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COLLECTION

BRITISH AUTHORS

TAUCHNITZ EDITION.

VOL. 3211.

THE SCENERY OF SWITZERLAND.

The Right Hon. SIR JOHN LUBBOCK, Bart., M.P.

IN TWO VOLUMES.— VOL. I.

bibuotheek *--

geologisch-mineralogisch instituS^

Garenmarlct 1b - Leiden

TAUCHN1TZ EDITION.

By the same Author,

THE PLEASURES OF LIFE

THE BEAUTIES OF NATURE (WITH illustrations) .
THE USE OF LIFE

x vol.
x vol.
1 vol.

2 / -C-y- Gi

THE SCENERY

1 ZL

SWITZERLAN D

AND THE

CAUSES TO WHICH IT IS DUE

THE RIGHT HON.

SIR JOHN LUBBOCK, BART., M.P.

F.R.S., D.C.L., LL.D,

IN TWO VOLUMES. -VOL. I.

WITH ILLUSTRATIONS.

LEIPZIG

BERNHARD TAUCHNITZ

1897.

PREFACE.

In the summer of 1 86 1 I had the pleasure of
spending a short holiday in Switzerland with Huxley
and Tyndall. Tyndall and I ascended the Galen-
stock, and started with Benen, who afterwards lost
his life on the Haut de Cry, up the Jungfrau, but
were stopped by an accident to one of our porters,
who fell into a deep crevasse, from which we had
some difficulty in extricating him, as Tyndall has
graphically described in his Hours of Exercise on the
Alps.

From that day to this many of my holidays
have been spent in the Alps. On them I have en-
joyed many and many delightful days; to them I

PREFACE.

owe much health and happiness, nor must I omit to
express my gratitude to the Swiss people for their
kindness and courtesy.

My attention was from the first directed to the
interesting problems presented by the physical
geography of the country. I longed to know what
forces had raised the mountains, had hollowed out
the lakes, and directed the rivers. During all my
holidays these questions have occupied my thoughts,
and I have read much of what has been written
about them. Our knowledge is indeed very in-
complete, many problems still baffle the greatest
Geographers, as to others there is still much dif-
ference of opinion. Nevertheless an immense fund
of information has been gathered together; on many
points there is a fair concensus of opinion amongst
those best qualified to judge, and even where great
authorities differ a short statement of their views, in
a form which might be useful to those travelling in
Switzerland, could hardly fail to be interesting and
instructive. No such book is, however, in existence.
I urged Tyndall and several others far better

PREFACE.

qualified than I am myself, to give us such a volume,
feeling sure that it would be welcome to our country-
men, and add both to the pleasure and to the in-
terest of their Swiss trips. They were all, however,
otherwise occupied, but they encouraged me to at-
tempt it, promising me their valuable assistance, and
this must be my excuse for undertaking the task,
perhaps prematurely. Tyndall we have unfortunately
lost, but Professor Heim and Sir John Evans have
been kind enough to take the trouble of looking
through the proofs, and I am indebted to them for
many valuable suggestions.

The Swiss Government have published a series
of excellent maps, which has been prepared at the
cost of the State, under the general direction of
General Dufour. There is also a geological map by
Heim and an older one by Studer and Eschet,
which was admirable at the time it appeared, and
has in the main stood the test of more recent le-
searches. Studer was in fact the father of Swiss
Geology; he accumulated an immense number of ob-
servations which have been most useful to subsequent

PREFACE.

authors, and if I have not quoted his researches
more often, it is because I have been anxious to
give the latest authorities. In 1858 he suggested
that the Dufour map should be taken as the basis
of a geological survey on a larger scale. To this the
Swiss Government assented; they voted the modest
sum of £ 120, since increased to £400 a year, and
appointed a Commission, consisting of Messrs. B.
Studer, P. Mirian, A. Escher von der Linth, A. Favre,
and E. Desor. Under their supervision the present
geological map, in twenty-five sheets, has gradually
appeared: the last being published in 1888, on the
very day of Studer’s death.

In addition to the geological maps themselves,
the Commission have published a splendid series of
descriptive volumes, over thirty in number, by A.
Muller, Jaccard, Greppin, Moesch, Kaufmann, Escher,
Theobald, Gillieron, Baltzer, Fritsch, Du Pasquier,
Burckhardt, Quereau, Heim, Schmidt, Favre, Renevier,
Gerlach, Schardt, Fellenberg, Rolle, Taramelli, and
others.

This is not the place to catalogue the separate

PREFACE.

Volumes and Memoirs on Swiss Geology and
Physical Geography. Jaccard in his work on the
Jura and Central Switzerland enumerates no less
than 959, but among the most important I may men-
tion Heim’s magnificent work, Mechanismus der Ge-
birgsbildung, Studer’s Geologie der Schweiz, Agassiz’s
Etudes snr les Glaciers, Suess’s Das An flit z der Erde,
Favre’s Recherches Geologiques ; for the fossils that of
Heer; and among shorter publications, in addition to
those by the geologists already referred to, particularly
those of Bonney, Morlot, Penck, Ramsay, Rtitimeyer,
and Tyndall.

I have dwelt specially on the valleys of the Arve,
Rhone and Rhine, the Reuss, Aar, Limmat and
Ticino as types of longitudinal and transverse valleys;
and because they are among the districts most
frequently visited. They have, moreover, been ad-
mirably described, especially by Favre, Heim, Rene-
vier and Rtitimeyer.

I am fully conscious of the imperfections of this
book: no doubt by waiting longer it might have been

PREFACE.

made better; but I should have felt the same then
also, and in the words of Favre, “il n’y a que ceux
qui ne font rien qui ne se trompent pas. *

* Rech. Geol. lit. 7&-

CONTENTS

OF VOLUME 1.

CHAPTER 1.

THE GEOLOGY OF SWITZERLAND. Page

The influence of geology on scenery. — Difficulty of sub-
ject. — Geological history of Switzerland. — Igneous
rocks. — Gneiss. — Origin of Gneiss.— Granite. — Por-
phyry. — Protogine. — Serpentine. — Crystalline Schists.

— Carboniferous period. — Ancient mountain chain. —
Permian period. — Triassic. — Jurassic; Lias, Dogger,

Malm. — Cretaceous. — Tertiary; Eocene, Flysch, Num-
mulitic beds; Miocene. — Summary 25

CHAPTER II.

THE ORIGIN OF MOUNTAINS.

Continents the true mountain ranges. — Two classes of
mountain ranges : table mountains and folded moun-
tains. — Peaks, two classes of: volcanoes, mountains
of denudation. — Origin of mountain ranges, cooling
and consequent contraction of the earth. — Crust con-
sequently either broken up or folded. — Hence table
mountains and folded mountains. — Table mountains.

CONTENTS OF VOLUME I.

Page

— Cape of Good Hope. — Horsts.— Alps due not to
upheaval, but to folds. — Amount of compression. —

The Jura. — Amount of denudation. — Dip and strike.

— Faults. — Anticlinals and synclinals. — Folding of solid
lock, proof of. — Fractured fossils. — Cleavage ... 49

CHAPTER III.

THE MOUNTAINS OF SWITZERLAND.

General direction of pressure. — The range due to folding,
the separate summits being parts which have suffered
least from denudation. — The Rhonc-Rhine Valley. —
Geotectonic valleys, and valleys of erosion. — Trans-
verse ranges. — Enormous amount of denudation. —

The Secondary strata formerly extended over the sum-
mits. — 12,000 feet of strata probably removed from
Mont Blanc. — General section of Switzerland. — Folds,
inversion, and overthrusts. — Earthquakes. — The Plain
of Lombardy an area of sinking 81

CHAPTER IV.

SNOW AND ICE.

Snow-fields. — The snow-line. — Firn or Neve.— Red snow.

— Depth of snow. — Beauty of snow-lields.— Avalanches.

— Glaciers. — Structure of glacier ice. — Glacier grains.

— Movement of glaciers. — Rate of movement. — Cause
of movement. — Regelation. — Crevasses. — V eined
structure. — Dirtbands. — Moulins. — Moraines. — Ice
tables. — The glacier of the Rhone. — Beauty of glaciers 1 00

CHAPTER V.

THE FORMER EXTENSION OF GLACIERS.

Evidence of the former extension of glaciers. — Moraines
and fluvio-glacial deposits. — Ancient moraines, distri-

CONTENTS OF VOLUME I.

Page

bution of. — Erratic blocks.. — Polished and striated sur-
faces. — Scratched pebbles. — Upper limit of ancient
glaciers. — Flora and fauna. — Evidence of milder inter-
glacial periods. — Limits of the ancient glaciers. — Pro-
bable temperature of the Ice age. — Table of glacial de-
posits 1 3 °

CHAPTER VI.

VALLEYS.

Valleys not all due to rivers. — Geotectonic valleys. — Val-
leys of subsidence. — Plain of Lombardy. — Valley of
the Rhine near Basle.— Classes of valleys. — Longi-
tudinal valleys. — Synclinal valleys.— Anticlinal valleys.

— Combes. — Transverse valleys. — The river system
of Switzerland. — Two main directions. — Cirques. —
Weather terraces. — Age of the Swiss valleys . . . 167

CHAPTER VII.

ACTION OF RIVERS.

Three stages in river action: deepening and widening;
widening and levelling; deposition. — River gorges. —

River cones. — Cones in the Valais. — Cone of the
Borgue. — Cones and villages. — Slope of a river. —

River terraces. — Valley of the Ticino.— The Rhine.—

Val Camadra.— Effects of Hoods.— Giants’ caldrons . 188

CHAPTER VIII.

DIRECTIONS OF RIVERS.

Lake district.— Plateau of Lannemazan.— Main directions
of Swiss rivers. — The rivers of the Swiss Lowlands.—
Rivers and mountains.— The Rhone and its tributaries.

— Changes in river courses. — The tributaries of the

CONTENTS OF VOLUME I.

Page

Rhine. — Former course of the Rhone.— The Danube.

- — Age of the Swiss rivers 212

CHAPTER IX.

LAKES.

Height and depth of Swiss lakes. — Classes of lakes. —

Lakes of embankment, of excavation, and of sub-
sidence. — Crater lakes. — Corrie lakes. — Lakes due to
rockfalls. — The great lakes.— Theories of Ramsay,
Tyndall, and Gastaldi. — Lakes in synclinal vallej's. —

Lakes due to moraines. — Lakes due to changes of
level of the land. - The Italian lakes. — Colour of the
Swiss lakes. — The Beine or Blancford 234

CHAPTER X.

THE INFLUENCE OF THE STRATA UPON SCENERY.

Character of scenery dependent on weathering, the climate,
the character and inclination of the rocks. — Siliceous
rocks. — Calcareous rocks. — Argillaceous rocks. —
Gneiss.— Granite. — Crystalline Schists. — Porphyry. —
Dolomite. — Karrenfelder. — Glaciated scenery. — Mo-
raine scenery. — Rockfalls. — Earth pyramids . . . 258

TABLE OF LINEAR MEASURE.

I inch = 25.40 millim.

1 foot = 0.305 metre.

I yard = 0.914 metre.

I mile = 1.609 kilom.

LIST OF ILLUSTRATIONS.

Fig. Page

1. Cascade of Arpenaz 56

2. Diagram in illustration of folded mountains. (After

Ball) 59

3. Hall’s experiment illustrating compression. (After

Geikie) 60

4 Diagram showing the artificial folds produced in a
series of layers of clay on indianibber. (After
Favre) 60

5. Section across the Jura from Brenets to Neuchatel.

(After Jaccard) 63

6. Section from Basle across the Alps to Senago, north-

west of Milan. (After Riitimeyer) .... 64

7. Section of the Tremettaz. (After Favre and Schardt) 65

8. Diagram showing the “strike” on the ground-plan

A and the “dip” in the section B. (After
Prestwich) 66

9. Monoclinal fold 67

10. A fault. (After Geikie) 67

n. Fold-fault. Line of fault at the upper displaced bed.

(After Heim and De Margerie) 68

1 2. An inclined fold. (After Heim and De Margerie) . 68

13. Razed folds — a, anticlinal; 1 i, synclinal 69

1 4. Diagram showing anticlinal and synclinal folds . . 69

LIST OF ILLUSTRATIONS.

oi contorted mica schist. (After

(After

Heim)

which

(After

Fig.

i 5 ■ Hand specimen
Geikie) .

1 6. Section of rothidolomite. (After Heim)

17. Piece of stretched verrucano

18. Stretched and broken belemnites, half size.

Heim)

19. A fragment of nummulitic limestone. (After

20. Section of compressed argillaceous rock in

cleavage structure has been developed.

Geikie)

21. Section of a similar rock which has not undergone

this modification. (After Geikie)

22. Carboniferous trough on the Biferten Grat (T6di).'
(After Rothpletz) ......

Pioiile through the gneiss masses between the Rhone
at Viesch and the Avcrserthal. (After Schmidt)
Section from the Spitzen across the Ruchen to the
Maderanerthal. (After Heim)

Section across the Mont Blanc range. (After Favre)

26. Section across the Alps. (After Heim)

27. Diagram showing motion of a glacier. (After Tvndalli

28. Section of icefall and glacier below it, showing origin

of veined structure. (After Tyndall)

29. Diagram showing the flow of glacier ice. (After

Tyndall)

30. Sketch map of the Mer de Glace. (After Tyndall)

31* View of the Grimsel .....

32. Scratched boulder

33 - Diagram showing moraine and fluvio-glacial strata

(Fiom Le Syst . Glaciairc des Alps)

34 - Figure representing river terraces and glacial deposits

in the valley of the Aar a short distance above
Coblenz. (From Le Syst, Glaciciire des Alps)

23 -

24.

2 5 -

Page

9 1

95
1 *4

1 16

1 17

118

131

132

'34

'35

LIST OF ILLUSTRATIONS. I 7

Fig. Page

35. Map of the country between Aarau and Lucerne . . 136

36. Diagram showing crag and tail. (After Prestwich) . 148

37- View of the Brunberghorner and the Juchlistock near

the Grimsel, showing the upper limit of glacial

action. (After Baltzer) 149

38. Section of combe. (After Noe and De Margerie) . 169

39 - Do. do. . . 169

40. Do. do. . . 170

4 1 . Section from the valley of the Orbe to Mont Tendre.

(After Jaccard) 171

42. Sketch map of the Swiss rivers 175

43. Diagram in illustration of mountain structure . . . 181

44. Diagram illustrating weather terraces in the valley of

the Bienne (Jura). (After Noe and De Margerie) 184
45 - Do. do. do. . 185

46. Diagram showing the course of a river through hard

and soft strata 185

47 - The normal slope of a river j88

48. Diagrammatic section of a valley 192

49 - River Cone. Front view 196

5 °- Do. Side view 197

SI. Map showing junction of Rhone and Borgne . . . 199

5 2 - Profiles of the principal rivers in the valley of the

Garonne. (After Noe and De Margerie) . . 200

53 - Slope of the principal rivers in the valley of the

Garonne. (After Noe and De Margerie) . . 201

54 - Section across the valley of the Ticino. (After

Bodmer) 202

55 - Diagram showing river terraces in Val Camadra.

(After Heim) 203

5 &. Diagram of a river valley. Section representing harder
calcareous rock overlying a softer bed. (After

N08 and De Margerie) 204

Scenery of Switzerland . /.

LIST OF ILLUSTRATIONS.

Fig. Page

57. Diagram to illustrate a river now running on an anti-

clinal 216

58. Sketch map of the Rhone ami its tributaries . . . 219

59. River system round Chur, as it is 220

60. River system round Chur, as it used to be . . . 221

61. Section showing river terraces in the Oberhalbstein-

rhein. (After Bodmer) 223

62. Section across the Val d’Entremont. (After Bodmer) 229

63. Section across the Val d'Entremont from Six Blanc

to Catogne. (After Bodmer) 230

64. 65, 66. Diagrams to illustrate Corrie Lakes . . . 239

67. Diagram to illustrate the action of rivers and glaciers 244

68. Diagram section along the Lake of Geneva. (After

Ramsay) 245

69. Diagram illustrating the side of a lake. (After Forel) 256

70. Diagram showing the needleforms of the granite ridge

of the Gauli. (After Baltzer) 266

LIST OF STRATA.

Recent

Post-Tertiary

i Pliocene
Tertiary -{Miocene

[Eocene

Cretaceous

Secondaiy

Jurassic

Trias

Permian

Carboniferous

Palseozoic _ . _

Devonian?

Silurian ?
Cambrian ?
Crystalline Schists
Gneiss, etc.

Principal Swiss Representatives.

Glacial and Interglacial deposits

and

Mollasse and Nagelflue
INummulitic Limestone
^ Flysch

Cenomanian (Seewenkalk)
Gault

Sclirattenkalk , Urgonian ,
Aptian
Neocomian
Valangian

Malm (Hochgebirgskalk)

Dogger

Lias

| Keuper

{ Musclielkalk. Haupt Dolomite
[Bun ter Sandstein

Verrucano

{ Puddingstones , Slates , and
Sandstone

| Various Crystalline Schists
j Eruptive Rocks

GLOSSARY.

Anchi they mm . An Eocene quadruped, intermediate between
the Tapirs and the Equida. They are regarded as ancestors of
the Horse.

Anticlinal, see p. 69.

Archaan . The Geological Record may be classified in 5
divisions — I, Archaean; 2, Palceozoic (Ancient Life); 3, Secondary
or Mesozoic (Middle Life); 4, Tertiary; and 5, Quaternary.

Argillaceous Rock. Consisting of, or containing, clay.

Basalt. A black, extremely compact igneous rock, which
breaks with a splintery or conchoidal fracture.

Batrachia. The group of animals to which Frogs, Toads,
and Newts belong.

Belemnites. Cephalopods ; allied to the Squid and Cuttlefish.

Bcrgschrund, see p. 102.

Biindnerschicfer , see p. 37.

Bunter , see p. 34.

Carboniferous , see p. 32.

Cargneulc. A rock belonging to the Triassic period.

Cleavage, see p. 78.

Crevasses, see p. 114.

GLOSSARY.

Deckenschotter , see p. 162.

Dinoiherium. A gigantic Mammal belonging to the Miocene
period.

Diorite. A rock differing from granite in containing less
Silica.

Dip, see p. 66.

Dogger, see p. 27.

Dolomite. Magnesian Limestone.

Eocene, see p. 41.

Erratics, see p. 43.

Eyed-Gneiss, see p. 28.

Eelspar. Constitutes the largest portion of Plutonic and
Volcanic rocks; anhydrous, aluminous, and magnesian Silicates.
Firn, see p. 1 o 1 .

Flysch, see p. 42.

Fold Fault, see p. 68.

Foraminifera. A group of microscopic shells.

Gabbro, see p. 28. A group of coarsely crystalline rocks.
Gault, see p. 40.

Geotectonic, see p. 167.

Glacier-Grain, see p. 108.

Gneiss, see p. 26.

Granite, see p. 29.

Hauptdo loviite, see p. 35.

Hochgebirgskalk, see p. 38.

Hornblende. A group of Silicates, so called from their
horn-like cleavage, and peculiar lustre.

Horst, see p. 54.

ICeuper, sec p. 34.

Lias, see p. 36.
loess, see vol. II. p. 41.

Magma, see p. 28.

Malm, sec p. 38.

Mastodon. A gigantic quadruped, allied to the Elephant.

GLOSSARY.

Mesozoic, see under Arch (can.

Miocene, see p. 43.

Mollasse, see p. 43.

Monoclinal Fold, see p. 66.

Moraine, see p. 121.

Muschelkalk, see p. 35 -
Nagelflue, see p. 43.

Neocomian, see p. 39.

Neve, see p. lot.

Nummulites, see p. 41.

Orthoclase. A form of Felspar. An original constituent of
many crystalline rocks, including Granite, Gneiss, Syenite, etc.
Outcrop, see p. 66.

Palceotherium. A Tapir-lilce Mammal, belonging to the
Eocene period.

Palceozoic, see under Archaean.

Permian, see p. 34.

Plagioclase. A kind of Felspar N Tschermak characterises
it as a mixture of Soda Felspar and Lime Felspar.

Plutonic. Igneous rocks which have consolidated below the
surface.

Porphyry, see p. 29.

Protogine, see p. 29.

Quartz. A form of Silica.

Regelation, seep. 112.

Schist. A rock which is split up into thin irregular plates.
Secondary, see under Archaean.

Seewen-Limestone, see p. 40.

Sericite. A talc-like variety of Mica.

Serpentine, see p. 30.

Shale. A rock which splits along laminae of deposition.
Slate. A rock which splits along lines of cleavage.
Slickensides, see p. 75 -
Strike, see p. 66.

2 4

glossary.

Syenite . A mineral composed of Felspar and Hornblende.
synclinal, see p. 69.

Trachite. A lava with a low percentage of Silica.

Trias , see p. 34.

Urgonian , see p. 40.

Valangian , see p. 39.

Verrucano, see p. 33.

CHAPTER I.

THE GEOLOGY OF SWITZERLAND.

Vidi ego, quod fuerat quondam solidissima tellus,

Esse fretum: vidi factas ex lequore terras;

Et procul a pelago concha; jacuere marinae.

Ovid, Metam. xv. 262.

Straits have I seen that cover now
What erst was solid earth; have trodden land
Where once was sea; and gathered inland far
Dry ocean shells.

Ovid’s Metam., trans. by H. King.

The Scenery of Switzerland is so greatly due to
geological causes, that it is impossible to discuss the
present configuration of the surface, without some
reference to its history in bygone times. I do not,
however, propose to deal with geology further than is
necessary for my present purpose.

The subject presents very great difficulties, not
only because the higher regions are so much covered
with snow, accessible only for a few weeks in the
year, and in many places covered by accumulations

SCENERY OF SWITZERLAND.

of debris, but especially because the rocks have been
subjected to such extremes of heat and pressure
that not only have the fossils been altered, and often
entirely destroyed, but the very rocks themselves
have been bent, folded, reversed, fractured, crushed,
ground, and so completely metamorphosed that in
many cases their whole character has been changed
beyond recognition.

Igneous Rocks.— Gneiss.

To commence with the Igneous series, which
come from the fiery heart of the earth. Gneiss,
which is in Switzerland as elsewhere the fundamental
rock, forms in great part the central ranges, reap-
pearing also here and there in other parts, as for
instance on the Rhine at Laufen, and would, it is
thought, be found everywhere if we could penetrate
deep enough.

Gneiss is composed of Quartz, Felspar, and Mica,
with a more or less foliated structure. The Felspar
is generally white, but sometimes green or pink, and
has often a waxy lustre; the Mica is white, brown,
or black. The Quartz forms a sort of paste wrap-
ping round the other ingredients.

Gneiss presents the same general characters all
over the world. It is not all of the same age, and

THE GEOLOGY OF SWITZERLAND.

if some is comparatively recent, at anyrate the
oldest rock we know is Gneiss. This gives it a
peculiar interest. The foliation of Gneiss is probably
of two kinds: the one due to pressure, crushing, and
shearing of an original igneous rock such as Granite,
the other to original segregation-structure.*

“Gneiss,” says Bonney, “may be, if not actually
part of the primitive crust of the earth, masses ex-
truded at a time when molten rock could be reached
everywhere near to the surface.” ** When the crust
of the earth first began to solidify the waters of the
present ocean must have floated in the atmosphere
as steam, so that even at the surface there would be
a pressure equal to more than 1 2,000 feet of water.
The cooling also must have been very slow. Still,
the original crust, if we use the words in their
popular sense to mean the superficial layers, was
probably more like basalt, or the lavas of our exist-
ing volcanoes. Gneiss, on the other hand, must have
cooled and solidified under considerable pressure and
at a great depth. When we stand on a bare surface
of Gneiss we must remember — and it is interesting
to recollect — that it must have been originally

* Heim, Beitr. 3 . Geol. K. d. Sc/iw., L. XXIV.; Geikie,
Text-book of Geology.

** Story of our Planet.

SCENERY OF SWITZERLAND.

covered by several thousand feet of rock, all of
which have been removed.

“Probably,” says Geikie, “the great majority of
geologists now adopt in some form the opinion, that
the oldest or so-called ‘Archaean’ Gneisses are

essentially eruptive rocks Whether they were

portions of an original molten ‘magma’ protruded
from beneath the crust or were produced by a re-
fusion of already solidified parts, of that crust or of
ancient sedimentary accumulations laid down upon it,
must be matter of speculation.” *

On the other hand, Gneiss is certainly not all of
the same age, since in some instances it traverses
other strata. There appear, moreover, to be cases
in which sedimentary strata have been metamorphosed
by heat or pressure into a rock which cannot minera-
logically be distinguished from Gneiss.

Gneiss presents many varieties. The principal
are Granite -gneiss, where the schistose arrangement
is so coarse as to be unrecognisable, save in a large
mass of the rock; Diorite-gneiss; Gabbro-gneiss, com-
posed of the materials of a Dolerite or Gabbro, but
with a coarsely schistose structure; Porphyritic-gneiss
or Eyed-gneiss, in which large eye-like kernels of
Orthoclase or Quartz are dispersed through a finer

^ Text-book of Geology.

THE GEOLOGY OE SWITZERLAND. 2 Q

matrix, and represent larger crystals or crystalline
aggregates which have been partially broken down
and dragged along by shearing movements in the
rock.

Granite.

Granite, like Gneiss, is composed of Quartz, Mica,
and Felspar, but differs from it in not being foliated.

Granite is a plutonic rock and may be of any
age; it often sends veins into the surrounding strata,
which it then forces out of position, in which case
they show evidence as they approach it of being
much altered by heat. It solidified at a considerable
depth below the surface, and its upper portions pro-
bably flowed out as lava. It presents much variation:
if it shows traces of foliation it is known as Gneiss-
granite. Hornblende-granite contains Hornblende in
addition to the other elements. Diorite differs in
containing Plagioclase instead of Orthoclase, and less
Silica; if the Felspar crystals are large and well de-
fined, it is known in popular language as Porphyry.
Syenite consists of Felspar (Orthoclase), Hornblende,
and a little Quartz. Protogine, so named because
it was formerly supposed to be the oldest of all
rocks, is a Granite, containing Sericite instead of, or
with, ordinary Mica.

3 °

SCENERY OF SWITZERLAND.

Granite, like Gneiss, must have solidified under
considerable pressure, and therefore at a great depth.
In the first place, the crystals it contains could not
have been formed unless the process of cooling had
been very slow. In addition to this, they present a
great number of minute cavities containing water,
liquefied carbonic acid, and other volatile substances.
Sorby, whose main conclusions have since been
verified by others, has endeavoured to calculate what
must have been the pressure under which Granite
solidified, by measuring the amount of contraction in
the liquids which have been there imprisoned. He
considered that the Granites which he examined
must have consolidated under pressure equivalent to
that of from 30,000 to 80,000 feet of rock. The
more superficial layers probably resembled Basalt.

Serpentine.

Serpentine is a compact or finely granular rock,
olive-green, brown, yellow, or red, and has a more
or less silky lustre. There has been much doubt as
to its origin, but it is now regarded generally as an
altered igneous rock.

Crystalline Schists.

Over the Gneiss lie immense masses of Crys-
talline Schists, s.everal thousand feet in thickness.

THE GEOLOGY OF SWITZERLAND.

No fossils have been found in them, though the pre-
sence of Graphite and seams of Limestone have been
supposed to indicate the existence of vegetable and
animal life. The more ancient were perhaps depo-
sited while the waters of the ocean were still at a
high temperature. So generally distributed are these
Schists, that in the opinion of many geologists they
everywhere underlie the other stratified formations as
a general platform or foundation. In parts of Switzer-
land, however, sedimentary strata have been so much
modified by pressure, and in many cases by heat,
that it is very difficult, and even in places impossible,
to distinguish them from the older Crystalline Schists.
“At one end,” says Geikie, “stand rocks which are
unmistakably of sedimentary origin, for their original
bedding can often be distinctly seen, and they also
contain organic remains similar to those found in
ordinary unaltered sedimentary strata. At the other
end come coarsely crystalline masses, which in many
respects resemble Granite, and the original character
of which is not obvious. An apparently unbroken
gradation can be traced between these extremes,
and the whole series has been termed Metamorphic
from the changed form in which its members are
believed now to appear.” The discovery of fossils
has indeed proved that certain Schists are Silurian,

SCENERY OF SWITZERLAND.

others Devonian, Carboniferous, and even Jurassic,
but no Swiss geologists consider that the Crystalline
Schists of the Central “Massives” of the Alps are
metamorphic Mesozoic rocks.* The Schists are
generally intensely folded and crumpled. The pre-
sence of boulders of foliated Crystalline Schist in the
Carboniferous Puddingstones, proves that the folia-
tion was original, or at least anterior to the Coal
period. **

The problems, however, presented by these rocks
are, as Geikie says, so many and difficult that com-
paratively little progress has yet been made in their
solution.

The Carboniferous Period.

The earliest fossiliferous rocks in Switzerland be-
long to the Coal or Carboniferous period. The older
Cambrian and Silurian rocks, which elsewhere present
so rich a flora and fauna, and attain a thickness of
many thousand feet, are perhaps represented in
Switzerland by some of the Crystalline Schists,
though this is not yet certainly proved.

A belt of Carboniferous strata extends from
Dauphine along the valley of the lsere and the Arve,

* Heim, Quart. Jour, Geol. Soc. 1890.

** Lory, Int. Geol. Co?ig. 1888.

THE GEOLOGY OF SWITZERLAND.

presenting fossiliferous deposits at Brevent, Hunmgen,
etc. It then passes along the lower Valais, and, if
the Verrucano belongs to this period, occupies a con-
siderable part of the district between the Upper
Rhine and the Walensee. It is clear, however, and
this indeed applies to the fossiliferous strata gener-
ally, that these beds are only remnants of much
more extensive deposits. In places they have been
removed, and in others they have been deeply buried
under more recent strata. At the same time much
of Switzerland is supposed to have been land at this
period, probably forming a large island, or islands,
while the presence in the Valais and the Mont Blanc
district of Pudding-stone containing pebbles and
boulders shows that there must have been some
high land, and rapid streams. The Coal was pro-
bably formed in deposits somewhat similar to our
peat-mosses.

The vegetation consisted principally of Ferns,
Mosses, Clubmosses (Lycopodiacse), and Equisetums.
There appear to have been some flowering plants,
but the blossoms were probably inconspicuous. In-
sects were represented by forms resembling the Cock-
roach, but there were no Bees, Flies, Butterflies, or
Moths. Batrachia make their appearance, but there
were no Mammals or Birds. The Verrucano, or, as

Scenery of Switzerland. I. 3

SCENERY OF SWITZERLAND.

it is often called, Sernifite, from the Sernfthal, is a
sandy or pebbly deposit belonging either to the close
of the Carboniferous or commencement of the Per-
lman period.

Permian.

During the Permian period also Switzerland was
partly above the sea-level, partly covered by the sea.
The land appears to have gradually sunk, commenc-
ing in the east, and in the

Triassic

period the sea appears to have covered the whole
area of Switzerland. The name “Trias” was given
to it because in many districts, though not every-
where, it falls into three principal divisions, a brown,
white, green, or reddish Sandstone, known as the
Bunter Sandstein, the Muschelkalk or Shelly Lime-
stone, and the Keuper, consisting of marls and lime-
stones.

In Switzerland, as in England, there are con-
siderable salt deposits belonging to this period. An-
other very characteristic rock of this age is Gypsum,
and the Dolomites also belong to this period. Many
mineral waters spring up from, and owe their pro-
perties to, the Triassic beds. The Keuper districts
are generally rich, Dolomites on the contrary poor,

THE GEOLOGY OF SWITZERLAND.

desolate, and often almost without vegetation, but
very beautiful from their richness of colour, and rugged
forms.

The Muschelkalk is often, as, for instance, on the
Virgloria pass, a hard black limestone, splitting into
thin slabs, which take a good polish and are used
for tables.

The earliest Mammals appeared in this period.

To the Upper Trias belongs a thick deposit of
grey, whitish, or yellow Dolomite, sometimes com-
pressed into a grey or blackish Marble, which is
known as Hauptdolomite, and, especially to the east
of the Rhine, from its great durability often forms
the highest and wildest ridges of the mountains. It
is unfossiliferous.

The account here given of the geography of
Switzerland in past times differs, as will be seen,
considerably from that indicated in the maps to
Heeds Pvitncevcil World of Switzerland . Prof. Heer
regarded the present boundaries of the different
formations as indicating their original extension. This
however is certainly not the case. The Jurassic strata,
for instance, were not deposited near any land. There
are no shore animals nor pebbles, as there must have
been if they were coast deposits.

SCENERY OF SWITZERLAND.

Jurassic.

