|
In the search for coal the
geologist has rendered valuable help to the engineer by placing at his
disposal scientific information as to the particular location of coal,
ironstone, and oil shale in any given area, and the probable strata to be
penetrated in the attempt to reach these minerals. To ascertain the actual
presence of the mineral and the thickness of the seam, boring is resorted
to, and for this purpose a variety of appliances, driven by steam power, are
used according to the nature of the strata and the depth to be bored. The
next operation is the sinking of the shaft. Before the invention of the
atmospheric engine by Newcomen in 1710 the depth of mine shafts was limited
by the difficulty of carrying off the water. Sixty fathoms was about the
greatest depth attainable in the United Kingdom, the diameter of the shaft
being at most between 7 and 8 feet. Since then this depth has been greatly
exceeded, and already in 1840 the shaft at Nitshill, Renfrewshire, had a
depth of 175 fathoms. By the Coal Mines Regulation Act of 1887 each mine
must in ordinary circumstances have at least two shafts, with which every
working seam must be connected and between which there must be a
communication of not less than 4 feet high by 4 feet wide. The shafts in
Scotland are usually rectangular, but in recent times the circular shaft has
been adopted, as at Niddrie Colliery, with a diameter of 17 feet. The
eliptical form is also in use in the Wemyss Collieries in Fifeshire. For
shaft making, implements and machinery of a very varied kind, according to
the nature and depth of the strata to be worked through, have been devised.
The shafts having been made,
main roads are constructed by blasting and drilling in the area to be
worked. Two methods of working the coal are in vogue—the bord (Saxon for
road) and pillar, and the long wall methods. The former, known by the local
name of " stoop and room," is that mainly in use in Scotland, and consists
in driving passages or "rooms" through the coal of from 12 to 20 feet wide,
leaving pillars or "stoops" of the coal, between 10 to 20 yards square to
support the roof of the passage. These pillars remain till the limit of the
seam is reached, and are then cut away, the miner working backwards and
using wood props to support the roof. By the long wall method the whole of
the coal is removed as the miner works inward and the passage maintained by
walling it with stone or waste. Modifications of both systems are also in
operation.
Ventilation is an essential
in order to dilute and remove the noxious gases in the mine and thus secure
as far as possible the safety of the miner. Fire damp was long considered to
be the main cause of explosion, but coal dust was ultimately found to be an
equally dangerous factor, as Mr Galloway showed in 1878, though it was only
in recent times that the subject was thoroughly investigated and convincing
proofs of the fact accumulated. To ventilate the mine the expedient of the
furnace was long in use, but this expedient has been largely superseded by
ventilating fans driven by steam or electricity. The invention of the safety
lamp by Sir Humphrey Davy in 1815 further contributed to the safe working of
the mine.
In the early days of coal
mining in Scotland, when the mines were comparatively shallow, the coal was
carried by bearers along the pit bottom and up the stairway in the shaft to
the pit mouth. In the mines in the eastern district these bearers were
generally women and even children of tender years, and the weight carried by
the women might high as several hundredweights. The physical and moral
effects of such toil, protracted over 15 or even 18 hours out of the 24,
were deplorably bad. Mechanical hoisting in cages drawn up the shaft by
windlasses driven by horse power, and later by steam winding engines,
ultimately superseded the primitive method of carrying the coal in buckets
up the wet and slippery stairway. It was still in vogue in the Lothian
coalfield in the beginning of the nineteenth century, and the laborious
operation is described by Mr R. Bald in his General Vieiv of the Coal Trade
of Scotland, published in 1808. "In these collieries, where this mode is in
practice, the collier leaves his house for the pit about 11 o'clock at night
(attended by his sons, if he has any sufficiently old) when the rest of
mankind are retiring to rest. Their first work is to prepare coals by hewing
them down from the walls. In about three hours after, his wife (attended by
her daughters, if she has any sufficiently grown) sets out for the pit,
having previously wrapped her infant child in a blanket and left it to the
care of an old woman, who, for a small gratuity, keeps three or four
children at a time, and also, in their mother's absence, feeds them on ale
or whisky mixed with water. The children who are a little more advanced are
left to the care of a neighbour; and under such treatment it is surprising
