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International Engineering Congress (1901 : Glasgow.

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immediate production of this flame is caused by carbonaceous
matter in the lining of the vessel ; that its luminosity is due partly
to the volatilisation of the alkalies, and to the incandescence of
lime dust carried out by the blast.

Secondly, volatilisation of metal occurs largely at an early period
in the blow, and is due to the difference in composition of the metal
blown, chiefly to the smaller quantity of silicon. There is practi-
cally no distinct period when siliceous slags are formed in the
" basic " process, and metals are volatilised readily in the reducing
atmosphere, rich in carbon monoxide.

Thirdly, a very large amount of fume is formed towards the close
of the second period. This arises from the oxidation of metal
and of phosphorus in the iron phosphide being productive of a
high temperature, but little or no carbon remaining. The flame
is comparatively short, and the metallic vapours carried up are
burnt by the blast.

Fourthly, the " over-blow " is characterised by a very powerful
illumination from what appears to be a brilliant yellow flame; a
dense fume is produced at this time, composed of oxidised metallic
vapours, chiefly iron. These particles are undoubtedly of very
minute dimensions, as is proved by the fact that they scatter the
light which falls on them, and the cloud casts a brown shadow, and,
on a still day, ascends to a great height. The spectrum is con-
tinuous, but does not extend beyond wave-length 4000. This
indicates that the source of light is at a comparatively low-
temperature, approaching that of a yellowish-white heat. Con-
sequently, the light emanates from a torrent of very small particles,
liquid or solid, at a yellowish-white heat. The flame can have but
little reducing power at this stage, and this, together with its low
temperature, accounts for the very feeble lines of lithium, sodium,
potassium, and manganese seen in the photographs or by eye
observations.

Fifthly, the spectra of flames from the first stage of the basic
process differ from those of the acid process in several particulars.
The manganese bands are relatively feeble, and lines of elements,
not usually associated with Bessemer metal, are present. Both the
charges of metal and of basic material contribute to these.
Lithium, sodium, potassium, rubidium, and caesium have been
traced mainly to the lime; manganese, copper, silver, and gallium
to the metal. Other metals, such as vanadium and titanium, are
not in evidence, because they do not yield flame spectra; they,
together with chromium, pass into the slag in an oxidised state.



AN INVESTIGATION OF THE SPECTRA OF FLAMES. 207

2. Differences in the Intensity of Metallic Lines. The intensity
of the lines of any metal varies with the amount of the metal in
the charge, but in some cases variations of intensity occur among
the lines of orie metal, as observed in the spectra photographed at
Crewe in 1893; especially is this the case with some lines in the
visible spectrum of iron. These variations are due to changes in
temperature ; as the temperature of the flame rises, some lines fade
almost away, others bedbme stronger. Such changes are more
marked in the arc spectrum, and still more in the spark spectrum of
iroa. Lines of potassium and the edges of manganese bands are
shown to have been intensified by the proximity of iron lines in
some cases, but this is doubtless a result of low dispersion. The
two violet rubidium lines nearly coincide with two lines of iron.

3. A nciv line of Potassium with Variable Intensity. -This line,
wave-length approximately 4642, varies in intensity within some-
what wide limits. In a given flame its brilliancy is increased by
diminishing the quantity of metallic vapour in the flame; this does
not appear to depend altogether on the weakening of the con-
tinuous spectrum which accompanies the line spectrum of
potassium; the experiments made with various salts of potassium
show that it is probably due, in part at least, to the increased
freedom of motion permitted to the molecules of the metal.



The paper was taken as read.

A vote of thanks was accorded to the authors.



BRINELL'S METHOD OF DETERMINING HARDNESS
AND OTHER PROPERTIES OF IRON AND STEEL."

PART II.

Paper by AXEL WAHLBERG.



Abstract.

