three species of animals possessing a high interest for naturalists and
others—not so much because their existence has been discovered in recent
times, as because they are illustrations of the great law of gradation
which exists in nature. Their position in the scale of organization is
so intermediate between reptiles and fishes, that naturalists have not
entirely agreed as to the kingdom to which these ought to be assigned.
Fig. 326 represents _Lepidosiren annectans_, which has gills covered by
flaps, and not exposed as they are in ordinary amphibious animals; and
is provided with four fins, or rudimentary legs, according as the reader
may choose to call them. The creature’s nostrils do not communicate with
the mouth, but are merely two blind sacs, as in fishes. The _Proteus
anguinus_, shown in Fig. 325, is an eel-like creature, only met with in
the subterranean waters of the Grotto of the Maddalena at Adelsburg. It
has four imperfectly developed legs, and gills reduced to mere fringe,
while there are lungs extending nearly the whole length of the abdomen.
The optical organs are entirely undeveloped, being represented merely by
two specks. The axolotl, Fig. 327, inhabits certain Mexican lakes, and
is remarkable for preserving, through the whole period of its life, the
gills for aquatic respiration, which other _amphibia_ possess in the
tadpole stage only.
[Illustration:
FIG. 326.—_The Mud-fish (Lepidosiren annectans)._
]
The mania for domestic aquaria which was at its height some years ago,
and the great popularity of public marine aquaria wherever they are
properly managed, express the real interest which is felt in the varied
forms of animal life, of which the aquarium affords the opportunity of
observing new and unknown phases. The progress of the science which
treats of the organization of the animal kingdom has made rapid strides
during the present century. Among the remarkable truths which have been
acquired is the fact of the unity of the plan which pervades the animal
kingdom. Each kind of animal has much in common with the kind above it,
and with the kind below it: a certain community of organization pervades
the whole, which is knit into one by the gradational forms which may be
observed connecting, like links of a chain which cannot be broken, the
more defined modifications from each other. It is their position in the
scale of organization which, in the eyes of the philosophic naturalist,
gives so much interest to some of the forms of life which have been
figured above.
[Illustration:
FIG. 327.—_The Axolotl._
]
[Illustration:
FIG. 328.—_Sorting, Washing, and Digging at the South African Alluvial
Diamond-Fields._
]
GOLD AND DIAMONDS.
It need hardly be said that gold and diamonds are named under nineteenth
century discoveries in relation to the newly-found fields which have
yielded these highly-prized substances in remarkable abundance.
_GOLD._
This precious metal is met with in nearly all parts of the world, and
its splendid colour, high lustre, the ease with which it may be wrought,
and its property of ever remaining untarnished, have caused it to be
greatly esteemed for ornamental purposes from the earliest historical
ages. No doubt the store set upon gold is derived from its suitability
for decorative uses; and its comparative scarcity enhances the regard in
which it is held. Its use, as a standard of value, is justified by the
general estimation in which it is held, and by the fact that the amount
of labour required to obtain the metal is on the whole tolerably
uniform. It is one of the few metals which are found in nature in the
uncombined state, but its separation from the materials with which it is
associated requires the performance of a certain amount of work, in
whatever form the metal may occur. Its general distribution is another
advantage attending its selection as the standard of value. It occurs in
England and Wales; in Spain, in France, in Hungary, in Piedmont, and in
other parts of Europe; in various localities in Asia; in both divisions
of the New World; in the remaining quarter of the globe, where it was
obtained even in very ancient times, for South-East Africa was probably
the locality to which a naval expedition was despatched by King
Solomon—“they came to Ophir, and fetched from thence gold.” Australia
also has, in the last half of our century, yielded much gold.