that they ever grow up or thrive. The mother having thus disposed of her
younger children, descends the pit with her older daughters, when each,
having a basket of suitable form, lays it down, and into it the large coals
are rolled; and such is the weight carried that it frequently takes two men
to lift the burden upon their backs; the girls are loaded according to their
strength. The mother sets out first, carrying a lighted candle in her teeth;
the girls follow, and in this manner they proceed to the pit bottom, and
with weary steps and slow ascend the stairs, halting occasionally to draw
breath, till they arrive at the hill or pit top, where the coals are laid
down for sale, and in this manner they go for 8 or 10 hours almost without
resting. It is no uncommon thing to see them, when ascending the pit,
weeping most bitterly from the excessive severity of the labour; but the
instant they have laid down their burden on the hill, they resume their
cheerfulness and return F down the pit singing. . . . The weight of roals
thus brought to the pit top by a woman in a day amounts to about 36 cwts.,
and there have been frequent instances of 2 tons being carried. The wages
paid them for this work are eightpence per day."
Even after the abolition of
this drudge system female and child labour was retained for transporting the
coal from the working to the bottom of the shaft, and the report presented
to Parliament in 1842 by the commissioners appointed at the instance of Lord
Ashley, afterwards Earl of Shaftesbury, revealed the shocking conditions
under which this labour was carried on. "In the East of Scotland," the
commissioners reported, "where the side roads do not exceed from 22 to 28
inches in height, the working places are sometimes 100 and 200 yards distant
from the main road; so that females have to crawl backwards and forwards
with their small carts in seams in many cases not exceeding 22 to 28 inches
in height. The whole of these places, it appears, are in a most deplorable
state of ventilation. The evidence of their sufferings, as given by the
young people and the old colliers themselves, is absolutely hideous."
The result was the Act of
1842, prohibiting the employment of boys under 10 years of age, limiting the
period of apprenticeship, and putting a stop to the employment of women.
The method of conveying the
coal underground by small baskets was displaced by the use of larger ones
shod with iron and dragged by men or horses. Still later these were
superseded by small railways, wheel carriages, and to a certain extent steam
haulage. Coal cutting machinery driven by compressed air is also in
operation in a number of collieries. Electricity for the purpose of
signalling and electric lights in the main roads are among other
improvements.
The main coalfields are
situated in the central counties and the largest output is still from those
of Lanark and Ayr. In recent years there has, however, been an extension of
the mining industry in the Lothians and Fife, and this extension eastwards
has been actuated by the necessity of finding new sources in view of the
steadily increasing demand and the possibility of the ultimate exhaustion of
existing fields. Industrial development is dependent on coal supply. As the
late Mr Stanley Jevons pointed out, "coal stands not beside, but entirely
above all other commodities. It is the material source of the energy of the
country—the universal aid—the factor in everything we do; without it we are
thrown back into the laborious poverty of early times." For the production
of iron and steel, for the generation of propulsive power on land and sea,
for the working of factories, for instance, coal is an essential requisite.
Britain's industrial greatness ultimately rests on its coal mines. Hence the
growth of the coal output with the growth of such enterprises. This growth
has, accordingly, steadily advanced during the nineteenth century, and from
about the middle of it it has been almost quadrupled, though the industry
has been subject to frequent strikes adversely affecting the output in the
years in which they have occurred. In 1854 it was nearly million tons; in
1880 it was fully 18½ millions; in 1900 it had risen to over 23 millions; in
1908 to fully 39 millions. Throughout this period Lanarkshire has held the
lead of the coal producing counties with more than half the whole tonnage,
its total in 1900 being over 17 millions. Fifeshire was second with about 5\
millions, Ayr third with fully 4 millions, Stirling fourth with nearly 2½
millions, Midlothian fifth with 1½ millions, and West Lothian sixth with fully
1 million, whilst Clackmannan, Dumbarton, and East Lothian were near or over
half a million, and Renfrew occupied the lowest place with about 13,000. In
1908 the proportion for Fife had risen to nearly 8½ millions, for Stirling
to nearly 3 millions, Midlothian to nearly 2½ millions, West Lothian to nearly
2 millions, East Lothian to over 1 million, and Renfrew to nearly 100,000.
