ICE-CAVES
OF
FRANCE AND SWITZERLAND.
A NARRATIVE OF
SUBTERRANEAN EXPLORATION.
BY THE
REV. G.F. BROWNE, M.A.
FELLOW AND ASSISTANT TUTOR OF ST. CATHARINE'S COLLEGE, CAMBRIDGE;
MEMBER OF THE ALPINE CLUB.
1865.
PREFACE.
The existence of natural ice-caves at depths varying from 50 to 200 feet
below the surface of the earth, unconnected with glaciers or snow
mountains, and in latitudes and at altitudes where ice could not under
ordinary circumstances be supposed to exist, has attracted some
attention on the Continent; but little or nothing seems to be
practically known in England on the subject. These caves are so
singular, and many of them so well repay inspection, that a description
of the twelve which I have visited can scarcely, as it seems to me, be
considered an uncalled-for addition to the numerous books of travel
which are constantly appearing. In order to prevent my narrative from
being a mere dry record of natural phenomena, I have interspersed it
with such incidents of travel as may be interesting in themselves or
useful to those who are inclined to follow my steps. I have also given,
from various sources, accounts of similar caves in different parts of
the world.
A pamphlet on _Glacières Naturelles_ by M. Thury, of Geneva, of the
existence of which I was not aware when I commenced my explorations, has
been of great service to me. M. Thury had only visited three glacières
when he published his pamphlet in 1861, but the observations he records
are very valuable. He had attempted to visit a fourth, when,
unfortunately, the want of a ladder of sufficient length stopped him.
I was allowed to read Papers before the British Association at Bath
(1864), in the Chemical Section, on the prismatic formation of the ice
in these caves, and in the Geological Section, on their general
character and the possible causes of their existence.
It is necessary to say, with regard to the sections given in this book,
that, while the proportions of the masses of ice are in accordance with
measurements taken on the spot, the interior height of many of the
caves, and the curves of the roof and sides, are put in with a free
hand, some of them from memory. And of the measurements, too, it is only
fair to say that they were taken for the most part under very
unfavourable circumstances, in dark caves lighted by one, or sometimes
by two candles, with a temperature varying from slightly above to
slightly below the freezing-point, and with no surer foot-hold than that
afforded by slippery slopes of ice and chaotic blocks of stone. In all
cases, errors are due to want of skill, not of honesty; and I hope that
they do not generally lie on the side of exaggeration.
CAMBRIDGE: _June_ 1865.
CONTENTS.
CHAPTER I. PAGE
THE GLACIÈRE OF LA GENOLLIÈRE, IN THE JURA .............1
CHAPTER II.
THE GLACIÈRE OF S. GEORGES, IN THE JURA ................19
CHAPTER III.
THE LOWER GLACIÈRE OF THE PRÉ DE S. LIVRES, IN
THE JURA ...............................................32
CHAPTER IV.
THE UPPER GLACIÈRE OF THE PRÉ DE S. LIVRES .............46
CHAPTER V.
THE GLACIÈRE OF GRÂCE-DIEU, OR LA BAUME, NEAR BESANÇON,
IN THE VOSGIAN JURA ....................................60
CHAPTER VI.
BESANÇON AND DÔLE ......................................85
CHAPTER VII.
THE GLACIÈRE OF MONTHÉZY, IN THE VAL DE TRAVERS ........97
CHAPTER VIII.
THE GLACIÈRE AND NEIGIÈRE OF ARC-SOUS-CICON ............118
CHAPTER IX.
THE SCHAFLOCH, OR TROU-AUX-MOUTONS, NEAR THE LAKE OF
THUN ...................................................131
CHAPTER X.
THE GLACIÈRE OF GRAND ANU, NEAR ANNECY .................157
CHAPTER XI.
THE GLACIÈRE OF CHAPPET-SUR-VILLAZ, NEAR ANNECY ........182
CHAPTER XII.
THE GLACIÈRES OF THE BREZON, AND THE VALLEY
OF REPOSOIR ............................................202
CHAPTER XIII.
LA BORNA DE LA GLACE, IN THE DUCHY OF AOSTA ............210
CHAPTER XIV.
THE GLACIÈRE OF FONDEURLE, IN DAUPHINÉ .................212
CHAPTER XV.
