334

THE COLLIERY GUARDIAN.

February 12, 1915.

CURRENT SCIENCE AND TECHNOLOGY.

Wire Ropes Research.

An interim statement has been made by Mr. Walter
Pitt, chairman of the committee appointed by the
Institution of Mechanical Engineers to consider the
methods of carrying out research on wire ropes. The
work of the committee has been interfered with owing
to the general confusion produced by the war, but the
following is a short resume of what has been done. Two
methods of work have received consideration :—

(1)	Tire collecting and analysing of data concerning
the life-history of ropes that have been worn out in
actual work; and

(2)	The method of experimental research.

As regards the first method, after careful considera-
tion the committee prepared a somewhat elaborate
tabulated schedule of questions. A large number of
these schedules were sent out, and the committee have
to acknowledge the kindness of the many friends who
filled them up. These schedules give particulars of the
rope itself, and details of the rope pulleys and the
method of reeving, also a statement of the work done
up to the time of renewing. A number of lengths of
the worn ropes have also been sent to the institution.
A preliminary examination of the scheduled data tends
to show the extreme difficulty of analysing the results,
owing to the large number of variables entering into
consideration, and therefore the attention of the
committee is now being more strongly turned in the
direction of research. With this in view, a preliminary
design of testing machine has been prepared, so arranged
that actual lengths of full-size ropes may be worn out
under accurately known conditions ; in this manner the
variables can be altered one at a time, and the relative effect
of each ascertained. Copies of the proposed design are
being circulated to the members of the committee, and
rough estimates have been obtained, and will be con-
sidered at an early meeting. Should it be found
practicable to proceed on these lines, it is anticipated
that much valuable data will be obtained, and that this
in its turn can then be used in the analysis of the
scheduled data already received.

Accidents from Electricity.

M. Joseph Libert, inspector-general of mines in
Belgium, has recently contributed to the Annates des
Mines de Belgique an exhaustive study of the accidents
caused by electricity in the mines, quarries and
metallurgical works of that country. It may not be
generally known that the regulations prescribed in
Belgium are founded upon the rules adopted by the
Verband Deutsche Eletctrotechniker, or German associa-
tion of electrotechnicians, amplified as circumstances
have demanded. In the works referred to 32 more or
less serious accidents due to electricity have occurred
during the period 1900-12, causing the death of 31
persons and injuries toothers; of the total four occurred
below ground, 11 on the surface at collieries, three in
quarries and the remaining 14 in metal works. Following
a detailed analysis of each of these accidents, M. Libert
draws a number of general conclusions.

Taking first the nature of current, he finds that 30
accidents were due to the employment of three-phase
current, at the following voltages: 6,000 to 6,500 volts,
five ; 4,200 volts, two; 3,000 to 3.150 volts, three; 500
to 550 volts, 16; 220 volts, one; 190 volts, two; 130
volts, one. It must be remembered that a large
proportion of motors are operated by pressures of about
500 volts and under ; on the other hand the figures
dispose of the common belief that low pressures are
safe. The danger is aggravated when the neutral point
is earthed; and the Belgian authorities have considered
that this system is not to be recommended, although there
is always a possibility of defects arising in insulation.
Discussing this question in Technique Moderne in 1912,
M. G. Capart recommended the use of water jets or
columns as a means of limiting pressure and affording
protection against overloads, due to static charges and
other causes, where the neutral point is earthed; but
M. Libert considers that such a system, from the point
of vi* w of safety, has many objections. To secure
safety, it. is necessary that the current should be broken
on all phases, and single-pole circuit-breakers are
condemned. Further, although the accidents occurring
during the execution of work in the neighbourhood of
live conductors have generally been attributed to
imprudence, it is important that switches and circuit-
breakers should be disposed in accessible spots. Again
in works, several fatal accidents have been due to men
falling upon machinery after receiving a slight shock,
which would not otherwise have resulted in death.
Where alternating current is used with incandescent
lamps, the pressure should not exceed 110 volts between
the phases, and this prescription is particularly
emphasised in the case of portable lamps. On the
subject of pressure generally, M. Libert points out that,
from experiments that have been made, it appears
that currents of low intensify have the effect of pro-
ducing fibrillary tremors in the heart, which result in a
contraction of the various muscular vessels of this
organ, and may easily result in death. Currents of
high intensity, on the other hand, attack the nerve
centres, and death in this, case is generally due to
asphyxia, so that artificial respiration may be effective.
M. Libert also points to the dangers of alternating
currents, where armoured cables are used.