Gold is never met with in regular veins, but in primitive or igneous
rocks, or in deposits formed by the disintegration of these. In
Australia the metal is associated with quartz, in slate rocks
geologically equivalent to the Cambrian formations of England and Wales;
and in California it is also chiefly found in material which has been
formed by the wearing down of quartz and granite rocks. Before the
discoveries in California and Australia most of the gold in circulation
was obtained from auriferous iron pyrites. The first finding of gold in
California occurred in September, 1847, when a Mr. Marshall, the
proprietor of a saw-mill on the Sacramento River, observed some
glistening grains among the sand in his mill-race. The news soon spread,
and the inhabitants of the town of San Francisco, then numbering about
two hundred persons, were greatly excited thereby. When it became known
that gold was really to be found, multitudes flocked to California, the
population of San Francisco rapidly increased, and at the present day
the city contains nearly a thousand times as many inhabitants as it did
at the time gold was first discovered. The annual value of the metal
found in California averaged about £23,000,000 for ten years after 1851;
but this subsequently declined to less than half in 1872.
Sir Roderick Murchison, the distinguished geologist, pointed out the
great probability of the existence of gold in Australia many years
before the precious metal was actually found. It has, however, been
stated that gold was met with in Australia so long ago as 1788.
Considering the mode in which the metal occurs, it seems strange that
the emigrants who occupied the auriferous districts as agriculturists
did not long ago discover the riches which Nature had scattered over the
surface of the soil. No doubt, their attention was too much devoted to
their sheep and cattle to notice the glittering particles which might be
seen in the water-courses, and it would probably never enter their minds
that the eagerly desired metal could lie exposed to view on the surface
of the land. But the announcement of the discoveries in California
induced men to look at the soil more attentively, and in April, 1851,
Mr. Hargreaves appears to have found at Bathurst the first gold met with
in Australia. Four months afterwards the metal was also picked up at
Ballarat, Victoria, and the gold-fields so discovered proved even richer
than those of Sydney.
The effect of this discovery on the colony of Victoria proved
marvellous. The population, which in 1851 was 77,000, had in 1867 become
660,000; in the same period the land under cultivation expanded from
57,000 acres to 631,000, and the value of property rose enormously when
the grazier’s estimate of its worth was replaced by that of the miner.
The authorities of the colony from the first regulated the mining
operations by enactments defining the rights of the miners to the
“claims,” as the allotments of land for working upon are termed; and
thus disorder and lawlessness were almost unknown. Fig. 329 will give
the reader a notion of the appearance of a miners’ settlement in the
Australian gold-fields in the earlier period.
[Illustration:
FIG. 329.—_Gold Miners’ Camp._
]
The fundamental rocks in the colony of Victoria belong to the oldest
series of strata. They answer to the Silurian formation which exists in
Cumberland, Wales, and Scotland. Although the strata of the rocks are
much bent, and they have been worn down by the action of water, they are
as a whole but little altered, consisting chiefly of sandstones and
shales. These strata are interpenetrated by innumerable veins of quartz,
which vary in thickness from 1/16 in. to 150 ft. It is in these quartz
veins that the gold is seen in its original matrix. The metal is
sometimes in the form of grains or flakes, or in moss-like threads,
embedded in the quartz; sometimes in the form of well-defined crystals,
sometimes in rough lumps or _nuggets_. Fig. 330 shows three of the
various modes in which the gold is found disseminated through quartz.
Overlying the more ancient rocks with their auriferous quartz veins are
various rocks of different ages; and as these have been in part formed
by the wearing down of the older rocks, they also are in general
auriferous, and contain the gold in detached pieces, varying in size
from particles of fine dust to the huge nugget, containing 2,280 oz., or
nearly £10,000 worth of pure gold, which was found at Dunolly.
The soil, which has been formed by the disintegration of masses of
auriferous quartz, is full of gold, so that a patch of such soil 12 ft.
square has been known to yield 30 oz. of gold by a very rough kind of
washing to the depth of 1 ft. Soil of this kind has been carried down by
rivers and streams ages ago; and the lighter particles having been
carried off by the water, while the gold, from its greater specific
gravity, remained at the bottom of the stream, the sands and gravel of
these river-beds are very rich in gold. In many instances the ancient
water-courses have been entirely covered by igneous rocks, such as
basalt, which have flowed over the land in a molten state. The
gold-miner often finds his reward in burrowing beneath these basalts and
lavas, following the bed of the ancient river, and recovering its
long-buried treasures.