The export of coal bulks
largely in Scottish export trade, of which by far the largest portion is
centred in the Firth of Forth. From the Fife ports alone upwards of 5
million tons were shipped in 1913, Methil leading the way with 3½ million
and taking first place as a coal shipping port in Scotland, Burntisland
being next with nearly millions. The total from the ports on the south side
of the Forth—Leith, Granton, Bo'ness, and Grangemouth —was considerably over
4½ millions. In 1911 the total shipments from Scotland to home and foreign
ports (including bunker coal) was 10½ millions.
Oil shale is now mined only
in Mid and West Lothian, though it is found in limited quantities in other
districts and was formerly worked on a large scale at Burntisland in
Fifeshire. Within the limited area mentioned it was also mined by the
Clippens Oil Company at Straiton and Burdiehouse, but owing to litigation
with the Edinburgh Water Trust, the Company was compelled to abandon
operations. In one or two places—at St Catherine's, Liberton, near
Edinburgh, and in the Broxburn district, for instance—natural oil in small
quantities has been found. But practically the crude oil has to be extracted
from the shale mined for the purpose, and in this respect the oil producing
industry in Scotland is carried on under difficulties and disadvantages
unknown in those more favoured regions of the world where the liquid is
obtained from the vast reservoirs in the bowels of the earth, as in the
oilfields of America, the Caspian, and Burma. "The Scottish oil," says Mr
Caddell, "in its dry matrix of black shale, has first to be laboriously
won—blasted out of mines hundreds of feet deep, hauled or hoisted by
machinery to the light of day and crunched into small pieces between strong
iron teeth, then carried perhaps some miles to the retorts, where it is
carefully distilled and separated from' its earthy casing—before it ever
reaches the condition of the crude petroleum that spouts up in other
countries ready made."
The oil shale is described by
the same authority as "a minutely laminated, or amorphous black, or dark
brown clay shale containing nitrogen, hydrocarbons, and other substances of
organic' origin derived from the macerated remains of plants and animals."
The oil producing material in the shale was named Kerogen by Professor Crum
Brown, and this substance is distilled into crude oil and refined into
paraffin and other products.
The father of the industry
was James Young, who was born in 1811, learned the trade of a cabinet maker
at Glasgow, and after attending the lectures in chemistry of Professor
Graham, became his assistant. Later he became assistant to the Professor of
Chemistry at University College, London, and chemist at Tennant's Chemical
Works, Manchester. Whilst occupying this latter post he was consulted by
Professor Lyon Playfair about a petroleum spring in a coal pit in
Derbyshire, where in 1848 he [erected works ior refining the petroleum and
where for a couple of years oils and paraffin were produced until the spring
was exhausted. Young rightly inferred that the oil was the result of the
natural distillation of coal and coaly substances, and in the course of his
experiments he discovered in 1850 at Boghead, near Bathgate, a seam of what
seemed to be cannel coal, but was in reality a rich kind of oil shale which
yielded 120 gallons or more of crude oil per ton. In the same year he took
out a patent for the production of paraffin from bituminous coal and in
partnership with Messrs Meldrum and Binney started distillation works near
Bathgate. Even before the expiry of Mr Young's patent in 1864 other works
began to spring up throughout the region at Broxburn, Uphall, Mid-Calder,
West Calder, Kirkliston, etc., and in 1865 Mr Young started new works at
Addiewell, near West Calder. The decade between 1860 and 1870, during which
the number of oil works increased from 6 to 90, was a period of rapid
expansion. After 1870 American competition began to tell adversely on the
Scottish industry, and later this competition was aggravated by the
exploitation of the oil fields of the Caspian, Galicia, Burma, and other
regions. In 1880 the number of Scottish works had decreased to 26, to 14 in
1890, and 9 in 1900, and now only 7 have survived in the struggle for
existence at Addiewell, Broxburn, Pumpherston, Oakbank, Dalmeny, Philipstown,
and Tarbrax.
