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Full text of "The glaciers of the Alps. Being a narrative of excursions and ascents, an account of the origin and phenomena of glaciers and an exposition of the physical principles to which they are related"

BERKElerN 

LIBRARY 



UNIVERSITY OF 
CALIFORNIA 



EAKTH 

SCIENCES 
LIBRARY 



J 



THE 



GLACIERS OF THE ALPS, 



BEING 

A NARRATIVE OF EXCURSIONS AND ASCENTS, 

AN ACCOUNT OF THE OKIGIN AND PHENOMENA OF GLACIERS, 

AND 

AN EXPOSITION OF THE PHYSICAL PRINCIPLES 
TO WHICH THEY ARE RELATED. 



BY JOHN TYNDALL, F.B.S. 



WITH ILLUSTRATIONS. 



NEW EDITION. 



LONGMANS, GREEN, AND CO. 

LONDON, NEW YORK, AND BOMBAY. 
1896. 



All rights reserved 



EARTH 

SCIENCES 

LIBRARY 



TO 

MICHAEL FAKADAY, 
THIS BOOK 

IS AFFECTIONATELY INSCRIBED. 
1860. 



MS601QO 



PEE FACE. 



IN the following work I have not attempted to mix 
Narrative and Science, believing that the mind once 
interested in the one, cannot with satisfaction pass abruptly 
to the other. The book is therefore divided into Two 
Parts : the first chiefly narrative, and the second chiefly 
scientific. 

In Part I. I have sought to convey some notion of the 
life of an Alpine explorer, and of the means by which his 
knowledge is acquired. In Part II. an attempt is made 
to classify su^h knowledge, and to refer the observed 
phenomena to their physical causes. 

The Second Part of the work is written with a desire to 
interest intelligent persons who may not possess any spe- 
cial scientific culture. For their sakes I have dwelt more 
fully on principles than I should have done in presence of a 
purely scientific audience. The brief sketch of the nature 
of Light and Heat, with which Part II. is commenced, will 
not, I trust, prove uninteresting to the reader for whom it 
is more especially designed. 

Should any obscurity exist as to the meaning of the 



viii PREFACE. 

terms Structure, Dirt-bands, Regelation, Interference, and 
others, which occur in Part I., it will entirely disappear 
in the perusal of Part II. 

Two ascents of Mont Blanc and two of Monte Rosa are 
recorded ; but the aspects of nature, and other circum- 
stances which attracted my attention, were so different 
in the respective cases, that repetition was scarcely 
possible. 

The numerous interesting articles on glaciers which 
have been published during the last eighteen months, and 
the various lively discussions to which the subject has 
given birth, have induced me to make myself better 
acquainted than I had previously been with the historic 
aspect of the question. In some important cases I 
have stated, with the utmost possible brevity, the results 
of my reading, and thus, I trust, contributed to the forma- 
tion of a just estimate of men whose labours in this 
field were long anterior to my own. 

J. T. 

Royal Institution, June, 1860. 



PREFATORY NOTE. 



"GLACIERS of the Alps" was published nearly six and thirty 
years ago, and has been long out of print, its teaching in a 
condensed form having been embodied in the little book 
called " Forms of Water.'* The two books are, however, 
distinct in character ; each appears to me to supplement 
the other ; and as the older work is still frequently asked 
for, I have, at the suggestion of my husband's Publishers, 
consented to the present reprint, which may be followed 
later on by a reprint of " Hours of Exercise." 

Before reproducing a book written so long ago, I 
sought to assure myself that it contained nothing touching 
the views of others which my husband might have wished 
at the present time to alter or omit. With this object I 
asked Lord Kelvin to be good enough to read over for 
me the pages which deal with the history of the subject 
and with discussions in which he himself took an active 
part. In kind response he writes : ' . . . After carefully 
going through all the passages relating to those old differ- 
ences I could not advise the omission of any of them from 
the reprint. There were, no doubt, some keen differences 
of opinion and judgement among us, and other friends 
now gone from us, but I think the statements on contro- 



x PEEFATOKY NOTE. 

versial points in this beautiful and interesting book of your 
husband's are all thoroughly courteous and considerate of 
feelings, and have been felt to be so by those whose views 
were contested or criticised in them." 

The current spelling of Swiss names has changed con- 
siderably since " Glaciers of the Alps " was written, but, 
except in the very few cases where an obvious oversight 
called for correction, the text has been left unaltered. 
Only the Index has been made somewhat fuller than it was. 

L. C. T. 

January, 1896. 



CONTENTS. 

PART I. 

, 1 .INTRODUCTORY. 

Visit to Penrhyn ; the Cleavage of Slate Rocks; Sedgwick's theory its 
difficulties ; Sharpe's observations ; Sorby's experiments ; Lecture at 
the Eoyal Institution ; Glacier Lamination ; arrangement of an expe- 
dition to Switzerland Page 1 

2. EXPEDITION OF 1856 : THE OBERLAND. 

Valley of Lauterbrunnen ; Pliability of rocks ; the Wengern Alp ; the 
Jungfrau and Silberhorn ; Ice avalanches ; Glaciers formed from them ; 
Scene from the Little Scheideck ; the Lower Grind elwald Glacier ; 
the Heisse Platte its Avalanches ; Ice Minarets and Blocks ; Echoes 
of the Wetterhorn ; analogy with the Reflection of Light from angular 
mirrors ; the Reichenbach Cascade ; Handeck Fall ; the Grimsel ; the 
Unteraar Glacier ; hut of M. Dollfuss ; Hotel des Neufchatelois ; the 
Rhone glacier from the Mayenwand ; expedition up the glacier ; 
Coloured Rings round the sun ; crevasses of the n6v& ; extraordinary 
meteorological phenomenon ; Spirit of the Brocken . . . 9 

3. THE TYROL. 

Kaunserthal and the Gebatsch Alp ; Senner or Cheesemakers ; Gebatsch 
Glacier ; a night in a cowshed ; passage to Lantaufer ; a chamois on 
the rocks ; my Guide ; the atmospheric snow-line ; passage of the 
Stelvio ; Colour of fresh snow ; Bormio ; the pass recrossed by night ; 
aspect of the mountains ; Meran to Unserfrau ; passage of the Hock- 
jochtoFend; singular hailstorm; wild glacier region; hidden cre- 
vasses ; First Paper presented to the Royal Society . . . 23 



xii CONTENTS. 

4. EXPEDITION OF 1857 : THE LAKE OF GENEVA. 

Blueness of the water ; the head of the Lake ; appearance of the Rhone ; 
subsidence of particles ; Mirage Page 33 



5. CHAMOUNI AND THE MONTANVERT. 

Arrival ; Coloured Shadows on the snow ; Source of the Arveiron ; fall of 
the Vault ; " Sunrise in the Valley of Chamouni ; " Scratched Rocks ; 
quarters at the Montanvert . . . . . . 37 

6. THE MER DE GLACE. 

Not a Sea but a River of ice ; Wave-forms on its surface ; their explanation ; 
Structure and Strata ; Glacier Tables ; first view of the Dirt Bands ; 
influence of Illumination in rendering them visible ; the Eye in- 
capable of detecting differences between intense lights . . 42 

7. 

Measurements commenced ; the " Cleft Station " at Trelaporte ; Regelation 
of snow granules ; two chamois ; view of the Mer de Glace and its Tri- 
butaries ; Seracs of the Col du Geant ; Sliding and Viscous theories ; 
Rending of the ice ; Striae on its surface ; White Ice-seams . 4G 



Alone upon the glacier ; Lakes and Rivulets ; parallel between Glacier 
and Geological disturbance ; splendid rainbow ; aspect of the glacier 
at the base of the Seracs ; visit to the Chief Guide at Chamouni ; 
Liberties granted . .... . ; . . . . .57 

9. THE JARDIN. 

Glacier du Talef re ; Jardin divides the n6ve ; Blue Veins near the summit ; 
surrounding scene ; Moraines and Avalanches ; Cascade du Talefre ; 
dangers on approaching it from above 61 



10. 

Lightning and Rain ; Spherical hailstones ; an evening among the cre- 
vasses ; Dangerous Leap ; ice-practice ; preparations for an ascent of 
Mont Blanc .... 64 



CONTENTS. xiii 

11. FIRST ASCENT OF MONT BLANC (1857). 

Across the mountain to the Glacier des Bossons; its crevasses ; Ladder left 
behind ; consequent difficulties ; the Grands Mulets ; Twinkling and 
change of Colour of the Stars ; moonlight on the mountains ; start 
with one guide ; difficulties among the crevasses ; the Petit Plateau ; 
Seracs of the Dome du Gouter ; bad condition of snow ; the Grand 
Plateau ; Coloured Spectra round the sun ; the lost Guides ; the Route 
missed ; dangerous ice-slope ; Guide exhausted ; cutting steps ; cheer- 
less prospect ; the Corridor ; the Mur de la Cote ; the Petits Mulets ; 
food and drink disappear ; Physiological experiences on the Calotte ; 
Summit attained ; the Clouds and Mountains ; experiment on Sound ; 
colour of the snow ; the descent ; a solitary prisoner ; second night at 
the Grands Mulets ; Inflammation of eyes ; a blind man among the 
crevasses ; descent to Chamouni ; thunder on Mont Blanc Page 68 



12. 

Life at the Montanvert ; glacier " Blower ; " Cascade of the Talefre ; 
difficulties in setting out lines ; departure from the Montanvert ; my 
hosts ; prospect from the Glacier des Bois ; Edouard Simond . 86 



13. EXPEDITION OF 1858. 

Origin and aim of the expedition ; Laminated Structure of the ice 92 

14. PASSAGE OF THE STRAHLECK. 

Unpromising weather ; appearance of the glacier and of the adjacent 
mountains ; Transverse Protuberances ; Dirt Bands ; Structure ; a Slip 
on a snow slope ; the Finsteraarhorn ; the Schreckhorn ; extraordinary 
Atmospheric Effects ; Summit of the Strahleck ; Grand Amphitheatre ; 
mutations of the clouds ; descent of the rocks ; a Bergschrund ; fog in 
the valley ; descent to the Grimsel 93 



15. 

Ancient Glaciers in the valley of Hasli ; Bounded, Polished, and Striated 
Rocks ; level of the ancient ice ; Groovings on the Grimsel Pass ; glacier 
of the Rhone ; descent of the Rhone valley ; the ^Eggischhorn ; 
Cloud Iridescences ; the Aletsch glacier ; the Marjelen See ; Icebergs ; 
Tributaries of the Aletsch ; Grand glacier-region ; crevasses; a chamois 
deceived , 99 



XIV CONTENTS. 

16. ASCENT OF THE FINSTERAARHORN. 

Character of my Guide ; iridescent cloud ; evening on the Faulberg ; the 
Jungf rau and her neighbours ; a Mountain Cave ; the Jungf rau before 
dawn ; contemplated visit ; the Griinhorn Liicke ; Magnificent Cor- 
ridor ; sunrise ; nev6 of the Viesch glacier ; halt at the base of the 
Finsteraarhorn ; Spurs and Couloirs of the mountain; Pyramidal 
Crest ; scene of Agassiz's observations ; a hard climb ; discipline of 
such an ascent ; Boiling Point ; Registering Thermometer, its fate ; 
daring utterance ; descent by glissades ; the Viesch glacier ; hidden 
crevasses ; a brave and competent guide .... Page 104 



17. 

Subsequent days at the /Eggischhorn ; Afloat on the Icebergs ; Bedding 
and Structure ; Ancient Moraines of the Aletsch ; Scratched Rocks ; 
passage of the mountains to the end of the glacier ; a wild gorge ; 
arrival at Zermatt ; the Rift'elberg 119 

18. FIRST ASCENT OF MONTE ROSA. 

The ascent new to myself and my guide ; directions; Ulrich Lauener ; 
Ominous Clouds ; passage of the Gorner Glacier ; Roches Moutonnees ; 
Avalanche from the Twins ; gradual advance of clouds ; bridged 
chasms ; Scene from a cliff; apparent atmospheric struggle ; Sound of 
the snow ; Dangerous Edge ; Overhanging Cornice ; staff driven 
through it ; increased obscurity ; Rocky Crest ; loss of pocket-book ; 
Summit attained ; Boiling Point ; fall of snow ; exquisite forms of the 
Snow Crystals ; a shower of frozen blossoms ; the descent ; mode of 
attachment ; Startling Avalanche ; Blue Light emitted from the fissures 
of the fresh snow ; Stifling Heat ; return to the Riffel . . 122 

19. 

The Rothe Kumm ; pleasant companions ; difficult descent ; temperatures 
of rock, air, and grass ; Singular Cavern in the ice ; Structure and 
Stratification 133 



20. THE GORNER GRAT AND THE RIFFELHORN ; MAGNETIC 
PHENOMENA. 

Formation and Dissipation of clouds ; Scene from the Gorner Grat ; Mag- 
netism of the Rocks ; the Compass and Sun at variance ; ascent of the 
Riffelhorn ; Magnetic effects ; places of most intense action ; Scratched 



CONTENTS. XV 

and Polished Kocks ; Exfoliation of crust produced by the sliding of 
ancient glaciers ; Magnetic Polarity ; Consequent Points ; Bearings 
from the Biffelhorn ; action on a Distant Needle . . Page 137 



21. 

Fog on the Biffelberg ; its dissipation ; Sunset from the Gorner Grat ; 
Cloud-wreaths on the Matterhorn ; Streamers of Flame ; grand Inter- 
ference Phenomenon ; investigation of Structure ; the Gornerhorn 
glacier ; Western glacier of Monte Eosa ; the Schwarze, Trifti, and 
Theodule glaciers ; welding of the Tributaries to parallel Strips ; 
Temptation 145 



22. SECOND ASCENT OF MONTE ROSA (1858). 

A Light Scrip ; my Guide lent ; a substitute ; a party on the mountain ; 
across the glacier and up the rocks ; the guide expostulates ; among 
the crevasses ; the guide halts ; left alone ; beauty of the mountain ; 
splendid effects of Diffraction ; Cheer from the summit ; on the 
Kamm; climbers meet; among the rocks; Alone on the Summit; 
the Axe slips ; the prospect ; the descent ; serious accident ; a word on 
climbing alone 151 



23. 

The Furgge glacier ; thunder and lightning ; the Weissthor given up ; 
excursion by Stalden to Saas ; Herr Imseng ; the Mattmark See and 
Hotel ; ascent of a boulder ; Snow-storm ; cold quarters ; the Monte 
Moro ; the Allalein glacier ; a noble vault ; Structure and Dirt-bands ; 
stormy weather ; Avalanches at Saas ; the Fee glacier ; Frozen dust 
on the Mischabelhorner ; Snow, Vapour, and Cloud; curious effect on 
the hearing ; " a Terrible Hole ; " singular group ; a Song from ' The 
Bobbers ' . 160 



24. 

Need of observations on Alpine Temperature ; Balmat's intention ; aid 
from the Boyal Society; Difficulties at Chamouni in 1858; the In- 
tendant memorialised ; his response ; the Seracs revisited ; Crevasses 
and Crumples ; bad weather ; thermometers placed at the Jardin ; 
Avalanches of the Talefre ; wondrous sky .... 168 



xvi CONTENTS. 

25. SECOND ASCENT OF MONT BLANC (1858). 

Shadows of the Aiguilles ; Silver Trees at sunrise ; M. Necker's letter ; 
Birds as Sparks and Stars against the sky ; crevasse bridged ; ladder 
rejected ; a hunt for a pont ; crevasses crossed ; Magnificent Sunset ; 
illuminated clouds ; Storm on the Grands Mulcts ; a Comet discovered ; 
start by starlight ; the Petit Plateau a reservoir for avalanches ; Bal- 
mat'a warning ; the Grand Plateau at dawn ; blue of the ice ; Balmat 
in danger ; Clouds upon the Calotte ; the Summit ; wind and snow- 
dust ; Balmat frostbitten ; halt on the Calotte ; descent to Chamouni ; 
good conduct of porters Page 177 



26. 

Hostility of Chief Guide ; Proces Verbal ; the British Association ; appli- 
cation to the Sardinian authorities ; President's Letter ; Koyal Society; 
Testimonial to Balmat . 192 



27. WINTER EXPEDITION TO THE MER DE GLACE, 1859. 

First defeat and fresh attempt ; Geneva to Chamouni ; deep snow ; Deso- 
lation ; slow progress ; a horse in the snow ; a struggle ; Chamouni on 
Christmas night ; mountains hidden ; Climb to the Montanvert ; Snow 
on the Pines ; debris of avalanches ; Breaking of snow ; Atmospheric 
Changes; the mountains concealed and revealed ; colour of the snow ; 
the Montanvert in Winter ; footprints in the snow ; wonderful frost 
figures ; Crystal Curtain ; the Mer de Glace in Winter ; the first night ; 
" arose of dawn; " Crimson Banners of the Aiguilles ; the stakes fixed; 
a Hurricane on the glacier ; the second night ; Wild Snow-storm ; a 
man in a crevasse ; calm ; Magnificent Snow Crystals ; Sound through 
the falling snow; swift descent ; Source of the Arveiron ; Crystal Cave ; 
appearance of water ; westward from the vault ; Majestic Scene; Fare- 
well . 195 



CONTENTS. xvii 



PART II. 



1. LIGHT AND HEAT. 

What is Light ? notion of the ancients ; requires Time to pass through 
Space ; Komer, Bradley, Fizeau ; Emission Theory supported by New- 
ton, opposed by Huyghens ; the Wave Theory established by Young 
and Fresnel ; Theory explained ; nature of Sound ; of Music ; of Pitch ; 
nature of Light ; of Colour ; two sounds may produce silence ; two rays 
of light may produce darkness ; two rays of heat may produce cold ; 
Length and Number of waves of light ; Liquid Waves ; Interference ; 
Diffraction ; Colours of Thin Plates ; applications of the foregoing to 
cloud iridescences, luminous trees, twinkling of stars, the Spirit of the 
Brocken, &c Page 223 

2. RADIANT HEAT. 

The Sun emits a multitude of Non -luminous Eays ; Kays of Heat differ 
from rays of Light as one colour differs from another ; the same ray 
may produce the sensations of light and heat . . . .39 

3. QUALITIES OF HEAT. 

Heat a kind of Motion; system of exchanges ; Luminous and Obscure Heat; 
Absorption by Gases ; gases may be transparent to light, but opaque 
to heat ; Heat selected from luminous sources ; the Atmosphere acts 
the part of a Eatchet-wheel ; possible heat of a Distant Planet ; causes 
of Cold in the upper strata of the Earth's Atmosphere . . 241 

4. ORIGIN OF GLACIERS. 

Application of principles ; the Snow-line ; its meaning ; waters piled annu- 
ally in a solid form on the summits of the hills ; the Glaciers furnish 
the chief means of escape ; superior and inferior snow-line . 248 



o. 

.Whiteness of snow ; whiteness of ice ; Bound air-bubbles ; melting and 
freezing ; Conversion of snow into ice by Pressure . . . 249 

a 



xviii CONTENTS. 

6. COLOUR OF WATER AND ICE. 

Waves of Ether not entangled ; they are separated in the prism ; they are 
differently absorbed ; Colour due to this ; Water and Ice blue ; water 
and ice opaque to radiant heat ; Long Waves shivered on the mole- 
cules ; Experiment ; Grotto of Capri ; theLaugs of Iceland Page 253 

7. COLOURS OF THE SKY. 

Newton's idea ; Goethe's Theory ; Clausius and Briicke ; Suspended 
Particles ; singular effect on a painting explained by Goethe ; Light 
separated without Absorption ; Keflected and Transmitted light ; 
blueness of milk and juices; the Sun through London smoke; 
Experiments; Blue of the Eye; Colours of Steam; the Lake of 
Geneva . 257 



8. THE MORAINES. 

Glacier loaded along its edges by the ruins of the mountains ; Lateral 
Moraines ; Medial Moraines ; their number one less than the number 
of Tributaries ; Moraines of the Mer de Glace ; successive shrinkings ; 
Glacier Tables explained ; ' Dip ' of stones upon the glacier enables 
us to draw the Meridian Line ; type ' Table ; ' Sand Cones ; moraines 
engulfed and disgorged ; transparency of ice under the moraines 263 



9 . GLACIER MOTION, PRELIMINARY. 

Neve and Glacier; First Measurements; HugiandAgassiz; Escher's defeat 
on the Aletsch ; Piles fixed across the Aar glacier by Agassiz in 1841 ; 
Professor Forbes invited by M. Agassiz ; Forbes's first observations on 
the Mer de Glace in 1842 ; motion of Agassiz 's piles measured by M. 
Wild ; Centre of the glacier moves quickest ; State of the Question 2G9 



10. MOTION OF THE MER DE GLACE. 

The Theodolite ; mode of measurement ; first line ; Centre Point not the 
quickest ; second line : former result confirmed ; Law of Motion sought ; 
the glacier moves through a Sinuous Valley ; effect of Flexure; Western 
half of glacier moves quickest ; Point of Maximum Motion crosses axis ; 



CONTENTS. xix 

Eastern half moves quickest; Locus of Point of Maximum Motion ; New 
Law ; Motion of the Geant ; motion of the Lechaud ; Squeezing of the 
Tributaries through the Neck of the valley at Trelaporte ; the Lechaud 
a Driblet . ... Page 275 

11. ICE WALL AT THE TACUL, VELOCITIES OF TOP 
AND BOTTOM. 

First attempt by Mr. Hirst; second attempt, stakes fixed at Top, Bottom, 
and Centre ; dense fog ; the stakes lost ; process repeated ; Velocities 
determined .... , 289 



12. WINTER MOTION OF THE MER DE GLACE. 

First line, Above the Montanvert ; second line, Below the Montanvert ; 
Eatio of winter to summer motion 294 



13. CAUSE OF GLACIER MOTION, DE SAUSS ORE'S 
THEORY. 

First attempt at a Theory by Scheuchzer in 1705 ; Charpentier's theory, or 
the Theory of Dilatation ; Agassiz's theory ; Altmann and Griiner ; 
theory of De Saussure, or the Sliding Theory ; in part true ; strained 
interpretation of this theory 296 

14. RENDU'S THEORY. 

Character of Kendu; his Essay entitled ' Theorie des Glaciers de la 
Savoie; ' extracts from the essay; he ascribes "circulation" to natural 
forces; classifies glaciers; assigns the cause of the conversion of 
snow into ice; notices Veined Structure; "time and affinity;" 
notices Kegelation ; diminution of glaciers reservoirs ; Kemarkable 
Passage ; announces Swifter Motion of Centre ; North British Keview ; 
Discrepancies explained by Eendu ; Liquid Motion ascribed to glacier ; 
all the phenomena of a Eiver reproduced upon the Mer de Glace ; Eatio 
of Side and Central velocities ; Errors removed . . . 299 



15. 

Anticipations of Eendu confirmed by Agassiz and Forbes; analogies 
with Liquid Motion established by Forbes ; his Measurements in 1842 ; 
measurements in 1844 and 1846 ; Measurements of Agassiz and Wild 



XX CONTENTS. 

in 1842, 1843, 1844, and 1845 ; Agassiz notices the " migration " of the 
Point of Swiftest Motion ; true meaning of this observation ; Summary 
of contributions on this part of the question . . . Page 308 

16. FORBES'S THEORY. 

Discussions as to its meaning ; Facts and Principles ; definition of theory ; 
Some Experiments on the Mer de Glace to test the Viscosity of the 
Ice .311 

17. THE CREVASSES. 

Caused by the Motion ; Ice Sculpture ; Fantastic Figures ; beauty of the 
crevasses of the highest glaciers ; Birth of a crevasse ; Mechanical 
Origin ; line of greatest strain ; Marginal Crevasses ; Transverse Cre- 
rasses ; Longitudinal Crevasses ; Bergschrunds ; Influence of Flexure ; 
why the Convex Sides of glaciers are most crevassed . . 315 

18. 

Further considerations on Viscosity ; Numerical Test ; formation of cre- 
vasses opposed to viscosity 325 

19. HEAT AND WORK. 

Connexion of Natural Forces ; Equivalence of Heat and Work ; heat 
produced by Mechanical Action ; heat consumed in producing work ; 
Chemical Attractions ; Attraction of Gravitation ; amount of heat 
which would be produced by the stoppage of the Earth in its Orbit ; 
amount produced by the falling of the Earth into the Sun ; shifting of 
Atoms ; heat consumed in Molecular Work ; Specific Heat ; Latent 
Heat; 'friability' of ice near its melting point; Kotten Ice and 
softened Wax . .... . . . . . 328 

20. 

Papers presented to the Koyal Society by Prof essor Forbes in 1846 ; Capil- 
lary Hypothesis of glacier motion ; hypothesis examined . . 334 

21. THOMSON'S THEORY. 

Statement of theory; influence of Pressure on the Melting Point of 
Ice ; difficulties of theory ; Calculation of requisite Pressure ; Actual 
pressure insufficient 340 



CONTENTS. xxi 

22. PRESSURE THEORY. 

Pressure and Tension ; possible experiments ; Ice may be moulded into 
Vases and Statuettes or coiled into Knots ; this no proof of Viscosity ; 
Actual Experiments ; a sphere of ice moulded to a lens ; a lens moulded 
to a cylinder ; a lump of ice moulded to a cup ; straight bars of ice 
bent ; ice thus moulded incapable of being sensibly stretched ; when 
Tension is substituted for Pressure, analogy with viscous body breaks 
down . . . . ..... . . Page 346 

23. REGELATION. 

Faraday's first experiments ; Freezing together of pieces of ice at 32 ; 
Freezing in Hot Water ; Faraday's recent experiments ; Kegelation not 
due to Pressure nor to Capillary Attraction ; it takes place in vacuo ; 
fracture and regelation ; no viscidity discovered . . .351 

24. CRYSTALLIZATION AND INTERNAL LIQUEFACTION. 

How crystals are 'nursed;' Snow-Crystals; Crystal Stars formed in 
Water ; Arrangement of Atoms of Lake Ice ; dissection of ice by a 
sunbeam ; Liquid Flowers formed in ice ; associated Vacuous Spots ; 
curious sounds ; their explanation ; Cohesion of water when free from 
air ; liquid snaps like a broken spring ; Ebullition converted into 
Explosion ; noise of crepitation ; Water-cells in glacier ice ; Vacuous 
Spots mistaken for Bubbles ; not Flattened by Pressure ; experiments ; 
Cause of Kegelation 353 

25. THE MOULINS. 

Their character ; Depth of Moulin on Grindelwald Glacier ; Explanation 
the Grand Moulin of the Mer de Glace ; Motion of moulins . 362 

26. DIRT-BANDS OF THE MER DE GLACE. 

Their discovery by Professor Forbes ; view of Bands from a point near the 
F16gere ; Bands as seen from Les Charmoz ; Skew Surface of glacier ; 
aspect of Bands from the Cleft Station ; Origin of bands ; tendency to 
become straight ; differences between Observers . . 367 

27. VEINED STRUCTURE OF GLACIERS. 

General appearance ; Grooves upon the glacier ; first observations ; de- 
scription by M. Guyot ; observations of Professor Forbes ; Structure 



xxii CONTENTS. 

and Stratification ; subject examined ; Marginal Structure ; Transverse 
Structure ; Longitudinal Structure ; experimental illustrations ; the 
Structure Complementary to the Crevasses ; glaciers of the Oberland, 
Valais, and Savoy examined with reference to this question Page 376 

28. THE VEINED STRUCTURE AND DIFFERENTIAL MOTION. 

Marginal Structure Oblique to sides ; Drag towards the centre ; diffi- 
culties of theory which ascribes the structure to Differential Sliding ; 
it persists across the lines of maximum sliding . . . 395 

29. THE RIPPLE THEORY OF THE VEINED STRUCTURE. 

Hippies in Water supposed to correspond to Glacier Structure ; analysis 
of theory ; observation of the MM. Weber ; water dropping from an 
4 oar ; stream cleft by an obstacle ; Two Divergent lines of Eipple ; 
Single Line produced by Lateral Obstacle ; Direction of ripples com- 
pounded of Eiver's motion and Wave motion ; Structure and Eipples 
due to different causes ; their positions also different . . 398 

30. THE VEINED STRUCTURE AND PRESSURE. 

Supposed case of pressed prism of glass ; Experiments of Nature ; Quartz- 
pebbles flattened and indented ; Pressure would produce Lamination ; 
Tangential Action 404 



31. THE VEINED STRUCTURE AND THE LIQUEFACTION OF 
ICE BY PRESSURE. 

Influence of pressure on Melting and Boiling points ; some substances 
swell, others shrink in melting ; effects of pressure different on the two 
classes of bodies ; Theoretic Anticipation by Mr. James Thomson ; 
Melting point of Ice lowered by pressure ; Internal Liquefaction of a 
prism of solid ice by pressure ; Liquefaction in Layers ; appplication to 
the Veined Structure 408 

32. WHITE ICE-SEAMS OF THE GLACIER DU GEANT. 

Aspect of Seams ; they sweep across the glacier concentric with Struc- 
ture ; Structure at the base of the Talefre cascade ; Crumples ; Scaling 
off by pressure ; Origin of seams of White Ice . . . 413 



CONTENTS. xxiii 

33. 

Glacier du Geant in a state of Longitudinal Compression ; Measurements 
which prove that its hinder parts are advancing upon those in front ; 
Shortening of its Undulations ; Squeezing of white Ice-seams ; develop- 
ment of Veined Structure Page 419 

SUMMARY . . . . . . . .422 

APPENDIX 427 

INDEX . 441 



ILLUSTRATIONS. 



The Mer de Glace. Showing the Cleft Station at Trelaporte, the 
Echelets, the Tacul, the Periades, and the Grand Jorasse. Frontispiece 

Fig. Page 

1. Ice Minaret .... . ... 14 

2. Diagram of an angular reflector . 16 

4 " i Boats' sails inverted by Atmospheric Refraction ... 35 

5. Wave-like forms on the Mer de Glace . . . . . . 43 

6. Glacier Table . . . . . . . . . . .44 

7. Tributaries of the Mer de Glace ........ 53 

8. Magnetic Boulder of the Riffelhorn . . ... . .143 

jj' r Luminous Trees projected against the sky at sunrise 180, 181 

12j 

13. Snow on the Pines . 201 



Snow Crystals 214 

16. Chasing produced by waves . . . . * . . . . 233 

17. Diagram explanatory of Interference 234 

18. Interference Spectra, produced by Diffraction . . To face 235 

19. Moraines of the. Mer de Glace .... . 264 

20. Typical section of a glacier Table ... * . . 266 

21. Locus of the Point of Maximum Motion 286 

22. Inclinations of ice cascade of the Glacier des Bois . . . 313 

23. Inclinations of Mer de Glace above 1'Angle ... 314 

24. Fantastic Mass of ice 316 

25. Diagram explanatory of the mechanical origin of Crevasses . 318 
20. Diagram showing the line of Greatest Strain .... 319 

27 A. ] Section and Plan of a portion of the Lower Grindelwald 

27B. f Glacier , . 322 



XXVI ILLUSTRATIONS. 

Fig. Page 

28. Diagram illustrating the crevassing of Convex Sides of glacier 323 

29. Diagram illustrating test of viscosity 326 

30.^ 

01 f 

32 ' r Moulds used in experiments with ice . . . . 346-348 
33.) 

34. Liquid Flowers in lake ice . . . . . . . 355 

35. Dirt-bands of the Mer de Glace, as seen from a point near the 

Flegere . . . ... V . .To face 367 

36. Ditto, as seen from les Charmoz . .-.- *, . 368 

37. Ditto, as seen from the Cleft Station, Trelaporte . . 369 

38. Plan of Dirt-bands taken from Johnson's ' Physical Atlas ' . 374 

39. Veined Structure on the walls of crevasses .... 381 

40. Figure explanatory of the Marginal Structure . ... 383 

41. Plan of part of icefall, and of glacier below it (Glacier of the 

Ehone) . . 386 

42. Section of ditto . . . . ... . . . 386 

43. Figure explanatory of Longitudinal Structure .... 388 

44. Structure and bedding on the Great Aletsch Glacier . . . 391 

4g | Structure and Stratification on the Furgge glacier . . 394 

47. Diagram illustrating Differential Motion . . . , . . 395 

A C\ ~\ 

4Q I Diagrams explanatory of the formation of Eipples . 400, 403 

59" j Appearance of a prism of ice partially liquefied by Pressure . 410 

5?" 1 Figures illustrative of compression and liquefaction of ice . 411 

oo. J < 

^:' i Sections of White Ice-seams . . . . ' . . . 414 
oo. J 

5S* } Variations in the Dip of the Veined Structure . . 414, 415 

58. Section of three glacier Crumples 416 

59. Wall of a crevasse, with incipient crumpling . ... 416 

60. Plan of a Stream on the Glacier du Geant . . ... 418 

61. Plan of a Seam of White Ice on ditto ... . . 418 



PART I. 

CHIEFLY NAKKATIVE, 



Ages are your days, 

Ye grand expressors of the present tense 

And types of permanence ; 

Firm ensigns of the fatal Being 

Amid these coward shapes of joy and grief 

That will not bide the seeing. 

Hither we bring 

Our insect miseries to the rocks, 

And the whole flight with pestering wing 

Vanish and end their murmuring, 

Vanish beside these dedicated blocks. 

EMEBSON 



GLACIEES OF THE ALPS. 

INTRODUCTORY. 

(I-) 

IN the autumn of 1854 I attended the meeting of the 
British Association at Liverpool ; and, alter it was over, 
availed myself of my position to make an excursion into 
North Wales. Guided by a friend who knew the country, 
I became acquainted with its chief beauties, and concluded 
the expedition by a visit to Bangor and the neighbouring 
slate quarries of Penrhyn. 

From my boyhood I had been accustomed to handle 
slates ; had seen them used as roofing materials, and had 
worked the usual amount of arithmetic upon them at 
school ; but now, as I saw the rocks blasted, the broken 
masses removed to the sheds surrounding the quarry, and 
there cloven into thin plates, a new interest was excited, 
and I could not help asking after the cause of this extra- 
ordinary property of cleavage. It sufficed to strike the 
point of an iron instrument into the edge of a plate of rock 
to cause the mass to yield and open, as wood opens in 
advance of a wedge driven into it. I walked round the 
quarry and observed that the planes of cleavage were 
everywhere parallel ; the rock was capable of being split 
in one direction only, and this direction remained perfectly 
constant throughout the entire quarry. 

I was puzzled, and, on expressing my perplexity to my 
companion, he suggested that the cleavage was nothing 



2 CLEAVAGE OF SLATE ROCKS. 

more than the layers in which the rock had been origin- 
ally deposited, and which, by some subsequent disturbance, 
had been set on end, like the strata of the sandstone rocks 
and chalk cliffs of Alum Bay. But though I was too igno- 
rant to combat this notion successfully, it by no means 
satisfied me. I did not know that at the time of my visit 
this very question of slaty cleavage was exciting the 
greatest attention among English geologists, and I quitted 
the place with that feeling of intellectual discontent which, 
however unpleasant it may be for a time, is very useful as 
a stimulant, and perhaps as necessary to the true appre- 
ciation of knowledge as a healthy appetite is to the enjoy- 
ment of food. 

On inquiry I found that the subject had been treated 
by three English writers, Professor Sedgwick, Mr. Daniel 
Sharpe, and Mr. Sorby. From Professor Sedgwick I 
learned that cleavage and stratification were things totally 
distinct from each other ; that in many cases the strata 
could be observed with the cleavage passing through them 
at a high angle ; and that this was the case throughout vast 
areas in North Wales and Cumberland. I read the lucid 
and important memoir of this eminent geologist with great 
interest : it placed the data of the problem before me, as 
far as they were then known, and I found myself, to some 
extent at least, in a condition to appreciate the value of a 
theoretic explanation. 

Everybody has heard of the force of gravitation, and of 
that of cohesion ; but there is a more subtle play of forces 
exerted by the molecules of bodies upon each other when 
these molecules possess sufficient freedom of action. In 
virtue of such forces, the ultimate particles of matter are 
enabled to build themselves up into those wondrous edifices 
which we call crystals. A diamond is a crystal self-erected 
from atoms of carbon ; an amethyst is a crystal built up 
from particles of silica ; Iceland spar is a crystal built 



CRYSTALLIZATION THEORY. 3 

by particles of carbonate of lime. By artificial means we 
can allow the particles of bodies the free play necessary to 
their crystallization. Thus a solution of saltpetre exposed 
to slow evaporation produces crystals of saltpetre ; alum 
crystals of great size and beauty may be obtained in a 
similar manner ; and in the formation of a bit of common 
sugar-candy there are agencies at play, the contemplation 
of which, as mere objects of thought, is sufficient to make 
the wisest philosopher bow down in wonder, and confess 
himself a child. 

The particles of certain crystalline bodies are found to 
arrange themselves in layers, like courses of atomic ma- 
sonry, and along these layers such crystals may be easily 
cloven into the thinnest laminae. Some crystals possess 
one such direction in which they may be cloven, some 
several ; some, on the other hand, may be split with dif- 
ferent facility in different directions. Rock salt may be 
cloven with equal facility in three directions at right angles 
to each other ; that is, it may be split into cubes ; calcspar 
may be cloven in three directions oblique to each other ; 
that is, into rhomboids. Heavy spar may also be cloven 
in three directions, but one cleavage is much more perfect, 
or more eminent as it is sometimes called, than the rest. 
Mica is a crystal which cleaves very readily in one di- 
rection, and it is sufficiently tough to furnish films of ex- 
treme tenuity : finally, any boy, with sufficient skill, who 
tries a good crystal of sugar-candy in various directions 
with the blade of his penknife, will find that it possesses 
one direction in particular, along which, if the blade of the 
knife be placed and struck, the crystal will split into 
plates possessing clean and shining surfaces of cleavage. 

Professor Sedgwick was intimately acquainted with all 
these facts, and a great many, more, when he investigated 
the cleavage of slate rocks ; and seeing no other expla- 
nation open to him, he ascribed to slaty cleavage a crystal- 

B 2 



4 POLAR FOECES. 

line origin. He supposed that the particles of slate rock 
were acted on, after their deposition, by " polar forces," which 
so arranged them as to produce the cleavage. According 
to this theory, therefore, Honister Crag and the cliffs of 
Penrhyn are to be regarded as portions of enormous 
crystals ; a length of time commensurate with the vast- 
ness of the supposed action being assumed to have elapsed 
between the deposition of the rock and its final crystal- 
lization. 

When, however, we look closely into this bold and beau- 
tiful hypothesis, we find that the only analogy which exists 
between the physical structure of slate rocks and of crystals 
is this single one of cleavage. Such a coincidence might 
fairly give rise to the conjecture that both were due to 
a common cause ; but there is great difficulty in accepting 
this as a theoretic truth. When we examine the structure 
of a slate rock, we find that the substance is composed of 
the debris of former rocks ; that it was once a fine mud, 
composed of particles of sensible magnitude. Is it meant 
that these particles, each taken as a whole, were re-arranged 
after deposition ? If so, the force which effected such an 
arrangement must be wholly different from that of crystalli- 
zation, for the latter is essentially molecular. What is this 
force ? Nature, as far as we know, furnishes none com- 
petent, under the conditions, to produce the effect. Is it 
meant that the molecules composing these sensible particles 
have re-arranged themselves ? We find no evidence of 
such an action in the individual fragments : the mica is 
still mica, and possesses all the properties of mica ; and so 
of the other ingredients of which the rock is composed. 
Independent of this, that an aggregate of heterogeneous 
mineral fragments should, without any assignable external 
cause, so shift its molecules % as to produce a plane of 
cleavage common to them all, is, in my opinion, an 
assumption too heavy for any theory to bear. 



MECHANICAL THEOKY. 5 

Nevertheless, the paper of Professor Sedgwick invested 
the subject of slaty cleavage with an interest not to be 
forgotten, and proved the stimulus to further inquiry. 
The structure of slate rocks was more closely examined ; 
the fossils which they contained were subjected to rigid 
scrutiny, and their shapes compared with those of the same 
species taken from other rocks. Thus proceeding, the late 
Mr. Daniel Sharpe found that the fossils contained in slate 
rocks are distorted in shape, being uniformly flattened out 
in the direction of the planes of cleavage. Here, then, was 
a fact of capital importance, the shells became the indi- 
cators of an action to which the mass containing them had 
been subjected ; they demonstrated the operation of pres- 
sure acting at right angles to the planes of cleavage. 

The more the subject was investigated, the more clearly 
were the evidences of pressure made out. Subsequent to 
Mr. Sharpe, Mr. Sorby entered upon this field of inquiry. 
With great skill and patience he prepared sections of slate 
rock, which he submitted to microscopic examination, and 
his observations showed that the evidences of pressure could 
be plainly traced, even in his minute specimens. The sub- 
ject has been since ably followed up by Professors Haughton, 
Harkness, and others ; but to the two gentlemen first 
mentioned we are, I think, indebted for the prime facts on 
which rests the mechanical theory of slaty cleavage.* 

The observations just referred to showed the co-existence 
of the two phenomena, but they did not prove that pressure 
and cleavage stood to each other in the relation of cause 
and effect. " Can the pressure produce the cleavage ? " 
was still an open question, and it was one which mere rea- 
soning, unaided by experiment, was incompetent to answer. 