OTHER ICE-CAVES:--
THE CAVE OF SCELICZE, IN HUNGARY .....................237
THE CAVE OF YEERMALIK, IN KOONDOOZ ...................240
THE SURTSHELLIR, IN ICELAND ..........................244
THE GYPSUM CAVE OF ILLETZKAYA ZASTCHITA, ORENBURG ....249
THE ICE-CAVERN ON THE PEAK OF TENERIFFE ..............253
CHAPTER XVI.
BRIEF NOTICES OF VARIOUS ICE-CAVES .....................256
CHAPTER XVII.
HISTORY OF THEORIES RESPECTING THE CAUSES OF
SUBTERRANEAN ICE .......................................282
CHAPTER XVIII.
ON THE PRISMATIC STRUCTURE OF THE ICE IN GLACIÈRES .....300
CHAPTER XIX.
ON THE MEAN TEMPERATURE OF THE REGIONS IN WHICH
SOME OF THE GLACIÈRES OCCUR ............................308
APPENDIX ...............................................313
LIST OF ILLUSTRATIONS.
ICE-COLUMNS IN THE GLACIÈRE OF LA GENOLLIÈRE ...........6
ENTRANCE TO THE GLACIÈRE OF S. GEORGES .................24
VERTICAL SECTIONS OF THE GLACIÈRE OF S. GEORGES ........26
LOWER GLACIÈRE OF THE PRÉ DE S. LIVRES .................39
SECTION OF THE LOWER GLACIÈRE OF THE
PRÉ DE S. LIVRES .......................................41
SECOND CAVE OF THE UPPER GLACIÈRE OF THE PRÉ DE
S. LIVRES ..............................................50
VERTICAL SECTIONS OF THE UPPER GLACIÈRE OF THE PRÉ
DE S. LIVRES ...........................................52
VERTICAL SECTION OF THE GLACIÈRE OF GRÂCE-DIEU, NEAR
BESANÇON ...............................................77
BATH IN THE DOUBS, AT BESANÇON .........................91
VERTICAL SECTION OF THE GLACIÈRE OF MONTHÉZY, IN THE
VAL DE TRAVERS .........................................108
GROUND PLAN OF THE GLACIÈRE OF MONTHÉZY ................110
VERTICAL SECTION OF THE GLACIÈRE OF GRAND ANU, NEAR
ANNECY .................................................173
ICE-CAVE IN THE SURTSHELLIR ............................248
* * * * *
CHAPTER I.
THE GLACIÈRE OF LA GENOLLIÈRE, IN THE JURA.
In the summer of 1861, I found myself, with some members of my family,
in a small rustic _pension_ in the village of Arzier, one of the highest
villages of the pleasant slope by which the Jura passes down to the Lake
of Geneva. The son of the house was an intelligent man, with a good
knowledge of the natural curiosities which abound in that remarkable
range of hills, and under his guidance we saw many strange things. More
than once, he spoke of the existence of a _glacière_ at no great
distance, and talked of taking us to see it; but we were sceptical on
the subject, imagining that _glacière_ was his patois for _glacier_, and
knowing that anything of the glacier kind was out of the question. At
last, however, on a hot day in August, we set off with him, armed, at
his request, with candles; and, after two or three hours of pine
forests, and grass glades, and imaginary paths up rocky ranges of hill
towards the summits of the Jura, we came to a deep natural pit, down the
side of which we scrambled. At the bottom, after penetrating a few yards
into a chasm in the rock, we discovered a small low cave, perfectly
dark, with a flooring of ice, and a pillar of the same material in the
form of a headless woman, one of whose shoulders we eventually carried
off, to regale our parched friends at Arzier. We lighted up the cave
with candles, and sat crouched on the ice drinking our wine, finding
water, which served the double purpose of icing and diluting the wine,
in small basins in the floor of ice, formed apparently by drops falling
from the roof of the cave.
A few days after, our guide and companion took us to an ice-cavern on a
larger scale, which, we were told, supplies Geneva with ice when the
ordinary stores of that town fail; and the next year my sisters went to
yet another, where, however, they did not reach the ice, as the ladder
necessary for the final drop was not forthcoming.
