1168

THE COLLIERY GUARDIAN

December 4, 191.4

lamp, and not the cost of labour. His reason for leaving
out the cost of labour was that in every lamp room
owned by the company the charges had remained exactly
as they were when running oil lamps, and where there
was a slight difference it was in favour of the electric
lamp. Another reason for leaving out the cost of
labour was that they had oil lamps offered them at a
price per week; they found that the oil lamp people
asked 2^d., as against the 14d. which he had showed the
electric lamps were costing.

Another matter upon which he thought he could speak
with some authority was with regard to the candle-power
of the lamps. His company did not accept whatever
the electric lamp people liked to tell them; every bulb
sent to them was subjected to a photometric test. The
result of an observation of the last 804 lamps received
at their collieries showed an average candle-power at
the beginning of the shift of 1-03; the same lamps at
the end of the shift showed an average of 0-76-candle
power. That, of course, was well within the Act. It
was stated at the previous meeting that electric lamps
should show a light of 1-candle power throughout a
nine hours’ shift. That, of course, was not correct—
that candle-power did not come into operation until
•January 1, 1916—that was, at any rate, his reading of
the Act, and his authority was the Colliery Manager's
Pocket Book. But a much stronger point to his mind
in that connection was that, even if it were not quite
up to the candle-power, he would be a very bold man
indeed who would say that the lamp people, who had
given such improvements in the electric lamp of late,
would fail to give them increased power in the little
bulb of the miner’s lamp. They knew what the passage
from the ordinary carbon filament to the metallic fila-
ment meant, by which the light was doubled at half
the cost, or something of that sort, and they were now
on the point of being introduced to the half-watt lamp,
which was going to give them double the light at the
same expenditure of power. Therefore he thought the
hope was altogether in the direction of the electric
lamp. He also desired to point out that a great deal
depended upon the manner in which a lamp was tested.
If they tested an oil lamp which was supposed to give
l|-candle power, they might get it on the flat way of
the flame, but tested the narrow way it would probably
drop to something under one. So that it would be best
sav if tbn lamps were tested ell round, and whether
the same lamps were tested at the beginning and end
of the shift. It was of no use testing one set of lamps
going in and another, set of lamps coming out; if they
did they would get rather absurd results, in some cases
at all events. He had asked for tests to be made of
some of their lamps, and one of his assistants took tests
of 26 lamps as they went out of the lamp room—took
them indiscriminately—and then at the end of the day
checked 26 as they came in. The result was that he
had 0-01 difference between the outgoing and incoming
lamps.

The question of accidents to the lamps, as mentioned
in the paper, was also a staggerer to him. At his col-
lieries they took very particular records of the number
of lamps which were holed by the miners’ picks, and he
could give them the result. Of the 4,275 lamps they
had in the year ending October 31, 1914, at five pits, a
total of seven lamps so holed by miners’ picks. That
represented a total number of nearly one million shifts
worked by the ‘miners, and in only seven cases did they
hit the lamp with a pick. An experiment was given
bv which it was shown that if a pick penetrated the
electric bulb an explosion might be produced, and he
believed an explosion was produced. He did not know
whether the second bulb could be penetrated by a
miner’s pick—he very much doubted it—but with the
most careful records taken at their collieries, they had
not, a single one so broken, and the total of lamp glasses
broken from all causes amounted to 215 in the year—
that included glasses broken in the lamp room, by screw-
ing them up, broken bv orons being knocked out, by
bumping the standard of the lamp—for nearly a million
shifts.

On the question of nystagmus, he thought it
would be folly to expect immediate results, but
they had had immediate results at their collieries;
they had a very considerable number of men
who had suffered from nystagmus now back work-
ing with electric lamps; three men went back on the
introduction of the electric lamp asking to be given a
nlace, and all of them had worked ever since, and one
had joined the Colours, so that his sight was evidently
good enough to sight a rifle.

Mr. W. D. Lloyd, referring first to Mr. Maurice’s
paper, said he was very much of the*same opinion three
or four years ago, and perhaps of the same opinion as
Mr. Hargreaves was to-day, and as a result of that he
had had practically three years’ experience with 1,000
electric lamps. Recently fte had had experience of
several hundred of the new type of oil lamp, and if they
had not entirely altered his opinion on the subject, they
had gone a long way towards doing so. The whole
question turned on two points—which lamp gave the
better light, and which was the safer. Mr. Maurice
would, he hoped, excuse him saying that his remarks
seemed to refer to the type of oil lamp which had been
in existence for the last 30 years, but during the last 12
months or so there had certainly been vast improve-
ments—Mr. Hailwood’s lamp and others, which, if not
actually on the market, might be so before long, which
undoubtedly would prove as good, and he thought he
might say give even a better light than the electric
lamp. There might be something to be said for the
w’hiter light of the electric lamp, because it certainly
was a very nice light, but unfortunately owing to the
way the lamp was made, and to the failing of the accu-
mulators, they could not get the maximum light for
the whole shift, and as the bulbs carbonised wi’th age,

