280

THE COLLIERY GUARDIAN.

February 5, 1915.

the truth. No one outcrop runs for more than a few
hundred yards, and the persistence of the productive
strip is due to repetition of the crops of the same two
or three veins by. innumerable overthrusts arranged
along one general line.

The coal, which is thus brought close, to the surface in
extraordinary abundance, has been dug for some
centuries, for its working was described as an ancient
industry in 1595.

The digging, or “ smutting,” as it was called, of this
surface coal, has ceased except for a few small holes
opened by the farmers, but enormous depressions and
” reens ” (trenches), now thickly overgrown, testify to
the amount of coal raised in old days. No written
records or plans of the old workings exist, and there are
few men now living who-saw any of them in operation,
but the following descriptions will serve to explain much
of what may be seen of them among the old “ rubbish
backs ” (shale tips).

For the whole breadth of the strip thrust follows thrust
and the structure of vertical south rising, dead centre,
and north rising is repeated again and again. Further
than this there are an infinite number of small over-
thrusts or ” overlaps ” doubling and trebling the out-
crops in a few yards, throughout the ground occupied
by the “ smuttings. ” At Moreton and Wooden it is
said that there was coal everywhere within the memory
of living men. A crop would be “ smutted out,” but a
short driving rarely failed to meet another crop of the
same vein close by. The statement is confirmed by the
appearance of the ground at the present day.

Under a part of the ground where these strangely
jumbled masses of the Timber Vein occur, the Lower
Level and Kilgetty veins are now being worked at a
depth of about 150 yds. Of the innumerable folds and
thrusts observable on the surface, not one in 50 exists
at that depth; only the main folds or faults, which define
the principal belts of the coalfield, can be recognised.
In order to grasp the significance of this fact, it is
necessary to consider the general structure of the coal
basin. It is, broadly speaking, a syncline, and the strata
in the interior of every syncline must have undergone
greater compression than those in the outer curves.
Again, the syncline is asymmetrical, in consequence of
the thrusting-up of the strata in its southern limb. This
asymmetry is reflected in the form taken by the outcrops
in the strip described above. Thirdly, the thrusting was
not only northwards, but upwards, a fact shown by the
inclination of the thrust planes, and by the tendency of
older strata to override newer strata towards the north,
and it is for this reason that the planes of movement
which affect the southern limb tend to emerge at the
surface in the centre of the syncline. Lastly, the rocks
lying below the productive belts include such formations
as the lowest coal measures, the millstone grit, carboni-
ferous limestone, and old red sandstone. It is safe to
assume that these massive formations, apart from the
fact that they occupy the outer curves of the syncline,
would show deformation on a broader scale than the
soft strata associated with the Timber Vein series.

Fossils.—Mullusca are rare in the Pembrokeshire coal
measures. Carbonicola aquilina (J. de C. Sow.) occurs
abundantly in the roof of the Lower Level Vein in East
Pembrokeshire, and a lamellibranch which may be
Carbonicola is so abundant in a band below the Scad
Vein near Amroth as to form an impure limestone.
Lingula mytiloides (J. Sow.), Myalina and Anthracomya
sp. occur in the cPffs west of Monkstone not far above
what we take to be the top of the millstone grit. The
lower measures have also yielded near Picton Point
Ambocoelia cf. urei (Flem.), Chonetes laguessiana de
Kon., Ch. sp.j and Aviculopecten sp. nov.?

(To be continued.)

