412

THE COLLIERY GUARDIAN.

March 3, 1916.

CURRENT SCIENCE

Turbine Pumps for Dip Drainage.

Dip pumping is very often required in colliery prac-
tice, and some engineers are of the opinion that this
problem is'one which is unsuitable for turbine pumps,
but the difficulties can be overcome by the following
method described by R. H. Willis in a paper read before
a joint meeting of the National Association of Colliery
Managers and Association of Alining Electrical Engi-
neers. The pump is mounted on a trolley, which is so
designed as to keep the pump horizontal. The pump is
'so arranged that a varying number of impellers can be
brought into operation from time to time, the chambers
not required being replaced by dummy stages, which are
removed as required. The pump starts to work against
a minimum head, and with only one impeller, say, in a
four-stage pump, in operation, all the remaining
chambers in the pump being dummies, with, of course,
a clear waterway through them. The motor is some
10 per cent, larger than is actually required, and is of
the variable speed direct-current type. As the pump is
lowered, shunt resistance is inserted in the motor field,
and the motor speeded up until a point is reached when
the head dealt with is equal to that of two impellers
when running at the lowest speed of the motor. Two
impellers are then put in the pump, and the motor
worked at its lowest speed. . The same cycle of opera-
tions is followed until ultimately the pump has its full
number of impellers. By this method the maximum of
water is obtained with the minimum amount of current
throughout the whole period, and the total result com-
pares favourably with the performance of a ram pump
which has generally been used for this purpose. Practi-
cally the same arrangement can be followed when the
Dump is driven by a three-phase motor, but owing to
the motor speed being constant, the working is not
quite so flexible as with a direct-current motor, and
resort has to be made to throttling by means of the valve
on the delivery side after changing the number of
impellers, so as to prevent the motor overloading itself
at this point.

When considering the purchase of turbine pumping
plant, the following points should be carefully con-
sidered :—(a) The pump should be capable of being
easily dismantled and erected. In this connection, the
author does not advocate the type of pump in which
the chambers are placed inside a cast iron containing
shell, (b) All wearing parts should have ample area,
and be capable of renewal on site, (c) All similar pumps
should be made interchangeable, and effective methods
should be adopted to obviate the end thrust.

When installing-a turbine pump, the following points
should be borne in mind :—(a) The pump should be
fixed as close to the water to be lifted as possible, and
the suction pipe must be made airtight, leakage of air
being a fruitful source of trouble with this type of pump;

• (fi), the suction pipe should be provided with foot valve
and strainer, and if the water contains grit or dirt, a
dividing wall in the suction pond to allow the dirt to
settle before reaching the suction pipe is an advantage;
(c) a vacuum gauge is an important accessory on the
suction side, as it indicates any leakage of air; (d) on
the delivery side all sharp bends in the pipe line should
be avoided; (e) a sluice valve and non-return valve
should be fixed between the pump and delivery pipe,
both provided with a by-pass valve, so that the pump
may be primed from the water in the rising main.

The United States Bureau of Mines in 1915.

A summary of results obtained by the Bureau in 1915
has been issued by the Director, Van H. Manning. The
results, he says, are now beginning to show in a sub-
stantial manner in decreases in the number of lives lost
in coal mining. While the complete fatality figures for the
year 1915 are not available, he has every reason to believe
they will show the smallest number killed in any year
since 1907, and likewise the smallest death rate per
1,000 men employed. The improvement during the last
three years has been remarkable. It is known that
slightly more coal was produced in 1915 than in 1914,
which would indicate more men employed, and there-
fore a decreased death rate below 1914. The Bureau
claims that its work has served to stimulate a nation-
wide movement for greater safety in all industries, and ■
that the value of this work cannot be measured in dollars.

