June 20, 1913.

THE COLLIERY GUARDIAN.

1335

mentioned by any of the speakers—namely, the relative
cost of using reinforced concrete or other material, and
unless they could have some assurance that it would be
a cheaper material to use than what they were already
using, they were not likely to adopt it.

The resolution of thanks was heartily carried.

Prof. Dixon, replying to the discussion, said that it
was not so much want of faith that prevented the
general adoption of concrete, but rather excessive faith
in other materials. It was possible to design struc-
tures strong enough to resist any pressure, and even
to stand the strain of the various stratas to be
dealt with ; but as long as mining engineers
refused to consider these, and were content with
the failures of the props and joists put in, no
progress would be made. He believed that in regard
to such great disasters as had happened to concrete
buildings, they had been while structures were in course
of erection. For instance, supports had been taken obt,
and whole buildings had collapsed through the material
being green. He believed no building had ever been
known to collapse except in course of construction.
With regard to the failure of arches, he did not regard
that as a very serious matter. Reinforced concrete
would be safer than timber, and would have the
advantage that it would 'give ample warning before it
collapsed. At the university they had tested arches of
10 ft. span, and in some cases the arch had been brought
down for 6 in., but afterwards went back again. With
the exception of timber, he had never known a safer
material; and if it were used for arching, say, in a main
road, they would immediately be aware of anything
happening, and there would be ample time to prop it
up. He knew of a bridge built of the material having
100 ft. span. Signs of giving way were seen, and tlu
engineer built a prop under the middle of it, and so
prevented disaster. That showed that although they
had a good engineer, they had a bad designer. It was
quite true that they needed further experience, but the
time had come when people should use the material, and
so accumulate the experience for the general benefit.
The question of costs raised by Mr. Cockin was really a
very important question, but they had to remember that
the cost of timber must increase very largely in future,
owing to the very small amount of planting that was
going on.

This concluded the meeting.

MINING INSTITUTE OF SCOTLAND.

A general meeting of the Mining Institute of Scotland
was held on Saturday last, 14th inst., in the Heriot
Watt College, Edinburgh. In the absence of Mr.
James Hamilton, president, Mr. James Barbowman,
Hamilton, was called to the chair.

New Members

The following gentlemen were admitted to the
membership of the institute:—Messrs. H. H. W. Boyes,
mining engineer, Murrayfield, Edinburgh ; Donald
Boyd, colliery manager, Maryhill, Glasgow ; Fred.
Brownlie, mining engineer, Coatbridge; J. P. Burns,
mineral valuer, Portobello; John Gavin, mining engi-
neer, Uddingston; A. H. C. Guise, colliery manager,
Bengal, India; James Jack, general manager, Cumnock
Collieries, New Cumnock ; Wm. Paterson, underground
manager, Prestonpans ; and J. A. S. Ritson, H.M.
inspector of mines, Edinburgh. Associate member:
W. D. Robb, assistant mining engineer, Glasgow.
Student members: H. R. Dixon, mining student,
Kilsyth ; and R. W. McClellan, assistant mining
engineer, Leith.

Representatives on Institution’s Council.

The undernoted gentlemen were elected to represent
the Institute on the Council of the Institution of
Mining Engineers:—Messrs. J. T. Forgie, Bothwell;
R. McLaren, H.M. inspector of mines, Airdrie; James
Hamilton, Glasgow; Jas. Barrowman, Hamilton; C. A.
Carlow, Leven; R. W. Dron, Glasgow; George Gibb,
Rutherglen ; Douglas Jackson, New Mains; Charles
Latham, Glasgow University; Wm. McCreath, Glasgow,
James Nisbet, Coatbridge, Wm. Smith, Dalmellington
Iron Works, Ayr; James B. Sneddon, Oak bank, Mid
Calder; Wm. Williamson, Hamilton, and Wm. Walker,
H.M. inspector of mines, Edinburgh.

Testing for Firedamp and Blackdamp by Means of
a Safety Lamp.

Discussion was resumed on the paper contributed by
Mr. Henry Briggs, Heriot Watt College, Edinburgh,
on “ Testing for Firedamp and Blackdamp by means
of a Safety Lamp.” A summary of the paper, it may
be mentioned, has already appeared in our columns.