* Mr. Sorby has drawn my attention to an able and interesting paper 
by M. Bauer, in Karsten's ' Archiv ' for 1846 ; in which it is announced 
that cleavage is a tension of the mass produced by pressure. The author 
refers to the experiments of Mr. Hopkins as bearing upon the question. 



6 LECTUKE AT THE BOYAL INSTITUTION 

Sharpe despaired of an experimental solution, regarding 
our means as inadequate, and our time on earth too short 
to produce the result. Mr. Sorby was more hopeful. Sub- 
mitting mixtures of gypsum and oxide of iron scales to 
pressure, he found that the scales set themselves approxi- 
mately at right angles to the direction in which the pres- 
sure was applied. The position of the scales resembled 
that of the plates of mica which his researches had dis- 
closed to him in slate rock, and he inferred that the pre- 
sence of such plates, and of flat or elongated fragments 
generally, lying all in the same general direction, was the 
cause of slaty cleavage. At the meeting of the British 
Association at Glasgow, in 1855, I had the pleasure of 
seeing some of Mr. Sorby 's specimens, and, though the 
cleavage they exhibited was very rough, still, the tendency 
to yield at right angles to the direction in which the pres- 
sure had been applied, appeared sufficiently manifest. 

At the time now referred to I was engaged, and had 
been for a long time previously, in examining the effects 
of pressure upon the magnetic force, and, as far back as 
1851, I had noticed that some of the bodies which I had 
subjected to pressure exhibited a cleavage of surpassing 
beauty and delicacy. The bearing of such facts upon 
the present question now forcibly occurred to me. I fol- 
lowed up the observations ; visited slate yards and quarries, 
observed the exfoliation of rails, the fibres of iron, the struc- 
ture of tiles, pottery, and cheese, and had several practical 
lessons in the manufacture of puff-paste and other lami- 
nated confectionery. My observations, I thought, pointed 
to a theory of slaty cleavage different from any previously 
given, and which, moreover, referred a great number of 
apparently unrelated phenomena to a common cause. On 
the 10th of June, 1856, I made them the subject of a 
Friday evening's discourse at the Eoyal Institution.* 
* See Appendix. 



OKIGIN OF KESEAKCHES. 7 

Such are the circumstances, apparently remote enough, 
under which my connexion with glaciers originated. My 
friend Professor Huxley was present at the lecture re- 
ferred to : he was well acquainted with the work of Pro- 
fessor Forbes, entitled ' Travels in ^ the Alps,' and he 
surmised that the question of slaty cleavage, in its new 
aspect, might have some bearing upon the laminated struc- 
ture of glacier-ice discussed in the work referred to. He 
therefore urged me to read the i Travels,' which I did with 
care, and the book made the same impression upon me 
that it had produced upon my friend. We were both 
going to Switzerland that year, and it required but a slight 
modification of our plans to arrange a joint excursion over 
some of the glaciers of the Oberland, and thus afford our- 
selves the means of observing together the veined structure 
of the ice. 

Had the results of this arrangement been revealed to me 
beforehand, I should have paused before entering upon an 
investigation which required of me so Jong a renunciation 
of my old and more favourite pursuits. But no man knows 
when he commences the examination of a physical problem 
into what new and complicated mental alliances it may 
lead him. No fragment of nature can be studied alone ; 
each part is related to every other part ; and hence it is, 
that, following up the links of law which connect pheno- 
mena, the physical investigator often finds himself led far 
beyond the scope of his original intentions, the danger in 
this respect augmenting in direct proportion to the wish of 
the inquirer to render his knowledge solid and complete. 

When the idea of writing this book first occurred to me, 
it was not my intention to confine myself to the glaciers 
alone, but to make the work a vehicle for the familiar ex- 
planation of such general physical phenomena as had come 
under my notice. Nor did I intend to address it to a cul- 
tured man of science, but to a youth of average intelligence, 



8 A BOY'S BOOK. 

and furnished with the education which England now offers 
to the young. I wished indeed to make it a boy's class- 
book, which should reveal the mode of life, as well as the 
scientific objects, of an explorer of the Alps. The incidents 
of the past year have, caused me to deviate, in some degree, 
from this intention, but its traces will be sufficiently mani- 
fest; and this reference to it will, I trust, excuse an 
occasional liberty of style and simplicity of treatment 
which would be out of place if intended for a reader of 
riper years. 



1856.] THE OBERLAND. 9 

EXPEDITION OF 1856. 

THE OBERLAND. 
(2.) 

ON the 16th of August, 1856, I received my Alpenstock 
from the hands of Dr. Hooker, in the garden of the Pension 
Ober, at Interlaken. It bore my name, not marked, how- 
ever, by the vulgar brands of the country, but by the solar 
beams which had been converged upon it by the pocket 
lens of my friend. I was the companion of Mr. Huxley, 
and our first aim was to cross the Wengern Alp. Light 
and shadow enriched the crags and green slopes as we 

Ivanced up the valley of Lauterbrunnen, and each 
occupied himself with that which most interested him. 
My companion examined the drift, I the cleavage, while 
both of us looked with interest at the contortions of the 
strata to our left, and at the shadowy, unsubstantial aspect 
of the pines, gleaming through the sunhaze to our right. 

What was the physical condition of the rock when it was 
thus bent and folded like a pliant mass ? Was it neces- 
sarily softer than it is at present ? I do not think so. The 
shock which would crush a railway carriage, if communi- 
cated to it at once, is harmless when distributed over the 
interval necessary for the pushing in of the buffer. By 
suddenly stopping a cock from which water flows you may 
burst the conveyance pipe, while a slow turning of the cock 
keeps all safe. Might not a solid rock by ages of pressure 
be folded as above ? It is a physical axiom that no body is 
perfectly hard, none perfectly soft, none perfectly elastic. 
The hardest body subjected to pressure yields, however 
little, and the same body when the pressure is removed 



10 FOLDED EOCKS. [1856. 

cannot return to its original form. If it did not yield in 
the slightest degree it would be perfectly hard ; if it could 
completely return to its original shape it would be perfectly 
elastic. 

Let a pound weight be placed upon a cube of granite ; 
the cube is flattened, though in an infinitesimal degree. 
Let the weight be removed, the cube remains a little 
flattened; it cannot quite return to its primitive condition. 
Let us call the cube thus flattened No. 1. Starting with 
No. 1 as a new mass, let the pound weight be laid upon it ; 
the mass yields, and on removing the weight it cannot 
return to the dimensions of No. 1 ; we have a more flat- 
tened mass, No. 2. Proceeding in this manner, it is manifest 
that by a repetition of the process we should produce a 
series of masses, each succeeding one more flattened than 
the former. This appears to be a necessary consequence 
of the physical axiom referred to above. 

Now if, instead of removing and replacing the weight in 
the manner supposed, we cause it to rest continuously upon 
the cube, the flattening, which above was intermittent, will 
be continuous ; no matter how hard the cube may be, 
there will be a gradual yielding of its mass under the 
pressure. Apply this to squeezed rocks to those, for 
example, which form the base of an obelisk like the 
Matterhorn; that this base must yield, seems a certain 
consequence of the physical constitution of matter : the 
conclusion seems inevitable that the mountain is sinking 
by its own weight. Let two points be fixed, one near 
the summit, the other near the base of the obelisk ; next 
year these points will have approached each other. Whether 
the amount of approach in a human lifetime be measure- 
able we know not ; but it seems certain that ages would 
leave their impress upon the mass, and render visible to 
the eye an action which at present is appreciable by the 
imagination only. 



1856.] THE JUNGFRAU AND SILBERHOKN. 11 






We halted on the night of the 16th at the Jungfrau 
Hotel, and next morning we saw the beams of the rising 
sun fall upon the peaked snow of the Silberhorn. Slowly 
and solemnly the pure white cone appeared to rise higher 
and higher into the sunlight, being afterwards mottled with 
gold and gloom, as clouds drifted between it and the sun. 
I descended alone towards the base of the mountain, 
making my way through a rugged gorge, the sides of 
which were strewn with pine-trees, splintered, broken 
across, and torn up by the roots. I finally reached the 
end of a glacier, formed by the snow and shattered ice 
which fall from the shoulders of the Jungfrau. The view 
from this place had a savage magnificence such as I had 
not previously beheld, and it was not without some slight 
feeling of awe that I clambered up the end of the glacier. 
It was the first I had actually stood upon. The lone- 
liness of the place was very impressive, the silence being 
only broken by fitful gusts of wind, or by the weird rattle 
of the debris which fell at intervals from the melting ice. 

Once I noticed what appeared to be the sudden and 
enormous augmentation of the waters of a cascade, but the 
sound soon informed me that the increase was due to an 
avalanche which had chosen the track of the cascade for 
its rush. Soon afterwards my eyes were fixed upon a white 
slope some thousands of feet above me; I saw the ice 
give way, and, after a sensible interval, the thunder of 
another avalanche reached me. A kind of zigzag chan- 
nel had been worn on the side of the mountain, and 
through this the avalanche rushed, hidden at intervals, and 
anon shooting forth, and leaping like a cataract down the 
precipices. The sound was sometimes continuous, but 
f sometimes broken into rounded explosions which seemed 
to assert a passionate predominance over the general level 
of the roar. These avalanches, when they first give way, 
usually consist of enormous blocks of ice, which are more 



12 AVALANCHES. [1856. 

and more shattered as they descend. Partly to the echoes 
of the first crash, but mainly, I think, to the shock of the 
harder masses which preserve their cohesion, the explosions 
which occur during the descent of the avalanche are to 
be ascribed. Much of the ice is crushed to powder ; and 
thus, when an avalanche pours cataract-like over a ledge, 
the heavier masses, being less influenced by the atmo- 
spheric resistance, shoot forward like descending rockets, 
leaving the lighter powder in trains behind them. Such is 
the material of which a class of the smaller glaciers in the 
Alps is composed. They are the products of avalanches, 
the crushed ice being recompacted into a solid mass, which 
exhibits on a smaller scale most of the characteristics of 
the large glaciers. 

After three hours' absence I reascended to the hotel, 
breakfasted, and afterwards returned with Mr. Huxley to 
the glacier. While we were engaged upon it the weather 
suddenly changed ; lightning flashed about the summits ot 
the Jungfrau, and thunder u leaped " among her crags. 
Heavy rain fell, but it cleared up afterwards with magical 
speed, and we returned to our hotel. Heedless of the 
forebodings of many prophets of evil weather we set out for 
Grindelwald. The scene from the summit of the Little 
Scheideck was exceedingly grand. The upper air ex- 
hibited a commotion which we did not experience ; clouds 
were wildly driven against the flanks of the Eiger, the 
Jungfrau thundered behind, while in front of us a magni- 
ficent rainbow, fixing one of its arms in the valley ol 
Grindelwald, and, throwing the other right over the crown 
of the Wetterhorn, clasped the mountain in its embrace. 
Through jagged apertures in the clouds floods of golden 
light were poured down the sides of the mountain. On 
the slopes were innumerable chalets, glistening in the 
sunbeams, herds browsing peacefully and shaking their 
mellow bells ; while the blackness of the pine-trees, crowded 



556.] THE HEISSE PLATTE. 13 

ito woods, or scattered in pleasant clusters over alp and 
lley, contrasted forcibly with the lively green of the 
ields. 

At Grindelwald, on the 18th, we engaged a strong and 
competent guide, named Christian Kaufmann, and pro- 
ceeded to the Lower Glacier. After a steep ascent, we 
gained a point from which we could look down upon the 
frozen mass. At first the ice presented an appearance of 
utter confusion, but we soon reached a position where the 
mechanical conditions of the glacier revealed themselves, 
and where we might learn, had we not known it before, 
that confusion is merely the unknown intermixture of laws, 
and becomes order and beauty when we rise to their com- 
prehension. We reached the so-called Eismeer Ice Sea. 
In front of us was the range of the Viescherhorner, and a 
vast snow slope, from which one branch of the glacier 
was fed. Near the base of this neve, and surrounded on 
all sides by ice, lay a brown rock, to which our attention 
was directed as a place noted for avalanches ; on this 
rock snow or ice never rests, and it is hence called the 
ffeisse Platte the Hot Plate. At the base of the rock, 
and far below it, the glacier was covered with clean crushed 
ice, which had fallen from a crown of frozen cliffs en- 
circling the brow of the rock. One obelisk in particular 
signalised itself from all others by its exceeding grace and 
beauty. Its general surface was dazzling white, but from 
its clefts and fissures issued a delicate blue light, which 
deepened in hue from the edges inwards. It stood upon a 
pedestal of its own substance, and seemed as accurately 
fixed as if rule and plummet had been employed in its 
erection. Fig. 1 represents this beautiful minaret of ice. 

While we were in sight of the Heisse Platte, a dozen 
avalanches rushed downwards from its summit. In most 
cases we were informed of the descent of an avalanche by 
the sound, but sometimes the white mass was seen gliding 



14 



ICE MINABET. 



[1856. 



down the rock, and scattering its smoke in the air, long 
before the sound reached us. It is difficult to reconcile the 
insignificant appearance presented by avalanches, when seen 
from a distance, with the volume of sound which they 







Fig. 1. 

generate ; but 011 this day we saw sufficient to account for 
the noise. One block of solid ice which we found below 
the Heisse Platte measured 7 feet 6 inches in length, 5 feet 
8 inches in height, and 4 feet 6 inches in depth. A second 
mass was 10 feet long, 8 feet high, and 6 feet wide. It 
contained therefore 480 cubic feet of ice, which had been 
cast to a distance of nearly 1000 yards down the glacier. 
The shock of such hard and ponderous projectiles against 
rocks and ice, reinforced by the echoes from the surrounding 



1856.] ECHOES OF THE WETTERHOEN. 15 

- 

mountains, will appear sufficient to account for the peals 
by which their descent is accompanied. 

A second day, in company with Dr. Hooker, completed 
ihe examination of this glacier in 1856 ; after which I 
parted from my friends, Mr. Huxley intending to rejoin me 
at the Grimsel. On the morning of the 20th of August I 
strapped on my knapsack and ascended the green slopes 
from Grindelwald towards the Great Scheideck. Before 
reaching the summit I frequently heard the wonderful 
echoes of the Wetterhorn. Some travellers were in advance 
of me, and to amuse them an alpine horn was blown. The 
direct sound was cut off from me by a hill, but the echoes 
talked down to me from the mountain walls. The sonorous 
waves arrived after one, two, three, and more reflections, 
diminishing gradually in intensity, but increasing in soft- 
ness, as if in its wanderings from crag to crag the sound 
had undergone a kind of sifting process, leaving all its 
grossness behind, and returning in delightful flute notes to 
the ear. 

Let us investigate this point a little. If two looking- 
glasses be placed perfectly parallel to each other, with a 
lighted candle between them, an infinite series of images of 
the candle will be seen at both sides, the images diminishing 
in brightness the further they recede. But if the looking- 
glasses, instead of being parallel, enclose an angle, a limited 
number of images only will be seen. The smaller the 
angle which the reflectors make with each other, or, in 
other words, the nearer they approach parallelism, the 
greater will be the number of images observed. 

To find the number of images the following is the rule : 
Divide 360, or the number of degrees in a circle, by the 
number of degrees in the angle enclosed by the two mirrors, 
the quotient will be one more than the number of images ; 
or, counting the object itself, the quotient is always equal 
to the number of images plus the object. In Fig. 2 1 have 



16 



ECHOES EXPLAINED. 



[1856. 




Fig. 2. 



given the number and position of the images produced by 
two mirrors placed at an angle of 45. A B and B c mark 

the edges of the mirrors, 
and o represents the can- 
dle, which, for the sake 
of simplicity, I have 
placed midway between 
them. Fix one point of 
a pair of compasses at 
B, and with the distance 
B o sweep a circle : all 
the images will be ranged 
upon the circumference of 
this circle. The number 
of images found by the 
foregoing rule is 7, and 
their positions are marked in the figure by the numbers 1, 
2, 3, &c. 

Suppose the ear to occupy the place of the eye, and 
that a sounding body occupies the place of the luminous 
one, we should then have just as many echoes as we had 
images in the former case. These echoes would diminish 
in loudness just as the images of the candle diminish in 
brightness. At each reflection a portion both of sound and 
light is lost ; hence the oftener light is reflected the dimmer 
it becomes, and the oftener sound is reflected the fainter 
it is. 

Now the cliffs of the Wetterhorn are so many rough 
angular reflectors of the sound : some of them send it back 
directly to the listener, and we have a first echo ; some of 
them send it on to others from which it is again re- 
flected, forming a second echo. Thus, by repeated reflec- 
tion, successive echoes are sent to the ear, until, at length, 
they become so faint as to be inaudible. The sound, as 
it diminishes in intensity, appears to come from greater 



1856.] KEICHENBACH AND HANDECK. 17 

and greater distances, as if it were receding into the moun- 
tain solitudes ; the final echoes being inexpressibly soft and 
pure. 

After crossing the Scheideck I descended to Meyringen, 
visiting the Reichenbach waterfall on my way. A pecu- 
liarity of the descending water here is, that it is broken up 
in one of the basins into nodular masses, each of which in 
falling leaves the light foaming mass which surrounds it as 
a train in the air behind ; the effect exactly resembles 
that of the avalanches of the Jungfrau, in which the more 
solid blocks of ice shoot forward in advance of the lighter 
debris, which is held back by the friction of the air. 

Next day I ascended the valley of Hasli, and observed 
upon the rocks and mountains the action of ancient glaciers 
which once filled the valley to the height of more than a 
thousand feet above its present level. I paused, of course, 
at the waterfall of Handeck, and stood for a time upon 
the wooden bridge which spans the river at its top. The 
Aar comes gambolling down to the bridge from its parent 
glacier, takes one short jump upon a projecting ledge, 
boils up into foam, and then leaps into a chasm, from the 
bottom of which its roar ascends through the gloom. A 
rivulet named the Aarlenbach joins the Aar from the left 
in the very jaws of the chasm : falling, at first, upon a 
projection at some depth below the edge, and, rebound- 
ing from this, it darts at the Aar, and both plunge 
together like a pair of fighting demons to the bottom of 
the gorge. The foam of the Aarlenbach is white, that 
of the Aar is yellow, and this enables the observer to trace 
the passage of the one cataract through the other. As I 
stood upon the bridge the sun shone brightly upon the 
spray and foam ; my shadow was oblique to the river, and 
'hence a symmetrical rainbow could not be formed in the 
spray, but one half of a lovely bow, with its base in the 
chasm, leaned over against the opposite rocks, the colours 

c 



18 HUT OF M. DOLLFUSS. [1856. 

advancing and retreating as the spray shifted its position. 
I had been watching the water intently for some time, 
when a little Swiss boy, who stood beside me, observed, 
in his trenchant German, u There plunge stones ever 
downwards." The stones were palpable enough, carried 
down by the cataract, and sometimes completely breaking 
loose from it, but I did not see them until my attention 
was withdrawn from the water. 

On my arrival at the Grimsel I found Mr. Huxley already 
there, and, after a few minutes' conversation, we decided to 
spend a night in a hut built by M. Dollfuss in 1846, beside 
the Unteraar glacier, about 2000 feet above the Hospice. 
We hoped thus to be able to examine the glacier to its 
origin on the following day. Two days' food and some 
blankets were sent up from the Hospice, and, accompanied 
by our guide, we proceeded to the glacier. 

Having climbed a great terminal moraine, and tramped 
for a considerable time amid loose shingle and boulders, 
we came upon the ice. The finest specimens of " tables " 
which I have ever seen are to be found upon this glacier 
huge masses of clean granite poised on pedestals of ice. 
Here are also " dirt-cones " of the largest size, and nume- 
rous shafts, the forsaken passages of ancient " moulins," 
some filled with water, others simply with deep blue light. 
I reserve the description and explanation of both cones 
and moulins for another place. The surfaces of some of 
the small pools were sprinkled lightly over with snow, 
which the water underneath was unable to melt ; a coating 
of snow granules was thus formed, flexible as chain armour, 
but so close that the air could not escape through it. 
Some bubbles which had risen through the water had lifted 
the coating here and there into little rounded domes, 
which, by gentle pressure, could be shifted hitherand thither, 
and several of them collected into one. We reached the 
hut, the floor of which appeared to be of the original moun- 



1856.] H6TEL DES NEUFCHATELOIS. 19 

tain slab ; there was a space for cooking walled off from 
the sleeping-room, half of which was raised above the floor, 
and contained a quantity of old hay. The number 2404 
metres, the height, I suppose, of the place above the sea, 
was painted on the door, behind which were also the names 
of several well-known observers Agassiz, Forbes, Desor, 
Dollfuss, Ramsay, and others cut in the wood. A loft con- 
tained a number of instruments for boring, a surveyor's 
chain, ropes, and other matters. After dinner I made my 
way alone towards -the junction of the Finsteraar and 
Lauteraar glaciers, which unite at the Abschwung to form 
the trunk stream of the Unteraar glacier. Upon the great 
central moraine which runs between the branches were 
perched enormous masses of rock, and, under the over- 
hanging ledge of one of these, M. Agassiz had his Hotel 
des Neufchdtelois. The rock is still there, bearing traces of 
names now nearly obliterated by the weather, while the 
fragments around also bear inscriptions. There in the 
wilderness, in the gray light of evening, these blurred and 
faded evidences of human activity wore an aspect of sad- 
ness. It was a temple of science now in ruins, and I a 
solitary pilgrim to the desecrated blocks. As the day de- 
clined, rain began to fall, and I turned my face towards 
my new home ; where in due time we betook ourselves to 
our hay, and waited hopefully for the morning. 

But our hopes were doomed to disappointment. A vast 
[uantity of snow fell during the night, and, when we arose, 
found the glacier covered, and the air thick with the 
descending flakes. We waited, hoping that it might clear 
up, but noon arrived and passed without improvement; 
our fire-wood was exhausted, the weather intensely cold, 
and, according to the men's opinion, hopelessly bad ; 
they opposed the idea of ascending further, and we had 
therefore no alternative but to pack up and move down- 
wards. What was snow at the higher elevations changed 

c 2 



20 THE RHONE GLACIEE. [1856 

to rain lower down, and drenched us completely before we 
reached the Grimsel. But though thus partially foiled in 
our design, this visit taught us much regarding the struc- 
ture and general phenomena of the glacier. 

The morning of the 24th was clear and calm : we rose 
with the sun, refreshed and strong, and crossed the Grimsel 
pass* at an early hour. The view from the summit of the 
pass was lovely in the extreme ; the sky a deep blue, the 
surrounding summits all enamelled with the newly-fallen 
snow, which gleamed with dazzling whiteness in the sun- 
light. It was Sunday, and the scene was itself a Sabbath, 
with no sound to disturb its perfect rest. In a lake which 
we passed the mountains were mirrored without distortion, 
for there was no motion of the air to ruffle its surface. From 
the summit of the Mayenwand we looked down upon the 
Ehone glacier, and a noble object it seemed, I hardly 
know a finer of its kind in the Alps. Forcing itself 
through the narrow gorge which holds the ice cascade in 
its jaws, and where it is greatly riven and dislocated, it 
spreads out in the valley below in such a manner as 
clearly to reveal to the mind's eye the nature of the 
forces to which it is subjected. Longfellow's figure is quite 
correct ; the glacier resembles a vast gauntlet, of which the 
gorge represents the wrist ; while the lower glacier, cleft 
by its fissures into finger-like ridges, is typified by the hand. 

Furnishing ourselves with provisions at the adjacent inn, 
we devoted some hours to the examination of the lower 
portion of the glacier. The dirt upon its surface was 
arranged in grooves as fine as if produced by the passage 
of a rake, while the laminated structure of the deeper ice 
always corresponded to the superficial grooving. We 
found several shafts, some empty, some filled with water. 
At one place our attention was attracted by a singular noise, 
evidently produced by the forcing of air and water through 
passages in the body of the glacier ; the sound rose and 




KINGS AROUND THE SUN. 21 

fell for several minutes, like a kind of intermittent snore, re- 
minding one of Hugi's hypothesis that the glacier was alive. 
We afterwards climbed to a point from which the whole 
glacier was visible to us from its origin to its end. Adjacent 
to us rose the mighty mass of the Finsteraarhorn, the 
monarch of the Oberland. The Galenstock was also at 
hand, while round about the neve of the glacier a mountain 
wall projected its jagged outline against the sky. At a 
distance was the grand cone of the Weisshorn, then, and I 
believe still, unsealed ; * further to the left the magnificent 
peaks of the Mischabel ; while between them, in savage 
isolation, stood the obelisk of the Matterhorn. Near us was 
the chain of the Furca, all covered with shining snow, while 
overhead the dark blue of the firmament so influenced 
the general scene as to inspire a sentiment of wonder 
approaching to awe. We descended to the glacier, and 
proceeded towards its source. As we advanced an unusual 
light fell upon the mountains, and looking upwards we 
saw a series of coloured rings, drawn like a vivid cir- 
cular rainbow quite round the sun. Between the orb 
and us spread a thin veil of cloud on which the circles 
were painted; the western side of the veil soon melted 
away, and with it the colours, but the eastern half remained 
a quarter of an hour longer, and then in its turn disap- 
peared. The crevasses became more frequent and dan- 
gerous as we ascended. They were usually furnished with 
overhanging eaves of snow, from which long icicles de- 
pended, and to tread on which might be fatal. We were 
near the source of the glacier, but the time necessary to 
reach it was nevertheless indefinite, so great was the entan- 
glement of fissures. We followed one huge chasm for some 
hundreds of yards, hoping to cross it ; but after half an 
hour's fruitless effort we found ourselves baffled and forced 
to retrace our steps. 

* [The Weisshorn was first scaled, by Tyndall, in 1861. L. C. T.J 



22 SPIRIT OF THE BKOCKEN. [1856. 

The sun was sloping to the west, and we thought it wise 
to return ; so down the glacier we went, mingling our 
footsteps with the tracks of chamois, while the frightened 
marmots piped incessantly from the rocks. We reached 
the land once more, and halted for a time to look upon 
the scene within view. The marvellous blueness of the 
sky in the earlier part of the day indicated that the air was 
charged, almost to saturation, with transparent aqueous 
vapour. As the sun sank the shadow of the Finsteraar- 
horn was cast through the adjacent atmosphere, which, 
thus deprived of the direct rays, curdled up into visible 
fog. The condensed vapour moved slowly along the flanks 
of the mountain, and poured itself cataract-like into the 
valley of the Ehone. Here it met the sun again, which 
reduced it once more to the invisible state. Thus, though 
there was an incessant supply from the generator behind, 
the fog made no progress ; as in the case of the moving 
glacier, the end of the cloud-river remained stationary 
where consumption was equal to supply. Proceeding along 
the mountain to the Furca, we found the valley at the 
further side of the pass also filled with fog, which rose, like 
a wall, high above the region of actual shadow. Once on 
turning a corner an exclamation of surprise burst simul- 
taneously from my companion and myself. Before each 
of us and against the wall of fog, stood a spectral image 
of a man, of colossal dimensions ; dark as a whole, but 
bounded by a coloured outline. We stretched forth our 
arms ; the spectres did the same. We raised our alpen- 
stocks ; the spectres also flourished their batons. All our 
actions were imitated by these fringed and gigantic shades. 
We had, in fact, the Spirit of the Brocken before us in per- 
fection. 

At the time here referred to I had had but little expe- 
rience of alpine phenomena. I had been through the 
Oberland in 1850, but was then too ignorant to learn 



1856.] THE TYROL. 23 

much from my excursion. Hence the novelty of this day's 
experience may have rendered it impressive : still even 
now I think there was an intrinsic grandeur in its phenomena 
which entitles the day to rank with the most remarkable 
that I have spent among the Alps. At the Furca, to my 
great regret, the joint ramblings of my friend and myself 
ended ; I parted from him on the mountain side, and 
watched him descending, till the gray of evening finally 
hid him from my view, 



THE TYROL. 

(3.) ' 

MY subsequent destination was Vienna ; but I wished to 
associate with my journey thither a visit to some of the 
glaciers of the Tyrol. At Landeck, on the 29th of August, 
I learned that the nearest glacier was that adjacent to the 
Gebatsch Alp, at the head of the Kaunserthal ; and on 
the following morning I was on my way towards this valley. 
I sought to obtain a guide at Kaltebrunnen, but failed ; 
and afterwards walked to the little hamlet of Feuchten, 
where I put up at a very lonely inn. My host, I believe, 
had never seen an Englishman, but he had heard of such, 
and remarked to me in his patois with emphasis, " Die 
Englcinder sind die Mhnsten Leute in dieser Welt." Through 
his mediation I secured a chamois -hunter, named Johann 
Auer, to be my guide, and next morning I started with this 
man up the valley. The sun, as we ascended, smote the 
earth and us with great power ; high mountains flanked 
us on either side, while in front of us, closing the view, was 
the mass of the Weisskugel, covered with snow. At three 



24 THE GEBATSCH ALP. [1856. 

o'clock we came in sight of the glacier, and soon afterwards 
I made the acquaintance of the Senner or cheesemakers of 
the Gebatsch Alp. 

The chief of these was a fine tall fellow, with free, frank 
countenance, which, however, had a dash of the mountain 
wildness in it. His feet were bare, he wore breeches, and 
fragments of stockings partially covered his legs, leaving 
a black zone between the upper rim of the sock and the 
breeches. His feet and face were of the same swarthy 
hue ; still he was handsome, and in a measure pleasant 
to look upon. He asked me what he could cook for me, 
and I requested some bread and milk ; the former was a 
month old, the latter was fresh and delicious, and 011 these 
I fared sumptuously. I went to the glacier afterwards 
with my guide, and remained upon the ice until twilight, 
when we returned, guided by no path, but passing amid 
crags grasped by the gnarled roots of the pine, through 
green dells, and over bilberry knolls of exquisite colouring. 
My guide kept in advance of me singing a Tyrolese 
melody, and his song and the surrounding scene revived 
and realised all the impressions of my boyhood regarding 
the Tyrol. 

Milking was over when we returned to the chalet, which 
now contained four men exclusive of myself and my guide. 
A fire of pine logs was made upon a platform of stone, 
elevated three feet above the floor ; there was no chimney, 
as the smoke found ample vent through the holes and 
fissures in the sides and roof. The men were all intensely 
sunburnt, the legitimate brown deepening into black with 
beard and dirt. The chief senner prepared supper, break- 
ing eggs into a dish, and using his black fingers to empty 
the shell when the albumen was refractory. A fine 
erect figure he was as he stood in the glowing light of the 
fire. All the men were smoking, and now and then a 
brand was taken from the fire to light a renewed pipe, and 



1856.] AN ALPINE CHALET. 25 

a ruddy glare flung thereby over the wild countenance of 
the smoker. In one corner of the chalet, and raised high 
above the ground, was a large bed, covered with clothes 
of the most dubious black-brown hue ; at one end was a 
little water-wheel turned by a brook, which communi- 
cated motion to a churndash which made the butter. The 
beams and rafters were covered with cheeses, drying in the 
warm smoke. The senner, at my request, showed me his 
storeroom, and explained to me the process of making 
cheese, its interest to me consisting in its bearing upon 
the question of slaty cleavage. Three 'gigantic masses of 
butter were in the room, and I amused my host by calling 
them butter-glaciers. Soon afterwards a bit of cotton was 
stuck in a lump of grease, which was placed in a lantern, 
and the wick ignited ; the chamois-hunter took it, and led 
the way to our resting-place, I having previously declined 
a good-natured invitation to sleep in the big black bed 
already referred to. 

There was a cowhouse near the chalet, and above it, 
raised on pillars of pine, and approached by a ladder, was 
a loft, which contained a quantity of dry hay : this my 
guide shook to soften the lumps, and erected an eminence 
for my head. I lay down, drawing my plaid over me, but 
Auer affirmed that this would not be a sufficient protec- 
tion against the cold ; he therefore piled hay upon me to 
the shoulders, and proposed covering up my head also. 
This, however, I declined, though the biting coldness of 
the air, which sometimes blew in upon us, afterwards 
proved to me the wisdom of the suggestion. Having set 
me right, my chamois-hunter prepared a place for himself, 
and soon his heavy breathing informed me that he was 
in a state of bliss which I could only envy. One by one 
the stars crossed the apertures in the roof. Once the 
Pleiades hung above me like a cluster of gems ; I tried to 
admire them, but there was no fervour in my admiration. 



26 THE GEBATSCH GLACIEK. [1856. 

Sometimes I dozed, but always as this was about to deepen 
into positive sleep it was rudely broken by the cla- 
mour of a group of pigs which occupied the ground-floor 
of our dwelling. The object of each individual of the 
group was to secure for himself the maximum amount of 
heat, and hence the outside members were incessantly 
trying to become inside ones. It was the struggle of 
radical and conservative among the pachyderms, the politics 
being determined by the accident of position. 

I rose at five o'clock on the 1st of September, and after 
a breakfast of black bread and milk ascended the glacier 
as far as practicable. We once quitted it, crossed a pro- 
montory, and descended upon one of its branches, which 
was flanked by some fine old moraines. We here came 
upon a group of seven marmots, which with yells of 
terror scattered themselves among the rocks. The points 
of the glacier beyond my reach I examined through a 
telescope ; along the faces of the sections the lines of stra- 
tification were clearly shown ; and in many places where 
the mass showed manifest signs of lateral pressure, I 
thought I could observe the cleavage passing though the 
strata. The point, however, was too important to rest 
upon an observation made from such a distance, and I 
therefore abstained from mentioning it subsequently. I 
examined the fissures and the veining, and noticed how 
the latter became most perfect in places where the pres- 
sure was greatest. The effect of ollique pressure was also 
finely shown : at one place the thrust of the descending 
glacier was opposed by the resistance offered by the side 
of the valley, the direction of the force being oblique to 
the side ; the consequence was a structure nearly parallel 
to the valley, and consequently oblique to the thrust which 
I believe to be its cause. 

After five hours' examination we returned to our chalet, 
where we refreshed ourselves, put our things in order, and 



1856.] A CHAMOIS ON THE ROCKS. 27 

faced a nameless " Joch," or pass ; our aim being to cross 
the mountains into the valley of Lantaufer, and reach 
Graun that evening. After a rough ascent over the alp 
we came to the dead crag, where the weather had broken 
up the mountains into ruinous heaps of rock and shingle. 
We reached the end of a glacier, the ice of which was 
covered by sloppy snow, and at some distance up it came 
upon an islet of stones and debris, where we paused to rest 
ourselves. My guide, as usual, ranged over the summits 
with his telescope, and at length exclaimed, " I see a 
chamois." The creature stood upon a cliff some hundreds 
of yards to our left, and seemed to watch our movements. 
It was a most graceful animal, and its life and beauty stood 
out in forcible antithesis to the surrounding savagery and 
death. 

On the steep slopes of the glacier I was assisted by the 
hand of my guide. In fact, on this day I deemed places 
dangerous, and dreaded them as such, which subsequent 
practice enabled ine to regard with perfect indifference ; 
so much does what we call courage depend upon habit, or 
on the fact of knowing that we have really nothing to fear. 
Doubtless there are times when a climber has to make up 
his mind for very unpleasant possibilities, and even gather 
calmness from the contemplation of the worst ; but in most 
cases I should say that his courage is derived from the 
latent feeling that the chances of safety are immensely in 
his favour. 

After a tough struggle we reached the narrow row of 
crags which form the crest- of the pass, and looked into 
the world of mountain and cloud on the other side. The 
scene was one of stern grandeur the misty lights and 
deep cloud-glooms being so disposed as to augment the 
impression of vast-ness which the scene conveyed. The 
breeze at the summit was exceedingly keen, but it gave 
our muscles tone, and we sprang swiftly downward 



28 PASSAGE OF A JOCH. [1856. 

through the yielding debris which here overlies the moun- 
tain, and in which we sometimes sank to the knees. 
Lower down we came once more upon the ice. The 
glacier had at one place melted away from its bounding 
cliff, which rose vertically to our right, while a wall of ice 
60 or 80 feet high was on our left. Between the two was 
a narrow passage, the floor of which was snow, which 
I knew to be hollow beneath : my companion, however, 
was in advance of me, and he being the heavier man, 
where he trod I followed without hesitation. On turn- 
ing an angle of the rock I noticed an expression of 
concern upon his countenance, and he muttered audibly, 
" I did not expect this." The snow-floor had, in fact, 
given way, and exposed to view a clear green lake, one 
boundary of which was a sheer precipice of rock, and the 
other the aforesaid wall of ice ; the latter, however, curved 
a little at its base, so as to form a short steep slope 
which overhung the water. My guide first tried the slope 
alone ; biting the ice with his shoe-nails, and holding on 
by the spike of his baton, he reached the other side. He 
then returned, and, divesting myself of all superfluous 
clothes, as a preparation for the plunge which I fully 
expected, I also passed in safety. Probably the conscious- 
ness that I had water to fall into instead of pure space, 
enabled me to get across without anxiety or mischance ; 
but had I, like my guide, been unable to swim, my feelings 
would have been far different. 

This accomplished, we went swiftly down the valley, 
and the more I saw of my g.uide the more I liked him. 
He might, if he wished, have made his day's journey 
shorter by stopping before he reached Graun, but he 
would not do so. Every word he said to me regarding 
distances was true, and there was not the slightest desire 
shown to magnify his own labour. I learnt by mere acci- 
dent that the day's work had cut up his feet, but his 



1856.] THE STELVIO. 29 

cheerfulness and energy did not bate a jot till he had landed 
me in the Black Eagle at Graun. Next morning he came 
to my room, and said that he felt sufficiently refreshed 
to return home. I paid him what I owed him, when 
he took my hand, and, silently bending down his head, 
kissed it ; then, standing erect, he stretched forth his 
right hand, which I grasped firmly in mine, and bade him 
farewell ; and thus I parted from Johann Auer, my brave 
and truthful chamois-hunter. 

On the following day I met Dr. Frankland in the Finster- 
muntz pass, and that night we bivouacked together at 
Mais. Heavy rain fell throughout the night, but it came 
from a region high above that of liquidity. It was first 
snow, which, as it descended through the warmer strata 
of the atmosphere, was reduced to water. Overhead, in 
the air, might be traced a surface, below which the preci- 
pitate was liquid, above which it was solid ; and this sur- 
face, intersecting the mountains which surround Mais, 
marked upon them a beautifully-defined snow-line, below 
which the pines were dark and the pastures green, but 
above which pines and pastures and crags were covered 
with the freshly-fallen snow. 

On the 2nd of September we crossed the Stelvio. The 
brown cone of the well-known Madatschspitze was clear, but 
the higher summits were clouded, and the fragments of sun- 
shine which reached the lower world wandered like gleams 
of fluorescent light over the glaciers. Near the snow- line 
the partial melting of the snow had rendered it coarsely 
granular, but as we ascended it became finer, and the light 
emitted from its cracks and cavities a pure and deep 
blue. When a staff was driven into the snow low down 
the mountain, the colour of the light in the orifice was 
scarcely sensibly blue, but higher up this increased in a 
wonderful degree, and at the summit the effect was mar- 
vellous. I struck my staff into the snow, and turned it 



30 COLOUR OF FRESH SNOW. [1856. 

round and round ; the surrounding snow cracked repeat- 
edly, and flashes of blue light issued from the fissures. 
The fragments of snow that adhered to the staff were, by 
contrast, of a beautiful pink yellow, so that, on moving the 
staff with such fragments attached to it up and down, it 
was difficult to resist the impression that a pink flame was 
ascending and descending in the hole. As we went down 
the other side of the pass, the effect became more and 
more feeble, until, near the snow-line, it almost wholly dis- 
appeared. 

We remained that night at the baths of Bormio, but the 
following afternoon being fine we wished to avail ourselves 
of the fair weather to witness the scene from the summit of 
the pass. Twilight came on before we reached Santa Maria, 
but a gorgeous orange overspread the western horizon, from 
which we hoped to derive sufficient light. It was a little 
too late when we reached the top, but still the scene was 
magnificent. A multitude of mountains raised their crowns 
towards heaven, while above all rose the snow-white cone 
of the Ortler. Far into the valley the giant stretched his 
granite limbs, until they were hid from us by darkness. As 
this deepened, the heavens became more and more crowded 
with stars, which blazed like gems over the heads of the 
mountains. At times the silence was perfect, unbroken 
save by the crackling of the frozen snow beneath our own 
feet ; while at other times a breeze would swoop down 
upon us, keen and hostile, scattering the snow from the roofs 
of the wooden galleries in frozen powder over us. Long 
after night had set in, a ghastly gleam rested upon the 
summit of the Ortler, while the peaks in front deepened to 
a dusky neutral tint, the more distant ones being lost in 
gloom. We descended at a swift pace to Trafoi, which we 
reached before 1 1 P.M. 

