January 31, 1913.

THE COLLIERY GUARDIAN

233

generally agreed that that was a case of ignition by
signalling apparatus, if not by signalling wires. Mr.
Saint referred to the obtaining of a good earth on the
surface. That was very much a matter of local con-
ditions. It was not always easy to find a good earth,
and that was a problem that tramway companies had
had to solve. After much difficulty, they arrived at a
means of providing an effective earth and at a test
which the Board of Trade now imposed on all tramway
concerns. They used two plates, the size depending
upon the nature of the ground. Cast iron was a
good material for the plates and lasted a long
time, but copper was, perhaps, better if the moisture
did not attack it. They buried the two earth plates,
connected them together, and connected them to the
rails. They were supposed, under the Board of Trade
Regulations, to test every month, and they tested in
this way. They broke the connection temporarily, and
applied a pressure of 2 volts by means of a secondary
battery between the two earth plates, and, by means of
an ammeter in the circuit, registered the current they
got. Under the Board of Trade regulations, with an
applied pressure of 2 volts they must get 2 amperes
or more ; otherwise, the earth was not effective.
Particulars of this test he had attached as a
footnote to the memorandum on the Electricity
Rules. In some places in the country it was not
possible to obtain that standard ; it depended upon the
nature of the ground. With a rocky ground, it was
difficult to obtain it; in clayey ground it was easy. Mr.
Saint mentioned having seen earth plates in water. That
was not a good thing; what was required was damp
earth round the earth plate. It was clear that water
was not right, because water was often used as a
resistance; and, obviously, if water was used as a
resistance, then it was not a thing to bury earth plates
in. What he had said also replied to Mr. Gregory’s
question.

A vote of thanks was accorded to Mr. Nelson, on the
motion of the President, seconded by Mr. Gregory,
and supported by Dr. Cadman.

Haulage Clips.

There was also a brief discussion on the paper of
Messrs. W. G. Salt and A. L. Lovatt, “ Some Notes
on Haulage Clips in Use in North Staffordshire,” which
was read at the last meeting. The writers of that paper
were also cordially thanked for their valuable contribu-
tion.

Letters to the Editor.

The Editor is not responsible either for the statements
made, or the opinions expressed by correspondents.

All communications must be authenticated by the name
and address of the sender, whether for publication or
not. No notice can be taken of anonymous communi-
cations.

As replies to questions are only given by way of published
answers to correspondents, and not by letter, stamped
addressed envelopes are not required to be sent.

RESCUE APPARATUS OF THE INJECTOR AND
NON-INJECTOR TYPE.

Sir,—With reference to the recent correspondence in
your paper regarding rescue apparatus, several of the
letters were replies to my letter, and I would state that
many of the points raised have not been contradicted.
In the meantime I may state that we have been
experimenting very extensively and have had made
special testing apparatus to record the pressure
of the air in the different pipes and fittings on the
apparatus. We have been successful in recording some
very interesting facts regarding the use of the
injector on breathing appliances. The injector type
apparatus maintains its positive pressure throughout
constantly, and the negative zone can only be caused at
an instant of time during deep inhalation, and this is
immediately restored upon exhalation. On looking
further into the matter and comparing it with the non-
injector type of apparatus, we find that to sacrifice the
injector means to do away with the efficiency of
regeneration. The inhalation air is also excessively hot,
and breathing is uncomfortable when any work is being
done, owing to the air circulation depending upon the
lungs as a circulating medium. In fact, up to the
present, the only advantage that the non-injector type of
apparatus has been able to claim is the certainty of a
positive pressure continuously. These points are all
agreed upon by the different experts. It is therefore
seen that the injector type of apparatus is more efficient,
gives cooler air, and does not put any strain on the
wearer’s lungs, the only disadvantage being (as men-
tioned above) that occasionally a zone of negative
pressure is formed.

Our experiments here have now resulted in our being
able to combine the safety of the positive type of
apparatus with the proved highest efficiency of the
“ Meco ” injector type apparatus, and we have been able
to bring our experiments to a successful conclusion.
We have inserted in the apparatus a special fitting,
which does not in any way interfere with the efficiency
and it neutralises any tendency for negative pressure to
form. This fitting also adds to the comfort of the
wearer, as it increases the amount of air available in the
apparatus. This pressure-equalising device absolutely
prevents the formation of any negative pressure in any
part of the apparatus, and.we absolutely guarantee this.
This device is one of the most important improvements
ever applied to rescue apparatus, as it not only removes
the negative zone air, but at the same time is an
indication of any leak which may be in the apparatus.
It therefore acts as a leak detector, so that it will be
impossible in the future for a man to go into an
irrespirable atmosphere with the “Meco” positive-
pressure injector apparatus with leaky fittings.

In summarising the advantages of this new apparatus,
we are able to retain the advantages of the injector with
the increased safety of the positive pressure. I might
state that this forms a satisfactory solution to the whole
of the controversy, and individuals who are interested in
this improvement we shall be pleased to give further
information upon hearing from them. I might state
that we are able to convert the present “ Meco ”
apparatus, where required, at a small additional cost to
the positive-pressure type.	H. Jenkins.

The Mining Engineering Company Limited,

Meco Works, Moorfields7, Sheffield.

January 27, 1913.

THE PROPOSED INSTITUTION OF MINE
SURVEYORS.

Sir,—In your current number I notice a letter from
Messrs. T. A. O’Donahue and W. H. Galletly advising
mining engineers and surveyors, who are established in
practice and eligible for election, to communicate direct
with the secretary of the Surveyors’ Institution, with a
view to being admitted as members of that body with-
out examination. Let me beg that no such step be
taken until some meeting of mine surveyors has been
held, and the matter thoroughly considered and dis-
cussed in all its bearings.