In the course of the last year or two, I have mentioned these glacières
now and then in England, and no one has seemed to know anything about
them; so I determined, in the spring of 1864, to spend a part of the
summer in examining the three we had already seen or heard of, and
discovering, if possible, the existence of similar caves.
The first that came under my notice was the Glacière of La Genollière;
and, though it is smaller and less interesting than most of those which
I afterwards visited, many of its general features are merely reproduced
on a larger scale in them. I shall therefore commence with this cave,
and proceed with the account of my explorations in their natural order.
It is probable that some of the earlier details may seem to be somewhat
tedious, but they are necessary for a proper understanding of the
subject.
La Genollière is the _montagne_, or mountain pasturage and wood,
belonging to the village of Genollier, an ancient priory of the monks of
S. Claude.[1] The cave itself lies at no great distance from Arzier--a
village which may be seen in profile from the Grand Quai of Geneva,
ambitiously climbing towards the summit of the last slope of the Jura.
To reach the cave from Geneva, it would be necessary to take train or
steamer to Nyon, whence an early omnibus runs to S. Cergues, if crawling
up the serpentine road can be called running; and from S. Cergues a
guide must be taken across the Fruitière de Nyon, if anyone can be found
who knows the way. From Arzier, however, which is nine miles up from
Nyon, it was not necessary to take the S. Cergues route; and we went
straight through the woods, past the site of an old convent and its
drained fish-pond, and up the various rocky ridges of hill, with no
guide beyond the recollection of the previous visits two and three years
before, and a sort of idea that we must go north-west. As it was not yet
July, the cows had not made their summer move to the higher châlets, and
we found the mountains uninhabited and still.
The point to be made for is the upper Châlet of La Genollière, called by
some of the people _La Baronne_, [2] though the district map puts La
Baronne at some distance from the site of the glacière. We had some
difficulty in finding the châlet, and were obliged to spread out now and
then, that each might hunt a specified portion of the wood or glade for
signs to guide our further advance, enjoying meanwhile the lilies of the
mountain and lilies of the valley, and fixing upon curious trees and
plants as landmarks for our return. In crossing the last grass, we found
the earliest vanilla orchis (_Orchis nigra_) of the year, and came upon
beds of moonwort (_Botrychium Lunaria_) of so unusual a size that our
progress ceased till such time as the finest specimens were secured.
Some time before reaching this point, we caught a glimpse of a dark
speck on the highest summit in sight, which recalled pleasantly a night
we had spent there three years before for the purpose of seeing the sun
rise.[3] My sisters had revisited the Châlet des Chèvres, which this
dark speck represented, in 1862, and found that the small chamber in
which we had slept on planks and logs had become a more total ruin than
before, in the course of the winter, so that it is now utterly
untenable.
From Arzier to the Châlet of La Genollière, would be about two hours,
for a man walking and mounting quickly, and never losing the way; and
the glacière lies a few minutes farther to the north-west, at an
elevation of about 2,800 feet above the lake, or 4,000 feet above the
sea.[4] A rough mountain road, leading over an undulating expanse of
grass, passes narrowly between two small clumps of trees, each
surrounded by a low circular wall, the longer diameter of the
enclosure on the south side of the road being 60 feet. In this
enclosure is a natural pit, of which the north side is a sheer rock,
of the ordinary limestone of the Jura, with a chasm almost from the
top; while the south side is less steep, and affords the means of
scrambling down to the bottom, where a cave is found at the foot of
the chasm, passing under the road. The floor of this small but
comparatively lofty cave is 52 feet below the surface of the earth,
and slopes away rapidly to the west, where, by the help of candles,
the rock which forms the wall is seen to stop short of the floor,
leaving an entrance 2 or 3 feet high to an inner cave--the glacière.
The roof of this inner cave rises slightly, and its floor falls, so
that there is a height of about 6 feet inside, excepting where a large
open fissure in the roof passes high up towards the world above. At
one end, neither the roof nor the floor slopes much, and in this part
of the cave the height is less than 3 feet.
It would be very imprudent to go straight into an ice-cave after a long
walk on a hot summer's day, so we prepared to dine under the shade of
the trees at the edge of the pit, and I went down into the cave for a
few moments to get a piece of ice for our wine. My first impression was
that the glacière was entirely destroyed, for the outer cave was a mere
chaos of rock and stones; but, on further investigation, it turned out
that the ruin had not reached the inner cave. In our previous visit we
had noticed a natural basin of some size and depth among the trees on
the north side of the road, and we now found that the chaos was the
result of a recent falling-in of this basin; so that from the bottom of
the first cave, standing as it were under the road, we could see
daylight through the newly-formed hole.