[Illustration:
FIG. 330.—_Gold in Rocks._
]
[Illustration:
FIG. 331.—_“Cradle” for Gold-washing._
]
The methods of carrying on the gold-seeking operations vary according to
the nature of the deposit which is worked and the resources of the
miner. The simplest, which was that most practised in the early days of
the gold-fields, consists in throwing into a tub several shovelsful of
the surface soil, and in pouring in water while the contents of the tub
are stirred about with a spade. The lighter matters are washed away, but
the gold by its great specific gravity remains behind. An improvement in
this, but still a very rude process, is practised by aid of the
_cradle_, Fig. 331, which is merely the trunk of a tree, hollowed out,
and provided with transverse partitions and ribs. The auriferous earth
is thrown into the upper compartment, which is then filled with water.
The cradle is rocked, so that the water may wash away all but the gold
and the heavy stones. Any particles of the former which may be carried
out of the head of the cradle will be stopped by the ribs which cross
the lower part. Machines for puddling by horse-power are now in use, and
other contrivances have superseded the tub and the cradle in
_surface-washing_. The auriferous earth obtained by excavating the soil
from pits is washed in a similar manner, as is also the material reached
by penetrating the deeper tertiary deposits, and by driving adits or
tunnels along the ancient river-beds beneath the layers of basalt.
A mode of washing accumulations of auriferous earths by streams of water
is employed where circumstances are favourable. A long inclined channel
is constructed, and lined with boards; or, when the natural inclination
of the soil requires it, a long trough is constructed and supported on
trestles. The trough is made of sawn boards, 1½ in. thick, in sections
12 ft. long, and it has a width of about 1 ft., the sides being from 8
in. to 2 ft. high. The inclination of the troughs is from 8 in. to 24
in. in 12 ft., and depends upon the abundance of the water: the more
water, the steeper is the slope. The bottoms of the troughs are crossed
by a number of transverse bars, which arrest the auriferous particles in
their descent. The _sluice_, or series of troughs, may be from 50 ft. to
several hundreds or even thousands of feet in length, and the cost from
£100 to £8,000. The earth is thrown in at the upper part of the trough,
and it is gradually washed down, the water being allowed to flow in some
cases by night as well as by day, but commonly in the day-time only, as
the troughs must be watched, to see that they do not become choked up,
and the soil washed out by the overflowing water. The _run_ goes on for
six or ten days, and then the current is stopped for a _cleaning-up_,
which occupies from half a day to a day. For this operation the stream
of water is stopped, and quicksilver is used to dissolve the grains of
gold from the sand, &c., collected by the _riffle-bars_. The quicksilver
is afterwards expelled from the amalgam by heat, and the gold remains as
a porous mass.
Sometimes, instead of shovelling the earth into the troughs, it can be
washed out of its position into suitable channels by means of a powerful
jet of water. This mode of working, which is termed _hydraulic jet
sluicing_, offers great advantages where the natural conditions admit of
its adoption. In this plan, instead of bringing the auriferous earth to
the water, the water is brought to the earth by a flexible pipe, like
the hose of a fire-engine, from a reservoir about 200 ft. higher, and
the stream is directed upon the material by a nozzle. This powerful jet
of water is used to separate and carry away the earth to the head of a
system of channels and troughs, like those already described. The hose
has a diameter of 8 in., but the orifice of the nozzle from which the
water issues is contracted, in order to increase the force of the jet.
The hydraulic jet sluicing requires from three to six men to work it,
and the material of a hill can be carried into the sluices in less time
than a hundred persons could do it by spades. Immense quantities of
earth are removed in this way, and fatal accidents are not infrequent
from the falling masses burying the men who carry the pipe. The force of
the jet of water itself is another source of danger, for broken limbs
and even fatal injuries have often been caused by it. The number of
accidental deaths occurring in hydraulic jet sluicing operations in the
colony of Victoria is reported to average about 60 in a year. Material
which has been worked before often yields a considerable amount of gold
when the operations are repeated; and in localities favourable to the
hydraulic jet system, the work can be carried on with little labour. In
this way three men have been known to extract in one week from dirt
washed for the third time, gold of the value of £330.