In the Revue Generate des Sciences (April 30, 1913),
Dr. Langlois expressed the opinion that tensi< n is not
the principal element to be considered in an electrical
installation ; it entirely depends upon the intensity of
the current that it can provoke, which is related to it
only by the intermediary of the resistance of the body
or contact, in conformity with Ohm’s law. Thus the
danger of currents cannot be classified solely on the,
basis of voltage. Dr. Langlois, to emphasise this point,

cites several cases where death resulted with currents of
less than 100 volts, some of them continuous currents,
where the conditions of contact were peculiar. Dr.
Langlois goes so far even as to attempt a formula—viz.,
“ with low-pressure currents, a current of 70 to 100
milliamperes is sufficient to produce death by fibrillary
tremors of the heart, while with high potentials the
intensity intervenes only by the destructive effect of the
electrodes.” The resistance of the human body varies
between great limits, and in the interior of the body it
is practically non-existent. So far as the points of
contact are concerned, two factors intervene, (1) the
extent of the organic surface in contact with the
electrodes, and (2) the condition of dryness or moisture
of these surfaces. With dry hands, a resistance of
3,000 ohms or over may be obta ned, but where the
hands are moist this may sink to J ,500 ohms. Given a
resistance of 1,000 ohms, it is possible to have a current
of 100 milliamperes with a pressure of 100 volts.

As regards the duration of contact, with currents of
low intensity, i.e., from 20 to 25 million amperes, this
maybe prolonged, without causing death, for more than
a minute, but if further prolonged for several minutes
death may follow from rigour of the respiratory muscles,
inducing asphyxia. With currents of 60 to 80 milli-
amperes, the duration of contact exerts a palpable
influence; an animal that can resist for four seconds
will succumb wlien the current has persisted for from
five to six seconds.

Experiments have proved that the position of the
electrodes in making contact is very important, and it
has been found that the danger is greatest when the
current circulates between the lower members and the
upper members on the left side, since the cardiac muscles
are thereby placed in circuit. This opinion is contrary
to that of D’Arsonval. who considered it to be essential
that the current should act upon the nervous centres.

M. Libert adds some useful observations in regard to
treatment. This generally should be similar to that
employed in cases of poisoning. But if hyperthermia
has been produced—that is to say, if the body gives a
sensation of high temperature—it is necessary to
associate, with the efforts to restore respiration,
refrigeration of the skin. When the accident has
provoked fibrillary tremor of the heart, neither artificial
respiration nor heart massage will have the slightest
effect. As regards precautions to be observed by
rescuers, the latter should always avoid using two
hands, and, if possible, should use the leg in order that
the current may traverse the lower part of the body,
and not the region of the heart.

OBITUARY.

It is with regret that we have to record the death of
the Marquess of Londonderry, which took place on the
morning of the 9th inst. at Wynyard Park, his lord-
ship’s county seat in Durham, following an attack of
pneumonia. In the late nobleman we had a noteworthy
example of an inherited capacity for business and
statesmanship, doubtless due to the fact that he
combined in his person the blood of the Tempests, in
Durham, and the Stewarts, of Ulster. The former was
an ancient and distinguished family, owning large
estates in the rich colliery district of South-East
Durham, and the late Marquess took a deep interest in
the welfare of this heritage. Of his political career, it
is unnecessary to speak at length. Born in 1852, he
entered the House of Commons in 1878, succee ling
his father in 1884. He served as Viceroy of Ireland in
1886, acted as chairman of the London School Board
from 1895 to 1898, and filled the post of Postmaster-
General from 1900 to 1902, from which be was
transferred to the Board of Education, acting as Lord
President of the Council from 1903.

His reputation as a considerate landlord was of the
best, and no less can be said of his relationship with
the host of workmen employed on his estates and in his
collieries—8,000 in Durham alone. In England, Wales,
and Ireland his inheritance as a landed proprietor
comprised over 50,000 acres, but besides the knowledge
of agriculture requisite in the management of such
extensive estates, special business faculties were required
for the conduct of the coalmining in Durham, from
which he derived the greater part of his wealth. The
Marquess, however, had the power of grasping a situa-
tion with singular insight, and dealing with it according
to its demands. Thus he showed enterprise in every
department, improving his resources, modernising
equipment, extending the means of transport, and
generally developing the great industry established by
his illustrious predecessor, the founder of Seaham town
and harbour. The works, started in the early part of
last century on quite a desolate portion of the coast,
originated through a refusal of the River Wear Com-
missioners to grant certain privileges for shipment of
coals. The third Marquess, so the story runs, declared
that he would make the grass grow in the streets of
Sunderland rather than be frustrated in his commercial
plans, and, certainly, the construction of Seabam
Harbour could be termed unparalleled at. the time as a
private enterprise. In 1900 the railway which the third
Marquess had opened in 1855 was purchased by the
North-Eastern Railway Company, and about the same
time Seaham Harbour was incorporated as a public
company, and the Londonderry collieries at Seaham and
Silksworth were registered as a separate concern, the
Marquess who has just died becoming chairman of each
of the two latter undertakings, and a director of the

