ON THE SCULPTURE OF MOUNTAINS:--FIRST, THE LATERAL RANGES.
Sec. 1. Close beside the path by which travellers ascend the Montanvert
from the valley of Chamouni, on the right hand, where it first begins to
rise among the pines, there descends a small stream from the foot of the
granite peak known to the guides as the Aiguille Charmoz. It is
concealed from the traveller by a thicket of alder, and its murmur is
hardly heard, for it is one of the weakest streams of the valley. But it
is a constant stream; fed by a permanent though small glacier, and
continuing to flow even to the close of the summer, when more copious
torrents, depending only on the melting of the lower snows, have left
their beds "stony channels in the sun."
I suppose that my readers must be generally aware that glaciers are
masses of ice in slow motion, at the rate of from ten to twenty inches a
day, and that the stones which are caught between them and the rocks
over which they pass, or which are embedded in the ice and dragged along
by it over those rocks, are of course subjected to a crushing and
grinding power altogether unparalleled by any other force in constant
action. The dust to which these stones are reduced by the friction is
carried down by the streams which flow from the melting glacier, so that
the water which in the morning may be pure, owing what little strength
it has chiefly to the rock springs, is in the afternoon not only
increased in volume, but whitened with dissolved dust of granite, in
proportion to the heat of the preceding hours of the day, and to the
power and size of the glacier which feeds it.
Sec. 2. The long drought which took place in the autumn of the year 1854,
sealing every source of waters except these perpetual ones, left the
torrent of which I am speaking, and such others, in a state peculiarly
favorable to observance of their _least_ action on the mountains from
which they descend. They were entirely limited to their own ice
fountains, and the quantity of powdered rock which they brought down
was, of course, at its minimum, being nearly unmingled with any earth
derived from the dissolution of softer soil, or vegetable mould, by
rains.
At three in the afternoon, on a warm day in September, when the torrent
had reached its average maximum strength for the day, I filled an
ordinary Bordeaux wine-flask with the water where it was least turbid.
From this quart of water I obtained twenty-four grains of sand and
sediment, more or less fine. I cannot estimate the quantity of water in
the stream; but the runlet of it at which I filled the flask was giving
about two hundred bottles a minute, or rather more, carrying down
therefore about three quarters of a pound of powdered granite every
minute. This would be forty-five pounds an hour; but allowing for the
inferior power of the stream in the cooler periods of the day, and
taking into consideration, on the other side, its increased power in
rain, we may, I think, estimate its average hour's work at twenty-eight
or thirty pounds, or a hundred weight every four hours. By this
insignificant runlet, therefore, some four inches wide and four inches
deep, rather more than two tons of the substance of the Mont Blanc are
displaced, and carried down a certain distance every week; and as it is
only for three or four months that the flow of the stream is checked by
frost, we may certainly allow eighty tons for the mass which it annually
moves.
Sec. 3. It is not worth while to enter into any calculation of the relation
borne by this runlet to the great torrents which descend from the chain
of Mont Blanc into the valley of Chamouni. To call it the thousandth
part of the glacier waters, would give a ludicrous under-estimate of
their total power; but even so calling it, we should find for result
that eighty thousand tons of mountain must be yearly transformed into
drifted sand, and carried down a certain distance.[49] How much greater
than this is the actual quantity so transformed I cannot tell; but take
this quantity as certain, and consider that this represents merely the
results of the labor of the constant summer streams, utterly
irrespective of all sudden falls of stones and of masses of mountain (a
single thunderbolt will sometimes leave a scar on the flank of a soft
rock, looking like a trench for a railroad); and we shall then begin to
apprehend something of the operation of the great laws of change, which
are the conditions of all material existence, however apparently
enduring. The hills, which, as compared with living beings, seem
"everlasting," are, in truth, as perishing as they: its veins of flowing
fountain weary the mountain heart, as the crimson pulse does ours; the
natural force of the iron crag is abated in its appointed time, like the
strength of the sinews in a human old age; and it is but the lapse of
the longer years of decay which, in the sight of its Creator,
distinguishes the mountain range from the moth and the worm.