IN the Swedish section of the metallurgical department at the
Paris Exhibition were displayed in systematic arrangement some
results of experiments and methods of procedure relating to the
testing of material, which attracted special attention. The experi-
ments were conducted by Mr. J. A. Brinell, and the expense was
borne by the Fagersta Works. They resulted in the development
of a new and original method for determining the hardness and, to
a certain extent, the tensile and ductile properties of iron and steel.
The method alluded to is to be fully worked out on the initiative
of the " Jernkontoret," which has granted ample funds for the
purpose of carrying out further investigations on an extensive scale
in the laboratory for testing materials at the Royal Technical High
School at Stockholm. Among the most important questions to
be decided by these experiments is that of ascertaining the practical
utility of this method for determining the tensile properties of any
kind of iron or steel material. For the purpose of comparison the
experiments will be made with various qualities of both Swedish
and foreign steel, the former being obtained from six or seven
different works in Sweden. Mr. Wahlberg's paper gives an account
of the results already achieved by Brinell. Among the more
comprehensive researches described is a very complete series of
results dealing with hardness, determined on steel specimens repre-
senting 1500 different charges of acid open-hearth steel, of a widely
varying chemical composition. Many of the experiments were
intended especially to illustrate the influence of annealing and
hardening, and these probably form the most extensive series of
experiments that has ever been attempted for this purpose. In
carrying out the tensile tests Brinell made use of thirteen different
kinds of steel, of varying composition, each of which had been
subjected to no less than 31 different modes of treatment. In a
second series, which was carried out for the purpose of ascertaining
what impact stress the material could withstand, the same 13 kinds
together with two more, were used, each kind in this case having
been treated in ten different ways. Lastly, his researches on the



DETERMINING HARDNESS OF IRON AND STEEL. 209

formation of blow-holes in ingots deserve notice. The results in
this instance were obtained by testing 871 different charges, without
taking any account of the innumerable experiments extending over
several years, which Brinell made preparatory to drawing up his
programme on the definite lines by which the later results were
obtained. The first part of the paper was published in the
"Journal of the Iron and Steel Institute" (1901, No. I., pp. 243
to 298), and the present ^>aper, covering forty pages, and illustrated
by numerous plates, completes the work. Mr. Wahlberg expresses
his regret that Mr. Brinell has been unable to find time to prepare
a paper describing his own labours and their results.



The paper was taken as read.

A vote of thanks was accorded to the author.



" THE INTERNAL STRAINS OF IRON AND STEEL AND
THEIR BEAPvING UPON FRACTURE."

Paper by ARTHUR WINGHAM.



Abstract.

THE object of this paper is to assist the elucidation of some of the
mysteries attendant upon the physical behaviour of metals generally,
and of iron and steel in particular, and to throw light upon the
cause of the sudden and unexpected breakages of metal used for
machinery and other purposes. Its reasonings are based upon
the following facts and hypotheses : That there are two kinds of
equilibrium to which a metal attains, viz., chemical and physical;
that the natural tendency of a complex metal is to assume its most
simple forms of combination preferentially capable of existing at
a given temperature; that its rapidity of cooling, even under the
slowest conditions, is too great to allow this to reach finality; that
the equilibrium is further repeatedly interfered with by changes of
atmospheric and other conditions ; that the adjustment to physical
equilibrium tends to assist the adjustment to chemical equilibrium ;
that adjustment which is assisted by slightly raised temperatures,
also, as a consequence, takes place in the cold ; and that the
eutectic is the medium through which the chemical or molecular
change takes place, working, of course, in conjunction with the
vibration of the molecules. The subject is of both scientific
interest and of practical importance. It is of great practical
importance in the case of so-called permanent structures, especially
where those structures are heavy and subjected to vibration or to
shock. In such cases the greatest change or depreciation will
take place at the points of jarring contact. Consequently, a strong
and tough structural steel, well within the mechanical limits of
the specification to-day, may, in the course of a few years, develop
some of the properties more generally associated with cast iron.
The latest instance of this is the recent mishap to the Brooklyn
Bridge. The trouble appears to have been caused by the fracture
of the vertical suspension rods holding the traffic way to the cables.
The rods, no doubt, had a plentiful margin of original strength to
cover any excessive or heavy usage, and it is hardly likely that the
fractures were caused by extra traffic alone. It is more probable
that the repeated vibration and the release of internal pressure by



THE INTERNAL STRAINS OF IRON AND STEEL. 211

the persistent tensile strain have accelerated an excessive tendency
of the metal to crystallise, and so reduced its tensile strength.
Other suspension rods in the same structure are probably approach-
ing the same end. Obviously the internal stability of modern
structural steel is worthy of serious consideration, when the selection
of the best metal in view of longevity might prevent the com-
paratively early breakdown of an important structure.