During the year L. Al. Jones, mining engineer, under
the general supervision of George S. Rice, chief mining
engineer, carried on a series of explosion tests at the
Bureau’s experimental mine at Bruceton, Pennsylvania.
The results promise to be of great value. The main
feature of this work is standardisation of the methods by
which the inflammability of coal dust from typical coal
mines is tested, with and without the presence of fire-
damp, and by which the amount of rock dust or other
inert matter that must be added to make the coal dust
safe is determined with reasonable precision. In con-
nection with these tests, rock dust barriers, for
stopping explosions, designed by the chief mining
engineer, were tested. Several of the barriers designed
during the preceding year were modified to make them
x more effective. Also, a new barrier was designed which
proved successful in many tests. Application for
patents covering the barriers has been made, and the
patents, if granted, will be dedicated to the public. The
engineers of the experimental mine, in co-operation with
the Pittsburg Coal Company, began a test to determine
the efficiency and cost of rendering coal dust inert by
rock dust in a commercial mine. About 2,000 ft. of
entry in such a mine was sprinkled with limestone dust,
and was inspected every two weeks by one of the
Bureau’s engineers to determine to what extent the rock
dust had been contaminated by coal dust, and to arrange
for' further rock dusting if necessary. The results so
far indicate that unless much coal dust is spilled along
roadways, the method will give better protection against '

AND TECHNOLOGY.

a coal dust explosion, and, under the conditions tried,
might be cheaper than the use of water on a large scale.

The Bureau has been making an investigation of
safety lamps, both flame and electric, for coal miners,
in the course of which thousands have been tested.
During the year H. FI. Clark, the Bureau’s electrical
engineer, continued investigation of portable electric
mine lamps, devising and conducting tests for safety and
practicability. Probably the greatest advance through
the Bureau’s efforts has been the improvement of the
lamp bulbs. With a view to devising rescue apparatus
better than that of foreign make now used, investiga-
tions have been carried on at Columbia University. by
W. E. Gibbs, engineer of special research. Yandell
Henderson, consulting surgeon, acted ‘ in an advisory
capacity. Such a breathing apparatus, a self-contained
unit wholly on the back of the user, has been developed
during the last year by Air. Gibbs. It is light, and its
parts are all substantially protected against injury. By
means of a special device, oxygen is fed at the rate it
is used, and although plenty is available for the wearer
when working hard, none is wasted when he is resting.
An unusually efficient carbon dioxide absorber that
liberates little heat is another feature of the apparatus.
Caustic soda, which is much cheaper than the potash
salt formerly thought necessary, is used as the absorbent.

Several States have enacted stricter laws regarding
electrical equipment in mines, these laws being based on
recommendations made by the Bureau.

SOME RECENT DECISIONS UNDER THE

WORKMEN’S COMPENSATION ACT.

[Specially Contributed."]

Conflicting Medical Evidence.

When acting as arbitrator under the Workmen’s Com-
pensation Act the county court judge has probably no task
more difficult than that of dealing with conflicting medical
evidence, and there is therefore something to be said for
the contention that the Act should be amended to make it
compulsory for a medical assessor to sit with the judge. As
the Act stands, the attendance of a referee is entirely within
the discretion of the judge, paragraph 5 of schedule 2 simply
providing that “ a judge of county courts may, if he thinks
fit, summon a medical referee to sit with him as an
assessor.” The presence of a medical assessor might well
be made obligatory on the application of one or both of the
parties. Natural acumen no doubt enables the judge to
reach a just conclusion in the majority of cases, but the aid
of a medical assessor would enable him to do so more quickly
and surely. A claim recently heard at Wigan provided an
example. The applicant, who *had worked as a bricklayer
for the Pemberton Colliery Company Limited, fell on his
knees when getting out of a cage on arriving at the surface
of one of the company’s pits, a cartilage of his left knee
being dislocated. In the infirmary he underwent an opera-
tion for the removal of the semi-lunar cartilage from the
knee. The question now was whether, as the employers
contended, the man was fit to resume work on a certain
date. On behalf of the workman the infirmary surgeon said
there was some thickening of the lining of the joint, and a
distinct grating when the joint was moved, the lost cartilage
having acted as a buffer between the two bones, the femur
and the tibia. Witness did not think the man was fit for ladder
or kneeling work, but admitted that he could do some light
work standing. The effect of removing the cartilage was
that the man lost part of the natural movement of his joint.
As a rule in such a case a man would get back to, work in
two or three months. The company’s medical man said that
about a week before the compensation payments were stopped
he came to the conclusion that, applicant had been off work
long enough, and was exaggerating the symptoms. The
witness found no adhesions or thickening. There was some
grating, but it was found in both knees, though more in the
left than in the right. Another medical man said that about
a month before the hearing, he and the previous witness
examined the applicant. He found no swelling of the joint
and no limitation of movement, and formed the opinion that
the way in which the applicant moved was largely a habit.
He agreed with the previous witness as to clicking or grating
being present in both knees, though perhaps a little more
marked in the injured knee than in the other. He did not
think the symptom had any connection with the accident or
the operation, and added the opinion that it was present in
40 or 50 per cent, of industrial people about 40 or 50 years
of age. AVitness had had it himself for 20 years, but moved
without any pain and was of opinion that there was nothing
to prevent the applicant from kneeling, and that no pain
would be caused thereby. Ultimately the judge decided in
favour of the company, allowing them costs on scale B, and
refusing the applicant a declaration of liability.