The Surveyors’ Institution is, in my opinion, mis-
named. Many of the members have little or nothing
to do with surveying. An acquaintance of mine, who
took the Penfold Gold Medal at the Surveyors’ Insti-
tution some years ago, told me that he had not used the
theodolite in the course of many years’ practice, and
had only handled a level once or twice. Other examples
can be cited, but this may be sufficient to put intending
applicants for membership on their guard.

The Surveyors’ Institution is no institution for mine
surveyors. I have no quarrel with that body, which is
a well organised and powerful one; but, in the interests
of mine surveying, I think it desirable to form an inde-
pendent institution, mainly for mine surveyors, if mem-
bership in the Institution of Mining Engineers, or in the
Institution of Mining and Metallurgy, is considered
inadequate for their needs. The prospects of such an
independent body should not be ruined by the rash step
proposed by Messrs. O’Donahue and Galletly without
the sanction of other members of their profession. If
the existing engineering institutes will not, or cannot,
adequately represent us, I am convinced that the sal-
vation of mine surveyors will come from themselves,
and from themselves alone.

I regret that the narrow spirit of nationality has
been allowed play in these islands, and that there is
a movement to establish an association of mine
surveyors for Wales only,

Mine surveying is a science, and will, I hope, be
regarded as such in the future. To import either
politics or patriotism into science is more than non-
sense—it is a sin. The object of a progressive science
is to extend the boundaries of knowledge—of truth—
and not to advance the interests of some nationality.

Let us forget ourselves, our parishes, our counties,
our country even, where it is a matter of science and
truth; let us imitate the example of the Institution of
Civil Engineers, the Institution of Mining and Metal-
lurgy, the Institution of Mining Engineers, and form an
Institution which will throw open its doors to all duly
qualified mine surveyors, whatever be their nationality.
Thereby we express the true nobility of the British
character, and follow the British policy of inclusion, not
exclusion. Thereby we shall take a position higher
than that of a mere trades union.

I have noticed in previous correspondence a tendency
to restrict the membership of the proposed association

to colliery surveyors only. This would be a serious
mistake, and a wrong to the great number of surveyors
who go abroad to take charge of the survey department
of various ore and stone mines, and who are so scattered
that they are unable to unite locally to form a body to
represent their interests. If the number of colliery
surveyors be considered too small to form a society
strong enough in itself, then should we look rather to
the ore mine surveyor for mutual support than to the
land and estate ugent and valuer of the Surveyors’
Institution.

The surveyor of ore mines needs as a rule higher
qualifications than his colliery colleague, and much
would be gained by his support. I challenge the
statement of Messrs. O’Donahue and Galletly that
“ the membership of the Surveyors’ Institution is
recognised as the hall-mark of the profession and would
constitute a higher qualification for mining engineers
and surveyors than any which now exist ” ; I believe (1)
that the said membership is not the hall-mark of the
mine surveyor’s profession; (2) that it is not recognised
as such; (3) that it certainly does not constitute a
higher qualification than, say, that of the Institution of
Mining and Metallurgy, which I merely instance as
being the one with which I am best acquainted.

Would it not be possible to arrange for a congress of
mine surveyors in London, Birmingham, or other con-
venient city in the slack time of the summer; perhaps
, the congress could be timed to coincide with the
Colliery Exhibition ?	L. H. Cooke.

Royal School of Mines.

January 29, 1913.

STATUS OF COLLIERY SURVEYORS.

Sir,—With reference to the letter on the above
subject in your last issue, I would like to suggest that
the writers give further particulars with regard to the
conditions under which the council of the Surveyors’
Institution will allow candidates to sit for examination.

The majority of colliery surveyors know very little
of the Surveyors’ Institution, and before saying that
they are prepared to sit for examination, they will, no
doubt, wish to have details as to the subjects of exami-
nation, age limit, fees, subscriptions, etc.

When these particulars are forthcoming, the colliery
surveyor will then be in a position to consider whether
it would be worth his while to take the matter up.

January 28, 1913.	W. B.

SURVEYORS AND MANAGERS’CERTIFICATES.

Sir,—May I beg to bring to your notice a matter
which I feel convinced must be of great interest to
numbers of your readers who find themselves in a
similar position to myself ?

There has been a good deal of correspondence as to
the hardships imposed by the new Mines Act upon the
working miner with reference to his chance of obtaining
his manager’s certificate. I belong to a class of men
who have been infinitely more seriously hurt by the Act,
that is, to have served three years’ articles to a mining
engineer, and then following the example of numbers of
our leading mining engineers and some Government
inspectors, I obtained a position as surveyor at a large
steam coal colliery in South Wales.

I sat at the first class colliery managers’ examination
in May last year, being duly authorised to do so by the
Home Office, and unfortunately failed. I applied for
my authorisation for the November examination under
the new Board, and two days before the examination
was refused, with the curt announcement that mine
surveying was not mining experience.

I should be inter* sted to know what experience it is if
it is not mining experience, but quite apart from that I
see no objection to any board making their own rules
to obtain the best class of men they can, and if they
desire to keep out surveyors for some reason not appa-
rent, I think in common fairness to the man, who has
done his very best to fit himself for his profession by
spending his own or his parents’ money in premiums,
books, classes, &c., and working for years for next to
nothing, the board might at least have had sufficient
feelings of fair play to give due warning, instead of
using the power they possess to absolutely ruin the
career of a number of men who have done their best to
fit themselves for the profession they have chosen.

Would-be Colliery Manager.

January 28, 1913.

In view of his appointment as under-manager at Plean
Colliery, Stirlingshire, Mr. James Jackson has been pre-
sented by the employees of Queenslie and Gorthamlock
Colliery, Shettleston, with a handsome gold lever watch,
together with a gold bangle for Mrs. Jackson.