Sec. 4. And hence two questions arise of the deepest interest. From what
first created forms were the mountains brought into their present
condition? into what forms will they change in the course of ages? Was
the world anciently in a more or less perfect state than it is now? was
it less or more fitted for the habitation of the human race? and are the
changes which it is now undergoing favorable to that race or not? The
present conformation of the earth appears dictated, as has been shown in
the preceding chapters, by supreme wisdom and kindness. And yet its
former state must have been different from what it is now; as its
present one from that which it must assume hereafter. Is this,
therefore, the earth's prime into which we are born; or is it, with all
its beauty, only the wreck of Paradise?
I cannot entangle the reader in the intricacy of the inquiries necessary
for anything like a satisfactory solution of these questions. But, were
he to engage in such inquiries, their result would be his strong
conviction of the earth's having been brought from a state in which it
was utterly uninhabitable into one fitted for man;--of its having been,
when first inhabitable, more beautiful than it is now; and of its
gradually tending to still greater inferiority of aspect, and unfitness
for abode.
It has, indeed, been the endeavor of some geologists to prove that
destruction and renovation are continually proceeding simultaneously in
mountains as well as in organic creatures; that while existing eminences
are being slowly lowered, others, in order to supply their place, are
being slowly elevated; and that what is lost in beauty or healthiness in
one spot is gained in another. But I cannot assent to such a conclusion.
Evidence altogether incontrovertible points to a state of the earth in
which it could be tenanted only by lower animals, fitted for the
circumstances under which they lived by peculiar organizations. From
this state it is admitted gradually to have been brought into that in
which we now see it; and the circumstances of the existing dispensation,
whatever may be the date of its endurance, seem to me to point not less
clearly to an end than to an origin; to a creation, when "the earth was
without form and void," and to a close, when it must either be renovated
or destroyed.
Sec. 5. In one sense, and in one only, the idea of a continuous order of
things is admissible, in so far as the phenomena which introduced, and
those which are to terminate, the existing dispensation, may have been,
and may in future be, nothing more than a gigantic development of
agencies which are in continual operation around us. The experience we
possess of volcanic agency is not yet large enough to enable us to set
limits to its force; and as we see the rarity of subterraneous action
generally proportioned to its violence, there may be appointed, in the
natural order of things, convulsions to take place after certain epochs,
on a scale which the human race has not yet lived long enough to
witness. The soft silver cloud which writhes innocently on the crest of
Vesuvius, rests there without intermission; but the fury which lays
cities in sepulchres of lava bursts forth only after intervals of
centuries; and the still fiercer indignation of the greater volcanoes,
which make half the globe vibrate with earthquake, and shrivels up whole
kingdoms with flame, is recorded only in dim distances of history: so
that it is not irrational to admit that there may yet be powers dormant,
not destroyed, beneath the apparently calm surface of the earth, whose
date of rest is the endurance of the human race, and whose date of
action must be that of its doom. But whether such colossal agencies are
indeed in the existing order of things or not, still the effective
truth, for us, is one and the same. The earth, as a tormented and
trembling ball, may have rolled in space for myriads of ages before
humanity was formed from its dust; and as a devastated ruin it may
continue to roll, when all that dust shall again have been mingled with
ashes that never were warmed by life, or polluted by sin. But for us the
intelligible and substantial fact is that the earth has been brought, by
forces we know not of, into a form fitted for our habitation: on that
form a gradual, but destructive, change is continually taking place, and
the course of that change points clearly to a period when it will no
more be fitted for the dwelling-place of men.
Sec. 6. It is, therefore, not so much what these forms of the earth
actually are, as what they are continually becoming, that we have to
observe; nor is it possible thus to observe them without an instinctive
reference to the first state out of which they have been brought. The
existing torrent has dug its bed a thousand feet deep. But in what form
was the mountain originally raised which gave that torrent its track and
power? The existing precipice is wrought into towers and bastions by the
perpetual fall of its fragments. In what form did it stand before a
single fragment fell?