The effect of this steadily
increasing competition was a lowering of the retail price of refined burning
oil from about 3s. 6d. during the period of Young's patent to 4½d. per
gallon in 1911. But for the other substances in addition to burning oil
contained in the shale, such as sulphate of ammonia, petrol, naphtha, tar,
and the improvement in the machinery and the processes of production, the
industry would ere now have been extinct.
Three million tons of shale
are mined per annum, showing a rise of a million tons in the first decade of
the twentieth century, producing 72 million gallons of crude oil, 75 per
cent, of which was refined into finished products, and over 50,000 tons of
sulphate of ammonia. "The advance in scientific technology," says Mr Cadell,
"has led to such additional economies in the processes of manufacture that
it is now possible, in spite of many adverse conditions, to work profitably
seams when used to be considered too poor to be of any commercial value.
Indeed sueh is the recent progress in the scientific construction of the
retorts that the shale is now made to distill itself with the heat derived
from its own residual combustible gases, and no fuel is required except in
the temporary process of starting new plant. The waste incondensible gases
and tars produced are used for fuel at various stages, and electricity lends
its wonderful help in different ways. All these economies have given much
importance to the question of the future life of the shalefields, in which,
no doubt, an immense quantity of oil—and ammonia producing shale of various
qualities—still exists for future development."
"The companies," says a
writer in The Scottish Bankers' Magazine of January, 1913, "employ in their
mines and works fully 10,000 men, paying in wages £1,000,000 per annum. In
addition, a large number of men are indirectly employed in the production of
fuel, chemicals, and plant. . . . The total capital of the six limited
liability companies, whose shares are publicly quoted, is approximately
£1,670,000. . . . Last year's aggregate net profits amounted to
approximately £165,000."
By the beginning of the
nineteenth century the annual production of pig-iron was about 20,000 tons.
At the end of the third decade of the century it had grown to about 37,000,
whilst the number of furnaces had risen, during the same period, from 17 to
27. The invention of the hot blast by Mr Neilson, manager of the Glasgow Gas
Works, in 1828, quickly multiplied production. This expedient consisted in
heating the air before injecting it into the furnaces, and the substitution
of the hot for the cold blast reduced the quantity of coke consumed in the
smelting of one ton of iron from 8 tons If cwts. to 2 tons 13£ cwts. Raw
coal instead of coke was first used at the Calder Ironworks in 1831, and its
use resulted in a further saving of fuel. This substantial reduction in the
cost of production gave a great impulse to the industry. By 1836 the annual
total of pig-iron had risen to 75,000 tons, in 1845 to 475,000, in 1855 to
820,000, in 1865 to 1,164,000, and in 1880, 1,049,000. The highest total
reached within the period 1845-80 was 1,206,000 in 1870. It thus multiplied
the number of smelting works, some of which were established in the west of
Fife as well as on 1|e south side of the Forth. But it was in the west that
the industry attained its full development. As early as 1786 the Clyde
Ironworks had been established by Mr Cadell, one of the original partners of
the Carron Company, in the parish of Old Monk-land, and it was here that
David Mushet, the discoverer of the "black band," and later Mr Neilson, the
inventor of the hot blast, carried out the experiments that contributed so
much to its development.