The Coal Resources of Spain.—In a paper read before the
Eighth Congress of Commercial Expansion at Barcelona,
Don Luis Vidal, ex-inspector-general of mines, gave the
following particulars on the coal resources of Spain :—Coal
is raised in seven provinces, viz., Oviedo, 2,373,403 tons;
Cordoba, 333,340 tons; Ciudad Beal, 333,010 tons; Leon,
310,499 tons; Sevilla, 154,250 tons; Palencia, 109,094 tons;
and Gerona, 12,070 tons—an aggregate production of
3,625,666 tons, valued at 59,520,601 pesetas (nearly 2 J
millions sterling). This quantity is very small for a
country which, according to Mallada, has an area of
10,634 sq. km. of coal bearing lands. Of this area, however,
only 39,188 hectares are being worked under mining grants,
and hence it is that Spain only ranks fifth among the coal
producing countries of Europe/ The coal measures are con-
centrated in the north and in the south-west of Spain. Nature
has not been prodigal with this material in the eastern
districts; but all varieties of coal are found in the others,
from anthracite to bituminous coals suitable for all indus-
trial purposes. It appears, therefore, certain that Spain has
sufficient coal resources of her own to dispense with a con-
siderable proportion of the fuel now imported from other’
countries, more particularly since the experience gained in
the war with the United States proved that the vessels of
the Compania Trasatlantica, burning Asturian coals, were
able to steam much faster than the fleet, which used English
coal. The reserves of unworked coal in Spain have been
estimated, by Adaro, at 9,000 million tons. Lignite is
found in many Spanish provinces, though worked in nine
only. The total annual output is about 263,000 tons, viz.,
Barcelona, 111,400 tons; Teruel, 97,800 tons; Gfuipuzcoa,
23,000 tons; Baleares, 18,400 tons; and Zaragoza, 12,300
tons.. The quality varies considerably, being found in very
different geological formations, and ranging from the
cretaceous coals of Utrillas and G-argallo — which have a
heating value of 6,000 to 6,500 calories, and bear a close
resemblance to true coal — to the miocene lignite of La
Cerdana, with a calorific power of only 3,483 calories. How-
ever, by reason of the very low heating value of most
Spanish lignites, the deposits have remained unworked
because the cost of transport has been too great to allow
the products to compete with imported coal, until the late
considerable rise in the price of English coals revived this
industry, so that some of the mines, such as the Figols
mines (Barcelona), are running full time, after dragging
out a.precarious existence for several years.

ELECTRIC v. OIL SAFETY LAMPS.

Mr. Hailwood’s Reply to his Critics.

At the meeting of the Midland Institute of Mining,
Civil and Mechanical Engineers, held at Doncaster on
January 23, Mr. E. A. Hailwood read a reply to the
criticism on his paper read at the meeting of the insti-
tute on September 29, 1914, on “ Miners’ Electric Lamps
Compared with the Combustion Tube Lamp,” and
notably to the paper read by Mr. Wm. Maurice at the
meeting held on November 27. The following is
Mr. Hailwood’s reply, which has been somewhat
condensed:—

There is no doubt that inspectors of mines did get
misled by the extravagant promises made by the electric
lamp makers, but I think, on the other hand, that they
have now come to i ecognise the limitations of the
electric lamp, and to realise that they fall far sboit cf
the original promise. Taking one point alone, viz.,
illumination, those who were in the room at the Home
Office when the application by the electric lamp makers
for a reduction in the Home Office requirement of
lj-candle power for 10 hours for the electric lamp was
being discussed, could not but notice the surprise
manifested by the Chief Inspector of Mines when fold
that the illumination of ILcandle power or 2-candle
power, said to have been given by a lamp which won the
prize, could not be maintained in practice, and that the
makers of eh ctric lamps begged for a maximum standard
of not more than 1-candle power.

The combustion tube lamp meets all the Government
requirements, and may do this and have only four
pillars when it is fitted with the writer’s patent pillar
sheath, so that Mr. Maurice’s objection to the fifth
shadow may also be easily met. The long list of
advantages claimed by Mr. Maurice as accruing from
the increased illumination will, in reality, be realised by
the combustion tube lamp, and on the other hand it is
doubtful if they will be conferred by the electric lamp.