Meran was our next resting-place, whence we turned 
through the Schnalzerthal to Unserfrau, and thence over 



1856.] SINGULAE HAILSTOEM. 31 

the Hochjoch to Fend. From a religious procession we 
took a guide, who, though partly intoxicated, did his duty 
well. Before reaching the summit of the pass we were 
assailed by a violent hailstorm, each hailstone being a 
frozen cone with a rounded end. Had not their motion 
through the air something to do with the shape of these 
hailstones? The theory of meteorites now generally 
accepted is that they are small planetary bodies drawn to 
the earth by gravity, and brought to incandescence by 
friction against the earth's atmosphere. Such a body 
moving through the atmosphere must have condensed hot 
air in front of it, and rarefied cool air behind it ; and the 
same is true to a small extent of a hailstone. This distri- 
bution of temperature must, I imagine, have some influence 
on the shape of the stone. Possibly also the stratified ap- 
pearance of some hailstones may be connected with this 
action.* 

The hail ceased and the heights above us cleared as we 
ascended. At the top of the pass we found ourselves on 
the verge of a great neve, which lay between two ranges of 
summits, sloping down to the base of each range from a 
high and rounded centre : a wilder glacier scene I have 
scarcely witnessed. Wishing to obtain a more perfect 
view of the region, I diverged from the track followed by 
Dr. Frankland and the guide, and climbed a ridge of snow 
about half a mile to the right of them. A glorious expanse 

* I take the following account of a grander storm of the above charac- 
ter from Hooker's ' Himalayan Journals,' vol. ii. p. 405. 

" On the 20th (March, 1849) we had a change in the weather : a violent 
storm from the south-west occurred at noon, with hail of a strange form, 
the stones being sections of hollow spheres, half an inch across and up- 
wards, formed of cones with truncated apices and convex bases : these 
cones were aggregated together with their bases outwards. The large 
masses were followed by a shower of the separate conical pieces, and that 
by heavy rain. On the mountains this storm was most severe : the stones 
lay at Darjeeling for seven days, congealed into masses of ice several feet 
long and a foot thick in sheltered places : at Purneah, fifty miles south, 
stones one and two inches across fell, probably as whole spheres." 



32 THE HOCHJOCH AND FEND. [1856. 

was before me, stretching itself in vast undulations, and 
heaping itself here and there into mountainous cones, 
white and pure, with the deep blue heaven behind them. 
Here I had my first experience of hidden crevasses, and to 
niy extreme astonishment once found myself in the jaws of 
a fissure of whose existence I had not the slightest notice. 
Such accidents have often occurred to me since, but the 
impression made by the first is likely to remain the 
strongest. It was dark when we reached the wretched ' 
Wirthshaus at Fend, where, badly fed, badly lodged, and 
disturbed by the noise of innumerable rats, we spent 
the night. Thus ended my brief glacier expedition of 
1856 ; and on the observations then made, and on subsequent 
experiments, was founded a paper presented to the Royal 
Society by Mr. Huxley and myself.* 

* [' Phil. Trans.' 1857, pp. 327-346. L. C. T.] 



1857.J THE LAKE OF GENEVA. 33 



EXPEDITION OF 1857. 

THE LAKE OF GENEVA, 
(4.) 

THE time occupied in the observations of 1856 embraced 
about five whole days ; and though these days were labo- 
rious and instructive, still so short a time proved to be 
wholly incommensurate with the claims of so wide a pro- 
blem. During the subsequent experimental treatment of 
the subject, I had often occasion to feel the incompleteness 
of my knowledge, and hence arose the desire to make a 
second expedition to the Alps, for the purpose of expand- 
ing, fortifying, or, if necessary, correcting first impressions. 

On Thursday, the 9th of July, 1857, 1 found myself upon 
the Lake of Geneva, proceeding towards Vevey. I had 
long wished to see the waters of this renowned inland sea, 
the colour of which is perhaps more interesting to the man 
of science than to the poets who have sung about it. Long 
ago its depth of blue excited attention, but no systematic 
examination of the subject has, so far as I know, been 
attempted. It may be that the lake simply exhibits the 
colour of pure water. Ice is blue, and it is reasonable to 
suppose that the liquid obtained from the fusion of ice is 
of the same colour ; but still the question presses " Is the 
blue of the Lake of Geneva to be entirely accounted for 
in this way ? " The attempts which have been made to 
explain it otherwise show that at least a doubt exists as to 
the sufficiency of the above explanation. 

It is only in its deeper portions that the colour of the 
lake is properly seen. Where the bottom comes into view 
the pure effect of the water is disturbed ; but where the 

D 



34 BLUENESS OF THE WATER. [1857. 

water is deep the colour is deep : between Rolle and 
Nyon for example, the blue is superb. Where the blue 
was deepest, however, it gave me the impression of turbidity 
rather than of deep transparency. At the upper portion of 
the lake the water through which the steamer passed was 
of a blue green. Wishing to see the place where the Rhone 
enters the lake, I walked on the morning of the 10th 
from Villeneuve to Novelle, and thence through the woods 
to the river side. Proceeding along an embankment, 
raised to defend the adjacent land from the incursions of 
the river, an hour brought me to the place where it 
empties itself into the lake. The contrast between the 
two waters was very great : the river was almost white 
with the finely divided matter which it held in suspension ; 
while the lake at some distance was of a deep ultramarine. 

The lake in fact forms a reservoir where the particles 
held in suspension by the river have time to subside, and 
its waters to become pure. The subsidence of course takes 
place most copiously at the head of the lake ; and here 
the deposit continues to form new land, adding year by 
year to the thousands of acres which it has already left 
behind it, and invading more and more the space occupied 
by the water. Innumerable plates of mica spangled the 
fine sand which the river brought down, and these, mixing 
with the water, and flashing like minute mirrors as the sun's 
rays fell upon them, gave the otherwise muddy stream a 
silvery appearance. Had I an opportunity I would make 
the following experiments : 

(a.) Compare the colour of the light transmitted by a 
column of the lake water fifteen feet long with that trans- 
mitted by a second column, of the same length, derived 
from-the melting of freshly fallen mountain snow. 

(b.) Compare in the same manner the colour of the ordi- 
nary water of the lake with that of the same water after 
careful distillation. 



1857.] 



ATMOSPHERIC KEFEACTION. 



35 



(c.) Strictly examine whether the light transmitted by 
the ordinary water contains an excess of red over that 
transmitted by the distilled water : this latter point, as 
will be seen farther on, is one of peculiar interest. 

The length is fixed at fifteen feet, because I have found 
this length extremely efficient in similar experiments. 

On returning to the pier at Villeneuve, a peculiar 
flickering motion was manifest upon the surface of the dis- 
tant portions of the lake, and I soon noticed that the 
coast line was inverted by atmospheric refraction. It 
required a long distance to produce the effect : no trace 
of it was seen about the Castle of Chillon, but at Vevey 
and beyond it, the whole coast was clearly inverted ; and 
the houses on the margin of the lake were also imaged to 
a certain height. Two boats at a considerable distance pre- 
sented the appearance sketched in Figs. 3 and 4 ; the hull 



A 




Fig. 4. 



of each, except a small portion at the end, was invisible, 
but the sails seemed lifted up high in the air, with their 
inverted images below; as the boats drew nearer the 
hulls appeared inverted, the apparent height of the vessel 
above the surface of the lake being thereby nearly doubled, 



36 MIRAGE. [1857. 

while the sails and higher objects, in these cases, were 
almost completely cut away. . When viewed through a 
telescope the sensible horizon of the lake presented a bil- 
lowy tumultuous appearance, fragments being incessantly 
detached from it and suspended in the air. 

The explanation of this effect is the same as that of the 
mirage of the desert, which may be found in almost any 
book on physics, and which so tantalized the French 
soldiers in Egypt. They often mistook this aerial inversion 
for the reflection from a lake, and on trial found hot and 
sterile sand at the place where they expected refreshing 
waters. The effect was shown by Monge, one of the 
learned men who accompanied the expedition, to be due 
to the total reflection of very oblique rays at the upper 
surface of the layer of rarefied air which was nearest to the 
heated earth. A sandy plain, in the early part of the day, 
is peculiarly favourable for the production of such effects ; 
and on the extensive flat strand which stretches between 
Mont St. Michel and the coast adjacent to Avranches in 
Normandy, I have noticed Mont Tombeline reflected as if 
glass instead of sand surrounded it and formed its mirror. 



1857.] CHAMOUNI AND THE MONTANVERT. 37 

CHAMOUNI AND THE MONTANVERT. 
(5.) 

ON the evening of the 12th of July I reached Chamouni ; 
the weather was not quite clear, but it was promising ; 
white cumuli had floated round Mont Blanc during the 
day, but these diminished more and more, and the light of 
the setting sun was of that lingering rosy hue which bodes 
good weather. Two parallel beams of a purple tinge were 
drawn by the shadows of the adjacent peaks, straight across 
the Glacier des Bossons, and the Glacier des Pelerins was 
also steeped for a time in the same purple light. Once 
when the surrounding red illumination was strong, the 
shadows of the Grands Mulets falling upon the adjacent 
snow appeared of a vivid green. 

This green belonged to the class of subjective colours, or 
colours produced by contrast, about which a volume might 
be written. The eye received the impression of green, 
but the colour was not external to the eye. Place a red 
wafer on white paper, and look at it intently, it will be 
surrounded in a little time by a green fringe : move the 
wafer bodily away, and the entire space which it occupied 
upon the paper will appear green. A body may have its 
proper colour entirely masked in this way. Let a red 
wafer be attached to a piece of red glass, and from a 
moderately illuminated position let the sky be regarded 
through the glass ; the wafer will appear of a vivid green. 
If a strong beam of light be sent through a red glass and 
caused to fall upon a screen, which at the same time is 
moderately illuminated by a separate source of white light, 
an opaque body placed in the path of the beam will cast 
a green shadow upon the screen which may be seen by 



38 COLOURED SHADOWS. [1857. 

several hundred persons at once. If a blue glass be used, 
the shadow will be yellow, which is the complementary 
colour to blue. 

When we suddenly pass from open sunlight to a mode- 
rately illuminated room, it appears dark at first, but after 
a little time the eye regains the power of seeing objects dis- 
tinctly. Thus one effect of light upon the eye is to render 
it less sensitive, and light of any particular colour falling 
upon the eye blunts its appreciation of that colour. Let us 
apply this to the shadow upon the screen. This shadow 
is moderately illuminated by a jet of white light; but the 
space surrounding it is red, the effect of which upon 
the eye is to blind it in some degree to the perception of 
red. Hence, when the feeble white light of the shadow 
reaches the eye, the red component of this light is, as it 
were, abstracted from it, and the eye sees the residual 
colour, which is green. A similar explanation applies to 
the shadows of the Grands Mulcts. 

On the 13th of July I was joined by my friend Mr. 
Thomas Hirst, and on the 14th we examined together the 
end of the Mer de Glace. In former times the whole volume 
of the Arveiron escaped from beneath the ice at the 
end of the glacier, forming a fine arch at its place of 
issue. This year a fraction only of the water thus found 
egress ; the greater portion of it escaping laterally from the 
glacier at the summit of the rocks called Les Mottets, down 
which it tumbled in a fine cascade. The vault at the 
end of the glacier was nevertheless respectable, and rather 
tempting to a traveller in search of information regard- 
ing the structure of the ice. Perhaps, however, Nature 
meant to give me a friendly warning at the outset, for, 
while speculating as to the wisdom of entering the cavern, 
it suddenly gave way, and, with a crash which rivalled 
thunder, the roof strewed itself in ruins upon the floor. 

Many years ago I had read with delight Coleridge's 



1857.] SUNEISE AT CHAMOUNI. 89 

poem entitled ' Sunrise in the Valley of Chamouni,' and 
to witness in all perfection the scene described by the poet, 
I waited at Chamouni a day longer than was otherwise 
necessary. On the morning of Wednesday, the 1 5th of July, 
I rose before the sun ; Mont Blanc and his wondrous staff of 
Aiguilles were without a cloud ; eastward the sky was of a 
pale orange which gradually shaded off to a kind of rosy 
violet, and this again blended by imperceptible degrees 
with the deep zenithal blue. The morning star was still 
shining to the right, and the moon also turned a pale face 
towards the rising day. The valley was full of music ; 
from the adjacent woods issued a gush of song, while the 
sound of the Arve formed a suitable bass to the shriller me- 
lody of the birds. The mountain rose for a time cold and 
grand, with no apparent stain upon his snows. Suddenly the 
sunbeams struck his crown and converted it into a boss of 
gold. For some time it remained the only gilded summit 
in view, holding communion with the dawn while all the 
others waited in silence. These, in the order of their 
heights, came afterwards, relaxing, as the sunbeams struck 
each in succession, into a blush and smile. 

On the same day we had our luggage transported to the 
Montanvert, while we clambered along the lateral moraine 
of the glacier to the Chapeau. The rocks alongside the 
glacier were beautifully scratched and polished, and I paid 
particular attention to them, for the purpose of furnishing 
myself with a key to ancient glacier action. The scene 
to my right was one of the most wonderful I had ever wit- 
nessed. Along the entire slope of the Glacier des Bois, the 
ice was cleft and riven into the most striking and fantastic 
forms. It had not yet suffered much from the wasting in- 
fluence of the summer weather, but its towers and minarets 
sprang from the general mass with clean chiselled outlines. 
Some stood erect, others leaned, while the white debris, 
strewn here and there over the srlacier, showed where the 

o 



40 GLACIER DES BOIS. [1857. 

wintry edifices had fallen, breaking themselves to pieces, 
and grinding the masses on which they fell to powder. 
Some of them gave way during our inspection of the place, 
and shook the valley with the reverberated noise of their 
fall. I endeavoured to get near them, but failed ; the 
chasms at the margin of the glacier were too dangerous, and 
the stones resting upon the heights too loosely poised to 
render persistence in the attempt excusable. 

We subsequently crossed the glacier to the Montanvert, 
and I formally took up my position there. The rooms of 
the hotel were separated from each other by wooden 
partitions merely, and thus the noise of early risers in one 
room was plainly heard in the next. For the sake of 
quiet, therefore, I had my bed placed in the chateau next 
door, a little octagonal building erected by some 
kind and sentimental Frenchman, and dedicated " a la 
Nature" My host at first demurred, thinking the place 
not " fyrvpre" but I insisted, and he acquiesced. True the 
stone floor was dark with moisture, and On the walls a 
glistening was here and there observable, which suggested 
rheumatism, and other penalties, but I had had no expe- 
rience of rheumatism, and trusted to the strength which 
mountain air and exercise were sure to give me, for 
power to resist its attacks. Moreover, to dispel some of 
the humidity, it was agreed that a large pine fire should 
be made there on necessary occasions. 

Though singularly favoured on the whole, still our resi- 
dence at the Montanvert was sufficiently long to give us 
specimens of all kinds of weather ; and thus my chateau 
derived an interest from the mutations of external nature. 
Sometimes no breath disturbed the perfect serenity of the 
night, and the moon, set in a black-blue sky, turned a, face 
of almost supernatural brightness to the mountains, while 
in her absence the thick-strewn stars alone flashed and 
twinkled through the transparent air. Sometimes dull 



1857.] QUARTERS AT THE MONTANVERT. 41 

dank fog choked the valley, and heavy rain plashed upon 
the stones outside. On two or three occasions we were 
favoured by a thunderstorm, every peal of which broke 
into a hundred echoes, while the seams of lightning which 
ran through the heavens produced a wonderful intermittence 
of gloom and glare. And as I sat within, musing on the. 
experiences of the day, with my pine logs crackling, and 
the ruddy fire-light gleaming over the walls, and lending 
animation to the visages sketched upon them with charcoal 
by the guides, I felt that my position was in every way 
worth v of a student of nature. 



42 A RIVER OF ICE. [1857. 



THE MEE DE GLACE. 

(6.) 

THE name " Mer de Glace " lias doubtless led many who 
have never seen this glacier to a totally erroneous concep- 
tion of its character. Misled probably by this term, a 
distinguished writer, for example, defines a glacier to be 
a sheet of ice spread out upon the slope of a mountain ; 
whereas the Mer de Glace is indeed a river, and not a sea 
of ice. But certain forms upon its surface, often noticed 
and described, and which I saw for the first time from the 
window of our hotel on the morning of the 16th of July, 
suggest at once the origin of the name. The glacier here 
has the appearance of a sea which, after it had been tossed 
by a storm, had suddenly stiffened into rest. The ridges 
upon its surface accurately resemble waves in shape, and 
this singular appearance is produced in the following 
way : 

Some distance above the Montanvert opposite to the 
Echelets the glacier, in passing down an incline, is rent 
by deep fissures, between each two of which a ridge of 
ice intervenes. At first the edges of these ridges are sharp 
and angular, but they are soon sculptured off by the action 
of the sun. The bearing of the Mer de Glace being 
approximately north and south, the sun at mid-day shines 
down the glacier, or rather very obliquely across it; 
and the consequence is, that the fronts of the ridges, which 
look downward, remain in shadow all the day, while the 
backs of the ridges, which look up the glacier, meet the 
direct stroke of the solar rays. The ridges thus acted 
upon have their hindmost angles wasted off and converted 



1857.] 



FROZEN WAVES. 



43 



into slopes which represent the back of a wave, while the 
opposite sides of the ridges, which are protected from the 
sun, preserve their steepness, and represent the front of the 
wave. Fig. 5 will render my meaning at once plain. 




The dotted lines are intended to represent three of the 
ridges into which the glacier is divided, with their inter- 
posed fissures ; the dots representing the boundaries of the 
ridges when the glacier is first broken. The parallel 
shading lines represent the direction of the sun's rays, 
which, falling obliquely upon the ridges, waste away the 
right-hand corners, and finally produce wave-like forms. 

We spent a day or two in making the general acquaint- 
ance of the glacier. On the 16th we ascended till we came 
to the rim of the Talefre basin, from which we had a good 
view of the glacier system of the region. The lami- 
nated structure of the ice was a point which particularly 
interested me ; and as I saw the exposed sections of the 
neve, counted the lines of stratification, and compared 
these with the lines upon the ends of the secondary 



44 



GLACIER TABLES. 



[1857. 



glaciers, I felt the absolute necessity either of connecting 
the veined structure with the strata by a continuous chain 
of observations, or of proving by ocular evidence that 
they were totally distinct from each other. I was well 
acquainted with the literature of the subject, but nothing 
that I had read was sufficient to prove what I required. 
Strictly speaking, nothing that had been written upon the 
subject rose above the domain of opinion >, while I felt that 
without absolute demonstration the question would never 
be set at rest. 

On this day we saw some fine glacier tables ; flat masses 
of rock, raised high upon columns of ice : Fig. 6 is a 




sketch ol one of the finest of them. Some of them fell 
from their pedestals while we were near them, and the 
clean ice-surfaces which they left behind sparkled with 
minute stars as the small bubbles of air ruptured the film 
of water by which they were overspread. I also noticed that 
" petit bruit de crepitation/ to which M. Agassiz alludes, 
and which he refers to the rupture of the ice by the ex- 



1857.] FIRST SIGHT OF THE DIRT-BANDS. 45 

tnsion of the air-bubbles contained within it. When I 
first read Agassiz's account of it, I thought it might be 
produced by the rupture of the minute air-bubbles which 
incessantly escape from the glacier. This, doubtless, pro- 
duces an effect, but there is something in the character of 
the sound to be referred, I think,- to a less obvious cause, 
which I shall notice further on. 

At six P.M. this day I reached the Montanvert ; and the 
same evening, wrapping my plaid around me, I wandered 
up towards Charmoz, and from its heights observed, as 
they had been observed fifteen years previously by Pro- 
fessor Forbes, the dirt-bunds of the Mer de Glace. They 
were different from any I had previously seen, and I felt 
a strong desire to trace them, to their origin. Content, 
however, with the performance of the day, and feeling 
healthily tired by it, I lay down upon the bilberry bushes 
and fell asleep. It was dark when I awoke, and I experi- 
enced some difficulty and risk in getting down from the 
petty eminence referred to. 

The illumination of the glacier, as remarked by Pro- 
fessor Forbes, has great influence upon the appearance of 
the bands ; they are best seen in a subdued light, and I 
think for the following reasons : 

The dirt-bands are seen simply because they send less 
light to the eye than the cleaner portions of the glacier 
which lie between them ; two surfaces, differently illumi- 
nated, are presented to the eye, and it is found that this 
difference is more observable when the light is that of 
evening than when it is that of noon. 

It is only within certain limits that the eye is able to 
perceive differences of intensity in different lights ; beyond 
a certain intensity, if I may use the expression, light ceases 
to be light, and becomes mere pain. The naked eye can 
detect no difference in brightness between the electric light 



46 BANDS SEEN BEST BY TWILIGHT. [1857. 

and the lime light, although, when we come to strict mea- 
surement, the former may possess many times the inten- 
sity of the latter. It follows from this that we might 
reduce the ordinary electric light to a fraction of its in- 
tensity, without any perceptible change of brightness to 
the naked eye which looks at it. But if we reduce the 
lime light in the same proportion the effect would be very 
different. This light lies much nearer to the limit at which 
the eye can appreciate differences of brightness, and its 
reduction might bring it quite within this limit, and 
make it sensibly dimmer than before. Hence we see 
that when two sources of intense light are presented 
to the eye, by reducing both the lights in the same pro- 
portion, the di/erence between them may become more 
perceptible. 

Now the dirt-bands and the spaces between them re- 
semble, in some measure, the two lights above mentioned. 
By the full glare of noon both are so strongly illuminated 
that the difference which the eye perceives is very small ; 
as the evening advances the light of both is lowered in the 
same proportion, but the differential effect upon the eye 
is thereby augmented, and the bands are consequently 
more clearly seen. 



(7-) 

On Friday, the 17th of July, we commenced our mea- 
surements. Through the kindness of Sir Eoderick Mur- 
chison, I found myself in the possession of an excellent 
five-inch theodolite, an instrument with the use of which 
both my friend Hirst and myself were perfectly familiar. 



1857.] THE CLEFT STATION. 47 

We worked in concert for a few days to familiarize our 
assistant with the mode of proceeding, but afterwards it 
was my custom to simply determine the position where a 
measurement was to be made, and to leave the execu- 
tion of it entirely to Mr. Hirst and our guide. 

On the 20th of July I made a long excursion up the 
glacier, examining the moraines, the crevasses, the struc- 
ture, the moulins, and the disintegration of the surface. 
I was accompanied by a boy named Edouard Balmat,* and 
found him so good an iceman that I was induced to take 
him with me on the following day also. 

Looking upwards from the Montanvert to the left of 
the Aiguille de Charrnoz, a singular gap is observed in 
the rocky mountain wall, in the centre of which stands a 
detached column of granite. Both cleft and pillar are 
shown in. the frontispiece, to the right. The eminence to 
the left of this gap is signalised by Professor Forbes as one 
of the best stations from which to view the Mer de Glace, 
and this point, which I shall refer to hereafter as the Cleft 
Station, it was now my desire to attain. From the Mon- 
tanvert side a steep gully leads to the cleft; up this 
couloir we proposed to try the ascent. At a considerable 
height above the Mer de Glace, and closely hugging 
the base of the Aiguille de Charm oz, is the small Gla- 
cier de Tendue, shown in the frontispiece, and from 
which a steep slope stretches down to the Mer de Glace. 
This Tendue is the most talkative glacier I have ever 
known ; the clatter of the small stones which fall from it 
is incessant. Huge masses of granite also frequently fall 
upon the glacier from the cliffs above it, and, being slowly 
borne downwards by the moving ice, are at length seen 
toppling above the terminal face of the glacier. The 
> ice which supports them being gradually melted, they are 
* " Le petit Balmat " my host always called him. 



48 KOUGH ASCENT. [1857. 

at length undermined, and sent bounding down the slope 
with peal and rattle, according as the masses among which 
they move are large or small. The space beneath the 
glacier is cumbered with blocks thus sent clown ; some of 
them of enormous size. 

The danger arising from this intermittent cannonade, 
though in reality small, has caused the guides to swerve 
from the path which formerly led across the slope to the 
promontory of Trelaporte. I say " small," because, even 
should a rock choose the precise moment at which a tra- 
veller is passing to leap down, the boulders at hand are so 
large and so capable of bearing a shock that the least 
presence of mind would be sufficient to place him in safety. 
But presence of mind is not to be calculated on under 
such circumstances, and hence the guides were right to 
abandon the path. 

Reaching the mouth of our gully after a rough ascent, 
we took to the snow, instead of climbing the adjacent 
rocks. It was moist and soft, in fact in a condition alto- 
gether favourable for the "regelation" of its granules. 
As the foot pressed upon it the particles became cemented 
together. A portion of the pressure was transmitted 
laterally, which produced attachments beyond the bound- 
ary of the foot ; thus as the latter sank, it pressed upon 
a surface which became continually wider and more rigid, 
and at length sufficiently strong to bear the entire 
weight of the body ; the pressed snow formed in fact a 
virtual camel's foot, which soon placed a limit to the sink- 
ing. It is this same principle of regelation which enables 
men to cross snow bridges in safety. By gentle cautious 
pressure the loose granules of the substance are cemented 
into a continuous mass, all sudden shocks which might 
cause the frozen surfaces to snap asunder being avoided. 
In this way an arch of snow fifteen or twenty inches in 



1857.] CHAMOIS ON THE MOUNTAINS. 49 

thickness may be rendered so firm that a man will cross 
it, although it may span a chasm one hundred feet in 
depth. 

As we ascended, the incline became very steep, and 
once or twice we diverged from the snow to the adjacent 
rocks ; these were disintegrated, and the slightest dis- 
turbance was sufficient to bring them down ; some fell, 
and from one of them I found it a little difficult to escape ; 
for it grazed my leg, inflicting a slight wound as it passed. 
Just before reaching the cleft at which we aimed, the snow 
for a short distance was exceedingly steep, but we sur- 
mounted it ; and I sat for a time beside the granite pillar, 
pleased to find that I could permit my legs to dangle over 
a precipice without prejudice to my head. 

While we remained here a chamois made its appear- 
ance upon the rocks above us. Deeming itself too near, 
it climbed higher, and then turned round to watch us. 
It was soon joined by a second, and the two formed a 
very pretty picture : their attitudes frequently changed, 
but they were always graceful; with head erect and 
horns curved back, a light limb thrown forward upon a 
ledge of rock, looking towards us with wild and earnest 
gaze, each seemed a type of freedom and agility. 
Turning now to the left, we attacked the granite tower, 
from which we purposed to scan the glacier, and were 
soon upon its top. My companion was greatly pleased 
he was " tres-content " to have reached the place he 
felt assured that many old guides would have retreated 
from that ugly gully, with its shifting shingle and debris, 
and his elation reached its climax in the declaration that, 
if I resolved to ascend Mont Blanc without a guide, he 
was willing to accompany me. 

From the position which we had attained, the prospect 
was exceedingly fine, both of the glaciers and of the 
mountains. Beside us was the Aiguille de Charmoz, 

E 



50 SCENE FKOM THE STATION. [1857. 

piercing with its spikes of granite the clear air. To my 
mind it is one of the finest of the Aiguilles, noble in mass, 
with its summits singularly cleft and splintered. In some 
atmospheric colourings it has the exact appearance of a 
mountain of cast copper, and the manner in which some of 
its highest pinnacles are bent, suggesting the idea of ducti- 
lity, gives strength to the illusion that the mass is metallic. 
At the opposite side of the glacier was the Aiguille Verte, 
with a cloud poised upon its point : it has long been the 
ambition of climbers to scale this peak, and on this day it 
was attempted by a young French count with a long 
retinue of guides. He had not fair play, for before we 
quitted our position we heard the rumble of thunder upon 
the mountain, which indicated the presence of a foe more 
terrible than the avalanches themselves. Higher to the 
right, and also at the opposite side of the glacier, rose the 
Aiguille du Moine; and beyond was the basin of the 
Talefre, the ice cascade issuing from which appeared, from 
our position, like the foam of a waterfall. Then came the 
Aiguille de Lechaud, the Petite Jorasse, the Grande Jorasse, 
and the Mont Tacul ; all of which form a cradle for the 
Glacier de Lechaud. Mont Mallet, the Periades, and the 
Aiguille Noire, came next, and then the singular obelisk of 
the Aiguille du Geant, from which a serrated edge of 
cliff descends to the summit of the " Col." 

Over the slopes of the Col du Geant was spread a cover- 
let of shining snow, at some places apparently as smooth 
as polished marble, at others broken so as to form pre- 
cipices, on the pale blue faces of which the horizontal lines 
of bedding were beautifully drawn. As the eye approaches 
the line which stretches from the Rognon to the Aiguille 
Noire, the repose of the neve becomes more and more dis- 
turbed. Vast chasms are formed, which however are still 
merely indicative of the trouble in advance. If the gla- 
cier were lifted off we should probably see that the line 



1857.] SEKACS OF THE COL DU GEANT. 51 

just referred to would lie along the summit of a steep 
gorge ; over this summit the glacier is pushed, and has its 
back periodically broken, thus forming vast transverse 
ridges which follow each other in succession down the slope. 
At the summit these ridges are often cleft by fissures 
transverse to them, thus forming detached towers of ice of 
the most picturesque and imposing character.* These 
towers often fall ; and while some are caught upon the 
platforms of the cascade, others struggle with the slow 
energy of a behemoth through the debris which opposes 
them, reach the edges of the precipices which rise in suc- 
cession along the fall, leap over, and, amid ice-smoke and 
thunder-peals, fight their way downwards. 

A great number of secondary glaciers were in sight 
hanging on the steep slopes of the mountains, and from 
them streams sped downwards, falling over the rocks, and 
filling the valley with a low rich music. In front of me, 
for example, was the Glacier du Moine, and I could not 
help feeling as I looked at it, that the arguments drawn 
from the deportment of such glaciers against the " sliding 
theory," and which are still repeated in works upon the 
Alps, militate just as strongly against the " viscous theory." 
" How," demands the antagonist of the sliding theory, 
" can a secondary glacier exist upon so steep a slope ? why 
does it not slide down as an avalanche ? " " But how," the 
person addressed may retort, " can a mass which you as- 
sume to be viscous exist under similar conditions ? If it be 
viscous, what prevents it from rolling down ? " The sliding 
theory assumes the lubrication of the bed of the glacier, 
but on this cold height the quantity melted is too small 

* To such towers the name Seracs is applied. In the chalets of Savoy, 
after the richer curd has been precipitated by rennet, a stronger acid is 
used to throw down what remains ; an inferior kind of cheese called Sdrac 
is thus formed, the shape and colour of which have suggested the applica- 
tion of the term to the cubical masses of ice. 

E 2 



52 GLACIEK MOTION. [1857. 

to lubricate the bed, and hence the slow motion of these 
glaciers. Thus a sliding-theory man might reason, and, if 
the external deportment of secondary glaciers were to de- 
cide the, question, De Saussure might perhaps have the 
best of the argument. 

And with regard to the current idea, originated by M. 
de Charpentier, and adopted by Professor Forbes, that if a 
glacier slides it must slide as an avalanche, it may be 
simply retorted that, in part, it does so ; but if it be asserted 
that an accelerated motion is the necessary motion of an 
avalanche, the statement needs qualification. An avalanche 
on passing through a rough couloir soon attains a uni- 
form velocity its motion being accelerated only up to the 
point when the sum of the resistances acting upon it is 
equal to the force drawing it downwards. These resistances 
are furnished by the numberless asperities which the mass 
encounters, and which incessantly check its descent, and 
render an accumulation of motion impossible. The motion 
of a man walking down stairs may be on the whole uniform, 
but it is really made up of an aggregate of small motions, 
each of which is accelerated ; and it is easy to conceive 
how a glacier moving over an uneven bed, when released 
from one opposing obstacle will be checked by another, and 
its motion thus rendered sensibly uniform. 

From the Aiguille du Geant and Les Periades a glacier 
descended, which was separated by the promontory of La 
Noire from the glacier proceeding from the Col du Geant. 
A small moraine was formed between them, which is marked 
a upon the diagram, Fig. 7. The great mass of the glacier 
descending from the Col du Geant came next, and this was 
bounded on the side nearest to Trelaporte by a small 
moraine ft, the origin of which I could not see, its upper 
portion being shut out by a mountain promontory. Between 
the moraine b and the actual side of the valley was another 
little glacier, derived from some of the lateral tributaries. 



1857.] 



MOKAINES. 



It was, however, between the moraines a and b that the 
great mass of the Glacier du Geant really lay. At the 




Fig. 7. 

promontory of the Tacul the lateral moraines of the Gla- 
cier des Periades and of the Glacier de Lechaud united to 



54 TKIBUTAEIES OF THE MER DE GLACE. [1857. 

form the medial moraine c of the Mer de Glace. Carry- 
ing the eye across the Lechaud, we had the moraine d 
formed by the union of the lateral moraines of the Lechaud 
and Talefre ; further to the left was the moraine e, which 
came from the Jardin, and beyond it was the second lateral 
moraine of the Talefre. The Mer de Glace is formed by 
the confluence of the whole of the glaciers here named ; 
being forced at Trelaporte through a passage, the width of 
which appears considerably less than that of the single 
tributary, the Glacier du Geant. 

In the ice near Trelaporte the blue veins of the glacier 
are beautifully shown ; but they vary in distinctness accord- 
ing to the manner in which they are looked at. When 
regarded obliquely their colour is. not so pronounced as 
when the vision plunges deeply into them. The weathered 
ice of the surface near Trelaporte could be cloven with great 
facility ; I could with ease obtain plates of it a quarter of 
an inch thick, and possessing two square feet of surface. On 
the 28th of July I followed the veins several times from 
side to side across the Geant portion of the Mer de Glace ; 
starting from one side, and walking along the veins, my 
route was directed obliquely downwards towards the axis 
of the tributary. At the axis I was forced to turn, in 
order to keep along the veins, and now ascended along 
a line which formed nearly the same angle with the axis 
at the other side. Thus the veins led me as it were 
along the two sides of a triangle, the vertex of which was 
near the centre of the glacier. The vertex was, however, 
in reality rounded off, and the figure rather resembled a 
hyperbola, which tended to coincidence with its asymp- 
totes. This observation corroborates those of Professor 
Forbes with regard to the position of the veins, and, like 
him, I found that at the centre the veining, whose normal 
direction would be transverse to the glacier, was contorted 
and confused. 



1857.] WASTING O.F ICE. 55 

Near the side of the Glacier du Geant 3 above the pro- 
montory of Trelaporte, the ice is rent in a remarkable 
manner. Looking upwards from the lower portions of the 
glacier, a series of vertical walls, rising apparently one 
above the other, face the observer. I clambered up among 
these singular terraces, and now recognise, both from my 
sketch and memory, that their peculiar forms are due to 
the same action as that which has given their shape to the 
" billows " of the Mer de Glace. A series of profound 
crevasses is first formed. The Glacier du Geant deviates 
14 from the meridian line, and hence the sun shines 
nearly down it during the middle portion of each day. 
The backs of the ridges between the crevasses are thus 
rounded off, one boundary of each fissure is destroyed, or 
at least becomes a mere steep declivity, while the other 
boundary being shaded from the sun preserves its ver- 
ticality ; and thus a very curious series of precipices is 
formed. 

Through all this dislocation, the little moraine on 
which I have placed the letter b in the sketch maintains 
its right to existence, and under it the laminated struc- 
ture of this portion of the glacier appears to reach its 
most perfect development. The moraine was generally 
a mere dirt track, but one or two immense blocks of 
granite were perched upon it. I examined the ice under- 
neath one of these, being desirous of seeing whether the 
pressure resulting from its enormous weight would pro- 
duce a veining, but the result was not satisfactory. 
Veins were certainly to be seen in directions different 
from the normal ones, but whether they were due to 
the bending of the latter, or were directly owing to the 
pressure of the block, I could not say. The sides of a 
stream which had cut a deep gorge in the clean ice 
of the Glacier du Geant afforded a fine opportunity of 
observing the structure. It was very remarkable highly 



56 GEOOVES ON THE SURFACE. [1857. 

significant indeed in a theoretic point of view. Two long 
and remarkably deep blue veins traversed the bottom of 
the stream, and bending upwards at a place where the 
rivulet curved, drew themselves like a pair of parallel lines 
upon the clean white ice. But the general structure was 
of a totally different character ; it did not consist of long 
bars, but approximated to the lenticular form, and was, 
moreover, of a washy paleness, which scarcely exceeded in 
depth of colouring the whitish ice around. 

To the investigator of the structure nothing can be Hner 
than the appearance of the glacier from one of the ice 
terraces cut in the Glacier du Geant by its passage round 
Trelaporte. As far as the vision extended the dirt upon 
the surface of the ice was arranged in striae. These striae 
were not always straight lines, nor were they unbroken 
curves. Within slight limits the various parts into which 
a glacier is cut up by its crevasses enjoy a kind of inde- 
pendent motion. The grooves, for example, on two ridges 
which have been separated by a small fissure, may one 
day have their striae perfect continuations of each other, 
but in a short time this identity of direction may be 
destroyed by a, difference of motion between the ridges. 
Thus it is that the grooves upon the surface above Trela- 
porte are bent hither and thither, a crack or seain always 
marking the point where their continuity is ruptured. 
This bending occurs, however, within limits sufficiently 
small to enable the striae to preserve the same genera] 
direction. 

My attention had often been attracted this day by pro- 
jecting masses of what at first appeared to be pure white 
snow, rising in seams above the general surface of the 
glacier. On examination, however, I found them to be 
compact ice, filled with innumerable air-cells, and so 
resistant as to maintain itself in some places at a height of 
four feet above the general level. When amongst the 



1857.] SEAMS OF WHITE ICE. 57 

ridges they appeared discontinuous and confused, being 
scattered apparently at random over the glacier ; but when 
viewed from a sufficient distance, the detached parts 
showed themselves to belong to a system of white seams 
which swept quite across the Glacier du Geant, in a direc- 
tion concentric with the structure. Unable to account for 
these singular seams, I climbed up among the tributary 
glaciers on the Rognon side of the Glacier du Geant, and 
remained there until the sun sank behind the neighbour- 
ing peaks, and the fading light warned me that it was 
time to return. 



(8.) 

Early on the following day I was again upon the ice. 
I first confined myself to the right side of the Glacier du 
Geant, and found that the veins of white ice which I had 
noticed on the previous day were exclusively confined to 
this glacier, or to the space between the moraines a and 
I (Fig. 7), bending up so that the moraine a between 
the Glacier du Geant and the Glacier des Periades was 
tangent to them. At a good distance up the glacier I 
encountered a considerable stream rushing across it 
almost from side to side. I followed the rivulet, examin- 
ing the sections which it exposed. At a certain point 
three other streams united, and formed at their place 
of confluence a small green lake. From this a rivulet 
rushed, which was joined by the stream whose track I had 
pursued, and at this place of junction a second green lake 
was formed, from which flowed a stream equal in volume 
to the sum of all the tributaries. It entered a crevasse, 
and took the bottom of the fissure for its bed. Standing 
at the entrance of the chasm, a low muffled thunder 



58 A LAKE SET FREE. [1857. 

resounding through the valley attracted my attention. I 
followed the crevasse, which deepened and narrowed, and, 
by the blue light of the ice, could see the stream gam- 
bolling along its bottom, and flashing as it jumped over 
the ledges which it encountered in its way. The fissure 
at length came to an end : placing a foot on each side 
of it, and withholding the stronger light from my eyes, 
I looked down between its shining walls, and saw the 
stream plunge into a shaft which carried it to the bottom 
of the glacier. 

Slowly, and in zigzag fashion, as the crevasses demanded, 
I continued to ascend, sometimes climbing vast humps of 
ice from which good views of the surrounding glacier 
were obtained ; sometimes hidden in the hollows between 
the humps, in which also green glacier tarns were often 
formed, very lonely and very beautiful. 

While standing beside one of these, and watching the 
moving clouds which it faithfully mirrored, I heard the 
sound of what appeared to be a descending avalanche, but 
the time of its continuance surprised me. Looking through 
my opera-glass in the direction of the sound, I saw issuing 
from the end of a secondary glacier on the Tacul side a tor- 
rent of what appeared to me to be stones and mud. I could 
see the stones and finer debris jumping down the declivi- 
ties, and shaping themselves into singular cascades. The 
noise continued for a quarter of an hour, after which the 
torrent rapidly diminished, until, at length, the ordinary 
little stream due to the melting of the glacier alone 
remained. A subglacial lake had burst its boundary, and 
carried along with it in its rush downwards the debris 
which it met with in its course. 

In some places I found the crevasses difficult, the ice 
being split in a very singular manner. Vast plates of 
it not more than a foot in thickness were sometimes de- 
tached from the sides of the crevasses, and stood alone. 



1857.] IMPEESSIVE SCENE. 59 

I was now approaching the base of the seracs, and the 
glacier around me still retained a portion of the turbu- 
lence of the cascade. I halted at times amid the ruin and 
confusion, and examined with my glass the cascade itself. 
It was a wild and wonderful scene, suggesting throes of 
spasmodic energy, though, in reality, all its dislocation had 
been sloidij and gradually produced. True, the stratified 
blocks which here and there cumbered the terraces sug- 
gested debacles, but these were local and partial, and did 
not affect the general question. There is scarcely a case 
of geological disturbance which could not be matched with 
its analogue upon the glaciers, contortions, faults, fissures, 
joints, and dislocations, but in the case of the ice we can 
prove the effects to be due to slowly-acting causes; how 
reasonable is it then to ascribe to the operation of similar 
causes, which have had an incomparably longer time to 
work, many geological effects which at first sight might 
suggest sudden convulsion ! 