The most valuable deposits of
ironstone are situated in Lanarkshire and Ayrshire, and it was in those
districts, where in 1901 there were 79 furnaces in blast, that production
was centralised. Most of the works were started between 1830 and 1840. The
more important of those in Lanarkshire are at Coatbridge, Coltness, Govan,
Tollcross (the Clyde Works), Carnbroe, Calder, Wishaw, Sbotts; in Ayrshire,
Glengarnock, Eglinton, Lugar, Dalmellington, Muirkirk, Ardeer. The largest
are those at Gartsherrie, Coatbridge, belonging to Messrs Baird & Co., who
were the first to apply the hot blast, and who also own the works at
Eglinton and Lugar. Coatbridge, where those of the Summerlee and Langloan
Companies are also situated, is in fact a town of blast furnaces. Besides
pig-iron, bye-products such as tar and ammonia are obtainable by
condensation of the gas given off by the coal, which is also used for
heating the blast. Messrs. Baird were the first to erect machinery for this
purpose in 1880.
"Blast furnaces, fairly
familiar objects, are large, circular, tower-like erections. The interior,
which is not straight in form, but contracts towards top and bottom, is
lined with refractory fire-brick and ganister (a very refractory siliceous
rock); around this is an annular space or ring filled with loose material to
allow of expansion, and the outer wall of masonry is enclosed in iron
sheathing strongly bound together. The furnaces range from 40 feet or so to
100 feet, and even more, in height, with internal capacity of 500 to 25,000
cubic feet or over. The modern furnaces are the highest, but it has been
found that practical difficulties in working counterbalance the advantages
of greater height when carried beyond a certain point. One advantage of the
higher furnace is to render previous calcining of the ore less necessary,
the same effect being accomplished in the upper part of the furnace. At the
top of the furnacc is a gallery or platform from whence the charge is
admitted. The mouth of the furnace is closed by means of a large cone, which
can be lowered by a chain when the charge is being admitted and then closed
again. The closed top is a modern advance. Formerly the mouth was open, and
the great, lurid flames belching out made the blast furnace a picturesque
feature of the district where it was erected. Many well remember the time
when "Dixon's blazes," as they were familiarly called, formed a landmark in
Glasgow; and when shipmasters on the Ayrshire coast could shape their course
by the glare of the Ardeer furnaces. But the old order changes, and the
picturesque has given way to the practical. The closed tops came into being
when the gases generated in the blast furnace were utilised with resulting
efficiency and economy . . . The charge consists of fuel, ore, and flux. The
first is commonly coke, but may also be coal or a combination of both . . .
The flux is commonly limestone, although other agents are also used. It is
introduced in consequence of the impurities remaining in the ore. It
combines with the silica and other prejudicial matter and forms a slag or
cinder separated from the iron. A strong blast of air is introduced through
piping surrounded by water tuyeres (outer casings). Powerful blowing engines
force the blast into the furnace and through the charge therein. The water
circulating through the tuyeres serves to cool the inlet where the heat
becomes intense and might cause trouble by fusing the parts. ... As the
charge becomes affected by the intense heat, chemical and other changes take
place, impurities being taken up by the flux, though some others partially
remain, as sulphur, phosphorous, and carbon. After these changes, fusion
speedily ensues, and the molten iron falls to the bottom, the slag floating
on the top, while other waste elements escape in the form of gases. ... At
the bottom of the furnace is an aperture called a tapping-hole, kept closed
till the melting of the iron is completed. A large bed of sand is formed in
front of the furnaces in which channels are made with smaller furrows
branching off from them. These are called sows and pigs respectively, whence
the term pig-iron, The tap hole being opened the melted iron runs out like a
stream of liquid fire, flows down the large furrows into the smaller ones,
where, on cooling, it assumes the familiar form of the oblong bars called
pig-iron."
The diminishing supply of
ironstone led to the importation of ore from Spain and other regions, which
is landed at Glasgow or Ardrossan. About 115 million tons have been mined in
Scotland, and though the total Scottish ironstone has been reckoned by
Professor Louis as high as 8,000 million tons, only a relatively small
portion of this vast quantity can be economically utilised. The bulk of the
more valuable Scottish deposits is now, in fact, exhausted, and there has
been a decline in the Scottish ore mined from well over 2i millions in 1880
to over half a million in 1913. Recently, however, a large deposit has been
discovered on the island of Raasay, Skye, from which the first consignment
was shipped to Glasgow in 1911. On the other hand, the quantity of ore
imported has risen enormously from about 42,000 tons in 1879 to nearly li
millions in 1899. Another reason for this importation is the need for
pig-iron free from phosphorus for the manufacture of mild steel, for which
the Scottish pig-iron is unsuitable. In 1900 the output of pig-iron amounted
to 1,156,885 tons and was slightly below the total of 1865, but in 1910 it
had risen to 1,427,828, and in 1913 to 1,369,259. The Carron Company, which
still holds a foremost place in the industry and uses only the black band
from its own mines, produces over 2,200 tons per week.