Failure to Give Notice.

Under the Workmen’s Compensation Act it is rightly
required that notice of an accident must be given to the
employers as soon as practicable. Failure to give notice,
however, is not a bar to proceedings unless it appears that
the employers were prejudiced in their defence by the delay.
That employers require a safeguard of the kind is frequently
shown, a recent illustration being given at Wigan in a
claim against the Shelton Iron, Steel and Coal Company
Limited. The case for the applicant was that his work
consisted in holing and shovelling earth. While throwing
earth from his shovel he had to turn half round, and in so
doing twisted a muscle in the middle of his back. He con-
tinued to work till the end of the shift, but was in pain .
all the time. On the following day he felt ill, but had been
unable to do any work since. About two months afterwards
he went to the colliery to try to work, but was unable to
continue. Soon afterwards he went to the company’s offices
and asked for compensation, which was refused after
examination by the company’s medical man. He informed
his union about the accident, but when asked to explain the
delay in giving notice to his employers, said that he was no
scholar, and did not know how to go about it. > In cross-
examination he admitted that his panel doctor examined him ’
the day • after the alleged accident and treated him for
lumbago, though told that applicant had injured his back.
He had National Insurance sick pay for 26 weeks. An
infirmary doctor said that he examined the applicant fully

three months after the alleged accident and found evidence
of a sprain to a lumbar muscle. He was of opinion that
appearances were consistent with the story told by the man,
who, however, was asked to come again in a fortnight for
electrical treatment if he did not improve, but did not return.
The accident was supposed to have happened at 9 o’clock
in the morning, and witness thought it possible the man
could work until 2 o’clock, notwithstanding the pain, which,
however, would get more severe as time went on. Another
medical man deposed to examining the applicant on the
morning of the hearing, and also about three weeks before.
He found that movement of the back was limited, in all
directions, and considered that the appearances were con-
sistent with an accident such as the man described, and that
the condition of the muscle, which was much twisted on
the left side, could not have arisen from lumbago. A
medical witness called for the employers, said that the
applicant was prematurely aged and walked lame with his
back bent. There was a good deal of stiffness in the lower
part of the back, but witness found no wasting of a muscle
of the back and no depression, and believed the pain was
due to rheumatism, which was of long standing, and had pro-
bably been aggravated by the man’s condition. Witness
was also of opinion that the accident was a slight one, that
if the muscle had been torn, as was 'alleged, it would have
been impossible for the man to go on working for five hours,
and that the conditions were consistent with rheumatism.
Another medical witness for the company was unable to
discover any signs of an accident when he examined the
applicant about three months after it was alleged to have
occurred, and saw no appreciable waste. Witnesses with
whom the applicant had worked testified that he had never
mentioned any accident, but had complained of a pain in
his back before the accident was supposed to have occurred.
Mr. R. Fisher, the under-manager, said that the applicant,
on his first visit, complained of lumbago, but not of an
accident. Afterwards he brought a paper claiming com-
pensation, and when witness remarked that nothing had
previously been said about compensation, the applicant
replied that the infirmary doctor had advised him that he
had had an accident. Only a week before the applicant had
told witness he was suffering from lumbago. Owing to the
conflicting medical evidence the county court judge decided
to obtain the opinion of a medical referee, who reported that
he did not find any inequalities (abnormal thickenings or
depressions) in the muscles of the back, and was of opinion
that the man’s disability arose from rheumatoid disease, and
was not the result of an accident. On that, his Honour held
that even if something in the nature of an accident did
occur, the applicant was not now suffering from the effects
of it. He also held that the applicant did not give notice as
soon as practicable, that there was no reasonable ground
for delay, and that the employers had been prejudiced.