Wandering slowly upwards, successive points of attrac- 
tion drawing me almost unconsciously on, I found myself 
as the day was declining deep in the entanglements of the 
ice. A shower commenced, and a splendid rainbow threw 
an oblique arch across the glacier. I was quite alone ; the 
scene was exceedingly impressive, and the possibility of 
difficulties on which I had not calculated intervening 
between me and the lower glacier, gave a tinge of 
anxiety to my position. I turned towards home ; crossed 
some bosses of ice and rounded others : I followed the 
tracks of streams which were very irregular on this portion 
of the glacier, bending hither and thither, rushing through 
deep-cut channels, falling in cascades and expanding here 
and there to deep green lakes ; they often plunged into the 
depths of the ice, flowed under it with hollow gurgle, and 
reappeared at some distant point. I threaded my way 
cautiously amid systems of crevasses, scattering with my 



60 CHAMOUNI RULES. [1857. 

axe, to secure a footing, the rotten ice of the sharper crests, 
which fell with a ringing sound into the chasms at either 
side. Strange subglacial noises were sometimes heard, 
as if caverns existed underneath, into which blocks of 
ice fell at intervals, transmitting the shock of their fall 
with a dull boom to the surface of the glacier. By the 
steady surmounting ot difficulties one after another, I at 
length placed them all behind me, and afterwards hastened 
swiftly along the glacier to my mountain home. 

On the 30th incessant rain confined us to indoor work ; 
on the 31st we determined the velocity with which the 
glacier is forced through the entrance of the trunk valley 
at Trelaporte, and also the motion of the Grand Moulin. 
We also determined both the velocity and the width of the 
Glacier du Geant. The 1st of August was spent by me at the 
cascade of the Talefre, examining the structure, crumpling, 
and scaling off of the ice. Finding that the rules at Cha- 
mouni put an unpleasant limit to my demands on my 
guide Simond, I visited the Guide Chef on the 2nd of 
August, and explained to him the object of my expedition, 
pointing out the inconvenience which a rigid application 
of the rules made for tourists would impose upon me. 
He had then the good sense to acknowledge the reason- 
ableness of my remarks, and to grant me the liberty I 
requested. The 3rd of August was employed in deter- 
mining the velocity and width of the Glacier de Lech and, 
and in observations on the lamination of the glacier. 



1857.] THE JARDIN. 61 



THE JARDIN. 



ON the 4th of August, with a view of commencing a 
series of observations on the inclinations of the Mer de 
Glace and its tributaries, we had our theodolite transported 
to the Jardin, which, as is well known, lies like an island 
in the middle of the Glacier du Talefre. We reached the 
place by the usual route, and found some tourists reposing 
on the soft green sward which covers the lower portion, and 
to which, and the flowers which spangle it, the place owes its 
name. Towards the summit of the Jardin, a rock jutted 
forward, apparently the very apex of the place, or at least 
hiding by its prominence everything that might exist be- 
hind it ; leaving our guide with the instrument, we aimed 
at this, and soon left the grass and flowers behind us. 
Stepping amid broken fragments of rock, along slopes of 
granite, with fat felspar crystals which gave the boots a 
hold, and crossing at intervals patches of snow, which 
continued still to challenge the summer heat, I at length 
found myself upon the peak referred to ; and, although it 
was not the highest, the unimpeded view which it com- 
manded induced me to get astride it. The Jardin was com- 
pletely encircled by the ice of the glacier, and this was 
held in a mountain basin, which was bounded all round 
by a grand and cliffy rim. The outline of the dark brown 
crags a deeply serrated and irregular line was forcibly 
drawn against the blue heaven, and still more strongly 
against some white and fleecy clouds which lay here and 
there behind it ; while detached spears and pillars of 
rock, sculptured by frost and lightning, stood like a kind of 
defaced statuary along the ridge. All round the basin the 



62 A EESEEVOIK OF ICE. [1857. 

snow reared itself like a buttress against the precipitous 
cliffs, being streaked and fluted by the descent of blocks 
from the summits. This mighty tub is the collector of one 
of the tributaries of the Mer de Glace. According to Pro- 
fessor Forbes, its greatest diameter is 4200 yards, and out 
of it the half-formed ice is squeezed through a precipitous 
gorge about 700 yards wide, forming there the ice cascade 
of the Talefre. Bounded on one side by the Grande 
Jorasse, and on the other by Mont Mallet, the principal 
tributary of the Glacier de Lechaud lay white and pure 
upon the mountain slope. Bound further to the right we 
had the vast plateau whence the Glacier du Geant is fed, 
fenced on the left by the Aiguille du Geant and the 
Aiguille Noire, and on the right by the MontsMaudits and 
Mont Blanc. The scene was a truly majestic one. The 
mighty Aiguilles piercing the sea of air, the soft white 
clouds floating here and there behind them ; the shining 
snow with its striped faults and precipices ; the deep blue 
firmament overhead ; the peals of avalanches and the 
sound of water ; all conspired to render the scene glori- 
ous, and our enjoyment of it deep. 

A voice from, above hailed me as I moved from my 
perch ; it was my friend, who had found a lodgment 
upon the edge of a rock which was quite detached from 
the Jardin, being the first to lift its head in opposition to 
the descending neve. Making a detour round a steep 
concave slope of the glacier, I reached the flat summit of 
the rock. The end of a ridge of ice abutted against it, 
which was split and bent by the pressure so as to form a 
kind of arch. I cut steps in the ice, and ascended until I got 
beneath the azure roof. Innumerable little rills of pellucid 
water descended from it. Some came straight down, clear 
for a time, and apparently motionless, rapidly tapering at 
first, and more slowly afterwards, until, at the point of maxi- 
mum contraction, they resolved themselves into strings of 



1857.] MOEAINES OF THE TALEFKE. 63 

liquid pearls which pattered against the ice floor under- 
neath. Others again, owing to the directions of the little 
streamlets of which they were constituted, formed spiral 
figures of great beauty : one liquid vein wound itself round 
another, forming a spiral protuberance, and owing to the 
centrifugal motion thus imparted, the vein, at its place 
of rupture, scattered itself laterally in little liquid 
spherules.* Even at this great elevation the structure of 
the ice was fairly developed, not with the sharpness to be 
observed lower down, but still perfectly decided. Blue 
bands crossed the ridge of ice to which I have referred, 
at right angles to the direction of the pressure. 

I descended, and found my friend beneath an over- 
hanging rock. Immediately afterwards a peal like that 
of thunder shook the air, and right in front of us an 
avalanche darted down the brown cliffs, then along a steep 
slope of snow which reared itself against the mountain wall, 
carrying with it the debris of the rocks over which it 
passed, until it finally lay a mass of sullied rubbish at the 
base of the incline : the whole surface of the Talefre is 
thus soiled. Another peal was heard immediately after- 
wards, but the avalanche which caused it was hidden 
from us by a rocky promontory. From this same pro- 
montory the greater portion of the medial moraine which 
descends the cascade of the Talefre is derived, forming 
at first a gracefully winding curve, and afterwards stretch- 
ing straight to the summit of the fall. In the chasms of 
the cascade its boulders are engulfed, but the lost moraine 
is restored below the fall, as if disgorged by the ice which 
had swallowed it. From the extremity of the Jardin itself 
a mere driblet of a moraine proceeds, running parallel to 
the former, and like it disappearing at the summit of the 
cascade. 

* The recent hydraulic researches of Professor Magnus furnish some 
beautiful illustrations of this action. 



64 AMONG THE CREVASSES. [1857. 

We afterwards descended towards the cascade, but long 
before this is attained the most experienced iceman would 
find himself in difficulty. Transverse crevasses are formed, 
which follow each other so speedily as to leave between 
them mere narrow ridges of ice, along which we moved 
cautiously, jumping the adjacent fissures, or getting round 
them, as the case demanded. As we approached the jaws 
of the gorge, the ridges dwindled to mere plates and wedges, 
which being bent and broken by the lateral pressure, added 
to the confusion, and warned us not to advance. The 
position was in some measure an exciting one. Our guide 
had never been here before ; we were far from the beaten 
track, and the riven glacier wore an aspect of treacherous 
hostility. As at the base of the semes, a subterranean 
noise sometimes announced the falling of ice-blocks into 
hollows underneath, the existence of which the resonant 
concussion of the fallen mass alone revealed. There was 
thus a dash of awe mingled with our thoughts ; a stirring 
up of the feelings which troubled the coolness of the intel- 
lect. We finally swerved to the right, and by a process 
the reverse of straightforward reached the Couvercle. 
Nightfall found us at the threshold of our hotel. 



(10.) 

On the 5th we were engaged for some time in an im- 
portant measurement at the Tacul. We afterwards ascended 
towards the seracs, and determined the inclinations of the 
Glacier du Geant downwards. Dense cloud-masses gathered 
round the points of the Aiguilles, and the thunder bellowed 
at intervals from the summit of Mont Blanc. As we de- 
scended the Mer de Glace the valley in front of us was 
filled with a cloud of pitchy darkness. Suddenly from side 



1857.] ROUND HAILSTONES. 65 

to side this field of gloom was riven by a bar of light- 
ning of intolerable splendour ; it was followed by a peal of 
commensurate grandeur, the echoes of which leaped from 
cliff to cliff long after the first sound had died away. The 
discharge seemed to unlock the clouds above us, for they 
showered their liquid spheres down upon us with a mo- 
mentum like that of swan-shot : all the way home we were 
battered by this pellet-like rain. On the 6th the rain con- 
tinued with scarcely any pause ; on the 7th I was engaged 
all day upon the Glacier du Geant ; on the morning of the 
8th heavy hail had fallen there, the stones being perfect 
spheres ; the rounded rain-drops had solidified during then* 
descent without sensible change of form. When this hail 
was squeezed together, it exactly resembled a mass of 
oolitic limestone which I had picked up in 1853 near 
Blankenburg in the Hartz. Mr. Hirst and myself were en- 
gaged together this day taking the inclinations : he struck 
his theodolite at the Angle, and went home accompanied 
by Simond, and the evening being extremely serene, I pur- 
sued my way down the centre of the glacier towards the 
Echelets. The crevasses as I advanced became more 
deep and frequent, the ridges of ice between them becom- 
ing gradually narrower. They were very fine, their down- 
ward faces being clear cut, perfectly vertical, and in many 
cases beautifully veined. Vast plates of ice moreover 
often stood out midway between the walls of the chasms, 
as if cloven from the glacier and afterwards set on edge. 
The place was certainly one calculated to test the skill 
and nerve of an iceman; and as the day drooped, and 
the shadow in the valley deepened, a feeling approach- 
ing to awe took possession of me. My route was an exag- 
gerated zigzag ; right and left amid the chasms wherever 
a hope of progress opened ; and here I made the experience 
which I have often repeated since, and laid to heart as 
regards intellectual work also, that enormous difficulties 

F 



66 A DANGEROUS LEAP. [1857. 

may be overcome when they are attacked in earnest. 
Sometimes I found myself so hedged in by fissures that 
escape seemed absolutely impossible ; but close and resolute 
examination so often revealed a means of exit, that I felt 
in all its force the brave verity of the remark of Mirabeau, 
that the word " impossible " is a mere blockhead of a word. 
It finally became necessary to reach the shore, but I found 
this a work of extreme difficulty. At length, however, it be- 
came pretty evident that, if I could cross a certain crevasse, 
my retreat would be secured. The width of the fissure 
seemed to be fairly within jumping distance, and if I could 
have calculated on a safe purchase for my foot I should 
have thought little of the spring ; but the ice on the edge 
from which I was to leap was loose and insecure, and hence 
a kind of nervous thrill shot through me as I made the 
bound. The opposite side was fairly reached, but an invo- 
luntary tremor shook me all over after I felt myself secure. 
I reached the edge of the glacier without further serious 
difficulty, and soon after found myself steeped in the crea- 
ture comforts of our hotel. 

On Monday, August 10th, I had the great pleasure of 
being joined by my friend Huxley ; and though the weather 
was very unpromising, we started together up the glacier, 
he being desirous to learn something of its general features, 
and, if possible, to reach the Jardin. We reached the 
Couvercle, and squeezed ourselves through the Egralets ; 
but here the rain whizzed past us, and dense fog settled 
upon the cascade of the Talefre, obscuring all its parts. 
We met Mr. Galton, the African traveller, returning 
from an attempt upon the Jardin ; and learning that his 
guides had lost their way in the fog, we deemed it prudent 
to return. 

The foregoing brief notes will have informed the reader 
that at the period of Mr. Huxley's arrival I was not with- 
out due training upon the ice ; I may also remark, that on 



1857.] PKEPAKATIONS FOR A CLIMB. 67 

the 25th of July I reached the sum-rait of the Col du 
Geant, accompanied by the boy Balmat, and returned to 
Montanvert on the same day. My health was perfect, 
and incessant practice had taught me the art of dealing 
with the difficulties of the ice. From the time of my 
arrival at the Montanvert the thought of ascending Mont 
Blanc, and thus expanding my knowledge of the glaciers, 
had often occurred to me, and I think I was justified in 
feeling that the discipline which both my friend Hirst 
and myself had undergone ought to enable us to accom- 
plish the journey in a much more modest way than ordi- 
nary. I thought a single guide sufficient for this purpose, 
and I was strengthened in this opinion by the fact that 
Simond, who was a man of the strictest prudence, and who 
at first declared four guides to be necessary, had lowered 
his demand first to two, and was now evidently willing to 
try the ascent with us alone. 

On mentioning the thing to Mr. Huxley he at once 
resolved to accompany us. On the llth of August the 
weather was exceedingly fine, though the snow which had 
fallen during the previous days lay thick upon the glacier. 
At noon we were all together at the Tacul, and the subject 
of attempting Mont Blanc was mooted and discussed. My 
opinion was that it would be better to wait until the fresh 
snow which loaded the mountain had- disappeared ; but the 
weather was so exquisite that my friends thought it best to 
take advantage of it. We accordingly entered into an 
agreement with our guide, and immediately descended to 
make preparations for commencing the expedition on the 
following morning. 



F 2 



68 SCENE FEOM THE CHARMOZ. [1857. 

FIRST ASCENT OF MONT BLANC, 1857. 

(11.) 

ON Wednesday, the 12th of August, we rose early, after a 
very brief rest on my part. Simond had proposed to go down 
to Chamouni, and commence the ascent in the usual way, 
but we preferred crossing the mountains from the Montan - 
vert, straight to the Glacier des Bossons. At eight o'clock 
we started, accompanied by two porters who were to carry 
our provisions to the Grands Mulets. Slowly and silently 
we climbed the hill-side towards Charmoz. We soon 
passed the limits of grass and rhododendrons, and reached 
the slabs of gneiss which overspread the summit of the 
ridge, lying one upon the other like coin upon the table of 
a money-changer. From the highest point I turned to 
have a last look at the Mer de Glace ; and through a pair 
of very dark spectacles I could see with perfect distinct- 
ness the looped dirt-bands of the glacier, which to the 
naked eye are scarcely discernible except by twilight. 
Flanking our track to the left rose a series of mighty 
Aiguilles the Aiguille de Charmoz, with its bent and 
rifted pinnacles ; the Aiguille du Grepon, the Aiguille de 
Blaitiere, the Aiguille du Midi, all piercing the heavens 
with their sharp pyramidal summits. Far in front of us 
rose the grand snow-cone of the Dome du Gouter, while, 
through a forest of dark pines which gathered like a 
cloud at the foot of the mountain, gleamed the white 
minarets of the Glacier des Bossons. Below us lay the 
Valley of Chamouni, beyond which were the Brevent and 
the chain of the Aiguilles Rouges ; behind us was the 
granite obelisk of the Aiguille du Dru, while close at hand 
science found a corporeal form in a pyramid of stones 



1857.] PASSAGE TO THE PIEERE A L'ECHELLE. 69 

used as a trigonometrical station by Professor Forbes. 
Sound is known to travel better up hill than down, be- 
cause the pulses transmitted from a denser medium to a 
rarer, suffer less loss of intensity than when the transmis- 
sion is in the opposite direction ; and now the mellow voice 
of the Arve came swinging upwards from the heavier air 
of the valley to the lighter air of the hills in rich deep 
cadences. 

The way for a time was excessively rough, our route 
being overspread with the fragments of peaks which had 
once reared themselves to our left, but which frost and 
lightning had shaken to pieces, and poured in granite 
avalanches down the mountain. We were sometimes 
among huge angular boulders, and sometimes amid lighter 
shingle, which gave way at every step, thus forcing us 
to shift our footing incessantly. Escaping from these, we 
crossed the succession of secondary glaciers which lie at 
the feet of the Aiguilles, and having secured firewood 
found ourselves after some hours of hard work at the 
Pierre a 1'Echelle. Here we were furnished with leggings 
of coarse woollen cloth to keep out the snow ; they were 
tied under the knees and quite tightly again over the 
insteps, so that the legs were effectually protected. We 
had some refreshment, possessed ourselves of the ladder, 
and entered upon the glacier. 

The ice was excessively fissured : we crossed crevasses 
and crept round slippery ridges, cutting steps in the ice 
wherever climbing was necessary. This rendered our pro- 
gress very slow. Once, with the intention of lending a 
helping hand, I stepped forward upon a block of granite 
which happened to be poised like a rocking stone upon the 
ice, though I did not know it; it treacherously turned 
under me ; I fell, but my hands were in instant requisition, 
and I escaped with a bruise, from which, however, the 
blood oozed angrily. We found the ladder necessary in 



70 LADDER LEFT BEHIND. [1857. 

crossing some of the chasms, the iron spikes at its end 
being firmly driven into the ice at one side, while the 
other end rested on the opposite side of the fissure. The 
middle portion of the glacier was not difficult. Mounds of 
ice rose beside us right and left, which were sometimes 
split into high towers and gaunt-looking pyramids, while 
the space between was unbroken. Twenty minutes' walk- 
ing brought us again to a fissured portion of the glacier, 
and here our porter left the ladder on the ice behind him. 
For some time I was not aware of this, but we were soon 
fronted by a chasm to pass which we were in consequence 
compelled to make a long and dangerous circuit amid 
crests of crumbling ice. This accomplished, we hoped 
that no repetition of the process would occur, but we 
speedily came to a second fissure, where it was neces- 
sary to step from a projecting end of ice to a mass of soft 
snow which overhung the opposite side. Simond could 
reach this snow with his long-handled axe ; he beat it 
down to give it rigidity, but it was exceedingly tender, 
and as he worked at it he continued to express his fears 
that it would not bear us. I was the lightest of the 
party, and therefore tested the passage first ; being par- 
tially lifted by Simond on the end of his axe, I crossed 
the fissure, obtained some anchorage at the other side, and 
helped the others over. We afterwards ascended until 
another chasm, deeper and wider than any we had hitherto 
encountered, arrested us. We walked alongside of it in 
search of a snow bridge, which we at length found, but the 
keystone of the arch had unfortunately given way, leaving 
projecting eaves of snow at both sides, between which we 
could look into the gulf, till the gloom of its deeper por- 
tions cut the vision short. Both sides of the crevasse were 
sounded, but no sure footing was obtained ; the snow was 
beaten and carefully trodden down as near to the edge as 
possible, but it finally broke away from the foot and fell 



18,57.] DIFFICULT CKEVASSES. 71 

into the chasm. One of our porters was short-legged and 
a bad iceman ; the other was a daring fellow, and he now 
threw the knapsack from his shoulders, came to the edge 
of the crevasse, looked into it, but drew back again. After 
a pause he repeated the act, testing the snow with his feet 
and staff. I looked at the man as he stood beside the 
chasm manifestly undecided as to whether he should take 
the step upon which his life would hang, and thought it 
advisable to put a stop to such perilous play. I accord- 
ingly interposed, the man withdrew from the crevasse, and 
he and Simond descended to fetch the ladder. 

While they were away Huxley sat down upon the ice, 
with an expression of fatigue stamped upon his counte- 
nance : the spirit and the muscles were evidently at war, 
and the resolute will mixed itself strangely with the sense 
of peril and feeling of exhaustion. He had been only two 
days with us, and, though his strength is great, he had had 
no opportunity of hardening himself by previous exercise 
upon the ice for the task which he had undertaken. The 
ladder now arrived, and we crossed the crevasse. I was 
intentionally the last of the party, Huxley being immedi- 
ately in front of me. The determination of the man dis- 
guised his real condition from everybody but myself, but 
I saw that the exhausting journey over the boulders and 
debris had been too much for his London limbs. Con- 
verting my waterproof havresack into a cushion, I made 
him sit down upon it at intervals, and by thus breaking the 
steep ascent into short stages we reached the cabin of the 
Grands Mulets together. Here I spread a rug on the 
boards, and placing my bag for a pillow, he lay down, and 
after an hour's profound sleep he rose refreshed and well ; 
but still he thought it wise not to attempt the ascent 
farther. Our porters left us : a baton was stretched across 
the room over the stove, and our wet socks and leggings 
were thrown across it to dry; our boots were placed 



7*2 STAR TWINKLING. [1857. 

around the fire, and we set about preparing our evening 
meal. A pan was placed upon the fire, and filled with 
snow, which in due time melted and boiled ; I ground some 
chocolate and placed it in the pan, and afterwards ladled 
the beverage into the vessels we possessed, which con- 
sisted of two earthen dishes and the metal cases of our 
brandy flasks. After supper Simond went out to inspect 
the glacier, and was observed bj Huxley, as twilight 
fell, in a state of deep contemplation beside a crevasse. 

Gradually the stars appeared, but as yet no moon. Be- 
fore lying down we went out to look at the firmament, and 
noticed, what I suppose has been observed to some extent 
by everybody, that the stars near the horizon twinkled 
busily, while those near the zenith shone with a steady 
light. One large star in particular excited our admira- 
tion ; it flashed intensely, and changed colour incessantly, 
sometimes blushing like a ruby, and again gleaming like 
an emerald. A determinate colour would sometimes re- 
main constant for a sensible time, but usually the flashes 
followed each other in very quick succession. Three planks 
were now placed across the room near the stove, and 
upon these, with their rugs folded round them, Huxley 
and Hirst stretched themselves, while I nestled on the 
boards at the most distant end of the room. We rose at 
eleven o'clock, renewed the fire and warmed ourselves, 
after which we lay down again. I at length observed a 
patch of pale light upon the wooden wall of the cabin, 
which had entered through a hole in the end of the edifice, 
and rising found that it was past one o'clock. The cloud- 
less moon .was shining over the wastes of snow, and the 
scene outside was at once wild, grand, and beautiful. 

Breakfast was soon prepared, though not without diffi- 
culty ; we had no candles, they had been forgotten ; but I 
fortunately possessed a box of wax matches, of which Huxley 
took charge, patiently igniting them in succession, and 



1857.] START FROM THE GRANDS MULETS. 73 

thus giving us a tolerably continuous light. We had some 
tea, which had been made at the Montanvert, and carried 
to the Grands Mulets in a bottle. My memory of that 
tea is not pleasant ; it had been left a whole night in con- 
tact with its leaves, and smacked strongly of tannin. The 
snow-water, moreover, with which we diluted it was not 
pure, but left a black residuum at the bottom of the dishes 
in which the beverage was served. The few provisions 
deemed necessary being placed in Simond's knapsack, at 
twenty minutes past two o'clock we scrambled down the 
rocks, leaving Huxley behind us. 

The snow was hardened by the night's frost, and we 
were cheered by the hope of being able to accomplish 
the ascent with comparatively little labour. We were 
environed by an atmosphere of perfect purity ; the larger 
stars hung like gems above us, and the moon, about half 
full, shone with wondrous radiance in the dark firmament. 
One star in particular, which lay eastward from the moon, 
suddenly made its appearance above one of the Aiguilles, 
and burned there with unspeakable splendour. We turned 
once towards the Mulets, and saw Huxley's form projected 
against the sky as he stood upon a pinnacle of rock ; he 
gave us a last wave of the hand and descended, while we 
receded from him into the solitudes. 

The evening previous our guide had examined the glacier 
for some distance, his progress having been arrested by a 
crevasse. Beside this we soon halted : it was spanned at 
one place by a bridge of snow, which was of too light a 
structure to permit of Simond's testing it alone ; we there- 
fore paused while our guide uncoiled a rope and tied us 
all together. The moment was to me a peculiarly solemn 
one. Our little party seemed so lonely and so small amid 
the silence and the vastness of the surrounding scene. We 
were about to try our strength under unknown conditions, 
and as the various possibilities of the enterprise crowded on 



74 A WKONG- TUEN. [1857. 

the imagination, a sense of responsibility for a moment 
oppressed me. But as I looked aloft and saw the glory of 
the heavens, my heart lightened, and I remarked cheerily 
to Hirst that Nature seemed to smile upon our work. 
" Yes," he replied, in a calm and earnest voice, " and, God 
willing, we shall accomplish it." 

A pale light now overspread the eastern sky, which 
increased, as we ascended, to a daffodil tinge ; this after- 
wards heightened to orange, deepening at one extremity 
into red, and fading at the other into a pure ethereal hue 
to which it would be difficult to assign a special name. 
Higher up the sky was violet, and this changed by insen- 
sible degrees into the darkling blue of the zenith, which 
had to thank the light of moon and stars alone for its exist- 
ence. We wound steadily for a time through valleys of 
ice, climbed white and slippery slopes, crossed a num- 
ber of crevasses, and after some time found ourselves 
beside a chasm of great depth and width, which extended 
right and left as far as we could see. We turned to the 
left, and marched along its edge in search of a pout ; but 
matters became gradually worse : other crevasses joined 
on to the first one, and the further we proceeded the more 
riven and dislocated the ice became. At length we 
reached a place where further advance was impossible. 
Simond in his difficulty complained of the want of 
light, and wished us to wait for the advancing day ; I, 
on the contrary, thought that we had light enough and 
ought to make use of it. Here the thought occurred to me 
that Simond, having been only once before to the top of the 
mountain, might not be quite clear about the route ; the 
glacier, however, changes within certain limits from year 
to year, so that a general knowledge was all that could be 
expected, and we trusted to our own muscles to make good 
any mistake in the way of guidance. We now turned and 
retraced our steps along the edges of chasms where the ice 



1857.] SEKACS OF THE D6ME DU GOITER 75 

was disintegrated and insecure, and succeeded at length in 
finding a bridge which bore us across the crevasse. This 
error caused us the loss of an hour, and after walking for this 
time we could cast a stone from the point we had attained 
to the place whence we had been compelled to return. 

Our way now lay along the face of a steep incline of 
snow, which was cut by the fissure we had just passed, in a 
direction parallel to our route. On the heights to our 
right, loose ice-crags seemed to totter, and we passed two 
tracks over which the frozen blocks had rushed some short 
time previously. We were glad to get out of the range of 
these terrible projectiles, and still more so to escape the 
vicinity of that ugly crevasse. To be killed in the open air 
would be a luxury, compared with having the life squeezed 
out of one in the horrible gloom of these chasms. The blush 
of the coming day became more and more intense ; still the 
sun himself did not appear, being hidden from us by the 
peaks of the Aiguille du Midi, which were drawn clear 
and sharp against the brightening sky. Right under this 
Aiguille were heaps of snow smoothly rounded and consti- 
tuting a portion of the sources whence the Glacier du 
Geant is fed ; these, as the day advanced, bloomed with a 
rosy light. We reached the Petit Plateau, which we found 
covered with the remains of ice avalanches ; above us upon 
the crest of the mountain rose three mighty bastions, 
divided from each other by deep vertical rents, with clean 
smooth walls, across which the lines of annual bedding 
were drawn like courses of masonry. From these, which 
incessantly renew themselves, and from the loose and 
broken ice-crags near them, the boulders amid which we 
now threaded our way had been discharged. When they 
fall their descent must be sublime. 

The snow had been gradually getting deeper, and the 
ascent more wearisome, but superadded to this at the Petit 
Plateau was the uncertainty of the footing between the 



76 THE LOST GUIDES. [1857. 

blocks of ice. In many places the space was merely 
covered by a thin crust, which, when trod upon, instantly 
yielded, and we sank with a shock sometimes to the hips. 
Our way next lay up a steep incline to the Grand Plateau, 
the depth and tenderness of the snow augmenting as we 
ascended. We had not yet seen the sun, but, as we 
attained the brow which forms the entrance to the Grand 
Plateau, he hung his disk upon a spike of rock to our 
left, and, surrounded by a glory of interference spectra 
of the most gorgeous colours, blazed down upon us. On 
the Grand Plateau we halted and had our frugal refresh- 
ment. At some distance to our left was the crevasse into 
which Dr. Hamel's three guides were precipitated by an 
avalanche in 1820 ; they are still entombed in the ice, 
and some future explorer may perhaps see them disgorged 
lower down, fresh and undecayed. They can hardly reach 
the surface until they pass the snow-line of the glacier, for 
above this line the quantity of snow that annually falls 
being in excess of the quantity melted, the tendency would 
be to make the ice-covering above them thicker. But it 
is also possible that the waste of the ice underneath may 
have brought the bodies to the bed of the glacier, where 
their very bones may have been ground to mud by an 
agency which the hardest rocks cannot withstand. 

As the sun poured his light upon the Plateau the little 
snow-facets sparkled brilliantly, sometimes with a pure 
white light, and at others with prismatic colours. Con- 
trasted with the white spaces above and around us were 
the dark mountains on the opposite side of the valley of 
Chamouni, around which fantastic masses of cloud were 
beginning to build themselves. Mont Buet, with its cone 
of snow, looked small, and the Brevent altogether mean ; 
the limestone bastions of the Fys, however, still pre- 
sented a front of gloom and grandeur. We traversed 
the Grand Plateau, and at length reached the base of an 



1857.] THE GUIDE TIRED. 77 

extremely steep incline which stretched upwards towards 
the Corridor. Here, as if produced by a fault, consequent 
upon the sinking of the ice in front, rose a vertical preci- 
pice, from the coping of which vast stalactites of ice de- 
pended. Previous to reaching this place I had noticed a 
haggard expression upon the countenance of our guide, 
which was now intensified by the prospect of the ascent 
before him. Hitherto he had always been in front, which 
was certainly the most fatiguing position. I felt that I 
must now take the lead, so I spoke cheerily to the man 
and placed him behind me. Marking a number of points 
upon the slope as resting places, I went swiftly from one 
to the other. The surface of the snow had been partially 
melted by the sun and then refrozen, thus forming a super- 
ficial crust, which bore the weight up to a certain point, 
and then suddenly gave way, permitting the leg to sink 
to above the knee. The shock consequent on this, and the 
subsequent effort necessary to extricate the leg, were ex- 
tremely fatiguing. My motion was complained of as too 
quick, and my tracks as imperfect; I moderated the 
former, and, to render my footholes broad and sure, I 
stamped upon the frozen crust, and twisted my legs in the 
soft mass underneath, a terribly exhausting process. I 
thus led the way to the base of the Rochers Rouges, up to 
which the fault already referred to had prolonged itself as 
a crevasse, which was roofed at one place by a most dan- 
gerous-looking snow-bridge. Simond came to the front ; 
I drew his attention to the state of the snow, and proposed 
climbing the Rochers Rouges ; but, with a promptness un- 
usual with him, he replied that this was impossible ; the 
bridge was our only means of passing, and we must try it. 
We grasped our ropes, and dug our feet firmly into the snow 
to check the man's descent if the pont gave way, but to our 
astonishment it bore him, and bore us safely after him. 
The slope which we had now to ascend had the snow swept 



78 A PERILOUS SLOPE. [1857. 

from its surface, and was therefore firm ice. It was most 
dangerously steep, and, its termination being the fretted 
coping of the precipice to which I have referred, if we 
slid downwards we should shoot over this and be dashed 
to pieces upon the ice below.* Simond, who had come to 
the front to cross the crevasse, was now engaged in cutting 
steps, which he made deep and large, so that they might 
serve us on our return. But the listless strokes of his 
axe proclaimed his exhaustion ; so I took the implement 
out of his hands, and changed places with him. Step after 
step was hewn, but the top of the Corridor appeared ever 
to recede from us. Hirst was behind unoccupied, and could 
thus turn his thoughts to the peril of our position : he felt 
the angle on which we hung, and saw the edge of the pre- 
cipice, to which less than a quarter of a minute's slide 
would carry us, and for the first time during the journey he 
grew giddy. A cigar which he lighted for the purpose 
tranquilized him. 

I hewed sixty steps upon this slope, and each step had 
cost a minute, by Hirst's watch. The Mur de la Cote 
was still before us, and on this the guide-books in- 
formed us two or three hundred steps were sometimes found 
necessary. If sixty steps cost an hour, what would be the 
cost of two hundred ? The question was disheartening in 
the extreme, for the time at which we had calculated on 
reaching the summit was already passed, while the chief 
difficulties remained unconquered. Having hewn our way 
along the harder ice we reached snow. I again resorted to 
stamping to secure a footing, and while thus engaged be- 
came, for the first time, aware of the drain of force to 
which I was subjecting myself. The thought of being 

* Those acquainted with the mountain will at once recognise the grave 
error here committed. In fact, on starting from the Grands Mulcts we 
had crossed the glacier too far, and throughout were much too close to the 
Dome du Gouter. 



1857.] WILL AND MUSCLE. 79 

absolutely exhausted had never occurred to me, and from 
first to last I had taken no care to husband my strength. I 
always calculated that the will would serve me even should 
the muscles fail, but I now found that mechanical laws rule 
man in the long run ; that no effort of will, no power of 
spirit, can draw beyond a certain limit upon muscular force. 
The soul, it is true, can stir the body to action, but its 
function is to excite and apply force, and not to create it. 

While stamping forward through the frozen crust I was 
compelled to pause at short intervals ; then would set out 
again apparently fresh, to find, however, in a few minutes 
that my strength was gone, and that I required to rest 
once more. In this way I gained the summit of the Cor- 
ridor, when Hirst came to the front, and I felt some relief 
in stepping slowly after him, making use of the holes into 
which his feet had sunk. He thus led the way to the base 
of the Mur de la Cote, the thought of which had so long 
cast a gloom upon us ; here we left our rope behind us, 
and while pausing I asked Simond whether he did not feel 
a desire to go to the summit " Bien sur" was his reply, 
" mais ! " Our guide's mind was so constituted that the 
u mais" seemed essential to its peace. I stretched my 
hand towards him, and said, " Simond, we must do it." 
One thing alone I felt could defeat us : the usual time of 
the ascent had been more than doubled, the day was 
already far spent, and if the ascent would throw our sub- 
sequent descent into night it could not be contemplated. 

We now faced the Mur, which was by no means so bad 
as we had expected. Driving the iron claws of our boots 
into the scars made by the axe, and the spikes of our 
batons into the slope above our feet, we ascended steadily 
until the summit was attained, and the top of the moun- 
tain rose clearly above us. We congratulated ourselves 
upon this; but Simond, probably fearing that our joy 
might become too full, remarked, " Mais le sommet est 



80 A DOZE ON THE CALOTTE. [1857. 

encore Hen loin ! " It was, alas ! too true. The snow be- 
came soft again, and our weary limbs sank in it as 
before. Our guide went on in front, audibly muttering 
his doubts as to our ability to reach the top, and at length 
he threw himself upon the snow, and exclaimed, " II faiit 
y renoncer ! " Hirst now undertook the task of rekindling 
the guide's enthusiasm, after which Simoiid rose, ex- 
claiming, "Ah! comme qa me fait mat aux genoux" and 
went forward. Two rocks break through the snow between 
the summit of the Mur and the top of the mountain ; 
the first is called the Petits Mulets, and the highest the 
Derniers Rochers. At the former of these we paused to 
rest, and finished our scanty store of wine and provisions. 
We had not a bit of bread nor a drop of wine left ; our 
brandy flasks were also nearly exhausted, and thus we had 
to contemplate the journey to the summit, and the subse- 
quent descent to the Grands Mulets, without the slightest 
prospect of physical refreshment. The almost total loss 
of two nights' sleep, with two days' toil superadded, made 
me long for a few minutes' doze, so I stretched myself 
upon a composite couch of snow and granite, and imme- 
diately fell asleep. My friend, however, soon aroused me. 
"You quite frighten me," he said; "I have listened for 
some minutes, and have not heard you breathe once." I 
had, in reality, been taking deep draughts of the moun- 
tain air, but so silently as not to be heard. 

I now filled our empty wine-bottle with snow and placed 
it in the sunshine, that we might have a little water on 
our return. We then rose ; it was half-past two o'clock ; 
we had been upwards of twelve hours climbing, and I cal- 
culated that, whether we reached the summit or not, we 
could at all events work towards it for another hour. To 
the sense of fatigue previously experienced, a new pheno- 
menon was now added the beating of the heart. We 
were incessantly pulled up by this, which sometimes be- 



1857.] THE SUMMIT ATTAINED. 81 

came so intense as to suggest danger. I counted the 
number of paces which we were able to accomplish with- 
out resting, and found that at the end of every twenty, 
sometimes at the end of fifteen, we were compelled to 
pause. At each pause my heart throbbed audibly, as I 
leaned upon my staff, and the subsidence of this action 
was always the signal for further advance. My breathing 
was quick, but light and unimpeded. I endeavoured to 
ascertain whether the hip-joint, on account of the dimi- 
nished atmospheric pressure, became loosened, so as to 
throw the weight of the leg upon the surrounding liga- 
ments, but could not be certain about it. I also sought a 
little aid and encouragement from philosophy, endeavour- 
ing to remember what great things had been done by the 
accumulation of small quantities, and I urged upon my- 
self that the present was a case in point, and that 
the summation of distances twenty paces each must finally 
place us at the top. Still the question of time left the 
matter long in doubt, and until we had passed the Derniers 
Rochers we worked on with the stern indifference of men 
who were doing their duty, and did not look to conse- 
quences. Here, however, a gleam of hope began to brighten 
our souls ; the summit became visibly nearer, Simond 
showed more alacrity ; at length success became certain, 
and at half-past three P.M. my friend and I clasped hands 
upon the top. 

The summit of the mountain is an elongated ridge, 
which has been compared to the back of an ass. It 
was perfectly manifest that we were dominant over all 
other mountains ; as far as the eye could range Mont 
Blanc had no competitor. The summits which had looked 
down upon us in the morning were now far beneath us. 
The Dome du Gouter, which had held its threatening semes 
above us so long, was now at our feet. The Aiguille du 
Midi, Mont Blanc du Tacul, and the Monts Maudits, the 

Gr 



82 CLOUDS FEOM THE SUMMIT. [1857. 

Talefre with its surrounding peaks, the Grand Jorasse, Mont 
Mallet, and the Aiguille du Geant, with our own familial- 
glaciers, were all below us. And as our eye ranged over 
the broad shoulders of the mountain, over ice hills and 
valleys, plateaux and far-stretching slopes of snow, the 
conception of its magnitude grew upon us, and impressed 
us more and more. 

The clouds were very grand grander indeed than any- 
thing I had ever before seen. Some of them seemed to 
hold thunder in their breasts, they were so dense and dark ; 
others, with their faces turned sunward, shone with the 
dazzling whiteness of the mountain snow ; while others 
again built themselves into forms resembling gigantic elm 
trees, loaded with foliage. Towards the horizon the luxury 
of colour added itself to the magnificent alternations of 
light and shade. Clear spaces of amber and ethereal green 
embraced the red and purple cumuli, and seemed to form 
the cradle in which they swung. Closer at hand squally 
mists, suddenly engendered, were driven hither and thither 
by local winds ; while the clouds at a distance lay " like 
angels sleeping on the wing," with scarcely visible motion. 
Mingling with the clouds, and sometimes rising above them, 
were the highest mountain heads, and as our eyes wandered 
from peak to peak, onwards to the remote horizon, space 
itself seemed more vast from the manner in which the 
objects which it held were distributed. 

I wished to repeat the remarkable experiment of 
De Saussure upon sound, and for this purpose had requested 
Simond to bring a pistol from Chamouni ; but in the mul- 
titude of his cares he forgot it, and in lieu of it my host at 
the Montanvert had placed in two tin tubes, of the same 
size and shape, the same amount of gunpowder, securely 
closing the tubes afterwards, and furnishing each of them 
with a small lateral aperture. We now planted one of 
them upon the snow, and bringing a strip of amadou into 



1857.] INTENSITY OF SOUND. 83 

communication with the touchhole, ignited its most distant 
end : it failed ; we tried again, and were successful, the 
explosion tearing asunder the little case which contained 
the powder. The sound was certainly not so great as I 
should have expected from an equal quantity of powder at 
the sea level.* 

The snow upon the summit was indurated, but of an 
exceedingly fine grain, and the beautiful effect already 
referred to as noticed upon the Stelvio was strikingly 
manifest. The hole made by driving the baton into the 
snow was filled with a delicate blue light ; and, by manage- 
ment, its complementary pinky yellow could also be pro- 
duced. Even the iron spike at the end of the baton made 
a hole sufficiently deep to exhibit the blue colour, which 
certainly depends on the size and arrangement of the snow 
crystals. The firmament above us was without a cloud, and 
of a darkness almost equal to that which surrounded the 
moon at 2 A.M. Still, though the sun was shining, a breeze, 
whose tooth had been sharpened by its passage over the 
snow-fields, searched us through and through. The day 
was also waning, and, urged by the warnings of our ever 
prudent guide, we at length began the descent. 