In arriving at his figure of savings, Mr. Maurice
assumes that electric lamps are not extinguished in the
mine. This is a fallacy, and I venture to say that after
electric lamps have been in use a short time thme
are more cases per day of lost or glimmer lights with
electric lamps than with the combustion tube oil lamp.
This latter certainly stands much more knocking about
than any other flame lamp without being extinguished,
and in any case it is capable of being relit and
immediately put into use without being sent out of the
mine. This cannot be said of the electric lamp, which
in 99 cases out of 100 must go out of the mine to be
overhauled and be examined. A careful man does get
the benefit of his care with the oil lamp, but not so when
using the electric lamp, as the loss of light more often
than not is the result of something entirely beyond his
control, such as a bulb collapsing or battery giving out,
or contacts failing.

As to the plea put forward by Mr. Maurice for more
highly skilled men taking charge of the electric lamps,
a man such as Mr. Maurice specifies, and who has good
electrical knowledge, usually has greater ambition than
to be consigned to a lamphouse. The flame safety lamp
maker does not ask for expensive electricians, or other
highly-paid workmen to deal with the flame lamps, as
the entire process of handling flame lamps is one of the
most simple things imaginable. Seeing that the charging
operation occupies many hours, and at the close of this
time the lamps have then to be assembled and tested, it
will be obvious that the manipulation of the electris
lamp is not so simple a matter as electric lamp makers
would have one believe, and in the majority of collieries,
especially the medium-sized ones, this must tell in
favour of the oil lamp as against the electric lamp.

Mr. Hargreaves stated that he had had 4,275 lamps in
use for 18 months, and during that time they worked
983,250 shifts, which works out to 230 shifts per lamp—
viz , equal to about an average year's working. Perhaps
Mr. Hargreaves will kindly check his figure of 18 months
again (dating back from last institute meeting). This
is important in this respect, that I calculate that about
now under ordinary circumstances they will be wanting
some more replacements in their cells, which would tend
to swell up the figures of cost. Another important point
is the quantity of oil lamps displaced by electric lamps,
,as obviously the figure of cost should be worked out on
this quantity in order to get a comparative figure.
Mr. Wordsworth, of Lancashire, reckons on 25 per cent,
of electric lamps as being out of condition for one reason
or another, and, obviously, to get a fair comparison of
the cost it ought to be divided into only such a quantity
of lamps as represent the quantity of flame lamps
displaced. If this be not done, the cost per individual
electric lamp may be got to look much lower than it
ought to do.

A very large colliery concern in Yorkshire (using
exactly the same lamp as Mr. Hargeaves) gave their
cost in 1913 at 4d. per lamp per shift, and this has been
extensively advertised, but in 1914 the writer was
informed that this cost had risen to |d. per lamp per
shift, viz., an advance of 50 per cent, in one year, and,
judging by the quantity of lamps lying idle waiting for
new batteries, which the writer saw on his last visit to
this colliery, the rate will have increased still further.

We have been told at such a large number of other pits,
especially those of moderate size, that their costs were
ranging from 5d. to 7d. per lamp per week, that the
writer feels confident that Mr. Hargreaves, even with
his larger quantity of lamps and proportionately better
chance of easing his standing charges, and cheaper
buying, will have a surprise in the future.

In a letter published in the Colliery Guardian on
January 15, 1915, Mr. Lincoln, the Lancashire repre-
sentative of the Ceag Company, gives the life of the
positive set of plates of the accumulator at nine
months, and says they cost 2s., which for 12 months
equals 2s. 8d.:—

The negative plate, he says, lasts double

that of the positive, viz..for J2months . .
equals ..................................   Is.	4d.

Viz., total for positive and negative plates

per 12 months ...........................   4s.	Od.

Which amounts per lamp per week of

52 weeks.....................    ..	0‘925d.

Electric, current he assumes to cost 3§d.
per 100 cells per day. equalling per
lamp per week of five days............. 0’175d.

He estimates consumption of 3 bulbs per
year, which, at say lOd. each (which is

.a low figure) equals 2s. 6d. per year... 0’577d.

l’677d.