Yet to such questions, continually suggesting themselves, it is never
possible to give a complete answer. For a certain distance, the past
work of existing forces can be traced; but there gradually the mist
gathers, and the footsteps of more gigantic agencies are traceable in
the darkness; and still, as we endeavor to penetrate farther and farther
into departed time, the thunder of the Almighty power sounds louder and
louder; and the clouds gather broader and more fearfully, until at last
the Sinai of the world is seen altogether upon a smoke, and the fence of
its foot is reached, which none can break through.
Sec. 7. If, therefore, we venture to advance towards the spot where the
cloud first comes down, it is rather with the purpose of fully pointing
out that there is a cloud, than of entering into it. It is well to have
been fully convinced of the existence of the mystery, in an age far too
apt to suppose that everything which is visible is explicable, and
everything that is present, eternal. But besides ascertaining the
existence of this mystery, we shall perhaps be able to form some new
conjectures respecting the facts of mountain aspects in the past ages.
Not respecting the processes or powers to which the hills owe their
origin, but respecting the aspect they first assumed.
Sec. 8. For it is evident that, through all their ruin, some traces must
still exist of the original contours. The directions in which the mass
gives way must have been dictated by the disposition of its ancient
sides; and the currents of the streams that wear its flanks must still,
in great part, follow the course of the primal valleys. So that, in the
actual form of any mountain peak, there must usually be traceable the
shadow or skeleton of its former self; like the obscure indications of
the first frame of a war-worn tower, preserved, in some places, under
the heap of its ruins, in others to be restored in imagination from the
thin remnants of its tottering shell; while here and there, in some
sheltered spot, a few unfallen stones retain their Gothic sculpture, and
a few touches of the chisel, or stains of color, inform us of the whole
mind and perfect skill of the old designer. With this great difference,
nevertheless, that in the human architecture the builder did not
calculate upon ruin, nor appoint the course of impendent desolation; but
that in the hand of the great Architect of the mountains, time and decay
are as much the instruments of His purpose as the forces by which He
first led forth the troops of hills in leaping flocks:--the lightning
and the torrent, and the wasting and weariness of innumerable ages, all
bear their part in the working out of one consistent plan; and the
Builder of the temple for ever stands beside His work, appointing the
stone that is to fall, and the pillar that is to be abased, and guiding
all the seeming wildness of chance and change, into ordained splendors
and foreseen harmonies.
Sec. 9. Mountain masses, then, considered with respect to their first
raising and first sculpture, may be conveniently divided into two great
groups; namely, those made up of beds or layers, commonly called
stratified; and those made of more or less united substance, called
unstratified. The former are nearly always composed of coherent rocks,
the latter of crystallines; and the former almost always occupy the
outside, the latter the centre of mountain chains. It signifies,
therefore, very little whether we distinguish the groups by calling one
stratified and the other unstratified, or one "coherent" and the other
"crystalline," or one "lateral" and the other "central." But as this
last distinction in position seems to have more influence on their forms
than either of the others, it is, perhaps, best, when we are examining
them in connection with art, that this should be thoroughly kept in
mind; and therefore we will consider the first group under the title of
"lateral ranges," and the second under that of "central peaks."
[Illustration: FIG. 8.]
Sec. 10. The LATERAL RANGES, which we are first to examine, are, for the
most part, broad tabular masses of sandstone, limestone, or whatever
their material may be,--tilted slightly up over large spaces (several or
many miles square), and forming precipices with their exposed edges, as
a book resting obliquely on another book forms miniature precipices with
its back and sides. The book is a tolerably accurate representation of
the mountain in substance, as well as in external aspect; nearly all
these tabular masses of rock being composed of a multitude of thinner
beds or layers, as the thickness of the book is made up of its leaves;
while every one of the mountain leaves is usually written over, though
in dim characters, like those of a faded manuscript, with history of
departed ages.