Gravity was now in our favour, but gravity could not 
entirely spare our wearied limbs, and where we sank in the 
snow we found our downward progress very trying. I 
suffered from thirst, but after we had divided the liquefied 
snow at the Petits Mulets amongst us we had nothing to 
drink. I crammed the clean snow into my mouth, but the 
process of melting was slow and tantalizing to a parched 

* I fired the second case in a field in Hampshire, and, as far as my 
memory enabled me to make the comparison, found its sound considerably 
denser, if I may use the expression. In 1859 I had a pistol fired at the 
summit of Mont Blanc : its sound was sensibly feebler and shorter than in 
the valley ; it resembled somewhat the discharge of a cork from a cham- 
pagne bottle, though much louder, but it could not be at all compared to 
the sound of a common cracker. 



84 AN UNEXPECTED GLISSADE. [1857. 

throat, while the chill was painful to the teeth. We marched 
along the Corridor, and crossed cautiously the perilous slope 
on which we had cut steps in the morning, breathing more 
freely after we had cleared the ice-precipice before de- 
scribed. Along the base of this precipice we now wound, 
diverging from our morning's track, in order to get surer 
footing in the snow ; it was like flour, and while descending 
to the Grand Plateau we sometimes sank in it nearly to 
the waist. When I endeavoured to squeeze it, so as to fill 
my flask, it at first refused to cling together, behaving 
like so much salt ; the heat of the hand, however, soon 
rendered it a little moist, and capable of being pressed into 
compact masses. The sun met us here with extraordinary 
power ; the heat relaxed my muscles, but when fairly im- 
mersed in the shadow of the Dome du Gouter, the coolness 
restored my strength, which augmented as the evening 
advanced. Simond insisted on the necessity of haste, to 
save us from the perils of darkness. " On pent perir " was 
his repeated admonition, and he was quite right. We 
reached the region of ponts, more weary, but, in compensa- 
tion, more callous, than we had been in the morning, and 
moved over the , soft snow of the bridges as if we had been 
walking upon eggs. The valley of Chamouni was filled with 
brown-red clouds, which crept towards us up the mountain ; 
the air around and above us was, however, clear, and the 
chastened light told us that day was departing. Once as 
we hung upon a steep slope, where the snow was exceed- 
ingly soft, Hirst omitted to make his footing sure ; the soft 
mass gave way, and he fell, uttering a startled shout as he 
went down the declivity. I was attached to him, and, fixing 
my feet suddenly in the snow, endeavoured to check his 
fall, but I seemed a mere feather in opposition to the force 
with which he descended.* I fell, and went down after him ; 
and we carried quite an avalanche of snow along with us, 
* I believe that I could stop him now (1860). 



1857.] BLIND AMID THE CKEVASSES. 85 

in which we were almost completely hidden at the bottom 
of the slope. All further dangers, however, were soon 
past, and we went at a headlong speed to the base of the 
Grands Mulets ; the sound of our batons against the rocks 
calling Huxley forth. A position more desolate than his 
had been can hardly be imagined. For seventeen hours 
he had been there. He had expected us at two o'clock in 
the afternoon ; the hours came and passed, and till seven 
in the evening he had looked for us. " To the end of my 
life," he said, " I shall never forget the sound of those 
batons." It was his turn now to nurse me, which he did, 
repaying my previous care of him with high interest. We 
were all soon stretched, and, in spite of cold and hard 
boards, I slept at intervals ; but the night, on the whole, 
was a weary one, and we rose next morning with muscles 
more tired than when we lay down. 

Friday, 14^ August. Hirst was almost blind this morn- 
ing; and our guide's eyes were also greatly inflamed. 
We gathered our things together, and bade the Grands 
Mulets farewell. It had frozen hard during the night, 
and this, on the steeper slopes, rendered the footing very 
insecure. Simond, moreover, appeared to be a little bewil- 
dered, and I sometimes preceded him in cutting the 
steps, while Hirst moved among the crevasses like a blind 
man ; one of us keeping near him, so that he might feel for 
the actual places where our feet had rested, and place his own 
in the same position. It cost us three hours to cross from 
the Grands Mulets to the Pierre a 1'Echelle, where we dis- 
carded our leggings, had a mouthful of food, and a brief 
rest. Once upon the safe earth Simond's powers seemed to 
be restored, and he led us swiftly downwards to the little 
auberge beside the Cascade du Tard, where we had some 
excellent lemonade, equally choice cognac, fresh straw- 
berries and cream. How sweet they were, and how beau- 
tiful we thought the peasant girl who served them ! Our 



86 HAPPY EVENINGS. [1857. 

guide kept a little hotel, at which we halted, and found it 
clean and comfortable. We were, in fact, totally unfit to 
go elsewhere. My coat was torn, holes were kicked 
through my boots, and I was altogether ragged and shabby. 
A warm bath before dinner refreshed all mightily. Dense 
clouds now lowered upon Mont Blanc, and we had not 
been an hour at Chamouni when the breaking up of the 
weather was announced by a thunder-peal. We had 
accomplished our journey just in time. 



(12.) 

After our return we spent every available hour upon the 
ice, working at questions which shall be treated under 
their proper heads, each daj's work being wound up by 
an evening of perfect enjoyment. Roast mutton and fried 
potatoes were our incessant fare, for which, after a little 
longing for a change at first, we contracted a final and 
permanent love. As the year advanced, moreover, and 
the grass sprouted with augmented vigour on the slopes of 
the Montanvert, the mutton, as predicted by our host, 
became more tender and juicy. We had also some capital 
Sallenches beer, cold as the glacier water, but effervescent 
as champagne. Such were our food and drink. After din- 
ner we gathered round the pine-fire, and I can hardly think 
it possible for three men to be more happy than we then 
were. It was not the goodness of the conversation, nor any 
high intellectual element, which gave the charm to our 
gatherings ; the gladness grew naturally out of our own 
perfect health, and out of the circumstances of our posi- 
tion. Every fibre seemed a repository of latent joy, which 
the slightest stimulus sufficed to bring into conscious action. 

On the 1 7th I penetrated with Simond through thick 
gloom to the Tacul ; on the 1 8th we set stakes at the same 



1857.] A GLACIER " BLOWEE." 87 

place : on the same day, while crossing the medial moraine 
of the Taldfre, a little below the cascade, a singular noise 
attracted my attention ; it seemed at first as if a snake 
were hissing about my feet. On changing my position the 
sound suddenly ceased, but it soon recommenced. There 
was some snow upon the glacier, which I removed, and 
placed my ear close to the ice, but it was difficult 
to fix on the precise spot from which the sound issued. 
I cut away the disintegrated portion of the surface, and 
at length discovered a minute crack, from which a 
stream of air issued, which I could feel as a cold blast 
against my hand. While cutting away the surface fur- 
ther, I stopped the little " blower." A marmot screamed 
near me, and while I paused to look at the creature 
scampering up the crags, the sound commenced again, 
changing its note variously hissing like a snake, sing- 
ing like a kettle, and sometimes chirruping intermittently 
like a bird. On passing my fingers to and fro over 
the crack, I obtained a succession of audible puffs ; the 
current was sufficiently strong to blow away the corner 
of a gauze veil held over the fissure. Still the crack 
was not wide enough to permit of the entrance of my 
finger nail ; and to issue with such force from so minute a 
rent the air must have been under considerable pressure. 
The origin of the blower was in all probability the follow- 
ing : When the ice is recompacted after having descended 
a cascade, it is next to certain that chambers of air will be 
here and there enclosed, which, being powerfully squeezed 
afterwards, will issue in the manner described whenever a 
crack in the ice furnishes it with a means of escape. In 
my experiments on flowing mud, for example, the air 
entrapped in the mass while descending from the sluice 
into the trough, bursts in bubbles from the surface at 
a short distance downwards. 

I afterwards examined the Talefre cascade from summit 



88 A DIFFICULT LINE. [1857. 

to base, with reference to the structure, until at the close 
of the day thickening clouds warned me off. I went down 
the glacier at a trot, guided by the boulders capped with 
little cairns which marked the route. The track which I 
had pursued for the last five weeks amid the crevasses near 
FAngle was this day barely passable. The glacier had 
changed, my work was drawing to a close, and, as I looked 
at the objects which had now become so familiar to me, 
I felt that, though not viscous, the ice did not lack the 
quality of " adhesiveness," and I felt a little sad at the 
thought of bidding it so soon farewell. 

At some distance below the Montanvert the Mer de 
Glace is riven from side to side by transverse crevasses : 
these fissures indicate that the glacier where they occur is 
in a state of longitudinal strain which produces transverse 
fracture. I wished to ascertain the amount of stretch- 
ing which the glacier here demanded, and which the 
ice was not able to give ; and for this purpose desired to 
compare the velocity of a line set out across the fissured 
portion with that of a second line staked out across the ice 
before it had become thus fissured. A previous inspection of 
the glacier through the telescope of our theodolite induced 
us to fix on a place which, though much riven, still did not 
exclude the hope of our being able to reach the other side. 
Each of us was, as usual, armed with his own axe ; and 
carrying with us suitable stakes, my guide and myself 
entered upon this portion of the glacier on the morning 
of the 19th of August. 

I was surprised on entering to find some veins of white 
ice, which from their position and aspect appeared to be 
derived from the Glacier du Geant ; but to these I shall 
subsequently refer. Our work was extremely difficult; 
we penetrated to some distance along one line, but 
were finally forced back, and compelled to try another. 
Right and left of us were profound fissures, and once 



1857.] "NOUS NOUS THOUVERONS PERDUS ! " 89 

a cone of ice forty feet high leaned quite over our track. 
In front of us was a second leaning mass borne by a 
mere stalk, and so topheavy that one wondered why the 
slight pedestal on which it rested did not suddenly crack 
across. We worked slowly forwards, and soon found our- 
selves in the shadow of the topheavy mass above referred 
to; and from which I escaped with a wounded hand, 
caused by over-haste. Simond surmounted the next 
ridge and exclaimed, " Nous nous trouverons perdus!" I 
reached his side, and on looking round the place saw that 
there was no footing for man. The glacier here, as shown 
in the frontispiece, was cut up into thin wedges, separated 
from each other by profound chasms, and the wedges were 
so broken across as to render creeping along their edges 
quite impossible. Thus brought to a stand, I fixed a 
stake at the point where we were forced to halt, and 
retreated along edges of detestable granular ice, which fell 
in showers into the crevasses when struck by the axe. At 
one place an exceedingly deep fissure was at our left, 
which was joined, at a sharp angle, by another at our 
right, and we were compelled to cross at the place of 
intersection : to do this we had to trust ourselves to a 
projecting knob of that vile rotten ice which I had learned 
to fear since my experience of it on the Col du Geant. 
We finally escaped, and set out our line at another place, 
where the glacier, though badly cut, was not impassable. 

On the 20th we made a series of final measurements at 
the Tacul, and determined the motion of two lines which 
we had set out the previous day. On the 21st we 
quitted the Montanvert ; I had been there from the 1 5th 
of July, and the longer I remained the better I liked the 
establishment and the people connected with it. It was 
then managed by Joseph Tairraz and Jules Charlet, both 
of whom showed us every attention. In 1858 and 1859 I 
had occasion to revisit the establishment, which was then 



90 FAREWELL TO THE MONTANVERT. [1857. 

managed by Jules and his brother, and found in it the 
same good qualities. During my winter expedition of 
1859 I also found the same readiness to assist me in every 
possible way ; honest Jules expressing his willingness to 
ascend through the snow to the auberge if I thought his 
presence would in any degree contribute to my comfort. 

We crossed the glacier, and descended by the Chapeau 
to the Cascade des Bois, the inclination of which and of 
the lower portion of the glacier we then determined. The 
day was magnificent. Looking upwards, the Aiguilles de 
Charmoz and du Dru rose right and left like sentinels of 
the valley, while in front of us the ice descended the steep, 
a bewildering mass of crags and chasms. At the other 
side was the pine-clad slope of the Montanvert. Further 
on the Aiguille du Midi threw its granite pyramid between 
us and Mont Blanc ; on the Dome du Gouter the seracs of 
the mountain were to be seen, while issuing as if from a 
cleft in the mountain side the Glacier des Bossons thrust 
through the black pines its snowy tongue. Below us was 
the beautiful valley of Chamouni itself, through which 
the Arve and Arveiron rushed like enlivening spirits. We 
finally examined a grand old moraine produced by a Mer 
de Glace of other ages, when the ice quite crossed the 
valley of Chamouni and abutted against the opposite moun- 
tain-wall. 

Simond had proved himself a very valuable assistant ; 
he was intelligent and perfectly trustworthy ; and though 
the peculiar nature of my work sometimes caused me to 
attempt things against which his prudence protested, he 
lacked neither strength nor courage. On reaching Cha- 
mouni and adding up our accounts, I found that I had not 
sufficient cash to pay him ; money was waiting for me at 
the post-office in Geneva, and thither it was arranged that 
my friend Hirst should proceed next morning, while I was 
to await the arrival of the money at Chamouni. My guide 



1857.] EDOUAED SIMOND. 91 

heard of this arrangement, and divined its cause : he came 
to me, and in the most affectionate manner begged of me 
to accept from him the loan of 500 francs. Though I did 
not need the loan, the mode in which it was offered to 
me augmented the kindly feelings which I had long enter- 
tained towards Simond, and I may add that my intercourse 
with him since has served only to confirm my first estimate 
of his worthiness. 



92 DOUBTS KEGAEDING STKUCTUKE. [1858. 



EXPEDITION OF 1858. 

(13.) 

I HAD confined myself during the summer of 1857 to the 
Mer de Glace and its tributaries, desirous to make my 
knowledge accurate rather than extensive. I had made 
the acquaintance of all accessible parts of the glacier, and 
spared no pains to master both the details and the meaning 
of the laminated structure of the ice, but I found no fact 
upon which I could take my stand and say to an advocate 
of an opposing theory, " This is unassailable." In experi- 
mental science we have usually the power of changing the 
conditions at pleasure ; if Nature does not reply to a ques- 
tion we throw it into another form ; a combining of condi- 
tions is, in fact, the essence of experiment. To meet the 
requirements of the present question, I could not twist the 
same glacier into various shapes, and throw it into different 
states of strain and pressure ; but I might, by visiting 
many glaciers, fincj. all needful conditions fulfilled in detail, 
and by observing these I hoped to confer upon the subject 
the character and precision of a true experimental inquiry. 
The summer of 1858 was accordingly devoted to this 
purpose, when I had the good fortune to be accompanied 
by Professor Ramsay, the author of some extremely in- 
teresting papers upon ancient glaciers. Taking Zurich, 
Schaffhausen, and Lucerne in our way, we crossed the 
Briinig on the 22nd of July, and met my guide, Christian 
Lauener, at Meyringen. On the 23rd we visited the 
glacier of Rosenlaui, and the glacier of the Schwartz- 
wald, and reached Grindelwald in the evening of the same 
day. My expedition with Mr. Huxley had taught me 
that the Lower Grindelwald Glacier was extremely in- 



1858.] A GLOOMY PKOSPECT. 93 

str active, and I was anxious to see many parts of it once 
more ; this I did, in company with Ramsay, and we also 
spent a day upon the upper glacier, after which our path 
lay over the Strahleck to the glaciers of the Aar and of 
the Rhone. 



PASSAGE OF THE STRAHLECK. 

(14.) 

ON Monday, the 26th of July, we were called at 4 A.M., 
and found the weather very unpromising, but the two 
mornings which preceded it had also been threatening 
without any evil result. There was, it is true, something 
more than usually hostile in the aspect of the clouds 
which sailed sullenly from the west, and smeared the air 
and mountains as if with the dirty smoke of a manufac- 
turing town. We despatched our coffee, went down to the 
bottom of the Grindelwald valley, up the opposite slope, 
and were soon amid the gloom of the pines which partially 
cover it. On emerging from these, a watery gleam on 
the mottled head of the Eiger was the only evidence of 
direct sunlight in that direction. To our left was the 
Wetterhorn surrounded by wild and disorderly clouds, 
through the fissures of which the morning light glared 
strangely. For a time the Heisse Platte was seen, a dark 
brown patch amid the ghastly blue which overspread the 
surrounding slopes of snow. The clouds once rolled up, and 
revealed for a moment the summits of the Viescherhorner ; 
but they immediately settled down again, and hid the 
mountains from top to base. Soon afterwards they drew 
themselves partially aside, and a patch of blue over the 
Strahleck gave us hope and pleasure. As we ascended, the 



94 ICE CASCADE AND PROTUBERANCES. [1858. 

prospect in front of us grew better, but that behind us 
and the wind came from behind grew worse. Slowly and 
stealthily the dense neutral-tint masses crept along the 
sides of the mountains, and seemed to dog us like spies ; 
while over the glacier hung a thin veil of fog, through which 
gleamed the white minarets of the ice. 

When we first spoke of crossing the Strahleck, Lauener 
said it would be necessary to take two guides at least ; but 
after a day's performance on the ice he thought we might 
manage very well by taking, in addition to himself, the 
herd of the alp, over the more difficult part of the pass. 
He had further experience of us on the second day, 
and now, as we approached the herd's hut, I was amused 
to hear him say that he thought any assistance beside his 
own unnecessary. Kelying upon ourselves, therefore, we 
continued our route, and were soon upon the glacier, which 
had been rendered smooth and slippery through the re- 
moval of its disintegrated surface by the warm air. Cross- 
ing the Strahleck branch of the glacier to its left side, we 
climbed the rocks to the grass and flowers which clothe the 
slopes above them. Our way sometimes layover these, some- 
times along the beds of streams, across turbulent brooks, 
and once around the face of a cliff, which afforded us 
about an inch of ledge to stand upon, and some protrud- 
ing splinters to lay hold of by the hands. Having reached 
a promontory which commanded a fine view of the glacier, 
and of the ice cascade by which it was fed, I halted, to 
check the observations already made from the side of the 
opposite mountain. Here, as there, cliffy ridges were seen 
crossing the cascade of the glacier, with interposed spaces 
of dirt and debris the former being toned down, and the 
latter squeezed towards the base of the fall, until finally 
the ridges swept across the glacier, in gentle swellings, from 
side to side ; while the valleys between them, holding the 
principal share of the superficial impurity, formed the 



1858.] DIET-BANDS OF THE STEAHLECK BEANCH. 95 

cradles of the so-called Dirt-Bands. These swept con- 
centric with the protuberances across the glacier, and 
remained upon its surface even after the swellings had 
disappeared. The swifter flow of the centre of the glacier 
tends of course incessantly to lengthen the loops of the 
bands, and to thrust the summits of the curves which they 
form more and more in advance of their lateral portions. 
The depressions between the protuberances appeared to 
be furrowed by minor wrinkles, as if the ice of the depres- 
sions had yielded more than that of the protuberances. 
This, I think, is extremely probable, though it has never 
yet been proved. Three stakes, placed, one on the summit, 
another on the frontal slope, and another at the base of a 
protuberance, would, I think, move with unequal velocities. 
They would, I think, show that, upon the large and gene- 
ral motion of the glacier, smaller motions are superposed, 
as minor oscillations are known to cover parasitically the 
large ones of a vibrating string. Possibly, also, the dirt- 
bands may owe something to the squeezing of impuri- 
ties out of the glacier to its surface in the intervals 
between the swellings. From our present position we 
could also see the swellings on the Viescherhorner branch 
of the glacier, in the valleys between which coarse shingle 
and debris were collected, which would form dirt-bands if 
they could. On neither branch, however, do the bands 
attain the definition and beauty which they possess upon 
the Mer de Glace. 

After an instructive lesson we faced our task once more, 
passing amid crags and boulders, and over steep moraines, 
from which the stones rolled down upon the slightest dis- 
turbance. While crossing a slope of snow with an inclina- 
tion of 45, my footing gave way, I fell, but turned promptly 
on my face, dug my staff deeply into the snow, and arrested 
the motion before I had slid a dozen yards. Eamsay 
was behind me, speculating whether he should be able to 



96 ICE CLIFFS THROUGH THE FOG. [1858. 

pass the same point without slipping ; before he reached 
it, however, the snow yielded, he fell, and slid swiftly 
downwards. Lauener, whose attention had been aroused 
by my fall, chanced to be looking round when Kamsay's 
footing yielded. With the velocity of a projectile he threw 
himself upon my companion, seized him, and brought him 
to rest before he had reached the bottom of the slope. The 
act made a very favourable impression upon me, it was so 
prompt and instinctive. An eagle could not swoop upon its 
prey with more directness of aim and swiftness of execution. 

While this went on the clouds were playing hide and 
seek with the mountains. The ice-crags and pinnacles to our 
left, looming through the haze, seemed of gigantic propor- 
tions, reminding one of the Hades of Byron's ' Cain.' 
" How sunless and how vast are these dim realms ! " 

We climbed for some time along the moraine which 
flanks the cascade, and on reaching the level of the brow 
Lauener paused, cast off his knapsack, and declared for 
breakfast. While engaged with it the dense clouds which 
had crammed the gorge and obscured the mountains, all 
melted away, and a scene of indescribable magnificence 
was revealed. Overhead the sky suddenly deepened to 
dark blue, and against it the Finsteraarhorn projected his 
dark and mighty mass. Brown spurs jutted from the 
mountain, and between them were precipitous snow-slopes, 
fluted by the descent of rocks and avalanches, and broken 
into ice-precipices lower down. Right in front of us, and 
from its proximity more gigantic to the eye. was the 
Schreckhorn, while from couloirs and mountain-slopes 
the matter of glaciers yet to be was poured into the 
vast basin on the rim of which we now stood. 

This it was next our object to cross; our way lying 
in part through deep snow-slush, the scene changing 
perpetually from blue heaven to gray haze which massed 
itself at intervals in dense clouds about the nioun- 



1858.] MUTATIONS OF THE CLOUDS. 97 

tains. After crossing the basin our way lay partly over 
slopes of snow, partly over loose shingle, and at one place 
along the edge of a formidable precipice of rock. We sat 
down sometimes to rest, and during these pauses, though 
they were very brief, the scene had time to go through 
several of its Protean mutations. At one moment all would 
be perfectly serene, no cloud in the transparent air to tell 
us that any portion of it was in motion, while the blue 
heaven threw its flattened arch over the magnificent am- 
phitheatre. Then in an instant, from some local cauldron, 
the vapour would boil up suddenly, eddying wildly in the 
air, which a moment before seemed so still, and envelop- 
ing the entire scene. Thus the space enclosed by the 
Finsteraarhorn, the Viescherhorner, and the Shreckhorn, 
would at one moment be filled with fog to the mountain 
heads, every trace of which a few minutes sufficed to sweep 
away, leaving the unstained blue of heaven behind it, 
and the mountains showing sharp and jagged outlines 
in the glassy air. One might be almost led to imagine 
that the vapour molecules endured a strain similar to 
that of water cooled below its freezing point, or heated 
beyond its boiling point ; and that, on the strain being re- 
lieved by the sudden yielding of the opposing force, the 
particles rushed together, and thus filled in an instant the 
clear atmosphere with aqueous precipitation. 

I had no idea that the Strahleck was so fine a pass. 
Whether it is the quality of my mind to take in the glory 
of the present so intensely as to make me forgetful of the 
glory of the past, I know not, but it appeared to me that I 
had never seen anything finer than the scene from the 
summit. The amphitheatre formed by the mountains 
seemed to me of exceeding magnificence ; nor do I think 
that my feeling was subjective merely; for the simple 
magnitude of the masses which built up the spectacle 
would be sufficient to declare its grandeur. Looking down 

H 



98 DESCENT OF THE CRAGS. [1858. 

towards the Glacier of the Aar, a scene of wild beauty 
and desolation presented itself. Not a trace of vegetation 
could be seen along the whole range of the bounding 
mountains ; glaciers streamed from their shoulders into 
the valley beneath, where they welded themselves to form 
the Finsteraar affluent of the Unteraar glacier. 

After a brief pause, Lauener again strapped on his knap- 
sack, and tempered both will and muscles by the remark, 
that our worst piece of work was now before us. From the 
place where we sat, the mountain fell precipitously for seve- 
ral hundred feet ; and down the weathered crags, and over 
the loose shingle which encumbered their ledges, our route 
now lay. Lauener was in front, cool and collected, lending 
at times a hand to Kamsay, and a word of encouragement 
to both of us, while I brought up the rear. I found my 
full haversack so inconvenient tha,t I once or twice thought 
of sending it down the crags in advance of me, but 
Lauener assured me that it would be utterly destroyed 
before reaching the bottom. My complaint against it was, 
that at critical places it sometimes came between me and 
the face of the cliff, pushing me away from the latter so 
as to throw my centre of gravity almost beyond the base 
intended to support it. We came at length upon a snow- 
slope, which had for a time an inclination of 50 ; then 
once more to the rocks ; again to the snow, which was both 
steep and deep. Our batons were at least six feet long : 
we drove them into the snow to secure an anchorage, 
but they sank to their very ends, and we merely retained 
a length of them sufficient for a grasp. This slope was 
intersected by a so-called Bergschrund, the lower portion 
of the slope being torn away from its upper portion so as 
to form a crevasse that extended quite round the head of 
the valley. We reached its upper edge ; the chasm was 
partially filled with snow, which brought its edges so near 
that we cleared it by a jump. The rest of the slope was 



1858.] THROUGH GLOOM TO THE GRIMSEL. 99 

descended by a glissade. Each sat down upon the snow, 
and the motion, once commenced, swiftly augmented to 
the rate of an avalanche, and brought us pleasantly to 
the bottom. 

As we looked from the heights, we could see that the 
valley through which our route lay was filled with gray fog : 
into this we soon plunged, and through it we made our way 
towards the Abschwung. The inclination of the glacier 
was our only guide, for we could see nothing. Eeaching 
the confluence of the Finsteraar and Lauteraar branches, 
we went downwards with long swinging strides, close 
alongside the medial moraine of the trunk glacier. The 
glory of the morning had its check in the dull gloom of 
the evening. Across streams, amid dirt-cones and glacier- 
tables, and over the long reach of shingle which covers 
the end of the glacier, we plodded doggedly, and reached 
the Grimsel at 7 P.M., the journey having cost a little more 
than 14 hours. 



(15.) 



100 ANCIENT GLACIER ACTION. [1858. 

has worked its channel into the ancient rocks. In some 
cases the road from Guttanen to the Grimsel lay right 
over the polished rocks, asperities being supplied by the 
chisel of man in order to prevent travellers from slipping 
on their slopes. Here and there also huge protuberant 
crags were rounded into domes almost as perfect as if 
chiselled by art. To both my companion and myself this 
walk was full of instruction and delight. 

On the 28th of July we crossed the Grimsel pass, and 
traced the scratchings to the very top of it. Kamsay 
remarked that their direction changed high up the pass, 
as if a tributary from the summit had produced them, 
while lower down they merged into the general direc- 
tion of the glacier which had filled the principal valley. 
From the summit of the May en wand we had a clear view 
of the glacier of the Rhone ; and to see the lower portion 
of this glacier to advantage no better position can be 
chosen. The dislocation of its cascade, the spreading out 
of the ice below, its system of radial crevasses, and the 
transverse sweep of its structural groovings, may all be 
seen. A few hours afterwards we were among the wild 
chasms at the brow of the ice-fall, where we worked our 
way to the centre of the ice, but were unable to attain the 
opposite side. 

Having examined the glacier both above and below the 
cascade, we went down the valley to Viesch, and ascended 
thence, on the 30th of July, to the Hotel Jungfrau on the 
slopes of the ^Eggischhorn. On the following day we 
climbed to the summit of the mountain, and from a 
sheltered nook enjoyed the glorious prospect which it 
commands. The wind was strong, and fleecy clouds flew 
over the heavens ; some of which, as they formed and 
dispersed themselves about the flanks of the Aletschhorn, 
showed extraordinary iridescences. 

The sunbeams called us early on the morning of the 1st 



1858.] THE MARJELEN SEE. 101 

of August. No cloud rested on the opposite range of the 
Valais mountains, but on looking towards the ^Eggischhorn 
we found a cap upon its crest ; we looked again the cap 
had disappeared and a serene heaven stretched overhead. 
As we breasted the alp the moon was still in the sky, 
paling more and more before the advancing day ; a single 
hawk swung in the atmosphere above us ; clear streams 
babbled from the hills, the louder sounds reposing on a 
base of music ; while groups of cows with tinkling bells 
browsed upon the green alp. Here and there the grass 
was dispossessed, and the flanks of the mountain were 
covered by the blocks which had been cast down from the 
summit. On reaching the plateau at the base of the final 
pyramid, we rounded the mountain to the right and came 
over the lonely and beautiful Marjelen See. No doubt the 
hollow which this lake fills had been scooped out in former 
ages by a branch of the Aletsch glacier ; but long ago 
the blue ice gave place to blue water. The glacier 
bounds it at one side by a vertical wall of ice sixty feet 
in height : this is incessantly undermined, a roof of crystal 
being formed over the water, till at length the projecting 
mass, becoming too heavy for its own rigidity, breaks and 
tumbles into the lake. Here, attacked by sun and air, 
its blue surface is rendered dazzlingly white, and several 
icebergs of this kind now floated in the sunlight ; the water 
was of a glassy smoothness, and in its blue depths each ice 
mass doubled itself by reflection.* 

The Aletsch is the grandest glacier in the Alps : over it 
we now stood, while the bounding mountains poured vast 
feeders into the noble stream. The Jungfrau was in 
front of us without a cloud, and apparently so near that I 
proposed to my guide to try it without further preparation. 
He was enthusiastic at first, but caution afterwards got the 

* A painting of this exquisite lake has been recently executed by Mr. 
George Barnard, 



102 THE ALETSCH GLACIER. [1858. 

better of his courage. At some distance up the glacier the 
snow-line was distinctly drawn, and from its edge upwards 
the mighty shoulders of the hills were heavy laden with 
the still powdery material of the glacier. 

Amid blocks and debris we descended to the ice : the 
portion of it which bounded the lake had been sapped, 
and a space of a foot existed between ice and water : 
numerous chasms were formed here, the mass being thus 
broken, preparatory to being sent adrift upon the lake. 
We crossed the glacier to its centre, and looking down it 
the grand peaks of the Mischabel, the noble cone of the 
Weisshorn, and the dark and stern obelisk of the Matter- 
horn, formed a splendid picture. Looking upwards, a 
series of most singularly contorted dirt-bands revealed 
themselves upon the surface of the ice. I sought to trace 
them to their origin, but was frustrated by the snow which 
overspread the upper portion of the glacier. Along this 
we marched for three hours, and came at length to the 
junction of the four tributary valleys which pour their 
frozen streams into the great trunk valley. The glory 
of the day, and that joy of heart which perfect health 
confers, may have contributed to produce the impression, 
but I thought I had never seen anything to rival in 
magnificence the region in the heart of which we now 
found ourselves. We climbed the mountain on the right- 
hand side of the glacier, where, seated amid the riven and 
weather-worn crags, we fed our souls for hours on the 
transcendent beauty of the scene. 

We afterwards redescended to the glacier, which at this 
place was intersected by large transverse crevasses, many 
of which were apparently filled with snow, while over 
others a thin and treacherous roof was thrown. In some 
cases the roof had broken away, and revealed rows of 
icicles of great length and transparency pendent from the 
edges. We at length turned our faces homewards, and 



1858.] A CHAMOIS DECEIVED. 103 

looking down the glacier I saw at a great distance something 
moving on the ice. I first thought it was a man, though 
it seemed strange that a man should be there alone. On 
drawing my guide's attention to it he at once pronounced 
it to be a chamois, and I with my telescope immediately 
verified his statement. The creature bounded up the gla- 
cier at intervals, and sometimes the vigour of its spring 
showed that it had projected itself over a crevasse. It 
approached us sometimes at full gallop : then would stop, 
look toward us, pipe loudly, and commence its race once 
more. It evidently made the reciprocal mistake to my 
own, imagining us to be of its own kith and kin. We 
sat down upon the ice the better to conceal our forms, 
and to its whistle our guide whistled in reply. A joyous 
rush was the creature's first response to the signal ; but 
it afterwards began to doubt, and its pauses became more 
frequent. Its form at times was extremely graceful, the 
head erect in the air, its apparent uprightness being 
augmented by the curvature which threw its horns back. 
I watched the animal through my glass until I could see 
the glistening of its eyes ; but soon afterwards it made a 
final pause, assured itself of its error, and flew with the 
speed of the wind to its refuge in the mountains. 



104 MY GUIDE, [1858. 



ASCENT OF THE FINSTERAARHORN, 1858. 

(16.) 

SINCE my arrival at the hotel on the 30th of July I had 
once or twice spoken about ascending the Finsteraarhorn, 
and on the 2nd of August my host advised me to avail 
myself of the promising weather. A guide, named Bennen, 
was attached to the hotel, a remarkable-looking man, be- 
tween 30 and 40 years old, of middle stature, but very 
strongly built. His countenance was frank and firm, while 
a light of good-nature at times twinkled in his eye. Alto- 
gether the man gave me the impression of physical strength, 
combined with decision of character. The proprietor had 
spoken to me many times of the strength and courage of 
this man, winding up his praises of him by the assurance 
that if I -were killed in Bennen's company there would 
be two lives lost, for that the guide would assuredly sacri- 
fice himself in the effort to save his Herr. 

He was called, and I asked him whether he would accom- 
pany me alone to the top of the Finsteraarhorn. To this he 
at first objected, urging the possibility of his having to 
render me assistance, and the great amount of labour 
which this might entail upon him ; but this was overruled 
by my engaging to follow where he led, without asking him 
to render me any help whatever. He then agreed to make 
the trial, stipulating, however, that he should not have 
much to carry to the cave of the Faulberg, where we were 
to spend the night. To this I cordially agreed, and sent 
on blankets, provisions, wood, and hay, by two porters. 

My desire, in part, was to make a series of observations 
at the summit of the mountain, while a similar series was 
made by Professor Ramsay in the valley of the Rhone, near 



1858.] IRIDESCENT CLOUD. 105 

Viesch, with a view to ascertaining the permeability of the 
lower strata of the atmosphere to the radiant heat of the 
sun. During the forenoon of the 2nd I occupied myself 
with my instruments, and made the proper arrangements 
with Ramsay. I tested a mountain-thermometer which 
Mr. Casella had kindly lent me, and found the boiling 
point of water on the dining-room table of the hotel to be 
199-29 Fahrenheit. At about three o'clock in the after- 
noon we quitted the hotel, and proceeded leisurely with 
our two guides up the slope of the ^ggischhorn. We 
once caught a sight of the topmost pinnacle of the Fin- 
steraarhorn ; beside it was the Rothhorn, and near this 
again the Oberaarhorn, with the Yiescher glacier streaming 
from its shoulders. On the opposite side we could see, 
over an oblique buttress of the mountain on which we 
stood, the snowy summit of the Weisshorn ; to the left of 
this was the ever grim and lonely Matterhorn ; and farther 
to the left, with its numerous snow-cones, each with 
its attendant shadow, rose the mighty Mischabel. We 
descended, and crossed the stream which flows from the 
Marjelen See, into which a large mass of the glacier had 
recently fallen, and was now afloat as an iceberg. We passed 
along the margin of the lake, and at the junction of water 
and ice I bade Ramsay good-bye. At the commencement 
of our journey upon the ice, whenever we crossed a cre- 
vasse, I noticed Bennen watching me ; his vigilance, how- 
ever, soon diminished, whence I gathered that he finally 
concluded that I was able to take care of myself. Clouds 
hovered in the atmosphere throughout the whole time of 
our ascent ; one smoky-looking mass marred the glory of 
the sunset, but at some distance was another which exhi- 
bited colours almost as rich and varied as those of the 
solar spectrum. I took the glorious banner thus unfurled 
as a sign of hope, to check the despondency which its 
gloomy neighbour was calculated to produce. 



106 EVENING- NEAR THE JUNGFRAU. [1858. 

Two hours' walking brought us near our place of rest ; 
the porters had already reached it, and were now returning. 
We deviated to the right, and, having crossed some ice- 
ravines, reached the lateral moraine of the glacier, and 
picked our way between it and the adjacent mountain- wall. 
We then reached a kind of amphitheatre, crossed it, and 
climbing the opposite slope, came to a triple grotto formed 
by clefts in the mountain. In one of these a pine-fire 
was soon blazing briskly, and casting its red light upon 
the surrounding objects, though but half dispelling the 
gloom from the deeper portions of the cell. I left the 
grotto, and climbed the rocks above it to look at the heavens. 
The sun had quitted our firmament, but still tinted the 
clouds with red and purple ; while one peak of snow ' in 
particular glowed like fire, so vivid was its illumination. 
During our journey upwards the Jungfrau never once 
showed her head, but, as if in ill temper, had wrapped her 
vapoury veil around her. She now looked more good- 
humoured, but still she did not quite remove her hood ; 
though all the other summits, without a trace of cloud to 
mask their beautiful forms, pointed heavenward. The 
calmness was perfect; no sound of living creature, no 
whisper of a breeze, no gurgle of water, no rustle of 
debris, to break the deep and solemn silence. Surely, if 
beauty be an object of worship, those glorious mountains, 
with rounded shoulders of the purest white snow-crested 
and star-gemmed were well calculated to excite senti- 
ments .of adoration. 

I returned to the grotto, where supper was prepared and 
waiting for me. The boiling point of water, at the level 
of the " kitchen " floor, I found to be 196 Fahr. Nothing 
could be more picturesque than the aspect of the cave 
before we went to rest. The fire was gleaming ruddily. I 
sat upon a stone bench beside it, while Bennen was in front 
with the red light glimmering fitfully o^er him. My 



1858.] THE CAVE OF THE FAULBERG. 107 

boiling-water apparatus, which had just been used, was in 
the foreground ; and telescopes, opera-glasses, haversacks, 
wine-keg, bottles, and mattocks, lay confusedly around. 
The heavens continued to grow clearer, the thin clouds, 
which had partially overspread the sky, melting gradually 
away. The grotto was comfortable; the hay sufficient 
materially to modify the hardness of the rock, and my posi- 
tion at least sheltered and warm. One possibility re- 
mained that might prevent me from sleeping the snoring 
of my companion ; he assured me, however, that he did 
not snore, and we lay down side by side. The good fellow 
took care that I should not be chilled ; he gave me the 
best place, by far the best part of the clothes, and may have 
suffered himself in consequence ; but, happily for him, 
he was soon oblivious of this. Physiologists, I believe, have 
discovered that it is chiefly during sleep that the muscles 
are repaired ; and ere long the sound I dreaded announced 
to me at once the repair of Bennen's muscles and the 
doom of my own. The hollow cave resounded to the deep- 
drawn snore. I once or twice stirred the sleeper, breaking 
thereby the continuity of the phenomenon; but it in- 
stantly pieced itself together again, and went on as before. 
I had not the heart to wake him, for I knew that upon 
him would devolve the chief labour of the coming day. 
At half-past one he rose and prepared coffee, and at two 
o'clock I was engaged upon the beverage. We afterwards 
packed up our provisions and instruments. Bennen bore 
the former, I the latter, and at three o'clock we set out. 

We first descended a steep slope to the glacier, along 
which we walked for a time. A spur of the Faulberg jutted 
out between us and the ice-laden valley through which we 
must pass ; this we crossed in order to shorten our way 
and to avoid crevasses. Loose shingle and boulders over- 
laid the mountain; and here and there walls of rock 
opposed our progress, and rendered the route far from 



108 "SHALL WE TEY THE JUNGFEAU ? " [1858. 

agreeable. We then descended to the Griinhorn tributary, 
which joins the trunk glacier at nearly a right angle, being 
terminated by a saddle which stretches across from moun- 
tain to mountain, with a curvature as graceful and as 
perfect as if drawn by the instrument of a mathematician. 
The unclouded moon was shining, and the Jungfrau was 
before us so pure and beautiful, that the thought of visiting 
the " Maiden " without further preparation occurred to me. 
I turned to Bennen, and said, " Shall we try the Jungfrau ? " 
I think he liked the idea well enough, though he cau- 
tiously avoided incurring any responsibility. " If you de- 
sire it, I am ready," was his reply. He had never made 
the ascent, and nobody knew anything of the state of the 
snow this year ; but Lauener had examined it through a 
telescope on the previous day, and pronounced it dan- 
gerous. In every ascent of the mountain hitherto made, 
ladders had been found indispensable, but we had none. 
I questioned Bennen as to what he thought of the proba- 
bilities, and tried to extract some direct encouragement 
from him ; but he said that the decision rested altogether 
with myself, and it was his business to endeavour to carry 
out that decision. " We will attempt it, then," I said, and 
for some time we actually walked towards the Jungfrau. 
A gray cloud drew itself across her summit, and clung 
there. I asked myself ' why I deviated from my ori- 
ginal intention ? The Finsteraarhorn was higher, and 
therefore better suited for the contemplated observa- 
tions. I could in no wise justify the change, and finally 
expressed my scruples. A moment's further conversation 
caused us to " right about," and front the saddle of the 
Griinhorn. 