The principal Jurassic strata in Switzerland are
the Lias, the Dogger, and the Malm. They attain
together a thickness of over 2500 feet. During this
period Ammonites and Belemnites reached their
fullest development, as also did the great Sea-reptiles,
the Icthyosaurus and Plesiosaurus. At this period
also flourished the flying reptiles or Pterodactyles,
and we also meet the first bird (Archaeopteryx),
which differed from all existing species, by the pos-
session of a long tail, and in other ways.

Lias.

During this period the whole of Switzerland ap-
pears to have been covered by the sea. There must
however have been land not very far off, as remains
of Beetles, Cockroaches, Grasshoppers, Termites,
Dragon-flies, Bugs, and other Insects occur in the
Lias of Schambelen, near the junction of the Reuss,
the Aar, and the Limmat, and elsewhere. No Bees,
Butterflies, or Moths have been met with.

It is probable that the Black Forest and the
Vosges were dry land. The fossils, however, on the
whole, indicate a deep sea. The Lias is grey or
blackish, calcareous, sandy, or argillaceous stratum.
The dark color is probably owing to the amount of

THE GEOLOGY OF SWITZERLAND.

organic matter which it contains. Heer suggests that
the best explanation may be afforded by the Sar-
gasso Sea. The Atlantic Ocean, for an area of about
40,000 square miles, is covered by Sargasso-weed so
densely that ships sometimes find a difficulty in
forcing their way through it. The sea is deep, and
the fragments of dead weed are probably quite de-
cayed before they reach the bottom, to which they
would give a dark colour. He thus explains the colour
of this limestone.

The “Btlndner Schiefer” so largely developed in
the Grisons and Valais are now considered, from the
fossils which have been discovered in several places,
to belong to this period. It it probable however that
the strata marked as Btlndner Schiefer on the Swiss
maps do not all belong to the same period.

Dogger or Brown Jura.

Switzerland was for the most part under water
at this period, but that there must have been land
in the neighbourhood during some part of the time
is proved by the existence, near Porrentruy, of beds
containing several species of Limpets (Patella), Peri-
winkles (Purpura), Mussels (Mytilus), Neritas, and
other shore molluscs. It is probable that the Black
Forest and the Vosges were then dry land.

SCENERY OF SWITZERLAND.

Malm, or Upper Jurassic.

The Malm is characterised by a considerable
development of Coral reefs, which often attained a
great thickness. Between the Corals, which in some
cases still retain their natural position, are many re-
mains of Sea-urchins, Sponges, Molluscs, and some
Crustacea, united by calcareous cement into a more
or less solid rock. They are often beautifully pre-
served, having been embedded in the soft mud of a
quiet sea, which extended completely over the Cen-
tral Alps. Indeed the southern shore of the Jurassic
Sea must, in Heim’s opinion, be looked for in
northern Africa.

The Malm is yellow and white in the Jura, blue-
black in the Alps; by its hard, bare, steeply inclined
rocks, and dry sterile slopes, it gives a special char-
acter to the landscape, while the Dogger, and still
more the Lias, from their numerous marly layers,
furnish a very fertile soil. Where Malm is a dark-
bluish, grey, conchoidal, calcareous rock, it is known
as “Hochgebirgskalk.” In the celebrated deposits of
Solenhofen many remains of Insects occur, includ-
ing a Moth, the earliest Lepidopterous insect yet
known.

THE GEOLOGY OF SWITZERLAND. 39

Cretaceous.

As in the Jurassic period, so also in the Cre-
taceous, Switzerland was under the sea. To the
east, however, was dry land. The complete dif-
ference between the animals of the Malm or Upper
Jurassic, and then of the Neocomian or Lower Cre-
taceous, appear to imply a change of conditions or
great lapse of time. It was at one time supposed*
that the southern shore of the Swiss Cretaceous Sea
followed a line drawn from the Walensee to Altorf,
the Lake of Brienz and Bex, but though this is the
present limit of the strata they once extended much
farther, and have been removed by denudation.
Heim considers that islands began to show them-
selves in the region of the Central Alps in Cretaceous
times.

The Swiss Cretaceous strata fall into five principal
divisions. The first or oldest — ' Valangian — consists
of a dark hard silicious and sometimes oolitic lime-
stone as on the Sentis, or of bluish grey marls and
limestone as in the Jura.

The Neocomian, from the old name of Neu-
chatel, is sometimes a dark gray or black hard marl,
sometimes a bluish grey marl which easily disinte-

Heer, Primceval World of Switzerland .

4 o

SCENERY OF SWITZERLAND.

giates in the air, but contains beds of excellent stone
of which Neuchatel is built.

The Urgonian (so called after the town of Orgon,
near Arles), or Schrattenkalk, is widely distributed in
the Alps. It is a hard white limestone, the surface
of which is often furrowed by innumerable channels,
which form a perfect labyrinth. It stands in rocky
walls often several hundred feet high, and from its
great powers of resistance often forms the ridges and
water-sheds. It is arid and barren, offering a great
contrast to the Neocomian, which generally bears a
luxuriant vegetation.

The Gault contains many dark green grains
which are a silicate of protoxide of Iron. It forms
the dark bands which are so conspicuous against the
paler colour of the other Cretaceous rocks.

The Seewen Limestone, so called from the village
of Seewen on the Lake of Lowerz, corresponds in
age to our Chalk, and like it consists mainly of
microscopic shells. The eastern and western parts
of Switzerland differ considerably in the species.
The Cretaceous deposits being of marine origin we
cannot expect to know much of the land animals or
plants. The forests, however, contained Cycads and
Conifers, Pines, Sequoias, etc., and Dicotyledonous
trees now make their appearance, the earliest being

THE GEOLOGY OF SWITZERLAND.

4 1

a species resembling a poplar found in the Cretaceous
beds of Greenland. In the upper Cretaceous strata
Dicotyledons are more numerous, and it is interest-
ing to find that they are mostly species in which the
pollen is carried from flower to flower by the wind,
or such as Magnolia, which are fertilised by beetles.
Bees and Butterflies were still apparently absent or
rare, and hence also the beautiful flowers specially
adapted to them.

Eocene.

At this period the formation of islands on the
site of the present Alps appears to have commenced.
The two principal rocks of the Eocene period are
the Nummulitic Limestone and the Flysch. They
represent differences of condition rather than of time.
Bands of Nummulitic Limestone often occur in the
Flysch, showing that for a while the sea was favour-
able for the development of Nummulites. Then the
conditions changed, and they disappeared. This
happened again and again.

Nummulitic Limestone.

The Nummulitic Limestone is so called because
it contains numerous Foraminifera, the shells of which
are in some species so flattened that they resemble

SCENERY OF SWITZERLAND.

pieces of money. In many cases, moreover, the size
increases the resemblance. The sea in which they
lived was of great extent. The pyramids are built
of Nummulitic Limestone, and the Nummulites are
traditionally said to be the petrified remains of the
lentils on which the children of Israel were fed by
Pharaoh. They occur also in Asia Minor, Persia, on
the Himalayas, and in Thibet, where they now rise
to a height of 5000 metres.

Flysch.

The Flysch is a very remarkable and important
deposit. The name is a local Bernese expression,
which was adopted by Studer. Flysch is sometimes
marly, sometimes calcareous, sometimes sandy. It is
often slaty, and is extensively worked. It attains a
thickness of nearly 2000 metres, and is evidently
marine, but except in the slates of Matt, the only
fossils found in it have been certain impressions
which have been supposed to be Seaweeds, or per-
haps Worm burrows. What are the conditions under
which these have been preserved when all other
traces of organic remains have perished, is a mys-
tery. The Flysch mountains present soft outlines,
and their slopes support a rich carpet of vegetation.

These are the two principal deposits of the

THE GEOLOGY OF SWITZERLAND.

Eocene period, so far as Switzerland is concerned.
In other strata numerous fossils have been found, in-
cluding many Mammalia, and even a Monkey.

Miocene.

During this period the main elevation of the
Alps took place. We should naturally expect that
rapid rivers would rush down from the heights bring-
ing masses of gravel with them, and in fact we find
enormous deposits of coarse gravel, often cemented
into a hard rock, and containing blocks six inches,
a foot, and even sometimes as much as a yard in
diameter. This conglomerate is known as the Nagel-
flue, and the materials of which it is composed be-
come gradually finer as we recede from the Alps,
forming a more or less marly deposit known as the
Mollasse. It attains a great thickness; indeed the
whole of the Rigi from the Lake of Lucerne to the
summit consists of Nagelflue. The Mollasse is com-
posed of several deposits, some fresh-water and some
marine; it is probable that the conditions may have
been different in different parts of what are now the
Swiss lowlands. The pleasant scenery of Central
Switzerland is greatly due to the Mollasse. The
Freshwater Mollasse is generally soft, but the Marine
beds afford excellent building materials. Large

SCENERY OF SWITZERLAND.

quantities are brought to Zurich from the upper part
of the lake. It contains beds of brown coal and is
rich in fossils. Indeed the deposits at Oeningen
contain perhaps the richest collection of fossils in the
world. Taking the Miocene period as a whole we
know nearly 1000 species of plants and 1000 in-
sects; of reptiles 32 species have been discovered,
whereas in Switzerland now there are only 27. As
regards Mammals 59 have been determined, while
at present Switzerland contains 62; but though the
numbers are so nearly the same, the species are all
different and belong to very different groups. Of the
present species 15 are bats, but no bat has been
found in the Swiss Miocene. It contains on the
other hand no less than 25 Pachyderms. The Wild
Boar is the only present representative of the order,
but during the Miocene period Tapirs and tapir-like
Palseotheria, the horse-like Anchitherium, two species
of Mastodon, the Dinotherium and no less than 5
species of Rhinoceros, roamed over the Swiss woods
and plains. Of plants we know already 1000 species.
Many resemble, and are probably ancestral forms of,
those now flourishing in very distant parts of the
world. Thus there are several Sequoias, one of which
(Sequoia Langsdorfii) closely resembles the Redwood
of California, and another (Sequoia Sternbergii) the

THE GEOLOGY OF SWITZERLAND.

gigantic Wellingtonia. Another species resembles the
Marsh Cypress of the southern United States. There
are also Australian types such as Habeas and Gre-
villeas, while Palms, Liquidambars, Cinnamon, Figs,
Camphor trees, and many other southern forms also
occur. Of Oaks Prof. Heer has described no less
than 35 species.

Moreover many of the Miocene plants have been
found in the far North, implying a comparatively
uniform and mild climate. Thus Sequoia Sternbergii
is abundant in the lignites of Iceland, and Sequoia
Nordenskioldi has been found in Greenland. As a
whole the Flora resembles that of the present day,
but represented by types now scattered over the whole
world, and has most affinity with that of North
America, as it contains over 200 North American
against 140 European types. They have as a rule
small and wind-fertilised flowers. Those which are
more conspicuous, and which add so much beauty
to our modern flora, were less numerous in Miocene
times; and many families are altogether absent, such
as Rosacea:, Crucifers, Caryophyllaceae, Labiatae,
Primulaceae, etc. Bees and Butterflies, though al-
ready existing, had not yet so profoundly modified
and developed the flowers. The Miocene species
were all killed off or driven south by the Glacial

SCENERY OF SWITZERLAND.

Period and succeeded by others better able to stand
a cold climate. There was on the contrary no such
complete change in the marine flora and fauna.

Summary.

Looking at the Alps as a whole the principal
axis follows a curved line from the Maritime Alps
towards the north-east by Mont Blanc, Monte Rosa,*
and St. Gotthard to the mountains overlooking the
Engadine.

The geological strata follow the same direction.
North of a line running through Chambery, Yverdun,
Neuchatel, Soleure, and Olten to Waldshut on the
Rhine are Jurassic strata; between that line and a
second nearly parallel and running through Annecy,
Vevey, Lucerne, Wesen, Appenzell, and Bregenz on
the Lake of Constance, are the lowlands, occupied
by later Tertiary strata; between this second line and
another passing through Albertville, St. Maurice, Leuk,
Meiringen, and Altdorf lies a more or less broken band
of older Tertiary strata, south of which are first a
Cretaceous zone, then one of Jurassic age, followed
by a band of crystalline rocks, while the central core,
so to say, of the Alps, consists mainly of Gneiss or

* This name has no reference to colour, but is derived from
“reuse,” a local name for glacier.

THE GEOLOGY OF' SWITZERLAND.

Granite. If we draw a line across Switzerland, say
from Basle to Como, we find from Basle to Olten,
say to the line of the Aar, Jurassic formations thrown
into comparatively gentle undulations, and stretching
from south-west to north-east. From Olten to Lucerne,
the great plain of Switzerland is made up of upper
Tertiary strata, known as Mollasse, and Nagelflue,
consisting of sand and gravel washed down from the
rising mountains and deposited partly in a shallow
sea, partly in lakes. Near Lucerne we come upon
Eocene strata, also of marine origin, which have been
raised to a height of as much as 2000 metres.

Continuing in the same direction, and soon after
passing Vitznau, we come upon Cretaceous rocks,
which occupy most of the canton of Nid Dem Wald.
In Ob Dem Wald we find ourselves on Jurassic. In
other parts of Switzerland a considerable thickness of
Triassic strata appears beneath the Jurassic, and rests
on Verrucano, one of the Carboniferous series, but
along our line the Jurassic region is immediately fol-
lowed by Crystalline rocks, and Gneiss, forming the
great Central ridge of Switzerland, and reaching as
far as the Lake of Como. On the south of the
mountain range, as on the north, the Gneiss is
followed in succession by Carboniferous, Triassic,
Jurassic, Cretaceous, and Tertiary strata, but they

4 8

SCENERY OF SWITZERLAND.

form narrower belts. Bellagio is on Trias; from the
Island of Comacino the Gulf of Como is surrounded
by Jurassic strata, south of which is a band of Cre-
taceous, running from the Lago Maggiore, opposite
Pallanza, by Mendrisio, Como, Bergamo, and the
south end of the Lago d’Iseo to Brescia, and so on
further to the east.

Speaking roughly then we may say that the back-
bone of Switzerland consists of Gneiss and Granite,
followed on both sides by Carboniferous, Triassic,
Jurassic, Cretaceous, and Tertiary strata. These
however are all thrown into a succession of gigantic
folds, giving rise to the utmost complexity. The
similarity of succession on the two sides of the ridge
gives reason for the belief that the Triassic, Jurassic,
and Cretaceous strata north and south of the Alps
were once continuous, and this impression is con-
firmed by other evidence, as will be shown in the
following chapters.

THE ORIGIN OP MOUNTAINS.

CHAPTER II.

THE ORIGIN OF MOUNTAINS.

There rolls the deep where grew the tree.

O earth, what changes hast thou seen!

There, where the long street roars, hath been
The stillness of the central sea.

The hills are shadows, and they flow

From form to form, and nothing stands;

They melt like mist, the solid lands,

Like clouds they shape themselves and go.

Tennyson.

The true mountain ranges, that is to say, the
elevated portions of the Earth’s surface, are the con-
tinents themselves, on which most mountain chains
are mere wrinkles; nevertheless when we speak of
mountains, we mean as a rule those parts of the
land which stand high relatively to the sea-level.

Mountain ranges in this sense may be classed
under two main heads,* viz.: —

* I say “main” heads, because in certain cases there may
be other explanations. Yon Richthofen has suggested that the
Dolomites of the Tyrol were originally coral reefs.

Scenery of Switzerland. I.

SCENERY OF SWITZERLAND.

I. Table mountains.

II. Folded mountains.

The highest points or peaks may be again
divided into two classes — volcanoes, and those due
to weathering.

Volcanoes.

Volcanoes have had comparatively little effect on
the scenery of Switzerland. There is only one group
of hills in Switzerland, those of Hohgau near the
Lake of Constance, which is of Volcanic origin.

There are indeed certain isolated masses of
igneous rock, as for instance in the Chablais, and
again near Lauchern in Wandelibach, which are pro-
bably the necks of ancient Volcanoes.

Mountains of Denudation.

Let us imagine a country raised above the water
with a gradual and uniform slope towards the sea.
Rivers would soon establish themselves, guided by
any inequalities of the surface, and running at more
or less equal intervals down to the water level. They
would form valleys, down the sides of which
secondary rivulets would flow into the main streams.
The rain and frost would denude with especial
rapidity those parts of the surface which offered the
least effective resistance, and thus not only would

THE ORIGIN OF MOUNTAINS.

the original watershed be cut into detached summits,
but secondary ridges would be formed approximately
at right angles, to be again cut into detached summits
like the first.

The general opinion of geologists used, however,
to be, in the words of Sir R. Murchison, that “most
of the numerous deep openings and depressions
which exist in all lofty mountains were primarily due
to cracks which took place during the various move-
ments which each chain has undergone at various
periods.”

In support of this view such gorges as those of
Pfaffers, the Trient, the Gorner, the Aar, etc., were
quoted as conclusive cases, but even these are now
proved to have been gradually cut down by running
water.

The rapidity of denudation is of course affected
greatly by the character of the strata, so that the
present level depends partly on the original con-
figuration, partly on the relative destructibility of the
rock. The existing summits are not those which
were originally raised the highest, but those which
have suffered the least. And hence it is that so
many of the peaks stand at about the same level.
Everyone who has ever stood at the top of such a
mountain as the Piz Languard, which I name as

4 *

SCENERY OF SWITZERLAND.

being so easily accessible and so often visited, must
have been struck by this fact; and must have noticed
that the valleys are a far less important part of the
whole district than they seem when we are below.
The Matterhorn is obviously a remnant of an ancient
ridge, which gives the peculiar straight line at the
summit. The noble mass of the Bietschorn again,
which forms such an imposing object as we look
down the valley of St. Niklaus across the Rhone at
Visp, is a part of the surrounding granite which has
resisted attack more successfully than the rest of the
rock. The mountain crests, solid as they look from
a distance, are often covered by detached fragments,
shattered by storms, and especially by frost.

Mountain Ranges.

The present temperature of the Earth’s surface
is due to the Sun, that supplied from the original
heat of the planet being practically imperceptible.
The variations of temperature due to seasons, etc.,
do not extend to a greater depth than about
io metres. Beyond that we find as we descend
into the Earth that the heat increases on an average
about 1° Fahr. for every 50 metres. * Even, there-

* Agassiz, however, in the case of the Calumet Mine near
Lake Superior, found a rate of i° Fahr. for every 223 ft. (Amer.
fourn. of Science, 1895).

THE ORIGIN OF MOUNTAINS.

fore, at comparatively moderate depths the heat must
be very great. Many geologists in consequence, have
been, and are, of opinion that the main mass of the
Earth consists of molten matter. We know, however,
that the temperature at which fusion takes place is
raised by pressure, and it must not, of course, be
assumed that the temperature continues to increase
so rapidly beyond a certain depth. Other great
authorities,* therefore, are of opinion that the mass
of the Earth, though intensely hot, is solid, with, no
doubt, lakes of molten matter. In either case the
central mass continues slowly to cool and conse-
quently to contract. The crust, however, remains at
the same temperature and consequently of the same
dimensions. This being so, under the overwhelming
force of gravity one of the two things must happen.
Either (i), parts of the crust must break off and sink
below the rest; or (2), the surface must throw itself
into folds.

Table Mountains.

Where the first alternative has happened we find
more or less numerous faults.

Those parts which have not sunk, or which have

* See, for instance, Lord Kelvin, Lectures and Addresses,
vol. II.

SCENERY OF SWITZERLAND.

sunk less than the rest, remain as tabular mountain
masses, more or less carved into secondary hills and
valleys by the action of rain and rivers. Such, for
instance, is the Table Mountain of the Cape of Good
Hope; its relative height is not due to upheaval, but
to the surrounding districts having sunk.

As the crust of the Earth cooled and solidified,
certain portions “set,” so to say, sooner than others;
these form buttresses, as it were, against which the
surrounding areas have been pressed by later move-
ments. Such areas have been named by Suess
“Horsts,” a term which it may be useful to adopt,
as we have no English equivalent. In some cases
where compressed rocks have encountered the resist-
ance of such a “Horst,” as in the northwest of Scot-
land and in Switzerland, they have been thrown into
most extraordinary folds, and even thrust over one
another for several miles.

Murchison long ago expressed his surprise at the
existence of great plains such as those of Russia
and Siberia. L. v. Buch suggested as a possible ex-
planation that they rested on solid masses which had
cooled down early in the history of the planet, and
thus had offered a successful resistance to the folds
and fractures of later ages.

THE ORIGIN OF MOUNTAINS.

55 '

Folded Mountains.

The Swiss mountains, however, belong to another
class, and have a very different character. They are
greatly folded and compressed (see Figs. 23-26).
Fig. 1 represents the Cascade of Arpenaz in the
valley of the Arve. It shows a grand arch, but does
not include the whole fold, which takes the form of
an S, the middle part only being included in the
photograph.

It used to be supposed that mountains were up-
heaved by forces acting more or less vertically from
below upwards, and the igneous rocks which occupy
the centre of mountain ranges were confidently ap-
pealed to in support of this view. It must be con-
fessed that when we first visit a mountainous region,
this theory seems rational and indeed almost self-
evident. It is now, however, generally admitted that
such an explanation is untenable; that the igneous
rocks were passive and not active; that, so far fiom
having been the moving force which elevated the
mountains, they have themselves been elevated, and
that this took place long after their formation. Near
the summit of the Windgalle, in the Reuss district,
is, for instance (Fig. 24), a mass of Porphyry. Ihe
eruption of this Porphyry must have taken place be-

Fig. i. — Cascade of Arpcnaz.

THE ORIGIN OF MOUNTAINS.

fore the Jurassic period, for rolled pebbles of it
occur in that rock. On the other hand, the fold on
the summit of the Windgiille contains Eocene strata.
The origin of the Porphyry then is earlier than the
Jurassic; the elevation of the mountain is later than
the Eocene. It is clear, therefore, that the Porphyry
had nothing whatever to do with the origin of the
Windgiille mountain.

The igneous rocks have moreover produced no
effect on the strata which now rest on them. If,
however, they had been intruded in a molten con-
dition, they must have modified the rocks for some
distance around. It is evident therefore that the
igneous rocks had cooled down before the overlying
strata were deposited. The elevation of the Alps
only commenced in the Tertiary period, but we know
that the Granite of the southern Alps is, for the most
part, pre- Carboniferous, that the Porphyry of Botzen
belongs to the Permian period, the younger Porphyry
to the Trias, and that the Gneiss of the central range
of the eastern Alps is still older; it is evident then,
that these plutonic rocks can have taken no active
part in the upheaval of the Alps, which occurred so
much later.

We may, indeed, lay it down as a general pro-
position that folded mountains are not due to volcanic

SCENERY OF SWITZERLAND.

action. When the two are associated, as in the
Andes, the volcanoes are due to the folding and
crushing, not the folding to the volcanoes.

The Alps then have not been forced up from
below, but thrown into folds by lateral pressure.
This view was first suggested by De Saussure, worked
out in fuller detail by Sir Henry De La Reche in
1846, and recently developed by Ball, Suess, and
especially by Heim.*

Moreover, as the following sections show, (Figs. 1,
5, 23-26) we have every gradation from the simple
undulations of the Jura (Fig. 5) to the complicated
folds of the Alps (Figs. 1, 23-26).

But why are the surface strata thus thrown into
folds? When an apple dries and shrivels in winter,
the surface becomes covered with ridges. Or again,
if we place some sheets of paper between two weights
on a table, and then bring the weights nearer to-
gether, the paper will be crumpled up.

In the same way let us take a section of the
Earth’s surface A B (Fig. 2) and suppose that, by
the gradual cooling and consequent contraction of
the mass, A B sinks to A 1 B 1 , then to A 2 B 2 , and

* See especially Heim’s great work, Untersuchungen it. d.
Mechanisnms d. Gebirgsbildung. I ought perhaps, however,
to add that this view is not universally accepted.

THE ORIGIN OF MOUNTAINS.

finally to A3 £3. Of course if the cooling of the
surface and of the deeper portion were the same,
then the strata between A and B would themselves
contract, and might consequently still form a regular
curve between A3 and B3. As a matter of fact,
however, the strata at the surface of our globe have
long since approached a constant temperature. Under
these circumstances there would be no contraction of
the strata between A and B corresponding to that

in the interior, and consequently they could not lie
flat between A3 and B3, but must be thrown into
folds, commencing along any line of least resistance.
Sometimes, indeed, the strata are completely inverted,
and in other cases they have been squeezed for
miles out of their original position. “The great
mountain ranges,” says Geikie, “may be looked upon
as the crests of the great waves into which the crust
of the Earth has been thrown.” Sir James Hall
illustrated the origin of folds very simply (Fig. 3 ) by

Fig. 4. — Showing the artificial folds produced in a series of layers of clay on indiarubber, according to an

experiment by Prof. A. Favre.

SCENERY OF SWITZERLAND.

placing layers of cloth under
a weight, and then compressing
the two sides, and more com-
plete experiments have since
been made by Favre, Ruskin
and Cadell.

Fig. 4 shows the result of
one of Favre’s experiments, in
which he used the contraction

of an indiarubber band to pro-
duce the folds.

The shortening of the Jura
amounts to about one-fifteenth.
The strata between Basle and
the St. Gotthard, a distance of
1 30 miles, would, if horizontal,
occupy 200 miles. Heim estim-
ates the total compression of the

THE ORIGIN OF MOUNTAINS.

Alps at a minimum of 1 20,000 metres* The original
breadth of the strata forming the Aarmassif was at
least double the present, and the same may be said
of the central range. The Appalachians are calcu-
lated to be compressed from 150 miles to 65.

It very seldom happens that such a range of
mountains consists of a single fold. There are
generally several, one being as a rule formed first,
and others outwards in succession. In both the
Alps and the Jura, the southern folds are the oldest.
In Central America, again, there are several longi-
tudinal ranges, and the volcanoes are generally
situated on cross lines of fracture, so that they are
in rows, at right angles to the general direction of
the mountains, and in almost every case the outer
crater, or that towards the Pacific, is the only one
now active.

A glance at any good map of the Jura will show
a succession of ridges running parallel to one another
in a slightly curved line from south-west to north-
east. That these ridges are due to folds of the
Earth’s surface is clear from the following figure
(Fig. 5) in Jaccard’s work on the Geology of the
Jura, showing a section from B renets due South to
Neuchatel by Le Locle. These folds are com-

* Mcchanismus d. Gebirgsbildung , v. 2.

6 2

SCENERY OF SWITZERLAND.

paratively slight and the hills of no great height. In
the Alps the strata are much more violently dis-
located and folded.

The mountains seem so high that we are apt to
exaggerate the relative elevation. The following
figure (Fig. 6) by Rutimeyer gives the outline of the
Alps from Basle to near Milan. This section is only
intended to indicate the relative height, and is sup-
posed to follow the line of one of the great valleys.
Even so, however, it ought to have shown the sudden
dip to the south of the main ridge.

The folded structure throws light on the curious
fact that there are much fewer faults in Switzerland
than in such a region as, for instance, that of our
coal fields.

In folded districts the contortions are often so
great that if we could not follow every step they
would certainly be regarded as incredible. Previous
folds are themselves in some cases refolded, and in
others the lateral pressure has not only raised the
strata into a vertical position, as for instance the
Chalk and Tertiary sands of Alum Bay in the Isle
of Wight, but has in some cases pushed the folds
for miles, and has even thrown them over, so that
the sequence is inverted, and the more ancient lie
over the more recent strata in reverse order. As

Brenets Ch: de Ponillerel Le Locle T 0

€28 sooo 9?° La j>agne

Fig. 5. — Section across the Jura from Brenets to Neuchatel.

Fig. 6. — Section from Basle across the Alps to Senago, north-west of Milan. B, Basle. .7, Jura. A, Aar, near Olten.
Ap , Alps. S, Senago. Inclination from Basle to summit of Jura, i° 37'; from Basle to the summit of the Alps, i° 43'.

SCENERY OF SWITZERLAND.

the cooling, and consequent contraction
of the Earth, is a continuous process, it
follows that mountain ranges are of very
different ages; and, as the summits are
continually crumbling down, and rain
and rivers carry away the debris, the
mountain ranges are continually losing
height. Our Welsh hills, though com-
paratively so small, are venerable from
their immense antiquity, being far older,
for instance, than the Vosges, which
themselves, however, were in existence
while the strata now forming the Alps
were still being deposited at the bottom
of the Ocean. But though the Alps are
from this point of view so recent, it is
probable that the amount which has
been removed is almost as great as that
which still remains. They will, however,
if no fresh elevation takes place, be still
further reduced, until nothing but the
mere stumps remain. What an enormous
amount of denudation has already taken
place is shown for instance in Fig. 7,
representing the mountain of Tremettaz
near the valley of the Rhone, between

THE ORIGIN OF MOUNTAINS.

Scenery of Switzerland. /.

Fig. 7. — Section of the Tremettaz.

SCENERY OF SWITZERLAND.

the Niremont and
is evident, not only

**i !4
<5

d jjj

p SI

[i-

p 'I

3 !',!

the valley of the Sarine, where it
that the strata have been cut off,
but that what is now the top of
the mountain was once the
bottom of a valley.

The edges of strata which
U appear at the surface of the
ground are termed their “Out-
crop.” Sometimes they are
horizontal, but if not; the in-
clination is termed their “Dip”
(Fig. 8, B). A horizontal line
drawn at a right angle to the
Dip is called the “Strike” (Fig.
8, A ) of the rocks. If the sur-
face of the ground is level this
will coincide with the outcrop.
In a mountainous district such
as Switzerland this is however
rarely the case.

Where strata have been
bent, as in Fig. g, it is called
a monoclinal fold. Where the
subterranean forces have rup-
tured the strata and pushed the
one side of the crack more or

!53

THE ORIGIN OF MOUNTAINS. 67

less upwards or downwards (Fig. io), it is termed a
fault.

Faults may be small, and the difference of height
between the two sides only a few inches. On the
other hand, some are immense. In the case of one

great fault described by Ramsay, the difference is no
less than 29,000 feet, and yet so complete has been
the denudation that the surface shows no evidence
of it, and one may stand with a foot on each side,
unconscious of the fact that the stratum under the

5 *

SCENERY OF SWITZERLAND.

one represents a geological horizon so much above
that under the other.

When the strata bent somewhat before the frac-
ture we have a fold-fault (Fig. 1 1).

Fig. ii. — Line of Fault at the upper displaced bod. The beds are bent
near the fault by the strain in slipping.

Where a fold is much compressed the limbs
would become thinner and thinner (Fig. 12), while
the strata in the arch and the trough would be com-
pressed and consequently widened.

Fig. 12. — An Inclined Fold.

When the arch A, instead of being upright is

THE ORIGIN OF MOUNTAINS. 69

thrust to one side, it is said to be inclined or re-
cumbent (Fig. 12).

Where strata are thrown into folds the convex
portion is termed an anticlinal (Fig. 14, A) and the
concave a synclinal (Fig. 14, B). The same terms
are applicable when the surface has been planed
down so that the strata would dip as in Fig. 13.

The inner strata of any fold are called the core,
those of an anticlinal (Fig. 14, A) being called the
arch core, those of a synclinal (Fig. 14, B) the trough
cere.

Fig. 14. — Diagram showing Anticlinal and Synclinal Folds.

It is obvious of course that when strata are
thrown into such folds, they will, if strained too
much, give way at the summit. Before doing so,
however, they are stretched and consequently
loosened, while on the other hand the strata at the
bottom of the fold are compressed; the former, there-

SCENERY OF SWITZERLAND.

fore, are rendered more susceptible of disintegration,
the latter on the contrary acquire greater powers of
resistance.

The above diagram, Fig. 14, represents six strata
(1-6) supposed to be originally of approximately
equal hardness, but which, after being thrown into
undulations, are rendered more compact in the
hollows and less 'so in the ridges. Denudation will
then act more effectively at A, C, E, than at B, D,
F, and when it has acted long enough the surface
will be shown by the stronger line. This will be
still more rapidly the case if some of the strata are
softer than others. Where they are brought up to
the surface erosion will of course act with special
effect. Hence it often happens that hills have be-
come valleys, and what were at first the valleys have
become mountain tops. As an illustration of the
former I may mention the valley of the Tinitue (Fig.
98, vol. 11. p. 87); of the latter, the Tremettaz (Fig. 7)
or the Glarnisch.

In other eases where the summit is not at the
very base of the trough, the edges of some stratum
rather harder than the rest, project as two more or
less pointed peaks, leaving a saddle-shaped depression
in the centre.

