THE RIGHT-HAND BRANCH OF THE IMPERIAL CAVE.
Having thus completed his inspection of the left-hand branch of the
Imperial Cave, the visitor returns to the junction, passing through all
the chambers previously noticed in it excepting the Architect's Studio
and the Bone Cave, and proceeds to explore the still more wondrous and
beautiful works in the right-hand branch.
THE SUBTERRANEAN RIVER.
The first object of interest in the right-hand branch of the Imperial
Cave is the Subterranean River, which runs at the bottom of a fearful
chasm about 50 yards from the point where the two branches bifurcate.
After having wandered through marble halls and crystal palaces, and
bowers where "rural fays and fairies dwell," the course seems rather
gloomy. But attention is attracted by some curiously-shaped nodules,
like those found in a part of the Arch Cave, and by basins with thin
laminated sides slightly corrugated. These specimens reveal the secret
of the construction of the pretty reticulated mounds, which give such a
charming effect to several of the most regularly formed features of the
caves. To complete the process, the sharp parallel lines which form a
succession of little equidistant ridges require only to be smoothed off
by a gently flowing film of water, and to receive a coat of colouring
derived from clay or oxide of iron. This part of the branch, therefore,
should not be passed through hurriedly, for it is instructive.
[Illustration: THE UNDERGROUND RIVER AND ITS REFLECTIONS.]
The road is fairly good, although the arching is low. Those parts, the
narrowness of which formerly made progress difficult, have been
enlarged, but a pretty natural bridge has been carefully preserved. The
halt is at the end of a wire ladder bent over a cliff, which forms one
side of an immense gulf, where perpetual darkness broods. Here the
visitor has a more ungraceful task to perform than that of the cursed
serpent, for he must recline face downwards and "progress backwards"
until he assumes the form of an obtuse angle, with one line over the
precipice. Then he has to use his legs pretty much as an octopus uses
its tentacles, to gain a footing on the ladder, which descends about 50
feet on the chasm side of the angle. Having found the first rung he
feels happy, but not sufficiently hilarious to slide like a lamplighter.
He grips the side wires carefully, takes heed to his steps, and goes
down slowly. When he has descended a little way, the dim candle-lights
above appear to be far distant, and when he is 20 or 30 steps down they
look like glowworms. The journey, however, is not perilous to persons
who possess a fair share of agility and nerve. It is frequently
performed by ladies, of whom the guide is specially careful, preceding
them and keeping just below them on the ladder. As this is, perhaps,
the most interesting of all the cave sights, it is desirable that some
easy mode of descent should be provided, such as a skip like those
employed in mines, or a lift made by machinery to work as easily and
effectively as those which ascended and descended at will in the
subterranean world inhabited by "the coming race." It was, perhaps, some
such place as this which suggested to Bulwer Lytton the chasm down which
his nameless hero descended to the bottom of an abyss illuminated with a
diffused atmospheric light, soft and silvery as from a northern star;
where he found lakes and rivulets which seemed to have been curbed into
artificial banks, some of pure water, and some which shone like pools of
naphtha; where the birds piped in chorus, and where he made the
acquaintance of the An people and the Gy-ei, who moved through the air
without effort, who had for servants automata always obedient, and
totally ignorant of the eight-hours system, and whose religion had these
two peculiarities: "Firstly, that they all believed in the creed they
professed; and, secondly, that they all practised the precepts indicated
by the creed."
Underground rivers appear to be natural to limestone caves. The reason
of their existence is to be found in the fact that the mountains in
which they are formed are, in geological parlance, "dykes." They must
not be confounded with old river beds, such as are encountered by
miners--where the surface of the earth has been raised by deposits of
alluvium, or where the geological condition of things has been changed
by volcanic action. These cave rivers have all been formed by water
finding the lowest attainable level in its passage to the sea, and by
the solid limestone rocks which have barred its direct course, and have
been undermined by its subtle but persistent action. The fluid, dammed
back by the mountains, has simply obeyed the laws of gravitation and
accumulated force, as evidenced in the trickling silvery thread which
follows the course of ant-tracks; in the laughing rill which makes its
bed among the pebbles; in the babbling brook which leaps to the swelling
river; and in the mighty torrent whose strength and velocity proclaim
the majesty of hydraulic power. In all parts of the world where
limestone dykes and caves exist, it is reasonable to expect to find
subterranean rivers. The eye of the seer can follow the water drips--
"Down through caverns and gulfs profound,
To the dreary fountain-head
Of lakes and rivers underground."