The total length of the floor of the inner cave, which lies north-east
and south-west, is 51 feet; and of this floor a length of about 37 feet
was more or less covered with ice, the greatest breadth of the ice being
within an inch or two of 11 feet. Excepting in the part of the cave
already mentioned as being less than 3 feet high, we found the floor not
nearly so dry, nor so completely covered with ice, as when we first saw
the glacière, three years before, in the middle of an exceptionally hot
August. Under the low roof all was very dry, though even there the ice
had not an average thickness of more than 8 inches. It may be as well to
say, once for all, that the ice in these caves is never found in a sheet
on a pool of water; it is always solid, forming the floor of the cave,
filling up the interstices of the loose stones, and rising above them,
in this case with a surface perfectly level.
[Illustration: ICE-COLUMNS IN THE GLACIÈRE OF LA GENOLLIÈRE.]
We found four principal columns of ice, three of which, in the loftiest
part of the cave, are represented in the accompanying engraving: I call
them three, and not two, because the two which unite in a common base
proceeded from different fissures. The line of light at the foot of the
rock-wall is the only entrance to the glacière. The lowest column was
11-2/3 feet high and 1-2/3 feet broad, not more than 6 inches thick in
the middle, half-way up, and flattened symmetrically so as to be
comparatively sharp at the edges, like a huge double-edged sword. It
stood clear of the rock through its whole height, but scarcely left room
between itself and the wall of the cave for a candle to be passed up and
down. The other two columns shown in the engraving poured out of
fissures in the rock, streaming down as cascades, the one being 13-1/2
and the other 15 feet high; and when we tied a candle to the end of an
alpenstock, and passed it into the fissures, we found that the bend of
the fissures prevented our seeing the termination of the ice. An
intermittent disturbance of the air in these fissures made the flame
flicker at intervals, though generally the candle burned steadily in
them, and we could detect no current in the cave. The fourth column was
in the low part of the cave, and we were obliged to grovel on the ice to
get its dimensions: it was 3-1/4 feet broad and 4-1/3 feet high, the
roof of the cave being only 2-3/4 feet high; and it poured out of the
vertical fissure like a smooth round fall of water, adhering lightly to
the rock at its upper end like a fungus, and growing out suddenly in its
full size. This column was dry, whereas on the others there were
abundant symptoms of moisture, as if small quantities of water were
trickling down them from their fissures, though the fissures themselves
appeared to be perfectly dry.
In one of the fissures there was a patch of what is known as
sweating-stone, [5] with globules of water oozing out, and standing
roundly upon it: the globules were not frozen. This stone was
exceedingly hard, and defied all our efforts to break off a specimen,
but at last we got two small pieces, hard and heavy, and wrapped them
in paper; ten weeks after, we found them of course quite dry, and
broke them easily, small as they were, with our fingers. The fissure
from which the shortest of the four columns came was full of gnats, as
were also several crevices in the walls of the cave, especially in the
lowest part; and we found a number of large red-brown flies, [6]
nearly an inch long, running rapidly on the ice and stones, after the
fashion of the flies with which trout love best to be taken. The
central parts of the cave, where the roof is high, were in a state
provincially known as 'sloppy,' and drops of water fell now and then
from above, either splashing on wet stones, or hollowing out basins in
the remaining ice, or, sometimes, shrewdly detecting the most
sensitive spot in the back of the human neck. We placed one of
Casella's thermometers on a piece of wood on one of the wet stones,
clear of the ice, and it soon fell to 34°. Probably the temperature
had been somewhat raised by the continued presence of three human
beings and two lighted candles in the small cavern; and, at any rate,
the cold of two degrees above freezing was something very real on a
hot summer's day, and told considerably upon my sisters, so that we
were compelled to beat a retreat,--not quite in time, for one of our
party could not effect a thaw, even by stamping about violently in the
full afternoon sun.