"How were these mountain volumes raised, and how are they supported?"
are the natural questions following such a statement.
And the only answer is: "Behold the cloud."
No eye has ever seen one of these raised on a large scale; no
investigation has brought completely to light the conditions under which
the materials which support them were prepared. This only is the simple
fact, that they _are_ raised into such sloping positions; generally
several resting one upon another, like a row of books fallen down (Fig.
8); the last book being usually propped by a piece of formless compact
crystalline rock, represented by the piece of crumpled paper at _a_.
[Illustration: FIG. 9.]
Sec. 11. It is another simple fact that this arrangement is not effected in
an orderly and serene manner; but that the books, if they were ever
neatly bound, have been fearfully torn to pieces and dog's-eared in the
course of their elevation; sometimes torn leaf from leaf, but more
commonly rent across, as if the paper had been wet and soft: or, to
leave the book similitude, which is becoming inconvenient, the beds seem
to have been in the consistence of a paste, more or less dry; in some
places brittle, and breaking, like a cake, fairly across; in others
moist and tough, and tearing like dough, or bending like hot iron; and,
in others, crushed and shivering into dust, like unannealed glass. And
in these various states they are either bent or broken, or shivered, as
the case may be, into fragments of various shapes, which are usually
tossed one on top of another, as above described; but, of course, under
such circumstances, presenting, not the uniform edges of the books, but
jagged edges, as in Fig. 9.
[Illustration: FIG. 10.]
Sec. 12. Do not let it be said that I am passing my prescribed limits, and
that I have tried to enter the clouds, and am describing operations
which have never been witnessed. I describe facts or semblances, not
operations. I say "_seem_ to have been," not "have been." I say "_are_
bent;" I do not say "_have been_ bent." Most travellers must remember
the entrance to the valley of Cluse, from the plain of Bonneville, on
the road from Geneva to Chamouni. They remember that immediately after
entering it they find a great precipice on their left, not less than two
thousand feet in perpendicular height. That precipice is formed by beds
of limestone bent like a rainbow, as in Fig. 10. Their edges constitute
the cliff; the flat arch which they form with their backs is covered
with pine forests and meadows, extending for three or four leagues in
the direction of Sixt. Whether the whole mountain was called out of
nothing into the form it possesses, or created first in the form of a
level mass, and then actually bent and broken by external force, is
quite irrelevant to our present purpose; but it is impossible to
describe its form without appearing to imply the latter alternative; and
all the distinct evidence which can be obtained upon the subject points
to such a conclusion, although there are certain features in such
mountains which, up to the present time, have rendered all positive
conclusion impossible, not because they contradict the theories in
question, but because they are utterly inexplicable on any theory
whatever.
Sec. 13. We return then to our Fig. 9, representing beds which _appear_ to
have been broken short off at the edges. "If they ever were actually
broken," the reader asks, "what could have become of the bits?"
Sometimes they seem to have been lost, carried away no one knows where.
Sometimes they are really found in scattered fragments or dust in the
neighborhood. Sometimes the mountain is simply broken in two, and the
pieces correspond to each other, only leaving a valley between; but more
frequently one half slips down, or the other is pushed up. In such
cases, the coincidence of part with part is sometimes so exact, that
half of a broken pebble has been found on one side, and the other half
five or six hundred feet below, on the other.
Sec. 14. The beds, however, which are to form mountains of any eminence are
seldom divided in this gentle way. If brittle, one would think they had
been broken as a captain's biscuit breaks, leaving sharp and ragged
edges; and if tough, they appear to have been torn asunder very much
like a piece of new cheese.
The beds which present the most definite appearances of abrupt fracture,
are those of that grey or black limestone above described (Chap. x. Sec.