He can see them again when the rain is done--
"On the bridge of colours seven,
Climbing up once more to heaven,
Past the setting sun."
But the underground rivers found in caves perform vagaries outside the
sweet imaginings of the poet and the prevision of the seer. Far from the
beaten track they turbulently force their way through recesses and
tunnels and pockets of the earth, before they are again warmed with
sunshine, and glow in the harmonious colours which form the Bow of
Promise.
The Rev. Richard Taylor, in his "_Te ika a maui_," refers to interesting
caves near Mokau (New Zealand), in some of which bones of the moa have
been discovered. About a mile from Pukemapau he came to a limestone
range, and entered a large cave called Tanaureure. At the bottom of a
chasm he found a fine crystal spring, about a foot or so deep, but
appears not to have been particularly inquisitive as to whence the water
came or whither it went.
A little distance up one of the tributaries of the Rewa River, in Fiji,
is a crystal streamlet which flows on towards a lofty ridge, near to
which it sinks into the earth. At the mouth of a dark cavern can be
heard the roaring. It is a grand expansive excavation, but
"Dark as was chaos ere the infant sun
Was roll'd together, or had tried his beams
Athwart the gloom profound."
The water rushes through narrow chasms as through a race, collects in a
large pool, and flows through a distant outlet, marked by a speck of
light, like a tiny star.
At the Weathercote Cave, in Yorkshire, a stream swallowed up by a rocky
mouth is thus described by Walter White in his book entitled "A Month in
Yorkshire":--
"The rocks are thickly covered in places with ferns and mosses, and
are broken up by crevices into a diversity of forms, rugged as
chaos. A few feet down, and you see a beautiful crystalline spring
in a cleft on the right, and the water turning the moss to stone as
it trickles down. A few feet lower, and you pass under a natural
bridge formed by huge fallen blocks. The stair gets rougher,
twisting among the big, damp lumps of limestone, when suddenly your
guide points to the fall at the farther extremity of the chasm. The
rocks are black, the place is gloomy, imparting thereby a
surprising effect to the white rushing column of water. A beck
running down the hill finds its way into a crevice in the cliffs,
from which it leaps in one great fall of more than 80 feet, roaring
loudly. Look up: the chasm is so narrow that the trees and bushes
overhang and meet overhead; and what with the subdued light and
mixture of crags and verdure, and the impressive aspect of the
place altogether, you will be lost in admiration.
"To descend lower seems scarcely possible, but you do get down,
scrambling over the big stones to the very bottom, into the
swirling shower of spray. Here a deep recess, or chamber, at one
side, about eight feet in height, affords good standing ground,
whence you may see that the water is swallowed up at once, and
disappears in the heap of pebbles on which it falls."
In the Wombeyan Caves, near Taralga, in this colony (New South Wales),
there is a similar phenomenon. The mountain in which the caves are
formed dams, at right angles, a valley of considerable length. On the
one side a creek flows into a hole underneath the "Wombeyan Church"--a
name given to the principal entrance. This shallow hole is filled with
large boulders and less bulky water-worn stones, through which the water
instantly filters and disappears. The suction is perceptible if a hand
or foot be placed in the basin. On the other side of the mountain the
water, running at a considerable distance below the surface, can be seen
through an orifice. Farther on, about three-quarters of a mile from the
mountain side, the stream bubbles up like a fountain, and reminds the
visitor of antique pictures representing the rush of water from
rock-smitten Horeb.
The most gigantic of underground river wonders are to be found in the
Mammoth Cave of Kentucky, where the Echo River is navigable for
three-quarters of a mile, where the Roaring River raises its liquid
voice, where Lake Lethe soothes to forgetfulness, and where there is a
veritable Styx with a nineteenth century Charon. But although everything
about that cave is colossal, it cannot surpass Jenolan in its deep
emotional effects, or in the admiration it evokes. Indeed, in these
respects an American visitor, familiar with the Mammoth Cave, has given
the palm to Jenolan.