Highly inclined strata are often worn away so as

THE ORIGIN OF MOUNTAINS.

to form a kind of wall, sometimes so thin that it is
actually pierced by a natural hole, as for instance
the Martinsloch above Elm, in Glams. There is
another of these orifices near the summit of the
Pilatus, one in the Marchzahn, a mountain of the
Gastlose chain, and another in the Piz Aela, also
known for that reason as Piz Forate, between the
Albula and the Oberhalbstein Rhine.*

When we look at these abrupt folds and com-
plicated contortions, the first impression is that they
must have been produced before the rocks had
solidified. This, however, is not so. They could not
indeed have been formed except under pressure.
We must remember that these rocks, though they
are now at or near the surface, must have been
formerly at a great depth, and where the pressure
would be tremendous. Even in tunnels, which of
course are comparatively near the surface, it is some-
times found necessary to strengthen and support the
walls which would otherwise be crushed in. The
roadways in coal-mines are often forced up, especially
where two passages meet. This indeed is so com-
mon that it is known as the “creeps.” In deep
tunnels it has not unfrequently happened that when
strata have been uncovered they have suddenly bent
* Theobald’s Graubiinden, Beitr. z. Geol. Karte d. Schw n.

SCENERY OF SWITZERLAND.

and cracked, which shows that they were under
great lateral pressure. Yet the deepest mine only
reaches 800 metres.

Treska* has shown by direct experiment that
the most solid bodies, lead, tin, silver, copper, and
even steel, will give way and “flow” under a pressure
of 50,000 kilograms per square centimetre. More-
over, there is direct and conclusive evidence that the
Swiss rocks were folded after solidification. Tn many
cases contorted rocks contain veins (Fig. 16) which
are in fact cracks filled up with calcite, etc. Such
fine fissures, however, can only occur in hard rock.
Again the Eocene contains rolled pebbles ot Gneiss,
Lias, Jurassic, etc., which must therefore have be-
come hard and firm before the Eocene period,**
while the folding did not occur till afterwards. It is
clear therefore that when the folding took place the
rocks were already solidified. No doubt, however,
the folding was a very slow process. It took place,
and could only take place, deep down, far below the
surface, under enormous pressure, and where the
material was perhaps rendered somewhat more plastic
by heat. In the later and higher rocks we find com-
pression with fracture, in the earlier and lower rocks

* Comptes Rendtis, 1874.

** Heim, Mech. d. Gebirgsb., vol. n.

THE ORIGIN OF MOUNTAINS.

compression with folding. Whenever we find a fold
we may be sure that, when formed, it was deep
down, far below the surface.

In fact folds and fractures are the two means by
which the interior strains adjust themselves. They
replace one another, and in the marvellously folded
districts of the Alps faults are comparatively few,
though it must not be supposed that they do not
occur. The nature of the rock has little influence on
the great primary folds, but the character of the
minor secondary folds depends much upon it.

Fig. 15 represents a piece of contorted mica
schist, and it will be seen that the folds are a minia-
ture of those to which on a great scale our mountains
are due.

Many of the following figures give an idea of
the remarkable folds and crumpling which the strata
have undergone, so much so that they have been
compared to a handful of ribbons thrown on to the
ground.

It is obvious that before strata could be thrown
into contortions such as these, they must have been
subjected to tremendous pressure. They have conse-
quently been much altered, and the fossils have been
compressed, contorted, crushed, ground, and partly,
or in many cases entirely, obliterated.

SCENERY OF SWITZERLAND.

Fig. 15. — Hand Specimen of Contorted Mica Schist.

to a few metres.* In other cases certain formations
have been completely squeezed out. We must not
* Heim, Mech. d. Gebirgsb., vol. 11.

In parts of the great Glarus fold (see vol. 11. p. 64)
the Hochgebirgskalk is reduced from a thickness of 450

THE ORIGIN OF MOUNTAINS.

therefore infer, from the absence of a given stratum
in such cases, that it never existed.

In many cases the rock is broken up into flat or
more or less lenticular pieces, which have been
squeezed over one another so that their surfaces
have been rendered smooth and glistening. Such
surfaces are known as slickensides. This process has
sometimes been so intense and so general that hardly
a piece can be found which does not present such a
polished surface. The particles of stone which now
touch were once far apart, others which are now at
a distance once lay close together. The cracks, move-
ments, and friction which result in such a structure
must from time to time produce sounds, and the
mysterious subterranean noises sometimes heard are
perhaps thus produced.

Fig. 1 6 represents a section of Rothidolomite,
and it will be observed that, as we should expect
theoretically (see also Fig. 12 , p. 68), the strata are
thinnest in the limbs, where they are squeezed out,
and broader in the arches. This is visible in great
mountain folds, as well as in hand specimens.

In the part of the curve where the effect of the
force is to draw out the strata, they will as shown
above, if capable of giving way, become thinner. If
however they are not plastic they must crack, the

SCENERY OF SWITZERLAND.

combined width of the cracks affording the additional
space. Fig. 17 represents a fragment of Verrucano
thus drawn out.

Fig. 16 . — Suction of Rothidolomite.

In many cases fossils are compressed or torn,
but still distinguishable. Fig. 18 represents Belem-

Fig. 17. — Piece of Stretched Verrucano.

nites thus compressed and torn; but in all these

THE ORIGIN OF MOUNTAINS.

cases the extension or tear-
ing is due, not to a genera!
extension of the rock, but
to lateral thrust.

Fig. 1 9 represents a piece
of nummulitic limestone in
which the rock has not only
been fractured along the
lines a b, but two sides of
the vein a have been evi-
dently displaced. At a later
date another fracture has
taken place along the line c d.

Some rocks have been
so kneaded and ground to-
gether that in many places it
is rare to find a cubic milli-
metre next its original neigh-
bours.* In many places frag-
ments and wedges of one
formation have been forced
into another.

In the Tertiary slates
of the Sernfthal at Platten-

* Heim, Mech. d. Gi'lirgsb,,

vol. i.

Fig. 18. — Stretched and broken Eclemnitcs, J /. 2 size. A, Belemnites hastilis, slightly broken, Frete dc Saille. B, Specimen

much drawn out. C, Section at n.

SCENERY OF SWITZERLAND.

berg near Matt are well-preserved remains of fish
belonging to the genus Lepidotus. Agassiz thought
he could distinguish, and described, six species, but
Wettstein has shown that they all belong to one and
the same, and that the differences of form are
merely due to the position in which the specimens

Fig.

happened to lie with reference to the direction of
pressure.

In many cases the pressure has produced
“cleavage,” and turned the rocks into slate,* so that
they split into more or less perfect plates or films.
The direction of cleavage is quite independent of

* English geologists apply the term “shale” to rocks which
split along the laminae of original deposition, and which are
comparatively soft and destructable, and “slate” to those where
the lamination is due to cleavage. Continental geologists gener-
ally include shales and slates under the same name.

THE ORIGIN OF MOUNTAINS.

the stratification, which it may cross at any angle.
Heim distinguishes three forms of cleavage. Firstly,
that due to the formation of slickensides as just
described (ank, p. 75). The second kind of cleav-
age is due to the minute particles in the rock being
flattened by, and arranged at right angles to, the
pressure, as shown in Figs. 20 and 21.*

The third is produced by all the laminae or
elongated particles being arranged by the pressure
in lines of least resistance, so that they are forced to
lie parallel to one another.

It is, however, by no means always easy, especi-
ally in the crystalline rocks, to distinguish cleavage
from stratification. The structure of the rock, which
forms the base of the Windgalle, and which Heim
regards as partly stratification, is considered by some
geologists to be all cleavage.

The fact that cleavage has been produced by
pressure was first demonstrated by Sharpe, and after-
wards with additional evidence by Sorby and Tyndall.
In fact, under great pressure solid rock behaves very
much like ice in a glacier.

Cleavage and folding are both due to the same

* Geikie, 7'ext-book of Geology.

80 SCENERY OF SWITZERLAND.

cause. They have arisen simultaneously, and are

Fig. 20.— Section of a fragment of argillaceous rock.

different manifestations of the same mechanical ac-
tion.

Fig. 21. — Section of a similar rock Which has been compressed, and
in which cleavage structure has been developed.

THE MOUNTAINS OF SWITZERLAND.

8 I

CHAPTER III.

THE MOUNTAINS OF SWITZERLAND.

Erst dann haben wir ein Gebirge erkanut, wenn sein Inneres
durclisichtig wie Glas vor unserem geistigen Auge ersclieint.

Theobald.

We do not really know a mountain until its interior is to
our mental eye as clear as crystal.

The Swiss mountains, as indicated in the preced-
ing chapter, are now considered to be due, not to
upheaval from below, but to lateral pressure.

This acted from the south-east to north-west, and
took place at a comparatively recent period, mainly
however after the end of the Eocene period. There
are good grounds for supposing that a former range
occupied the site of the present Alps at an early
period, and the Carboniferous strata show consider-
able folds (Fig. 22), over which the Permian and
more recent strata were deposited.

The Carboniferous Puddingstone of Valorsine,
which contains well-rounded pebbles and boulders,
shows that there must have been mountains and

Scenery of Switzerland. I.

SCENERY OF SWITZERLAND.

rapid rivers at this period. These ancient mountains,
however, were removed by denudation, and the
whole country sunk below the Sea. Between the
Eocene and the Miocene was a second period of
disturbance, and all the strata, including the Eocene,
were folded conformably together.* The main eleva-
tion of the Alps was, however, between the Miocene

Fig. 22. —Carboniferous Folds on the Bilerten Grat.

and the Glacial periods. Miocene strata attain in
the Rigi a height of 6000 feet. By this much at
least then the Alps must have been raised since the
close of this comparatively recent period.

“It is strange to reflect,” says Geikie, “that the
enduring materials out of which so many of the
mountains, cliffs, and pinnacles of the Alps have been
formed are of no higher geological antiquity than the

* Heim, Mech. d. Qebirgsb., vol. 1.

THE MOUNTAINS OF SWITZERLAND. 83

London Clay and other soft Eocene deposits of the
South of England.” *

Unfortunately we seldom see a map, except on
quite a small scale, of the whole Alps. We have
separate maps of France, of Switzerland, of Italy, and
of the Austrian dominions. But to get a good general
idea of the whole Alps, we require not only Switzer-
land, but parts of France, Italy, and Austria. If we
have such a map before us we see that, with many
minor irregularities, the Alps are formed on a de-
finite plan.

The principal axis follows a curved line en-
circling the North of Italy; commencing with a direc-
tion almost due north in the Maritime Alps, sweeping
round gradually to the east. The direction appears
to have been determined by the pre-existing Central
Plateau of France and the Black Forest, which pro-
bably formed a continuous barrier before the sub-
sidence of the Rhine valley. They are in fact ancient
pillars, far older than the Alps, and Switzerland has
been thrown into waves or folds by compression
against these great buttresses.

“To account for the conformation of the Alps,”
says Tyndall, “and of mountain regions generally,
constitutes one of the most interesting problems of

* Geikie’s Text-book of Geology.

6 *

8 4

SCENERY OF SWITZERLAND.

the present day. Two hypotheses have been ad-
vanced, which may be respectively named the hypo-
thesis of fracture and the hypothesis of erosion.
Those who adopt the former maintain that the forces
by which the Alps were elevated produced fissures
in the earth’s crust, and that the valleys of the Alps
are the tracks of these fissures. Those who hold the
latter hypothesis maintain that the valleys have been
cut out by the action of ice and water, the moun-
tains themselves being the residual forms of this
grand sculpture. To the erosive action here in-
dicated must be added that due to the atmosphere
(the severance and detachment of rocks by rain and
force), as affecting the forms of the more exposed
and elevated peaks.”*

This was written thirty years ago and has been
confirmed by the subsequent researches of geologists.
While the folding referred to in the last chapter has
elevated the ranges and determined the position of
many of the Swiss valleys, “fracture” has played but
a subordinate part, and to denudation and erosion,
as Tyndall himself always maintained, the present
conformation of the country is mainly due.

* Tyndall, “Conformation of the Alps,” Philosophical Mag.,
Oct. 1864. See also Scrope, “On the Origin of Valleys,” Geol.
Mag. 1866.

THE MOUNTAINS OF SWITZERLAND.

Switzerland is divided roughly into equal parts
by four great rivers, — the Rhine, the Rhone, the
Reuss, and the Ticino. These four rivers rise on the
same great “central massif.” The valleys are not,
however, of the same character. The Rhine-Rhone
valley from Martigny to Chur is a “geotectonic”
valley; its direction coincides with the direction or
“strike” of the strata, and it was originally deter-
mined by a great fold in the strata.

The Reuss and Ticino valleys (except the upper
part of the Reuss in the Urserenthal, which is in fact
a part of the Rhone-Rhine valley and the upper part
of the Ticino in the Val Bedretto, which is also a
longitudinal valley) are transverse; they cross the
strata approximately at right angles, and consequently
the rocks on the two sides are the same. They are
entirely or almost entirely due to erosion.

In the Jura, where the foldings are comparatively
gentle and the denudation has been much less, the
present configuration of the surface follows more
closely the elevations and depressions due to geo-
logical changes (see Fig. 5).

In the Alps the case is different, and the de-
nudation has so far advanced that we can at first
sight trace but little relation between the valleys, as
indicated by the river courses and the mountain

SCENERY OP SWITZERLAND.

chains, and the geological structure of the country.
There are many cases of anticlinal valleys; that is to
say, of valleys (see ante, p. 70) which run along what
was at one time the summit of an arch, as, for in-
stance, the Maderanerthal (Fig. 24) and the Val de
la Tiniere (Fig. 98).

In other cases a piece is cut off from the rest
of the massif to which it belongs, as, for instance,
the Frusthorn from the Albula massif by the Valser-
thal.

I here are others where a mountain, or range of
mountains, occupies the line of a former valley. This
is the case for instance with the mountain ridge
which runs between the Rhine and the upper Linth
from the Kistenpass at the head of the Limmerbach
to the south of the Limmern Glacier, by the Biferten-
stock to Piz Urlaun and Stock Pintga or the Stock-
er 011 ’* Phis range of mountains occupies the site of
an original valley, but no doubt from the greater
hardness of the rock and its position it has offered
a more successful resistance to attack; while the
oiiginal mountains have been washed away.

In this way some at anyrate of the transverse
langes have, as it were, been carved out. Thus the
Safienthal — the valley of the Glenner which falls into
Heim, Beitr. z. Geol. K. d. Sc/iw., L. xxv.

THE MOUNTAINS OF SWITZERLAND.

the Rhine at Ilanz — is bounded by ranges ap-
proximately at right angles to the main direction of
the mountains. That on the left of the valley cul-
minates in the Piz Ricin, Crap Grisch, Weissenstein-
horn, and Barenhorn. In favourable light it can
easily be seen from the opposite side of the valley,
that the streams have cut out the valleys and are
thus the cause of the mountains. This is a par-
ticularly clear illustration, because the strata are
uniform along the whole line, so that the structure is
not complicated by the presence of rocks of different
character and hardness.

Indeed if we compare together two maps, in one
of which the principal chains of mountains, and in
the other the main river valleys, are brought out
most prominently, they look at first sight so different
that we should hardly suppose them to represent the
same district.* It is evident therefore that the main
agent which has determined the longitudinal valleys
is not that which has given rise to the mountain
summits. The courses of the rivers, though there
have, as we shall see, been many minor changes, and
exceptions due to other causes, still were determined
by the folds into which the surface was thrown; while

* Heim, Mech. d. Gebirgsb., vol. I.

SCENERY OF SWITZERLAND,

the present mountain summits are mainly the result
of erosion and denudation.

We will now consider the evidence which leads
to the conclusion that the fossiliferous strata formerly
extended over the Central chain of the Alps. It is
a common error to suppose that the limits of
geological strata are those which are now shown on
the map. It requires little reflection however to
show that this was not so. In the abyssal depths of
the ocean deposit is portentously slow, and a long
period would be represented by only a few inches of
rock. Moreover, though a marine formation proves
the existence of sea, the absence of a marine forma-
tion does not prove the existence of land. Strata
may and often have been entirely removed. Our
Cretaceous deposits, for instance, once extended far
beyond their present limits. The same was the case
with the Secondary deposits of Switzerland from the
I rias to the Eocene. They extended completely over
the Central mountains. If these mountains had been
then in existence and the Secondary strata had been
deposited round them, we should find evidence of
shore deposits, with remains of animals and seaweeds
such as live in shallow waters and near land. This
is however not the case; we find no pebble beds
such as would be the case near a shore, no gravels

THE MOUNTAINS OF SWITZERLAND. 89

with pebbles of granite, gneiss, or crystalline schists,
but deep-sea deposits of fine sediment evidently
formed at some distance from land. In the Triassic
period there seems to have been a barrier between
the Eastern and Western Alps, but subsequently the
conditions must have been very similar, and the
southern shores of the Jurassic Sea were perhaps far
away in Africa.*

Even the Eocene deposits show no evidence of a
shore where the Alps now rise above them.

We have other proofs that the central chains
were formerly covered by other strata. For instance,
the Puddingstone of Valorsine at the head of the
Chamouni valley, which belongs to the Carboniferous
period, contains no granite or porphyry pebbles. The
granite and porphyry strata of the district must there-
fore at that period have been protected by a cover-
ing of other rocks which have been since stripped off.

It is also significant that the pebbles of the Mio-
cene Nagelflue which come from the neighbourhood
are mainly of Eocene age. Neither the Crystalline
rocks nor the older Secondary strata seem to have
been then as yet uncovered.** There are indeed

* Heim, Meek. d. Gebirgsb vol. H.; Baltzer, Beitr. z
Geol. K. d. Schw L. xxiv.

** Heim, Mech. d. Gebirgsb ., vol. II.

SCENERY OF SWITZERLAND.

crystalline and Triassie pebbles in the Nagelflue, for
instance, of the Rigi, but they do not belong to rocks
found in the valley of the Reuss or on the St. Gott-
hard. They resemble those of Lugano, Bormio,
the Julier, and other districts far away to the south-
east.

We are not however dependent on these argu-
ments alone, conclusive as they are. Remains of
Secondary strata occur here and there in the Central
district, and these are not fragments torn away from
one another, but parts of a formerly continuous sheet,
which have been preserved in consequence of being
protected in the hollows of deep folds. That the
Secondary strata were once continuous over the
Central chain is well shown in the following section
(Fig. 23) drawn from the Rhone to the Averserthal
and cutting the Binnenthal, Val Antigorio, Val Ba-
vena, Val Maggia, Val Ticino, Val Blegno, Val Mi-
socco and Val St. Giacome. It will be seen that all
these valleys are primarily due to great folds, and
that in each case we find at the bottom of the val-
leys remains of the Secondary strata nipped in be-
tween the Crystalline rocks.

Fig. 24 shows a section after Heim, from the
Weisstock across the Windgalle to the Maderaner-
thal. It is obvious that the valleys are due mainly

THE MOUNTAINS OF SWITZERLAND.

to erosion, that the Maderaner
valley has been cut out of the Crys-
talline rocks, f, and was once
covered by the Jurassic strata j,
which must have formerly passed in
a great arch over what is now the
valley.

Again it is clear (Fig. 25) that
a great thickness of Crystalline rock
has been removed from the summit
of Mont Blanc. No doubt (see ante,
p. 28) many thousand feet had been
removed before the deposition of
the Secondary strata. But even since
its elevation the amount of erosion
of the Granite itself has been con-
siderable. How much we do not
know, but 500 metres would pro-
bably be a moderate estimate. To
this must be added the Crystalline
Schists, say 1000 metres, and the
Sedimentary rocks, which from what
we know of their thickness elsewhere
cannot be taken at less than 3000
metres. This therefore gives 4500
metres, or say 14,000 feet, which

jSSw-g

rC cS ^ r

THE MOUNTAINS OF SWITZERLAND. 93

erosion and denudation have stripped from the
summits of the mountains! Fig. 26 gives a section
across the Alps, and it will be seen that the section
across the St. Gotthard substantially resembles that
of Mont Blanc.

Surprising, and even almost incredible, as this
may at first sight appear, it becomes less difficult to
believe when we remember that not only the great
Miocene gravel beds which form the Central plain of
Switzerland, but much of the deposits which occupy
the valleys of the Rhine, Po, Rhone, Reuss, Inn, and
Danube- — the alluvium which forms the plains of
Lombardy, of Germany, of Belgium, Holland, and of
South-east France consists of materials washed down
from the Swiss mountains.

It is calculated that at the present rate of erosion
the Mississippi removes one foot of material from its
drainage area in 6000 years, the Ganges above
Ghazipur in 800, the Hoangho in 1460, the Rhone
in 1500, the Danube in 6800, the Po in 750. Pro-
bably therefore we may take the case of the Rhone
as approximately an average, and this gives us, if not
a measure, at any rate a vivid idea of the immense
length of time which must have elapsed.

The great plain shows comparatively gentle eleva-
tions, which become more marked in the “Prealps,”

THE MOUNTAINS OF SWITZERLAND.

while the inner chains are thrown
into the most extreme contortions.
In some cases the result of com-
pression has been to push certain
strata bodily over others. Such over-
thrusts also greatly tend to render
the relief of the surface independent
of the tectonic structure. If there
were no overthrusts, if the arches
had been flatter and the troughs
broader, the causes which have led
to the present configuration of the
surface would have been much
clearer.

The main ranges then are due
to compression and folding, the
peaks to erosion, and the three main
factors in determining the physical
geography of Switzerland, have been
compression, folding, and denudation.

The present configuration of the
surface is indeed mainly the result
of denudation, which has produced
the greatest effect in the Central
portions of the chain. It is probable
that the amount which has been

SCENERY OF SWITZERLAND.

removed is nearly equal to that which still remains,*
and it is certain that not a fragment of the original
surface is still in existence, though it must not be
inferred that the mountains were at any time so
much higher, as elevation' and denudation went on
together.

The country is now, however, so well mapped
that if changes are still going on they must ere long
show themselves. It is probable on mechanical and
geological grounds that the southern chains were
formed first, and the northern ones afterwards in
order of succession. It has been shown that the
Secondary strata originally covered the whole area,
and their removal from the Central massives, except
in the deeper folds, is strong evidence of their great
age. This leads us to the consideration whether
changes of level are still taking place, There are
some reasons for doubting whether they have alto-
gether ceased, but as yet we have no absolute proof.

Slight earthquakes are common in Switzerland;
more than 1000 have been recorded during the last
150 years, and no doubt many more have passed
unnoticed. This appears to indicate that the forces
which have raised the Alps are perhaps not entirely

* Heim, Beitr. z. Geol. A. d. Sckw., L. XXV.

THE MOUNTAINS OF SWITZERLAND.

spent, and that slow movements may be still in pro-
gress along the flanks of the mountains.*

Many of these earthquakes are very local and as
a rule not deep seated, at a depth of not more than
from 1 5,000 to 20,000 metres.

Even however in the Central Alps there is some
evidence of present strain. When the tunnels were
being pierced for the St. Gotthard line, and especi-
ally the Wattinger tunnel near Wasen, slight ex-
plosions were often heard, and blocks of rock were
thrown down on the workmen. These generally came
from the roof, but sometimes from the sides, and
eventually it was found necessary to case the interior
of the tunnel.** These phenomena, however, may
have been only due to the great pressure.

The American geologists, and especially Dana,
have pointed out that folded mountains are not as a
rule symmetrical but one-sided. Suess*** has ex-
tended this to Switzerland, and indeed to folded
mountains generally. It is remarkable that in all the
European mountain systems — the Alps, Appennines,
Jura, Carpathians, Hungarian Mountains, etc., the
outer side of the curve presents a succession of folds

* Heim, Mech. d. Gebirgsb., vol. n.

** Baltzer, Beitr. z. Geol . B. d. Schw., L. XXIV.

*** Das Antlitz der Erde.

Scenery of Switzerland. I.

9 8

SCENERY OF SWITZERLAND.

which gradually diminish in intensity, while the inner
side terminates in an immense fold, the anticlinal, or
arch of which, in the case of Switzerland, constitutes
the outer crest of the Alps, while the synclinal, or
area of depression, has given rise to the great valley
of the Po, which appears to be an area of sinking.

The Jura rises gently from the north-west, and
culminates in the steep wall which bounds the Cen-
tral plain of Switzerland.

Ihe Ural Mountains and their continuation, the
Islands of Novaya Zemlya, are steep on the eastern
side. In fact, the Urals are not so much a chain of
mountains, as a tilted surface, with a sudden fracture,
and a sunken area to the east* The Indian Ghats
again present a very steep side to the sea. The
Himalayas (which in so many respects resemble the
Alps), the Rocky Mountains, the Green Mountains,
the Alleghanies, etc., are also one-sided, and South
America slopes up from the east to the great wall of
the Andes which towers over the Pacific Ocean.

The Alps are a most delightful, but most difficult,
study, and although we thus get a clue to the general
structure of Switzerland, the whole question is ex-
tremely complex, and the strata have been crumpled

Suess, Die Entstehung der Alpen.

THE MOUNTAINS OF SWITZERLAND.

and folded in the most complicated manner, some-
times completely reversed, so that older rocks have
been folded back on younger strata, and even in
some cases these folds again refolded.

IOO

SCENERY OF SWITZERLAND.

CHAPTER IV.

SNOW AND ICE. SNOWFIELDS AND GLACIERS.

“ Chaque annee je me livre a de nouvelles reclierches , et en
me procurant im genre de jouissance peu connu du reste des
hommes, cel ni de visiter la nature dans quelques-uns de ses
plus liauts sanctuaires, je vais lui demander l’initiation dans
quelques-uns de ses mysteres, croyant qu’elle n’y admet que
ceux qui sacrifient tout pour elle et qui rendent des liommages
continuels.” — Dolomieu, Journal des Mines , 1798.

The height of the snow-line in the Alps differs
according to localities and circumstances, but may
be taken as being from 2500 to 2800 metres above
the sea-level.

The snowfields are very extensive, the expanse
of firn being necessarily greater than that of the
glacier proceeding from it.

The annual fall of snow gives rise to a kind of
stratification, which however gradually disappears.
The action of the wind tends, on the whole, to level
the surface, leaving however many gentle undulations,
and heaping up the snow in crests and ridges. On
the creste of the mountains it often forms cornices,
which sometimes project several feet. I shall never

SNOW AND ICE.

IOI

forget my sensations, when standing with Tyndall on,
as I supposed, the solid summit of the Galenstock,
he struck his alpenstock into the snow, and I found
that we were only supported on such a cornice pro-
jecting over a deep abyss.

When the snow falls at a temperature of o°-i2°,
it assumes the form of stars or six-sided crystals.

The region affected by glacial action may be
divided into three parts: —

1. The firn or Nevd.

2. The glacier.

3. The region of deposit.

The Firn or Neve.

The snow which falls in the higher Alpine regions,
by degrees loses its crystalline form, becomes granular,
and is known as Neve or Firn. It can be dis-
tinguished at a glance from recent snow by being
less brilliantly white, partly because it contains, less
air, partly because the particles of meteoric and
other dust give it a lightly yellowish, grey, or even
brownish tinge. Sometimes it is in patches quite
red. This is generally due to the presence of a
minute alga (Sphierella nivalis). There are, however,
several other minute organisms, plants, Infusoria and

102

SCENERY OF SWITZERLAND.

Rotifera (Philodina roseola) of a red or brownish
colour. The firn is generally firm. When the tempera-
ture is low, it becomes quite hard; except on hot
days the foot sinks but little into it; usually it re-
mains dry. The water which results from melting
sinks into it, and freezes the snow below into a solid
mass, which has a more or less stratified appearance,
each yearly deposit forming a layer from one to three
feet in thickness, which can sometimes be traced even
to the lower end of the glacier. The firn attains in
many places a great depth. Agassiz estimated that
of the Aar glacier at 460 metres .* It moves slowly
downwards, and when its upper end terminates
against a rock wall, which of course retains its posi-
tion, a deep gap is formed in spring, known as a
Bergschrund, which widens during the summer and
autumn, gradually fills up in winter, and reappears
the next year.

It is impossible to give any idea in words of the
beauty of these high snowfields. The gently curving
surfaces, which break with abrupt edges into dark
abysses, or sink gently to soft depressions, or meet
one another in ridges, the delicate shadows in the
curved hollows, the lines of light on the crests, the
suggestion of easy movement in the forms, with the
* Systems Glaciaire .

SNOW AND ICE.

103

sensation of complete repose to the eye, the snowy
white with an occasional tinge of the most delicate
pink, make up a scene of which no picture or photo-
graph can give more than a very inadequate impres-
sion, and form an almost irresistible attraction to all
true lovers of nature.

The snow would accumulate and increase in
thickness indefinitely if it were not removed, (1) by
melting and evaporation, (2) by avalanches, and (3)
by slow descent into the valley.

Avalanches.

Avalanches may be divided into two principal
classes; dust avalanches, and ground avalanches.

Dust avalanches generally occur after heavy snow-
falls and in still weather, because the snow ac-
cumulates on steep slopes until it finally gives way;
first in one place and then in another; first slowly,
then more rapidly, until at last it rushes down with
a noise like thunder.

The falling mass of snow compresses the air,
and makes a violent wind, which often does more
mischief than the actual avalanche itself. A great
part of the snow rests at the foot of the declivity
from which it falls, but a part is caught up by the
wind and carried to a considerable distance. Such

I°4 SCENERY OF SWITZERLAND.

avalanches fall irregularly, as they depend on a
variety of circumstances; they cannot therefore be
foreseen, and do much damage, often killing even
wild animals.

Ground avalanches occur generally in spring, when
the snow is thawing. The water runs off under the
snow, which thus becomes hollow, only touching the
ground in places. A slight shock is sufficient to set
it in motion, and it tears away down to the ground,
which it leaves exposed. Such avalanches depend
therefore on the configuration of the surface, and are
in consequence comparatively regular. In many
cases they follow the same course year after year.
In these tiacks, trees cannot grow, but only grass or
low bushes.

The front part of the avalanche of course first
begins to slacken its speed. The part behind then
presses on it, and often pushes over it. Those who
have been enveloped in an avalanche all agree, that
during the motion they could move with comparative
freedom, then at the moment of stopping came ex-
treme pressure, and they found themselves suddenly
encased in solid ice. Pressure had caused the
particles to freeze suddenly.

Avalanches are often looked on as isolated and
exceptional phenomena. This is quite a mistake.

SNOW AND ICE.

105

They are an important factor in Alpine life. The
amount of snow which they bring down is enormous.
Coaz* estimates it in certain districts as equal to
1 metre of snow over the whole district. Without them
the higher Alps would be colder, the lower regions
hotter and drier. The snow-line would come down
lower, many beautiful Alps would be covered with
perpetual snow, the glaciers would increase, the
climate become more severe, the mountains less
habitable. To appreciate the importance of ava-
lanches one must ascend the mountains on a warm
day in spring. From every cliff, in every gorge we
hear them thundering down all round us. They
descend on all sides like hundreds of waterfalls,
sometimes in a silver thread, sometimes like a broad
cataract. The mountain seems to be shaking off its
mantle of snow.

However destructive then they may be at times,
avalanches are on the whole a blessing.**

Glaciers.

By the slow action of pressure, and the percola-
tion of water, which freezes as it descends, the firn
passes gradually into ice. In cool and snowy

* Die Lawinen in den Schweizercilften , Bern, 188 1,

** Heim, Gletsclierkunde .

io6

SCENERY OF SWITZERLAND.

summers the thickness of the layer of firn increases.
It is deepest in the higher regions, and thins out
gradually, until at length ice appears on the actual
surface, and the firn passes into a glacier.

Glaciers are in fact rivers of ice, which indeed
sometimes widen out into lakes. Glacier ice differs
considerably from firn ice, and the molecular process
by which the one passes into the other is not yet
thoroughly understood. Again, if a piece of ice from
a lake is melted in warm air the surface gradually
liquefies and the whole remains clear; on the con-
trary, a piece of compact glacier ice from the deeper
part of a glacier if similarly treated behaves very
differently; a number of capillary cracks appear,
which become more and more evident, and gradually
the ice breaks up into irregular, angular, crystalline
fragments. These are known as the “grains du
glacier” or “Gletscherkorn,” and were first described
by Hugi* They increase gradually in size, but how
this growth takes place, and whether they are derived
from the granules of the firn, is still doubtful. When
the firn passes into the glacier they may be about
1 / i inch across; in the middle part of a large glacier
about the size of a walnut, and at the end 4 or even
6 inches in diameter. Those at the end of the Rhone
* Das Wescn der Gletscher, 1842 .

SNOW AND ICE.

107

Glacier vary much in size, but the majority are under
an inch across.