The gold which is embedded in quartz and other minerals, as shown in
Fig. 330, is obtained by crushing the material in stamping machines,
which are usually constructed with logs of wood shod with iron. In
another form of crushing-mill two large cast-iron rollers are used
instead of stampers. From the crushed material the particles of gold are
extracted by amalgamation with mercury, which is afterwards removed by
distillation.
The richness of the Victoria gold-fields may be inferred from the fact
that, up to the year 1868, 36,835,692 oz. had been obtained, the value
of which is no less than £147,342,767. The total value of the gold then
annually obtained throughout the whole world is estimated at about 20
millions of pounds sterling. When gold was found so plentifully in
California and Australia, it was supposed by some that its value as a
monetary standard would be affected. This has not happened, although the
prices obtained for the metal by its producers were considerably lower
in the last decade of the century than about 1867. The total annual
output of gold throughout the world is of course variable, and no doubt
there are also variations in the demand; but, so far, the fluctuations
have been relatively small, and there has been no such depreciation by
excess of production as in the case of silver. Yet the increased
production of gold after the discoveries made about the middle of the
century was beyond precedent. It has been estimated that between 1850
and 1875 the total value amounted to £600,000,000, showing an annual
average twelve times greater than that for the period between 1700 and
1850. Between 1875 and 1890 there was a falling off in the supply, the
annual average becoming only £20,000,000 in value. But since the
last-named date there has been a rise year by year, and at the close of
the century the value of the gold produced throughout the world in one
year may not be less than £40,000,000.
As already remarked, the distribution of gold is world-wide; and it has
happened in recent times, that just as one source of supply has shown
signs of failure, other fields have been discovered and have attracted
thousands of eager seekers to new regions. So, when the Californian
supply was falling off, there came the rush to Australia, where easily
worked alluvial deposits or rich veins continued for years to reward the
toil of the gold-finder, though in an ever-lessening degree, until in
1886 or 1887 the centre of attraction was shifted. But at a later period
fresh discoveries in Australia again raised the productiveness of that
quarter; and still more recently, the announcement of the existence of
much auriferous deposit in the valley of the Yukon River (Klondyke), and
in various localities of British Columbia, drew thousands to desolate
and undeveloped districts, in spite of the extremities of hardship and
destitution that might be endured.
The discovery of 1886 takes us to South Africa, a region with which also
our next section is mainly concerned, and the scene of an activity
unprecedented in the annals of gold-mining. From circumstances
immediately connected with our present subject, the close of our century
finds public attention intensely occupied with affairs at the austral
extremity of the “dark continent.” The history of South Africa, from the
time when, in 1486, the tempest-driven Portuguese mariner, Bartholomew
Diaz, first struck its shores at the promontory he named the “Cape of
Storms” (_Cabo Tormentoso_), and when, eleven years afterwards, the
celebrated Vasco de Gama sailed round it on his memorable voyage to
India, is one which, in many respects, presents features of peculiar
interest. It is not our province to enter into details of these, but it
may be stated that the “Cape of Good Hope”—the more auspicious
designation which the King of Portugal substituted for that of Diaz—was,
towards the end of the seventeenth century, colonized by Dutch and some
French settlers, and afterwards Table Bay became a regular port of call
for Dutch, English, and other ships trading to India. The Cape was taken
possession of by the British in 1795, but restored to the Dutch in 1803,
only to be three years after (1806) resumed by England, under whose rule
“Cape Colony” has since remained. The abolition of slavery in all
British dominions, enacted in 1833, was the occasion of great
dissatisfaction to the descendants of the Dutch settlers, who inhabited
isolated farmsteads, their possessions consisting chiefly of great herds
of cattle, tended by slaves. These people, or at least the majority of
them, resolved to quit the confines of British territory, and seek fresh
fields and pastures new in unoccupied regions north of the Orange River,
so that from 1835 to 1838 there was a continued “exodus of the emigrant
farmers.” The story of the following years, with its exciting events and