The paper was taken as read.

Written contributions to the Discussion were received from Mr.
J. E. Stead and Mr. Walter Rosenhain.

The author replied.

The following votes of thanks were then proposed by the
Chairman :

To the University Court for their kindness in granting the use
of the Lecture Hall for the purposes of the meeting; to the Chair-
man, Mr. William Beardmore; to the Vice-President, Mr. Archibald
Colville ; to the Honorary Secretary, Mr. James G. Jenkins ; to the
members of the Local Reception Committee for the arrangement
they had made; to the proprietors and managers of the various
works for the permission given to visit their establishments; to the
Railway Companies; and to the committees of the various Clubs
who had accorded privileges to the members.

Sir David Dale, Bart., seconded.

Mr. George Beard proposed a vote of thanks to the Chairman, and
Mr. E. J. Ljunberg seconded.

The Chairman acknowledged briefly, and Proceedings of the
.Section terminated.



SUMMARY OF PROCEEDINGS

OF

Section VI. Mining.*

TUESDAY, 3rd SEPTEMBER, 19d.

Sir WILLIAM THOMAS LEWIS, Bart., in the Chair.



PRESIDENTIAL ADDRESS.

By Sir WILLIAM THOMAS LEWIS, Bart.,
Retiring President of the Institution of Mining Engineers.



EXTRACTS.

" IT is pleasant to be able to congratulate all those connected with
coal-mining as to the continued satisfactory condition of the coal
trade, and it is especially gratifying for me to record the continuation
of what has been referred to in detail by some of my predecessors
respecting the reduced risk in the conduct of coal-mining operations,
which recent statistics show to have been reduced to less than one-
fourth of what it was per 1,000,000 tons raised when I first entered
the profession 50 years ago, the death rate being 4 lives per
1,000,000 tons of coal raised in 1900 as against 19 persons killed
per 1,000,000 tons raised in 1851. This increased safety, as you
are aware, has been brought about gradually by the introduction of
machinery, by improved discipline and better management; and
from time to time Acts of Parliament have been passed which were
based upon the accumulated experience of those connected with
mining throughout the kingdom; but with all the improvements
in mechanical appliances and in ventilation, as well as in the various
protective arrangements carried out daily, I may say hourly, by the
army of officials connected with collieries all over the kingdom,
coal-mining is still, unfortunately, attended with risk, although the
occupation as a whole ranks as particularly healthy as compared
with other trades. The cause of almost one half of the accidents
in coal-mines, that is, falls of roofs and sides, has of late had special

* The full Proceedings of Section VI., being part of Volume XXII., 1901,
of the Transactions of the Institution of Mining Engineers, are published
by the Institution of Mining Engineers, Neville Hall, Newcastle-upon-Tyne,
price i is. post free.



PRESIDENTIAL ADDRESS. 213

attention, and I look forward with confidence to a reduction in the
number of such accidents in the districts where bad roofs prevail
by additional care on the part of the miners in propping and tim-
bering, and also by an extension of the use of improved lights for
the workmen."

" Those who have means of reference will find that in addition
to the greater immunity from accidents our miners now also enjoy
much better pay for the* same amount of work ; so that, on the
average comparing present operations with those of a similar kind
40 years ago, there has been a permanent increase in the labour
cost of coal-getting of at least 20 per cent. leaving entirely out
of the calculation the recent prosperous times in the coal trade."

" Of our total coal-output no less than 58,405.000 tons were
exported, being 3,000,000 tons higher than any previous year's
coal - export the following being our principal customers :
France, 7,541,000 tons; Germany, 6,099,000 tons; Italy, 4,947,000
tons; Sweden, 3,035,000 tons; Belgium, 1,213,000 tons: Russia,
2,000,000 tons; and Spain, 1,500,000 tons.

The United States coal-export in 1900 amounted to 7,551,850
tons, which was double their coal-exports in 1897; and as a large
number of new collieries have been recently opened and equipped
with the best mechanical appliances, it is fully expected in order
to keep the mines regularly at work there will be a further increased
output in the States, which will be thrown on the export markets."

