Tijly 31, 1914.

THE COLLIERY GUARDIAN.

251

The enormous strength of this arch may be realised
by comparing the smaller span, greater rise, and
increased thicknesses of the arch with that shown in
fig. 11.

The relative strengths depend largely on the amount
of reinforcing steel; but, generally speaking, ferro-con-
crete arches of equal strength to brickwork need be
about one-quarter to one-sixth the thickness. This
strength is derived mainly from the absence of joints,
and also from the fact that little steel is needed to
reinforce the concrete in tension in order to make it
equally strong in tension and compression.

It cannot be denied, however, that from time to time
objections have been advanced to the use of ferro-
concrete underground, and although there is some
ground for the objections, it is to be feared that
prejudice is also a factor which enters largely into the
objections :—

(1)	That the placing of a large number of small bars
accurately in position and keeping them there
during concreting is practically impossible under-
ground.

(2)	That the squeeze may come on before the concrete
has had time to set, so that the concrete would
easily crush and the bars all get displaced.

(3)	That the squeezes are so enormous that nothing
can be made to withstand them, so that something
is required which can easily be replaced.

(4)	That the supporting,, timbering and shuttering
would have to be in position for a month, during
which time it would block up the roadway.

(5)	That in wet places the cement would get washed
out of the concrete, etc.

The author has given these objections consideration
for some time, and has evolved a system whereby these

Fig. 14.

The mottled portion represents concrete packing.

Fig. 15.

The mo tied portion represents concrete packing.

objections can be overcome, and in time it is hoped to
give the results of the trials. However, dealing with
objection No. 3, if it is argued that nothing can stand
the squeeze, then this point is seriously contested. To
put up an admittedly weak construction on the ground
that it can be asily replaced, is rather damaging,, as
it is obvious that it can also easily fail. If some kind
of arching is made of this material, self-contained or
a closed figure, and if any movement took place, it could
move bodily without assuming any distorted or dis-
jointed shape. If surrounded in ashes it would be free
to move, but it is suggested that hard packing in the
nature of concrete or a method of grouting cement
under pressure is better, and the excavation shall be
taken out very sparingly.

In the case of a four-centre arch, as shown in fig. 8,.
the abutments or skew-backs would not be necessary,
and it would be possible to have vertical sides with
segmental roof and invert. In fact the range of
sections would be large, and the combination of beams
and arches monolithically connected would make both
a strong and effective whole.

Its ability to resist distortion is the key of its strength,
and as it has been shown that distortion is the principle
cause of masonry and brick arches failing, then it
remains to give ferro-concrete arches a trial, as in
addition they have other advantages to offer. In the
event of settlement or explosion, the arching would
resist forces applied from the inside equally with those
from the outside. Coal dust would have little lodgment,
as the inner face would present a clean and even bore,
which would also assist ventilation.

No doubt the question of expense will be raised.
There is every reason to believe that ferro-concrete

arches will be economical, as stone is readily available
for the concrete, and the finer grits may in most
instances, if the stone be suitable, be used instead of
sand. It is not suggested that a thin lining of ferro-
concrete is going to solve this arching problem under
all conditions; but there can be little doubt that, given
a fair trial, its great strength will go a long way to
replace the present methods and materials for arching,
so that with a little experience the author ventures to
predict that the failure of arches will be the exception
rather than the rule.

THE PUBLICATION OF REGULATIONS
AND ORDERS.

Mr. T. A. Southern, of the Universal Mining School,
Cardiff, sends us a copy of the following letter, which
he has sent to the Home Office :—

[copy.]

The Under-Secretary of State,

Horne Office, London, S.W.

Sir,—Will you kindly furnish me with a complete list of
all special Acts of Parliament, and of all Regulations,
Statutory Rules and Orders, and Regulations (if any) under
any other name, which apply to coal mines, and are at
present in force or have been settled and will shortly come
into force.

If you are unable to send me such a list, can you tell me
from what source I can obtain one? Also what steps a
colliery manager can take to assure himself of receiving
prompt notification from time to time of every alteration in
the Regulations, Orders, etc.

At present, colliery managers are in a state of hopeless
bewilderment and uncertainty, not knowing from day to
day whether the Regulations they are complying with are
still in Jorce, or whether there are further and later Regula-
tions that they have not heard of or have overlooked.

May I be allowed to suggest that, in order to ameliorate
this state of things, it would be well for the Home Office to
determine that in future no alterations in the Regulations,
Orders, etc., except in matters of extreme urgency, shall be
made except on one particular day of the year, e.g., January
1. That is to say, that all changes agreed upon during the
period of 12 months should be published collectively on that
particular date, and as far as possible there should be
uniformity in regard to the dates on which deferred Regu-
lations shall come into force. For example, all changes of
a simple character, not involving new apparatus or altera-
tions of existing appliances, shall come into force simul-
taneously one month after publication, and that, for the sake
of uniformity and simplicity, any new Regulation that
requires new appliances or alteration of existing appliances
shall be deferred to come into operation after a period which
in all cases shall be an exact multiple of three months from
the date of publication.