In some cases they are tolerably uniform in size,
in others large and small are mixed together. On
any clean surface of glacier ice they are easily visible,
as for instance in the ice tunnel which is so often
cut at the end of glaciers. Their surfaces present a
series of fine paralled striae , first noticed by Forel.
Glacier ice then may be said to be a granular aggre-
gate of ice crystals. By alternately warming and
cooling snow, and saturating it repeatedly with water,
Forel found that he produced an ice very similar in
structure to that of glaciers. There seems no doubt
that this structure considerably facilitates the move-
ments of glaciers.*

Glaciers are generally higher in the middle, and
slope down at the two sides owing to the warmth
reflected from the rocks. When the valley runs
north and south the two sides are equally affected in
this respect; but when the direction is east to west
or west to east the northern side is most inclined
because the rocks lie more in the sun, while those to
the south are more in the shade.

* Heim, Gletscherkunde .

io8

SCENERY OF SWITZERLAND.

Movememt of Glaciers.

Rendu, afterwards Bishop of Annecy, in 1841
first stated clearly the similarity between the move-
ments of a river and those of a glacier.

Subsequent observations have confirmed Rendu’s
statements. In fact the glacier may be said really to
flow, though of course very slowly.

The movement of a glacier resembles that of a
true river, not only generally, but in many details;
the centre moves more quickly than the sides; where
the course curves, the convex half moves more
quickly than the concave, and the surface more
quickly than the deeper portions. The movement is
more rapid, indeed some three times more quick, in
summer than in winter.

The first detailed observations on the movements
of glaciers were made independently and almost
simultaneously by Agassiz on the Unter-Aar glacier,
and by Forbes on the Mer de Glace.

The yearly motion of the Swiss glaciers is es-
timated at from 50 to 130, or in some exceptional
cases even 300 metres. The rapidity differs however
considerably, not only in different glaciers, but in
different parts of the same glacier; in different years,
and different times of year. The remains of Dr.

SNOW AND ICE.

IO9

Hamel’s guides, who perished in a crevasse on the
Grand Plateau (Mont Blanc) on 20th August 1820,
were found in 1861 near the lower end of the
Glacier des Boissons, having moved some 4 miles in
forty-one years, or nearly at the rate of about 500 feet
a year.

It has been calculated that a particle of ice
would take at least 250 years to descend from the
Strahleck to the lower end of the Under-Aar Glacier;
from the summit of the Jungfrau to the end of the
Aletsch Glacier about 500 years.

During the Middle Ages the Swiss glaciers appear
on the whole to have been increasing in size, and to
have reached a maximum about the year 1820.
After that they retreated till about 1840, when they
again advanced until about i860, since which time
they have greatly diminished, though some are now
again commencing to advance. Those of northern
Europe appear to be also increasing.* It is, of
course, impossible to make any decided forecast as
to the future.

Cause of Movement.

But why do glaciers descend?

Scheuchzer in 1705 suggested that the water in
* Heim, Gletscherkunde.

SCENERY OF SWITZERLAND.

the fissures of the glaciers, freezing there and ex-
panding as it froze, was the power which urged
them forwards. Altman and GrUner in 1760 en-
deavoured to explain it by supposing that the glaciers
slid over their beds; and no doubt they do so to
some extent, but this is quite a subordinate form of
movement. Bordier regarded the ice of glaciers
“not as a mass entirely rigid and immobile, but as a
heap of coagulated matter or as softened wax, flexible
and ductile to a certain point.” This, the “Viscous”
theory, was afterwards most ably advocated by Forbes.
No doubt the glacier moves as a viscous body would;
but the ice, far from being viscous, is extremely
brittle. Crevasses begin as narrow cracks which
may be traced for hundreds of yards: a slight dif-
ference of inclination of the bed will split the ice
from top to bottom. It is, in fact, deficient in that
power of extension, which is of the essence of a
viscous substance.

The explanation now generally adopted is that
which we owe mainly to Tyndall. Faraday in 1850
observed, that when two pieces of thawing ice are
placed together they freeze at the point of contact.
Most men would have passed over this little observa-
tion almost without a thought, or with a mere feeling
of temporary surprise. Eminent authorities have

SNOW AND ICE.

I I I

differed in the explanation of the fact, but into this
part of the question I need not now enter. Sir
Joseph Hooker suggested the term “Regelation,” by
which it is now generally known, and Tyndall has
applied it to explain the motion of glaciers.

Place a number of fragments of ice in a basin
of water, and they will freeze together wherever they
touch. Again, a mass of ice placed in a mould and
subjected to pressure breaks in pieces, but as the
pieces reunite by regelation they assume the form of
the mould, and by a suitable mould the ice may be
forced to assume any given form. The Alpine val-
leys are such moulds. When subject to tension, the
ice breaks and crevasses are formed, but under
pressure it freezes together again, and thus preserves
its continuity.

Professor Helmholtz in his scientific lectures sums
up the question in these words — “I do not doubt
that Tyndall has assigned the essential and principal
cause of glacier-motion, in referring it to fracture and
regelation.” Other authorities, however, do not re-
gard the problem as being yet by any means solved.*
Heim points out that, as in the case of water, a
large glacier moves under similar conditions more

* Heim, Gletscherkimde.

II 2

SCENERY OF SWITZERLAND.

rapidly than a small one. Many bodies will in small
dimensions retain their form, which in larger masses
would be unable to support their own weight. A
small clay figure will stand where a life-sized model
will require support. Sealing-wax breaks under ten-
sion like ice, but under even slight pressure gradually
modifies its form.

Prof. Heim is convinced that if a mass of lead,
corresponding to a glacier, could be placed in a Swiss
valley, it would move to a great extent like a glacier.
The size of a glacier is therefore an important factor
in the question, and throws light on the more rapid
movement of the greater glaciers, even when the in-
clination of the bed is but slight. In Heim’s opinion
then the weight of the ice is sufficient to account for
movement, though the character of the movement
and the condition of the glacier is due to fracture
and regelation. He sums it up in the statement
that gravity is the moving force, and the glacier
grains the prevailing mechanical units of movement.

Crevasses.

The rigidity of ice is well shown by the exist-
ence of crevasses. They may be divided into three
classes: —

SNOW AND ICE.

I 13

1. Marginal.

2. Transverse.

3. Longitudinal.

The sides of most glaciers are fissured even when
the centre is compact. The crevasses do not run in
the direction of the glacier, but obliquely to it, en-
closing an angle of about 45 0 (Fig. 29, m m ) and
pointing upwards, giving an impression that the centre
of the glacier is left behind by the quicker motion
of the sides. This was indeed supposed to be the
cause, until Agassiz and Forbes proved that, on the
contrary, the centre moved most rapidly. Hopkins
first showed that the obliquity of the lateral crevasses
necessarily followed from the quicker movement of
the centre.

Tyndall gives the following illustration: — “Let
A C, in the annexed figure, be one side of the
glacier, and B D the other; and let the direction of
the motion be that indicated by the arrow. Let T
be a transverse slice of the glacier, taken straight
across it, say to-day. A few days or weeks hence
this slice will have been carried down, and because
the centre moves more quickly than the sides it will
not remain straight, but will bend into the form S' T' .

“Suppose Ti to be a small square of the original
slice near the side of the glacier. In its new posi-

Scenery of Switzerland. /. 8

114 SCENERY OF SWITZERLAND.

tion the square will be distorted to the lozenge-
shaped figure T i' . Fix your attention upon the
diagonal T i of the square; in the lower position this
diagonal, if the ice could stretch, would be lengthened
to T’ i . But the ice does not stretch, it breaks, and
we have a crevasse formed at right angles to T’ i’ .
The mere inspection of the diagram will assure you
that the crevasse will point obliquely upward.”

a s S' c

Marginal crevasses then arise from the movement
of the glacier itself; transverse and longitudinal cre-
vasses are caused by the form of the valley. If the
inclination of the bed of a glacier increases, even if
the difference be but slight, the ice is strained, and,
being incapable of extension, breaks across. Each
fresh portion as it passes the brow snaps off in turn,
and thus we have a succession of transverse cre-
vasses. In some cases these unite with the trans-
verse fissures, thus forming great curved crevasses,

SNOW AND ICE.

115

stretching right across the glacier, and of course
with the convexity upwards.

Longitudinal crevasses occur wherever a glacier
issues from a comparatively narrow defile into a
wider plain. The difference of inclination checks its
descent; it is pushed from behind, and having room
to expand it widens, and in doing so longitudinal
crevasses are formed.

The sides of crevasses are of a brilliant blue, and
often look as if they were cut out of a mass of beryl.
The mountaineers have a traditon that glaciers will
tolerate no impurity, and though this is not of course
a correct way of stating the question, as a matter of
fact the ice is of great purity.

Veined Structure.

Glacier ice very often looks as if it had been
carefully and regularly raked. It presents innumer-
able veins or bands of beautifully blue dear ice, run-
ning through the general mass, which is rendered
whitish by the presence of innumerable minute air-
bubbles. The blue plates are more or less lenticular
in structure, sometimes a few inches sometimes many
yards in length, but at length gradually fade away.

The whole surface of the glacier in such parts is
lined with little grooves and ridges, the more solid

SCENERY OF SWITZERLAND.

1 16

blue veins projecting somewhat beyond the whiter
ice. This structure is very common, though present-
ing different degrees of perfection in different glaciers,
and different parts of the same glacier. It is rendered
the more conspicuous, because the fine particles of
dirt are naturally blown, and washed into the furrows.
The veins are often oblique, in many cases trans-

Fig. 28. — Section of Icefall, and Glacier below it, showing origin of
Veined Structure.

verse, in some longitudinal, and in others vary in
different parts of the glacier.

Here also we owe, I think, the true explanation
to Tyndall. We will begin with the oblique veins,
which are most marked at the sides, and fade away

SNOW AND ICE.

1 1 7

towards the centre of the glacier. Tyndall points out
that if a plastic substance, such as mud, be allowed
to flow down a sloping canal, the lateral portions,
being held back by the sides, will be outstripped by
the centre. Now if three circles (Fig. 29) be stamped
on the mud-stream, the central one will retain its
form, but the two lateral ones will gradually elongate.
The shorter axis in 1 n m of each oval is a line of
pressure, the longer is a line of strain, consequently

1 1

' r ‘

P ii

0 Tzmm

Fig. 29.

along the line ni m, or across the tension, we have,
as already explained, the marginal crevasses; while
across the line, or perpendicular to the pressure, we
have the veined structure, which is in fact a form of
cleavage. Indeed, tension and pressure go together,
the one acting at right angles to the other. Passing
to the cases of transverse veining, we find if we walk
up a glacier presenting this structure that we eventu-
ally come to an ice-fall or cascade. At the foot of
the fall the ice is compressed, and this gives rise
to transverse veining. Longitudinal veining in thd

1 1 8

SCENERY OF SWITZERLAND.

same manner arises when two glaciers meet, as for
instance the Talefre and the Lechaud (Fig. 30),
where we have transverse pressure and in con-

Mont

Tacul

m 'M

' 4mm

c/e Periads

Fig. 30. — Sketch Map of tho-Mer de Glace.

sequence longitudinal veining. How great must be
the pressure in such cases we can faintly realise if
we bear in mind that the glaciers which unite to
form the great Gorner Glacier have a width of 5200

SNOW AND ICE.

metres which is compressed to 1000 and further on
to 500 metres.

The pressure acts on the ice in two ways
Firstly, in the same manner as it produces lamination
in rocks; and secondly, by partially liquefying the
ice, thus facilitating the escape of the air-bubbles,
which causes its whitish appearance.

Liquid Disks.

The Solar beams also form innumerable liquid
disks. As the water occupies less space than the
ice each disk is accompanied by a small vacuum,
which shines like silver, and is often taken for an
air-bubble.

Dirtbands.

If we look down on the Mer de Glace we see
(Fig. 30) a series of grey, curved, or bent bands,
which follow each other in succession from Trelaporte
downwards.

These “dirtbands” have their origin at the ice
cascade upon the Glacier du Geant. The glacier is
broken at the summit of the ice-fall (Fig. 28), and
descends the declivity in a series of transverse ridges.
Dust, etc., gradually accumulates in the hollows, and
though the ridges are by degrees melted away and

120

SCENERY OF SWITZERLAND.

finally disappear, the dirt remains, and forms the
bands. They are therefore quite superficial. Similar
bands occur on other glaciers with ice cascades,
and as many as thirty to forty may sometimes be
traced.

Moulins.

At night and in winter the glaciers are solemn
and silent, but on warm days they are enlivened by
innumerable rills of water. Sooner or later these
streams reach a crack, down which they rush, and
which they gradually form into a deep shaft. These
are known as glacier mills or Moulins. Of course
the crack moves down with the glacier, but the same
cause produces a new crack, so that the process re-
peats itself over and over again, at approximately
the same place. A succession of forsaken Moulins
is thus formed. Moulins are often very deep. Desor
sounded one on the Finster-Aar glacier which had a
depth of 2 32 metres.

The so-called Giants’ caldrons, which will be de-
scribed further on, are sometimes regarded as in-
dications of ancient glacial action. In the so-called
“glacier garden” at Lucerne this no doubt is so; but
as a general rule they were probably formed by river
action.

SNOW AND ICE.

12 I

In the larger glaciers most of the subglacial
rivulets unite under the glacier and flow out at the
end in a stream, often under a beautiful blue flat
arch generally from i to 3 but sometimes even 30
metres in height. In many cases it is possible to
enter them for some distance, and galleries are often
cut. The ice is a splendid blue, the surface takes a
number of gentle curves, and when the light from
outside is reflected from the surfaces, it assumes by
complementary action a delicate tint of pink.

Moraines.*

The mountain sides which surround glaciers
shower down on them fragments, and sometimes
immense masses, of rock, which gradually accumulate
at the sides and at the end, and are known as
“Moraines.” When two glaciers meet, a “medial”
moraine is formed by the union of two “lateial
moraines (Fig. 30), while the matter carried along
under the glacier is known as “ground Moraine.”
However many glaciers may unite, the moraines keep
themselves distinct, and may often be seen for miles
stretching up the glacier side by side.

* The word “Moraine” was adopted by Charpentier from
the local name used in the Yalais, and has now become general.

I 22

SCENERY OF SWITZERLAND.

Even from a distance we may often see by the
colour that different moraines, and the two sides of a
medial moraine, are composed of different rocks. On
the Aar glacier the left half of the medial moraine
is composed of dark micaceous Gneiss and Mica
Schist; the right half of white Granite. The right
lateral moraine of the Puntaiglas glacier, on the south
of the Todi group, is made up of dark greenish
Syenite and Granite, the first medial moraine is of
titaniferous Syenite, then comes a second of yellowish
red Rothidolomite with some Dogger; then several of
bluish black Hochgebirgskalk, and lastly the left
moraine is of Puntaiglas Granite, and various sedi-
mentary rocks from Verrucano to Eocene* The
Baltora glacier in the Hindu Kush has no less than
fifteen moraines of different colours. The different
moraines do not mix; and fragments from one side,
even of the same moraine, never pass to the other,
but move down with the ice, in the same relative
positions.

The glacier often rests directly on the solid rock,
but in many places there is a layer of clay and
stones, to which Ch. Martins gave the name of
“ground moraine,” and if the underlying rock is
examined it will be found to be more or less polished
* Heim, Gletscherkunde , p. 348.

SNOW AND ICE.

123

and striated. The importance of the ground moraine
was first pointed out by Martins* The pressure of
the glacier on its bed must be very great. On the
Aletsch glacier it has been calculated to be as much
as 4 tons to the square decimeter; under the Arctic
glaciers it must be much greater. In the winter
of 1844 some poles of timber were dropped under
the edge of the Aar glacier, in the following year
they were found to be crushed to small fragments.
Blocks of stone are gradually ground down and re-
duced to glacial mud. This is so fine that it re-
mains a long time in suspension in water, and gives
their milky colour to glacial streams. The ground
moraine is no doubt formed in some measure from
surface blocks which have found their way through
crevasses, and have to a great extent been crushed
and reduced to powder; but as ground moraines
occur under ice-sheets, such as that of Greenland,
when there are scarcely any surface blocks, it is
clear that the material is partly derived from the
underlying bed.

At the lower end of the glacier a terminal moraine
gradually accumulates, which may reach a height of
50, 100, or even 500 metres. They are more or
less curved, encircling the lower end of the glacier.

* Revue des Deux Mondes, 1847 .

124

SCENERY OF SWITZERLAND.

The quantity of debris differs greatly in different
glaciers: some, as the Rhone, Turtmann, etc., are
comparatively free, while others, as the Zinal and
the Smutt, have the lower ends almost entirely
covered.

It is difficult to give the actual number of glaciers
in Switzerland, because some observers would rank
as separate glaciers what others would consider as
branches, but the number may be taken as between
1500 and 2000. The total area is about 3500
sq. km.

The mean inclination of large glaciers is from 5 0
to 8°, falling however even to less than a degree.
The hanging glaciers are much steeper.

I he greatest thickness of the ice can only be
estimated. In one place of the Aar glacier Agassiz
found a depth of 260 metres without reaching the
bottom. From the transfiguration of the surface,
however, it may safely be calculated that the ice
must attain a thickness in places of 400 or even
500 metres. It has been calculated that the ice of
the Corner glacier would be enough to build three
Londons.

The distance to which a glacier descends depends
partly on the extent of the collecting ground, partly
on the configuration of the surface. The Gorner

SNOW AND ICE.

125

glacier advances so far on account of the magnitude
of the snow-fields above. In 1 8 1 8 the lower Grindel-
wald glacier descended to 983 metres above the sea
level. In 1870, it had receded to 1080 metres.
The lower limit of the Mer de Glace is 1120 metres.
In the Eastern Alps, where the climate is more con-
tinental and drier, the general limit is from 1800 to
2300 metres..

Ice Tables.

Small bodies, such as pebbles, dust, insects, etc.,
tend to sink into the ice. On the other hand larger
stones intercept the heat.

On most glaciers may be seen large stones rest-
ing on pillars of ice. These are the so-called Ice
tables. If the stone be wide and flat, the pillar may
reach a considerable height, for the ice immediately
under it, being protected from the rays of the sun,
melts less rapidly. The tables are rarely horizontal,
but lean to the south, that side being more exposed
to the sun. Small stones and sand, on the contrary,
absorb the heat and melt the snow beneath them,
unless indeed there is a sufficient thickness of sand,
in which case they intercept the heat and form
cones, sometimes ten or even twenty feet in height.

Medial moraines in the same way tend to check

126

SCENERY OF SWITZERLAND.

the melting. That on the Aar glacier rises 20, 40,
and even 60 metres above the general surface, and
from the summit of the Sidelhorn it gives the im-
pression of a wide black wall separating two white
rivers. In Greenland such ice-walls have been known
to attain a height of 125 metres.

We can hardly have a better introduction to
the study of glaciers than a visit to the Rhone
glacier. The upper part, which is not shown
in the figure, is a magnificent and comparatively
smooth ice-field. Then comes a sharp descent, where
in a river we should have a cascade or series of
cascades, and where the ice breaks into a series of
solid waves. The crests gradually melt, and as dust
and stones collect in the hollows, and the centre of
the glacier moves more rapidly than the sides, we
have a succession of dirt bands which curve across
the glacier.

Below the fall, the bed of the glacier becomes
again comparatively flat; the glacier is squeezed out
so as to become considerably wider, and as the ice
cannot expand it splits into a number of diverging
crevasses. This was much more marked when I
first visited the glacier in 1861, and when it was
much larger than at present.

If we start from the hotel, after crossing the river,

SNOW AND ICE.

127

at a very short distance we come to a bank ot loose
sand and stones, some angular, some rounded, which
curves across the valley, except where it has been
washed away by the river. This is the moraine of
1820, and shows the line at which the glacier stood
for some years. The Swiss glaciers generally in-
creased till about 1820, then diminished till about
1830, increasing again till about i860, since which
they have retreated considerably. The moraine of
1856, in the case of the Rhone glacier, forms a
well-marked ridge some distance within that of
1820.

From that ridge to the foot of the glacier, the
valley is occupied by sand and stones in irregular
heaps, some of them smoothed and ground by the
glacier. This is especially the case with the larger
stones, which show a marked difference on their two
sides, that turned towards the glacier being smooth,
while the lee side is rough and abrupt. Many of
the stones were evidently pushed by the glacier along
the valley, and have left a furrow behind them. The
Rhone wanders more or less over the flat bottom of
the valley, and spreads out the material which has
been brought down by the glacier.

Here and there on the glacial deposits lie blocks
with fresh angles, totally different in appearance from

128

SCENERY OF SWITZERLAND.

the rounded blocks borne by the glacier. These
have been brought down by avalanches.

Near the glacier are two other small moraines,
the outer one that of 1885, the inner of 1893. We
know that these moraines were deposited by the
glacier, and no one who has seen them can doubt
that those farther and farther down the valley have
had a similar origin.

The Rhone flows from the foot of the glacier in
various and varying streams, but especially at one
place near the centre of the face of the glacier,
where there is a beautiful blue arch, about 25 metres
in height.

In 1874 careful measurements were commenced
by the Swiss Alpine Club. At first lines of stones
were placed annually at the foot of the glacier, but
the river washed them away so much that the present
limits are laid down annually on a plan. It is found
that just as the glacier advances when we have a
succession of cold and 'snowy years, and diminishes
when there have been hot and dry periods; so in
each year, even when the glacier is on the whole re-
treating, it advances in two or three of the winter
months. Amongst other means of studying the
glacier the Commission have placed lines of stones
across it at some distances above the fall. One of

SNOW AND ICE.

129

these lines was arranged in 1874, the stones painted
yellow, and their position carefully marked. When
they came to the fall they disappeared for four
years, after which some of them again emerged at
the surface, and some of the central ones have
reached the lower end of the glacier, which has re-
treated some yards from the spot at which they were
deposited.

As in many of the most accessible glaciers, a
gallery has been cut into the ice, and is well worth
a visit.

The exquisite curves into which the ice is melted
by the eddying currents of air are very lovely. Again,
one can easily trace the glacier grains especially if a
little ink or other coloured fluid is rubbed over the
surface of the ice, when it runs down between the
grains, marking them out with dark lines. Each
grain, moreover, shows very fine lines of crystallisa-
tion, which are parallel in each grain, but differ in
different grains. The chief attraction, however, is
naturally the splendid blue colour of the ice, and the
lovely pink complementary tints of the reflections from
the surface.

Scenery of Switzerland. /.

130

SCENERY OF SWITZERLAND.

CHAPTER V.

ON THE FORMER EXTENSION OF GLACIERS.

Above me arc the Alps
The palaces of nature, whose vast walls
Have pinnacled in clouds their snowy scalps,

And throned Eternity in icy Halls
Of cold sublimity, where forms and falls
The avalanche — the thunderbolt of snow!

All that expands the spirit, yet appals,

Gather around these summits as to show
How Earth may pierce to Heaven, yet leave
vain man below.

Childe Harold’s Pilgrimage , Byron, hi. 62.

The present scenery of Switzerland has been
much influenced by the former extension of glaciers,
and the fertility of the country is greatly enhanced
by the materials which they have brought down from
the mountains and spread over the low country.
Several of the lakes, moreover, which add so much
to its beauty, owe their origin to ancient moraines.

The existence of a glacial period and the great
former extension of the Swiss glaciers is proved by
four lines of evidence, namely: — •

1. Moraines and fluvio-glacial deposits.

THE FORMER EXTENSION OF GLACIERS.

13 I

2. Erratic blocks.

3. Polished and striated surfaces.

4. Animal and vegetable remains belonging to
northern species.

Fig. 31. — View of the Grimsel.

1 3 2

SCENERY OF SWITZERLAND.

Fig, 32. — Scratched Pebble from the moraine at Zurich.

THE FORMER EXTENSION OF GLACIERS.

133

Glacial Deposits.

Glacial deposits may be classed under two
heads: —

1. Moraines.

2. Glacial deposits which have been rearranged
by water and may be termed fluvio-glacial.

Moraines are characterised by the presence of
polished and striated pebbles, intermixed with more
or less angular fragments, often coming from a great
distance and yet not rolled, irregularly deposited in
sand and mud, which, however, is not stratified.

Fluvio-glacial deposits are composed of the same
materials, but more or less rolled, and rearranged by
water, like river gravels. They are glacial deposits
caught up and carried to a greater or less distance
by water.

These two deposits are in intimate relation; they
agree in their composition, and differ only as regards
stratification. The fluvio-glacial beds, as we come
nearer and nearer to their source, are composed of
larger and more angular pebbles, while the stratifica-
tion becomes less and less regular, so that they ap-
proximate more and more to the character of true

moraine.

134

SCENERY OF SWITZERLAND.

The surface of a true glacial deposit is irregular,
and presents a succession of hills and valleys, often
more or less concentric in outline, and enclosing a
central depression {the site of the glacier itself), so
that it forms a sort of amphitheatre. See for in-
stance Fig. 33. The Wettingen Feld in the valley
of the Limmat is the cone of fluvio-glacial deposits
from the ancient moraine of Killwangen.

As glaciers often retreat and then advance again

TT/WVW/j !■

Fig. 33. — Glacial Deposits. I), site of ancient glacier ; Z, moraine ;
z, fluvio-glacial deposits.

the cone of transition in many cases presents alterna-
tions of true morainic and fluvio-glacial strata.

When the glacier retreated, the water occupied
the central depression between the ice and the
moraine, forming a lake. In most cases, however,
it cut by degrees through the moraine, and drained
the lake. The streams then wandered over the old
glacier bed. That the lake naturally overflowed at
the lowest point of the moraine, explains why the
outflow is often not in the centre of the valley, and
occasionally at some distance from the end of the

THE FORMER EXTENSION OF GLACIERS. 135

lake, as for instance, at the Lake of Hallwyl (Fig.
35 >

Far down the valleys we find moraines, exactly
similar in character to those still being formed along
the sides and in front of existing glaciers, and re-
peated again and again, indicating that glaciers
must once have extended far beyond their present
areas.

The Rhone glacier occupied the Valais, in which

Fig. 'id. — Section across the Vallejo of the Aar above Coblenz. Scale,
length 1=100,000 ; height 1=25,000. z, Lower alluvial terrace; y, upper
alluvium covered by moraines and Loess; a', alluvium of the upper pla-
teaux, covered by Loess ; Jurassic strata m situ.

are several ancient moraines; it filled the whole basin
of the Lake of Geneva; and the high terrace of St.
Paul above Evian is a moraine, due to the confluence
of the ancient glaciers of the Rhone and Dranse; so
is also the promontory of Yvoire. Still further down
the valley glacial deposits are found along the Rhone
as far as, and even beyond Lyons,* and down the
Aar to Waldshut.

* Falsan and Chantre, Les Anciens Glaciers du Bassin du
Rhone. 1880.

Fig. 35.— Map of the country between Lucerne and Aarau.

THE FORMER EXTENSION OF GLACIERS.

137

Fig. 34 represents river terraces and glacial de-
posits in the valley of the Aar, a short distance
above Coblenz.

Passing from the Aar eastwards, in the district
of the Wigger, there are important moraines round
the Lake of Wauwyl, which was itself the site of
a Lake Village carefully studied by Col. Suter, but
is now drained.

In the valley of the Suhr is an important ter-
minal moraine at Stafelbach, another at Triengen,
while a third encircles and has given origin to the
Lake of Sempach.

In the valley of the Winan there is a terminal
moraine at Zezwil and another just above Munster.

In the valley of the Aa, are three groups; firstly,
one near Schafisheim. Secondly, at the north end
of the Lake of Hallwyl are several moraines (Fig. 35);
thirdly, between Schafisheim and Egliswyl are three
moraines, the inner one encircling a moss, marked
Todtenmoos on the map, through which runs the
river Aa. Near Nieder Hallwyl is another semicircular
moraine enclosing an area of low ground and the
end of the lake. It extends along the hill on both
sides of the water. The moraines are in parts roughly
stratified, and fall away from the lake, having origin-
ally sloped no doubt from the great dome of the

138

SCENERY OF SWITZERLAND.

glacier. A third group encircles the lower end of
the Lake of Baldegger.

In the valley of the Reuss is perhaps the finest
group of all, consisting of five ridges forming an
amphitheatre round the little town of Mellingen. The
Heiterberg, between the Reuss and the Limmat, is
also encircled by one, which reaches a height of no
less than 100 metres.

In the valley of the Limmat there is a fine
terminal moraine at Killwangen, another below
Schlieren, a third at Zurich, and a fourth forms the
bank which crosses the Lake at Rapperschwyl. These
terminal moraines are connected by lateral moraines
running along the sides of the hills. They do not
mark the greatest extension of the glaciers, but in-
dicate places where the glaciers made a stand during
their final retreat.

The moraines on the south of the Alps are even
more astonishing. Probably from the steeper slope,
and more rapid melting under a southern sun, .the
ends of the glaciers do not appear to have moved
so frequently. Hence the terminal moraines are
more concentrated, grander, and higher. They form
immense amphitheatres terminating in ridges several
hundred feet high, and no one seeing them for the
first time would for a moment guess their true nature.

THE FORMER EXTENSION OF GLACIERS.

139

The blueness of the sky, moreover, the brilliancy of
colouring, the variety and richness of the vegetation,
give the moraine scenery of Italy an exquisite beauty
with which the north can scarcely vie. Each great
valley opening on the plain of Lombardy has its own
moraine. At the lower end of the Lago Maggiore
at Sesto-Calende are three enormous concentric
moraines.* Those of the Lake of Garda are perhaps
the largest. They form a series of concentric hills,
and attain a height of 300 metres, but those at
Ivrea, at the opening of the Val d’ Aosta, due to the
great glacier proceeding from the south flanks of the
Mont Blanc range, are the highest and most impos-
ing. They form an amphitheatre round Ivrea. That
on the east, known as the “Serra,” runs in nearly a
straight line from Andrate to Cavaglio, is twenty
miles long, and has a height above the valley of
500 metres. The summit line is very uniform. On
the outer or eastern side of the great moraine are
several other minor ridges. At the right a similar,
but less elevated moraine, stretches from Brosso to
Strambinello, but it is not so conspicuous, as it rests
against the side of the mountain. From Strambinello
to Cavaglio it forms a great semicircle which once

* Martins and Gastaldi, “Essai sur les terrains sup. de la
Vallee du Po,” Bull. Soc. Ge'ol. de France. 1850.

SCENERY OF SWITZERLAND.

probably enclosed a lake, now represented by the
Lago di Viverone, Lago di Candia, and some smaller
pools. It is nearly bisected by the Dora Baltea. In
fact, it is characteristic of the Italian valleys that the
surface is comparatively low where the valley de-
bouches into the plain, and then gradually rises to-
wards the Po, forming an amphitheatre whose en-
circling wall is the outer moraine*

At several places on the south flank of the Alps,
morainic masses are more or less intercalated with
younger marine deposits, closely resembling the sub-
marine moraines of the Polar regions, and the
Boulder Clay of England and Scotland.

The older moraines are, moreover, less abrupt,
and the slopes are more gentle.

Erratic Blocks.

The second class of evidence proving the former
extension of glaciers is that presented by erratic
blocks, which are often of great size, unrounded, and
which have come from a great distance. Many of
these are so remarkable that they have struck the
imagination of the peasantry, have been attributed
to superhuman agency, and have received special
names, such as the “Pierres de Niton” in the lake
* Penck, Vergletscherung der Deutschen Atyen.

THE FORMER EXTENSION OF GLACIERS. I4I

near Geneva, so called from a tradition that in
Roman times sacrifices were offered upon them to
Neptune. The “Pierre de Crans” near Nyon, is 73
feet long and 20 high.

The “Pierre a Bot,” near Neuchatel, at a height
of 2200 feet, is 62 feet in length, 48 in breadth, and
40 feet high. It is of Protogine, and probably came
from the Mont Blanc.

Other celebrated erratic blocks are the “Plough-
stone,” which rises 60 feet above the ground be-
tween Erlenbach and Wetzweil, and contains over
72,000 cubic feet of stone; the Bloc du Tresor near
Orsi^res with a cubic content of 100,000 feet; the
Monster block at Montet, near Devent, 160,000; and
the largest of all is, I believe, a mass of Serpentine
on the Monte Moro, near the Mattmark See, which
measures 240,000 cubic feet. These enormous
blocks are of course exceptional, but smaller ones
are innumerable. In some localities are immense
groups — for instance on the hill of Montet, near
Devent, at Orsiires in the valley of the Dranse
D’Entremont above Martigny, at Arpille on the north
side of the valley of the Rhone opposite Martigny,
and, still further away from the mountains, the entire
south slope of the Jura is strewn with Granite blocks.
“Between Moliers, Travers, and Fleurier,” says De

I 4 2

SCENERY OF SWITZERLAND.