While we were in the cave, we noticed that the surfaces of the columns
were covered by very irregular lines, marked somewhat deeply in the
ice, and dividing the surface into areas of all shapes, a sort of
network, with meshes of many different shapes and sizes. These areas
were smaller towards the edges of the columns; the lines containing
them were not, as a rule, straight lines, and almost baffled our
efforts to count them, but, to the best of my belief, there were
meshes with three, four, and up to eight sides. The column which
stood clear of the rock was composed of very limpid ice, without
admixture of air; but the cascades were interpenetrated by veins of
looser white ice, and, where the white ice came, the surface lines
seemed to disappear. As we sat on the grass outside, arranging our
properties for departure, my attention was arrested by the columnar
appearance of the fractured edge of the block of ice which we had used
at luncheon. It was about 5 inches thick, and had formed part of a
stalagmite whose horizontal section, like that of the free column,
would be an ellipse of considerable eccentricity; and, on examination,
it turned out that the surface areas, which varied in size from a
large thumb-nail to something very small, were the ends of prisms
reaching through to the other side of the piece of ice, at any rate in
the thinner parts, and presenting there similar faces. Not only so,
but the prisms could be detached with great ease, by using no
instrument more violent than the fingers; while the point of a thin
knife entered freely at any of the surface lines, and split the ice
neatly down the sides of the prisms. When one or two of the sides of a
prism were exposed, at the edge of the piece of ice, the prism could
be pushed out entire, like a knot from the edge of a piece of wood. In
some cases there seemed to be capillary fissures coincident with the
lines where several sides of prisms met. Considering the shape of the
whole column, it is clear that the two ends of each prism could not be
parallel; neither was one of the ends perfectly symmetrical with the
other, and I do not think that the prisms were of the nature of
truncated pyramids. On descending again, I found that the columns
were without exception formed of this prismatic ice, either in whole,
as in the clear column, or in part, as where limpid prisms existed
among the white ice which ran in veins down the cascades. In the free
vertical column the prisms seemed to be deposited horizontally, and in
the thicker parts they did not pass clear through. We carried a large
piece of ice down to Arzier in a botanical tin, and on our arrival
there we found that all traces of external lines had disappeared.
This visit to the glacière was on Saturday, and on the following Monday
I determined to go up alone, to take a registering thermometer, and
leave it in the cave for the night; which, of course, would entail a
third visit on the next day. Monday brought a steady penetrating rain,
of that peculiar character which six Scotch springs had taught me to
describe as 'just a bit must;' while in the higher regions the fog was
so hopeless, that a sudden lift of the mist revealed the unpleasant fact
that considerable progress had been made in a westerly direction, the
true line being north-west. Instead of the rocks of La Genollière, the
foreground presented was the base of the Dôle, and the chasm which
affords a passage from the well-known fortress of Les Rousses into Vaud.
There was nothing for it but to turn in the right direction, or attempt
to do so, and force a way through the wet woods till something should
turn up. This something took the form of a châlet; but no amount of
hammering and shouting produced any response, and it was only after a
forcible entrance, and a prolonged course of interior shouting, that a
man was at length drawn. He said that he had been asleep--and why he
put it in a past tense is still a mystery--and could give no idea of
the direction of the châlet on La Genollière, beyond a vague suggestion
that it was somewhere in the mist; a suggestion by no means improbable,
seeing that the mist was ubiquitous. One piece of information he was
able to give, and it was consoling: I was now, it seemed, on the
Fruitière de Nyon, and therefore the desired châlet could not be far
off, if only a guide could be found. On the whole, he thought that a
guide could not be found; but there were men in the châlet, and I might
go up the ladder with him and see what could be done. He led to a
chamber with a window of one small pane, dating apparently from the
first invention of glass, and never cleaned since. An invisible corner
of the room was appealed to; but the voice which resided there, and
seemed like everything else to be asleep, pleaded dreamily a total
ignorance of the whereabouts of the châlet in question. Just as, by dint
of steady staring through the darkness, an indistinct form of a
mattress, with a human being reclining thereon, began to be visible,
another dark corner announced that this new speaker had heard of a
_p'tit sentier_ leading to the châlet, but knew neither direction nor
distance. Here the space between the two corners put in a word; and, as
the darkness was now becoming natural, seven or eight mattresses
appeared, ranged round the room, some holding one, some two men, most of
whom were sitting up on end with old caps on, displaying every variety
of squalor. The voice which had spoken last declared that the distance
was three-quarters of an hour, and that if the day were clear there
would be no difficulty in reaching the châlet; as it was, the man would
be very glad to try.
