impurities
respectively.

After a final washing with water it is passed into the
fractionating still and redistilled. The first fraction
forms the 90 per cent, benzol, the latter fractions
being the 50 per cent, benzol and solvent naphtha
respectively.

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Shipments of Bunker Coals.—During the completed year
ended December 31 the quantity of coal, etc., shipped for the
use of steamers engaged in the foreign trade amounted to
18,535,579 tons, as compared with 21,031,550 tons in 1913,
and 18,291,370 tons in 1912. The quantity so shipped in
December was 1,248,215 tons, as against 1,842,006 tons in
December 1913, and 1,556,784 in December 1912. .

Hull Coal Exports.—The official return of the exports of
coal from Hull to foreign countries for the week ending
Tuesday, January 5, 1915, is as follows :—Amsterdam, 192
tons; Aalborg, 1,943; Alexandria, 3,264; Christiania, 1,735;
Duclair, 2,146; Dunkirk, 298; Gothenburg, 293; Harlingen,
780; Helsingborg, 1,224; Hobro, 1,388; Kalmar, 1,668;
Malmo, 1,946; Marseilles, 5,511; Rotterdam, 1,051; Rouen,
25,490; Stockholm, 852; Trondhjem, 251—total, 50,032 tons.
The above figures do not include bunker coal, shipments for
the British Admiralty, nor the Allies Governments. Corre-
sponding period January 1914, total 59,515 tons.

MINING EDUCATION IN 1913-14.

The report on the second year’s proceedings of the
Board for Mining Examinations was presented on
October 14, 1914, and is included in Part II. of the
General Report on Mines and Quarries for 1913.

The following changes have occurred in the staff of
examiners:—'Messrs. W. B. Wilson and P. L. Wood
were appointed to fill the vacancies among the central
examiners caused by the resignation of Messrs. J. H.
Merivale and J. Dean; Mr. J. W. Ainsworth was
appointed an alternative central examiner vice Mr. G. J.
Binns, resigned. The names of the central examiners
at present are as follow:—Mr. James Hamilton, Mr.
W. B. Wilson, Mr. A. M. Henshaw, Mr. P. L. Wood,
Dr. W. Galloway, Mr. H. M. Morgans (with two
alternates), Mr. J. W. Ainsworth, Mr. R. S. Williamson.

The names of those composing the panel of local
examiners remain the same as last year with one
exception, Mr. T. G. Lees having been appointed in the
place of Mr. W. B. M. Jackson, resigned.

The half-yearly examinations were held, as usual,
during t! e last week of November 1913 and of May
1914, and extended over three days at most of the
centres at the first, but only two days at all of the
centres at the latter examinations. The numbers of
applicants who presented themselves for examination
were as follow:—

Per-
centage
of passes.
.	37*2

.	3P5

.	46*6

•	First-class certificates ... 242	...	90

Second-class certificates ...	518	...	163

Surveyors'’ certificates ... 204	...	95

The order of merit in point of percentage of passes
of the different centres was as follows :—■

First-class. Second-class. Surveyors.
Sheffield ....... 50’7 (30’0)*.. 31*0 (2P0) ... 44T (22 2)
Newcastle ..... 33’3	(32’5)	...	33 3	(38’7)	...	50’0	(16*7)

Wigan ......... 32-4	(23’9)	...	32'5	(30’6)	...	50’0	(21’4)

Cardiff.........	31’8	(23 7)	..	22’6	(24’7)	...	39’3	(8’3)

Edinburgh.....	30’4	(11’7)	...	33’6	(39’8)	...	47’6	(40’0)

Birmingham...	25’0	(33’3)	...	42’5	(34’7)	...	60’9	(16’7)

* The figures in brackets are the percentage of passes for
the two examinations held by the Board in the period
1912-13.

Fig. 3.—Diagram of Gas and
Air Passages.

Fig. 4.—Sectional Plan through Regenerators and
Collecting Flues.

It will be seen that, as compared with the examinations
held during 1912-13, there was a much higher percentage
of passes in respect of the first-class candidates at all
the centres except Birmingham, where the percentage
fell from 33'3 to 25. As regards the second-class
candidates, only at three of the centres was there a
higher percentage of passes ; in each of the other three
it was lower. The percentage of candidates who passed
for the surveyors’ certificate was much higher at all the
centres.

The Board asked the central examiners to report
fully in respect of each centre and subject of examina-
tion on the results and inferences to be drawn from the
last examination—viz., that held on May 26 and 27—a
course it is proposed to follow in each of the future
examinations. They have submitted tables giving for
the May examinations the comparative results as
between the various centres in respect of the three
classes of candidates—viz., first-class, second-class, and
mine surveyors. Their results show the number of
candidates, number of passes, percentage of passes and
average marking in each subject.