So that these few items alone overtopped Mr.
Hargreaves’ figures of cost. To the above figures
should be added depreciation, and in view of the
experience at other collieries where lamps do not last
more than three years, I think that the depreciation
of Id. per lamp per week would be little enough, this
making a total for the four items amounting to 2-677d..
labour excluded, and this includes nothing for the
costly renewals to accumulator cases, contacts, lamp
cases, apparatus, and outer glasses, acid and additional
spare lamps, nor for interest on capital; and if the
electrician’s extra labour and other incidental expenses
are added it will be seen that even taking the electric
lamp makers’ figures, which no doubt are on the most
favourable scale for the purpose, the cost works out
much higher than Mr. Hargreaves gives, and the writer '
is of opinion that it will be found in practice that much
more than three bulbs per annum are used, and ihat
the accumulator plates after the first year will not last
anything like the period given by Mr. Lincoln. In fact,
one firm states that the positive plates do not last more
than three months, nor the negative more than six
months, and that the makers’ man told them they did
not advocate putting in new positive plates with the
old negative plates, as thej did not work so well together.
So that if other collieries have similar results their
costs will run out three times heavier than shown by
Mr. Lincoln.

Mr. Wood, of Clifton and Kersley pit, gives his cost
of electric lamps at 4'7d. per lamp per week. This price
is for Lancashire, and in view of the comparatively low
figures shown in Yorkshire the writer would be glad if
some of these people would state the price they are
paying for the purchase of the “ Ceag ” lamp, as this
has an important bearing on the cost, as it is well known
that one of the conditions of the electric lamp competi-
tion was that regard would be had or given to the cost
of the lamp.

The information we have received from various
sources appears to indicate that electric lamp makers
themselves, when quoting for upkeep and hire of electric
lamps, quote a price ranging from 4d. to 6d. per lamp
per week, not including labour. Mr. .Maurice, in one
of his papers, has stated that “ . . . The life of a
lead cell ranges anywhere between . 50 and 300 cycles, or
perhaps a little more with some of the best types, and
to cost Id. per lamp per week.” Bulbs he also estimates
to cost Id. per lamp per week ; and repairs, per lamp
per week ; so that then he gets 2^d. per lamp per week,,
leaving out of account the many items in the figures of
Mr. Lincoln’s just refeired to.

If, instead of the lead accumulator, the more cosily
alkaline lamp is employed, then the cost of depreciation
will still be at least Id. per lamp per week even if the
life of the lamp is taken at six years (which the writer
considers to be much too long a period to take), and as
the cost of bulbs would remain at least the same as in
the lead cell, and repairs which cannot be avoided in
rough pit work would be more expensive owing to the
expensive material used in the alkaline cell, it is evident
that this lamp will be quite as expensive as the lead cell
type.

If lamp cabins using oil lamps were so arranged that
the men could walk in and take their own lamps in the
same way as at Bullcroft—and if it is permissible with
electric lamps I do not see why it should not be so with
oil lamps—the cost of working the oil lamps could be
reduced still further, and show a still greater saving as
compared with electric lamps.

Mr. Hargreaves mentions that out of the last 804
lamps received at the colliery, the starting candle-power
was 1’03, and the fin'shing candle-power at the end of
the shift was 0’76. Perhaps he will say if this candle-
power was taken with the outer glasses in position. If
not, the addition of the outer glasses would no doubt
reduce the readings. I notice Mr. Hargreaves gives a
specific instance of x 26 lamps being examined before
going into the pit and on coming out, but he does not
give the candle-power of these 26 lamps; hence it
occurred to me that the larger quantity of 804 may
refer to readings of bulbs only. lie mentions rejecting
certain bulbs which do not reach a certain standard;
these bulbs will no doubt be passed by the makers on
to some other less particular customer, whose men will
suffer accordingly, or otherwise the cost of bulbs will be
increased.

In connection with Mr. Hargreaves’s anticipation of
the arrival of the half-watt lamp, it may be of some
interest to members if I give the following information
of some rough tests carried out in our laboratory:—