" In connection with the preservation of our export trade it must
not be forgotten how greatly the nation benefits through the number
of steamers employed in carrying the export coal ; and by reason
of many of the steamers thereby securing a round trip our manu-
facturers and others depending on imports are enabled to secure
their supplies at much lower rates of freight than would otherwise
have been possible.

Some of my predecessors in this chair have dwelt upon the
important matter of the duration of our coal-resources, which has
recently again been the subject of discussion. Of course the dura-
tion of our minerals depends first of all upon the probable yield
of useful fuel from our several coal-fields, and next what our annual
requirements, including exports, are likely to be in the future. So
far I have been unable to discover, in the various calculations made
as to the quantity of useful coal remaining in our coal-fields, to
what extent it has been assumed the present wasteful mode of
working in some of the fields may continue to be modified ; and,
on the other hand, whether the present wasteful mode of using coal
in our steam engines and our manufactures is also assumed to con-
tinue. The modification of either of which would of course make
a very material difference in the number of years that our usable
coal will last.



214 PRESIDENTIAL ADDRESS.

With every desire to avoid anticipating the enquiry which has
been indicated probable by a Royal Commission, and without
attempting to follow the various eminent geologists and engineers,
who have recently dealt with this subject, into their calculations
as to the number of millions of tons of coal remaining unworked
in the United Kingdom, which will, I have no doubt, be carefully
gone into if the proposed commission is appointed, I think it useful
tto direct your special attention to some important points bearing
upon the question of our mineral resources, namely :

(1) The enormous waste there has been in the past, and con-
tinues at present in many places, in the working of the various
seams of coal.

(2) The loss through such a number of seams of coal being left
in the ground, owing to their quality, their thinness, or their
proximity to more valuable seams, and their being depreciated by
the working of the more valuable seams.

(3) The custom which prevails in many districts of lessees work-
ing out only the best or more profitable seams, without regard
to the effect upon the thinner, inferior, or more expensive seams
under the same properties ; and also the loss through such great
quantities of small coal being made in working, and the proportion
of small coal left underground in many districts."

" With respect to seams left unworked through their thinness
or their proximity to more valuable coal-seams, it is gratifying to
jrecord the very great change that has taken place throughout the
kingdom, especially since the introduction of the long-wall system,
as to the thickness of what is regarded as a workable seam of
coal. I find from a paper read by the late Mr. G. C. Green well
on the working of thin seams of coal by longwall and bord-and-pillar
about 35 years ago, that in the more highly favoured coal-districts
of the country seams of 2\ feet, or even more than that thickness,
were at that time considered unworkable to a profit, and conse-
quently left in the mine untouched ; and Mr. Greenwell further
stated that in the Newcastle Coalmeasures there were no fewer
than 15 seams of coal under 2 feet 6 inches in thickness which
were all considered unworkable, while at the same time in collieries
under his management in the neighbourhood of Bath 3 seams were
worked varying from 12 to 16 inches thick, and 4 seams varying
from 2 feet to 2 feet 4 inches thick."

" With reference to the number of tons of coal unworked in our
different coal-fields it is of course easy to calculate from the plans
and sections of the seams proved, making the usual allowances for
faults and loss in working ; but, as I have endeavoured to indicate,
the important question is, how many of the seams can be assumed
to be workable to profit from time to time, and how much of the
coal contained in the various seams can be usefully obtained. If



PRESIDENTIAL ADDRESS. 215

the thin seams cannot now be worked, while we have superior coals
in thick seams to mix with them, I fear that many of the thinner
and the inferior coal-seams are much less likely to be profitably
worked in the future, when they have to be worked in many cases
either above or below abandoned workings, which may have sub-
sided or be subject to water or any other causes, and when to some
extent they will require to be won by deeper and more expensive
collieries; the whole of which of course are elements of great
uncertainty.