4), formed into a number of thin layers or leaves, commonly separated by
filmy spreadings of calcareous sand, hard when dry, but easily softened
by moisture; the whole, considered as a mass, easily friable, though
particular beds may be very thick and hard. Imagine a layer of such
substance, three or four thousand feet thick, broken with a sharp crash
through the middle, and one piece of it thrown up as in Fig. 11. It is
evident that the first result of such a shock would be a complete
shattering of the consistence of the broken edges, and that these would
fall, some on the instant, and others tottering and crumbling away from
time to time, until the cliff had got in some degree settled into a
tenable form. The fallen fragments would lie in a confused heap at the
bottom, hiding perhaps one half of its height, as in Fig. 12; the top of
it, wrought into somewhat less ragged shape, would thenceforth submit
itself only to the gradual influences of time and storm.
[Illustration: FIG. 11.]
[Illustration: FIG. 12.]
I do not say that this operation has actually taken place. I merely say
that such cliffs do in multitudes _exist_ in the form shown at Fig. 12,
or, more properly speaking, in that form modified by agencies in
visible operation, whose work can be traced upon them, touch by touch.
But the condition at Fig. 12 is the first rough blocking out of their
form, the primal state in which they demonstrably were, some thousands
of years ago, but beyond which no human reason can trace them without
danger of error. The cloud fastens upon them there.
Sec. 15. It is rare, however, that such a cliff as that represented in Fig.
12 can maintain itself long in such a contour. Usually it moulders
gradually away into a steep mound or bank; and the larger number of bold
cliffs are composed of far more solid rock, which in its general make is
quite unshattered and flawless; apparently unaffected, as far as its
coherence is concerned, by any shock it may have suffered in being
raised to its position, or hewn into its form. Beds occur in the Alps
composed of solid coherent limestone (such as that familiar to the
English traveller in the cliffs of Matlock and Bristol), 3000 or 4000
feet thick, and broken short off throughout a great part of this
thickness, forming nearly[50] sheer precipices not less than 1500 or
2000 feet in height, after all deduction has been made for slopes of
debris at the bottom, and for rounded diminution at the top.
Sec. 16. The geologist plunges into vague suppositions and fantastic
theories in order to account for these cliffs; but, after all that can
be dreamed or discovered, they remain in great part inexplicable. If
they were interiorly shattered, it would be easy to understand that, in
their hardened condition, they had been broken violently asunder; but it
is not easy to conceive a firm cliff of limestone broken through a
thickness of 2000 feet without showing a crack in any other part of it.
If they were divided in a soft state, like that of paste, it is still
less easy to understand how any such soft material could maintain
itself, till it dried, in the form of a cliff so enormous and so
ponderous: it must have flowed down from the top, or squeezed itself out
in bulging protuberance at the base. But it has done neither; and we are
left to choose between the suppositions that the mountain was created in
a form approximating to that which it now wears, or that the shock which
produced it was so violent and irresistible, as to do its work neatly
in an instant, and cause no flaws to the rock except in the actual line
of fracture. The force must have been analogous either to the light and
sharp blow of the hammer with which one breaks a stone into two pieces
as it lies in the hand, or the parting caused by settlement under great
weight, like the cracks through the brickwork of a modern ill-built
house. And yet the very beds which seem at the time they were broken to
have possessed this firmness of consistency, are also bent throughout
their whole body into waves, apparently following the action of the
force that fractured them, like waves of sea under the wind. Truly the
cloud lies darkly upon us here!
[Illustration: FIG. 13.]
Sec. 17. And it renders these precipices more remarkable that there is in
them no principle of compensation against destructive influences. They
are not cloven back continually into new cliffs, as our chalk shores are
by the sea; otherwise, one might attribute their first existence to the
force of streams. But, on the contrary, the action of years upon them is
now always one of deterioration. The increasing heap of fallen fragments
conceals more and more of their base, and the wearing of the rain lowers
the height and softens the sternness of their brows, so that a great
part of their terror has evidently been subdued by time; and the farther
we endeavor to penetrate their history, the more mysterious are the
forms we are required to explain.