The dawn advanced. The eastern sky became illumi- 
nated and warm, and high in the air across the ridge in 
front of us stretched a tongue of cloud like a red flame, 
and equally fervid in its hue. Looking across the trunk 



18-58.] MAGNIFICENT SCENE. 109 

glacier, a valley which is terminated by the Lotsch saddle 
was seen in a straight line with our route, and I often 
turned to look along this magnificent corridor. The 
mightiest mountains in the Oberland form its sides ; still, 
the impression which it makes is not that of vastness or 
sublimity, but of loveliness not to be described. The sun 
had not yet smitten the snows of the bounding moun- 
tains, but the saddle carved out a segment of the heavens 
which formed a background of unspeakable beauty. Over 
the rim of the saddle the sky was deep orange, pass- 
ing upwards through amber, yellow, and vague ethereal 
green to the ordinary firmamental blue. Right above 
the snow-curve purple clouds hung perfectly motionless, 
giving depth to the spaces between them. There was 
something saintly in the scene. Anything more exquisite 
I had never beheld. 

We marched upwards over the smooth crisp snow to the 
crest of the saddle, and here I turned to take a last look 
along that grand corridor, and at that wonderful " daffodil 
sky." The sun's rays had already smitten the snows of the 
Aletschhorn ; the radiance seemed to infuse a principle of 
life and activity into the mountains and glaciers, but still 
that holy light shone forth, and those motionless clouds 
floated beyond, reminding one of that eastern religion whose 
essence is the repression of all action and the substitution 
for it of immortal calm. The Finsteraarhorn now fronted 
us ; but clouds turbaned the head of the giant, and hid it 
from our view. The wind, however, being north, inspired 
us with a strong hope that they would melt as the day ad- 
vanced. I have hardly seen a finer ice-field than that 
which now lay before us. Considering the neve which 
supplies it, it appeared to me that the Viescher glacier 
ought to discharge as much ice as the Aletsch ; but 
this is an error due to the extent of neve which is here 
at once visible : since a glance at the map of this portion 



110 THE MOITNTAIK ASSAILED. [ 18-58. 

of the Oberland shows at once the great superiority of 
the mountain treasury from which the Aletsch glacier 
draws support. Still, the ice-field before us was a most 
noble one. The surrounding mountains were of imposing 
magnitude, and loaded to their summits with snow. Down 
the sides of some of them the half-consolidated mass fell in 
a state of wild fracture and confusion. In some cases the 
riven masses were twisted and overturned, the ledges bent, 
and the detached blocks piled one upon another in heaps ; 
while in other cases the smooth white mass descended 
from crown to base without a wrinkle. The valley 
now below us was gorged by the frozen material thus 
incessantly poured into it. We crossed it, and reached the 
base of the Finsteraarhorn, ascended the mountain a little 
way, and at six o'clock paused to lighten our burdens and 
to refresh ourselves. 

The north wind had freshened, we were in the shade, 
and the cold was very keen. Placing a bottle of tea 
and a small quantity of provisions in the knapsack, and 
a few figs and dried prunes in our pockets, we com- 
menced the ascent. The Finsteraarhorn sends down a 
number of cliffy buttresses, separated from each other by 
wide couloirs filled with ice and snow. We ascended 
one of these buttresses for a time, treading cautiously 
among the spiky rocks ; afterwards we went along the 
snow at the edge of the spine, and then fairly parted 
company with the rock, abandoning ourselves to the neve 
of the couloir. The latter was steep, and the snow was 
so firm that steps had to be cut in it. Once I paused 
upon a little ledge, which gave me a slight footing, and 
took the inclination. The slope formed an angle of 45 
with the horizon ; and across it, at a little distance be- 
low me, a gloomy fissure opened its jaws. The sun now 
cleared the summits which had before cut off his rays, and 
burst upon us with great power, compelling us to resort to 



1858.] THE CREST OF BOOKS. Ill 

our veils and dark spectacles. Two years before, Bennen 
had been nearly blinded by inflammation brought on by 
the glare from the snow, and he now took unusual care in 
protecting his eyes. The rocks looking more practicable, 
we again made towards them, and clambered among them 
till a vertical precipice, which proved impossible of ascent, 
fronted us. Bennen scanned the obstacle closely as we 
slowly approached it, and finally descended to the snow, 
which wound at a steep angle round its base : on this the 
footing appeared to me to be singularly insecure, but I 
marched without hesitation or anxiety in the footsteps of 
my guide. 

We ascended the rocks once more, continued along 
them for some time, and then deviated to the couloir 
on our left. This snow-slope is much dislocated at its 
lower portion, and above its precipices and crevasses our 
route now lay. The snow was smooth, and sufficiently 
firm and steep to render the cutting of steps necessary. 
Bennen took the lead : to make each step he swung his 
mattock once, and his hindmost foot rose exactly at the 
moment the mattock descended ; there was thus a kind of 
rhythm in his motion, the raising of the foot keeping 
time to the swing of the implement. In this manner we 
proceeded till we reached the base of the rocky pyramid 
which caps the mountain. 

One side of the pyramid had been sliced off, thus 
dropping down almost a sheer precipice for some thousands 
of feet to 'the Finsteraar glacier. A wall of rock, about 
10 or 15 feet high, runs along the edge of the moun- 
tain, and this sheltered us from the north wind, which 
surged with the sound of waves against the tremendous 
barrier at the other side. " Our hardest work is now 
before us," said my guide. Our way lay up the steep 
and splintered rocks, among which we sought out the 
spikes which were closely enough wedged to bear our 



112 THE SUMMIT GAINED. [1858. 

weight. Each had to trust to himself, and I fulfilled 
to the letter my engagement with Bennen to ask no 
help. My boiling- water apparatus and telescope were 
on my back, much to my annoyance, as the former was 
heavy, and sometimes swung awkwardly round as I twisted 
myself among the cliffs. Bennen offered to take it, but he 
had his own share to carry, and I was resolved to bear 
mine. Sometimes the rocks alternated with spaces of 
ice and snow, which we were at intervals compelled to 
cross ; sometimes, when the slope was pure ice and very 
steep, we were compelled to retreat to the highest cliffs. 
The wall to which I have referred had given way in 
some places, and through the gaps thus formed the 
wind rushed with a loud, wild, wailing sound. Through 
these spaces I could see the entire field of Agassiz's obser- 
vations; the junction of the Lauteraar and Finsteraar 
glaciers at the Abschwung, the medial moraine between 
them, on which stood the Hotel des Neufchatelois, and the 
pavilion built by M. Dollfuss, in which Huxley and myself 
had found shelter two years before. Bennen was evidently 
anxious to reach the summit, and recommended all obser- 
vations to be postponed until after our success had been 
assured. I agreed to this, and kept close at his heels. 
Strong as he was, he sometimes paused, laid his head upon 
his mattock, and panted like a chased deer. He com- 
plained of fearful thirst, and to quench it we had only my 
bottle of tea : this we shared loyally, my guide praising 
its virtues, as well he might. Still the summit loomed 
above us ; still the angry swell of the north wind, beating 
against the torn battlements of the mountain, made wild 
music. Upward, however, we strained ; and at last, on 
gaining the crest of a rock, Bennen exclaimed, in a jubilant 
voice, l( Die hochste Spitze ! " the highest point. In a 
moment I was at his side, and saw the summit within a 
few paces of us. A minute or two placed us upon 



1858.] THERMOMETER PLACED. 113 

the topmost pinnacle, with the blue dome of heaven 
above us, and a world of mountains, clouds, and glaciers 
beneath. 

A notion is entertained by many of the guides that if 
you go to sleep at the summit of any of the highest moun- 
tains, you will 

" Sleep the sleep that knows no waking." 

Bennen did not appear to entertain this superstition ; and 
before starting in the morning, I had stipulated for ten 
minutes' sleep on reaching the summit, as part compensa- 
tion for the loss of the night's rest. My first act, after 
casting a glance over the glorious scene beneath us, was 
to take advantage of this agreement ; so I lay down and 
had five minutes' sleep, from which I rose refreshed 
and brisk. The sun at first beat down upon us with 
intense force, and I exposed my thermometers ; but thin 
veils of vapour soon drew themselves before the sun, and 
denser mists spread over the valley of the Khone, thus 
destroying all possibility of concert between Ramsay and 
myself. I turned therefore to my boiling-water apparatus, 
filled it with snow, melted the first charge, put more in, 
and boiled it ; ascertaining the boiling point to be 187 
Fahrenheit. On a sheltered ledge, about two or three 
yards south of the highest point, I placed a minimum- 
thermometer, in the hope that it would enable us in future 
years to record the lowest winter temperatures at the 
summit of the mountain.* 

* The following note describes the single observation made with this 
thermometer. Mr. B. informs me that on finding the instrument Bennen 
swung it in triumph round his head. I fear, therefore, that the obser- 
vation gives'us no certain information regarding the minimum winter- 
temperature. 

" St. Nicholas, 1859, Aug. 25. 

" Sir, On Tuesday last (the 23rd inst.) a party, consisting of Messrs. 
B., H., R. L., and myself, succeeded in reaching the summit of the 
Finsteraarhorn under the guidance of Bennen and Melchior Anderegg. 

I 



114 SCENE FKOM THE SUMMIT. [1858. 

It is difficult to convey any just impression of the scene 
from the summit of the Fiiisteraarhorn : one might, it is 
true, arrange the visible mountains in a list, stating their 
heights and distances, and leaving the imagination to fur- 
nish them with peaks and pinnacles, to build the precipices, 
polish the snow, rend the glaciers, and cap the highest 
summits with appropriate clouds. But if imagination did 
its best in this way, it would hardly exceed the reality, 
and would certainly omit many details which contribute 
to the grandeur of the scene itself. The various shapes 
of the mountains, some grand, some beautiful, bathed 
in yellow sunshine, or lying black and riven under the 
frown of impervious cumuli ; the pure white peaks, cor- 
nices, bosses, and amphitheatres ; the blue ice rifts, the 

We made it an especial object to observe and reset the minimum - 
thermometer which you left there last year. On reaching the summit, 
before I had time to stop him, Bennen produced the instrument, and it 
is just possible that in moving it he may have altered the position 
of the index. However, as he held the instrument horizontally, and did 
not, as far as I saw, give it any sensible jerk, I have great confidence that 
the index remained unmoved. 

" The reading of the index was - 32 Cent. 

" A portion of the spirit extending over about 10| (and standing 
tween 33 and 43^) was separated from the rest, but there appeared to 
be no data for determining when the separation had taken place. As it 
appeared desirable to unite the two portions of spirit before again setting 
the index to record the cold of another winter, we endeavoured to effect 
this by heating the bulb, but unfortunately, just as we were expecting to 
see them coalesce, the bulb burst, and I have now to express my great 
regret that my clumsiness or ignorance of the proper mode of setting the 
instrument in order should have interfered with the continuance of obser- 
vations of so much interest. The remains of the instrument, together 
with a note of the accident, I have left in the charge of Wellig, the land- 
lord of the hotel on the /Eggischhorn. 

" We reached the summit about 10.40 A.M. and remained there till noon ; 
the reading of a pocket thermometer in the shade was 41 F. 

" Should there be any further details connected with our ascent on which 
you would like to have information, I shall be happy to supply them to 
the best of my recollection. Meanwhile, with a farther apology for my 
clumsiness, I beg to subscribe myself yours respectfully, 

" Professor Tyndall." " H." 



1858.] "HAVE NO FEAR." 115 

stratified snow-precipices, the glaciers issuing from the 
hollows of the eternal hills, and stretching like frozen 
serpents through the sinuous valleys ; the lower cloud 
field itself an empire of vaporous hills shining with 
dazzling whiteness, while here and there grim summits, 
brown by nature, and black by contrast, pierce through it 
like volcanic islands through a shining sea, add to this 
the consciousness of one's position which clings to one 
unconsciously, that undercurrent of emotion which sur- 
rounds the question of one's personal safety, at a height of 
more than 14,000 feet above the sea, and which is increased 
by the weird strange sound of the wind surging with the 
full deep boom of the distant sea against the precipice 
behind, or rising to higher cadences as it forces itself 
through the crannies of the weatherworn rocks, all 
conspire to render the scene from the Finsteraarhorn 
worthy of the monarch of the Bernese Alps. 

My guide at length warned me that we must be moving ; 
repeating the warning more impressively before I attended 
to it. We packed up, and as we stood beside each other 
ready to march he asked me whether we should tie our- 
selves together, at the same time expressing his belief that 
it was unnecessary. Up to this time we had been separate, 
and the thought of attaching ourselves had not occurred to 
me till he mentioned it. I thought it, however, prudent to 
accept the suggestion, and so we united our destinies by a 
strong rope. " Now," said Bennen, " have no fear ; no matter 
how you throw yourself, I will hold you." Afterwards, on 
another perilous summit, I repeated this saying of Bennen's 
to a strong and active guide, but his observation was that it 
was a hardy untruth, for that in many places Bennen could 
not have held me. Nevertheless a daring word strengthens 
the heart, and, though I felt no trace of that sentiment 
which Bennen exhorted me to banish, and was determined, 
as far as in me lay, to give him no opportunity of trying 

i 2 



116 DISCIPLINE. [18;>8. 

his strength in saving me, I liked the fearless utterance of 
the man, and sprang cheerily after him. Our descent was 
rapid, apparently reckless, amid loose spikes, boulders, 
and vertical prisms of rock, where a false step would 
assuredly have been attended with broken bones ; but the 
consciousness of certainty in our movements never forsook 
us, and proved a source of keen enjoyment. The senses 
were all awake, the eye clear, the heart strong, the limbs 
steady, yet flexible, with power of recovery in store, and 
ready for instant action should the footing give way. Such 
is the discipline which a perilous ascent imposes. 

We finally quitted the crest of rocks, and got fairly 
upon the snow once more. We first went downwards 
at a long swinging trot. The sun having melted the 
crust which we were compelled to cut through in the 
morning, the leg at each plunge sank deeply into the 
snow ; but this sinking was partly in the direction of the 
slope of the mountain, and hence assisted our progress. 
Sometimes the crust was hard enough to enable us to glide 
upon it for long distances while standing erect ; but the end 
of these glissades was always a plunge and tumble in the 
deeper snow. Once upon a steep hard slope Bennen's footing 
gave way ; he fell, and went down rapidly, pulling me after 
him. I fell also, but turning quickly, drove the spike of 
my hatchet into the ice, got good anchorage, and held 
both fast ; my success assuring me that I had improved 
as a mountaineer since my ascent of Mont Blanc. We 
tumbled so often in the soft snow, and our clothes and 
boots were so full of it, that we thought we might 
as well try the sitting posture in gliding down. We 
did so, and descended with extraordinary velocity, being 
checked at intervals by a bodily immersion in the softer 
and deeper snow. I was usually in front of Bennen, shooting 
down with the speed of an arrow and feeling the check of the 
rope when the rapidity of my motion exceeded my guide's 



1858.] DESCENT BY GLISSADES. 117 

estimate of what was safe. Sometimes I was behind him, 
and darted at intervals with the swiftness of an avalanche 
right upon him ; sometimes in the same transverse line with 
him, with the full length of the rope between us ; and here 
I found its check unpleasant, as it tended to make me roll 
over. My feet were usually in the air, and it was only 
necessary to turn them right or left, like the helm of a 
boat, to change the direction of motion and avoid a diffi- 
culty, while a vigorous dig of leg and hatchet into the 
snow was sufficient to check the motion and bring us to 
rest. Swiftly, yet cautiously, we glided into the region of 
crevasses, where we at last rose, quite wet, and resumed 
our walking, until we reached the point where we had left 
our wine in the morning, and where I squeezed the water 
from my wet clothes, and partially dried them in the sun. 
We had left some things at the cave of the Faulberg, 
and it was Bennen's first intention to return that way and 
take them home with him. Finding, however, that we 
could traverse the Viescher glacier almost to the ^Eggisch- 
horn, I made this our highway homewards. At the place 
where we entered it, and for an hour or two afterwards, 
the glacier was cut by fissures, for the most part covered 
with snow. We had packed up our rope, and Bennen ad- 
monished me to tread in his steps. Three or four times he 
half disappeared in the concealed fissures, but by clutch- 
ing the snow he rescued himself and went on as swiftly as 
before. Once my leg sank, and the ring of icicles some 
fifty feet below told me that I was in the jaws of a cre- 
vasse; my guide turned sharply it was the only time 
that I had seen concern on his countenance : 

" Gott's Donner ! 8ie haben meine Tritte nicht gefolgt." 

il Dock ! " was my only reply, and we went on. He 

scarcely tried the snow that he crossed, as from its form 

and colour he could in most cases judge of its condition. 

For a long time we kept at the left-hand side of the 



118 THE VIESCH GLACIER [1858. 

glacier, avoiding the fissures which were now permanently 
open. We came upon the tracks of a herd of chamois, 
which had clambered from the glacier up the sides of the 
Oberaarhorn, and afterwards crossed the glacier to the 
right-hand side, my guide being perfect master of the 
ground. His eyes went in advance of his steps, and his 
judgment was formed before his legs moved. The glacier 
was deeply fissured, but there was no swerving, no retreat- 
ing, no turning back to seek more practicable routes ; 
each stride told, and every stroke of the axe was a pro- 
fitable investment of labour. 

We left the glacier for a time, and proceeded along the 
mountain side, till we came near the end of the Trift 
glacier, where we let ourselves down an awkward face of 
rock along the track of a little cascade, and came upon 
the glacier once more. Here again I had occasion to 
admire the knowledge and promptness of my guide. The 
glacier, as is well known, is greatly dislocated, and has 
once or twice proved a prison to guides and travellers, 
but Bennen led me through the confusion without a pause. 
We were sometimes in the middle of the glacier, sometimes 
on the moraine, and sometimes on the side of the flanking 
mountain. Towards the end of the day we crossed what 
seemed to be the consolidated remains of a great ava- 
lanche ; on this my foot slipped, there was a crevasse at 
hand, and a sudden effort was necessary to save me from 
falling into it. In making this effort the spike of my 
axe turned uppermost, and the palm of my hand came 
down upon it, thus receiving a very ugly wound. We were 
soon upon the green alp, having bidden a last farewell 
to the ice. Another hour's hard walking brought us to our 
hotel. No one seeing us crossing the alp would have sup- 
posed that we had laid such a day's work behind us ; the 
proximity of home gave vigour to our strides, and our pro- 
gress was much more speedy than it had been on starting in 



1858.] A ROTATING ICEBEKG. 119 

the morning. I was affectionately welcomed by Ramsay, 
had a warm bath, dined, went to bed, where I lay fast 
locked in sleep for eight hours, and rose next morning as 
fresh and vigorous as if I had never scaled the Finster- 
aarhorn. 



(17.) 

On the 6th of August there was a long fight between 
mist and sunshine, each triumphing by turns, till at length 
the orb gained the victory and cleansed the mountains 
from every trace of fog. We descended to the Marjelen 
See, and, wishing to try the floating power of its icebergs, 
at a place where masses sufficiently large approached 
near to the shore, I put aside a portion of my clothes, 
and retaining my boots stepped upon the floating ice. It 
bore me for a time, and I hoped eventually to be able to 
paddle myself over the water. On swerving a little, 
however, from the position in which I first stood, the 
mass turned over and let me into the lake. I tried a 
second one, which served me in the same manner ; the 
water was too cold to continue the attempt, and there 
was also some risk of being unpleasantly ground between 
the opposing surfaces of the masses of ice. A very large 
iceberg which had been detached some short time pre- 
viously from the glacier lay -floating at some distance 
from us. Suddenly a sound like that of a waterfall drew 
our attention towards it. We saw it roll over with the 
utmost deliberation, while the water which it carried along 
with it rushed in cataracts down its sides. Its previous 
surface was white, its present one was of a lovely blue, the 
* submerged crystal having now come to the air. The 
summerset of this iceberg produced a commotion all over 
the lake ; the floating masses at its edge clashed together, 



120 END OF THE ALETSCH GLACIER. [1858. 

and a mellow glucking sound, due to the lapping of the 
undulations against the frozen masses, continued long 
afterwards. 

We subsequently spent several hours upon the glacier ; 
and on this day I noticed for the first time a contempo- 
raneous exhibition of bedding and structure to which I shall 
refer at another place. We passed finally to the left bank 
of the glacier, at some distance below the base of the 
^Eggischhorn, and traced its old moraines at intervals along 
the flanks of the bounding mountain. At the summit of 
the ridge we found several fine old rocJies moutonnees, on 
some of which the scratchings of a glacier long departed 
were well preserved ; and from the direction of the 
scratchings it might be inferred that the ice moved down 
the mountain towards the valley of the Rhone. A plunge 
into a lonely mountain lake ended the day's excursion; 

On the 7th of August we quitted this noble station. 
Sending our guide on to Viesch to take a conveyance and 
proceed with our luggage down the valley, Ramsay and 
myself crossed the mountains obliquely, desiring to trace 
the glacier to its termination. We had no path, but it was 
hardly possible to go astray. We crossed spurs, climbed and 
descended pleasant mounds, sometimes with the soft grass 
under our feet, and sometimes knee-deep in rhododendrons. 
It took us several hours to reach the end of the glacier, 
and we then looked down upon it merely. It lay 
couched like a reptile in a wild gorge, as if it had split 
the mountain by its frozen snout. We afterwards de- 
scended to Morill, where we met our guide and driver ; 
thence down the valley to Visp ; and the following evening 
saw us lodged at the Monte Rosa hotel in Zermatt. 

The boiling point of water on the table of the salle cl 
manger, I found to be 202-58 Fahr. 

On the following morning I proceeded without my friend 
to the Gomer glacier. As is well known, the end of this 



1858.] MEADOWS INVADED BY ICE. 121 

glacier has been steadily advancing for several years, and 
when I saw it, the meadow in front of it was partly 
shrivelled up by its irresistible advance. I was informed 
by my host that within the last sixty years forty-four chalets 
had been overturned by the glacier, the ground on which 
they stood being occupied by the ice ; at present there 
are others for which a similar fate seems imminent. 
In thus advancing the glacier merely takes up ground 
which belonged to it in former ages, for the rounded 
rocks which rise out of the adjacent meadow show that it 
once passed over them. 

I had arranged to meet Kamsay this morning on the 
road to the Kiffelberg. The meeting took place, but I then 
learned that a minute or two after my departure he had 
received intelligence of the death of a near relative. Thus 
was our joint expedition terminated, for he resolved to 
return at once to England. At my solicitation he accom- 
panied me to the Eiffel hotel. We had planned an ascent 
of Monte Eosa together, but the arrangement thus broke 
clown, and I was consequently thrown upon my own re- 
sources. Lauener had never made the ascent, but he 
nevertheless felt confident that we should accomplish it 
together. 



122 THE RIFFELBERO. [1858. 



FIRST ASCENT OF MONTE ROSA, 1858. 
(18.) 

ON Monday, the 9tli of August, we reached the Eiffel, 
and, by good fortune, on the evening of the same day, my 
guide's brother, the well-known Ulrich Lauener, also arrived 
at the hotel on his return from Monte Rosa. From him we 
obtained all the information possible respecting the ascent, 
and he kindly agreed to accompany us a little way the 
next morning, to put us on the right track. At three A.M. 
the door of my bedroom opened, and Christian Lauener 
announced to me that the weather was sufficiently good to 
justify an attempt. The stars were shining overhead ; but 
Ulrich afterwards drew our attention to some heavy clouds 
which clung to the mountains on the other side of the 
valley of the Visp ; remarking that the weather might 
continue fair throughout the day, but that these clouds 
were ominous. At four o'clock we were on our way, by 
which time a gray stratus cloud had drawn itself across 
the neck of the Matterhorn, and soon afterwards another 
of the same nature encircled his waist. We proceeded 
past the Riffelhorn to the ridge above the Gorner glacier, 
from which Monte Rosa was visible from top to bottom, 
and where an animated conversation in Swiss patois com- 
menced. Ulrich described the slopes, passes, and pre- 
cipices, which were to guide us ; and Christian demanded 
explanations, until he was finally able to declare to me 
that his knowledge was sufficient. We then bade Ulrich 
good-bye, and went forward. All was clear about Monte 
Rosa, and the yellow morning light shone brightly upon 
its uppermost snows. Beside the Queen of the Alps 
was the huge mass of the Lyskamm, with a saddle 
stretching from the one to the other ; next to the Lyskamm 



1858.] SOUNDS ON THE GLACIEK. 123 

came two white rounded mounds, smooth and pure, the 
Twins Castor and Pollux, and further to the right again 
the broad brown flank of the Breithorn. Behind us 
Mont Cervin gathered the clouds more thickly round him, 
until finally his grand obelisk was totally hidden. We 
went along the mountain-side for a time, and then de- 
scended to the glacier. The surface was hard frozen, and 
the ice crunched loudly under our feet. There was a hol- 
lowness and volume in the sound which require explana- 
tion ; and this, I think, is furnished by the remarks of Sir 
John Herschel on those hollow sounds at the Solfaterra, 
near Naples, from which travellers have inferred the exist- 
ence of cavities within the mountain. At the place where 
these sounds are heard the earth is friable, and, when 
struck, the concussion is reinforced and lengthened by the 
partial echoes from the surfaces of the fragments. The 
conditions for a similar effect exist upon the glacier, for 
the ice is disintegrated to a certain depth, and from the 
innumerable places of rupture little reverberations are 
sent, which give a length and hollowness to the sound pro- 
duced by the crushing of the fragments on the surface. 

We looked to the sky at intervals, and once a meteor 
slid across it, leaving a train of sparks behind. The blue 
firmament, from which the stars shone down so brightly 
when we rose, was more and more invaded by clouds, 
which advanced upon us from our rear, while before us the 
solemn heights of Monte Rosa were bathed in rich yellow 
sunlight. As the day advanced the radiance crept down 
towards the valleys ; but still those stealthy clouds ad- 
vanced like a besieging army, taking deliberate possession 
of the summits, one after the other, while gray skirmishers 
moved through the air above us. The play of light and 
shadow upon Monte Rosa was at times beautiful, bars of 
gloom and zones of glory shifting and alternating from top 
to bottom of the mountain. 



124 ADVANCE OF THE CLOUDS. [1858. 

At five o'clock a gray cloud alighted on the shoulder of 
the Lyskamm, which had hitherto been warmed by the 
lovely yellow light. Soon afterwards we reached the foot 
of Monte Rosa, and passed from the glacier to a slope of 
rocks, whose rounded forms and furrowed surfaces showed 
that the ice of former ages had moved over them ; the 
granite was now coated with lichens, and between the 
bosses where mould could rest were patches of tender 
moss. As we ascended, a peal to the right announced the 
descent of an avalanche from the Twins ; it came heralded 
by clouds of ice-dust, which resembled the sphered masses 
of condensed vapour which issue from a locomotive. A 
gentle snow-slope brought us to the base of a 'precipice 
of brown rocks, round which we wound ; the snow was 
in excellent order, and the chasms were so firmly bridged 
by the frozen mass that no caution was necessary in 
crossing them. Surmounting a weathered cliff to our left, 
we paused upon the summit to look upon the scene around 
us. The snow gliding insensibly from the mountains, or dis- 
charged in avalanches from the precipices which it overhung, 
filled the higher valleys with pure white glaciers, which were 
rifted and broken here and there, exposing chasms and pre- 
cipices from which gleamed the delicate blue of the half- 
formed ice. Sometimes, however, the neves spread over wide 
spaces without a rupture or wrinkle to break the smooth- 
ness of the superficial snow. The sky was now for the 
most part overcast, but through the residual blue spaces 
the sun at intervals poured light over the rounded bosses 
of the mountain. 

At half-past seven o'clock we reached another precipice 
of rock, to the left of which our route lay, and here 
Lauener proposed to have some refreshment ; after which 
we went on again. The clouds spread more and more, 
leaving at length mere specks and patches of blue 
between them. Passing some high peaks, formed by 



1858.] MONTE KOSA CAPPED. 125 

the dislocation of the ice, we came to a place where the 
neve was rent by crevasses, on the walls of which the stra- 
tification due to successive snow-falls was shown with 
great beauty and definition. Between two of these fissures 
our way now lay : the wall of one of them was hollowed 
out longitudinally midway down, thus forming a roof above 
and a ledge below, and from roof to ledge stretched a rail- 
ing of cylindrical icicles, as if intended to bolt them to- 
gether. A cloud now for the first time touched the 
summit of Monte Rosa, and sought to cling to it, but in a 
minute it dispersed in shattered fragments, as if dashed 
to pieces for its presumption. The mountain remained 
for a time clear and triumphant, but the triumph was 
short-lived : like suitors that will not be repelled, the dusky 
vapours came; repulse after repulse took place, and the 
sunlight gushed down upon the heights, but it was mani- 
fest that the clouds gained ground in the conflict. 

Until about a quarter past nine o'clock our work was 
mere child's play, a pleasant morning stroll along the 
flanks of the mountain ; but steeper slopes now rose 
above us, which called for more energy, and more care in 
the fixing of the feet. Looked at from below, some of 
these slopes appeared precipitous ; but we were too well 
acquainted with the effect of fore-shortening to let this 
daunt us. At each step we dug our batons into the deep 
snow. When first driven in, the batons* dipped from us, but 
were brought, as we walked forward, to the vertical, and 
finally beyond it at the other side. The snow was thus 
forced aside, a rubbing of the staff against it, and of 
the snow-particles against each other, being the conse- 
quence. We had thus perpetual rupture and regelation ; 
while the little sounds consequent upon rupture, reinforced 
by the partial echoes from the surfaces of the granules, 

* My staff was always the handle of an axe an inch or two longer 
than an ordinary walking-stick. 



126 THE "COMB" OE THE MOUNTAIN. [18-58. 

were blended together to a note resembling the lowing of 
cows. Hitherto I had paused a,t intervals to make notes, 
or to take an angle ; but these operations now ceased, not 
from want of time, but from pure dislike ; for when the 
eye has to act the part of a sentinel who feels that at 
any moment the enemy may be upon him ; when the body 
must be balanced with precision, and legs and arms, besides 
performing actual labour, must be kept in readiness for 
possible contingencies ; above all, when you feel that your 
safety depends upon yourself alone, and that, if your foot- 
ing gives way, there is no strong arm behind ready to be 
thrown between you and destruction ; under 'such circum- 
stances the relish for writing ceases, and you are willing 
to hand over your impressions to the safe keeping of 
memory. 

From the vast boss which constitutes the lower portion of 
Monte Rosa cliffy edges run upwards to the summit. Were 
the snow removed from these we should, I doubt not, see 
them as toothed or serrated crags, justifying the term 
" kamm" or " comb," applied to such edges by the Ger- 
mans. Our way now lay along such a kamm, the cliffs 
of which had, however, caught the snow, and been com- 
pletely covered by it, forming an edge like the ridge of a 
house-roof, which sloped steeply upwards. On the Lys- 
kamm side of the edge there was no footing, and, if a 
human body fell over here, it would probably pass through 
a vertical space of some thousands of feet, falling or rolling, 
before coming to rest. On the other side the snow-slope 
was less steep, but excessively perilous-looking, and inter- 
sected by precipices of ice. Dense clouds now enveloped 
us, and made our position far uglier than if it had been 
fairly illuminated. The valley below us was one vast caul- 
dron, filled with precipitated vapour, which came seething 
at times up the sides of the mountain. Sometimes this fog 
would partially clear away, and the light would gleam 



18.58.] ASCENT ALONG A COENICE. 127 

upwards from the dislocated glaciers. My guide continu- 
ally admonished me to make my footing sure, and to fix 
at each step my staff firmly in the consolidated snow. At 
one place, for a short steep ascent, the slope became hard 
ice, and our position a very ticklish one. We hewed our 
steps as we moved upwards, but were soon glad to deviate 
from the ice to a position scarcely less awkward. The wind 
had so acted upon the snow as to fold it over the edge of 
the kamm, thus causing it to form a kind of cornice, which 
overhung the precipice on the Lyskamm side of the moun- 
tain. This cornice now bore our weight: its snow had 
, become somewhat firm, but it was yielding enough to 
permit the feet to sink in it a little way, and thus secure us 
at least against the danger of slipping. Here also at each 
step we drove our batons firmly into the snow, availing 
ourselves of whatever help they could render. Once, 
while thus securing my anchorage, the handle of my 
hatchet went right through the cornice on which we stood, 
and, on withdrawing it, I could see through the aper- 
ture into the cloud-crammed gulf below. We continued 
ascending until we reached a rock protruding from the 
snow, and here we halted for a few minutes. Lauener 
looked upwards through the fog. " According to all de- 
scription," he observed, '" this ought to be the last kamm 
of the mountain; but in this obscurity we can see nothing." 
Snow began to fall, and we recommenced our journev, 
quitting the rocks and climbing again along the edge. 
Another hour brought us to a crest of cliffs, at which, 
to our comfort, the kamm appeared to cease, and other 
climbing qualities were demanded of us. 

On the Lyskamm side, as I have said, rescue would be 
out of the question, should the climber go over the edge. 
On the other side of the edge rescue seemed possible, 
though the slope, as stated already, was most dangerously 
steep. I now asked Lauener what he would have done, 



128 "DIE HOCHSTE SPIT7E." [1858. 

supposing my footing to have failed on the latter slope. 
He did not seem to like the question, but said that he 
should have considered well for a moment and then have 
sprung after me; but he exhorted me to drive all such 
thoughts away. I laughed at him, and this did more to 
set his mind at rest than any formal profession of courage 
could have done. We were now among rocks : we climbed 
cliffs and descended them, and advanced sometimes with 
our feet on narrow ledges, holding tightly on to other ledges 
by our fingers ; sometimes, cautiously balanced, we moved 
along edges of rock with precipices on' both sides. Once, 
in getting round a crag, Lauener shook a book from his 
pocket ; it was arrested by a rock about sixty or eighty feet 
below us. He wished to regain it, but I offered to supply 
its place, if he thought the descent too dangerous. He said 
he would make the trial, and parted from me. I thought 
it useless to remain idle. A cleft was before me, through 
which I must pass ; so, pressing my knees and back against 
its opposite sides, I gradually worked myself to the top. I 
descended the other face of the rock, and then, through 
a second ragged fissure, to the summit of another pinnacle. 
The highest point of the mountain was now at hand, sepa- 
rated from me merely by a short saddle, carved by wea- 
thering out of the crest of the mountain. I could hear 
Lauener clattering after me, through the rocks behind. I 
dropped down upon the saddle, crossed it, climbed the oppo- 
site cliff", and " die hochste Spitze " of Monte Rosa was won. 
Lauener joined me immediately, and we mutually con- 
gratulated each other on the success of the ascent. The 
residue of the bread and meat was produced, and a bottle of 
tea was also appealed to. Mixed with a little cognac, 
Lauener declared that he had never tasted anything like it. 
Snow fell thickly at intervals, and the obscurity was very 
great ; occasionally this would lighten and permit the sun 
to shed a ghastly dilute light upon us through the gleaming 



1858.] GLOOM ON THE SUMMIT. 129 

vapour. I put my boiling-water apparatus in order, and 
fixed it in a corner behind a ledge ; the shelter was, how- 
ever, insufficient, so I placed my hat above the vessel. 
The boiling point was 184- 9 2 Fahr., the ledge on which 
the instrument stood being 5 feet below the highest point 
of the mountain. 

The ascent from the Eiffel hotel occupied us about 
seven hours, nearly two of which were spent upon the 
kamm and crest. Neither of us felt in the least degree 
fatigued ; I, indeed, felt so fresh, that had another Monte 
Rosa been planted on the first, I should have continued 
the climb without hesitation, and with strong hopes of 
reaching the top. I experienced no trace of mountain 
sickness, lassitude, shortness of breath, heart-beat, or 
headache ; nevertheless the summit of Monte Rosa is 
15,284 feet high, being less than 500 feet lower than Mont 
Blanc. It is, I think, perfectly certain, that the rarefaction 
of the air at this height is not sufficient of itself to pro- 
duce the symptoms referred to ; physical exertion must be 
superadded. 

After a few fitful efforts to dispel the gloom, the sun 
resigned the dominion to the dense fog and the descending 
snow, which now prevented our seeing more than 15 or 
20 paces in any direction. The temperature of the crags 
at the summit, which had been shone upon by the un- 
clouded sun during the earlier portion of the day, was 
60 Fahr. ; hence the snow melted instantly wherever it 
came in contact with the rock. But some of it fell upon 
my felt hat, which had been placed to shelter the boiling- 
water apparatus, and this presented the most remarkable 
and beautiful appearance. The fall of snow was in fact a 
shower of frozen flowers. All of them were six-leaved ; 
some of the leaves threw out lateral ribs like ferns, some 
were rounded, others arrowy and serrated, some were close, 
others reticulated, but there was no deviation from the six- 
is 



130 "FROZEN FLOWERS." [1858. 

leaved type. Nature seemed determined to make us 
some compensation for the loss of all prospect, and thus 
showered down upon us those lovely blossoms of the frost ; 
and had a spirit of the mountain inquired my choice, the 
view, or the frozen flowers, I should have hesitated 
before giving up that exquisite vegetation. It was won- 
derful to think of, as well as beautiful to behold. Let us 
imagine the eye gifted with a microscopic power sufficient 
to enable it to see the molecules which composed these 
starry crystals ; to observe the solid nucleus formed and 
floating in the air ; to see it drawing towards it its allied 
atoms, and these arranging themselves as if they moved to 
music, and ended by rendering that music concrete. Surely 
such an exhibition of power, such an apparent demonstra- 
tion of a resident intelligence in what we are accustomed 
to call " brute matter," would appear perfectly miracu- 
lous. And yet the reality would, if we could see it, tran- 
scend the faucy. If the Houses of Parliament were built 
up by the forces resident in their own bricks and lithologic 
blocks, and without the aid of hodman or mason, there 
would be nothing intrinsically more wonderful in the pro- 
cess than in the molecular architecture which delighted us 
upon the summit of Monte Rosa. 

Twice or thrice had my guide warned me that we must 
think of descending, for the snow continued to fall heavily, 
and the loss of our track would be attended with imminent 
peril. We therefore packed upland clambered downward 
among the crags of the summit. We soon left these be- 
hind us, and as we stood once more upon the kamm, look- 
ing into the gloom beneath, an avalanche let loose from 
the side of an adjacent mountain shook the air with its 
thunder. We could not see it, could form no estimate of 
its distance, could only hear its roar, which coming to us 
through the darkness, had an undefinable element of 
horror in it. Lauener remarked, " I never hear those 



1858.] STARTLING AVALANCHE. 131 

things without a shudder ; the memory of my brother 
comes back to me at the same time." His brother, who 
was the best climber in the Oberland, had been literally 
broken to fragments by an avalanche on the slopes of the 
Jungfrau. 

We had been separate coining up, each having trusted 
to himself, but the descent was more perilous, because it is 
more difficult to fix the heel of the boot than the toe 
securely in the ice. Lauener was furnished with a rope, 
which he now tied round my waist, and forming a noose 
at the other end, he slipped it over his arm. This to me 
was a new mode of attachment. Hitherto my guides in 
dangerous places had tied the ropes round their waists 
also. Simond had done it on Mont Blanc, and Bennen on 
the Finsteraarhorn, proving thus their willingness to share 
my fate whatever that might be. But here Lauener had 
the power of sending me adrift at any moment, should his 
own life be imperilled. I told him that his mode of attach- 
ment was new to me, but he assured me that it would 
give him more power in case of accident. I did not see 
this at the time ; but neither did I insist on his attaching 
himself in the usual way. It could neither be called 
anger nor pride, but a warm flush ran through me as I 
remarked, that I should take good care not to test his 
power of holding me. I believe I wronged my guide by 
the supposition that he made the arrangement with refer- 
ence to his own safety, for all I saw of him afterwards 
proved that he would at any time have risked his life to 
save mine. The flush however did me good, by displacing 
every trace of anxiety, and the rope, I confess, was also a 
source of some comfort to me. We descended the kamm, I 
going first. " Secure your footing before you move," was 
,my guide's constant exhortation, " and make your staff firm 
at each step." We were sometimes quite close upon the 
rim of the kamm on the Lyskamm side, and we also 

K 2 



132 SPLENDID BLUE OF THE SNOW. [1858. 

followed the depressions which marked our track along the 
cornice. This I now tried intentionally, and drove the 
handle of my axe through it once or twice. At two 
places in descending we were upon the solid ice, and 
these were some of the steepest portions of the kamm. 
They were undoubtedly perilous, and the utmost caution 
was necessary in fixing the staff and securing the footing. 
These however once past, we felt that the chief danger 
was over. We reached the termination of the edge, and 
although the snow continued to fall heavily, and obscure 
everything, we knew that our progress afterwards was se- 
cure. There was pleasure in this feeling ; it was an agreeable 
variation of that grim mental tension to which I had been 
previously wound up, but which in itself was by no means 
disagreeable. 