So much on the question of waste and loss that, in my opinion,
can and should be modified so as to prolong our useful sources
of supply; and then comes the question of our requirements as a
nation, first for home consumption, and next for exportation and
the maintenance of our commercial position. As to our own re-
quirements there can be no doubt that great saving ought to, and
I hope will, be effected, if not immediately, most certainly when our
coal-output becomes more costly. It is of course dangerous to
prophesy, as has been instanced by the estimates of so many of
the eminent men who dealt with the subject in connection with
the Royal Coal Commission of 1871, which subsequently were found
inaccurate; but we may at all events reasonably assume that as
our fuel becomes more costly further attempts will be made to
continue improvements in the direction of realising a much nearer
approach to the theoretical value of our coal, and thus secure
further enormous economies.

" Were it not that our fuel had been so cheap until recent years
many of the economies which have been introduced from time
to time in our modern boilers, our best engines and manufacturing
machines, and operations of various kinds, instead of being con-
fined to modern works only would have been generally adopted
by all steam users and manufacturers, and thereby a great saving
of our fuel effected. With reference to a portion of this subject
I may be pardoned for calling attention to the contents of a most
valuable paper read at the last meeting of the Institution of
Mechanical Engineers, at Barrow, by Mr. James M'Kechnie,
wherein he sets forth the great improvements that have taken place
in the boilers and engines of steamers during the last 30 years by
improved boiler and heating arrangements, the adoption of higher
steam pressure, the compounding of engines, and increased piston
speed ; which has resulted in the average consumption of fuel in
steamers being reduced from 2.11 Ibs. per H.P. per hour in 1872
to 1.83 Ibs. per H.P. per hour in 1881, to 1.52 Ibs. per H.P. per
hour in 1891, and to 1.48 Ibs. per H.P. per hour in 1901.

It is hardly necessary to point out that such an apparently
small saving, if applied to all the boilers in the United Kingdom,



216 PRESIDENTIAL ADDRESS.

as well as the steamers sailing under the British flag, would
^represent millions of tons per annum ; and considering that even
with these economical results we are far from enjoying one half
of the economies which experts consider may still be made in the
use of coal for steam purposes, and that we may confidently expect
great advantages by the utilisation of inferior coals, by gas arrange-
ments such as Mr. Mond's and others', by the extension of the
utilisation of gas for manufacturing purposes, by the application
of gas for the generation of electric power for lighting and heating,
by the application of our water supply for the generation of
electric power, and also by the application of liquid fuel for various
purposes enormous savings of fuel could be secured which would
greatly reduce our consumption of coal. This, coupled with the
husbanding of our coal resources by a substantial reduction of the
waste I have previously referred to in the working of our coal-seams,
<would, in my opinion, extend the duration of our coal resources
so as to provide for all our requirements and maintain our com-
mercial position as a nation, while amply providing for the protection
of our country, for a much longer term of years than any of the
Decent estimates I have seen on the subject."



On the motion of Mr. H. C. Peake, seconded by Mr. J. A.
Longden, a vote of thanks was accorded to the Chairman for his
address.

Thereafter the Chairman introduced Mr. James S. Dixon, the
president of the Institution of Mining Engineers, who thereupon
took the Chair.

Mr. Dixon acknowledged the honour which had fallen to him in
being elected President of The Institution of Mining Engineers, In
the course of a short address, he remarked upon the absence in
Scotland of a centre for the teaching of the higher branches of the
science and practice of mining, and announced his intention of giving
a sum of ;i 0,000 for the endowment of a lectureship in mining in
the University of Glasgow. The Very Rev. Principal Story, on
behalf of the University, gratefully acknowledged the gift.



Mr. JAMES S. DIXON in the Chair.



"THE OIL SHALE FIELDS OF THE LOTHIANS."
Paper by H. M. CADELL.



Abstract.

5.

THE author first described generally the principal characteristics
of the Scottish carboniferous system of the Lothians, which in-
cluded the coal measures, millstone grit, carboniferous limestone,
asd lower carboniferous or calciferous sandstone series. The last
and lowest of these divisions contained in its upper section the oil
shale measures. The thickness of the calciferous sandstone series
he estimated in round figures at 9000 feet, and the oil shale
measures occupied the upper 3000 feet of this section. Oil shale
was not necessarily confined to this geological horizon, but in
Scotland all the oil was at present derived from seams comprised



Online LibraryInternational Engineering Congress (1901 : GlasgowReport of the proceedings and abstracts of the papers read → online text (page 19 of 37)