The three great representative forms of stratified mountains.
Sec. 18. Hitherto, however, for the sake of clearness, we have spoken of
hills as if they were composed of a single mass or volume of rock. It is
very seldom that they are so. Two or three layers are usually raised at
once, with certain general results on mountain form, which it is next
necessary to examine.
1. Wall above slope.
1st. Suppose a series of beds raised in the condition _a_, Fig. 13, the
lowest soft, the uppermost compact; it is evident that the lower beds
would rapidly crumble away, and the compact mass above break for want of
support, until the rocks beneath had reached a slope at which they could
securely sustain themselves, as well as the weight of wall above, thus
bringing the hill into the outline _b_.
[Illustration: FIG. 14.]
2. Slope above wall.
2d. If, on the other hand, the hill were originally raised as at _c_,
the softest beds being at the top, these would crumble into their smooth
slope without affecting the outline of the mass below, and the hill
would assume the form _d_, large masses of debris being in either of
these two cases accumulated at the foot of the slope, or of the cliff.
These first ruins might, by subsequent changes, be variously engulfed,
carried away, or covered over, so as to leave nothing visible, or at
least nothing notable, but the great cliff with its slope above or below
it. Without insisting on the evidences or probabilities of such
construction, it is sufficient to state that mountains of the two types,
_b_ and _d_, are exceedingly common in all parts of the world; and
though of course confused with others, and themselves always more or
less imperfectly developed, yet they are, on the whole, singularly
definite as classes of hills, examples of which can hardly but remain
clearly impressed on the mind of every traveller. Of the first, _b_,
Salisbury Crags, near Edinburgh, is a nearly perfect instance, though on
a diminutive scale. The cliffs of Lauterbrunnen, in the Oberland, are
almost without exception formed on the type _d_.
3. Slope and wall alternately.
3d. When the elevated mass, instead of consisting merely of two great
divisions, includes alternately hard and soft beds, as at _a_, Fig. 14,
the vertical cliffs and inclined banks alternate with each other, and
the mountain rises on a series of steps, with receding slopes of turf or
debris on the ledge of each, as at _b_. At the head of the valley of
Sixt, in Savoy, huge masses of mountain connected with the Buet are thus
constructed: their slopes are quite smooth, and composed of good pasture
land, and the cliffs in many places literally vertical. In the summer
the peasants make hay on the inclined pastures; and the hay is "carried"
by merely binding the haycocks tight and rolling them down the slope and
over the cliff, when I have heard them fall to the bank below, a height
of from five to eight hundred feet, with a sound like the distant report
of a heavy piece of artillery.
[Illustration: FIG. 15.]
Sec. 19. The next point of importance in these beds is the curvature, to
which, as well as to fracture, they seem to have been subjected. This
curvature is not to be confounded with that rippling or undulating
character of every portion of the slaty crystalline rocks above
described. I am now speaking of all kinds of rocks indifferently;--not
of their appearance in small pieces, but of their great contours in
masses, thousands of feet thick. And it is almost universally true of
these masses that they do not merely lie in flat superposition one over
another, as the books in Fig. 8; but they lie in _waves_, more or less
vast and sweeping according to the scale of the country, as in Fig. 15,
where the distance from one side of the figure to the other is supposed
to be four or five leagues.
Sec. 20. Now, observe, if the precipices which we have just been describing
had been broken when their substance was in a hard state, there appears
no reason why any connexion should be apparent between the energy of
_undulation_ and these _broken_ rocks. If the continuous waves were
caused by convulsive movements of the earth's surface while its
substance was pliable, and were left in repose for so long a period as
to become perfectly hard before they were broken into cliffs, there
seems no reason why the second series of shocks should so closely have
confined itself to the locality which had suffered the first, that the
most abrupt precipices should always be associated with the wildest
waves. We might have expected that sometimes we should have had noble
cliffs raised where the waves had been slight; and sometimes low and
slight fractures where the waves had been violent. But this is not so.