Insanity and Nystagmus.

An unusual case was heard at the Merthyr County
Court, before Judge Bryn Roberts, in which Catherine
Jones, Merthyr ATale, sued Messrs. Nixon’s Navigation
Company for compensation in respect of the death of her
husband, Walter Jones. The deceased contracted, miner’s,
nystagmus in April 1914, and received compensation until
December of the same year, when he was appointed steward
of the Hibernian Institute, Merthyr Vale. He was still
suffering from the effects of his illness, it was stated,
and laboured under the idea that he was not carrying out
his duties satisfactorily. He twice tendered his resignation,
but on the first occasion was persuaded to withdraw. The
second resignation was accepted, but on the day before it
would have terminated he was found dead upon the railway,
where he had been run over. At the inquest the jury
returned a verdict of “ Suicide during temporary insanity.”
Plaintiff sought to show that the insanity was the result of
the nystagmus. Several witnesses averred that Jones was
strange and unsettled as the result of the disease, and Dr.
Richardson White described the nystagmus as the worst
case he had seen. Jones had to grope his way into the
surgery, and. his mental condition was such that witness
came to the conclusion that he ought to be watched. Other
medical evidence for the applicant was to the effect that the
insanity was caused by worry due to' the persistence of
the disease. • Dr. M’Ghie, compensation doctor to the
company, said he had never known insanity to arise from the
disease.

After hearing other medical evidence, the judge found
for the respondents.

The Court of Appeal had before them another claim for
compensation for death from suicide following an acci-
dent. The facts were stated to be as follows :—John
Grime was a mechanic employed at Brook Mill, Ghorley.
On December 4, 1913, while Grime was grinding a pick
some pieces of metal flew into his eye. He was medically
attended, but continued at his work. On December 20 he
was found dead, having shot himself with a revolver. The
coroner’s jury returned a verdict of “ Suicide while
temporarily insane.” On an application for compensation
by the dependants, the County Court judge held that the
death was due to suicide while the man was insane, that
the insanity was due to the injury to the eye, and that the
injury was due to accident arising out of, and in course of,
the employment. He accordingly awarded compensation.
The employers appealed, and the appeal was sustained by
the Court of Appeal.

In giving judgment, the Master of the Rolls said :—“ It
is not necessary to decide what is the effect of insanity on
claims such as this, because the Court are agreed there
was no evidence of insanity. There is a great difference of
opinion even amongst medical men on the question of
insanity. But it came to this, the evidence of the doctors
was merely opinion, not based on definite fact; and in the
present case all the facts seemed to negative insanity.”
The Court was also against the dependants on the question of
notice. It was argued for them that the provisions of the
statute regarding notice did not apply to dependants. The
Court held, however, that the section regarding notice
undoubtedly applied to'dependants as well as to the injured
workman,

Hull Coal Exports.—The official return of the exports of
coal from Hull to foreign countries for the week ending
Tuesday, February 22, is as follows Amsterdam, 199 tons;
Christiansund, 47; Dunkirk, 2,090; Gothenburg, 1,304;
Havre, 619; Harlingen, 550.; Oporto, 1,454; Rouen, 4,935;
Rotterdam, 743; Savona, .3,190; total, 15,131 tons. Corre-
sponding period February 1915, 33,387 tons. These .figures
do not include bunker coal, shipments for the British
Admiralty, nor the Allies’ Governments.