the vacillating policy of successive British Governments, must be
perused elsewhere: suffice it to say here, that the settlements of the
“emigrant farmers” had by 1854 established themselves into two separate
States, nominally recognising Great Britain as the “paramount power,”
but practically independent of it; for, at the last-named date, the
autonomy of “The Orange River Free State” was acknowledged, and two
years before that another section of the Boers, _i.e._ of the “emigrant
farmers,” who had settled beyond the Vaal River, was absolved from
British allegiance, and, restricted only by a claim of certain suzerain
powers, was constituted into “The South African Republic,” of which the
precise boundaries were at length determined by the “Convention of
London” in 1884. This territory is usually called for shortness the
_Transvaal_, and here in 1854 the existence of gold was first announced;
but the Boer authorities at once prohibited further prospecting,
fearing, and perhaps with reason, that the winning of the precious metal
within their bounds might disturb their pastoral quietude. The Boer
character has been the unique product of a race withdrawn for two
centuries from contact with European and civilized culture, living in
widely separated dwellings with scarcely other associations than cattle
and enslaved blacks. The Boer is described as of a type which draws away
from the enterprising man of modern times towards the primitive
patriarch centred in his flocks and herds: he hates innovations, and
greatly distrusts strangers; he would rather keep, in a box under his
bed, any money he may possess than employ it, or his own energies, in
developing the immense mineral resources of his territory, in which are
included not only gold, but copper, silver, lead, iron, and abundance of
coal.
After some years the prohibition against the exploitation of gold in the
Transvaal was withdrawn, and several localities in the Republic
subsequently became small capitals of gold-mining industry. The most
notable were Leydenburg and Barberton, at which latter place as many as
10,000 gold-seekers were congregated when the discovery of 1886 drew
most of them away. These communities were formed almost entirely by the
influx of people from beyond the Boer boundaries, mainly, of course,
English-speaking people from the Cape Colony, Australia, America, etc.
Their operations were hampered by the Transvaal legislation, and impeded
by the absence of adequate means of communication, which was a
characteristic feature of the Boers’ unprogressiveness; nevertheless,
gold-mining has been pursued in some of these localities ever since,
though with varying fortune. What drew nearly all the gold-seekers of
the Transvaal and of adjoining regions at once to the north side of the
Vaal River was the discovery there of _real gold mines_. This was at a
district within the Transvaal territory, named Witwatersrandt (=
White-waters-ridge), the designation which has been reduced by
abbreviation or affection to “The Randt”—or, _anglice_, the Rand.
It is singular that although the Randt district had been explored by
expert prospectors between 1877 and 1891, the outcrops of the auriferous
reefs entirely escaped their notice. But when the first hint of the
existence of these deposits was bruited abroad, it was the Kimberley men
who were foremost in surveying the spot. By the Kimberley men we mean
those who so soon had by lucky chance lighted in 1870 upon the rich and
apparently inexhaustible diamond mines, as related in our next section.
By the time of the announcement of gold-finds on the north side of the
Vaal River many of these men had become rich—very rich indeed. If they
had been so disposed they might then have returned to their native
countries with enviable fortunes, but it was just as the affairs of
their diamond companies had been settled by consolidation on a
satisfactory basis, and the spirit of discovery and adventure was still
strong upon them, that they resolved personally to explore the new El
Dorado. To a wild desolate region they proceeded, enduring there and on
the track thither the like discomforts they had experienced in their
earlier quest. But they took with them experts provided with all
appliances for ascertaining the prospective value of the alleged
discovery, and, when convinced of its reality, they purchased from the
Boer possessors their land at the price demanded, and it was not long
before they had chemists and engineers at work, having, at the cost of
making their own roads, had brought to the spot the necessary machinery
and appliances. The usual influx of workers, builders, speculators,
etc., followed, and in a wonderfully short space of time a town sprang
up where in 1886 there had been only a single poor farm. The town grew
rapidly to the dimensions of a city inhabited by 150,000 people. Its
name is Johannesburg.