A change of cap was the only dressing necessary for the volunteer, and
we faced the fog and rain, which elicited from him such a disgraceful
amount of swearing, that it was on all accounts well when the rain
ceased for a few minutes, the mists rolled off, and the clouds lifted
sufficiently to betray the surface of the Lake of Geneva, luxuriating in
the clear warmth of an early summer's day, and making us shiver by the
painful contrast which our own altitude presented. The deep blue of the
lake brought to mind the story of the shepherd of Gessenay (Saanen), of
whom it is told that when he was passing the hills with some friends for
a first visit to Vevey, and came in sight of the lake, which he had
never seen before, he turned and hurried home incontinent, declaring
that he would not enter a country where the good God had made the blue
sky to fall and fill the valleys.
In this bright interval we came upon a magnificent fox, and the
peasant's impulse was, 'Oh, for a good gun!' an exclamation which would
have sounded horrible to English ears, if I had not been previously
broken in to it by an invitation from a Scotch gamekeeper to a fox-hunt,
when he promised an excellent gun, and a _stance_ which the foxes were
sure to pass.
The rain now came on again, and the guide thought he had had plenty of
it, and must return for the afternoon milking; and just then, as good
luck would have it, we stumbled upon an immense clump of nettles which
had been one of our landmarks two days before, so that he was no longer
necessary, and we said affectionate adieux.
The glacière was in a state of ruin. Only the right-hand column, not
speaking heraldically, was standing, the others lying in blocks frozen
hard together on the ground. The column which still stood was much
shrunken, and seemed too small for its fissure, the sides of which it
scarcely touched. The wind blew down the entrance slope so
determinedly, that a candle found it difficult to live at the bottom
of the first cave; and a portion of the current blew into the
glacière, and in its sweep exactly struck the fallen columns, the
edges of which were already rounded by thaw. Much of this must be
attributed to the recent opening of the second shaft (p. 5), which
admits a thorough draught through the first cave, and so exposes the
glacière to currents of warmer air; and I should expect to find that
in future the ice will disappear from that part of the cave every
summer, [7] whereas in 1861 we found it thick and dry (excepting a few
small basins containing water) and evidently permanent, in the middle
of a very hot August. The low part of the cave was so completely
protected from the current, that the candle burned there quite
steadily for an hour and a half: still, like the others, the column at
that end of the glacière was broken down, and it therefore became
necessary to attribute its fall to some other agency than the current
of external air. There had been a very large amount of rain, and the
surface of the rock in the fissures was evidently wet; so I have no
doubt that the filtering through of the warm rain-water had thawed the
upper supports of the ice-cascades, and then, owing to their slightly
inclined position, the pedestal had not provided sufficient support,
and so they had fallen. One of them, perhaps, had brought down in its
fall the free column, which had stood two days before on its own base,
without any support from the rock. Very probably, too--indeed, almost
certainly,--the fall of the large mass of rock, which once formed the
bottom of the basin on the north side of the road, has affected the
old-established fissures, by which rain-water has been accustomed to
penetrate in small quantities to the glacière, so that now a much
larger amount is admitted. On this account, there will probably be a
great diminution of the ice in the course of future summers, though
the amount formed each winter may be greater than it has hitherto
been. Constant examination of other columns and fissures has convinced
me, that, before the end of autumn, the majority of the glacières will
have lost all the columns which depend upon the roof for a part of
their support, or spring from fissures in the wall; whereas those
which are true stalagmites, and are self-supporting, will have a much
better chance of remaining through the warm season, and lasting till
the winter, and so increasing in size from year to year. Free
stalagmites, however, which are formed under fissures capable of
pouring down a large amount of water on the occasion of a great flood
of rain, must succumb in time, though not so soon as the supported
columns.
A curious appearance was presented by a small free stalagmite in the
retired part of the cave. The surface of the stalagmite was wet, from
the drops proceeding from a fissure above, and was lightly covered in
many parts with a calcareous deposit, brought down from the fissures in
the roof by the water filtering through. The stalagmite was of the
double-edged-sword shape, and the limestone deposit collected chiefly at
one of its edges, the edge nearer to that part of the cave where thaw
prevailed; so that the real edge was a ridge of deposit beyond the edge
of the ice.[8] Patches of limestone paste lay on many parts of the
ice-floor.