Mr. J. Balfour Sneddon, Oakbank, Mid-Calder,
said it would be recalled that at the last meeting of the
Institute a desire was expressed for further trials of

the loop device so’ strongly advocated by Mr. Briggs.
Accordingly a series of tests arranged for by Mr. Wm-
Walker, H.M. inspector of mines, had been carried out,
at Valleyfield Colliery belonging to the Fife Coal
Company, and Bothwell Castle Colliery, belonging to
Messrs. Wm. Baird and Company. Personally these
trials had proved to him that the loop in the hands of
an expert did show a gas cap clearer than the lowered
flame did in the case of the smallei’ percentages. Indeed
he might say that he had very considerable difficulty in
distinguishing between the fuel cap on the lowered
flame and the cap that showed on it when there was a
small percentage of gas present. The conclusion he
had come to was that Mr. Briggs had given them a
device that required probably more skilful handling,
but this could be acquired, and the more accurate and
better results got would well repay the trouble taken.
Firemen must in future be given every chance to do
their work with the most scientific devices obtainable,
and the loop might safely be included on the list of
such.

Mr. Wm. Walker, H.M. inspector of mines,
Edinburgh, said he thought there was something to
be said for this device, chiefly because of the fact that
they could detect with it the presence of gas in smaller
percentages sooner than could be done with the lowered
flame. His suggestion was that the committee of the
institute who had already tested with the loop should
be continued in office, and that further trials should be
made by practical firemen and colliery managers.

Prof. Burns, Glasgow, said the committee of which he
was convener, had come to the conclusion that the
naked flame without the loop was better as a gas
testing device than the loop itself. He still adhered to
that opinion notwithstanding what Mr. J. Balfour
Sneddon had said with regard to the recent tests at
Valleyfield and Bothwell Castle collieries.

Mr. W. Loudon, H.M. inspector of mines, said that
two months ago he had carried out extensive tests with
this device. He could see caps with the loop that he
had not been able to distinguish at all with the Wolf
lamp, and when a cap was discernible with the Wolf
lamp he could see a much bigger one with the Briggs’
device.

Mr. Jarvie (Messrs. Wm. Baird and Co.) said that as
a member of the committee appointed by the Institute
to make investigations into the matter, he felt that the
loop did not offer in the mine any advantage over the
lowered flame so far as practical utility was concerned.

Mr. H. J. Humphrys, H.M. inspector of mines,
remarked that the tests which he was presently con-
ducting showed that the cap seen by the loop was not so
dense as the cap got by the open flame.

Mr. Henry Rowan (Fife Coal Company) said he had
been invited to see the tests which had been made at
Valleyfield Colliery. He had to admit, speaking for
himself, that it would take him some time before he
would be able to detect gas as well with the loop as with
the ordinary lamp, to the use of which he had now got
accustomed. The flame of a cap as shown by the loop
was not anything like so dense as it was when an
ordinary lamp was used. Personally he favoured the
idea of continuing the tests.

Mr. Henry Briggs, in replying to the discussion,
said he had advanced certain claims in regard to the
utility of the loop in blackdamp testing, yet the report
by the committee of the institute made no mention of
blackdamp, and hence he concluded they made no tests
on that mixture. Although the loop as an indicator of
blackdamp was only a rough device, it possessed, he
thought, some claim to attention, as being the only
means at present known of enabling an estimation of
that impurity to be made with a safety lamp. The gist
of the report by the committee, it would be remembered,
was to the effect that gas was indicated by the lowered
flame sooner than by the loop. This could be denied at
once and without qualification, but it certainly was true
that a cap was shown by the lowered spirit flame before
it was shown by the loop. As a matter of fact, the
lowered spirit flame gave a cap in fresh air. He
thought it would be interesting to learn from any of
the members of the committee if the lowered flame was
examined in fresh air in their presence in order that they
might become familiarised with the fuel cap.

It was remitted to the council of the Institute to
arrange for the appointment of a committee to carry
out further experiments with the loop.

Underground Fires.