Luc, “there are as many blocks of primitive rock as
if one was in the high Alps.”*

One of the most remarkable groups is at Monthey,
overlooking the valley of the Rhone below St. Mau-
rice. We have here, says Forbes, “a belt or band
of blocks — poised, as it were, on a mountain side, it
may be five hundred feet above the alluvial flat
through which the Rhone winds below. This belt
has no great vertical height, but extends for miles —
yes, for miles — along the mountain side, composed
of blocks of Granite of thirty, forty, fifty, and sixty
feet in the side, not a few, but by hundreds, fan-
tastically balanced on the angles of one another, their
grey weather-beaten tops standing out in prominent
relief from the verdant slopes of secondary formation
on which they rest. For three or four miles there is
a path, preserving nearly the same level, leading
amidst the gnarled stems of ancient chestnut trees
which struggle round and among the pile of blocks,
which leaves them barely room to grow: so that
numberless combinations of wood and rock are
formed where a landscape-painter might spend days
in study and enjoyment.”**

As already mentioned, these blocks have come

* Agassiz, Essai sur les Glaciers.

** Forbes, Travels through the Alps of Savoy.

THE FORMER EXTENSION OF GLACIERS.

from a great distance. No similar rock occurs in the
neighbourhood, and it is often possible to determine
the locality from which they have been derived.

For instance, near the Katzensee is a block con-
sisting of a peculiar variety of Granite only known to
occur at Ponteljes-Tobel above Trons in the valley of
the Rhine. Many blocks of the same rock occur on
the right bank of the Lake of Zorich, and they can
be followed all the way to their source. Not one
occurs to the left of the lake. This could hardly be
the case on any other theory than that of transport
by a glacier. Again, the “Ploughstone” already men-
tioned agrees with the fine-grained Melaphyre of the
Gandstock in the middle of the Canton of Glarus.

The block of Steinhof near Soleure, which
measures 65,000 feet, is probably from the Val de
Bagnes.

The Pierre a Bot, as already mentioned, is of
Protogine, and has come from the St. Bernard.

It is probable that the ancient glaciers moved
more rapidly than their comparatively diminutive de-
scendants of the present day; but at the existing rate
Of movement the Pierre a Bot would have taken
1000 years to travel from its original home on the
chain of Mont Blanc to its present site near Neu-
chatel; Whymper calculated that the blocks at Ivrea

i 4 4

SCENERY OF SWITZERLAND.

would have taken a similar period, the Granite
blocks of Seeberg would have spent 2000 years and
according to Falsan those at Lyons some 4000 years
on their long journey.

It is evident that these blocks cannot have been
brought by water, both on account of the immense
velocity which would have been required to transport
such enormous weights, and because, amongst other
reasons, their angles are as a rule sharp and unrounded.

Their presence is often attributed to super-
natural agency, and many legends grew up round
them. Favre* records a remark made to him by
a peasant with reference to a great block of Pro-
togine near Sapey. “‘Jamais,’ disait-ils, ‘on a vu une
si belle: elle est tout entiere, rien de casse. Et puis,
elle est si tranquille. On ne sait pas si les pierres
grandissent; mais, il y a 15 ans, je pouvais monter
dessus, a present je ne sais comment cela se fait,
mais je n’y puis grimper.’”

Playfair, in 1802, appears to have been the first
to compare these erratics with moraines, and to sug-
gest that they w r ere transported by glaciers.

“For the moving of the large masses of rock,”
he says,** “the most powerful agents without doubt

* Reck. Ge'ol., vol. I.

** Illustrations of the Huttonian Theory, vol. I.

THE FORMER EXTENSION OF GLACIERS.

145

which nature employs are the glaciers, those lakes
or rivers of ice which are formed in the highest
valleys of the Alps, and other mountains of the first
order. These great masses are in perpetual motion,
together with the innumerable fragments of rock
with which they are loaded. These fragments they
gradually transport to their utmost boundaries, where
a formidable wall ascertains the magnitude, and
attests the force, of the great engine by which it
was erected.” The immense quantity and size of the
rocks thus transported have been remarked with
astonishment by every observer. Perraudin, a Chamois
hunter of the Val de Bagnes, subsequently but inde-
pendently made the same suggestion to Charpentier.
It also occurred to, and was proposed in more detail
by Venetz, and at length in 1829 worked out by
Charpentier with masterly ability. Agassiz compared
the Swiss phenomena with those presented in the
north of Europe, and showed that in both cases the
country was covered by a sea of ice, from which the
highest summits alone emerged.

Charpentier , * and subsequently Guyot,** traced
the course of many erratic blocks, and pointed out
that as we proceed from the place of origin they

* Essai sur les Glaciers.

** Bull. Soc. Sci. Nat. Neuchdtel , vol. I.

Scenery of Switzerland. I. I O

146

SCENERY OF SWITZERLAND.

spread as it were in a fan, and that those from one
district do not overlap those from another, as would
be the case if they had been distributed by rivers or
icebergs: for instance, those of the West Jura come
from Mont Blanc and from the Valais, those of the
Bernese Jura from the Bernese Oberland, and those
of Argovie from the eastern cantons and the Rhine.*
Not only are the blocks from each drainage area
kept separate, but even, as a rule, those from the two
sides of the same valley. I say as a rule, because
in some few cases the glaciers appear to have varied
in relative dimensions, one encroaching for a time on
another, and in its turn being driven back. This
however only applies to some few exceptional areas,
as for instance between the glaciers of the Linth and
the Reuss.

Again, the erratic blocks are specially numerous
on the summits and slopes of hills, much more than
in valleys: they are not sorted in sizes, but even the
largest are found perhaps 50, or even 100, miles
from their original site. The smaller blocks are
often polished and striated, like those on existing
glaciers.

For these and other reasons there can be no

Agassiz, Etudes sur les Glaciers .

THE FORMER EXTENSION OF GLACIERS. 1 47

doubt that they have been carried by glaciers to their
present position.

These great blocks, however, imposing as they
are, are yet as nothing to the mass of gravel, sand,
and mud brought down by the glaciers, carried over
intervening ridges and across lakes, and spread over
the whole of Switzerland.

The erratic blocks are unfortunately rapidly dis-
appearing, as they are much in demand for building
and other purposes. Some of the most remarkable
have, however, happily been secured, and will be pre-
served by the Swiss Scientific Societies.

Considering the immense magnitude of the mo-
raines and the enormous number of erratic blocks, it
is evident that the glacial period must have been of
very long duration.

Polished and Striated Surfaces. — Roches
Moutonnees.

A third class of evidence is that furnished by
polished and scratched rock surfaces, which of course
are best preserved when the material is hardest.
The rocks are sometimes polished like a looking-
glass. Such surfaces occur under and round exist-
ing glaciers, where there can be no doubt that they
are the work of the ice, or rather of the stones con-

148

SCENERY OF SWITZERLAND.

tained in it. Fig. 31 is a photograph of the Hospice
of the Grimsel, showing a remarkable case of such
glaciated rocks. Similar surfaces occur, however, far
away from the present glaciers and even in countries
where none exist. The grey rounded bosses (Fig. 31)
were termed by De Saussure “Roches Moutonnees,”
from their frizzled surface. The term has been
generally adopted, mainly perhaps because at a dis-
tance they look not unlike sheep’s backs. Smooth
rock surfaces may often be seen at the sides of val-

Fig. 36. — Diagram of Crag and Tail.

leys, sometimes at a great height — many hundred or
even some thousands of feet above the present river,
and far away from the present glaciers, as, for in-
stance, on the slopes of the Jura. They are specially
well developed where from a turn in the valley, or
any other cause, the ice met with most resistance.
The rocks at Martigny are a very fine example.

They do not, however, generally rise to the upper-
most ridges, which have therefore (Fig. 37) quite a
different character.

De Saussure first noticed the prevalence in the

THE FORMER EXTENSION OF GLACIERS.

149

Alps of smooth, and even polished rock surfaces, but
he did not suggest any explanation. Charpentier
pointed out that they were due to the action of
glaciers. Running water also smooths rocks, but it
is almost always easy to distinguish the action of
water from that of ice. In the first place, the
“Roches Moutonnees” are generally marked by striae,
running in the direction of the valley, and due to

Fig. 37. — View of the Brunberghbrner and the Juchlistock, near
the Grimsel, showing the upper limit of glacial action.

small stones contained in the ice, and frozen earth.
Again, water acts most energetically in the hollows,
ice especially on any projecting surface, so that in
water-worn surfaces the curves are concave, while on
“roches moutonnees” they are convex. The action
of water is also much more irregular than that due
to ice.

De Saussure was also long ago struck by the fact

I 5° SCENERY OF SWITZERLAND.

that at Chamouni, in the valley of the Aar, and else-
where, the higher rocks were angular and pointed,
while the sides of the valley below were rounded
and smooth, but he did not suggest any explanation.
Hugi observed the same fact, and attributed it to a
difference in the character of the rocks.” Desor,*
however, in 1841 ascended the Juchliberg, where the
contrast is well marked, and satisfied himself that
the Gianite was absolutely the same. He observed,
moreover, that on the smooth Granite, especially on
the upper part, were many blocks of Gneiss, brought
from the Mieselen and the Ewigschneehorn. These
blocks could only have been brought by glaciers, and
he concluded, therefore, that the smooth polished sur-
faces were due to the action of the glacier, and that
the rough, angular upper parts were those which had
stood above the level of the ice.

Such polished surfaces are by no means confined
to the Alpine valleys. Where suitable rocks occur,
they are found throughout the central plain and on
the Jura, when they are often very well developed,
and known locally as Laves. The upper level of the
rounded rocks falls with the valley.

On the shores of Norway and Sweden such
glaciated surfaces can even be traced under the sea,

* Desor, Gebirgsbau.

THE FORMER EXTENSION OF GLACIERS. I 5 I

especially when the water is free from sand. The
scratches follow the general direction of the valley,
the polished surfaces are on the weather side, and
the lee side is the most abrupt, as in Fig. 36. A
good example of such smoothed rocks may be seen
just in front of the great Hotel at the Maloja.

Giants’ Caldrons.

Giants’ caldrons are sometimes assumed to be
evidence of ancient glacier action. Those at Lucerne
doubtless are so, but in other cases similar hollows
have been produced by river action.

Evidence derived from the Flora and Fauna.

Another class of evidence is that derived from
botany and zoology. Many of the plants now occupy-
ing the Swiss mountains are indigenous to the Arctic
regions. They could not under existing circum-
stances cross the intervening plains, but must have
occupied them when the climate was colder than it
is now, and been driven up into the mountains, like
the Marmot and the Chamois, as the temperature
rose. The Arctic Willows, the Larch, and Arolla pine,
for instance, are Siberian species, and do not occur
in Germany.

152

SCENERY OF SWITZERLAND.

Here and there also in the drift and the peat-
mosses of the lowlands remains have been found of
Alpine and Arctic species — the Arolla pine, dwarf
birch (Betula nana), Arctic willows (Salix polaris,
Salix retusa, and Salix reticulata), Dryas octopetela,
Polygonum viviparum, etc.

Moreover, we find living colonies of high Alpine
species, the seeds of which can scarcely have been
carried by wind, on elevated summits in the lower
districts, and in the marshes behind ancient moraines.
They cannot have been brought by water, because
they occur in some districts not watered by Alpine
streams. On the Uetliberg Prof. Heer found two
plants which especially characterise moraines — the
Alpine toad flax (Linaria Alpina), and a willow-herb
(Epilobium Fleischeri). An Alpine fern (Asplenium
septentrionale) which is said to be found nowhere
else in the Canton of Ziirich, occurs on the Plough-
stone of Erlenbach. There are two Swiss species of
Rhododendron — one with the under surface of the
leaves rusty (R. ferrugineum), the other with fringed
leaves (R. hirsutum). The latter species prefers a
limestone soil and lower regions, so that we should
expect to find it prevalent on the Jura. Yet the
rusty-leaved species alone occurs there, having prob-
ably been brought by the ancient glacier from the

THE FORMER EXTENSION OF GLACIERS.

153

Crystalline mountains of the Simplon and St. Bernard,
where it is very abundant.*

The animal kingdom also affords us similar evi-
dence. We find living colonies of Alpine and Arctic
animals, especially Insects and Molluscs, on the sum-
mits of isolated mountains and in the marshes be-
hind moraines, in association with Alpine plants and
erratic blocks. Moreover, just as land animals have
retired up the mountains, so have aquatic species
been driven into deeper and colder waters — Nephrops
norvegicus, for instance, into the depths of the sea
at Quarnero, several Arctic animals into the deep
waters of the Swedish lakes Wenern and Wettern.
In the glacial deposits remains of various Arctic
species have been met with. In the gravel-beds
near Maidenhead, Charles Kingsley and I found a
skull of the Musk Sheep, and remains of the same
species, though rare, have since been met with in
other parts of Europe. With the Musk Sheep, the
Urus, the Aurochs, the Wild Horse, the Mammoth,
Hairy Rhinoceros, Reindeer, Elk, the Giant Stag or
Irish Elk, Glutton, Ibex, Chamois, Cave Hyaena, Cave
Bear, Polar Fox, Lemming, Ptarmigan, Marmot,
Snowy Owl, etc., have been also found in glacial

Heer, Primaeval World of Switzerland, vol. II.

154

SCENERY OF SWITZERLAND.

deposits, though fossil remains are rare in the Swiss
deposits of this age.

It would be out of place in the present volume
to enter into the consideration of the causes which
probably led to the existence of the glacial period,
or to its probable date. I have in my " Prehistoric
Times discussed this question, to which I may refer
those who wish to go further into the subject, and I
will here only say that I see no sufficient reason to
change the opinion (though doubts have recently
been thrown on it by Sir H. Howorth and others),
that it was mainly due to astronomical causes, and
reached its maximum from 50 to 100,000 years ago.

If this explanation be correct it follows that
periods of cold and warmth must have followed one
another more than once, at intervals of 21,000 years.
And in accordance with this we find, as Morlot long
ago pointed out, that the glaciers have advanced and
retreated more than once.

Beds indicating warmer conditions are interposed
between glacial deposits, and the Swiss and South
German geologists believe that there were three
periods of cold with milder intervals. In Scotland
James Geikie and others have brought forward evi-
dence of more numerous oscillations.*

* The Great Ice Age.

THE FORMER EXTENSION OF GLACIERS. 1 55

Morlot was primarily led to this conclusion by
his observations in the valley of the Dranse, south of
Thonon on the Lake of Geneva, which I had the
pleasure of visiting under his guidance. In this gorge
between two well-marked glacial deposits is a deposit
indicating a milder climate.

Again, at several places in the Canton of Zurich
are beds of lignite, sufficiently thick to have been
worked for fuel. They are intercalated between
glacial deposits; they indicate a luxuriant vegetation
and consequently a mild climate; they contain, more-
over, remains of animals, such as the Hippopotamus,
which could not support great cold. This can only
be accounted for, I think, by assuming that these
groups of animals occupied the country alternately.

Moraines which have been long exposed to the
atmosphere become gradually modified at the sur-
face. The pebbles are much weathered and some-
times quite disintegrated, even those of Granite crum-
bling into a sort of clay while retaining their original
form. The layer affected may have a thickness of
one to two feet or even more. This weathered crust
often assumes a reddish colour, whence it is called by
Italian geologists “Ferretto.”

Where an old moraine has after a long interval
been covered by a later one, the Ferretto enables us

1 56 SCENERY OF SWITZERLAND.

to distinguish between the two. It is in fact a strong
confirmation of the existence of inter-glacial periods,
during which the glaciers retreated, and a more
genial climate prevailed. At Ivrea, for instance, the
presence of Ferretto shows that the gigantic moraine
known as the Serra was not formed during one long
continuous glaciation. r lhe moraines which are coated
with Ferretto occupy as a rule the outer side of the
morainic amphitheatre, and are covered on their
inner edges by the later and inner moraines. Lignite
beds also occur on the south of the Alps* One of
the places where an inter-glacial period is most clearly
shown is in the valley of the Inn. At Hottingen,
close to Innsbruck, is a great fluvio-glacial deposit,
reposing on a ground moraine at a height of 1300
meties above the bottom of the valley, and capped
to a height of 1900 metres by another. In these
fluvio-glacial beds forty-one species of plants have
been found and studied by M. Wettstein. Of these
twenty-nine now live in the immediate neighbourhood,
six in the Tyrol, but at a lower level, six further
south, and four have not been determined. Here
then we have evidence that the valley of the Inn
was (firstly) filled by a glacier to the height of 1300

* Riitimcyer, Ober Pliocene tend Eisperiode auf beiden
Seiten der Alpen.

THE FORMER EXTENSION OF GLACIERS.

157

metres, (secondly) that then followed a period with
a climate somewhat milder than the present, suc-
ceeded (thirdly) by another glacial period, during
which the valley was again filled by ice to a depth
of 1900 metres.*

The first Age is represented by ground moraine,
and by “Deckenschotter”; a diluvial gravel, curiously
characterised by the presence of rounded hollows.
These were formerly occupied by pebbles, which
have been dissolved and washed away through the
hard but permeable matrix.

With the exception of one or two heights, as for
instance the Napf, there is, on the whole of the
Central Plain between the Jura and the Rhine, no
considerable area where traces of former glacial
action are not to be met with. They attain in places
a great thickness, sometimes even more than 400
metres.

It seems at first therefore remarkable that no
terminal moraines are known which can be referred
to this period. But it must be remembered that the
whole country was covered by ice, with the exception
of the very highest parts. Hence no doubt, as is
the case in Greenland now, the surface of the ice
was very free from debris, and hence, perhaps, the

* Penck, Vergletscherung der Deutschen Al^pen.

158

SCENERY OF SWITZERLAND.

peripheral glacial deposits are only represented by
ground moraine.

The second Ice Age is represented by the mo-
raines high up on the hills overlooking the valleys;
and the third by moraines which form more or less
complete ridges curving across the valleys, and along
the slopes. It is possible that the glaciers may in
some cases have been pushed forwards again over
the inner moraines. At Hallwyl, for instance, the
moraine immediately encircling the lake is very flat,
which Dr. Mtlhlberg thinks may be thus accounted for.

Limits of the Ancient Glaciers.

The evidence seems then conclusive that the
glaciers were once far larger than at present, and the
facts already summarised give some indication of
the extent. Beginning with the Rhone Glacier, the
former upper limit of the ice at Oberwald was 2766
metres, or 1400 above the river;* at Viesch it was
2700, or 1700 above the river; at Leuk 2100, or
1470 above the river; at Martigny 2080, or 1620;
at Geneva 1300, or 950 metres above the Lake.**
On the slopes of the Jura it rises highest at Chasseron,
north-west of Neuchatel, opposite the valley of the

* Falsan and Chantre, Anc. Glaciers du V. du Rhone, vol. II,

** Favre, Description Geol. du Cmton de Geneve, vol. j.

THE FORMER EXTENSION OF GLACIERS.

159

Rhone, where it attains an elevation of over 1350
metres, or 977 above the lake, descending gradually
to the plain on one side at Soleure, on the other at
Gex. At Neuchatel, the erratic blocks form a band
about 800 feet above the lake. Above and below
that line they rapidly diminish in number.

The Rhone glacier then, at the period of its
greatest extension,* not only occupied the whole
Valais and the Lake of Geneva, but rising on the
Jura to a height of 1350 metres, crossed the Vuache,
descended into the present Rhone valley, sweeping
round by Bourg, Trevoux, Lyons, and Vienne on one
side, sent a wing beyond Pontarlier as far as Salins
and Ornans, and extended down the valley of the
Aar as far as Waldshut, almost meeting the western
extremity of the glacier of the Rhine.

The ancient glacier of the Rhine occupied the
Lake of Walen, the whole valley of the Thur as far
as Schaffhausen, the Klettgau, and almost to Walds-
hut, filled up the Lake of Constance, extending con-
siderably to the north down the Danube as far as
Sigmaringen, while for some distance its northern end
followed the present watershed between the regions of
the Rhine and the Danube.

Thus the two great glaciers of the Rhone and

* See Favre, Carte des Anciens Glaciers de la Suisse.

i6o

SCENERY OF SWITZERLAND.

the Rhine almost enclosed those of the Aar, the
Reuss, and the Lirnmat. That of the Aar extended
as far as Berne, where there is a very fine moraine.

The glacier of the Reuss extended to Aarau,
and down the Valley of the Aar to Coblenz. On
the east it filled the Lakes of Egeri and Zug, ex-
tended along the Albis to the Uetliberg, and to
Schlieren on the Lirnmat, following the valley down
to Coblenz.

The glacier of the Lirnmat was bounded on the
west by that of the Reuss; on the east from Wesen
on the Lake of Walen, to the Rhine at Eglisau, fol-
lowing the valley to Coblenz, where therefore these
four great glaciers met.

The glaciers of the Mont Blanc range not only
filled the Valley of Chamouni and the country to the
west as far as, and beyond, the Lake of Bourget,
but flowed over to the east and joined that of the
Rhone.

In fact a sea of ice covered the whole country,
with the exception of some mountain tops, from
Lyons to Basle, along the Rhine and the Lake of
Constance across Bavaria, extending to Munich, and
beyond Salzburg.

The extension of the glaciers does not however
necessarily imply any very extreme climate.

THE FORMER EXTENSION OF GLACIERS. 1 6 I

Paradoxical as it may appear, glaciers require
heat as well as cold: heat to create the vapour,
which again condenses as snow. A succession of
damp summers would do more to enlarge the glaciers
than a series of cold seasons. Leblanc* estimated
that the glacial period need not have had an average
temperature of more than 7 degrees centigrade below
the present, and other great authorities consider that
at anyrate a fall of even 5 0 would suffice.

The temperature decreases 1 0 for about every
188 metres. A fall of 5 0 would = 940 metres.
The present snow-line being 2700 metres, would de-
scend to 1760 metres, and the lower limit of the
glaciers from 1 200 metres to 360 or somewhat below
Geneva, the level of which is 375. It would indeed
be even lower, because the greater the snow-field, the
further the glacier descends.

We have no evidence of the existence of Man in
pre-glacial times, and whether he inhabited Switzer-
land during the inter-glacial period is still uncertain.
Rutimeyer has described certain pieces of wood be-
longing to that period, which have been cut by some
sharp instrument, and which are so arranged as to
form a sort of basket-work. They certainly appear

* Bull . Soc. Geol . France . 1843 .

Scenery of Switzerland. I. I I

162

SCENERY OF SWITZERLAND.

to be due to human workmanship, but the evidence
is not altogether conclusive.

It has happened no doubt to many of us to stand
on some mountain-top when the surrounding summits
have been covered with snow, and the intervening
valleys have been filled with a thick white mist,
which, especially in the early morning light, can
hardly be distinguished from snow. In such a case,
we have before us a scene closely resembling that
which the country must have presented while it was
enveloped by the ice of the glacial period.

The geologists of Bavaria have brought forward
strong evidence for the belief that in Bavaria and
Swabia there were three periods of great extension
of the glaciers with intervals of a milder climate;
and Dr. Du Pasquier, who has especially studied the
fluvio-glacial deposits of Switzerland, considers that
they confirm this view.

The first cold period is, he considers, represented
by the so-called “Deckenschotter,” of which perhaps
the best known example is that on the summit of
the Uetliberg near Zurich, at a height of 400 metres
above the lake. It is a coarse gravel, more or less
cemented together, and in which many of the pebbles
have perished and disappeared, leaving rounded

THE FORMER EXTENSION OF GLACIERS. 1 63

cavities.* This deposit originally formed a more or
less continuous sheet, from 30 to 50 metres in thick-
ness, deposited by the water flowing from the melt-
ing glaciers, but has been to a great extent removed,
fragments only remaining here and there on the high
ground. It is remarkable that it contains no traces
of Julier or Puntaiglas Granite,** probably because
these rocks were still covered by the Crystalline
schists. The lateral Moraines of this period are un-
known, but the ground Moraines are sometimes well
developed. Under the Deckenschotter on the Uetli-
berg they attain a thickness of 2 to 20 metres.
They were probably for the most part destroyed by
the glaciers during the Second Ice Age.

The Second Ice Age is represented by gravel-beds,
still far above the present valleys, though at a lower
level, and by outer and upper moraines, for an in-
stance in the Zurich district those of Hongg, of the
Albis, etc. The terminal moraines of this period
were however probably beyond the boundaries of
Switzerland.

Th? Third Ice Age is indicated by the lower
terraces and the moraines in the valleys. In that
of Zurich, the Moraine of Killwangen was pro-

* This structure does not occur in the true Nagelfiue.

** Du Pasquier, Beitr. z. Geol . K. d. Schw L. XXXI.

1 1

SCENERY OF SWITZERLAND.

164

bably the outermost, while those of Zurich and
Rapperschwyl represented long periods of arrest
and standstill of the glaciers during their general
retreat.

In theory this explanation is clear and simple,
but it is not always easy to identify the beds. The
“Deckenschotter,” or upper and older bed, can in-
deed be generally recognised by the numerous
cavities, the “rotten” condition of many of the
pebbles, by its being much more frequently
cemented together, and in some districts by the
nature of the pebbles; in the Zurich Valley, for in-
stance, by the absence or great scarcity of Sernifite
and of the Alpine siliceous rocks, and by the fre-
quency of Hochgebirgskalk, which does not occur in
the Miocene Nagel flue;* but there are many glacial
deposits the exact age of which is very uncertain.

The following table gives the periods, the deposits,
and the great characteristic Mammalia, according to
Dr. Du Pasquier:** —

* Appeli, Beitr. z. Geol. K. d. Schw L. xxxiv.

** Beitr. z. Geol. K. d. Schw., L. xxxi. '

TABLE OF FLUVIO-GLACIAL DEPOSITS.

THE FORMER EXTENSION OF GLACIERS. I 65

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1 66

SCENERY OF SWITZERLAND.

The Glacial periods were in general, in Dr. Du
asquier’s opinion, so far as the central Swiss valleys
were concerned, periods of deposit, the inter-glacial,
periods of excavation.

VALLEYS.

167

CHAPTER VI.

VALLEYS.

Valleys and rivers are so closely associated with
one another, that we generally think of them as in-
separably connected; and indeed there are but few
valleys which have not been deepened and profoundly
modified by the action of water.

Nevertheless many valleys are “tectonic, that is
to say, they are due, or stand in a definite relation,
to geological structure; and there are some details of
valley modelling, which are independent of water
action, and which it may be convenient to consider
separately.

As already mentioned the plain of Lombardy is
a valley of subsidence, the lower limb, as it were, of
the great arch of the Alps. It has not been ex-
cavated by the Po; on the contrary, that river has
been for ages occupied in filling it up, and at Milan
a boring was sunk 162 metres without reaching the
bottom of the river deposits.*

* Penck, Morphologic tier Erde, vol. II.

i68

SCENERY OF SWITZERLAND.

The valley of the Rhine below Basle is also a line
of subsidence, and the two Crystalline regions of the
Black Forest and the Vosges were once continuous.

Valleys belong to several different classes, and in
Switzerland have received special names, such as
Vais, Combes, Cluses (Clausa, closed), Ruz, Cirques,
etc., which, however, do not cover all the different
kinds, and are not always used in the same sense.

In many cases valleys follow the “strike” or
direction of the strata, in which case they are termed,
as first suggested by De Saussure, longitudinal val-
leys; while in others they cut across the strata and
are known as transverse or cross valleys, or cluses.

Longitudinal valleys again, as Escher von der
Linth first pointed out, are of three distinct kinds.

Synclinal valleys (see ante, p. 69) occupy the
depressions of folded strata. Many of the Jura
valleys belong to this class. They are generally
broad.

Anticlinal valleys are those which arise when the
arch between two synclinals is broken, and the action
of water being thus facilitated, a valley is formed, as
for instance the Justithal (Fig. 1 26, vol.11. p. 164), which
opens on the Lake of Thun.

In both these classes the strata are the same on
the two sides of the valley. A third class of longi-

VALLEYS.

169

tudinal valleys is due to the outcrop of layers of
different hardness.

In such cases the strata on the two sides are
dissimilar; such valleys F

are known in Switzerland
as “Combes.”*

Suppose a fractured
anticlinal (A A' A", Fig. 38) e
has been lowered by
denudation to A C'A",
and is drained by a stream
running from C to E. If
the strata are of different
degrees of hardness, a
soft stratum BE B" be-

* In this country the word “Combe” is often used as syno-
nymous with “cirque.”

170 SCENERY OF SWITZERLAND.

tween two harder ones A and C will here and there
be brought to the surface.

In such a case, owing to the greater softness
of the stratum B, secondary streams will often cut
their way back as in Fig. 39, FF, thus forming
longitudinal valleys parallel to the ridge, the sides
being formed by the harder strata AC. Such valleys
(Fig. 40) are common in the Jura.

Sometimes there may be two or even three such
“Combes” along a main valley, as for instance

(Fig. 41) between Mont
Tendre and the valley
of the Orbe, where we
have four ridges of
harder strata, Urgo-
nian, Neocomian, Va-
langian, and finally
Portland rock enclos-
ing three combes due to the existence of softer layers.

It is obvious that in this case the transverse
valley DE (Fig. 39) is older than the longitudinal

valley FF.

A glance at any geological map of Switzerland
will show that many rivers run along the boundary,
that is at the outcrop, of strata.

The long lines of escarpment which stretch for

VALLEYS.

1 7 1

miles across country, and were long supposed to be
ancient coast lines, are now ascertained, mainly
by the researches of Whitaker, to be due to the
differential action of subaerial causes. The Chalk
escarpments in our own country and the great wall
of the Bernese Oberland are of this character.
That the longitudinal valleys owe their origin to
the same cause as the mountain chains, may safely
be inferred from the fact that they follow the same
direction. They are in fact negative mountain chains.

Transverse valleys cross the strata more or less
at right angles. They are generally narrow, and
often form deep gorges, more or less encumbered by
fallen rock, and the harder the rock the narrower the
valley.

Their character is greatly influenced by the

172

SCENERY OF SWITZERLAND.

nature of the strata, their inclination, and whether
the fall coincides with, or is in opposition to, that of
the beds.

Unless, however, the fall of the ground coincides
exactly with that of the strata, a river running along
a transverse valley will generally cross here and there
harder layers which give rise to cataracts or water-
falls.

When the strata are horizontal the action of
running water is comparatively slow. Steeply in-
clined or vertical strata on the other hand greatly
facilitate erosion. Not only does the force of gravity
take part in the labour, but the water sinks in more
easily, and both chemical and mechanical disintegra-
tion is thus much increased.

Hence it is that while cross valleys often drain
longitudinal valleys, the reverse seldom happens.
Cross valleys in fact dominate longitudinal valleys.

Another respect in which, so far as Switzerland
is concerned, the longitudinal differ from the trans-
verse valleys, is that the former run approximately
east to west, the latter north to south. This makes
a great difference in their general aspect. In the
transverse valleys not only do the two sides consist
of similar rocks, but both receive approximately the
same amount of light and sunshine, so that the

VALLEYS.

173

vegetation grows under more or less similar condi-
tions.

In the longitudinal valleys, on the contrary, not
only are the strata often different on the two sides,
but the northern side, which looks to the south, re-
ceives more sun, while the southern side is more in
shadow. The contrast is strongly shown in the
Valais itself, where the south side is green and well
wooded, the north, on the contrary, comparatively
dry and bare.

In some places, for instance in the valley of the
Rhone below Visp, the green lines of vegetation which
follow the “Bisses” or artificial water-courses are very
conspicuous.

On the Lake of Zurich, though the vegetation is
the same on both sides — woods and meadows and
vineyards — the distribution is quite different. Both
sides of the Lake are terraced, so that we have flat
zones and steep slopes. On the northeast side the
slopes get more sun, and hence the vines are planted
on them, while the meadows and woods are on the
terraces. On the west, however, the terraces get
more sun, and consequently the vines are on the
terraces and the meadows and woods on the slopes.

There is another class of valleys, namely, those
which are due to lines Of fracture or dislocation, and

*74

SCENERY OF SWITZERLAND.

which may be termed fault- valleys. They are, how-
ever, comparatively rare.

One and the same river may be of a very dif-
ferent character in different parts of its course. It
may run at one place in a longitudinal, at another
in a transverse valley. The Rhone for instance oc-
cupies a transverse valley from the glacier nearly to
Oberwald, a longitudinal valley from Oberwald to
Martigny, and a cross valley from Martigny to the
lake.

If we look at an ordinary map of Switzerland,
we can at first sight trace but little connection be-
tween the river courses and the mountain chains.
If, however, the map is coloured geologically, we see
at once that the strata run approximately from S.W.
to N.E. and that the rivers fall into two groups
running either in the same line or in one at right
angles to it.

The central mountains are mainly composed of
Gneiss, Granite, and Crystalline Schists; the line of
junction between these rocks and the Secondary and
Tertiary strata on the north, runs, speaking roughly,
from I Iyeres to Grenoble, and then by Albertville,
Sion, Chur, Innsbruck, Radstadt, and Hieflau, to-
wards Vienna. This line is followed (in some parts
of their course) by the Isere, the Rhone, the Reuss,

TuoyJT

Fig. 42.— Sketch Map of the Swiss Rivers.