In the loftier part of the cave, water dropped from the roof to so
large an extent, that ninety-six drops of water in a minute splashed
on to a small stone immediately under the main fissure. This stone was
in the centre of a considerable area of the floor which was clear of
ice; and it struck me that if the columns were formed by the freezing
of water dropping from the roof, there ought to have been at some time
a large column under this, the most plentiful source of water in the
cave. Accordingly, I found that the edge of the ice round this clear
area was much thicker than the rest of the ice of the floor, and was
evidently the remains of the swelling pedestal of a column which had
been about 12 feet in circumference. This departed column may account
for a fact which I discovered in another glacière, and found to be of
very common occurrence, viz., that in large stalagmites there is a
considerable internal cavity, extending some feet up from the ground,
and affording room even for a man to walk about inside the column.
When the melted snows of spring send down to the cave, through the
fissures of the rock, an abundance of water at a very low
temperature, and the cave itself is stored with the winter's cold,
these thicker rings of ice catch first the descending water, and so a
circular wall, naturally conical, is formed round the area of stones;
the remaining water either running off through the interstices, or
forming a floor of ice of less thickness, which yields to the next
summer's drops. In the course of time, this conical wall rises,
narrowing always, till a dome-like roof is at length formed, and
thenceforth the column is solid. Of course, the interior cannot be
wholly free from ice; and it will be seen from the account of one of
these cavities, which I explored in the Schafloch, that they are
decked with ice precisely as might be expected.[9] Another possible
explanation of this curious and beautiful phenomenon will be given
hereafter.[10]
The temperature was half a degree lower than when there were three of us
in the cave two days before. I deposited one of Casella's registering
thermometers, on wood, on a stone in that part of the floor which was
free from ice, though there was ice all round it at some little
distance. The thermometer was well above the surface of the ice, and
was protected from chance drops of water from the roof.
The next morning I started early from Arzier, having an afternoon
journey in prospect to the neighbourhood of another glacière, and was
accompanied by Captain Douglas Smith, of the 4th Regiment. On our way to
La Genollière, we came across the man who had served as guide the day
before, and a short conversation respecting the glacière ensued. He had
only seen it once, many years before, and he held stoutly to the usual
belief of the peasantry, that the ice is formed in summer, and melts in
winter; a belief which everything I had then seen contradicted. His last
words as we parted were, '_Plus il fait chaud, plus ça gèle_;' and,
paradoxical as it may appear, I believe that some truth was concealed in
what he said, though not as he meant it. Considering that his ideas were
confined to his cattle and their requirements, and that water is often
very difficult to find in that part of the Jura, a _hot_ summer would
probably mean with him a _dry_ summer, that is, a summer which does not
send down much water to thaw the columns in the cave. Extra heat in the
air outside, at any season, does not, as experience of these caves
proves abundantly, produce very considerable disturbance of their low
temperature, and so summer water is a much worse enemy than extra summer
heat; and if the caves could be protected from water in the hot season,
the columns in them would know how to resist the possible--but very
small--increase of temperature due to the excess of heat of one summer
above another. And since the eye is most struck by the appearance of the
stalagmites and ice-cascades, it may well be that the peasants have seen
these standing at the end of an unusually hot and dry summer, and have
thence concluded that hot summers are the best time for the formation of
ice. Of course, at the beginning of the winter after a hot summer, there
will be on these terms a larger nucleus of ice; and so it will become
true that the hotter the year, the more ice there will be, both during
the summer itself and after the following winter.