The Carron Works long held
the pre-eminence in the manufacture of malleable iron and iron goods, though
the making of cannon, for which they were famous, ceased about the middle of
the nineteenth century. In 1819 a rival appeared in the Falkirk Iron Works,
which were started by some enterprising workmen from the parent company, and
developed into what was for a time the second largest foundry in Scotland.
By the year 1880 there were 21 foundries in the district, which, with the
Carron Works, gave employment to 6,000 men. Foundries also sprang up at
Edinburgh, Leith, Dalkeith, Kirkcaldy, Dundee, and Aberdeen. At Carron,
besides the famous "carronades," as the small cannon were named, the
articles manufactured were mainly those in domestic use, such as stoves,
grates, cooking ranges, boilers, pots, rain pipes. At the Falkirk Works,
which in 1848 passed into the hands of the Messrs Kennard, the products
included the castings of iron bridges, such as the Solway Viaduct, and a
large variety of artistically designed articles for practical or ornamental
use.
With the development of the
pig-iron industry the production of cast iron and malleable iron also
shifted its centre to the west, many of the foundries being connected with
the blast furnaces, though this connection ultimately ceased, and iron
manufacture became a separate industry. Coatbridge is the chief centre of
it, but Motherwell and Wishaw are good seconds. Before the substitution of
mild steel for iron in shipbuilding and other industries, large forgings in
the shape of plates, armour, shafts, etc., were produced, and it was to meet
the necessity for a more serviceable instrument in forging huge products of
this sort than the tilt hammer of James Watt that James Nasmyth, the
engineer and son of the painter, invented the steam hammer in 1839. Cast
iron is manufactured for castings, such as water and gas pipes. It is hard
and brittle and cannot be welded or rivetted and is not pliable. Malleable
iron, on the other hand, is ductile and fibrous and can be bent, twisted,
welded, and rivetted. Its manufacture begins in the puddling furnace, in
which the melting pig-iron is stirred or puddled by an iron rod, usually
moved by the hand of the puddler, but in some works by mechanical means,
until it attains a certain degree of consistency. The quantity of pig-iron,
known as "a charge" placed in the furnace at one time, is about cwts., and
the time occupied in puddling it is from two to three hours, so that five or
six charges can be worked in twelve hours, the quantity of pig-iron used in
the puddling of a ton of puddled iron being from 22 to 23 cwts. The charge
is then conveyed in portions to the steam hammer, which expels the slag or
dross and beats it into shape, the "shingler" turning it on the anvil
between each stroke. It is then passed into the rolling mill to be drawn
into bars. Thereafter it is cut into short lengths, and these are
transferred to the "re-heating furnace " in the proportionate number
required for the manufacture of a specific bar, heated to the welding point,
removed and rolled again, and finally cut by a circular saw to the required
length. In the case of the finer quality of iron a second welding and
rolling is added, gas furnaces of the Siemens type being now largely used in
the reheating process. The work of the puddler and other skilled operatives
is a very exacting and exhausting one, demanding close attention and great
physical exertion.
The substitution of steel for
iron has greatly limited the purposes for which iron is used. Nevertheless
the quantity produced is still relatively large. In 1867 the number of
puddling furnaces in operation was about 400, that of rolling mills 50,
which produced 143,800 tons of malleable iron. In 1900 there was about the
same number of furnaces at work at Coatbridge, Motherwell, and Wishaw, and
the produce was 147,904 tons. The number of firms engaged in the industry
was 22, owning 25 works.