As an example of the bewilderment and uncertainty above-
mentioned, I have picked up a copy of the General Regu-
lations, dated July 10, 1913, contained in Statutory Rules
and Orders, 1913, No. 748. I refer to Regulation No. 92,
containing a code of signals for winding, and I read in
Regulation 97 that these signals were to come into opera-
tion on July 1, 1914, but I understand that during the last
few months this code of signals has been condemned as
dangerous, and that a new code has been or will
be substituted, but whether it has been, or when it will be,
I do not know, and should like to know.

In like manner, I have an impression that General Regu-
lations 138 to 149 inclusive, relating to rescue and
ambulance, have been, or are about to be, entirely revised,
but whether they have been, or when they will be, I do not
know, and should like to know.

It used to be that no change was made in the Regulations
until it had first been fully considered and agreed upon by
the parties concerned ; and that practice was doubtless a
good one, as being conducive to safety, good discipline, and
strict compliance with the Regulations, besides reducing to
a minimum the aggregate of individual trouble, loss of time,
and temporary disorder and dislocation of normal routine.
But in recent years a practice seems to have been adopted
of enacting Regulations and changes before they have been
considered and agreed upon by the various interests
concerned.

This has led to frequent “ alterations of alterations,”
resulting in an immense aggregate of waste, confusion, and
irritation ; the very antithesis of that simplicity and clear-
ness of the law and that cordial co-operation and agree-
ment, and respect for the law, which are so desirable for the
sake of smooth working and to avoid continual friction.

It would be a welcome relief to everyone concerned if it
were known that changes in the Regulations will not in
future be made before being thoroughly discussed, and,
failing agreement, settled by arbitration; and that no change
will be made except on a fixed annual date, as above sug-
gested ; instead of, as now, being liable to be sprung upon
us any day all the year round.—Yours faithfully.

T. A. Southern.

Investigation, says the Railway Gazette, shows that
from 15 to 25 per cent, of the total coal used by locomotives
is consumed in running sheds and elsewhere whilst the
engines are not actually performing service. Tests have
shown that from 20 to 35 per cent, of all the fuel on loco-
motives is burnt while the engines are stationary or not
actually engaged in hauling trains, and in a few cases the
absolute waste of fuel is as high as 50 per cent., whilst
examination of the ash pits has proved that from 35 to
50 per cent, of fixed carbon exists in the ash deposited
there. This matter was discussed at some length recently
at a meeting of an engineering society attended by a
number of railway locomotive men, and in the course of the
discussion it was pointed out that if the necessity for
cleaning fires so frequently was removed there would be a
saving in fuel, and an instance was given in which a saving
of <£205 had been effected by running the same engine
through over a distance of 240 miles instead of changing
en ro te. The question of firing up was also dealt with on
the same basis, and special attention was called to the
necessity of leaving ashpans open when fires were being
built up so that the coal falling through the grate would
fall into the pit and not clinker up the ash pan opening.

THE NEW SULPHATE OF AMMONIA
MANUFACTURERS’ ASSOCIATION.

At the annual meeting of the Sulphate of Ammonia
Committee it was agreed that the committee should be
amalgamated with the Sulphate of Ammonia Manufacturers’
Association, recently formed, under the title of the Sulphate
of Ammonia Association, with two sections, the one to
carry on propaganda work, which has hitherto been the
sole work of the Sulphate of Ammonia Committee, and the
other to attend to the sale of sulphate. Already makers
of sulphate, representing over 200,000 tons per annum, have
joined the sales section. It is estimated that an annual
contribution of 9d. per ton will cover the propaganda work,
and 6d. per ton‘the work of the selling branch of the
Association. Owing to continued ill-health, Mr. Thomas
Milne, who has acted as deputy chairman of the committee,
and chairman for the past ten years, has resigned. Mr. D.
Milne Watson, general manager of the Gas Light and Coke
Company, has taken his place. As a consequence, the offices
of the association are being moved to 84-86, Horseferry-road,
Westminster, S.W. At the request of the Scottish sub-
scribers a separate propaganda office, under the direction of
the Scottish members of the executive committee, with
Mr. William Love, of the Broxburn Oil Company, as
convener, has been established at 28, Royal Exchange-
square, Glasgow, with Mr. J.. D. Young as manager, and
all propaganda work in Scotland is now dealt with by the
Scottish office.