Sir Richard Redmayne, chairman of the Board,
epitomises the results of the reports of the six
examiners:—

Mr. Hamilton states that “ The local examiners who
conducted the viva voce examination express the view
that the candidates as a whole showed some improve-
ment compared with former examinations under the
Coal Mines Act of 1911. The improvement appears
progressive, though the rate of advance is slow. The
candidates generally seemed to find it difficult to think
independently. They appeared to rely too much on
what they had been taught, and too little on their own
experience and observation. This was shown by a
certain difficulty in grasping the mining conditions
with which they should have been familiar when put
before them in examination, and a consequent failure to
adequately meet these conditions in their answers.
The candidates for surveyors’certificates did better in
their written work than could have been anticipated
from their viva voce examination. Dealing in particular
with the written examination in Subject 5 (Surveying
and Drawing), there is considerable improvement to
record, though how much is due to advance in the
candidates’ attainments, and bow much to inevitable
variations in the papers, is difficult to say. There was,
as usual, a marked tendency to use formulae even in
purely arithmetical calculations, where formulae should

be unnecessary, and should, strictly, not be allowable-
These formulae are often imperfectly understood or
imperfectly memorised, and the results are often
fantastic. A striking feature brought out by these
tables is that in both first and second class the average
percentage is markedly lower in subjects 2 and 5
(Ventilation and Surveying), and most markedly in the
latter, than in the other subjects in nearly every
district. Probably this is accounted for by the baleful
influence of formulae, which play a larger part in these
subjects than in the others. In the case of surveying
and arithmetic the poor results are probably partly due
to these being looked upon as subjects of minor
importance, and to arithmetic being a subject everyone
is supposed to know without special preparation.”

Mr. Wilson reports:—“ One would gather, from the
stereotyped wording of the answers to many of the
questions, that coaches play a very prominent part in
the preparation, more especially of the second-class
candidates. This is probably more noticeable in subject
No. 6 than in other subjects. The assistance of these
numerous coaches is now very generally accepted, and
doubtless in many cases they perform a useful duty,
but I fear the result is becoming the production of a
very superficial article, rather than a class of sound
pitmen. In the recent examination I had the same
question, ‘ as to the treatment of safety lamps,’ in both
first and second-class papers. Being a fundamental
subject, in which all candidates must be thoroughly
acquainted, it has generally appeared in some form, but
the question has hitherto appeared in the second-class
papers only, the result being in this examination that
the answers of the second-class candidates to this
question were better and fuller than those of the first-
class men. I take this to be, to some extent, the effect
of coaching. The system of ihe examination is good.
There is perfect uniformity in the written examination
—the same gauge is applied to the man in Edinburgh
and the man in Cardiff—but this is scarcely so in the
viva, voce examination. There is a lack of assurance of
uniformity in this branch of the examination.”

Mr. Henshaw reports that the Sheffield centre as a
whole showed very satisfactory results, giving the
highest percentage of qualifications in the first class,

and, with the exception of Birmingham, in the second
class also. He remarks in respect with the subjects
with which he was most particularly concerned—viz.,
explosions, spontaneous combustion and rescue work—
that whereas in the earlier examinations the work of the
candidates was very unsaiisfactory—due, he thought, to
lack of tuition and suitable lectures—the results in May
last were very good, comparing well with those of any
other subject.

Mr. Wood reports that in respect of the examination
for second-class certificates, the written portion of the
examination was good as compared with that of the
previous (November) examination. In the Wigan centre
the greatest improvement is that in subject No. 3
(Explosions, &c.). but Mr. Wood is more especially
concerned with No. 1 subject (mining and working),
and he considers that in respect of the work of candidates
in this subject “there is more weakness shown in the
sketches than in anything else, and this applies to both
first and second class candidates.”

Prof. Galloway is most concerned in the theory and
practice of ventilation. He considers that, as a whole,
there was “ a well-marked improvement in the attain-
ments of the candidates. There were, as heretofore, a
few very good candidates, a few very inferior, and a
large number ranging in merit from good to inferior.
The number of very illiterate candidates has decreased ;
but amongst those who could neither spell nor write in
a passable manner there were several who gave intelli-
gent and correct answers to most of the questions, a,nd
obtained a high average of marks. Most of the
candidates were able to solve correctly those numerical
questions which involved a slight knowledge of how to
manipulate algebraical equations. In this respect I am
glad to be able to report a great improvement, even
amongst those whose writing and grammar would not
have led me to expect such a result. On the other hand,
most were very weak in sketching mining appliances by
hand ; in fact, I may say that I consider this to be their
weakest point.” Prof. Galloway thinks “ it is of great
importance that a colliery manager should be able to
sketch as well as to write legibly, so that he may be in a
position to convey his thoughts intelligently to those
whose duty it is to carry out his instructions. These
remarks apply to candidates for both first and second
class certificates ; some of the latter class were, however,
much more intelligent than many of the former. Taken
as a whole the Sheffield candidates were better than
those of any of the other centres; those of Birmingham