"No new process having been
introduced in the manufacture of puddled iron," says Mr Wylie, "the
fundamental principles are just the same as have been in operation for the
last 50 years or more, so that the only means of lowering the costs, in
order to meet the keen competition of modern times, is by adopting from time
to time all the minor improvements in furnaces and machinery, whereby the
waste of material and consumption of fuel is lessened and the output
increased, while the general wages and charges are reduced. In this respect
the various works have not been slow in adopting any means which they
considered would be a benefit to them in their respective branches."
The output of malleable iron
is now far outdistanced by that of steel. Several attempts were made in
Scotland in 1857 and the following years to manufacture steel by the
Bessemer process, but the results were not satisfactory, owing to the
unsuitability of Scottish pig-iron. In 1871 the Steel Company of Scotland
was formed for the manufacture of steel by the Siemens, or acid open-hearth
process, at Hallside, Newton, and up to the year 1879 this Company was the
sole manufacturer of steel in Scotland. In 1878 its output had risen to
about 42,000 tons, and two years later (1880) it acquired the Blochairn
Works at St Rollox, Glasgow. In the previous year Mr Beardmore erected
furnaces at the Parkhead Works in the same city. From this date to the end
of the century a considerable number of other works were established in
Glasgow and the west. Among the largest are those of Beardmore & Co., the
Steel Company of Scotland, David Colville & Sons, Motherwell; the
Lanarkshire Steel Company, Flemington; the Glasgow Iron and Steel Company,
Wishaw; the Glengarnock Iron and Steel Company; the Summerlee and Mossend
Iron and Steel Company. In 1899 there were 115 open-hearth furnaces and the
average number in operation during this year was 90. Already in 1883, the
output had risen to 230,000 tons of ingots, yielding over 90,000 tons of
plates, 35,000 tons of angles and bars, and 20,000 tons of sundry products.
In 1900 the total of ingots was nearly 1 million tons, yielding 300,589 tons
of plates and angles, 199,359 of bars, etc., and 56,839 tons of blooms and
billets,—a total of 016,787 tons of finished steel. In 1912 the total of
finished steel had swelled to nearly 1 million.
A corresponding advance has
taken place in the equipment of the industry. In 1885 the largest smelting
furnaces had a capacity of about from 15 to 20 tons. In 1900 it had risen to
from 50 to 60 tons with a corresponding improvement in the appliances for
handling such large quantities of molten steel. The old coal-fired
horizontal furnace has been superseded by the vertical gas-fired
regenerative furnace with cranes of various type for charging and drawing
the ingots. The steam hammer has been displaced by the modern slab cogging
mill, with the necessary appliances, worked by hydraulic power, and capable
of turning out from 60 to 70 tons of steel per hour. The plate and bar mills
have been similarly equipped. Such appliances have become a necessity in
view of the largely increased size of steel slabs and plates, with the
result of lessening the strain of manual labour and effecting economy in
production.
Some firms like the Messrs
Beardmore and the Messrs Brown combine steel production with shipbuilding,
and are capable of building and equipping the largest warships and other
vessels from their own resources. Many other firms are engaged in one or
other of the branches of mechanical engineering, such as iron and
brassfounding, boilermaking, machine toolmaking, the making of sugar
machinery, locomotives, motor cars, textile machinery, sewing machines,
agricultural implements and machinery, electrical plant, sanitary, lighting,
and heating appliances. Not a few of them occupy a leading position in their
specific industry and send their products all over the world. The North
British Locomotive Company of Glasgow, for instance, sends locomotives to
India, Japan, South Africa, America, and elsewhere, and formerly to Germany.
It employs between 7,000 and 8,000 men, and turned out in 1911 7,340
locomotives. In the same year the Caledonian Railway Company's Works at St
Rollox completed 2,758, the North British Railway Company's Works at
Cowlairs 2,351, and those of the Glasgow and Southwestern Railway at
Kilmarnock also 2,351. |