Having descended the 50-feet ladder, the foot of which is clamped to a
bare rock, the excursionist watches the guide hopping gleefully down,
with candles in one hand and paraphernalia in the other. He then peers
into the darkness to find the river, and is led along a gradual slope of
about ten feet, when he comes to its margin without recognising it, and
would possibly soon be up to his knees in it if he were not warned by
his cicerone. It is apparently motionless, as smooth as a mirror, and so
clear that at first it is difficult to believe there is any water there
at all. You see the sand and pebbles and rocks at the bottom, but do not
perceive the fluid which covers them.
The river is about 10 feet wide, and from 12 to 18 inches deep. The
length visible is about 60 yards. The overhanging rocks range from 5 or
6 feet to 70 feet in height. From one end of the river comes a sweet
soothing sound, made by water-friction. This proves the existence of a
considerable current, but the fluid is so limpid and smooth that the eye
cannot detect its motion. It is demonstrated, however, in another way.
The curator cuts little sections of sperm candle, and, after lighting
the wick, floats them on the river, whereupon they immediately begin to
glide down the stream, the course of which is nearly south-east. The
effect is extremely pretty. Not only are the lights themselves sharply
mirrored below, but there is a perfect reflection of the rocks above.
Near the tunnel by which the water emerges N.N.W. is a mass of
overhanging formation, duplicated in a natural mirror. The bed of the
watercourse is dark, being covered chiefly with mud and grit and a few
water-worn pebbles. The rocky walls are of limestone--white and black.
Up the channel N.W., about 40 yards, is a good crossing-place--not in
old Charon's boat, but by means of an ordinary deal plank. On the other
side of the river is a ledge of rocks with pebble drift concreted with a
substance somewhat resembling the cement in which diamonds are found,
and the pebbles, although larger, are of the same shape and blackness as
those commonly associated with the luminous gems found in their natural
state at Kimberley, in South Africa, or in the Tenterfield district of
New South Wales.
On turning the light of the magnesium lamp up the river, its rocky
ledges are seen to be ornamented with stalactites and formation
perfectly mirrored in the water, which is about 600 feet from the
surface, and about 50 below the level of the Cave House in the centre of
the valley. Never had river more romantic barriers. Human imagination
could not conceive a freak of nature more wildly grand or mysteriously
beautiful. There are large ornamented pillars near delicately-tinted
formation, drooping from overhanging rocks, like pensile boughs of
weeping willow. Some of the twigs skim the surface of the stream, and
others are bathed in it. Beyond is a water-hole about 40 feet long, and
from 16 to 20 feet wide. Because of its wonderful clearness, it is
difficult to judge of its depth; but it has been tested to the extent of
five feet, and probably at the extreme point where the water flows from
the tunnel it may be six or seven feet deep. The effect of the brilliant
light is superb. The ornamentation on the roof of the tunnel is
reflected and transposed in the mirror below, each reflected stalactite
having the appearance of a twin stalagmite rising from the river bed,
which may be traversed for about 150 yards.
Nearly six months ago the caretaker placed in this river twenty young
carp from Bathurst. Some of them were enticed from their cavernous
resting-places by the bright rays of the lamp, and appeared to be
tolerably vivacious and in fair condition. They seem to have all they
require except the solar rays; but what is life without sunshine! They
ought to be scientifically observed, for there is a theory that in
three generations of darkness they will become blind. This has been the
fate of the fishes in the Mammoth Cave of Kentucky, and it is stated
that their blindness is the result of a law of Nature, which does not
continue to supply organs or powers which have ceased to be necessary.
Dr. Forwood, in his history of the Mammoth Cave, says:--"The fishes are
of a peculiar species, and are of a class known as viviparous, which
give birth to their young alive, and do not deposit eggs after the
manner of most other fishes. They have rudiments of eyes, but no optic
nerve, and are, therefore, incapable of being affected by any degree of
light.... It has been proved that these eyeless fishes prey upon each
other. In shape they somewhat resemble the common catfish, and rarely
exceed eight inches in length." Professor Silliman published the
following in his "Journal" for May 1851:--"Of the fish there are two
species, one of which has been described by Dr. Wyman in the _American
Journal of Science_, and which is entirely eyeless. The second species
of the fish is not colourless like the first, and it has external eyes,
which, however, are found to be quite blind. The crawfish, or small
crustacea, inhabiting the rivers with fish are also eyeless and
uncoloured; but the larger-eyed and coloured crawfish, which are
abundant within the caves, are also common at some seasons in the
subterranean rivers, and so also, it is said, the fish of the Green
River are to be found in times of flood in the rivers of the Caves." Dr.