176

SCENERY OF SWITZERLAND.

the Rhine, the Inn, and the Enns. One of the great
folds shortly described in the preceding chapter runs
up the Isere , along the Chamouni Valley, up the
Rhone, through the Urseren Thai, down the Rhine
Valley to Chur, along the Inn nearly to Kufstein, and
for some distance along the Enns. Thus, then, five
great rivers have taken advantage of this main fold,
each of them eventually breaking through into a
transverse valley. The origin of the valley is there-
fore not due to the rivers running through it. Again,
as a glance at the foregoing map (Fig. 42) shows,
the great valley of the Aar from the Lake of Neu-
chatel to Coblenz is continued in the course of the
Upper Danube.

The Pusterthal in the Tyrol offers us an interest-
ing case of what is obviously a single valley, slightly
raised, however, in the centre, near Toblach, so that
from this point the water flows in opposite directions
—the Drau eastward, and the Rienz westward. In
this case the elevation is single and slight: in the
main valley of Switzerland there are several water-
sheds, and they are much loftier, still we may, I
think, regard that of the Arve (see Fig. 42) from
Les Houches to the Col de Balme, of the Rhone
from Martigny to its source, of the Urseren Thai, of
the Vorder Rhine from its source to Chur, of the Inn

VALLEYS.

I??

from Landeck to below Innsbruck, even perhaps of
the Enns from Radstadt to Hieflau as in one sense
a single valley, due to one of these longitudinal folds,
but interrupted by bosses of Gneiss and Granite —
one culminating in Mont Blanc, and another in the
St. Gotthard — which have separated the waters of
the Isfre, the Rhone, the Vorder Rhine, the Inn, and
the Enns. That the Valley of Chamouni, the Valais,
the Urseren Thai and the Vorder Rhine really form
part of one great fold is further shown by the pres-
ence of a belt of Jurassic strata nipped in, as it were,
between the Crystalline rocks.

This great valley then, though immensely
deepened and widened by erosion, cannot owe
its origin or direction to river action, because it is
occupied in different parts by different rivers running
in opposite directions. We have in fact one great
valley, but several rivers. It is therefore due to one
original cause; it is, to use a technical term “geotec-
tonic,” and is due to the great lateral compression
from S.E. to N.W. which has thrown Switzerland into
a succession of great folds.

A similar case is that of the Val Ferret. The
depth is no doubt mainly due to erosion, but it
follows the tract of Jurassic strata which lie at the
foot of the great mountain wall of the Mont Blanc

Scenery of Switzerland. I. 1 2

i 7 8

SCENERY OF SWITZERLAND.

range. No one who looks at the map can for an
instant doubt that it is in reality a single valley; but
it falls into three parts — the eastern portion is oc-
cupied by a branch of the Dranse running to the
N. E.; the centre by the Doire running S.W., and
the west by another branch of the Doire running
N.E., the two, meeting at the foot of the Glacier de
la Brenva, fall into a transverse valley and run S.E.
towards Courmayeur and Aosta. Again the great
valley which has given rise to the Lakes of Neu-
chatel and Bienne, and which follows the course of
the Aar from Soleure to Brugg, reappears in the
course of the Danube below Donaueschingen.

In some respects the courses of the rivers indicate
the original configuration of the surface even better
than the mountains.

Many rivers after running for some distance along
the strike (see p. 66) of the strata, change their
direction, not turning in a grand curve, but suddenly
breaking away at right angles, as for instance the
Rhone at Martigny, the Aar near Brugg, the Rhine
near Chur, the Inn near Kufstein.

But why should the rivers, after running for a
certain distance in the direction of the main axis, so
often break away into cross valleys? The explana-
tion usually given is that transverse streams have cut

VALLEYS.

179

their way back, and thus tapped the valley. This is
no doubt true in some cases, but cannot be accepted,
I think, as a general explanation.

Prof. Bonney* called attention to this tendency
in his second lecture on the “Growth and Sculpture
of the Alps.” “On considering,” he says, “the
general disposition of the rocks constituting the
Alpine chain, we perceive that, in addition to the
long curving folds which determine the general direc-
tion of the component ranges, they give indications
of a cross folding. The axis of these minor undula-
tions run from about N.N.E. to S.S.W.”

He suggests three possible explanations: — (1)
“That the Alps are the consequence of a series of
independent movements, not simultaneous, so that
the chain results from the accretion laterally of an
independent series of wave-like uplifts; (2) that the
chain was defined in its general outline by a series
of thrusts proceeding outward from the basin of the
North Italian plain, and afterwards folded transversely
by a new set of thrusts acting at right angles to a
N.N.E. line; (3) that the transverse disturbances are
the older, and that the floor on which the Secondary
deposits were laid down had already been disposed

* Alpine Journal , Nov. 1888.

l8o SCENERY OF SWITZERLAND.

in parallel folds, trending roughly in the above
direction.”

He adopts the third hypothesis. He considers
that the transverse wrinkles were perhaps Triassic,
“not improbably post-Carboniferous,” and therefore
far older than the main longitudinal folds. “Still,”
he continues, “though I incline to this view, the
question is so complicated that I do not feel justified
in expressing a strong opinion, and rather throw out
the idea for consideration than press it for accept-
ance. All that I will say is that I find it impossible
to explain the existing structure of the Alps by a
single connected series of earth movements.”

Under these circumstances I have ventured* to
make the following suggestion. If the elevation of
the Swiss mountains be due to cooling and contrac-
tion leading to subsidence as suggested in page 58,
it is evident, though, so far as I am aware, this has
not hitherto been pointed out, that, as already sug-
gested, the compression and consequent folding of
the strata (Fig. 43) would not be in the direction of
A B only, but also at right angles to it, in the
direction A C, though the amount of folding might
be much greater in one direction than in the other.
Thus in the case of Switzerland, as the main folds
* Beauties of Nattire.

VALLEYS.

1 8 1

run S.W. and N.E. the subsidiary ones would be
N.W. and S.E.

If these considerations are correct it follows that,
though the main valleys of Switzerland have been

c' )

Fig. 43. — Diagram in illustration of Mountain Structure.

immensely deepened and widened by rivers, their
original course was determined by tectonic causes.

Again, they indicate why the long valleys are not
more continuous. If we look for instance at a map
of the Jura, we see that though the ridges follow the
same general curve from one end to the other, they
are not continuous, but form a succession of similar,

i 82

SCENERY OF SWITZERLAND.

but detached ridges. Moreover even when a valley
is continuous for many miles it is interrupted here
and there by the cross folds.

These considerations then seem to account for
the two main directions of the Swiss valleys.

I must add, however, that in Prof. Heim’s opinion
the cross folds occur in other parts of the Earth’s
surface; and such bosses as the Furca and the Ober
Alp are merely the battle-grounds of different river
systems, the lower levels being due to more rapid
denudation.

Cirques.

In some cases valleys end in a steep amphi-
theatre known as a “Cirque.”

Cirques are characteristic - of calcareous districts.
They occur especially where a permeable bed rests
on an impervious substratum. Under such circum-
stances a spring, in many cases intermittent, issues
at the junction and gradually eats back into the
upper stratum, forming at first a semicircular enclave,
which becomes gradually elliptic, and as time passes
on more and more elongated, but always with a
steep terminal slope. In the Jura, cirques are numer-
ous, and in many cases a marly bed supplies the
impermeable stratum.

VALLEYS. 183

The Creux du Vent, and the Cirque de St.
Sulpice are two of the finest examples.

Terraces.

As regards the sides of valleys, other things being
equal, the harder the rocks the steeper will the slope
of the sides be. Very hard rocks indeed are often
almost, or for some distances quite, perpendicular.
The slope may be uniform in cases where the strata
are similar and of great thickness, as for instance in
the valley of the Reuss above Amsteg where the
Bristenstock forms a grand pyramid of Crystalline
rock, or where the slope coincides with the dip of
the strata, as in the valley of Lauterbrunnen, where
the right side of the valley presents immense sheets
of Jurassic rock.

In most cases, however, some of the strata along
the side of the valley are harder than others, and
the consequence is that we have a succession of
terraces; gentler slopes indicating the softer, and
steeper ones the harder beds.

Figs. 44 and 45 show some terraces in the valley
of the Bienne (Jura) due to the presence of hard
calcareous layers.

These “weather” terraces (Figs. 54, 55 pp. 202,
203) must not be confused with the “river terraces”

184

SCENERY OF SWITZERLAND.

which will be described in the next chapter. River
terraces have no relation to the rock and follow the
slope of the river, while weather terraces follow the
lines of the strata.

This consideration throws light on the cases in

which a river valley expands and contracts, perhaps
several times in succession.

We often, as we ascend a river, after passing
along a comparatively flat plain, find ourselves in a
narrow defile, down which the water rushes in an
impetuous torrent, but at the summit of which, to

VALLEYS.

185

our surprise, we find another broad flat expanse.
This is especially the case with rivers running in a
transverse valley, that is to say of a valley lying at

.Fig. 45. — Section showing Weather Terraces.

right angles to the “strike” or direction of the strata
(such, for instance, as the Reuss), the water acts
more effectively than in cross rocks which in many
cases differ in hardness, and which therefore of
course cut down the softer strata more rapidly than

A B C D T 2

Fig. 46. — Diagram showing the course of a river through hard
and soft strata.

the harder ones; each ridge of harder rock will there-
fore form a dam and give rise to a rapid or cataract.
In cases such as these each section of the river has
for a time a “regimen” of its own.

Suppose for instance a river a b (Fig. 46) running

1 86

SCENERY OF SWITZERLAND.

across the strike of several layers differing in hard-
ness, A, C, E, being soft while B, D are tough or
hard. In such a case the valley will widen out at
A, C, E. Speaking generally we may say that the
depth of the valley is mainly due to the river erosion,
the width to weathering. Thus the Urseren Thai on
the St. Gotthard, the broad stretches of valley at
Liddes, and at Chable on the Dranse (Valais), are
due to the more readily disintegrated Carboniferous
or Jurassic strata. On the other hand, the depth of
the valley will tend to arrive at the regular “regimen”
(Fig. 47), and must in any case follow its normal
course; but the width will depend on the de-
structibility of the strata. Even however the hardest
rocks will give way in time, so that the inclination of
the sides will depend on the hardness of the rocks
and the age of the valley. Other things being equal,
the older the valley the gentler will be the slopes of
the sides.

Flat valley plains may be formed either by rivers
or in a lake, and the surface view is the same in
either case. The inner structure, however, as shown
in a section, is very different. A river plain shows
irregular, lenticular masses of gravel and sand. A
stream running into a lake deposits fine mud in
gently inclined layers, but as soon as it comes to the

VALLEYS. 187

water’s edge the coarser gravel rolls downwards form-
ing a steeper slope.

The great Swiss valleys are of immense antiquity ;
the main ones were coeval with the mountains, and
date back to the formation of the Alps themselves.
Many indeed were even deeper in glacial times, hav-
ing been to a great extent filled up by glacial de-
posits. Penck states that longitudinal are generally
older than cross valleys. It seems to me, on the
contrary, that they would as a rule have begun
simultaneously. No doubt, however, there were many
exceptions. The Dranse was probably an older
river than the Upper Rhone. The Rhine below
Basle runs in a comparatively recent depression.
The greater number of the upper Swiss valleys must
however date back to Miocene and some even to
Eocene times, when rapid rivers were bringing down
immense quantities of gravel from the slopes of the
slowly rising Alps.

1 88

SCENERY OF SWITZERLAND.

CHAPTER VII.

ACTION OF RIVERS.

Although the elevation of the Swiss Alps is the
result of geological causes, the present configuration
of the surface is mainly due to erosion and denuda-
tion. It is indeed impossible to understand the
physical geography of any country without some
knowledge of the action of water, and especially of
rivers.

The velocity of a stream depends partly on the
inclination of its bed, and partly on the volume of

Fig. 4 7. — Final Slope of a River.

water; if then we study an ancient river which has
passed the stormy period of childhood, and forced
its way through the obstacles of middle life, so that
its waters run with approximately equal rapidity, we
shall find that the slope diminishes from its source to
the sea or lake into which it falls, with some such
curve as in Fig. 47.

ACTION OF RIVERS.

189

Such a river is said to have attained its “regimen,”
and this is the goal to which all rivers are striving
to arrive.

The course of a river may be divided into three
stages, which may be, and often are, repeated several
times, viz. : —

1. Deepening and widening (the torrent).

2. Widening and levelling (the river proper).

3. Filling up (the delta).

and every part of a river in the second stage has
passed through the first, every one in the third
through the other two.

In the Valais the Upper glacier is a valley in the
second stage, the ice-fall in the first; the plain from
the foot of the fall to the Hotel in the second, from
the Hotel to near Oberwald in the first; from Ober-
wald nearly to Niederwald in the second, from
Niederwald to rather beyond Viesch in the first;
then on to Brieg in the second, and from St. Maurice
to Villeneuve in the third.

First Stage.

In the first phase the river has a surplus of force.
It may be called a torrent. It cuts deeper and
deeper into its valley, and carries away the mud
and stones to a lower level. The sides are steep, as

I go SCENERY OF SWITZERLAND.

steep indeed as the nature of the material will per-
mit, and the valley is in the shape of a V with little,
if any, flat bottom. The water moreover continually
eats back into the higher ground. The character of
the valley depends greatly on that of the strata,
being narrower where they are hard and tough,
broader on the contrary where they are soft, so that
they crumble more easily into the stream under the
action of the weather. Fig. 46.

In several cases indeed the Swiss rivers run
through gorges of great depth, and yet very narrow,
even in some places with overhanging walls. The
Via Mala, which leads from the green meadows of
Schams (Sexamniensis, from its six brooks) to Thusis,
is about five miles in length with a depth of nearly
500 metres, and very narrow, in one place not more
than 9 to 15 metres in breadth.

The gorges of the Aar, of the Gorner, of the
Tamina at Pfaffers, of the Trient, have a similar
character. These were formerly supposed to be
fissures due to upheaval. They none of them how-
ever present a trace of fracture, marks of water action
can in places be seen from the base to the summit,
and there can be no doubt that they have been cut
through by the rivers.

In certain cases indeed we have conclusive

ACTION OF RIVERS.

IQI

evidence. Some of these gorges are left at times
quite dry, and it is easy then to see that the rock is
continuous from side to side. The tunnels on the
§t. Gotthard line pass no less than six times under
the Reuss, and there is no trace of a fault.

It may, I think, be said that the theory which at-
tributed these gorges to a split in the rock is now
definitely abandoned.

Of course, however, there are some cases in
which the courses of streams have been determined
by lines of fault and fracture.

Second Stage.

The second stage commences where the inclina-
tion becomes so slight that the river can scarcely
carry away the loose material brought from above, or
showered down from the sides, but spreads it over
the valley, in which it wanders from side to side,
and which it tends continually to widen. Hence un-
less they are confined by artificial embankments,
such rivers are continually changing their course,
keeping however within the limits of the same valley.
The width of the valley moreover depends on its
age, as well as on the size of the river and the
character of the rock.

If we imagine a river running down a regularly

1Q2

SCENERY OF SWITZERLAND.

inclined plane in a more or less straight line, any in-
equality or obstruction, or the entrance of a side
stream, would drive the water to one side, and when
once diverted it would continue in the new direction,
until the force of gravity drawing the water in a
straight line downwards equalled that of the force
tending to divert its course. Hence the radius of
the curves will follow a regular curve-law depending
on the volume of water and the angle of inclination

Fig. 48.— Diagrammatic Section of a Valley (exaggerated) . R R, Rocky
basis of valley; A A, Sedimentary strata; B, Ordinary level of river-
C, Flood level.

of the bed. If the fall is ten feet per mile and the
soil homogenous, the curves would be so much ex-
tended that the course would appear almost straight.
With a fall of 1 foot per mile the length of the curve
is, according to Fergusson, about six times the width
of the river, so that a river 1000 feet wide would
oscillate once in 6000 feet. This is an important
consideration and much labour has been lost in trying
to prevent rivers from following their natural laws of
oscillation. But rivers are very true to their own

ACTION OF RIVERS.

193

laws, and a change at any part is continued both
upwards and downwards, so that a new oscillation
in any place cuts its way through the whole plain of
the river both above and below.

If the river has no longer a sufficient fall to
enable it to carry off the materials it brings down,
it gradually raises its bed (Fig. 48), hence in the
lower part of their course many of the most celebrated
rivers — the Po, the Nile, the Mississippi, the Thames,
etc.. — run upon embankments, partly of their own
creation.

The Reno, the most dangerous of all the
Apennine rivers, is in some places more than 30
feet above the adjoining country. Rivers under such
conditions, when not interfered with by Man, sooner
or later break through their banks, and, leaving their
former bed, take a new course along the lowest part
of their valley, which again they gradually raise above
the rest.

Along the valley of the Rhone from Visp down
to the Lake of Geneva there is often a marsh on
one side of the valley, sometimes on both, the exist-
ence of which may be thus explained.

This is the second stage.

Scenery of Switzerland. /.

194

SCENERY OF SWITZERLAND.

Third Stage.

Finally, when the inclination becomes too small
the stream cannot carry farther the stones and mud
which it has brought down, and spreads them out
in the form of a fan, forming a more or less flat
cone or delta — a cone if in air, a delta if under
water; and the greater the volume of water, the
gentler will the slope be, so that in great rivers it
becomes almost imperceptible. At this part of its
course, the stream instead of meandering, will tend
to divide into several branches.

Cones and deltas are often spoken of as if they
were identical. The surface and slope are indeed
similar, but the structure of a delta formed under
water (see p. 186) is by no means the same as that
of a cone formed in the air.

Deltas have generally a very slight inclination, so
far as the surface is concerned, while the layers be-
low stand at a greater inclination. Most of the Swiss
Lakes are being gradually filled up by the deposits
of rivers. The Lake of Geneva once extended far
up the Rhone Valley to St. Maurice if not to Brieg.
It presents also a very typical delta at the mouth of
the Dranse near Thonon. Between Vevey and
Villeneuve are several such promontories, each

ACTION OF RIVERS.

195

marking the place where a stream falls into the
lake.

Where lateral torrents fall into a main valley the
rapidity of the current being checked, their power of
transport is diminished, and similar “river cones” are
formed. A side stream with its terminal cone, when
seen from the opposite side of the valley, presents the
appearance shown in Fig. 49, or, if we are looking
down the valley, as in Fig. 50, the river being often
driven to one side of the main valley, as, for in-
stance, is the case in the Valais near Sion, where the
Rhone is (Fig. 51 p. 199) driven out of its course by,
and forms a curve round, the cone formed by the
River Borgne.

The river cones are, in many cases, marked out
by the character of the vegetation. “The Pines en-
joy the stony ground particularly, and hold large
meetings upon it, but the Alders are shy of it, and,
when it has come to an end, form a triumphal pro-
cession all round its edge, following the convex
line.”*

The magnitude of these “river cones” de-
pends on the amount and character of the ma-
terials brought into the main valley, and on the
power of the river to carry them off. The felling of
* Ruskin, Modern Painters, vol. iv.

13*

ACTION OF RIVERS.

197

Fig. 50. — Diagram of an Alpine Valley, showing a River Cone. Lateral view.

SCENERY OF SWITZERLAND.

I98

forests, for instance, in a lateral valley will consider-
ably increase the erosive power of the stream, and
the amount of material brought down. Rocks which
yield readily to the action of weather and water will
naturally supply most material, and give rise to the
largest cones, especially if they form hard pebbles.
On the other hand, the Flysch, which, as a rule,
exeicises little resistance, does not produce such im-
portant cones as might be expected, because it dis-
integrates into fine particles which are easily washed
away. The Cargneule, on the contrary, produces
large cones, because it breaks up readily, but into
hard pieces.

Such cones sometimes raise the bed of the valley
and dam back the water, and thus form a marshy
and unhealthy tract. Thus in the Upper Valais be-
low Oberwald is a succession of such cones, one suc-
ceeding another, and with more or less marshy
ground between them. At Munster there is a fine
cone, and further down are many others at intervals.
The two largest are those of the Illgraben at Leuk,
and the Chamoson at the mouth of the Losentze,
both of which raise the level of the valley above
several feet. That of the Borgne (Fig. 51), near
Sion, drives the river to the foot of the opposite
mountain.

ACTION OF RIVERS.

199

When at length a river has so adjusted its slope
that it neither deepens its bed in the upper portion

of its course, nor deposits materials, it is said to have
acquired its “regimen” (Fig. 47 p. 188), and in such

200

SCENERY OF SWITZERLAND.

a case the velocity will be uniform. The enlarge-
ment of the bed of a river is not, however, in pro-
portion to the increase of its waters as it approaches
the sea. Other things being equal, a river which
incieases in volume, increases in velocity; the
“regimen” therefore would be destroyed, and the
river would again commence to eat out its bed.

Hence, if rivers enlarge, as for instance owing to any
increase in territory, the slope diminishes.

The above figure (Fig. 52) gives a sketch map,
and Fig. 5 3 lepresents the profiles, of the principal
rivers in the valley of the Garonne, and it will be

seen that the larger the river the gentler is the
slope.

At present many of the smaller Swiss streams
are eating into their cones and endeavouring to

ACTION OF RIVERS.

201

flatten them, owing perhaps to the gradual enlarge-
ment of the gathering-grounds.

These cones are favourite sites for villages, which
are thus raised and placed above the range of
ordinary floods. The loose materials of the upper
part of the cone, moreover, absorb water freely in
the upper part, which is filtered, and emerges in
clear springs lower down. Thus arise many of the
fountains in such villages.

Now let us suppose that the force of a river is
again increased, either by a fresh elevation, or locally
by the removal of a barrier, or by an increase in
volume owing to an addition of territory, or greater
rainfall, it will then again cut into its own bed,
deepening the valley, and giving rise to a rapid,
which will creep gradually up the valley, receding of
course more rapidly where the strata are soft, and
lingering longer at any hard ridge.

The old plain of the valley will form a more or

202

SCENERY OF SWITZERLAND.

less continuous terrace above the new course. Such
old river terraces may be seen in most valleys; often
indeed several, one above another. The upper ter-
races being generally cut in the rock, the lower ones
in river deposits or fallen debris.

It has been sometimes supposed that these ter-

races indicate a greater volume of water in ancient
times, sufficient indeed to fill up the whole valley to
that depth. It must be remembered, however, that
the terrace was formed before the lower part of the
valley was excavated.

54 is a section across the valley of the Ticino,
a short distance below Airolo. It shows two high

ACTION OF RIVERS.

203

terraces on which the Lakes Tom and Ritom aie
respectively situated, and which correspond to those
of Campolungo and Tremorgia on the other (W.) side
of the valley. Relow them is another tei race at a
height of 1350 metres, on which Altanca stands, ihis
terrace can be traced for some distance, and bears
a series of villages— Altanca, Ronco, Beggio, Catto,
Osco, etc. In the valley of the Ticino there is a

second series of still more important towns, at, or at
least little above, the present river bed, but in other
cases, as, for instance, along the Plessur, which falls
into the Rhine at Chur, the present river bed is
quite narrow, and the villages are on an old river
terrace high above the present water level.

Fig. 55 represents a group of river terraces in
the Val Camadra.

204

SCENERY OF SWITZERLAND.

In each river system the terraces occupy cor-
responding levels, but in different systems they have
no relation to one another. They afford, as we shall
see in the next chapter, valuable evidence as regards
the former history of rivers.

Hitherto I have assumed that the river deepens
its bed vertically. This is not, however, always the
case. If the strata are inclined the action of the

Fig. 56.— Diagram of River Valley.

water will tend to follow the softer stratum, as for
instance, in the following diagram, where A represents
a harder calcareous rock overlying a softer bed B.

The enormous amount of erosion and denudation
which has taken place may be estimated from the
fact that terraces can still be traced in some cases

at a height of 3000 metres above the present river
beds.

As we approach their source, valleys become

ACTION OF RIVERS.

205

steeper and steeper. In some cases, and especially
in calcareous districts, the valleys end in a precipitous,
more or less semicircular “Cirque.” Springs rising
at the foot of such escarpments are known as Vau-
clusian, from the celebrated and typical instance at
Vaucluse.

Another interesting point brought out by the
study of Swiss rivers, is that just as in Geology,
though there have no doubt been tremendous cata-
clysms, still the main changes have been due to the
continuous action of existing causes; so also in the
case of rivers, however important the effects produced
due to floods, still the configuration of river valleys
is greatly due to the steady and regular flow of the
water.

Floods may be divided into two classes, (1) those
due to the bursting of some upper reservoir, such,
for instance, as the great flood of the Dranse de
Bagnes in 1818, due to the outburst of the lake,
which had been dammed back by the glacier of
Gietroz, or the more recent flood of St. Gervais
owing to the bursting of a subglacial reservoir in the
little Glacier de T6te Rousse which rushed down the
valley in the dead of the night, in a few minutes
swept away the Baths, and drowned most of the
visitors; and (2) those due to heavy rains. No one

206

SCENERY OF SWITZERLAND.

can travel much in Switzerland without seeing the
great precautions taken to confine the rivers within
certain limits. In fact, what we call the river bed,
is rather the low-water channel, and the whole bottom
of the valley would, but for these precautions, be
covered during any considerable flood. Egypt itself
is the river bed of the Nile during the autumn flood.

Giants’ Caldrons.

These are more or less circular cavities, often
somewhat raised in the centre. They sometimes
attain a considerable size — as much as 8 metres in
diameter and 5 in depth. There is a very fine group
at Lucerne, where they are known as the “ Jardin du
Glacier.” They have been excavated in the rock by
blocks of harder stone being whirled round by the
action of water. Some of them no doubt, and cer-
tainly those at Lucerne, were formed under glaciers,
at the foot perhaps of a “moulin,” but I believe that
as a rule they were formed in streams.* Several
have recently been discovered at the Maloja; there
are some fine specimens also near Servoz in the
valley of the Arve. Renevier points out that such
caldrons can be seen actually in process of formation
in some of the existing rivers, as, for instance, near
* Favre, Reck. Geol., vol. I.

ACTION OF RIVERS.

207

the junction of the Rhone and the Valorsine below
Geneva. These, however, will be destroyed as erosion
continues. Surprise is sometimes expressed that
Giants’ Caldrons occur where no stream now flows.
But it is just to this fact that they owe their existence.
If the river had not changed its course they would
long since have been destroyed.

Before closing this chapter I must say a few
words about subterranean streams. These occur
mainly in porous rocks, such as those of the Jura.
The most considerable of these partly subterranean
rivers is the Orbe, which rises originally in a little
French lake, Les Rousses, traverses two others on
Swiss territory, the Lake de Joux, and that of Brenet,
and then disappears suddenly in the ground at the
foot of a high cliff, reappearing again at a distance
of 3 km. near Vallorbes.

Summing up this chapter we may say that as
soon as any tract of land rose out of the sea, the
rain which fell on the surface would trickle down-
wards in a thousand rills, forming pools here and
there, and gradually collecting into larger and larger
streams. Whenever the slope was sufficient, the
water would begin cutting into the soil and carrying
it off to the sea. This action would, of course, differ
in rapidity according to the slope and hardness of

208

SCENERY OF SWITZERLAND.

the ground. The character of the valley would de-
pend greatly on the nature of the strata, being narrow
where they were hard and tough; broader, on the
contrary, where they were soft, so that they crumbled
readily into the stream, or where they were easily
split by the weather. Gradually the stream would
eat into its bed until it reached a certain slope, the
steepness of which would depend on the volume of
water. The erosive action would then cease, but the
weathering of the sides and consequent widening
would continue, and the river would wander from
one part of the valley to another, spreading the
materials and forming a river plain. At length, as
the rapidity still further diminished, it would no longer
have sufficient power even to carry off the materials
brought down. It would form therefore a cone or
delta, and instead of wandering would tend to divide
into different branches.

When we look at some great valley of denuda-
tion and the comparatively small river which flows
through it, we may deem it almost impossible that
so great an effect can be due to so small a cause.
We find, however, every gradation from the little
gully cut out by the last summer shower up to the
great Canon of Colorado. We have to consider not
only the flow of the water, but the lapse of time,

ACTION OF RIVERS.

20g

and remember that our river valleys are the work of
ages. Moreover, even without postulating any greater
rainfall in former times, we must bear in mind that
we are now looking at rivers which have attained or
are approaching their equilibrium; they are com-
paratively steady, and even aged; so that we cannot
measure their present effect by that which they
produced when they possessed the energy and im-
petuosity of youth.

From this point of view the upper part of a river
valley is peculiarly interesting. It is a beautiful and
instructive miniature. The water forms a sort of
small-meshed net of tiny runnels. We can as it
were surprise the river at its very commencement;
we can find streamlets and valleys in every stage, a
quartz pebble may divert a tiny stream, as a moun-
tain does a great river; we find springs and torrents,
river terraces and waterfalls, lakes and deltas in the
space of a few square metres, and changes pass
under our eyes which on a larger scale require thou-
sands of years.

And as we watch some tiny rivulet, swelling
gradually into a little brook, joined by others from
time to time, growing to a larger and larger torrent,
then to a stream, and finally to a great river, it is
impossible to resist the conclusion gradually forced

Scenery of Switzerland. /. 14

2 IO

SCENERY OF SWITZERLAND.

upon us, that, incredible as it must at first sight
appear, even the greatest river valleys, though their
origin may be due to the original form of the sur-
face, owe their present configuration mainly to the
action of rain and rivers.

Note . — Throughout western Europe a large pro-
portion of the river names fall. into three groups.

From the Old German Aha, Celtic Uisge, Gaelic
Oich, Latin Aqua (Water), softened into the French
Eau, we have the Aa, Awe, Au, Avon, Aue, Ouse,
Oise, Grand Eau, Aubonne, Oich, Ock, Aach, Esk,
Uisk, etc.

From the Celtic Dwr (Greek vdcog), we have
Oder, Adour, Thur, Dora, Douro, Doire, Durance,
Dranse, Doveria, etc.

From the Celtic Rhin, or Rhedu, to run (Greek
geco), we have the Rhine, Rhone, Reuss, Reno, Rye,
Ray, Raz, etc.

The names Aa and Drance or Dranse are so
common in Switzerland that it is necessary to specify
them by some further description, such as the Engel-
berger Aa, the Aa of Alpnach, the Milch Aa, Hall-
wyler Aa, Waggithaler Aa, etc.

The Drance which falls into the Lake of Geneva
near Thonon is perhaps the Drance par excellence,

ACTION OF RIVERS.

21 I

but in the same river system we have also the
Drance de Bagne, the Drance d’Entremont, and the
Drance de Ferret.

In the case of the Rhine also there is the Vorder
Rhein, Mittel Rhein, Hinter Rheiri, Oberhalbstein
Rhein, Averser Rhein, Safien-Rhein, etc.

212

SCENERY OF SWITZERLAND.

CHAPTER VIII.

DIRECTIONS OF RIVERS.

The general direction of the river-courses in any
country is determined in the first instance by the
configuration of the surface at the time of its be-
coming dry land. The least inequality in the
surface would affect the first direction of the
streams, and thus give rise to channels, which would
be gradually deepened and enlarged. They are,
however, in many cases materially modified by sub-
sequent changes of relative level, and by the results
of erosion, which acts of course much more rapidly
on some strata than on others. It is as difficult,
however, for a river as it is for a man to get out of
a groove.

If we imagine a district raised in the form of a
regular dome, the rivers would radiate from the
summit in all directions. The lake district in the
north of England; the Plateau of Lanneme-zan in
the south of France, and the Ellsworth Arch in the
Henry Mountains,* offer us approximations to such
* See Gilbert, Geology of the Henry Mountains .

DIRECTIONS OF RIVERS.

213

a condition. It seldom happens, however, that the
case is so simple, and the lines of rivers offer many
interesting problems, which are by no means easy to
solve.

As already mentioned ( atite , p. 174)1 the Swiss
rivers follow two main directions, at right angles to
one another, namely, S.W. by N.E. and N.W. by S.E.
The first follows the strike of the strata. The ex-
planation of the second is not so simple. The pro-
bable cause, however, which has determined the two
main directions of the Swiss rivers has been already
suggested {ante, p. 181).

The principal Swiss rivers must be of great
antiquity. Some of the streams in the eastern and
central parts of the Alps probably commenced even
in Eocene times. The Nagelflue was brought down
from the mountains by rivers which probably oc-
cupied the upper parts of the valleys of the Aar,
Reuss, etc.