The meeting thereafter proceeded to discuss the
paper by Mr. Henry Rowan (Fife Coal Company) on
“ Underground Fires.”

Mr. R. W. Dron, Glasgow, in the course of a written
communication, said he agreed with the author’s sug-
gestion that the hydraulic stowing of the gob would
prevent gob fires. With hydraulic stowing there was

little or no crushing of the roof, and there was no
percolation of air through the waste. Indeed, it might
not even be necessary to fill up the whole of the waste
with water-borne material if some stowage could be
obtained more economically underground.

Mr. Wm. Smith, Dalmellington Ironworks, Ayr, said
he agreed that serious gob-fires were not confined, as
Dr. Harger said, to “ hot mines,” but might be found in
mines with a temperature not exceeding that at the
surface. In the course of his paper Mr. Rowan stated
that there was no record of fire when working the
Lochgelly Parrott, or lower portion of the seam, but
only when the splint or upper portion was being worked
back. That was exactly his (Mr. Smith’s) experience in
working the threefold longwall. It would be interesting
if the Commission could have placed alongside each
other sections of the various coalseams in the kingdom
liable to spontaneous combustion, with sections also of
their roof and pavement. They could also show a
tabulated analyses of these seams with their accom-
panying beds of fireclay and shale, or whatever portion
of the strata is suspected of causing heating.

Mr. William Walker, H.M. inspector of mines,
said that in France hydraulic storing had been found
useful, not only from the standpoint in which it was
discussed in the paper by Mr. Rowan, but also from the
point of view of obtaining every available ounce of coal.
Mr. Dron, at his pit in Wishaw had introduced hydraulic
stowing, with very successful results. Of course, he
(Mr. Walker) could not speak on the question of costs,
and he should be glad indeed if Mr. Dron would oblige
with some information on that point.

Further discussion on the paper was adjourned till
next meeting.

The Testing of Fans

Discussion was thereafter resumed on the paper by
Mr. John Watson on “The Testing of Fans: A Plea for
Standardised Tet-t Conditions.”

Mr. John M. Trusty (Nuneaton) in the course of a
written communication, said he was in general agreement
with the author as to the need for standard conditions of
fan-testing and, also for the authoritative definition of
terms brought into the problem. The term “ manometric
efficiency ” often figured largely in the claims made for
particular fans. There was no exact definition of its
meaning. It was defined in several ways in mining
literature and a useful purpose would be served if either
a definite meaning were given to the term or its abolition
suggested.

Mr. Wm. Smith, Dalmellington Iron Works, Ayr,
observed that the varying opinions of experts showed
how much the standardisation of fan tests was required,
and they were therefore indebted to the author for
placing before them the result of his varied experience.

Mr. James Black, Shettleston, said it was only when
describing the effect produced by a natural ventilating
force on fan ventilation that he differed with the author
in his treatment of the subject. In the main he was
in general agreement with the conclusions made by
Mr. Watson.

It was agreed to adjourn the discussion on this paper
till next meeting.

THE NATIONAL PHYSICAL LABORATORY.

The annual report on the National Physical Labo-
ratory contains a statement of the work proposed for
the year 1913. Amongst the investigations to be carried
out are the following :—

A determination of the mechanical equivalent of heat j at
present the values given for the equivalent when obtained
by electrical methods differ by 1 part in 1,000 from the
values obtained by mechanical methods.

The illumination of factories and workshops.

A specification for Tungsten filament lamps.

The measurement of alternating current power.

Research on buried cables.

The thermal conductivities of heat insulators.

The softening points of firebricks.

Wind pressure on structures.

The resistance of different forms of screw threads to
fracture.

Research on methods of impact testing.

Research on the light alloys of aluminium.

Effect of strain on steel at high temperatures.

Intercrystalline cohesion in metals.

The melting point of iron.

Many of these investigations are continued from
previous years. In regard to these and other branches
of research now completed, much valuable information
is given in the report.

The King of the Belgians has conferred upon Chevalier
J. J. Sutherland, the well-known Middlesbrough iron
merchant and shipowner, the honour of the gold medal
(first-class civil), in recognition of his services as consul for
Belgium at the port of Middlesbrough.