Forwood gives also the following quotations, on the authority of
Professor Agassiz, an eminent naturalist in the department of
ichthyology:--
"The blind fish of the Mammoth Cave was for the first time
described in 1842 in the 'Zoology of New York,' by Dr. Dekay, part
3rd, page 187, under the name of 'Amblyopsis spelaeus,' and
referred, with doubt, to the family of 'Siluridae,' on account of a
remote resemblance to my genus Cetopsis. Dr. J. Wyman has published
a more minute description of it, with very interesting anatomical
details, in vol. xlv. of the 'American Journal of Science and
Arts,' 1843, page 94.
"In 1844, Dr. Tellkampf published a more extended description, with
figures, in 'Mueller's Archiv' for 1844, and mentioned several other
animals found also in the Cave, among which the most interesting is
the crustacean which he calls 'Astacus pellucidus,' already
mentioned, but not described, by Mr. Thompson, President of the
Natural History Society of Belfast. Both Thompson and Tellkampf
speak of eyes in these species, but they are mistaken. I have
examined several specimens and satisfied myself that the peduncle
of the eye only exists; but there are no visible facets at its
extremity, as in other crawfish.
"Mr. Thompson mentions, further, crickets, allied to 'Phalangopsis
longipes,' of which Tellkampf says that it occurs throughout the
Cave. Of spiders, Dr. Tellkampf found two eyeless, small white
species, which he calls 'Phalangodes armata' and 'Anthrobia
monmouthia'; flies, of the genus 'Anthomyia'; a minute shrimp,
called by him 'Triura cavernicola'; and two blind beetles;
'Anophthalmus tellkampfii' of Erichson, and 'Adelops hirtus;' of
most of which Dr. Tellkampf has published a full description, and
figures in a subsequent paper, inserted in Erichson's 'Archiv,'
1844, p. 318.
"The infusoria observed in the Cave resemble 'Monas Kolpoda,'
'Monas socialis,' and 'Bodo intestinalis,'--a new Chilomonas, which
he calls 'Ch. emarginata,' and a species allied to 'Kolpoda
cucullus.'
"As already mentioned, Dekay has referred the blind fish, with
doubt, to the family of Siluridae. Dr. Tellkampf, however,
establishes for it a distinct family. Dr. Storer, in his 'Synopsis
of the Fishes of North America,' published in 1846, in the 'Memoirs
of the American Academy of Arts and Sciences,' is also of opinion
that it should constitute a distinct family, to which he gives the
new name of 'Hypsaeidae,' page 435. From the circumstance of its
being viviparous, from the character of its scales, and from the
form and structure of its head, I am inclined to consider this fish
as an aberrant type of my family of Cyprinodonts."
The effect of long-continued darkness upon visual organs has had some
remarkable illustrations. At one time an idea prevailed in America that
caves possessed certain curative properties, and afflicted people
remained in them; but the absence of light proved disastrous to many. It
is recorded that those patients "who remained in the cave three or four
months presented a frightful appearance. The face was entirely
bloodless, eyes sunken, and pupils dilated to such a degree that the
iris ceased to be visible, so that, no matter what the original colour
of the eye might have been, it soon appeared black."
This subterranean river offers a fine opportunity for scientific
observation well worthy to be embraced by some Australian naturalist. In
the vicinity of the river is to be noticed one of the few signs of decay
to be found in the caves--a portion of shell pattern formation shows
evidence of mouldering, and appears like a mere skeleton. When the
visitor has ascended the ladder and safely negotiated the angle at the
top, he feels that he has witnessed the most interesting place to be
found in the western wonderland; and when he fishes for a compliment to
his agility, and is reminded of the graceful forms that occasionally
ascend and descend in much better style, he immediately recalls a
Patriarch's dream, and thinks the ladder ought to be named after Jacob.