The further process of the formation of ice will be this:--the colds of
early winter will freeze all the water that may be in the glacières from
the summer's thaw, in such caves as do not possess a drainage, and then
the frost will have nothing to occupy itself upon but the ice already
formed, for no water can descend from the frost-bound surface of the
earth.[11] As soon as the snow begins to melt to so great a degree that
the fissures are opened up once more, the extremely cold water resulting
therefrom will descend through the limestone into a cave perfectly dry,
and filled with an atmosphere many degrees below the freezing point,
whose frost-power eagerly lays hold of every drop of water which does
not make its escape in time by the drainage of the cave. Thus the spring
months will be the great time of the formation of ice, and also of the
raising of the temperature from some degrees below freezing to the more
temperate register at which I have generally found it, viz., rather
above than below 32°. Professor Tyndall very properly likens the
external atmosphere to a ratchet-wheel, from its property of allowing
the passage of hot rays down to the surface of the earth, and resisting
their return: it may equally be so described on other grounds, inasmuch
as the cold and heavy atmosphere will sink in the winter into the pits
which lead to glacières, and will refuse to be altogether displaced in
summer by anything short of solar radiation.
We found the one column of the previous day still standing, though
evidently in an unhappy state of decay. The sharpness of its edges was
wholly gone, and it was withered and contorted; there were two cracks
completely through it, dividing it into three pieces 4 or 5 feet long,
which were clearly on the point of coming down. Externally, the day was
fine and warm, and so we found the cave comparatively dry, only one drop
falling in a minute on to the stone where ninety-six had fallen in the
same time the day before. The thermometer registered 32° as the greatest
cold of the night, and still stood at that point when we took it up.
We spent some little time in exploring the neighbourhood of the pits, in
order to find, if possible, the outlet for the drainage, but the ground
did not fall away sufficiently for any source from so low an origin to
show itself. The search was suggested by what I remembered of the
Glacière of S. Georges three years before, where the people believe that
a small streamlet which issues from the bottom of a steep rock, some
distance off, owes its existence to the glacière.
FOOTNOTES:
[Footnote 1: In this neighbourhood, the _montagne_ of any _commune_ is
represented by the feminine form of the name of the village: thus,
_L'Arzière_ is the _montagne_ of Arzier, and _La Bassine_ of Bassin.
This has a curious effect in the case of some villages--such, for
instance, as S. Georges--one of the landmarks of the district between
the lakes of Joux and Geneva being the _Châlet de la S. Georges_, a
grammatical anomaly which puzzles a stranger descending the southernmost
slope of the Jura from the Asile de Marchairuz. This law of formation is
not universal; for the _montagnes_ of Rolle and S. Livres are called the
_Prè de Rolle_ and the _Prè de S. Livres_, while the _Fruitière de Nyon_
is the rich upland possession of the town of that name.]
[Footnote 2: Probably a relic of the time when the earlier Barons of
Coppet possessed this district. The families of Grandson, Lesdiguières,
and Dohna successively held the barony; and in later times the title _de
Coppet_ hid a name more widely known, for on the Châlet of _Les
Biolles_, some distance to the east of La Baronne, the name of _Auguste
de Staël de Holstein de Coppet_ is carved, after the fashion of Swiss
châlets. This was Madame de Staël's son, who built Biolles in 1817; it
was afterwards sold to the commune of Nyon, and finally purchased by
Arzier two or three years ago.]
[Footnote 3: 'Cornhill Magazine,' June 1863, 'How we slept at the Châlet
des Chèvres.']
[Footnote 4: This is only a guess, made from a comparison with the
ascertained heights of neighbouring points.]
[Footnote 5: The patois of Vaud has a prettier name for this kind of
stone--_le sex_ (or _scex) qui plliau_, the weeping-stone.]
[Footnote 6: I brought one of these to England, and am told that it is
the _Stenophylax hieroglyphicus_ of Stephens, or something very like
that fly.]
[Footnote 7: Since writing this, I have been told that some English
officers who visited the cave in the August of 1864 found no ice in any
part.]
[Footnote 8: See also p. 231.]
[Footnote 9: P. 145.]
[Footnote 10: P. 301.]
[Footnote 11: It is possible that the freezing of the surface may play a
curious part in the phenomena of the spring season in such caves.
Supposing the surface to be completely frost-bound, all atmospheric
pressure will be removed from the upper surface of the water in the long
fissures, and thus water may be held in suspension, in the centre of
large masses of fissured rock, during the winter months. The first
thorough thaw will have the same effect as the removal of the thumb from
the upper orifice in the case of the hand-shower-bath; and the water
thus rained down into the cave will have a temperature sufficiently high
to destroy some portion of the cold stored up by the descent of the
heavy atmosphere of winter, or at least to melt out the ice which may
have blocked up the lower ends of the fissures.]
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