Nevertheless there have been great changes in
the courses of the Swiss rivers. These are ascribable
to four main causes: — First, it must be remembered
that streams are continually eating back into the
hills. In many cases they cut completely through
them, and if the valley into which they thus force
their way is at a higher level, they carry off the

214

SCENERY OF SWITZERLAND.

upper waters; Secondly, later earth movements in
many cases changed the course of the rivers;
Thirdly, they have in many cases been diverted by
masses of glacial deposits; and Fourthly, the summit
ridge of the Alps is slowly retreating northwards,
which affects the river system of all the upper dis-
tricts.

In the great Swiss plain the country slopes on
the whole northwards from the Alps, so that the
lowest part is that along the foot of the Jura.
Hence (Fig. 42) the main drainage runs along the
line from Yverdun to Neuchatel, down the Zihl to
Soleure, and then along the Aar to Waldshut. The
Upper Aar, the Emmen, the Wigger, the Suhr, the
Wynen, the lower Reuss, the Sihl, and the Limmat,
besides several smaller streams, running approximately
parallel to one another — N.N.W., and at a right angle
with the main axis of elevation, all join the Aar from
the south, while on the north it does not receive a
single tributary of any importance.

On the south side of the Alps again, and for a
corresponding reason , all the great affluents of the
Po — the Dora Baltea, the Sesia, the Ticino, the
Olonna, the Adda, the Adige, etc., come from the
north, and run S.S.E. from the axis of elevation to
the Po.

DIRECTIONS OF RIVERS.

215

Indeed, the general slope being from the ridge
of the Alps towards the north, most of the large
affluents of rivers running in longitudinal valleys
fall in on the south, as, for instance, those of the
Ist;re from Albertville to Grenoble, of the Rhone
from its source to Martigny, of the Vorder Rhine
from its source to Chur, of the Inn from Landeck
to Kufstein, of the Enns from its source to near
Admont, of the Danube from its source to Vienna,
and, as just mentioned, of the valley from Yverdun
to Waldshut. Hence also, whenever the Swiss rivers
running east and w'est break into a transverse valley,
as the larger ones all do, and some more than once,
they invariably, whether originally running east or
west, turn towards the north.

But why has the plain of Switzerland this slope?
Why is it lowest along the wall of the Jura? As
has been already pointed out, this part of Switzer-
land was formerly a sea, which was gradually filled by
river deposits'. It is indeed a great “cone” due to
many rivers which flowed down from the rising Alps.
This being so, the general slope is naturally up to,
and the lowest part is that farthest away from, the
mountains.

In considering the courses of rivers it must be
remembered that the strata situated below by no

2l6

SCENERY OF SWITZERLAND.

means always correspond with those at a higher level.
Again it will sometimes happen that rivers follow a
course which is very difficult to explain, because, in
fact, it has no reference to the present configuration
of tire surface, but has been determined by the
existence of strata which have now disappeared.

Fig. 57. Diagram to illustrate a river now running in an anticlinal.

It often happens, for instance, that the rivers
now run apparently on an anticlinal, and have a
synclinal on one side (Fig. 57), as, for instance, the
Rhine at Dissentis (see Fig. 134, vol. 11. p. 191).

The folds, however, being inclined, it will be seen
from the dotted lines (Fig. 57) that when the river
began its labour it perhaps did run in the synclinal,
but having cut its way directly downwards is now

DIRECTIONS OF RIVERS.

217

some way from it, and will diverge further and
further as erosion proceeds.

It is a remarkable fact that great folds by no
means always determine the watershed, but, on the
contrary, rivers often cut through ranges of moun-
tains.

Thus the Elbe cuts right across the Erzgebirge,
the Rhine through the mountains between Bingen
and Coblenz, the Potomac, the Susquehannah, and
the Delaware through the Alleghanies. Even the
chain of the Himalayas, though the loftiest in the
world, is not a watershed, but is cut through by
rivers in more than one place. The case of the
Dranse will be alluded to further on. In these in-
stances the rivers probably preceded the mountains.
Indeed, as soon as the land rose above the waters,
rivers would begin their work, and having done so,
if a subsequent fold commenced, unless the rate of
elevation exceeded the power of erosion of the river,
the two would proceed simultaneously, so that in
many cases the river would not alter its course, but
would cut deeper and deeper as the mountain range
gradually rose.

In some other cases where we speak of a
river suddenly changing its direction, it would be
more correct to say that it falls into the valley of

2 I 8

SCENERY OF SWITZERLAND.

another stream. Thus the Aar, below Berne, instead
of continuing in the same direction, by what seems
to have been its ancient course, along the broad
valley now only occupied by the little Urtenenbach,
suddenly turns at a right angle, falling into the valley
of the Sarine, near Oltigen.

Take again the Rhone (Fig. 58). It is said to
turn at a right angle at Martigny, but in reality it
falls into and adopts the transverse valley, which
properly belongs to the Dranse; for the Dranse is
probably an older river and ran in the present course
even before the origin of the Valais. This would
seem to indicate that the Oberland range is not so
old as the Pennine, and that its elevation was so
gradual that the Dranse was able to wear away a
passage as the ridge gradually rose. After leaving
the Lake of Geneva the Rhone follows a course
curving gradually to the south, until it falls into and
adopts a valley which properly belongs to the Val-
serine, and afterwards another belonging to the little
river Guiers; it subsequently joins the Ain, and
finally falls into the Saone. If these valleys were
attributed to their older occupiers, we should there-
fore confine the name of the Rhone to the portion of
its course from its source to Martigny.

From Martigny it invades successively the val-

DIRECTIONS OF RIVERS.

2ig

leys of the Dranse, Valserine, Guiers, Ain, and Saone.
In fact, the Saone receives the Ain, the Ain the
Guiers, the Guiers the Valserine, the Valserine the
Dranse, and the Dranse the Rhone. This is not a
mere question of names, but also one of antiquity.
The Saone, for instance, flowed past Lyons to the

Mediterranean for ages before it was joined by the
Rhone. In our nomenclature, however, the Rhone
has swallowed up the others. This is the more
curious from the fact that of the three great rivers
which unite to form the lower Rhone, namely, the
Saone, the Doubs, and the Rhone itself, the Saone

220

SCENERY OF SWITZERLAND.

brings for a large part of the year the greatest volume
of water, and the Doubs has the longest course.

We will now consider some of the cases in which

Swiss rivers have altered their courses. In some of
these the change of direction is doubtless due to
the fact that some stream at the lower level, or with

DIRECTIONS OF RIVERS.

221

a greater fall, has eaten its way back, and so tapped
the higher valley.

Rivers, indeed, have their adventures and vicis-

situdes, their wars and invasions. Take, for instance,
the Upper Rhine (Fig. 59), of which we have a
very interesting account by Heim. It is formed of

222

SCENERY OF SWITZERLAND.

three main branches, the Vorder Rhine, the Hinter
Rhine, and the Albula. The two latter, after meet-
ing near Thusis, unite with the Vorder Rhine at
Reichenau, and run by Chur, Mayenfeld, and Sargans
into the Lake of Constance at Rheineck. At some
former period, however, the drainage of this district
was very different.

The Vorder and Hinter Rhine united then, as
they do now, at Reichenau, but at a much higher
level, and ran to Mayenfeld (Fig. 60), not by Chur,
but by the Kunkels Pass to Sargans, and so onwards
not to the Lake of Constance, but to that of Zurich.
The Landwasser at that time rose in the Schlap-
pina Joch, and after receiving as tributaries the
Vereina and the Sardasca, joined the Albula, as it
does now at Tiefenkasten; but instead of going round
to meet the Hinter Rhine near Thusis, the two to-
gether travelled parallel with, but at some distance
from, the Hinter Rhine, by Heide to Chur, and so
to Mayenfeld.

As we look up from Tiefenkasten towards Heide
and the Parpan Pass it seems almost incredible that
the Oberhalbstein Rhine can ever have taken that
course. I give therefore (Fig. 61) the following pro-
file showing the old river terrace, but with the height
exaggerated in comparison with the distance. This,

fli

2 24 SCENERY OF SWITZERLAND.

however, does not affect the relative elevations. The
dotted lines follow the natural slope of a river, and
the strengthened parts show where portions of ter-
race still remain. It is obvious that before the
ancient Schyn had cut its way up to Tiefenkasten
the Oberhalbstein Rhine and the Landwasser flowed
over the Parpan Pass, and not only flowed over it,
but have cut it down some 610 metres, that is to
say, when the river flowed over it with its natural
regimen in relation to the valley it was at a height
of 2200 metres, and has left a fragment of terrace
at that height at Urder Angstberg, the Parpan itself
being only 1500 metres.

In fact, the Parpan and Kunkels passes are de-
serted river valleys, showing on each side river ter-
races, and were obviously once the beds of great
rivers, very different from the comparatively small
streams which now run in their lower parts.

In the meanwhile, however, the Landquart
stealthily crept up the valley, attacked the ridge
which then united the Casanna and the Madrishorn,
and gradually forcing the passage between Dorfli
and Klosters, invaded the valleys of the Schlappina,
Vereina, and Sardasca, absorbed them as tributaries,
detached them from their allegiance to the Land-

DIRECTIONS OF RIVERS. 225

wasser, and annexed the whole of the upper province,
which had formerly belonged to that river.

The Schyn also gradually worked its way up-
wards from Thusis till it succeeded in sapping the
Albula, and carried it down the valley to join the
Vorder Rhine near Thusis. In what is now the
main valley of the Rhine above Chur, another stream
ate its way back, and eventually tapped the main
river at Reichenau, thus diverting it from the Kunkels
and carrying it round by Chur.

It is possible that in the distant future the Land-
wasser may be still further robbed of its territory.
The water of the Davos Lake, the Fltlela, the Dischma,
and the Kuhalpthal now take a very circuitous route
to Chur, and it is not impossible that they may be
captured and carried off by the Plessur.

At Sargans a somewhat similar process was re-
peated, with the addition that the material brought
down by the Weisstannen, or perhaps a rockfall, de-
flected the Rhine, just as we have seen {ante, p. 198)
that the Rhone was pushed on one side by the Borgne.
The Rhone, however, had no choice, it was obliged
to force, and has forced, its way over the cone de-
posited by the Borgne. The Rhine, on the con-
trary, had the option of running down by Vaduz to
Rheineck, and has adopted this course.

Scenery of Switzerland. /. 1 5

226

SCENERY OF SWITZERLAND.

The association of the three great European rivers
■ — the Rhine, the Rhone, and the Danube — with the
past history of our race, invests them with a singular
fascination, and their own story is one of much in-
terest. They all three derive part of their upper
waters from the group of mountains between the
Galenstock and the Bernardine, within a space of
a few miles; on the east the waters now run into the
Black Sea, on the north to the German Ocean, and
on the west to the Mediterranean. But it has not
always been so. Their head-waters have been at one
time interwoven together.

The present drainage of Western Switzerland is
very remarkable. If you stand on a height over-
looking the valley of the Arve near Geneva, you see
a semicircle of mountains — the Jura, the Vuache, the
Voirons, etc., which enclose the west end of the Lake
of Geneva; the Arve runs towards the lake, which
itself opens out towards Lausanne, where a tract of
low land alone separates it from the Lake of Neu-
chatel and the valley of the Aar. This seems the
natural outlet for the waters of the Rhone and the
Arve. As a matter of fact, however, they escape
from the Lake of Geneva at the western end, through
the remarkable defile of Fort de l’Ecluse and Mau-
pertuis, which has a depth of nearly 300 metres,

DIRECTIONS OF RIVERS.

227

and is at one place not more than 14 feet across.
There are reasons, moreover, as we shall see pre-
sently, for considering the defile to be of com-
paratively recent origin. Moreover, at various points
round the Lake of Geneva, remains of lake terraces
show that the waters once stood at a level much
higher than at present. One of these is rather more
than 76 metres above the lake.

The low tract between Lausanne and Yverdun
has a height of 76 metres (250 feet) only, and
corresponds with the above-mentioned lake terrace.
The River Venoge, which rises between Rolle and
the Mont Tendre, runs at first towards the Lake of
Neuchatel, but near La Sarraz it divides; the valley
continues in the same direction, and some of the
water joins the Nozon, which runs to the Lake of
Neuchatel at Yverdun; but the river itself turns
sharply to the south, and falls into the Lake of
Geneva to the east of Morges.

It is probable, therefore, that when the Lake of
Geneva stood at the level of the 76 metres terrace
the waters ran out, not as now at Geneva and by
Lyons to the Mediterranean, but near Lausanne by
Cissonay and Entreroches to Yverdun, and through
the Lake of Neuchatel into the Aar and the Rhine.

But this is not the whole of the curious history.

15*

228

SCENERY OF SWITZERLAND.

At present the Aar makes a sharp turn to the west
at Waldshut, where it falls into the Rhine, but there
is some reason to believe that at a former period,
the river continued its course eastward to the Lake
of Constance, by the valley of the Klettgau, as is
indicated by the presence of gravel beds containing
pebbles which have been brought, not by the Rhine
from the Orisons, but by the Aar from the Bernese
Oberland, showing that the river which occupied the
valley at that time was not the Rhine but the Aar.
It would seem also that at one time the Lake of
Constance stood at a considerably higher level, and
that the outlet was, perhaps, from Friedrichshafen
to Ulm, along what are now the valleys of the
Schussen and the Ried, into the Danube.*

The River Aach, though a tributary of the Rhine,
still derives its head-waters from the valley of the
Danube. A part of the water of the Danube sinks
into fissures in the Jurassic rocks at Immendingen,
and makes its appearance again as copious springs
at Aach, from whence they flow into the Lake of
Constance near Rudolphzell.

Thus the head-waters of the Rhone appear to
have originally run between Morges and Lausanne

Du Pasquier, Beitr. z. Geol. K. d. Sckw., L. XXXI.

DIRECTIONS OF RIVERS.

229

and to the Lakes of Neuchatel and Constance into
the Danube, and so to the Black Sea. Then, after
the present valley was opened between Waldshut and
Basle, they flowed by Basle and the present Rhine,
and after joining the Thames, over the plain which
now forms the German Sea into the Arctic Ocean

Feet
12305 -

9833 -

8194 -

6555 -

4916 -

3277 -

1639 -

Fig. 62. — Section across the Val d’Entrcmont at Bourg St. Pierre.
1=100,000.

between Scotland and Norway. Finally, after the
opening of the passage at Fort de l’Ecluse, by
Geneva, Lyons, and the valley of the Saone, to the
Mediterranean.

In the upper parts of the district there have also
been some changes.

Fig. 6 2 shows the river terraces on the Dranse

230

SCENERY OF SWITZERLAND.

d’Entremont, near Botirg St. Pierre, where the Society
for the protection of Alpine plants have established a
very interesting Alpine garden, and (Fig. 63) those
further down the valley near La Douay.

The uppermost of these terraces is at a height
of 2200 metres. The col leading to the Vallee de

Fig. 63. — Cross section of the Valley of the Dranse, between the Valley
of Champey, Sembranchier and Orsieres.

Champey is at a height of about 1500 metres, and
until the river had reached a lower level than this,
the waters of the Dranse followed what the map
shows was their natural course down the Vallee de
Champey. Eventually, however, the Orsieres branch
of the Dranse de Bagne cut its valley back and
carried off the upper waters to join the Dranse de

DIRECTIONS OF RIVERS.

231

Bagne at Sembranchier. This was facilitated by the
comparative softness of the Jurassic strata and Grey
Schists, while the Vallee de Champey is in Protogine,
Felsite, and Porphyry, which offered a much greater
resistance to the action of the water.*

The Trient also has changed its course. Originally
it ran over the Col de la Forclaz down to Martigny.
In this case the change is due, not to any difference
in the hardness of the rock, but to the greater fall,
and consequently greater erosive power, of the Eau
Noire.

It would also seem that some of the Vaud and
Friburg rivers must be older than the final elevation
of the mountains at the north-east end of the Lake
of Geneva. Gillieron points out that the Broye, the
Mionnaz, the Flon, and I may add the Sarine, from
Sarnen to below Chateau d’Oex, run towards the
Lake of Geneva, until they are stopped by the
mountains between Chatel St. Denis and the Rocher
de Naye, and forced to return northwards.

There is also one important change which applies
to the whole crest of the Alps.

Watersheds are at first determined by the form
of the earliest terrestrial surface, and if the slopes in

* Bodmer, p. 21.

23 2

SCENERY OF SWITZERLAND.

each side are equal they will be permanent; on the
other hand if, as in the Alps, one side is much
steeper than the other, it will be worn back more
rapidly. Hence the whole crest of the Alps is, though
of course very slowly, moving northwards. This is
specially marked in the case of the Engadine (see
vol. ii. p. 240).

These changes and struggles have by no means
come to an end. In some cases we can already
foresee future changes. For instance, the Nolla,
which falls into the Hinter Rhine at Tliusis, is rapidly
eating back into the mountains near Glas, and in,
geologically speaking, a comparatively short time it
will probably invade the Valley of the Versam, carry
off its upper feeders, and appropriate the waters from
the upper valley. So rapidly is the change progress-
ing that after even a few hours’ rain the Nolla be-
comes quite black. In its upper part the Biindner-
schiefer is saturated with water, and reduced almost
to a black mud. The ground may be said to be
continually in slow movement down to the valley, and
the houses of Glas and Tschappina have to be con-
tinually repaired. Some have moved as much as
60 metres downwards in thirty years.

DIRECTIONS OF RIVERS.

233

Age of Rivers.

It follows from these considerations not only that
some Swiss rivers are of comparatively recent origin,
while others date back to very great antiquity, but
that different parts of what is now considered a
single river are of very different ages and have a
very different history.

The southern part of the Central Alps are sup-
posed to have been first raised above the waters,
and to have formed an Island in Eocene times, to
which therefore some of the head-waters date back.
It is, however, clear that the rivers crossing the
Miocene deposits of Central Switzerland cannot have
commenced until after the Miocene strata had been
raised and become dry land. In fact the upper
parts of the Reuss and the Aar probably represent
the rivers which brought down the great masses ot
Miocene gravel which now form the lowlands of
Switzerland, and through which they subsequently
cut the lower parts of their courses. These therefore
must necessarily be of much less ancient origin; but
even these valleys were as a rule excavated to their
full depth before the Glacial period, and must there-
fore be of immense antiquity.

234

SCENERY OF SWITZERLAND.

CHAPTER IX.

LAKES.

The Alps are surrounded by a beautiful circle of
lakes. We have on the north, besides many smaller
ones, those of Constance, Walen and Ztirich, Zug,
Lucerne, Brienz and Thun, Geneva; on the south
the Lago Maggiore, Lugano, Como, Iseo, and Garda,
all seeming to radiate as it were from the great
central mass of the St. Gotthard. I do not mention
the Lakes of Neuchatel or Morat, because they be-
long to a different category.

These great lakes are clearly not parts of a former
inland sea. They stand at very different levels. The
Lake of Brienz, for instance, is 190 metres above
that of Geneva; that of Orta is 225 metres above the
Lake of Garda.

But in considering the origin of these lakes we
must have regard not merely to the surface level of
the water, but also that of the bottom. When we
give the level of a lake it is usual to quote that of
the upper surface, but the bottom is perhaps even

LAKES.

235

more important, and as we shall see from the follow-
ing table, there is a great contrast between the two:—

Surface Level.

Constance

395 metres

Walen

423

„

Zurich

409

Zug

4 1 7

Lucerne

437

>»

Sempach

5°7

Brienz

566

Thun

56°

Geneva

375

Neuchatel

432

»J

Bienne

434

Orta

290

Maggiore

194

»>

Como

199

Lugano

266

Varese

239

Iseo

i 85

Garda

Greatest Depth.

Bottom Level

252 metres

143 metres

151

»»

272 „

142

267 „

198

219 ..

214

223 „

420 „

261

305 »

217

343 »

3°9

66 „

'53

279 »

36° „

'43

147 >.

655

-461 „

414

-215 »»

288

— 22 „

210 „

346

— 161

346

-281 „

These depths are the more remarkable if we
compare them with certain seas. For instance, the
English Channel is nowhere more than 50 metres in
depth, the North Sea, 60.

The original depth of the Lakes was, moreover,
even greater, because the present bottom is in every
case covered by alluvium of unknown, but no doubt

considerable, thickness.

236

SCENERY OF SWITZERLAND.

The Lakes of Neuchatel and of Bienne only
differ by 1 metre as regards the water level, but
the Neuchatel basin is 60 metres deeper than that
of Bienne.

The great Italian lakes, as shown in the fore-
going table, descend below, sometimes much below,
the sea level.

The lakes, moreover, are in some cases true rock
basins. In the case of Geneva, for instance, though
the actual outlet is over superficial debris the solid
rock appears in the river bed at Vernier only 10 metres
below the surface of the lake, or 300 metres above
the deepest part.

The materials brought down by the rivers have
not only raised the bottoms of the lakes, but have
diminished their area by filling them up in part,
especially at the upper ends. It is evident that they
were at one time much larger than they are now.
The Lake of Geneva extended at least to Bex and
perhaps to Brieg, that of Brienz to Meiringen, of
Lucerne to Erstfeld, the Walensee to Chur, the Lake
of Constance at least to Feldkirch, the Lago Maggiore
to Bellinzona, that of Como to Chiavenna,

Moreover, the lakes of Brienz and Thun formed
one sheet of water, as also did the Walensee and the
Lake of Zurich.

LAKES.

237

Very slight changes might again greatly enlarge
the lakes. For instance, if the narrow outlet of the
Aar, somewhat below Brugg, were again closed, a
great part of the central Swiss plain would be sub-
merged.

The problem of the origin of lakes is by no
means identical with that of rivers. We have not
only to account for the general depth of the valley

this may be due to running water — but for the

exceptional basin of the lake; running water produces
valleys, it tends to fill up and drain lakes.

To what then are lake basins due?

It used to be supposed that many lakes were
due to splits and fractures. I do not, however, know
of any Swiss lake which can be so explained.

We may divide Lakes into four classes:

1. Lakes due to changes of level.

2. Lakes of embankment.

3. Lakes of subsidence.

4. Crater lakes.

In many cases, however, a lake may be due partly
to one of these causes and partly to another, and for
convenience of description they may be dealt with
under eight heads: —

1. Those due to irregular accumulations of drift;
these are generally small and shallow.

238

SCENERY OF SWITZERLAND.

2. Corrie lakes.

3. Those due to moraines.

4. Those due to rockfalls, landslips, river cones,'
glaciers, or lava currents damming up the course of
a river.

5. Loop lakes.

6. Those due to subterranean removal of soluble
rock, such as salt, or gypsum. These principally
occur in Triassic areas.

7. Crater lakes.

8. The great lakes.

1. As regards the first class, we find here and
there on the earth’s surface districts sprinkled with
innumerable shallow lakes of all sizes, down to mere
pools. Such, for instance, occur in the district of
Le Pays de Dornbes between the Rhone and the
Saone, that of La Sologne near Orleans, in parts of
North America, in Finland, and elsewhere. Such
lakes are, as a rule, quite shallow. They are due to
the fact of these regions having been covered by
sheets of ice which strewed the land with irregular
masses of clay, gravel, and sand, on a stratum im-
pervious to water, either of hard rock such as granite
or gneiss, or of clay, so that the rain cannot percolate

LAK.ES.

239

through it, and where there is not sufficient inclina-
tion to throw it off.

2. Corrie lakes may be thus explained. Let us
assume a slope (Fig. 64, a, b, c, d) on which snow
and ice ( e ) accumulates.

The rocks and fragments falling from the heights
would accummulate at d. Moreover, the ice would

tend to form a hollow at c (Fig. 65) where the
pressure would be greatest.

If subsequently the snow and ice melted, water
would accumulate in the hollow (Fig. 66), and lakes
thus formed are common in mountainous districts,
where they have a special name— Corries in Scot-
land, Oules in the Pyrennees, Botn in Norway, Kar-
wannen in the German Alps, etc.

3. A third class of lakes is that due to river val-

240

SCENERY OF SWITZERLAND.

leys having been dammed up by the moraines of
ancient glaciers.

To this cause are due the Lake of Zurich (in
part), the Lake of Halhvyl, of Sempach, several of
the Italian lakes (Iseo, Orta), and many others. In
fact, most of the valleys descending from the Alps
have, or have had, a lake where they open on to
the Plain.

4. The fourth class of lakes were once even more
numerous in Switzerland than at present. As cases
of lakes due to rockfalls, I may mention the Torler
See, near Zurich, and the Klon See in Glarus; among
those due to river-cones the Sarnen See, and the
lakes of the Upper Engadine; and as instances of
lakes dammed back by glaciers the Lake of Tacul
on the Mont Blanc range, and the Merjelen See,
which is dammed back by the Aletsch glacier. In
our own country the margins of such an ice-dammed
lake form the celebrated “parallel roads of Glenroy.”

5. Loop lakes occur along the course of many
large rivers. The stream begins by winding in a
loop which almost brings it back to the same point.
The narrow neck is then cut through and the loop
remains as a dead river channel, or “Mortlake.”
Again, when an island is formed in mid-channel, one

LAKES.

24I

one of the side streams is often cut off, and forms a
curved piece of standing water.

6. Subsidence lakes, as already mentioned, occur
principally in Triassic areas. The gypsum or salt is
dissolved away in places, and eventually the ground
gives way, leaving funnel-shaped hollows.

Such a pool was actually formed near the village
of Order in the Chablais in the year i860. There
had previously been a strong spring giving rise to a
stream. Suddenly the ground fell in, forming a pond
about 20 metres long and 8 wide. Three fine chest-
nut trees were engulfed, and the pool was so deep
that at 20 metres no bottom was found, nor were
even the tops of the trees touched.*

These hollows are generally small, though in some
cases, as for instance the Konigssee, the Lakes of
Cadagno and Tremorgia in the Ticino, they are of
considerable dimensions. Our Cheshire Meres are
mainly due to the same cause.

7. Lakes occupying craters are far from infrequent
in Volcanic regions, as for instance in the Auvergne,
the celebrated Lake Avernus in the district of Naples,
and the Maare of the Eifel. There are, however, no
crater lakes in Switzerland.

* Favre, Rech . Geol vol. II.

Scenery of Switzerland. I.

242

SCENERY OF SWITZERLAND.

8. As regards the greater Swiss lakes there has
been much difference of opinion.

Ramsay and Tyndall maintained that they were
rock basins excavated by glaciers.

Mortillet and Gastaldi* have suggested that the
valleys were in pre-glacial times filled with alluvium,
and that this soft material has been ploughed away
by the glaciers.

“That glaciers rub down rocks,” says Sir A. Geikie,
“is demonstrated by the roches moutonnees which they
leave behind them.”

“Taking the case of a glacier,” says Tyndall,
“300 metres deep (and some of the older ones
were probably three times this depth), and allowing
12.20 metres of ice to an atmosphere, we find that
on every square yard of its bed such a glacier presses
with a weight of 486,000 lbs. With a vertical pressure
of this amount the glacier is urged down its valley
by the pressure from behind.” **

Indeed, it is obvious that a glacier many hundred,
or in some cases several thousand, feet in thickness,
must exercise great pressure on the bed over which
it travels. We see this from the striae and grooves

* “Sur l’affouillement glaciaire,” Atti della Soc.Ital. 1863.

** Tyndall, “Conformation of tlie Alps,” Phil. Mag. Oct.

1869.

LAKES.

2 43

on the solid rocks, and the fine mud which is carried
down by glacial streams. It is of quite a different
character from river mud, being soft and impal-
pable, while river mud is comparatively coarse and
gritty.

The diminution in the rapidity of motion of a
glacier at the sides and near the bottom, which has
been relied on as evidence that glaciers cannot
excavate, shows on the contrary how great is the
pressure.

The question has been sometimes discussed as if
the point at issue were whether rivers or glaciers
were the more effective as excavators. But this is
not so.

Even those who consider that lakes are in many
cases due to glaciers might yet admit that rivers
have greater power of erosion. There is, however,
an essential difference in the mode of action. Rivers
tend to regularise their beds; they drain, but cannot
form, lakes. As Playfair long ago pointed out* a lake
is but a temporary condition of a river. Owing in
fact to rivers, lakes are mere temporary incidents.
The tendency of running waters is to cut through
any projection, so that finally its course assumes some

16*

Playfair’s Works, vol. I.

244

SCENERY OF SWITZERLAND.

such curve as that in Fig. 47, from the source to its
entrance into the sea.

The existence of a hard ridge would not give
rise to a Lake, it would delay the excavation of the
valley; above it the slope would become very gentle,
but no actual basin could be formed; we should have
some such section as in Fig. 67. The action of a
glacier is different; it picks out as it were the softer

Fig. 67. — Diagram to illustrate the action of rivers and glaciers.

A, A', Hard ridges; B, B‘, B", Softer strata; C, C, Slope of running
water; D, D, Slope of ice.

places, and under similar circumstances basins might
be formed above the harder ridges as shown in the
dotted lines, D, D.

In many of the Swiss valleys the pressure of the
ice on its bed must have been very great. The
Rhone glacier not only occupied the basin of the
Lake of Geneva, but rose on the Jura to a height of
950 metres. The lake is 309 metres deep, so that
the total thickness of ice must have been over

LAKES.

245

1000 metres. The greatest depth of the lake is
opposite Lausanne, where the thickness of the ice
would be at its maximum.

Moreover, the depth in proportion to its size is
quite insignificant; Fig. 68 shows the height of the
mountains, the thickness of the ice at the time of its
greatest extension, while the dark line below gives
the relative depth of the water, showing that after
9 ZW 2 ?+ 71 + oso

i ' • I

978 060 800

si irr

~n — ru inn ■ w in mi I’M! Illl li 11 Si

Ice,

The Lake

Fig. 68.— Diagram Section along the Lake of Geneva. The dark line
shows the relative depth of the water indicated by the figures above.

all the

Lake of Geneva is really but

a film of

water.

There are, however, strong reasons against re-
garding glaciers as the main agents in the formation of
the great Swiss and Italian lakes. These have been
pointed out with great force by Ball and Bonney, and
Swiss geologists are not generally disposed to accept
the action of glaciers as a sufficient explanation. They
admit that glaciers grind and smoothe the rocks over

246

SCENERY OF SWITZERLAND.

which they pass, but deny that they effectively ex-
cavate.

The Lake of Geneva, 375 metres above the sea,
is over 309 metres deep, and if we allow for the ac-
cumulation of sediment, its real bottom is probably
below the sea level. The Italian Lakes are even
more remarkable. The Lake of Como, 199 metres
above the Sea, is 414 metres deep. Lago Maggiore,
194 metres above the Sea, is no less than 655 metres
deep, so that the bottom is 46 1 metres below the sea
level.

The difficulty thus arising, moreover, is not so
much the absolute depth, as the absence of relative
height above the Sea, so that there would be no suf-
ficient fall to carry off the water.

Even if we suppose that the Sea came up to
Lyons, still the distance from Lausanne being
180 km., the Lake must have been raised 300
metres to give even a minimum fall of 2 per cent.*

In the valley of the Rhone the upper level of the
ice had a slight but regular slope. At Schneestock
the upper limit was at a height of 3550 metres
above the sea, at Leuk 2100, at Morcles near
St. Maurice 1650 metres. But at Chasseron on the
Jura the height is now 1410 metres, at Chasseral

* Forel, Le Leman.

LAKES.

247

1306, on the Saleve 1330. This gives a slope of
2J-2 to 3 per cent only. Now in the present Swiss
glaciers the slope is about 6 per cent. That of the
glacier of the Aar, which is the least inclined, is
5 per cent. No doubt the greater the glaciei the
less is the inclination at which it can move. Still a
slope of 3 per cent would seem quite inadequate.
If, however, we suppose that the Alps had a relative
greater altitude of say 1000 metres the difficulty
would be removed, and the glacier would have a
sufficient fall.

These and other considerations have led gradually
to the opinion that while the valleys occupied by the
Swiss lakes were mainly excavated by running water,
the lakes themselves are due to changes of level
which have raised parts of the valleys as compared
with the river courses nearer the mountains.

Prof. Heim has suggested that the compression
which elevated the Swiss mountains, and piled, as we
have seen {ante, p. q i), more than double the original
weight on this portion of the earth’s surface, led to
the formation of the great lakes. The mountain
mass thus concentrated on a comparatively small
area would from its enormous weight tend to sink
somewhat into the softer magma below, which of
course would have had in this respect the same

248

SCENERY OF SWITZERLAND.

effect as if the surrounding country had risen. The
result would be to dam up the rivers and fill the
valleys. For instance, in the Lake of Lucerne the
bottom of the Bay of Uri is almost fiat; it is evi-
dently a river valley which has been filled with
water.

In fact, speaking generally, the great Swiss lakes
are drowned river valleys.

The relative subsidence of the mountains is no
mere hypothesis.

There are, as we shall see, strong grounds for
believing that the country round Geneva has been
recently raised.