and the accumulators deteriorated, they did not get
anything like the maximum, after having the lamp
going for about six months, or something like that. Then
as regards the question of safety, Mr. Hailwood gave
them some very interesting experiments. The oil lamp
extinguished itself as soon as the atmosphere was explo-
sive, 'and therefore they could not get an explosion with
it if the lamp was sound. On the other hand, the elec-
tric lamp went on burning independently of the sur-
rounding atmosphere, and if it was broken in an
explosive atmosphere, Mr. Hailwood and other people
had proved that if both glass and bulb were broken,
they could get ignition in an explosive atmosphere.
Then undoubtedly there was this much to be said for
the oil lamp, that a man using it had a distinct warn-
ing when the atmosphere in which he was working
became explosive, or was likely to be explosive, whereas
the man with an electric lamp did not have such warn-
ing. So that, on the whole, it seemed to him that the
question of safety also turned in favour of a good oil
lamp.

He was sure the institute was very much indebted
to Mr. Hargreaves for the details he had given with
regard to electric lamps, and he would like to ask him
to give them those particulars in detail, because he was
sure they would prove of great interest to all. As
regards the cost, he could not at the moment give such
accurate details as Mr. Hargreaves had, but he thought
they, had all come to the conclusion that electric lamps
could be run rather cheaper than they had expected, but
at the same time there was a great difficulty in always
keeping them in good order, and that was where he
thought Mr. Maurice’s argument as regards the saving,
of time lost in using electric lamps in place of oil lamps
was rather unsound, because it did not take into account
the fact that electric lamps did unfortunately go out
during a shift, and that there was a considerable loss of
time from that.

Referring to Mr. Hailwood’s paper, or more particu-
larly to the lamp itself, there was room for improve-
ment, although he thought it was undoubtedly a good
thing, and was likely to revolutionise the lighting of
pits to a certain extent. One of the chief difficulties
was keeping the flame of the lamp central, or rather,
keeping the inner glass central with the flame of the
lamp, and he was personally in favour of having a round
hole round the wick instead of the rectangular hole that
Mr. Hailwood usually supplied. As Mr. Hargreaves
had said, there was no doubt the bulbs of the electric
lamp might be improved in the same way as the larger
bulb had been improved, by having nitrogen inside
instead of a vacuum, but he did not think the electric
lamp could be improved very much; there was so much
weight in it; unless there was some revolution in the
accumulator itself, he did not think they could get a
larger charge out of it. But just as the metallic fila-
ment had. taken the place of the carbon filament, it
was possible that a better light might be obtained, and
in competition between the two rival illuminants he had
every hope that before a very long time a very much
better light could be obtained for the miner, just as
to-day he certainly had a very much better light than
he had three years ago.

Dr. Court (Staveley) said he was rather struck by the
question whether the white light of the electric lamp
would be more likely to reduce nystagmus than the
yellow light of the safety lamp. His argument had
been that the nearer they were able to approach to
daylight the better it would be, but he recalled an
experience of pits 23 or 24 years ago, when candles in a
tin can lamp afforded the illumination; this was, of
course, a yellow light, but there was not a case of
nystagmus in the whole Cossall Colliery. That led him
to think that the light had a great deal to do with the
disease. That brought them to the question of candle-
power—and that reminded him that where candles were
used to-day in pits that were free from gas, there was
very little nystagmus, and the eyes of the men did not
suffer—so that he could hardly say that the quality of
the light, whether yellow or white, had very much to
do with the reduction or alleviation of the disease; he
was pleading for the quantity of the light. There was
one point he had to make against Mr. Hailwood’s lamn
—as, indeed, he had against all miners’ lamps in which
oil was used—and that was that the light was cut off
bv the bonnet and the base. There might be the requi-
site candle-power, and it might be maintained for the
whole of the day, but he understood that the miners had
to hang their lamps in the pit, and the consequence was
that there was no diffusion upwards of the light, and
that as the man was constantly moving up and down,
his eyes were in the light at one moment and out of
it the next, the light being cut off by the bonnet and
the base of the lamp, and there was the constant altera-
tion of the contraction and dilation of the pupil of the
eve owing to the movement of the man. In the caso of
the electric lamp the light was more diffused like that
of a candle. He had asked the manager of Bull-
croft Collierv to send him the record of the cases of
nystagmus during the last 12 months. From his letter
he learned that the total pavments to men afflicted with
nystagmus during that period was £47 15s. That, he
believed, would bear out the president’s remarks as to
the reduction in the cost of nystagmus in a collierv
working with electric lamps. Undoubtedly the men
were more comfortable, and were less liable to accidents.