During the year 29 new subscribers joined the committee,
representing 19,500 tons of sulphate. The total number of
subscribers to the Committee is now 446, representing a
total of 303,924 tons of sulphate, an increase over last year
of 31,033 tons, being 19,500 tons from new subscribers, as
above, and nearly 12,000 tons increase in output from old
subscribers. The new subscribers include nine coal and
iron firms, with an output of 17,500 tons of sulphate.

For carrying on the work of the Selling Committee of
the new Association, the country has been divided into five
districts : (1) Scotland, which as a district is the largest
contributor of production; (2) Newcastle and district;
(3) Manchester district and Wales; (4) the Birmingham
and Midlands district; and (5) London and the South of
England. The committee already represent 210,000 tons
of the 430,000 tons of sulphate equivalent now produced in
this country. The Propaganda Committee—i.e., the old
Sulphate of Ammonia Committee—represent a production
of 304,000 tons.

The constitutions of the committees for the current year
are as follow :—

Propaganda Committee.

Mr. D. Milne Watson (chairman).

Mr. J. Blumer, Messrs. Bolckow, Vaughah and Co. Ltd.,
Middlesbrough.

Messrs. Brunner, Mond and Co. Ltd., Northwich.

Mr. Isaac Carr, Widnes Corporation Gas Dept.

Mr. F. T. Cotton, Alliance and Dublin Consumers’ Gas Co.

Mr. R. Dempster, Langloan Iron and Chemical Co. Ltd.,
Glasgow.

Mr. Wm. Dunsmore, Messrs. Wm. Baird and Co. Ltd.,
Glasgow.

Mr. Wm. Fraser, Pumpherston Oil Co. Ltd., Glasgow.

Mr. J. Fyfe, Young’s Paraffin Light and Mineral Oil
Co. Ltd., Glasgow.

Mr. R. F. Gloag, Messrs. Sadler & Co. Ltd., Middlesbro’.
Mr. E. A. Harman, Huddersfield Corporation Gas Dept.
Mr. W. R. Herring, Edinburgh and Leith Corporations’
Gas Depts.

Mr. R. S. Hilton, Birmingham Corporation Gas Dept.

Coun. W. Kay, J.P., Manchester Corporation Gas Dept.

Mr. Wm. Love, Broxburn Oil Co. Ltd., Glasgow.

Mr. F. J. Mason, Birchenwood Colliery Co. Ltd., Stoke-
on-Trent.

Mr. Thomas Milne, Gas Light and Coke Co.

Mr. G. C. Parnaby, South Metropolitan Gas Co.

Mr. James Paterson, Cheltenham Gas Co.

Mr. Lloyd Pease and Mr. J. M. Horsley, of Messrs. Pease
and Partners Ltd., Darlington.

Mr. R. G. Perry, Messrs. Chance and Hunt Ltd., Oldbury.
Aid. F. S. Phillips, J.P., Salford Corporation Gas Dept.
Mr. H. Pooley, Leicester Corporation Gas Dept.

Mr. A. Stanley, Simon-Carves By-Product Coke Oven Con-
struction and Working Co. Ltd., Manchester.

Mr. R. M. Sutherland, Messrs. J. Ross and Co., Falkirk.

Mr. Hanbury Thomas, Sheffield United Gas Light Co.

Mr. T. Waddom, Newcastle-on-Tvne and Gateshead Gas
Co.

Mr. P. Ward, Bradford Corporation Gas Dept.

Mr. J. Wishart. Oakbank Oil Co. Ltd.. Glasgow.

Selling Committee.

No 1 district (Scotland)—

Mr. W. Fraser. Pumpherston Oil Co. Ltd.

Mr. J. Fvfe. Young’s Paraffin Light and Mineral Oil
Co. Ltd:

Mr. W. Love. Broxburn Oil Co. Ltd.

No 2 (Newcastle District)—

Mr. J. Blumer, Bolckow, Vaughan and Co. Ltd.

Mr. W. J. D. Burnyeat, Cumberland Coal Owners’ Asso.

Mr. T Waddom. Newcastle-on-Tvne and Gateshead Gas
Co.

No. 3 (Manchester District)—

Aid. F. S. Phillips. Salford Corporation Gas Dept.

Mr. A. Stanley. Simon-Carves By-Product and Coke Oven
Construction and Working Co. Ltd.

Mr. R. Jones, Yorkshire Semet-Solvay Co. Ltd.

No. 4 (Birmingham District)—

Mr. R. S. Hilton, Birmingham Corporation Gas Dept.

Co]. Jackson. Clay Cross Colliery Co. Ltd.

Mr. E. Mond. South Staffordshire Mond Gas Co.

No. 5 (London and Southern District)—

Mr. G. C. Parnabv, South Metropolitan Gas Co.

Mr. T. Milne, The Gas Light and Coke Co.

Mr. J. R. Jacobs, Southampton Gas Light and Coke Co.