The old river terraces of the Reuss can still be
traced in places along the valley near Zug. Now,
these terraces must have originally sloped from the
upper part downwards, that is to say, from Zug to-
wards Mettmenstetten. But at present the slope is
the other way, i.e. from Mettmenstetten towards Zug.
From this and other evidence we conclude that in
the diiection from Lucerne towards Rappersdorf
there has been an elevation of the land, which has
dammed up the valley, thus turned parts of the Aa
and the Reuss into lakes, and, as we shall see, con-
siderably changed the course of the river.

Again, Professor Heim has pointed out that there

LAKES.

249

has been a comparatively recent elevation, even since
the commencement of the Glacial period, along a line
traversing the Lake of Zurich. This is shown by the
fact, that while the lower terraces follow the general
slope of the valley, the upper glacial deposits present
for some distance a reverse inclination. M. Aeppli
in his recent work* has described them in more
detail. They are seen on both sides of the lake, be-
tween Horgen and Wadenschweil on the one side,
and between Meilen and Stafa on the other. They
do not, however, exactly correspond on the two sides
of the lake, because the zone of compression crosses
the lake diagonally, commencing more to the south
on the east side. For the same reason, while the
compression has on the east side made the terraces
slope towards the lake, on the west the slope is to-
wards the hill. This curious fact was very difficult
to account for, but is satisfactorily explained by the
inversion of the terrace.

I had the great advantage of visiting the terraces
on the west of the lake under the guidance of Pro-
fessor Heim, and looking across we could clearly see
those on the east side also.

Passing to other countries the case of the Dead
Sea is very suggestive. From the lower end a long
* Beitr. z. Geol. K. d. Schw., L. xxxiv.

250

SCENERY OF SWITZERLAND.

depression leads southwards; it is evident that the
Jordan once ran into the Gulf of Akaba and so to
the Red Sea, and that a subsequent change of level
has created the Dead Sea, which has a depth of
396 metres below the Ocean level.

The great American lakes are also probably due
to differences of elevation. Round Lake Ontario, for
instance, there is a raised beach which at the western
end of the lake is no metres above the sea level,
but rises towards the east and north, until near Fine
it reaches an elevation of nearly 300 metres. As
this terrace must have originally been horizontal, we
have here a lake barrier, due to a difference of ele-
vation, amounting to over 180 metres. But though
the lakes may not have been excavated by glaciers
it is probable that the process of filling up would
have made much more progress had they not been
for so long a period occupied by the ice.

The next question which arises is as to the age
of the lakes. The valleys are now regarded by most
Swiss geologists as pre-glacial, but the lakes them-
selves originated after the retreat of the glaciers.*

If these views are correct the larger lakes north
of the Alps may be divided into three classes.

* Penck, Vergletschernng der Deutsche?i Alpen.

LAKES.

251

Firstly, the lakes of the Jura, — those of Neuchatel,
Bienne, and Moral, which occupy synclinal valleys.

Secondly, those of Hallwyl, Baldegger, Sempach,
Greifen, etc., which are moraine lakes, the dams at
the lower ends being moraines.

Thirdly, those of Constance, Zurich, Walen, Zug,
Lucerne, Thun, Brienz, and Geneva, some of which
are indeed partially dammed up by ancient moraines,
but which are partly at least due to the lower ends
of the valleys having risen relatively to the rest.

Dr. F. A. Forel has suggested * that this sub-
sidence of the Central Alps also throws light upon
the former extension of the glaciers. The present
snow-line is at a height of say 2600 metres. If we
assume the subsidence to have been 500 metres
(which seems the minimum), and suppose that 900
metres have been since removed from the whole sur-
face, certainly no exaggerated estimate, this would
bring the snow down to the present line of 600 metres,
which would involve a great extension of the Firn,
and consequently of the glaciers. He considers that
an elevation of 900 metres would bring the glaciers
of the Rhone down again to the Lake of Geneva.
The theory deserves careful study but is open to

* Le Leman.

2 5 2 SCENERY OF SWITZERLAND.

the objection that the Glacial period is no mere local
phenomenon, but seems to have affected the whole
northern hemisphere.

In considering the great Italian lakes which
descend below the sea level, one suggestion has
been that they are the sites of the ends of the
ancient glaciers, and their lower ends are certainly
encircled by gigantic moraines. We must, however,
remember that the valley of the Po is an area of
subsidence and a continuation of the Adriatic, now
partially filled up and converted into land by the
materials brought down from the Alps. Under these
circumstances we are tempted to ask whether the
lower lakes at least may not be the remains of the
ancient Sea which once occupied the whole plain.
Moreover, just as the Seals of Lake Baikal in
Siberia carry us back to the time when that great
sheet of fresh water was in connection with the
Aictic Ocean, so there is in the character of the
launa of the Italian lakes, and especially the pres-
ence of a prawn in the Lake of Garda, some con-
firmation of such an idea.

However this may be, the lower ends of the
lakes have been dammed up by glacial accumula-
tions.

Further evidence, however, is necessary before

LAKES.

253

these interesting questions can be fully and definitely
answered.

The Colour of the Swiss Lakes.

Switzerland owes much of its charm to the lakes,
and the lakes owe their beauty in great measure to
their exquisite colouring. In this respect they differ
considerably: the Lake of Geneva is blue, but most
of the Swiss lakes are more or less green, and
some brownish. What is the reason of these differ-
ences?

The blueness is not due to, though it may be
enhanced by, the reflection of the sky. Pure water
is of an exquisite blue. Of all the Swiss lakes the
Lake of Lucel in the Val d’Herins is perhaps the
clearest, and it is of a lovely blue. Various sugges-
tions have been made to account for the green colour
of some lakes. The most probable explanation appears
to be that suggested by Wettstein, and ably sup-
ported by Forel ,* namely, that the blue is turned
into green by minute quantities of organic matter in
solution. Forel took water from several lakes, and
thoroughly filtered them, but they retained their colour,
showing that it was not due to particles in suspen-
sion. Fie then took a block of peat, and infused it

* Le Leman , vol. II.

254

SCENERY OF SWITZERLAND.

in water, thus obtaining a yellow solution. By adding
a small quantity of this to the blue water of the
Lake of Geneva, he was able to obtain a green
colour, exactly similar to that of the Lake of Lucerne.

He refers as a test case to the sister Lakes of
Achensee and Tegernsee in the Tyrol. The basin
of the Achensee is free from peat, in that of the
Tegernsee peat mosses cover a large space. The
former is a brilliant blue, the latter a lovely green.
He concludes, therefore, with Wettstein, that the
bluest lakes are those which are the purest; while
green lakes contain also a minute quantity of vege-
table matter, or peat, in solution.

This is, however, by no means the only cause to
which water owes a green hue. Shallow water over
yellowish sand is green by the reflection of the yellow
light from the bottom. Again, after storms the water
is often rendered thick and turbid. After the
coarser mud has subsided the finer impalpable
particles give the water a greenish hue, which, how-
ever, is only temporary, though it may last for some
time. Finally, the water is sometimes coloured green
in patches by microscopic algae.

But though the blueness of lakes and seas is not
owing to reflection from the blue sky, the brilliancy,
beauty, and variety of tone and tints, the play of

LAKES.

255

colour to ultramarine and violet, the constant changes
and patterns varying with every breath of wind, in
short the life and glory and beauty of the lakes are
entirely due to the light of the sun.

The Beine or Blancfond.

If, on a fine, still day, we look down the Lake
of Geneva from some neighbouring height, we see
the azure blue of the deep water fringed by a clear
grey or greenish margin. This is the “Beine” or
“Blancfond” where the shallowness of the water
renders visible the grey or yellowish tint of the
bottom. Such a shallow fringe or margin encircles
many of the Swiss lakes, and may be explained as
follows: The waves gradually eat away the bank, giving
rise to a small cliff and talus (Fig. 69 p. 256). Tire
loose stones and sand are gradually rolled down-
wards, forming a slightly inclined terrace (Fig. 69,
K, M) which finally ends in a steep slope. This
terrace is known as the Beine or Blancfond. The
depth of the Beine depends on that to which the
water is agitated by the waves; it is less, therefore,
in sheltered, and greater in exposed, situations. In
the Lake of Geneva it ranges between 1 and 4
metres. It falls into two parts, the inner (K, C) due
to erosion, and the outer (C, M) to deposition. The

Fig. 69. — Diagram of the side of a Lake.

256

SCENERY OF SWITZERLAND.

inclination of the outer slope depends on the nature
of the materials; the finer they are the gentler it is.

structed on the Beine, and this shows us how con-

LAKES.

257

stant the level of the great Swiss lakes must have
been for many centuries or even some thousands of
years. Many of the lake villages belong to the Stone
Age, and the stumps of the piles on which they were
built still remain.

The platforms could not, of course, have been
constructed over water more than at the outside
5 metres in depth, so that during this whole period
the level of the lakes must have been practically
what it is now. Indeed, the structure of the Beine
itself shows that the level must have remained ap-
proximately the same for a very long period.

Scenery of Switzerland. /.

SCENERY OF SWITZERLAND.

253

CHAPTER X.

ON THE INFLUENCE OF THE STRATA UPON SCENERY.

The character of Swiss scenery depends mainly
on denudation and weathering, modified by the
climate, the character, the chemical nature, the
height, and the angle of inclination, of the rocks.

The total thickness of the sedimentary rocks has
been estimated roughly at 200,000* feet, and as the
whole of this was deposited in seas or lakes and was
derived from former continents, we see how enormous
the amount of denudation must have been, especially
if we bear in mind that much of it has been washed
down and deposited, then raised and afterwards
washed down again; some of it moreover several
times.

The principal forces which have disintegrated
rocks are — (1) Water; (2) Changes of temperature;
(3) Chemical actions; (4) Vegetation.

There are few rocks which are not more or less
alterable by, or soluble in, water. It soaks in and

* Many of the beds, however, are not represented in Switzer-

land.

INFLUENCE OF STRATA UPON SCENERY.

259

filters through innumerable crevices, dissolving some
substances, especially when it is charged with car-
bonic acid, and leaving others. It also acts mechan-
ically, for as it expands when freezing, it splits up
even the toughest rocks, if only there are any crevices
into which it can enter. In a dry climate, therefore,
the slopes will generally be steeper than in a more
rainy region. Even in the absence of water, changes
of temperature have a considerable effect owing to
the fractures which they produce by the successive
contractions and expansions to which they give rise.

These, however, though the principal, are by no
means the only factors in denudation. The roots of
plants, for instance, have a considerable effect, in-
sinuating themselves into the smallest crevices and,
as they expand with growth, enlarging them by de-
grees. Yet, on the whole, the action of vegetation
is conservative. It absorbs much of the rainfall,
and the formation of torrents is thus greatly checked.
Some of the French Alpine districts, and much of
Northern Africa, have suffered terribly, and in fact
been reduced almost to deserts, by the reckless de-
struction of forests.

Different kinds of rocks are very differently af-
fected by atmospheric influences.

Siliceous rocks are liable to disintegration by

17*

2 6o

SCENERY OF SWITZERLAND.

weather; but, on the other hand, the separate
grains of sand or quartz are not only insoluble, but
offer great resistance to mechanical action. Water,
especially if charged with carbonic acid, can dissolve
some Silica, but the quantity is insignificant.

Calcareous rocks are much more readily at-
tacked. They often contain some alumina and
siliceous nodules, which remain as a reddish clay
with flints after the calcareous matter has been re-
moved.

Argillaceous rocks cannot be dissolved, but they
are in many cases readily reduced to fine particles
and then easily removed. They generally contain
some calcareous material, and when this is washed
away, pores and hollows are left which let in
moisture. Even when compressed into slates they
often yield to the influence of moisture, and if suf-
ficiently saturated sink into the form of mud.

Along the sides of valleys calcareous rocks often
present steep, even vertical, faces (see ante, Fig. 44,
p. 184, Valley of Bienne). Sandstones and Granite are
generally less bold, and marly beds assume still more
gentle slopes. The behaviour of argillaceous beds is
more dependent on circumstances; if they are fairly
dry they bear themselves well, but if they become
wet they are very perishable.

INFLUENCE OF STRATA UPON SCENERY.

26l

So varied are the conditions that every mountain,
even if the top only is visible, has a character and
individuality of its own.

“Le profil de Phorizon,” says Amiel, “affecte
toutes formes: aiguilles, faites, creneaux, pyramides,
obelisques, dents, crocs, pinces, cornes, coupoles; la
dentelure s’inflechit, se redresse, se tord, s’aiguise
de mille fajons, mais dans le style angulaire des
sierras. Les massifs inferieurs et secondaires pre-
sentent seuls des croupes arrondies des lignes fuyantes
et courbes. Les Alpes ne sont qu’un soulevement, elles
sont un dechirement de la surface terrestre. Le
granit mord le ciel et ne le caresse pas. Le Jura
au contraire fait comme le gros dos sous le dome
bleu.”

Not one of these varied forms is accidental.
Every one of them has its cause and explanation,
though we may not always know what it is.

The same configuration will of course look very
different from different points of view. What seems
like a sharp point is often the end of a ridge. The
sedimentary rocks of the northern Alps (Rigi, Pilatus,
Bauenstock, Sentis, Speer, etc.), often slope up gently
to the summit, and then drop away suddenly in a
steep cliff, frequently broken into a succession of steps
which are rendered conspicuous by lines of snow. They

26 2

SCENERY OF SWITZERLAND.

give therefore what has been happily called by Leslie
Stephen a desk-like form (Fig. 84), presenting broad,
gently inclining plateaux, ending suddenly in a steep,
almost perpendicular, precipice, which towers like a
wall over the valley, such as the Diablerets, Wild-
strubel, Gadmerfluh, Claridenstock, Todi, Vorab,
Balmhorn, Doldenhorn, Bltimlisalp, etc.

In such districts still further denudation gives
rise to ridges terminating in towers and teeth, some-
times of terrific wildness, as in the Engelhorner, or
in the chain of the Gspaltenhorn. The calcareous
Alps are also characterised by the numerous terraces,
bands, pillars, and cornices. The precipices, as for
instance on the Jungfrau and the great Wall of the
Bernese Oberland, sometimes reach 2000 metres.

We might at first be disposed to anticipate that
from their hardness and toughness the Crystalline
rocks would be less liable to denudation than the
calcareous. And in a sense this is true. In con-
sequence however of these very qualities the drainage
in Crystalline districts is mainly superficial, while in
calcareous regions much of the rainfall sinks into the
ground and is carried off by subterranean passages.
In our own country we know that the chalk uplands,
though cut into along the margins by deep combes,
are seldom intersected by valleys, and almost all

INFLUENCE OF STRATA UPON SCENERY. 263

our railway lines leaving London have been com-
pelled to tunnel through the Chalk. So also m
Switzerland the calcareous strata form long con-
tinuous ridges, of which the great wall of the Bernese
Oberland is a marvellous example.

Another reason for the extremely bold character
of the calcareous mountains is that such strata are
extremely stiff, and where argillaceous rocks would
gradually bend, they break away and thus give pre-
cipitous cliffs.

It was at one time supposed that each kind of
rock gave its own special mountain form. Such was
the view, for instance, even of excellent obseivers,
such as L. v. Buch and A. v. Humboldt.

It would, however, be quite a mistake to sup-
pose that particular contours always indicate the
same kind of rock. On the contrary, we find the
same forms in different rocks, and different forms in
the same description of rock. They depend greatly
on the hardness of the rock, and on the angle at
which it stands. Thus tower-like forms occur in
Granite, Amphibolite, Sandstone, Conglomerates,
Hochgebirgskalk, Dolomite, etc. The desk-like form
which is so frequent in calcareous strata (see, for in-
stance, Fig. 70 p. 266, on the right hand side) occurs
also in some districts of Gneiss or of Nagelflue, as, for

264

SCENERY OF SWITZERLAND.

instance, at the Rigi(Fig.84, vol.n. p.55). On the other
hand, the same rock may give a very different land-
scape. Thus Granite often assumes rounded outlines,
but often also gives wild ridges of teeth and needles.’

Gneiss summits with gently inclined beds are
less steep and less pointed, while calcareous rocks if
hard and steeply inclined assume not only wild but
grand outlines. The Eiger is perhaps the finest type
of a calcareous mountain.

On the other hand, in any given district similar
geological structure will generally give similar scenery.

Steeply inclined strata as a rule produce bold
outlines, while those which are more horizontal give
a tamer sceneiy.

Still, where the rocks are very resistent, and de-
nudation has been great, even horizontal strata may
give very bold forms; of this we have a remarkable
instance in the Matterhorn, a mountain left between
two valleys, where the strata are but slightly inclined,
and yet owing to their position and hardness give
us the boldest and steepest mountain of the whole
chain. In districts of the softer rocks we naturally
miss the bold, steep precipices, the jagged ridges
and noble peaks, and must content ourselves with
smiling landscapes and gentle undulations.

INFLUENCE OF STRATA UPON SCENERY.

265

Another reason which affects the landscape in
districts of sedimentary and Crystalline rocks is that
the former crumble away more rapidly, and thus
more quickly lose the rounded surfaces due to ice
action. Thus, as we ascend the valley of the Reuss,
where we leave the softer strata and enter the dis-
trict of Gneiss, we also commence a scenery of knolls
rounded by ice.

In calcareous districts “weather terraces” form a
special feature (Figs. 44, 45 pp. 184,185). They are due
to a succession of rocks of different hardness and tough-
ness, so that some strata weather back more quickly
and take a gentler slope than others. Crystalline
rocks are generally more homogeneous, weather more
evenly, and consequently present more regular and
continuous slopes. The Bristenstock, for instance,
which towers over the Reuss, is a beautiful example.
For a height of 2 500 metres it presents an unbroken
slope at an angle of 36°. Weather terraces are
particularly conspicuous in certain lights, and especially
in winter when there is snow on the gentler slopes.
Even in summer, however, the contrast of vegeta-
tion is often striking, some lines being marked out
by luxuriant grass or bushes, while others are com-
paratively bare. On Granite or Gneiss a good
mountaineer can go almost anywhere, while in moun-

266

SCENERY OF SWITZERLAND.

tains of sedimentary strata he is stopped from time
to time by an impassable precipice.

On the whole, when seen from a distance, the
forms of the sedimentary mountains are more marked,
more broken, and, so to say, more individualised.

The central Crystalline “massives” present very
different forms. The desks, terraces, pinnacles, and
cornices disappear, and we have noble pyramids.
The ridges, moreover, are more jagged and serrated.

Fig. 70.— Ridge of the Gaul!. Profile of the ridge from the Bachlistock
to the Hiibnerstock, showing the peaks of the granite rock and the
desk-like slope of the calcareous strata forming the Huhnerstock.

Fig. 7° shows the contrast of a jagged Crystalline
ridge and the desk-like form of the calcareous strata
on the right (Huhnerstock).

In the splendid panorama seen from Bern the
Crystalline mountain peaks (Finsteraarhorn and Schreck-
horn, Breithorn, Tschingelhorn, etc.) can readily be
distinguished from the calcareous mountains (Blumlis-
alp, Doldenhorn, Aletsch, etc.). The difference of
character is also well seen as we ascend the valley
of the Reuss from Fluellen to Andermatt.

INFLUENCE OF STRATA UPON SCENERY. 267

On the whole, the calcareous chains of the Alps
are wilder, the Crystalline grander.

Typical Gneiss often gives gentle rounded out-
lines. On the other hand, Sericitic Gneiss and Mica
Schists, which often closely resemble Gneiss, show
generally great readiness to fracture in shaip, knife-
edge ridges, and very wild if perhaps less sublime
forms. The Bernese Oberland owes both its great
average height and the variety of its scenery to the
combination of Gneiss with calcareous strata. The
consequence is that it does not form an uniform
range, like the Pyrennees, but a succession of in-
dividual mountains, presenting some of the noblest
forms. In this district the Gneiss is inverted over
the secondary strata, which it thus serves to protect.
The result is that the weathering forms of both strata
come into play, and thus produce endless variety.

Granite is regarded by poets as peculiarly re-
sisting, and it is described as

Stern, unyielding might,

Enduring still through day and night
Rude tempest shock and withering blight.

As a matter of fact, however, granites, as a rule,
are very susceptible of disintegration. Granite moun-
tains tend to gentle, rounded, and massive forms.

Rain, and especially water charged with carbonic

268

SCENERY OF SWITZERLAND.

acid, acts on Granite profoundly. In many quarries
where it looks solid enough it will be found to be
disintegrated to a considerable depth, and even
changed into a loose sand. This is due to the
l'elspar; the alkaline salts of Soda and Potash being
decomposed by the carbonic acid, leaving the Silicate
of Aluminium, the Mica, and the Quartz. It seems
at first inconsistent with this that Granite ridges are
often peculiarly jagged, but in such cases the Granite
is steeply inclined, and the debris are removed as
they form.

In othei cases Granite shows a tendency to weather
in convex, but somewhat flat shells, and to split verti-
cally in two or often three different directions: it is
divided, moreover, into horizontal layers at more or
less regular intervals, thus forming rhomboidal blocks
or pillars. Granite possessing this structure often as-
sumes very bold, wild forms.

Protogine, though so similar to granite, generally
gives a different scenery. It breaks up more readily
into Aiguilles, and the divisional plains are more
marked. The vertically constructed Protogine of
the Mont Blanc range, for instance, has a different
aspect from the chains which are composed of true
granite.

The “Aiguilles” formed by Crystalline Schists,

INFLUENCE OF STRATA UPON SCENERY.

269

as for instance in the Mont Blanc district, at first
sight resemble dolomite peaks. The transverse lines,
however, are not continuous, and the summits are
even more pointed, though in many cases, as, for in-
stance, the Aiguille de Charmoz, what seems a
pointed needle is really a long, narrow crest. The
materials are among the very hardest in existence.

Hornblende schist is sometimes quite pale, some-
times very dark. It often becomes reddish by decay
of the ferrosilicate, so that many mountains of this
rock are known as the Rothhorn, Rothfluh, etc. It
forms bold, sharp ridges, and torn, wild, pointed
peaks.

Porphyry, though rather rare, forms an extensive
bed in the neighbourhood of Botzen, occupying 'an
irregular strip, running from north to south, some
40 miles long by 12 wide, through which the outlet
of the Adige has been cut. The great rounded walls
of dull purplish-red rock, clothed in many places
with brushwood, and supporting large upland plateaux
of the richest herbage, produce a scene of singular
luxuriance and beauty, especially when their tints
are heightened by the glow of the setting sun.
Beautiful as they are at all times, there is then some-
thing almost unearthly in their splendour; and no
one who has not made an evening journey from

270

SCENERY OF SWITZERLAND.

Meran to Botzen, or from the latter place by the
gorge of the Kuntersweg, knows what treasures of
colour the Alps can afford.

Dolomite is a magnesian limestone. The aspect
of Dolomite mountains has been most aptly com-
pared to ruined masonry, and it is often difficult to
believe that the summits of dolomite peaks and
ridges are not crowned by crumbling towers, castles,
and walls built by man.

A square columnar formation is characteristic.
The whole of the face shows transverse and vertical
marking, the transverse lines running more or less
continuously across the whole. “The jagged outlines
of the crests form a principal feature for their re-
cognition. The outline is usually ‘embattled,’ to
borrow an expression from heraldry. The colours are
marvellously beautiful — cream colour and grey pre-
dominate, but not to the exclusion of others. In the
glow of sunset they are almost unearthly.”*

The Upper Jurassic gives valleys a very char-
acteristic aspect. It assumes a steep slope of from
40 0 to 60 °. If the inclination is not above 45 0 it
becomes covered with vegetable soil and often clothed
with fir; but the steeper slopes are bare and arid,
and are known as Chables or ravi£res, giving an
* See Dent, Mountaineering , Badminton Library.

INFLUENCE OF STRATA UPON SCENERY.

271

aspect of ruin and desolation, forming often a strong
contrast with the brilliant vegetation below.

In calcareous districts the surface is sometimes
quite bare and intersected by furrows attaining a
depth of several, sometimes even as much as 30 feet.
Such districts are known as “Lapiees” or “Karren”.
A good illustration is to be seen above the hotel
at Axenstein on the Lake of Lucerne, where a portion
of the rock has been uncovered. Another is at the
Kurhaus on the Brunig. Rollier refers to a great
erratic on the Lapie of Bonjean near Bienne, which
has protected the rock below it, so that it rests on
a flat surface in the middle of the Lapie. The
Hohle Stein near Donanne is another case of the
same kind. The Lapiees or Karren are extremely
barren, but the rock generally contains some small
percentage of clay, which is washed into the hollows
and supports some scanty vegetation.

The Flysch gives gentle uniform slopes. The
Nagelflue, in the familiar case of the Rigi, is an il-
lustration of the desk-like form, with a steep escarp-
ment towards the Bay of Ktissnach and a gentle
slope following the inclination of the beds from the
Rigi Kulm to the Scheidegg. In other cases the
Nagelflue gives a very complicated relief, sometimes
forming mountain knots from which valleys radiate

2 ] 2

SCENERY OF SWITZERLAND.

in all directions. Deep gorges, with perpendicular,
almost overhanging, bellied walls, and abrupt termina-
tions also frequently occur in Nagelflue districts, as
for instance to the north of the Lake of Thun, on
the Speer, and elsewhere.

Glaciated regions present us two totally distinct
types of scenery: a central or upper of bare barren
rock with rounded outlines (Fig. 32 p. 132), and a
peripheral ring of debris in scattered heaps and
long mounds.

These morainic deposits give a peculiar char-
acter to the scenery: the country is diversified
and irregular, thrown into confused heaps and de-
pressions, which, as the lower or ground moraine is
very impervious, often contain small lakes. They
occur especially in well-watered districts, and the
rich network of rivers often take very devious courses.
Desor has happily characterised such a district as
“un paysage morainique.”

The scenery is again affected very much in con-
sequence of the influence of different strata on
streams and springs. For instance, in a country of
hard impervious rock we have numerous little runnels
which gradually unite into larger and larger streams.
On the contrary, in a calcareous district, especially if
fissured, we find, as for instance in parts of the Jura

INFLUENCE OF STRATA UPON SCENERY.

273

and elsewhere, large districts with very few streams,
and here and there copious springs, where the water
is brought to the surface by some more impervious
stratum. A glance at any geological map will show,
for instance, that the districts occupied by the
Upper Jurassic rocks are especially waterless, there
being many square miles without even the smallest
rivulet.

The distribution of springs naturally affects that
of villages. Thus in several of the valleys of the
Jura we find a row of hamlets along the outcrop of
the impervious Purbeck strata.

The influence of different rocks upon vegetation
is another way in which they affect the character
of the scenery. The principal contrast is between
Crystalline and calcareous strata.

Cargneule gives fertile pasturage, as do the Lower
and Middle Jura owing to the quantity of Marl they
contain.

The Cretaceous rocks furnish sweet but not
abundant herbage, and the Lias is but moderately
favourable to vegetation. The Urgonian districts are
arid and barren, and can be distinguished even at a
distance from the Neocomian, which bears a luxuriant
vegetation.

Flysch supports a vegetation, vigorous indeed,

Scenery of Switzerland . /. 1 ^

274

SCENERY OF SWITZERLAND.

bat of comparatively little value; the slopes generally
bear dry grass and heather, while the flat ground is
marshy.

High Alpine plants are often found on moraines,
not so much from any peculiarity of the soil, as be-
cause of its coming from the heights.

Screes are generally bare from the continuous
movement, which does not give plants time to
grow.

Rockfalls.

Falling stones constitute one of the greatest
dangers of the Alps. Tyndall was injured, and
Gerlach killed by one. Many couloirs cannot be
ascended without much risk, and the ancient
passage up Mont Blanc, first discovered by Balmat,
has been abandoned for another longer, but safer,
route. Many of the steeper valley sides, as, for in-
stances, those between Martigny and the Lake of
Geneva, are furrowed by stone streams, which, like
those of water, have their collecting-ground above
their regular channel, and a cone of deposit below,
which, however, stands at a steeper angle than that
of a torrent. Many rock-faces have a continuous talus
or scree of fallen stones at the base, which takes an
angle of about 30°, and in some cases has almost

INFLUENCE OF STRATA UPON SCENERY.

275

climbed up to the summit. Along the valleys of the
Niremont — Pleiades which abut on the Lake of
Geneva at Montreux, the debris from the two sides
meet in the middle, and attain a great thickness.
One of the finest examples is that at the foot of the
Diablerets, which rises from 2035 metres to about
2400 metres.*

The Glarnisch is nearly surrounded by rockfalls
on its northern and eastern sides. They are mostly
of interglacial age, and to one of them the Klon-
thalsee is due.

In the debris of rockfalls the edges of the stones
remain fresh and angular, on many of them the sur-
faces show marks of blows, rubbing, hollows, and
impressions, where they clashed against one another
during the descent. They lie in wild confusion,
large and small together, from fine dust up to rocks
larger than a house. In some cases the originally
loose materials have been subsequently cemented to-
gether into a breccia. The surface is very irregular,
and often contains lakes, as, for instance, at Sierre
in the Valais, and Flims on the Rhine.

The rockfall of Goldau from the Rossberg which

* Renevier, Beitr . z. Geol . K. d. Schw L. xvi.

18*

2j6

SCENERY OF SWITZERLAND.

occurred in 1806, and has been figured by Ruskin,*
is well seen on the St. Gotthard line, between Lucerne
and Brunnen.

Even more destructive was that of Piuro (Plurs)
in the Val Bregaglia in 1618. After heavy rain a
great part of the side of Mont Conto fell suddenly
into the valley, and of 2000 inhabitants very few
escaped.

At Flims (“Ad flumina,” so called from the number
of springs and streams) the road rises far above the
Rhine and passes over an ancient rockfall, the greatest
in all Switzerland, far surpassing that of Goldau. It
blocked up the valley, thus forming a lake, and the
Rhine has not even yet cut completely through it.
The debris rise to a height of 700 metres on both
sides of the river. They consist mainly of Malm
interspersed however with blocks of Dogger, Verru-
cano, etc., and fell from the Flimserstein. The fall
appears to have taken place between the first and
last great extension of the glaciers. As in all rock-
falls the surface is very uneven; and in the hollows
are several beautiful lakes. The isolated eminences
in the valley below Reichenau may be portions of
another rockfall.

* Modern Painters , vol. IV.

INFLUENCE OF STRATA UPON SCENERY. 277

Among other great rockfalls, or perhaps bosses
of the solid rock which have been left by the river,
may be mentioned those of Antrona Piana on the
26th June 1642, which destroyed the Parish Church
and many houses, causing also much loss of life:
those of the Diablerets in 1714 and 1749, of
Montbiel in Prattigau in 1804, of the Dents du
Midi in 1835, and that of Elm in 1881. The pretty
little lake of Chede, on the road between Geneva
and Chamouni, was filled up by a rockfall in the
year 1837.

Nor must rockslips pass altogether unmentioned.
Sometimes the movement is continuous, though very
slow. In the chains of the Gumfluh, between Chateau
D’Oex on the Sarine and the Diablerets, which are
composed of hard calcareous rock on which vegeta-
tion establishes itself with difficulty, the cone of talus
descends slowly towards the valley almost like a
river.*

Again at Soglio in the Val Bregaglia a mass of
detritus which has itself fallen from the steeper pre-
cipices, was for a long time, and probably is still,
slowly moving downwards. The firs which grow on
it do not stand upright, but cross one another at

* Favre and Schardt, Beitr. z. Geol, K. d. Schw., L. XXII.

278

SCENERY OF SWITZERLAND.

various angles, some being almost prostrate. The
rocks below (Gneiss and Mica Schist) are in-
clined so that the edges retard the movement,
which would otherwise be quicker and more
dangerous.

Theobald tells us that in the summer of 1861,
at the time of the melting of the snow, he was on a
geological excursion near the Schwarzhorn in the
Grisons when he gradually became aware of a
strange roaring and crushing noise all round him.
At first he paid little attention to it, but he at
length found that the whole surface on which he
stood was slipping downwards. He escaped as
quickly as he could, but the movement continued,
and about a quarter of an hour afterwards a great
mass, 20 to 30 paces in length, precipitated itself
over a precipice.*

Earth Pyramids.

Whenever we have a deposit of comparatively
loose material with hard blocks, or layers, there is a
tendency to form earth pyramids, owing to the
looser material being here and there protected by
a more or less tabular block of hard substance.

** Beitr. z. Geol. K. d. Schw., L. 11.

INFLUENCE of strata upon scenery. 279

The most remarkable assemblage of such earth
pillars is near Klobenstein, in the valley of the
Katzenbach, near Botzen,* described and figured
by Lyell; those above Viesch, and at Useigne in the
Val d’Herins are other classical examples.

* Prin. of Geol., vol. I.

END OF VOL. I.

PRINTING OFFICE OF THE PUBLISHER.

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