Mr. H. F. Smithson said he had had a good deal of
experience with Mr. Hailwood’s lamp, and he did no1
think anyone could dispute the fact that Mr. Hail-
wood’s lamp would give a continuous light of 1-candk
power—a minimum of that—during the whole of the
shift, if it was in a normal working place. Then they
had the president’s experience. He had tried both

lamps, and had them both tried by all sorts and condi-
tions of men, and to-day if he had to choose he would
most certainly put in oil lamps. He did not disagree
with Mr. Hargreaves’s figures, but he did disagree in
principle with the cost of l|d. per week per lamp, which
he thought was extraordinary low for electric lamps. He
would have thought it would have worked out at twice
that, or probably a little more. Then, of course, there
was the question of making examinations, and testing
for gas, etc.; personally, he would very much rather
have an oil lamp to walk round the pit with to make
his examinations than carry an electric lamp and one of
the instruments which they had had put before them
that afternoon. The oil lamp he thought gave a nicer
softer light, and that was the experience of colliers
with whom he had talked on the question. There was,
of course, something in what Dr. Court said about
diffusion of light, but he was not sure whether that
could not be overcome in some way by having some sort
of a reflector on the oil lamp. He believed if Mr.
Hailwood persevered with his lamp, as he had done for
the last 12 months, that it was possible of improve-
ments.

Mr. H. W. Ravenshaw, referring to Mr. Maurice’s
remarks as to the necessity for proper attention in the
lamp rooms, said he had had a good deal of experience
in visiting lamp rooms, and although there were, it was
true, many wooden legs to be found at them, still they
had always managed to keep the oil lamps very clean,
and, as a rule, very well indeed; but the care of the
electric charging apparatus was not so often satisfactory,
and he frequently found the lamps standing on wood
soaked with sulphuric acid; there had been a number
of serious fires due to the fact that there had been a
leakage from a leaky cell to the contacts of those stand-
ing below. At a good many places now the lamps were
stood on glass instead of wood, which was a great
improvement with regard to safety; men had to be made
to understand that they could not wipe up sulphuric
acid as they could oil with cotton waste. The fault in
most cases that he could recall was that the charging
arrangements were very defective, and that was where
they might have to look for a great expense to the cost,
and in the matter of cleanliness. Again, he had always
been against the use of celluloid, though he was afraid
he would be absolutely in the minority; but, in his
opinion, it wras highly desirable to dispense with so
inflammable a material.	,

Mr. W. Hay (Messrs. Newton, Chambers and Com-
pany Limited) said he had tried Mr. Hailwood’s new
lamp, together with the electric lamps, and had bqen
rather more than favourably impressed with the former.
He thought Mr. Maurice was wrong in stating that
there had been very little improvement in the amount
of light in the safety lamp during the last 20 or 30
years. He was very pleased to have the opportunity
of speaking after his old friend, Dr. Court, on the ques-
tion of nystagmus. He was one of the doctor’s con-
verts, and he was sorry to say that since he had come
into Yorkshire he had rather doubted whether he could
follow his lead any longer. When he first started
mining he had a great deal to do with pits where candles
were used, and such a thing as nystagmus was never
heard of. Later on, taking charge of a deep pit colliery,
he had a large number of cases of nystagmus. Unfor-
tunately for his theory, at an adjoining colliery to his,
working exactly the same seam and at the same depth,
where they used candles, there were a greater number
of cases of nystagmus than at his colliery where lamps
were used. Since coming to Yorkshire he had bad
charge of collieries employing over 4,000 men, and
where lamps had been used for the whole of the col-
lieries for 20 years, and to-day they had not got a
single case of nystagmus, so that at the present moment
he really did not quite know where he was in the matter.
He ventured to suggest for Dr. Court’s consideration
whether working coal at certain depths had not some-
thing to do with it. He thought they had to go further
to seek the. real cause of nystagmus, and he was rather
inclined to think that the question of light alone would
not account for it.

The President said on the question of cleanliness he
had in his hand a copy of the electrician’s report on
the lamp rooms at some of their collieries. The lamp
people sent round an inspector every two or thre^
months to see if the lamp rooms were properly kept,
and to point out any faults. That report he would
read. Generally the inspector reported that the lamp
rooms were well kept, and the contact points in good
condition, etc. They found it necessary, added Mr.
Hargreaves, to put some non-conductor on the shelves,
and had glass provided to prevent sparking, etc.

Mr. A. C. F. Assinder considered Mr. Hargreaves’::
figures rather astonishing, and said he would like to
point out that up to the present he had had his lamps in
use for only about 18 months. After he had had them
in use for about three years he believed he would find
a very greatly increased cost in regard to spares; he
would be very fortunate if he did not find the bottoms
of many of his outside parts dropping out. He said
already that there was an appearance of rust from
external sources, but he would be rather inclined to
think that that appearance of rust was more likely to
be from acid being spilled over the part of the lamp. He
gathered that a lamp station, if it was an electric one
must be equipped with a staff of electrical experts. This
would be a very serious inconvenience in a colliery,
where, as a rule, he believed, the lamp stations were
regarded as very useful places for putting disabled men
to work. There was another point in favour of electric