I have already noticed the colour of the fresh snow upon 
the summit of the Stelvio pass. Since I observed it there 
it has been my custom to pay some attention to this point 
at all great elevations. This morning, as I ascended Monte 
Rosa, I often examined the holes made in the snow by our 
batons, but the light which issued from them was scarcely 
perceptibly blue. Now, however, a deep layer of fresh 
snow overspread the mountain, and the effect was magnifi- 
cent. Along the kamm I was continually surprised and 
delighted by the blue gleams which issued from the broken 
or perforated stratum of new snow ; each hole made by 
the staff was filled with a light as pure, and nearly as deep, 
as that of the unclouded firmament. When we reached 
the bottom of the kamm, Lauener came to the front, and 
tramped before me. As his feet rose out of the snow, and 
shook the latter off in fragments, sudden and wonderful 
gleams of blue light flashed from them. Doubtless the 
blue of the sky has much to do with mountain colouring, 
but in the present instance not only was there no blue sky, 
but the air was so thick with fog and descending snow- 



1858.] STIFLING HEAT. 133 

flakes, that we could not see twenty yards in advance of 
us. A thick fog, which wrapped the mountain quite 
closely, now added its gloom to the obscurity caused by 
the falling snow. Before we reached the base of the 
mountain the fog became thin, and the sun shone through 
it. There was not a breath of air stirring, and, though 
we stood ankle-deep in snow, the heat surpassed anything 
of the kind I had ever felt : it was the dead suffocating 
warmth of the interior of an oven, which encompassed us 
on all sides, and from which there seemed no escape. 
Our own motion through the air, however, cooled us con- 
siderably. We found the snow-bridges softer than in the 
morning, and consequently needing more caution ; but 
we encountered no real difficulty among them. Indeed 
it is amusing to observe the indifference with which a 
snow-roof is often broken through, and a traveller im- 
mersed to the waist in the jaws of a fissure. The effort 
at recovery is instantaneous ; half instinctively hands and 
knees are driven into the snow, and rescue is immediate. 
Fair glacier work was now before us ; after which we reached 
the opposite mountain-slope, which we ascended, and then 
went down the flank of the Biffelberg to our hotel. 
The excursion occupied us eleven and a half hours. 



(19.) 

On the afternoon of the llth I made an attempt alone 
to ascend the Kiffelhorn, and attained a considerable height ; 
but I attacked it from the wrong side, and the fading 
light forced me to retreat. I found some agreeable people 
at the hotel on my return. One clergyman especially, 
with a clear complexion, good digestion, and bad lungs 
of free, hearty, and genial manner made himself ex- 
tremely pleasant to us all. He appeared to bubble over 



134 A DIFFICULT DESCENT. [1858. 

with enjoyment, and with him and others on the morning 
of the 13th I walked to the Gorner Grat, as it lay on 
the way to my work. We had a glorious prospect from 
the summit : indeed the assemblage of mountains, snow, 
and ice, here within view is perhaps without a rival in the 
world.* I shouldered my axe, and saying " good-bye " 
moved away from my companions. 

" Are you going ? " exclaimed the clergyman. " Give 
me one grasp of your hand before we part." 

This was the signal for a grasp all round ; and the 
hearty human kindness which thus showed itself contri- 
buted that day to make my work pleasant to me. 

We proceeded along the ridge of the Kothe Kumme to 
a point which commanded a fine view of the glacier. The 
ice had been over these heights in ages past, for, although 
lichens covered the surfaces of the old rocks, they did not 
disguise the grooves and scratchings. The surface of the 
glacier was now about a thousand feet below us, and this 
it was our desire to attain. To reach it we had to descend 
a succession of precipices, which in general were weathered 
and rugged, but here and there, where the rock was 
durable, were fluted and grooved. Once or twice indeed 
we had nothing to cling to but the little ridges thus 
formed. We had to squeeze ourselves through narrow 
fissures, and often to get round overhanging ledges, where 
our main trust was in our feet, but where these had only 
ledges an inch or so in width to rest upon. These cases 
were to me the most unpleasant of all, for they compelled 
the arms to take a position which, if the footing gave way, 
would necessitate a wrench, for which I entertain consider- 
able abhorrence. We came at length to a gorge by which 
the mountain is rent from top to bottom, and into which 
we endeavoured to descend. We worked along its rim for 

* In 1858 Mr. E. W. Cooke made a pencil-sketch of this splendid 
panorama, which is the best and truest that I have yet seen. 



1858.] SINGULAK ICE-CAVE. 135 

a time, but found its smooth faces too deep. We retreated ; 
Lauener struck into another track, and while he tested 
it I sat down near some grass tufts, which flourished on 
one of the ledges, and found the temperature to be as 
follows : 

Temperature of rock . . . . 42 C. 
Of air an inch above the rock . . 32 
Of air a foot from rock . . . . 22 
Of grass . . . . . . . . 25 

The first of these numbers does not fairly represent the 
temperature of the rock, as the thermometer could be in 
contact with it only at one side at a time. It was differ- 
ences such as these between grass and stone, producing a 
mixed atmosphere of different densities, that weakened the 
sound of the falls of the Orinoco, as observed and explained 
by Humboldt. 

By a process of "trial and error" we at length reached 
the ice, after two hours had been spent in the effort to 
disentangle ourselves from the crags. The glacier is 
forcibly thrust at this place against the projecting base 
of the mountain, and the structure of the ice corre- 
spondingly developed. Crevasses also intersect the ice, 
and the blue veins cross them at right angles. I as- 
cended the glacier to a region where the ice was com- 
pressed and greatly contorted, and thought that in some 
cases I could see the veins crossing the lines of stra- 
tification. Once my guide drew my attention to what he 
called " ein sonderbares Loch" On one of the slopes an 
archway was formed which appeared to lead into the body 
of the glacier. We entered it, and explored the cavern to 
its end. The walls were of transparent blue ice, singularly 
free from air-bubbles ; but where the roof of the cavern 
was thin enough to allow the sun to shine feebly through 
it, the transmitted light was of a pink colour. My guide 



136 STEUCTUEE AND STEATA. [1858. 

expressed himself surprised at " den rotliliclien Schein." At 
one place a plate of ice had been placed like a ceiling 
across the cavern ; but owing to lateral squeezing it had 
been broken so as to form a V. I found some air-bubbles 
in this ice, and in all cases they were associated with 
blebs of water. A portion of the " ceiling," indeed, was 
very full of bubbles, and was at some places reduced, by 
internal liquefaction, to a mere skeleton of ice, with water- 
cells between its walls. 

High up the glacier (towards the old Weissthor) the 
horizontal stratification is everywhere beautifully shown. 
I drew my guide's attention to it, and he made the 
remark that the perfection of the lower ice was due to the 
pressure of the layers above it. " The snow by degrees 
compressed itself to glacier." As we approached one of 
the tributaries on the Monte Rosa side, where great pres- 
sure came into play, the stratification appeared to yield 
and the true structure to cross it at those places where 
it had yielded most. As the place of greatest pressure 
was approached, the bedding disappeared more and more, 
and a clear vertical structure was finally revealed. 



1858.] GENERATION OF CLOUDS. 137 



THE GORNER GRAT AND THE RIFFELHORN. 
MAGNETIC PHENOMENA. 

(20.) 

AT an early hour on Saturday, the 14th of August, I 
heard the servant exclaim, "Das Wetter ist wunderschon ! " 
which good news caused me to spring from my bed and 
prepare to meet the morn. The range of summits at the 
opposite side of the valley of St. Nicholas was at first 
quite clear, but as the sun ascended light cumuli formed 
round them, increasing in density up to a certain point ; 
below these clouds the air of the valley was transparent ; 
above them the air of heaven was still more so ; and thus 
they swung midway between heaven and earth, ranging 
themselves in a level line along the necks of the moun- 
tains. 

It might be supposed that the presence of the sun 
heating the air would tend to keep it more transparent, 
by increasing its capacity to dissolve all visible cloud ; and 
this indeed is the true action of the sun. But it is not 
the only action. His rays, as he climbed the eastern 
heaven, shot more and more deeply into the valley of 
St. Nicholas, the moisture of which rose as invisible 
vapour, remaining unseen as long as the air possessed 
sufficient warmth to keep it in the vaporous state. High 
up, however, the cold crags which had lost their heat 
by radiation the night before, acted like condensers 
upon the ascending vapour, and caused it to curdle into 
visible fog. The current, however, continued ascen- 
sional, and the clouds were slowly lifted above the tallest 
peaks, where they arranged themselves in fantastic forms, 
shifting and changing shape as they gradually melted away. 



188 THE EOCKS WAKMED. [1858. 

One peak stood like a field-officer with his cap raised above 
his head, others sent straggling cloud-balloons upwards ; 
but on watching these outliers they were gradually seen 
to disappear. At first they shone like snow in the sun- 
light, but as they became more attenuated they changed 
colour, passing through a dull red to a dusky purple hue, 
until finally they left no trace of their existence. 

As the day advanced, warming the rocks, the clouds 
wholly disappeared, and a hyaline air formed the setting 
of both glaciers and mountains. I climbed to the Gorner 
Grat to obtain a general view of the surrounding scene. 
Looking towards the origin of the Gorner glacier the view 
was bounded by a wide col, upon which stood two lovely 
rounded eminences enamelled with snow of perfect purity. 
They shone like burnished silver in the sunlight, as if 
their surfaces had been melted and recongealed to frosted 
mirrors from which the rays were flung. To the right 
of these were the bounding crags of Monte Rosa, and 
then the body of the mountain itself, with its crest of 
crag and coat of snows. To the right of Monte Kosa, 
and almost rivalling it in height, was the vast mass 
of the Lyskamm, a rough and craggy mountain, to 
whose ledges clings the snow which cannot grasp its 
steeper walls, sometimes leaning over them in impending 
precipices, which often break, and send wild avalanches 
into the space below. Between the Lyskamm and Monte 
Kosa lies a large wide valley into which both mountains 
pour their snows, forming there the Western glacier of 
Monte Rosa * a noble ice stream, which from its mag- 
nitude and permanence deserves to impose its name 
upon the trunk glacier. It extends downwards from the 
col which unites the two mountains ; riven and broken 
at some places, but at others stretching white and pure 

* [Now called, in the Federal map, the ' Grenz glacier.' L. C. T.] 



1858.] SCENE FROM THE GORNER GRAT. 139 

down to its snow-line, where the true glacier emerges from 
the neve. From the rounded shoulders of the Twin Castor 
a glacier descends, at first white and shining, then sud- 
denly broken into faults, fissures, and precipices, which 
are afterwards repaired, and the glacier joins that of 
Monte Kosa before the junction of the latter with the 
trunk stream. Next came a boss of rock, with a secondary 
glacier clinging to it as if plastered over it, and after it 
the Schwarze glacier, bounded on one side by the Breithorn, 
and on the other by the Twin Pollux. This glacier is of 
considerable magnitude. Over its upper portion rise the 
Twin eminences, pure and white ; then follows a smooth and 
undulating space, after passing which the neve is torn 
up into a collection of peaks and chasms; these, how- 
ever, are mended lower down, and the glacier moves 
smoothly and calmly to meet its brothers in the main 
valley. Next comes the Trifti glacier,* embraced on all 
sides by the rocky arms of the Breithorn ; its mass is not 
very great, but it descends in a graceful sweep, and 
exhibits towards its extremity a succession of beautiful 
bands. Afterwards we have the glacier of the Petit 
Mont Cervin and those of St. Theodule, which latter are 
the last that empty their frozen cargoes into the valley 
of the Gorner. All the glaciers here mentioned are 
welded together to a common trunk which squeezes itself 
through the narrow defile at the base of the KifFelhorn. 
Soon afterwards the moraines become confused, the glacier 
drops steeply to its termination, and ploughs up the 
meadows in front of it with its irresistible share. 

In a line with the Riffelhorn, and rising over the 
latter so high as to make it almost vanish by comparison, 
was the Titan obelisk of the Matterhorn, from the base of 
which the Furgge glacier struggles downwards. On the 

* I take this name from Studer's map. Sometimes, however, I have 
called it the " Breithorn glacier." 



140 COMPASS AT FAULT. [1858. 

other side are the Zmutt glacier, the Schonbiihl, and the 
Hochwang, from the Dent Blanche ; the Gabelhorn and 
Trift glaciers, from the summits which bear those names. 
Then come the glaciers of the Weisshorn. Describing a 
curve still farther to the right we alight on the peaks 
of the Mischabel, dark and craggy precipices from this side, 
though from the ^Eggischhorn they appear as cones of snow. 
Sweeping by the Alphubel, the Allaleinhorn, the Rymp- 
fischorn, and Strahlhorn all of them majestic we reach 
the pass of the Weissthor, and the ' Cima di Jazzi. This 
completes the glorious circuit within the observer's view. 

I placed my compass upon a piece of rock to find the 
bearing of the Gorner glacier, and was startled at seeing 
the sun and it at direct variance. What the sun declared 
to be north, the needle affirmed to be south. I at first 
supposed that the maker had placed the S where the N 
ought to be, and vice versa. On shifting my position, 
however, the needle shifted also, and I saw immediately 
that the effect was due to the rock of the Grat. Some- 
times one end of the needle dipped forcibly, at other 
places it whirled suddenly round, indicating an entire 
change of polarity. The rock was evidently to be re- 
garded as an assemblage of magnets, or as a single 
magnet full of " consequent points." A distance of trans- 
port not exceeding an inch was, in some cases, sufficient 
to reverse the position of the needle. I held the needle 
between the two sides of a long fissure a foot wide. 
The needle set along the fissure at some places, while at 
others it set across it. Sometimes a little jutting knob 
would attract the north end of the needle, while a closely 
adjacent little knob would forcibly repel it, and attract 
the south end. One extremity of a ledge three feet long 
was north magnetic, the other end was south magnetic, 
while a neutral point existed midway between the two, the 
ledge having therefore the exact polar arrangement of an 



1858.] MAGNETISM OF BOOKS. 141 

ordinary bar-magnet. At the highest point of the rock 
the action appeared to be most intense, but I also found 
an energetic polarity in a mass at some distance below the 
summit. 

Eemembering that Professor Forbes had noticed some 
peculiar magnetic effect upon the Eiffelhorn, I resolved to 
ascend it. Descending from the Grat we mounted the 
rocks which form the base of the horn ; these are soft and 
soapy from the quantity of mica which they contain ; 
the higher rocks of the horn are, however, very dense and 
hard. The ascent is a pleasant bit of mountain practice. 
We climbed the walls of rock, and wound round the ledges, 
seeking the assailable points. I tried the magnetic condi- 
tion of the rocks as we ascended, and found it in general 
feeble. In other respects the Biffelhorn is a most re- 
markable mass. The ice of the Gorner glacier of former 
ages, which rose hundreds, perhaps thousands of feet above 
its present level, encountered the horn in its descent, and 
was split by the latter, a diversion of the ice along the 
sides of the peak being the consequence. Portions of the 
vertical walls of the horn are polished by this action as if 
they had come from the hands of a lapidary, and the 
scratchings are as sharp and definite as if drawn by 
points of steel. I never saw scratchings so perfectly 
preserved : the finest lines are as clear as the deepest, a 
consequence of the great density and durability of the 
rock. The latter evidently contains a good deal of iron, 
and its surface near the summit is of the rich brown red 
due to the peroxide of the metal. When we fairly got 
among the precipices we left our hatchets behind us, trust- 
ing subsequently to our hands and feet alone. Squeezing, 
creeping, clinging, and climbing, in due time we found 
ourselves upon the summit of the horn. 

A pile of stones had been erected near the point where 
we gained the top. I examined the stones of this pile, 



142 ASCENT OF THE KIFFELHORN. [1858. 

and found them strongly polar. The surrounding rocks 
also showed a violent action, the needle oscillating quickly, 
and sometimes twirling swiftly round upon a slight change 
of position. The fragments of rock scattered about were 
also polar. Long ledges showed north magnetism for a 
considerable length, and again for an equal length south 
magnetism. Two parallel masses separated from each 
other by a fissure, showed the same magnetic distribution. 
While I was engaged at one end of the horn, Lauener 
wandered to the other, on which- stood two or three 
hommes de pierres. He was about disturbing some of the 
stones, when a yell from me surprised him. In fact, 
the thought had occurred to me that the magnetism of 
the horn had been developed by lightning striking upon 
it, and my desire was to examine those points which were 
most exposed to the discharge of the atmospheric electri- 
city ; hence my shout to my guide to let the stones alone. 
I worked towards the other end of the horn, examining 
the rocks in my way. Two weathered prominences, which 
seemed very likely recipients of the lightning, acted vio- 
lently upon the needle. I sometimes descended a little 
way, and found that among the rocks below the summit 
the action was greatly enfeebled. On reaching another 
very prominent point, I found its extremity all north 
polar, but at a little distance was a cluster of consequent 
points, among which the transport of a few inches was 
sufficient to turn the needle round and round. 

The piles of stone at the Zermatt end of the horn did 
not seem so strongly polar as the pile at the other end, 
which was higher ; still a strong polar action was mani- 
fested at many points of the surrounding rocks. Having 
completed the examination of the summit, I descended 
the horn, and examined its magnetic condition as I went 
along. It seemed to me that the jutting prominences 
always exhibited the strongest action. I do not indeed 



1858.] 



MAGNETISM OF THE HORN. 



143 



remember any case in which a strong action did not ex- 
hibit itself at the ends of the terraces which constitute 
the horn. In all cases, however, the rock acted as a 
number of magnets huddled confusedly together, and not 
as if its entire mass was endowed with magnetism of one 
kind. 

On the evening of the same day I examined the lower 
spur of the Riffelhorn. Amid its fissures and gulleys one 
feels as if wandering through the ruins of a vast castle or 
fortification ; the precipices are so like walls, and the 
scratching and polishing so like what might be done by 
the hands of man. I found evidences of strong polar 
action in some of the rocks low down. In the same con- 
tinuous mass the action would sometimes exhibit itself 
over an area of small extent, while the remainder of the 
rock showed no appreciable action. Some of the boulders 
cast down from the summit exhibited a strong and varied 
polarity. Fig. 8 is a sketch of one of these ; the barbed 
end of each arrow repre- 
sents the north end of the 
needle, which assumed 
the various positions 
shown in the figure. Mid- 
way down the spur I 
lighted upon a trans-., 
verse wall of rock, which 
formed in earlier ages 
the boundary of a lateral outlet of the Gorner glacier. It 
was red and hard, weathered rough at some places, and 
polished smooth at others. The lines were drawn finely 
upon it, but its outer surface appeared to be peeling off 
like a crust ; the polished layer rested upon the rock like 
a kind of enamel. The action of the glacier appeared to 
resemble that of the break of a locomotive upon rails, both 
being cases of exfoliation brought about by pressure and 




144 THE MAGNETIC FOKCE. [1858. 

friction. This wall measured twenty-eight yards across, 
and one end of it, for a distance of ten or twelve yards, was 
all north polar ; the other end for a similar distance was 
south polar, but there was a pair of consequent points at 
its centre. 

To meet the case of my young readers, I will here 
say a few words about the magnetic force. The common 
magnetic needle points nearly north and south ; and if a 
bit of iron be brought near to either end of the needle, 
they will mutually attract each other. A piece of lead 
will not show this effect, nor will copper, gold, nor silver. 
Iron, in fact, is a magnetic metal, which the others are not. 
It is to be particularly observed, that the bit of iron at- 
tracts both ends of the needle when it is presented to them 
in succession ; and if a common steel sewing needle be 
substituted for the iron it will be seen that it also has the 
power of attracting both ends of the magnetic needle. But 
if the needle be rubbed once or twice along one end 
of a magnet, it will be found that one of its ends will 
afterwards repel a certain end of the magnetic needle and 
attract the other. By rubbing the needle on the magnet, 
we thus develop both attraction and repulsion, and this 
double action of the magnetic force is called its polarity ; 
thus the steel which was at first simply magnetic, is now 
magnetic and polar. 

It is the aim of persons making magnets, that each mag- 
net should have but two poles, at its two ends; it is, however, 
easy to develop in the same piece of steel several pairs of 
poles ; and if the magnetization be irregular, this is some- 
times done when we wish to avoid it. These irregular 
poles are called consequent points. 

Now I want my young reader to understand that it is 
not only because the rocks of the Gorner Grat and Riffel- 
horn contain iron, that they exhibit the action which I 
have described. They are not only magnetic, as common 



1858.] BEARINGS FROM THE RIFFELHORN. 145 

iron is, but, like the magnetized steel needle, they are mag- 
netic and polar. And these poles are irregularly dis- 
tributed like the " consequent points " to which I have 
referred, and this is the reason why I have used the term. 
Professor Forbes, as I have already stated, was the first to 
notice the effect of the Riffelhorn upon the magnetic needle, 
but he seems to have supposed that the entire mass of the 
mountain exercised " a local attraction " upon the needle ; 
(upon which end he does not say). To enable future observers 
to allow for this attraction, he took the bearing of several of 
the surrounding mountains from the Eiffelhorn ; but it is 
very probable that had he changed his position a few inches, 
and perfectly certain had he changed it a few yards, he would 
have found a set of bearings totally different from those 
which he has recorded. The close proximity and irregular 
distribution of its consequent points would prevent the 
Riffelhorn from exerting any appreciable influence on a 
distant needle, as in this case the local poles would effectu- 
ally neutralize each other. 



(21.) 

On the morning of the 1 5th the Riffelberg was swathed 
in a dense fog, through which heavy rain showered inces- 
santly. Towards one o'clock the continuity of the gray 
mass was broken, and sky-gleams of the deepest blue 
were seen through its apertures ; these would close up 
again, and others open elsewhere, as if the fog were 
fighting for existence with the sun behind it. The sun, 
however, triumphed, the mountains came more and more 
into view, and finally the entire air was swept clear. I 
went up to the Gorner Grat in the afternoon, and examined 
more closely the magnetism of its rocks ; here, as on the 
Riffelhorn, I found it most pronounced at the jutting 

L 



146 MONT CERVIN AS CLOUD-MAKEE. [1858. 

prominences of the Grat. Can it be that the superior ex- 
posure is more favourable to the formation of the magnetic 
oxide of iron ? I secured a number of fragments, which I 
still possess, and which act forcibly upon a magnetic needle. 
The sun was near the western horizon, and I remained 
alone upon the Grat to see his last beams illuminate the 
mountains, which, with one exception, were without a trace 
of cloud. This exception was the Matterhorn, the appear- 
ance of which was extremely instructive. The obelisk 
appeared to be divided in two halves by a vertical line 
drawn from its summit half way down, to the windward of 
which we had the bare cliffs of the mountain ; and to the 
left of it a cloud which appeared to cling tenaciously to the 
rocks. In reality, however, there was no clinging ; the con- 
densed vapour incessantly got away, but it was ever 
renewed, and thus a river of cloud had been sent from 
the mountain over the valley of Aosta. The wind in fact 
blew lightly up the valley of St. Nicholas charged with 
moisture, and when the air that held it rubbed against the 
cold cone of the Matterhorn the vapour was chilled and 
precipitated in his lee. The summit seemed to smoke 
sometimes like a burning mountain ; for immediately after 
its generation, the fog was drawn away in long filaments 
by the wind. As the sun sank lower the ruddiness of his 
light augmented, until these filaments resembled streamers 
of flame. The sun sank deeper, the light was gradually 
withdrawn, and where it had entirely vanished it left the 
mountain like a desolate old man whose 

" hoary hair 
Stream'd like a meteor in the troubled air." 

For a moment after the sun had disappeared the scene was 
amazingly grand. The distant west was ruddy, copious gray 
smoke-wreaths were wafted from the mountains, while high 
overhead, in an atmospheric region which seemed perfectly 
motionless, floated a broad thin cloud, dyed with the richest 



1858.] CELLS IN THE ICE. 147 

iridescences. The colours were of the same character as 
those which I had seen upon the Aletschhorn, being due to 
interference, and in point of splendour and variety far 
exceeded anything ever produced by the mere coloured 
light of the setting sun. 

On the 16th I was early upon the glacier. It had frozen 
hard during the night, and the partially liberated streams 
flowed, in many cases, over their own ice. I took some 
clear plates from under the water, and found in them 
numerous liquid cells, each associated with an air-bubble 
or a vacuous spot. The most common shape of the cells 
was a regular hexagon, but there were all forms between 
the perfect hexagon and the perfect circle. Many cells 
had also crimped borders, intimating that their primitive 
form was that of a flower with six leaves. A plate taken 
from ice which was defended from the sunbeams by the 
shadow of a rock had no such cells ; so that those that I 
observed were probably due to solar radiation. 

My first aim was to examine the structure of the 
Gornerhorn glacier,* which descends the breast of Monte 
Rosa until it is abruptly cut off by the great Western glacier 
of the mountain.f Between them is a moraine which is at 
once terminal as regards the former, and lateral as regards 
the latter. The ice is veined vertically along the mo- 
raine, the direction of the structure being parallel to the 
latter. I ascended the glacier, and found, as I retreated 
from the place where the thrust was most violent, that the 
structure became more feeble. From the glacier I passed 
to the rocks called " aufder Platte" so as to obtain a general 
view of its terminal portion. The gradual perfecting of 
the structure as the region of pressure was approached 
was very manifest : the ice at the end seemed to wrinkle 

* [Now called, in the Federal map, the " Monte Eosa glacier." Gorner- 
horn is an old local name for the central mass of Monte Eosa. L.C.T.] 
t [See p. 138, footnote.] 

L 2 



148 STKUCTUBE OF THE ICE. [1858. 

up in obedience to the pressure, the structural furrows, 
from being scarcely visible, became more and more 
decided, and the lamination underneath correspondingly 
pronounced, until it finally attained a state of great per- 
fection. 

I now quitted the rocks and walked straight across 
the Western glacier of Monte Eosa to its centre, where 
I found the structure scarcely visible. I next faced the 
Gorner Grat, and walked down the glacier towards the 
moraine which divides it from the Gorner glacier. The 
mechanical conditions of the ice here are quite evident ; 
each step brought me to a place of greater pressure, and 
also to a place of more highly developed structure, until 
finally near to the moraine itself, and running parallel to 
it, a magnificent lamination was developed. Here the 
superficial groovings could be traced to great distances, 
and beside the moraine were boulders poised on pedestals 
of ice through which the blue veins ran. At some places 
the ice had been weathered into laminae not more than 
a line in thickness. 

I now recrossed the Monte Rosa glacier to its junction 
with the Schwartze glacier, which descends between the 
Twins and Breithorn. The structure of the Monte Rosa 
glacier is here far less pronounced than at the other 
side, and the pressure which it endures is also manifestly 
less; the structure of the Schwartze glacier is fairly 
developed, being here parallel to its moraine. The cliffs ot 
the Breithorn are much exposed to weathering action, and 
boulders are copiously showered down upon the adjacent 
ice. Between the Schwartze glacier and the glacier 
which descends from the breast of the Breithorn itselt 
these blocks ride upon a spine of ice, and form a moraine 
of grand proportions. From it a fine view of the glacier 
is attainable, and the gradual development of its structure 
as the region of maximum pressure is approached is very 






1858.] TEIBUTAKIES EXPLORED. 149 

plain. A number of gracefully curved undulations sweep 
across the Breithorn glacier, which are squeezed more 
closely together as the moraine is approached. All the 
glaciers that descend from the flanking mountains of the 
Gorner valley are suddenly turned aside where they meet 
the great trunk stream, and are reduced by the pressure 
to narrow stripes of ice separated from each other by 
parallel moraines. 

I ascended the Breithorn glacier to the base of an ice- 
fall, on one side of which I found large crumples produced 
by the pressure, the veined structure being developed at 
right angles to the direction of the latter. No such struc- 
ture was visible above this place. The crumples were cut 
by fissures, perpendicular to which the blue veins ran. 
I now quitted the glacier, and clambered up the adjacent 
alp, from which a fine view of the general surface was 
attainable. As in the case of the Gornerhorn glacier, the 
gradual perfecting of the structure was very manifest ; 
the dirt, which first irregularly scattered over the surface, 
gradually assumed a, striated appearance, and became 
more and more decided as the moraine was approached. 
Descending from the alp, I endeavoured to measure 
some of the undulations; proceeding afterwards to the 
junction of the Breithorn glacier with that of St. Theodule. 
The end of the latter appears to be crumpled by its 
thrust against the former, and the moraine between them, 
instead of being raised, runs along a hollow which is 
flanked by the crumples on either side. The Breithorn 
glacier became more and more attenuated, until finally it 
actually vanished under its own moraines. On the sides 
of the crevasses, by which the Theodule glacier is here 
intersected, I thought I could plainly see two systems of 
veins cutting each other at an angle of fifteen or twenty 
degrees. Reaching the Gorner glacier, at a place where 
its dislocation was very great, I proceeded down it past 



150 TEMPTATION. [1858. 

the RifFelhorn, to a point where it seemed possible to scale 
the opposite mountain wall. Here I crossed the glacier, 
treading with the utmost caution along the combs of ice, 
and winding through the entanglement of crevasses until 
the spur of the Riffelhorn was reached ; this I climbed 
to its summit, and afterwards crossed the green alp to 
our hotel. 

The foregoing good day's work was rewarded by a sound 
sleep at night. The tourists were called in succession 
next morning, but after each call I instantly subsided 
into deep slumber, and thus healthily spaced out the 
interval of darkness. Day at length dawned and gradually 
brightened. I looked at my watch and found it twenty 
minutes to six. My guide had been lent to a party of 
gentlemen who had started at three o'clock for the summit 
of Monte Rosa, and he had left with me a porter who 
undertook to conduct me to one of the adjacent glaciers. 
But as I looked from my window the unspeakable beauty 
of the morning filled me with a longing to see the world 
from the top of Monte Rosa. I was in exceedingly 
good condition could I not reach the summit alone? 
Trained and indurated as I had been, I felt that the thing 
was possible ; at all events I could try, without attempting 
anything which was not clearly within my power. 



1858.] A LIGHT SCEIP. 151 

SECOND ASCENT OF MONTE EOS A, 1858. 

(22.) 

WHETHER my exercise be mental or bodily, I am always 
most vigorous when cool. During my student life in 
Germany, the friends who visited me always complained 
of the low temperature of my room, and here among 
the Alps it was no uncommon thing for me to wander 
over the glaciers from morning till evening in my shirt- 
sleeves. My object now was to go as light as possible, 
and hence I left my coat and neckcloth behind me, trusting 
to the sun and my own motion to make good the calorific 
waste. After breakfast I poured what remained of my tea 
into a small glass bottle, an ordinary demi-bouteille, in 
fact ; the waiter then provided me with a ham sandwich, 
and, with my scrip thus frugally furnished, I thought the 
heights of Monte Kosa might be won. I had neither 
brandy nor wine, but I knew the immense amount of me- 
chanical force represented by four ounces of bread and 
ham, and I therefore feared no failure from lack of nutri- 
ment. Indeed, I am inclined to think that both guides 
and travellers often impair their vigour and render them- 
selves cowardly and apathetic by the incessant "refreshing" 
which they deem it necessary to indulge in on such 
occasions. 

The guide whom Lauener intended for me was at the 
door ; I passed him and desired him to follow me. This 
he at first refused to do, as he did not recognise me in my 
shirt-sleeves ; but his companions set him right, and he 
ran after me. I transferred my scrip to his shoulders, and 
led the way upward. Once or twice he insinuated that that 
was not the way to the Schwarze-See, and was probably 
perplexed by my inattention. From the summit of the 



152 THE GUIDE EXPOSTULATES. [1858. 

ridge which bounds the Gorner glacier the whole grand 
panorama revealed itself, and on the higher slopes of Monte 
Rosa go high, indeed, as to put all hope of overtaking 
them, or even coming near them, out of the question a 
row of black dots revealed the company which had started 
at three o'clock from the hotel. They had made remark- 
ably good use of their time, and I was afterwards informed 
that the cause of this was the intense cold, which compelled 
them to keep up the proper supply of heat by increased 
exertion. I descended swiftly to the glacier, and made for 
the base of Monte Rosa, my guide following at some dis- 
tance behind me. One of the streams, produced by super- 
ficial melting, had cut for itself a deep wide channel in the 
ice ; it was not too wide for a spring, and with the aid of 
a run I cleared it and went on. Some minutes afterwards 
I could hear the voice of my companion exclaiming, in a 
tone of expostulation, " No, no, I won't follow you there." 
He however made a circuit, and crossed the stream ; I 
waited for him at the place where the Monte Rosa glacier 
joins the rock, " auf der Platte" and helped him down the 
ice-slope. At the summit of these rocks I again waited for 
him. He approached me with some excitement of manner, 
and said that it now appeared plain to him that I intended 
to ascend Monte Rosa, but that he would not go with me. 
I asked him to accompany me to the summit of the next 
cliff, which he agreed to do ; and I found him of some ser- 
vice to me. He discovered the faint traces of the party in 
advance, and, from his greater experience, could keep them 
better in view than I could. We lost them, however, near 
the base of the cliff at which we aimed, and I went on, 
choosing as nearly as I could remember the route followed 
by Lauener and myself a week previously, while my guide 
took another route, seeking for the traces. The glacier 
here is crevassed, and I was among the fissures some dis- 
tance in advance of my companion. Fear was manifestly 



1858.] THE GUIDE HALTS. 153 

getting the better of him, and he finally stood still, ex- 
claiming, "No man can pass there." At the same mo- 
ment I discovered the trace, and drew his attention to it ; 
he approached me submissively, said that I was quite 
right, and declared his willingness to go on. We climbed 
the cliff, and discovered the trace in the snow above it. 
Here I transferred the scrip and telescope to my own 
shoulders, and gave my companion a cheque for five francs. 
He returned, and I went on alone. 

The sun and heaven were glorious, but the cold 
was nevertheless intense, for it had frozen bitterly the 
night before. The mountain seemed more noble and 
lovely than when I had last ascended it ; and as I climbed 
the slopes, crossed the shining cols, and rounded the vast 
snow-bosses of the mountain, the sense of being alone lent 
a new interest to the glorious scene. I followed the track 
of those who preceded me, which was that pursued by 
Lauener and myself a week previously. Once I deviated 
from it to obtain a glimpse of Italy over the saddle which 
stretches from Monte Rosa to the Lyskamm. Deep be- 
low me was the valley, with its huge and dislocated neve, 
and the slope on which I hung was just sufficiently steep 
to keep the attention aroused without creating anxiety. 
I prefer such a slope to one on which the thought of 
danger cannot be entertained. I become more weary 
upon a dead level, or in walking up such a valley as 
that which stretches between Visp and Zermatt, than on 
a steep mountain side. The sense of weariness is often 
no index to the expenditure of muscular force : the 
muscles may be charged with force, and, if the nervous 
excitant be feeble, the strength lies dormant, and we 
are tired without exertion. But the thought of peril 
keeps the mind awake, and spurs the muscles into 
action ; they move with alacrity and freedom, and the 
time passes swiftly and pleasantly. 



154 LEFT ALONE. [1858. 

Occupied with my own thoughts as I ascended, I 
sometimes unconsciously went too quickly, and felt the 
effects of the exertion. I then slackened my pace, 
allowing each limb an instant of repose as I drew it out 
of the snow, and found that in this way walking became 
rest. This is an illustration of the principle which runs 
throughout nature to accomplish physical changes, time 
is necessary. Different positions of the limb require 
different molecular arrangements; and to pass from one 
to the other requires time. By lifting the leg slowly and 
allowing it to fall forward by its own gravity, a man may 
get on steadily for several hours, while a very slight addi- 
tion to this pace may speedily exhaust him. Of course 
the normal pace differs in different persons, but in all 
the power of endurance may be vastly augmented by the 
prudent outlay of muscular force. 

The sun had long shone down upon me with intense 
fervour, but I now noticed a strange modification of the 
light upon the slopes of snow. I looked upwards, and saw 
a most gorgeous exhibition of interference-colours. A light 
veil of clouds had drawn itself between me and the sun, 
and this was flooded with the most brilliant dyes. Orange, 
red, green, blue all the hues produced by diffraction were 
exhibited in the utmost splendour. There seemed a ten- 
dency to form circular zones of colour round the sun, but 
the clouds were not sufficiently uniform to permit of this, 
and they were consequently broken into spaces, each 
steeped with the colour due to the condition of the cloud 
at the place. Three times during my ascent similar veils 
drew themselves across the sun, and at each passage the 
splendid phenomena were renewed. As I reached the 
middle of the mountain an avalanche was let loose from 
the sides of the Lyskamm ; the thunder drew my eyes to 
the place ; I saw the ice move, but it was only the tail 01 
the avalanche ; still the volume of sound told me that it 



1858.] GIDDINESS ON THE KAMM. 155 

was a huge one. Suddenly the front of it appeared from 
behind a projecting rock, hurling its ice-masses with fury 
into the valley, and tossing its rounded clouds of ice-dust 
high into the atmosphere. A wild long-drawn sound, 
multiplied by echoes, now descended from the heights 
above me. It struck me at first as a note of lamentation, 
and I thought that possibly one of the party which was 
now near the summit had gone over the precipice. On 
listening more attentively I found that the sound shaped 
itself into an English " hurrah ! " I was evidently nearing 
the party, and on looking upwards I could see them, but 
still at an immense height above me. The summit still 
rose before them, and I therefore thought the cheer prema- 
ture. A precipice of ice was now in front of me, around 
which I wound to the right, and in a few minutes found 
myself fairly at the bottom of the Kamm. 

I paused here for a moment, and reflected on the work 
before me. My head was clear, my muscles in perfect 
condition, and I felt just sufficient fear to render me careful. 
I faced the Kamm, and went up slowly but surely, and 
soon heard the cheer which announced the arrival of the 
party at the summit of the mountain. It was a wild, weird, 
intermittent sound, swelling or falling as the echoes re- 
inforced or enfeebled it. In getting through the rocks 
which protrude from the snow at the base of the last spur 
of the mountain, I once had occasion to stoop my 
head, and, on suddenly raising it, my eyes swam as they 
rested on the unbroken slope of snow at my left. The 
sensation was akin to giddiness, but I believe it was chiefly 
due to the absence of any object upon the snow upon 
which I could converge the axes of my eyes. Up to 
this point I had eaten nothing. I now unloosed my 
scrip, and had two mouthfuls of sandwich and nearly the 
whole of the tea that remained. I found here that my 
load, light as it was, impeded me. When fine balancing 



156 SCRIP LEFT BEHIND. [1858. 

is necessary, the presence of a very light load, to which 
one is unaccustomed, may introduce an element of 
danger, and for this reason I here left the residue of 
my tea and sandwich behind me. A long, long edge was 
now in front of me, sloping steeply upwards. As I com- 
menced the ascent of this, the foremost of those whose 
cheer had reached me from the summit some time pre- 
viously, appeared upon the top of the edge, aod the whole 
party was seen immediately afterwards dangling on the 
Kamm. We mutually approached' each other. Peter 
Bohren, a well-known Oberland guide, came first, and 
after him came the gentleman in his immediate charge. 
Then came other guides with other gentlemen, and 
last of all my guide, Lauener, with his strong right 
arm round the youngest of the party. We met where a 
rock protruded through the snow. The cold smote my 
naked throat bitterly, so to protect it I borrowed a hand- 
kerchief from Lauener, bade my new acquaintances good 
bye, and proceeded upwards. I was soon at the place 
where the snow-ridge joins the rocks which constitute the 
crest of the mountain ; through these my way lay, every 
step I took augmenting my distance from all life, and 
increasing my sense of solitude. I went up and down the 
cliffs as before, round ledges, through fissures, along edges 
of rock, over the last deep and rugged indentation, and up 
the rocks at its opposite side, to the summit. 

A world of clouds and mountains lay beneath me. Switz- 
erland, with its pomp of summits, was clear and grand ; 
Italy was also grand, but more than half obscured. Dark 
cumulus and dark crag vied in savagery, while at other 
places white snows and white clouds held equal rivalry. 
The scooped valleys of Monte Kosa itself were magni- 
ficent, all gleaming in the bright sunlight tossed and 
torn at intervals, and sending from their rents and 
walls the magical blue of the ice. Ponderous neves lay 



1858.] ALONE ON THE SUMMIT. 157 

upon the mountains, apparently motionless, but sug- 
gesting motion sluggish, but indicating irresistible 
dynamic energy, which moved them slowly to their doom 
in the warmer valleys below. I thought of my position : 
it was the first time that a man had stood alone upon 
that wild peak, and were the imagination let loose amid 
the surrounding agencies, and permitted to dwell upon 
the perils which separated the climber from his kind, I 
dare say curious feelings might have been engendered. 
But I was prompt to quell all thoughts which might lessen 
my strength, or interfere with the calm application of it. 
Once indeed an accident made me shudder. While taking 
the cork from a bottle which is deposited on the top, and 
which contains the names of those who have ascended the 
mountain, my axe slipped out of my hand, and slid some 
thirty feet away from me. The thought of losing it made 
my flesh creep, for without it descent would be utterly im- 
possible. I regained it, and looked upon it with an affection 
which might be bestowed upon a living thing, for it was 
literally my staff of life under the circumstances. One 
look more over the cloud-capped mountains of Italy, and 
I then turned my back upon them, and commenced the 
descent. 

The brown crags seemed to look at me with a kind of 
friendly recognition, and, with a surer and firmer feeling than 
I possessed on ascending, I swung myself from crag to crag 
and from ledge to ledge with a velocity which surprised 
myself. I reached the summit of the Kamm, and saw 
the party which I had passed an hour and a half before, 
emerging from one of the hollows of the mountain ; 
they had escaped from the edge which now lay between 
them and me. The thought of the possible loss of my 
axe at the summit was here forcibly revived, for with- 
out it I dared not take a single step. My first care 
was to anchor it firmly in the snow, so as to enable it 



158 THE AXE SLIPS. [1858. 

to bear at times nearly the whole weight of my body. 
In some places, however, the anchor had but a loose 
hold ; the " cornice " to which I have already referred 
became granular, and the handle of the axe went through 
it up to the head, still, however, remaining loose. Some 
amount of trust had thus to be withdrawn from the 
staff and placed in the limbs. A curious mixture of care- 
lessness and anxiety sometimes fills the mind on such 
occasions. I often caught myself humming a verse of a 
frivolous song, but this was mechanical, and the sub- 
stratum of a man's feelings under such circumstances is 
real earnestness. The precipice to my left was a continual 
preacher of caution, and the slope to my right was hardly 
less impressive. I looked down the former but rarely, and 
sometimes descended for a considerable time without 
looking beyond my own footsteps. The power of a thought 
was illustrated on one of these occasions. I had descended 
with extreme slowness and caution for some time, when 
looking over the edge of the cornice I saw a row of pointed 
rocks at some distance below me. These I felt must 
receive me if I slipped over, and I thought how before 
reaching them I might so break my fall as to arrive at 
them unkilled. This thought enabled me to double my 
speed, and as long as the spiky barrier ran parallel to my 
track I held my staff in one hand, and contented myself 
with a slight pressure upon it. 