railway company. Since then the large colliery at
Dawdon has been inaugurated. . Last summer, when
the present war broke out, he arranged that the wives
of his Durham employees in the Regular and Territorial
Army should have not only free coals, but free house
room or a rent allowance, while, as additional proof of
his sympathy, he at once wrote a cheque for £1,000 for
the Durham County War Relief Fund.

[P/ioto, Elliott & Fry.

The Late Marquess of Londonderry.

A

His lordship’has’acted as president of the CoaljTrade
Benevolent Society, was a member of the River Wear
Commission, and, indeed, can be said never to have
shirked any of the public duties which his great
responsibilities entailed. He is succeeded by his son,
Lord Castlereagh, who already, in the House of
Commons and elsewhere, has given evidences of great
ability.

The death took place on Saturday of Mr. William Oswald
Kellett, J.P., of Sefton House, Lathom, Ormskirk. Mr.
Kellett was one of the best-known men in Lancashire
mining circles, and was managing director of the White
Moss Colliery Company, Skelmersdale - one of the largest
concerns in the West Lancashire coalfield and he was also
interested in several other mining undertakings. By pro-
fession he was a mining engineer, and had a very extensive
practice throughout England. He was also estate agent to
Lord Gerard, of Garswood Hall.

The death has occurred at his residence, Rydings Hall,
Birstall, of Mr. Alfred West, aged 75 years. He had been
chairman and managing director of the White Lea Colliery
Company, Birstall, ever since its formation nearly 30 years
ago. He was born of a colliery family which hailed from
Halifax, and his grandfather sank the original shaft
at the White Lea pit. Mr. West invented West’s simplex
safety hook for preventing overwinding, which is well
known and extensively used, and he was also associated
with Mr. Gillott in getting out a coal-cutting machine
which is still well known, and with Mr. Russell, geological
surveyor, in preparing a geology of the Birstall district,

The death took place recently at Grimsby, of Mr.
William Herman Hitzen, coal exporter, who up to the
outbreak of hostilities was German Consul at that town.

The death has occurred of Mr. William Henry Wood, a
director of the firm of Messrs. John Wood and Sons Limited,
Wisewood Steel Works, Sheffield.

News has reached Durham county of the sudden death
at Jerome, Arizona, U.S.A., of. Mr. Thomas Peacock,
mechanical engineer, formerly with the Charlaw and
Sacriston Coal Company, and, later, head of the mechanical
department of the Shelton Iron and Steel Company, Hanley,
England. After leaving Hanley, Mr. Peacock became
assistant director-in-chief of the work of the African Gold
Coast Railways, after which he spent two years in Canada,
later going to New Mexico and thence to Jerome, at
which latter place he held a responsible position with the
United Verde Copper Company.

The news of the death of the Hon. Drever Joicey, youngest
son of Lord Joicey, at the early age of 28 years, has been
received with much regret in coal trade circles in the north
of England. Mr. Joicey’s demise was due to internal
injuries resultant from an accident in the hunting field
about two years ago.

The death occurred last week of Mr. James M. Kelly,
a well-known resident of Birkenhead, who was a member of
the firm of Messrs. James Kelly and Son, coal merchants
and colliery agents, South Castle-street, Liverpool. Mr. Kelly
for many years took a keen interest in municipal affairs,
and was appointed a justice of the peace for the Borough
of Birkenhead in 1898, and he also took an especial interest
in the work of the local education authority, of which he
was a member until the time of his death.

The death occurred recently, with tragic suddenness, of
Mr. William Holdsworth, coal merchant, of Rayleigh-street,.
Bradford. He was 58 years of age, and very widely known
in the city.

Following closely upon the demise of Mr. R. L. Kirby,
the directorate of Messrs. Bell Bros. Limited, has been
further depleted by the sudden death of Major Walter
Johnson, J.P., which occurred on Tuesday at the residence
of his son-in-law, Mr. Harald Dixon, of Red Barns, Redcar.
On his marriage, in 1871 to. Margaret Florence, the daughter
of the late Sir Lowthian Bell, Bart., he retired from the