The contortions and fractures bear always such relation to each other as
appears positively to imply contemporaneous formation. Through all the
lowland districts of the world the average contour of the waves of rock
is somewhat as represented in Fig. 16 _a_, and the little cliffs or
hills formed at the edges of the beds (whether by fracture, or, as
oftener happens in such countries, by gradual washing away under the
surge of ancient seas) are no higher, in proportion to the extent of
surface, than the little steps seen in the centre of the figure. Such is
the nature, and such the scale, of the ranges of hills which form our
own downs and wolds, and the French coteaux beside their winding rivers.
But as we approach the hill countries, the undulation becomes more
marked, and the crags more bold; so that almost any portion of such
mountain ranges as the Jura or the Vosges will present itself under
conditions such as those at _b_, the precipices at the edges being
bolder in exact proportion to the violence of wave. And, finally, in the
central and noblest chains the undulation becomes literally contortion;
the beds occur in such positions as those at _c_, and the precipices are
bold and terrific in exact proportion to this exaggerated and tremendous
contortion.
[Illustration: FIG. 16.]
Sec. 21. These facts appear to be just as contrary to the supposition of
the mountains having been formed while the rocks were hard, as the
considerations adduced in Sec. 15 are to that of their being formed while
they were soft. And I believe the more the reader revolves the subject
in his thoughts, and the more opportunities he has of examining the
existing facts, the less explicable those facts will become to him, and
the more reverent will be his acknowledgment of the presence of the
cloud.
For, as he examines more clearly the structure of the great mountain
ranges, he will find that though invariably the boldest forms are
associated with the most violent contortions, they sometimes _follow_
the contortions, and sometimes appear entirely independent of them. For
instance, in crossing the pass of the Tete Noire, if the traveller
defers his journey till near the afternoon, so that from the top of the
pass he may see the great limestone mountain in the Valais, called the
Dent de Morcles, under the full evening light, he will observe that its
peaks are hewn out of a group of contorted beds, as shown in Fig. 4,
Plate 29. The wild and irregular zigzag of the beds, which traverse the
face of the cliff with the irregularity of a flash of lightning, has
apparently not the slightest influence on the outline of the peak. It
has been carved out of the mass, with no reference whatever to the
interior structure. In like manner, as we shall see hereafter, the most
wonderful peak in the whole range of the Alps seems to have been cut out
of a series of nearly horizontal beds, as a square pillar of hay is cut
out of a half-consumed haystack. And yet, on the other hand, we meet
perpetually with instances in which the curves of the beds have in great
part directed the shape of the whole mass of mountain. The gorge which
leads from the village of Ardon, in the Valais, up to the root of the
Diablerets, runs between two ranges of limestone hills, of which the
rude contour is given in Fig. 17, page 154. The great slope seen on the
left, rising about seven thousand feet above the ravine, is nothing but
the back of one sheet of limestone, whose broken edge forms the first
cliff at the top, a height of about six hundred feet, the second cliff
being the edge of another bed emergent beneath it, and the slope beyond,
the surface of a third. These beds of limestone all descend at a uniform
inclination into the gorge, where they are snapped short off, the
torrent cutting its way along the cleft, while the beds rise on the
other side in a huge contorted wave, forming the ridge of mountains on
the right,--a chain about seven miles in length, and from five thousand
to six thousand feet in height. The actual order of the beds is seen in
Fig. 18, and it is one of the boldest and clearest examples of the form
of mountains being correspondent to the curves of beds which I have ever
seen; it also exhibits a condition of the summits which is of constant
occurrence in stratified hills, and peculiarly important as giving rise
to the serrated structure, rendered classical by the Spaniards in their
universal term for mountain ridges, Sierra, and obtaining for one of the
most important members of the Comasque chain of Alps its well known
Italian name--Il Resegone. Such mountains are not merely successions of
irregular peaks, more or less resembling the edge of a much-hacked
sword; they are orderly successions of teeth set in one direction,
closely resembling those of a somewhat overworn saw, and nearly always
produced by successive beds emerging one from beneath the other.
[Illustration: FIG. 18.]
[Illustration: FIG. 17.]
Sec. 22. In all such cases there is an infinitely greater difficulty in
accounting for the forms than in explaining the fracture of a single
bed. How, and when, and where, were the other portions carried away? Was
each bed once continuous over a much larger space from the point where
its edge is now broken off, or have such beds slipped back into some
gulf behind them? It is very easy for geologists to speak generally of
elevation and convulsion, but very difficult to explain what sort of
convulsion it could be which passed forward from the edge of one bed to
the edge of another, and broke the required portion off each without
disturbing the rest. Try the experiment in the simplest way: put half a
dozen of hard captain's biscuits in a sloping position on a table, and
then try, as they lie, to break the edge of each, one by one, without
disturbing the rest. At least, you will have to raise the edge before
you can break it; to put your hand underneath, between it and the next
biscuit, before you can get any purchase on it. What force was it that
put its fingers between one bed of limestone 600 feet thick and the next
beneath? If you try to break the biscuits by a blow from above, observe
the necessary force of your blow, and then conceive, if you can, the
sort of hammer that was required to break the 600 feet of rock through
in the same way. But, also, you will, ten to one, break two biscuits at
the same time. Now, in these serrated formations, two biscuits are
_never_ broken at the same time. There is no appearance of the slightest
jar having taken place affecting the bed beneath. If there be, a huge
cliff or gorge is formed at that spot, not a sierra. Thus, in Fig. 18,
the beds are affected throughout their united body by the shock which
formed the ravine at _a_; but they are broken, one by one, into the
cliffs at _b_ and _c_. Sometimes one is tempted to think that they must
have been slipped back, one from off the other; but there is never any
appearance of friction having taken place on their exposed surfaces; in
the plurality of instances their continuance or rise from their roots in
waves (see Fig. 16 above) renders the thing utterly impossible; and in
the few instances which have been known of such action actually taking
place (which have always been on a small scale), the sliding bed has
been torn into a thousand fragments almost as soon as it began to
move.[51]
Sec. 23. And, finally, supposing a force found capable of breaking these
beds in the manner required, what force was it that carried the
fragments away? How were the gigantic fields of shattered marble
conveyed from the ledges which were to remain exposed? No signs of
violence are found on these ledges; what marks there are, the rain and
natural decay have softly traced through a long series of years. Those
very time-marks may have indeed effaced mere superficial appearances of
convulsion; but could they have effaced all evidence of the action of
such floods as would have been necessary to carry bodily away the whole
ruin of a block of marble leagues in length and breadth, and a quarter
of a mile thick? Ponder over the intense marvellousness of this. The bed
at _c_ (Fig. 18) must first be broken through the midst of it into a
sharp precipice, without at all disturbing it elsewhere; and then all of
it beyond _c_ is to be broken up, and carried perfectly away, without
disturbing or wearing down the face of the cliff at _c_.
And yet no trace of the means by which all this was effected is left.
The rock stands forth in its white and rugged mystery, as if its peak
had been born out of the blue sky. The strength that raised it, and the
sea that wrought upon it, have passed away, and left no sign; and we
have no words wherein to describe their departure, no thoughts to form
about their action, than those of the perpetual and unsatisfied
interrogation,--
"What ailed thee, O thou sea, that thou fleddest?
And ye mountains, that ye skipped like lambs?"
FOOTNOTES
[49] How far, is another question. The sand which the stream brings
from the bottom of one eddy in its course, it throws down in the
next; all that is _proved_ by the above trial is, that so many tons
of material are annually carried down by it a certain number of
feet.
[50] _Nearly_; that is to say, not quite vertical. Of the degree of
steepness, we shall have more to say hereafter.
[51] The Rossberg fall, compared to the convulsions which seem to
have taken place in the higher Alps, is like the slip of a paving
stone compared to the fall of a tower.