I came at length to a place where the edge was solid ice, 
which rose to the level of the cornice, the latter appearing 
as if merely stuck against it. A groove ran between the 
ice and snow, and along this groove I marched until the 
cornice became unsafe, and I had to betake myself to the 
ice. The place was really perilous, but, encouraging 
myself by the reflection that it would not last long, I care- 
fully and deliberately hewed steps, causing them to dip a 
little inward, so as to afford a purchase for the heel of mv 






1858.] ACCIDENT ON THE KAMM. 159 

boot, never forsaking one till the next was ready, and never 
wielding my hatchet until my balance was secured. I was 
soon at the bottom of the Kamm, fairly out of danger, and 
full of glad vigour I bore swiftly down upon the party in 
advance of me. It was an easy task to me to fuse myself 
amongst them as* if I had been an old acquaintance, and 
we joyfully slid, galloped, and rolled together down the 
residue of the mountain. 

The only exception was the young gentleman in 
Lauener's care. A day or two previously he had, I believe, 
injured himself in crossing the Gemmi, and long before he 
reached the summit of Monte Rosa his knee swelled, and 
he walked with great difficulty. But he persisted in 
ascending, and Lauener, seeing his great courage, thought 
it a pity to leave him behind. I have stated that a 
portion of the Kamm was solid ice. On descending this, 
Mr. F.'s footing gave way, and he slipped forward. 
Lauener was forced to accompany him, for the place was 
too steep and slippery to permit of their motion being 
checked. Both were on the point of going over the 
Lyskamm side of the mountain, where they would have 
indubitably been dashed to pieces. " There was no escape 
there," said Lauener, in describing the incident to me sub- 
sequently, " but I saw a possible rescue at the other side, 
so I sprang to the right, forcibly swinging my companion 
round ; but in doing so, the baton tripped me up ; we 
both fell, and rolled rapidly over each other down the 
incline. I knew that some precipices were in advance of 
us, over which we should have gone, so, releasing myself 
from my companion, I threw myself in front of him, 
stopped myself with my axe, and thus placed a barrier before 
him." After some vain efforts at sliding down the slopes 
on a baton, in which practice I was fairly beaten by some 
of my new friends, I attached myself to the invalid, and 
walked with him and Lauener homewards. Had I gone 



160 DANGER OF CLIMBING ALONE. [1858. 

forward witli the foremost of the party, I should have 
completed the expedition to the summit and back in a 
little better than nine hours. 

I think it right to say one earnest word in con- 
nexion with this ascent ; and the more so as I believe a 
notion is growing prevalent that half -what is said and 
written about the dangers of the Alps is mere humbug. 
No doubt exaggeration is not rare, but I would emphatically 
warn my readers against acting upon the supposition that 
it is general. The dangers of Mont Blanc, Monte Bosa, 
and other mountains, are real, and, if not properly pro- 
vided against, may be terrible. I have been much accus- 
tomed to be alone upon the glaciers, but sometimes, even 
when a guide was in front of me, I have felt an extreme 
longing to have a second one behind me. Less than two 
good ones I think an arduous climber ought not to have ; 
and if climbing without guides were to become habitual, 
deplorable consequences would assuredly sooner or later 
ensue. 



(23.) 

The 18th of August I spent upon the Furgge glacier at 
the base of Mont Cervin, and what it taught me shall be 
stated in another place. The evening of this day was 
signalised by the pleasant acquaintances which it gave 
me. It was my intention to cross the Weissthor on the 
morning of the 19th, but thunder, lightning, and heavy 
rain opposed the project, and with two friends I descended, 
amid pitiless rain, to Zermatt. Next day I walked by 
way of Stalden to Saas, where I made the acquaintance of 
Herr Imseng, the Cure, and on the 21st ascended to the 
Distel Alp. Near to this place the Allalein glacier pushes 
its huge terminus right across the valley and dams up the 



1858.] ASCENT OF A BOULDER 1G1 

streams descending from the mountains higher up, thus 
giving birth to a dismal lake. At one end of this stands 
the Mattmark hotel, which was to be my headquarters for 
a few days. 

I reached the place in good company. Near to the 
hotel are two magnificent boulders of green serpentine, 
which have been lodged there by one of the lateral 
glaciers ; and two of the ladies desiring to ascend one of 
these rocks, a friend and myself helped them to the top. 
The thing was accomplished in a very spirited way. In- 
deed the general contrast, in regard to energy, between 
the maidens of the British Isles and those of the Continent 
and of America is extraordinary. Surely those who talk 
of this country being in its old age overlook the physical 
vigour of its sons and daughters. They are strong, but 
from a combination of the greatest forces we may obtain 
a small resultant, because the forces may act in opposite 
directions and partly neutralize each other. Herein, in 
fact, lies Britain's weakness ; it is strength ill-directed ; 
and is indicative rather of the perversity of young blood 
than of the precision of mature years. 

Immediately after this achievement I was forsaken by 
my friends, and remained the only visitor in the hotel. 
A dense gray cloud gradually filled the entire atmosphere, 
from which the rain at length began to gush in torrents. 
The scene from the windows of the hotel was of the 
most dismal character; the rain also came through the 
roof, and dripped from the ceiling to the floor. I en- 
deavoured to make a fire, but the air would not let 
the smoke of the pine-logs ascend, and the biting of 
the hydrocarbons was excruciating to the eyes. On the 
whole, the cold was preferable to the smoke. During the 
night the rain changed to snow, and on the morning of 
the 22nd all the mountains were thickly covered. The 
gray delta through which a river of many arms ran 

M 



162 DISMAL QUARTEKS. [1858: 

into the Mattmark See was hidden ; against some of the 
windows of the salle d manger the snow was also piled, 
obscuring more than half their light. I had sent my guide 
to Visp, and two women and myself were the only occu- 
pants of the place. It was extremely desolate I felt, more- 
over, the chill of Monte Rosa in my throat, and the 
conditions were not favourable to the cure of a cold. 

On the 23rd the Allalein glacier was unfit for work ; 
I therefore ascended to the summit of the Monte Moro, 
and found the Valaisian side of the pass in clear sunshine, 
while impenetrable fog met us on the Italian side. I 
examined the colour of the freshly fallen snow ; it was 
not an ordinary blue, and was even more transparent than 
the blue of the firmament. When the snow was broken 
the light flashed forth ; when the staff was dug into the 
snow and withdrawn, the blue gleam appeared ; when the 
staff lay in a hole, although there might be a sufficient 
space all round it, the coloured light refused to show 
itself. 

My cough kept me awake on the night of the 23rd, and 
my cold was worse next day. I went upon the Allalein 
glacier, but found myself by no means so sure a climber 
as usual. The best guides find that their powers vary ; they 
are not equally competent on all days. I have heard a cele- 
brated Chamouni guide assert that a man's moralew different 
on different days. The morale in my case had a physical 
basis, and it probably has so in all. The Allalein gla- 
cier, as I have said, crosses the valley and abuts against 
the opposite mountain ; here it is forced to turn aside, 
and in consequence of the thrust and bending it is 
crumpled and crevassed. The wall of the Mattmark See is 
a fine glacier section : looked at from a distance, the ridges 
and fissures appear arranged like a fan. The structure of 
the crumpled ice varies from the vertical to the horizontal, 
and the ridges are sometimes split along the planes of 



1858.] THE VAULT OF THE ALLALEIN. 163 

structure. The aspect of this portion of the glacier from 
some of the adjacent heights is exceedingly interesting. 

On the morning of the 25th I had two hours' clamber- 
ing over the mountains before breakfast, and traced the 
action of ancient glaciers to a great height. The valley 
of Saas in this respect rivals that of Hasli ; the flutings 
and polishings being on the grandest scale. After break- 
fast I went to the end of the Allalein glacier, where the 
Saas Visp river rushes from it : the vault was exceedingly 
tine, being composed of concentric arches of clear blue ice. 
I spent several hours here examining the intimate struc- 
ture of the ice, and found the vacuum disks which I shall 
describe at another place, of the greatest service to me. 
As at Rosenlaui and elsewhere, they here taught me that 
the glacier was composed of an aggregate of small frag- 
ments, each of which had a definite plane of crystallization. 
Where the ice was partially weathered the surfaces of 
division between the fragments could be traced through 
the coherent mass, but on crossing these surfaces the direc- 
tion of the vacuum disks changed, indicating a similar 
change of the planes of crystallization. The blue veins 
of the glacier went through its component fragments irre- 
spective of these planes. Sometimes the vacuum disks 
were parallel to the veins, sometimes across them, some- 
times oblique to them. 

Several fine masses of ice had fallen from the arch upon 
its floor, and these were disintegrated to the core. A 
kick, or a stroke of an axe, sufficed to shake masses almost 
a cubic yard in size into fragments varying not much on 
either side of a cubic inch. The veining was finely pre- 
served on the concentric arches of the vault, and some of 
them apparently exhibited its abolition, or at least confu- 
sion, -and fresh development by new conditions of pressure. 
The river being deep and turbulent this day, to reach its 
opposite side I had to climb the glacier and cross over 

M 2 



164 AVALANCHE AT SAAS. [1858. 

the crown of its highest arch; this enabled me to get 
quite in front of the vault, to enter it, and closely inspect 
those portions where the structure appeared to change. I 
afterwards ascended the steep moraine which lies between 
the Allaleiii and the smaller glacier to the left of it, 
passing to the latter at intervals to examine its struc- 
ture. I was at length stopped by the dislocated ice ; and 
from the heights I could count a system of seven dirt- 
bands, formed by the undulations on the surface of the 
glacier. On my return to the hotel I found there a number 
of well-known Alpine men who intended to cross the 
Adler pass on the following day. Herr Imseng was there : 
he came to me full of enthusiasm, and asked me whether 
I would join him in an ascent of the Dom : we might im- 
mediately attack it, and he felt sure that we should succeed. 
The Dom is the highest of the Mischabel peaks, and 
is one of the grandest of the Alps. I agreed to join the 
Cure, and with this understanding we parted for the night. 
Thursday, 26th August. A wild stormy morning after 
a wild and rainy night : the Adler pass being impassable, 
the mountaineers returned, and Imseng informed me that 
the Dom must be abandoned. He gave me the statistics 
of an avalanche which had fallen in the valley some years 
before. Within the memory of man Saas had never been 
touched by an avalanche, but a tradition existed that such 
a catastrophe had once occurred. On the 14th of March, 
1848, at eight o'clock in the morning, the Cure was in his 
room, when he heard the cracking of pine-branches, and 
inferred from the sound that an avalanche was descend- 
ing upon the village. It dashed in the windows of his house 
and filled his rooms with snow ; the sound it produced 
being sufficient to mask the crashing of the timbers of an 
adjacent house. Three persons were killed. On the 3rd of 
April, 1849, heavy snow fell at Saas; the Cure waited 
until it had attained a depth of four feet, and then re- 



1858.] THE FEE GLACIER. 165 

treated to Fee. That night an avalanche descended, and 
in the line of its rush was a house in which five or six and 
twenty people had collected for safety : nineteen of them 
were killed. The Cure afterwards showed me the site of 
the house, and the direction of the avalanche. It passed 
through a pine wood ; and on expressing my surprise that 
the trees did not arrest it, he replied that the snow was 
" quite like dust," and rushed among the trees like so much 
water. To return from Fee to Saas on the day following 
he found it necessary to carry two planks. Kneeling upon 
one of them, he pushed the other forward, and transferred 
his weight to it, drawing the other after him and repeating 
the same act. The snow was like flour, and would not 
otherwise bear his weight. Seeing no prospect of fine 
weather, I descended to Saas on the afternoon of the 26th. 
I was the only guest at the hotel ; but during the evening 
I was gratified by the unexpected arrival of my friend 
Hirst, who was on his way over the Monte Moro to Italy. 
For the last five days it had been a struggle between 
the north wind and the south, each edging the other by 
turns out of its atmospheric bed, and producing copious 
precipitation ; but now the conflict was decided the north 
had prevailed, and an almost unclouded heaven overspread 
the Alps. The few white fleecy masses that remained 
were good indications of the swift inarch of the wind in 
the upper air. My friend and I resolved to have at least 
one day's excursion together, and we chose for it the 
glacier of the Fee. Ascending the mountain by a well- 
beaten path, we passed a number of " Calvaries " filled 
with tattered saints and Virgins, and soon came upon the 
rim of a flattened bowl quite clasped by the mountains. 
In its centre was the little hamlet of Fee, round which 
were fresh green pastures, and beyond it the perpetual 
ice and snow. It was exceedingly picturesque a scene 
of human beauty and industry where savagery alone 



166 SNOW, VAPOUR, AND CLOUD. [1858. 

was to be expected. The basin had been scooped by 
glaciers, and as we paused at its entrance the rounded 
and fluted rocks were beneath our feet. The Alphubel and 
the Mischabel raised their crowns to heaven in front of us ; 
the newly fallen snow clung where it could to the precipitous 
crags of the Mischabel, but on the summits it was the 
sport of the wind. Sometimes it was borne straight up- 
wards in long vertical striae ; sometimes the fibrous columns 
swayed to the right, sometimes to the left ; sometimes the 
motion on one of the summits would quite subside ; anon 
the white peak would appear suddenly to shake itself to 
dust, which it yielded freely to the wind. I could see the 
wafted snow gradually melt away, and again curdle up into 
true white cloud by precipitation ; this in its turn would 
be pulled asunder like carded wool, and reduced a second 
time to transparent vapour. 

In the middle of the ice of the Fee stands a green 
alp, not unlike the Jardin; up this we climbed, halting 
at intervals upon its grassy knolls to inspect the glacier. I 
aimed at those places ' where on a priori grounds I should 
have thought the production of the veined structure most 
likely, and reached at length the base of a wall of rock 
from the edge of which long spears of ice depended. 
Here my friend halted, while Lauener and myself climbed 
the precipice, and ascended to the summit of the alp. 
The snow was deep at many places, and our immersions 
in unseen holes very frequent. From the peak of the 
Fee Alp a most glorious view is obtained ; in point of 
grandeur it will bear comparison with any in the Alps, 
and its seclusion gives it an inexpressible charm. We 
remained for half an hour upon the warm rock, and then 
descended. It was our habit to jump from the higher 
ledges into the deep snow below them, in which we wal- 
lowed as if it were flour ; but on one of these occasions I 
lighted on a stone, and the shock produced a curious effect 



1858.] "A TERRIBLE HOLE." 167 

upon my hearing. I appeared suddenly to lose the power 
of appreciating deep sounds, while the shriller ones were 
comparatively unimpaired. After I rejoined my friend it 
required attention on my part to hear him when he spoke 
to me. This continued until I approached the end of the 
glacier, when suddenly the babblement of streams, and a 
world of sounds to which I had been before quite deaf 
burst in upon me. The deafness was probably due to a 
strain of the tympanum, such as we can produce artificially, 
and thus quench low sounds, while shrill ones are scarcely 
affected. 

I was anxious to quit Saas early next morning, but the 
Cure expressed so strong a wish to show us what he called 
a schauderhaftes Loch a terrible hole which he had him- 
self discovered, that I consented to accompany him. We 
were joined by his assistant and the priest of Fee. The 
stream from the Fee glacier has cut a deep channel through 
the rocks, and along the right-hand bank of the stream 
we ascended. It was very rough with fallen crags and 
fallen pines amid which we once or twice lost our way. 
At length we came to an aperture just sufficient to let a 
man's body through, and were informed by our conductor 
that our route lay along the little tunnel : he lay down upon 
his stomach and squeezed himself through it like a marmot. 
I followed him ; a second tunnel, in which, however, we 
could stand upright, led into a spacious cavern, formed 
by the falling together of immense slabs of rock which 
abutted against each other so as to form a roof. It was 
the very type of a robber den ; and when I remarked this, 
it was at once proposed to sing a verse from Schiller's play. 
The young priest had a powerful voice he led and 
we all chimed in. 

" Ein frohes Leben fiihren wir, 
Ein Leben voller Wonne. 
Der Wald ist unser Nachtquartier, 
Bei Sturm und Wind hanthieren wir, 
Der Mond ist unsre Sonne." 



168 SONG- OF THE ROBBEKS. [1858. 

Herr Imseng wore his black coat ; the others had taken 
theirs off, but they wore their clerical hats, black breeches 
and stockings. We formed a singular group in a singular 
place, and the echoed voices mingled strangely with the 
gusts of the wind and the rush of the river. 

Soon afterwards I parted from my friend, and descended the 
valley to Visp, where I also parted with my guide. He 
had been with me from the 22nd of July to the 29th of 
August, and did his duty entirely to my satisfaction. He 
is an excellent iceman, and is well acquainted both with the 
glaciers of the Oberland and of the Valais. He is strong 
and good-humoured, and were I to make another expedi- 
tion of the kind I don't think that I should take any guide 
in the Oberland in preference to Christian Lauener. 



(24.) 

It is a singular fact that as yet we know absolutely 
nothing of the winter temperature of any one of the high 
Alpine summits. No doubt it is a sufficient justification of 
our Alpine men, as regards their climbing, that they like it. 
This plain reason is enough ; and no man who ever 
ascended that " bad eminence " Primrose Hill, or climbed 
to Hampstead Heath for the sake of a freer horizon, can 
consistently ask a better. As regards physical science, 
however, the contributions of our mountaineers have as 
yet been nil, and hence, when we hear of the scientific 
value of their doings, it is simply amusing to the climbers 
themselves. I do not fear that I shall offend them in the 
least by my frankness in stating this. Their pleasure is 
that of overcoming acknowledged difficulties, and of wit- 
nessing natural grandeur. But I would venture to urge 
that our Alpine men will not find their pleasure lessened 
by embracing a scientific object in their doings. They 



1858.] CLIMBEKS AND SCIENCE. 169 

have the strength, the intelligence, and let them add to 
these the accuracy which physical science now demands, 
and they may contribute work of enduring value. Mr. 
Casella will gladly teach them the use of his minimum- 
thermometers ; and I trust that the next seven years 
will not pass without making us acquainted with the 
winter temperature of every mountain of note in Switzer- 
land.* 

I had thought of this subject since I first read the con- 
jectures of De Saussure on the temperature of Mont 
Blanc ; but in 1857 I met Auguste Balmat at the Jardin, 
and there learned from him that he entertained the idea 
of placing a self- registering thermometer at .the sum- 
mit of the mountain. Balmat was personally a stranger 
to me at the time, but Professor Forbes's writings had 
inspired me with a respect for him, which this un- 
prompted idea of his augmented. He had procured a 
thermometer, the graduation of which, however, he feared 
was not low enough. As an encouragement to Balmat, 
and with the view of making his laudable intentions known, 
I communicated them to the Royal Society, and obtained 
from the Council a small grant of money to purchase ther- 
mometers and to assist in the expenses of an ascent. 
I had now the thermometers in my possession ; and 
having completed my work at Zermatt and Saas, my next 
desire was to reach Chamouni and place the instruments 
on the top of Mont Blanc. I accordingly descended the 
valley of the Rhone to Martigny, crossed the Tete 
Noire, and arrived at Chamouni on the 29th of August, 
1858. 

Balmat was engaged at this time as the guide of Mr. 
Alfred Wills, who, however, kindly offered to place him 
at my disposal; and also expressed a desire to 'accom- 

* I find with pleasure that my friend Mr. John Ball is now exerting 
himself in this direction. 



170 DIFFICULTIES AT CHAMOUNI. [1858. 

pany me himself and assist me in my observations. I 
gladly accepted a proposal which gave me for com- 
panion so determined a climber and so estimable 
a man. But Chamouni was rife with difficulties. In 
1857 the Guide Chef had the good sense to give me 
considerable liberty of action. Now-his mood was entirely 
changed : he had been " molested " for giving me so much 
freedom. I wished to have a boy to carry a small instru- 
ment for me up the Mer de Glace he would not allow it ; 
I must take a guide. If I ascended Mont Blanc he de- 
clared that I must take four guides ; that, in short, I must 
in all respects conform to the rules made for ordinary 
tourists. I endeavoured to explain to him the advantages 
which Chamouni had derived from the labours of men of 
science ; it was such men who had discovered it when it 
was unknown, and it was by their writings that the atten- 
tion of the general public had been called towards it. It 
was a bad recompense, I urged, to treat a man of science 
as he was treating me. This was urged in vain ; he 
shrugged his shoulders, was very sorry, but the thing could 
not be changed. I then requested to know his superior, 
that I might apply to him ; he informed me that there 
were a President and Commission of guides at Chamouni, 
who were the proper persons to decide the question, and 
he proposed to call them together on the 31st of August, 
at seven P.M., on condition that I was to be present to state 
my own case. To this I agreed. 

I spent that day quite alone upon the Mer de Glace, 
and climbed amid a heavy snow-storm to the Cleft station 
over Trelaporte. When I reached the Montanvert I was 
wet and weary, and would have spent the night there were 
it not for my engagement with the Guide Chef. I de- 
scended amid the rain, and at the appointed hour went to 
his bureau. He met me with a polite sympathetic shrug ; 
explained to me that he had spoken to the Commission, 



1858.] THE INTENDANT MEMORIALISED. 171 

but that it could not assemble pour une chose comme ga ; that 
the rules were fixed, and I must abide by them. " Well," 
I responded, u you think you have done your duty ; it is 
now my turn to perform mine. If 110 other means are 
available I will have this transaction communicated to the 
Sardinian Government, and I don't think that it will ratify 
what you have done." The Guide Chef evidently did not 
believe a word of it. 

Previous to taking any further step I thought it right 
to see the President of the Commission of Guides, who was 
also Syndic of the commune. I called upon him on the 
morning of the 1st of September, and, assuming that he 
knew all about the transaction, spoke to him accordingly. 
He listened to me for a time, but did not seem to under- 
stand me, which I ascribed partly to my defective French 
pronunciation. I expressed a hope that he did comprehend 
me ; he said he understood my words very well, but did 
not know their purport. In fact he had not heard a single 
word about me or my request. He stated with some indigna- 
tion that, so far from its being a subject on which the 
Commission could not assemble, it was one which it was 
their especial duty to take into consideration. Our con- 
ference ended with the arrangement that I was to write 
him an official letter stating the case, which he was to for- 
ward to the Intendant of the province of Faucigny resi- 
dent at Bonneville. All this was done. 

I subsequently memorialised the Intendant himself; 
and Balmat visited him to secure his permission to accom- 
pany me. I have to record, .that from first to last the 
Intendant gave me his sympathy and support. He could 
not alter laws, but he deprecated a "judaical" inter- 
pretation of them. His final letter to myself was as 
follows : 



172 THE INTENDANT'S. RESPONSE. [1858. 

" Intendance Roy ale de la Province de Faucigny, 

" Bonneville, 11 Septembre, 1858. 
" Monsieur, 

" J'apprends avec une veritable peine les diffi- 
cultes que vous rencontrez de la part de M. le Guide Chef 
pour 1'effectuation de votre perilleuse entreprise scienti- 
fique, mais je dois vous dire aussi avec regret que ces diffi- 
cultes resident dans un reglementfait en vue de la securite 
des voyageurs, quel que puisse. etre le but de leurs ex- 
cursions. 

a Desireux neanmoins de vous etre utile, notamment en 
la circonstance, j 'invite aujourd'hui meme M. le Guide 
Chef a avoir egard a votre projet, a faire en sa faveur une 
exception au reglement ci-devant eu, tant qu'il n'y aura 
aucun danger pour votre surete et celle des personnes qui 
vous accompagneront, et enfin de se preter dans les liniites 
de ses moyens et attributions pour 1'heureux succes de 
1'expedition, dont les consequences et resultats n'interessent 
pas seulement la science, mais encore la vallee de Cha- 
mounix en particulier. 

" Agreez, Monsieur, 

" 1'assurance de ma consideration trds-distinguee. 
" Pour 1'Intendant en conge, 
" Le Secretaire, 

" DELMLISE." 

While waiting for this permission I employed myself in 
various .ways. On the 2nd of September I ascended the 
Brevent, from which Mont Blanc is seen to great advan- 
tage. From Chamouni its vast slopes are so foreshortened 
that one gets a very imperfect idea of the extent to be 
traversed to reach the summit. What, however, struck 
me most on the Brevent was the changed relation of 
the Aiguille du Dru and the Aiguille Verte. 'From Mont- 
anvert the former appears a most imposing mass, while 



1858.] THE "SEKACS" EEVISITED. 173 

the peak of the latter appears rather dwarfed behind it ; 
but from the Brevent the Aiguille du Dru is a mere 
pinnacle stuck in the breast of the grander pyramid of the 
Aiguille Verte. 

On the 4th I rose early, and, strapping on my telescope, 
ascended to the Montanvert, where I engaged a youth to 
accompany me up the glacier. The heavens were clear 
and beautiful : blue over the Aiguille du Dru, blue over 
the Jorasse and Mont Mallet, deep blue over the pinnacles 
of Charmoz, and the same splendid tint stretched grandly 
over the Col du Geant and its Aiguille. No trace of con- 
densation appeared till towards eleven o'clock, when a 
little black balloon of cloud swung itself over the Aiguilles 
Rouges. At one o'clock there were two large masses and 
a little one between them ; while higher up a white veil, 
almost too thin to be visible, spread over a part of the 
heavens. At the zenith, however, and south, north, and 
west, the blue seemed to deepen as the day advanced. I 
visited the ice-wall at the Tacul, which seemed lower 
than it was last year ; the cascade of le Geant appeared 
also far less imposing. Only in the early part of summer 
do we see the ice in its true grandeur : its edges and sur- 
faces are then sharp and clear, but afterwards its nobler 
masses shrink under the influence of sun and air. The 
semes now appeared wasted and dirty, and not the sharp 
angular ice-castles which rose so grandly when I first saw 
them. Thirteen men had crossed the Col du Geant on the 
day previous, and left an ample trace behind them. This 
I followed nearly to the summit of the fall. The con- 
dition of the glacier was totally different from that of 
the opposite side on the previous year. The ice was 
riven, burrowed, and honeycombed, but the track amid 
all was easy : a vigorous English maiden might have 
ascended the fall without much difficulty. My object now 
was to examine the structure of the fall ; but the ice was 



174 THERMOMETER AT THE JARDIN. [1858. 

not in a good condition for such an examination : it was 
too much broken. Still a definite structure was in many 
places to be traced, and some of them apparently showed 
structure and bedding at a high angle to each other, but 
I could not be certain of it. I paused at every command- 
ing point of view and examined the ice through my opera- 
glass ; but the result was inconclusive. I observed that 
the terraces which compose the fall do not front the middle 
of the glacier, but turn their foreheads rather towards its 
eastern side, and the consequence is that the protuberances 
lower down, which are the remains of these terraces, are 
highest at the same side. Standing at the base of the 
Aiguille Noire, and looking downwards where the Glacier 
des Periades pushes itself against the Geant, a series of fine 
crumples is formed on the former, cut across by crevasses, 
on the walls of which a forward and backward dipping of 
the blue veins is exhibited. Huge crumples are also 
formed by the Glacier du Geant, which are well seen from 
a point nearly opposite the lowest lateral moraine of the 
Glacier des Periades. In some cases the upper portions 
of the crumples had scaled off so as to form arches of 
ice a consequence doubtless of the pressure. 

The beauty of some Alpine skies is treacherous ; in fact 
the deepest blue often indicates an atmosphere charged 
almost to saturation with aqueous vapour. This was the 
case on the present occasion. Soon after reaching Chamouni 
in the evening, rain commenced and continued with scarcely 
any intermission until the afternoon of the 8th. I had 
given up all hopes of being able to ascend Mont Blanc ; 
and hence resolved to place the thermometers in some 
more accessible position. On the 9th accordingly, accom- 
panied by Mr. Wills, Balmat, and some other friends, I 
ascended to the summit of the Jardin, where we placed 
two thermometers : one in the ice, at a depth of three feet 
below the surface; another on a ledge of the highest 



1858.] EVENING RED. 175 

rock.* The boiling point of water at this place was 194'6 
Fahr. 

Deep snow was upon the Talefre, and the surrounding 
precipices were also heavily laden. Avalanches thundered 
incessantly from the Aiguille Verte and the other moun- 
tains. Scarcely five minutes on an average intervened 
between every two successive peals ; and after the direct 
shock of each avalanche had died away the air of the basin 
continued to be shaken by the echoes reflected from its 
bounding walls. 

The day was far spent before we had completed our 
work. All through the weather had been fine, and towards 
evening augmented to magnificence. As we descended 
the glacier from the Couvercle the sun was just disappear- 
ing, and the western heaven glowed with crimson, which 
crept gradually up the sky until finally it reached the 
zenith itself. Such intensity of colouring is exceedingly 
rare in the Alps ; and this fact, together with the known 
variations in the intensity of the firmamental blue, justify 
the conclusion that the colouring must, in a great measure, 
be due to some variable constituent of the atmosphere. If 
the air were competent to produce these magnificent effects 
they would be the rule instead of the exception. 

No sooner had the thermometers been thus disposed of 
than the weather appeared to undergo a permanent change. 
On the 10th it was perfectly fine not the slightest mist 
upon Mont Blanc; on the llth this was also the case. 
Balmat still had the old thermometer to which I have 
already referred ; it might not do to show the minimum 
temperature of the air, but it might show the temperature 
at a certain depth below the surface. I find in my own 
case that the finishing of work has a great moral value : 

* The minimum temperature of the subsequent winter, as shown by this 
thermometer, was -6 Fahr., or 38 below the freezing point. The instru- 
ment placed in the ice was broken. 



176 FINISHED WORK. [1858. 

work completed is a safe fulcrum for the performance of 
other work ; and even though in the course of our labours 
experience should show us a better means of accomplishing 
a given end, it is often far preferable to reach the end, 
even by defective means, than to swerve from our course. 
The habits which this conviction had superinduced no 
doubt influenced me when I decided on placing Balmat's 
thermometer on the summit; of Mont Blanc. 



1858.] SHADOWS OF THE AIGUILLES. 177 



SECOND ASCENT OF MONT BLANC, 1858. 



Ox the 12th of September, at 5^ A.M. the sunbeams had 
already fallen upon the mountain ; but though the sky above 
him, and over the entire range of the Aiguilles, was without 
a cloud, the atmosphere presented an appearance of tur- 
bidity resembling that produced by the dust and thin 
smoke mechanically suspended in a London atmosphere on 
a dry summer's day. At 20 minutes past 7 we quitted Cha- 
mouni, bearing with us the good wishes of a portion of its 
inhabitants. 

A lady accompanied us on horseback to the point where 
the path to the Grands Mulets deviates from that to 
the Plan des Aiguilles ; here she turned to the left, and 
we proceeded slowly upwards, through woods of pine, 
hung with fantastic lichens : escaping from the gloom 
of these, we emerged upon slopes of bosky underwood, green 
hazel, and green larch, with the red berries of the moun- 
tain-ash shining brightly between them. Through the air 
above us, like gnomons of a vast sundial, the Aiguilles cast 
their fanlike shadows, which moved round as the day ad- 
vanced. Slopes of rhododendrons with withered flowers 
next succeeded, but the colouring of the bilberry-leaves was 
scarcely less exquisite than the freshest bloom of the Alpine 
rose. For a long time we were in the cool shadow of the 
mountain, catching, at intervals, through the twigs in front 
of us, glimpses of the sun surrounded by coloured spectra. 
On one occasion a brow rose in front of me ; behind it was 
* a lustrous space of heaven, adjacent to the sun, which, how- 
ever, was Judder behind the brow ; against this space the 
twigs and weeds upon the summit of the brow shone as if 

N 



178 INTERFERENCE-SPECTRA. [1858. 

they were self-luminous, while some bits of thistle-down 
floating in the air appeared, where they crossed this portion 
of the heavens, like fragments of the sun himself. Once 
the orb appeared behind a rounded mass of snow which lay 
near the summit of the Aiguille du Midi. Looked at with 
the naked eyes, it seemed to possess a billowy motion, 
the light darting from it in dazzling curves, a sub- 
jective effect produced by the abnormal action of the 
intense light upon the eye. As the sun's disk came more 
into view, its rays however still grazing the summit of the 
mountain, interference-spectra darted from it on all sides, 
and surrounded it with a glory of richly-coloured bars. 
Mingling however with the grandeur of nature, we had 
the anger and obstinacy of man. With a view to subse- 
quent legal proceedings, the Guide Chef sent a spy after us, 
who, having satisfied himself of our delinquency, took his 
unpleasant presence from the splendid scene. 

Strange to say, though the luminous appearance of 
bodies projected against the sky adjacent to the rising sun 
is a most striking and beautiful phenomenon, it is hardly 
ever seen by either guides or travellers ; probably because 
they avoid looking towards a sky the brightness of which is 
painful to the eyes. In 1859 Auguste Balmat had never 
seen the effect ; and the only written description of it which 
we possess is one furnished by Professor Necker, in a letter 
to Sir David Brewster, which is so interesting that I. do 
not hesitate to reproduce it here : 

" I now come to the point," writes M. Necker, " which 
you particularly wished me to describe to you ; I mean the 
luminous appearance of trees, shrubs, and birds, when 
seen from the foot of a mountain a little before sunrise. 
The wish I had to see again the phenomenon before at- 
tempting to describe it made me detain this letter a few 
days, till I had a fine day to go to see it at the Mont 
Saleve ; so yesterday I went there, and studied the fact, and 



1858.] PROFESSOR NECKER'S LETTER. 179 

in elucidation of it I made a little drawing, of which I 
give you here a copy : it will, with the explanation and the 
annexed diagram (Fig. 9), impart to you, I hope, a correct 
idea of the phenomenon. You must conceive the observer 
placed at the foot of a hill interposed between him and the 
place where the sun is rising, and thus entirely in the 
shade ; the upper margin of the mountain is covered with 
woods or detached trees and shrubs, which are projected 
as dark objects on a very bright and clear sky, except at 
the very place where the sun is just going to rise, for 
there all the trees and shrubs bordering the margin are 
entirely, branches, leaves, stem and all, of a pure and 
brilliant white, appearing extremely bright and luminous, 
although projected on a most brilliant and luminous sky, 
as that part of it which surrounds the sun always is. All 
the minutest details, leaves, twigs, &c., are most delicately 
preserved, and you would fancy you saw these trees and 
forests made of the purest silver, with all the skill of the 
most expert workman. The swallows and other birds 
flying in those particular spots appear like sparks of the 
most brilliant white. Unfortunately, all these details, 
which add so much to the beauty of this splendid pheno- 
menon, cannot be represented in such small sketches. 

" Neither the hour of the day nor the angle which the 
object makes with the observer appears to have any effect ; 
for on some occasions I have seen the phenomenon take 
place at a very early hour in the morning. Yesterday it 
was 10 A.M., when I saw it as represented in Fig. 10. I 
saw it again on the same day at 5 P.M., at a different 
place of the same mountain, for which the sun was just 
setting. At one time the angle of elevation of the lighted 
white shrubs above the horizon of the spectator was about 
20, while at another place it was only 15. But the 
extent of the field of illumination is variable, according to 
the distance at which the spectator is placed from it. 

N 2 



180 



SILVER TREES AT SUNRISE. 



[1858. 



When the object behind which the sun is just going to 
rise, or has just been setting, is very near, no such effect 

takes place. In the case 
represented in Fig. 9 the 
distance was about 194 
metres, or 636 English 
feet, from the spectator in 
a direct line, the height 
above his level being 60 
metres, or 197 English 
feet, and the horizontal 
line drawn from him to 
the horizontal projection 
of these points on the 
plane of his horizon being 
160 metres, or 525 Eng- 
lish feet, as will be seen 

in the following diagram, 

~ig^ Fig. 10. 

" In this case only small shrubs and the lower half of the 
stem of a tree are illuminated white, and the horizontal 

extent of this effect 
is also compara- 
tively small ; while 
at other places when 
I was near the edge 
behind which the 
sun was going to rise no such effect took place. But on 
the contrary, when I have witnessed the phenomenon at a 
greater distance and at a greater height, as I have seen it 
other times on the same and on other mountains of the 
Alps, large tracts of forests and immense spruce-firs were 
illuminated white throughout their whole length, as I have 
attempted to represent in Fig. 11, and the corresponding 
diagram, Fig. 12. Nothing can be finer than these silver- 





Fig. 10. 



%M^%&^^$. 



1858. J 



BIEDS AS SPARKS OR STARS. 



181 



looking spruce-forests. At the same time, though at a 
distance of more than a thousand metres, a vast number of 
large swallows or swifts ": : - -: 

(Gypselus cdpinus\ which 
inhabit these high rocks, 
were seen as small bril- 
liant stars or sparks mov- 
ing rapidly in the air. 
From these facts it ap- 
pears to me obvious that 
the extent of the illumi- 
nated spots varies in a di- 
rect ratio of their distance ; 
but at the same time that 
there must be a constant 
angular space, correspond- 
ing probably to the zone, 
a few minutes of a de- 
gree wide, around the 
sun's disk, which is a limit Fi e- 1L 

to the occurrence of the appearance. This would explain 
how the real extent which it occupies on the earth's surface 
varies with the relative distance of the spot from the eye of 
the observer, and accounts also for the phenomenon being 



O 





Fig. I! 



never seen in the low country, where I have often looked for 
it in vain. Now that you are acquainted with the circum- 
stances of the fact, I have 110 doubt you will easily observe 
it in some part or other of your Scotch hills ; it may be 



182 THE LADDEK CONDEMNED. [1858. 

some long heather or furze will play the part of our 
Alpine forests, and I would advise you to try and place a 
bee-hive in the required position, and it would perfectly 
represent our swallows, sparks, and stars." 

Our porters, with one exception, reached the Pierre a 
1'Echelle as soon as ourselves ; and here having refreshed 
themselves, and the due exchange of loads having been 
made, we advanced upon the glacier, which we crossed, 
until we came nearly opposite to the base of the Grands 
Mulets. The existence of one wide crevasse, which was 
deemed impassable, had this year introduced the practice 
of assailing the rocks at their base, and climbing them to 
the cabin, an operation which Balmat wished to avoid. 
At Chamouni, therefore, he had made inquiries regarding 
the width of the chasm, and acting on his advice I had 
had a ladder constructed in two pieces, which, united toge- 
ther by iron attachments, was supposed to be of sufficient 
length to span the fissure. On reaching the latter, the 
pieces were united, and the ladder thrown across, but the 
bridge was so frail and shaky at the place of junction, and 
the chasm so deep, that Balmat pronounced the passage 
impracticable. 

The porters were all grouped beside the crevasse when 
this announcement was made, and, like hounds in search of 
the scent, the group instantly broke up, seeking in all 
directions for a means of passage. The talk was incessant 
and animating ; attention was now called in one direction, 
anon in another, the men meanwhile throwing themselves 
into the most picturesque groups and attitudes. All eyes 
at length were directed upon a fissure which was spanned 
at one point by an arch of snow, certainly under two feet 
deep at the crown. A stout rope was tied round the waist 
of one of our porters, and he was sent forward to test the 
bridge. He approached it cautiously, treading down the 
snow to give it compactness, and thus make his footing 



1858.] CROSSING CREVASSES. 183 

sure as lie advanced ; bringing regelation into play, he 
gave the mass the necessary continuity, and crossed in 
safety. The rope was subsequently stretched over the 
pont, and each of us causing his right hand to slide along it, 
followed withont accident. Soon afterwards, however, we 
met with a second and very formidable crevasse, to cross 
which we had but half of our ladder, which was applied as 
follows : The side of the fissure on which we stood was 
lower than the opposite one ; over the edge of the latter 
projected a cornice of snow, and a ledge of the same 
material jutted from the wall of the crevasse, a little below 
us. The ladder was placed from ledge to cornice, both of 
its ends being supported by snow. I could hardly believe 
that so frail a bearing could possibly support a man's 
weight ; but a porter was tied as before, and sent up the 
ladder, while we followed protected by the rope. We 
were afterwards tied together, and thus advanced in an 
orderly line to the Grands Mulets. 

The cabin was wet and disagreeable, but the sunbeams 
fell upon the brown rocks outside, and thither Mr. Wills 
and myself repaired to watch the changes of the atmo- 
sphere. I took possession of the flat summit of a prism of 
rock, where, lying upon my back, I watched the clouds 
forming, and melting, and massing themselves together, 
and tearing themselves like wool asunder in the air above. 
It was nature's language addressed to the intellect; 
these clouds were visible symbols which enabled us to 
understand what was going on in the invisible air. Here 
unseen currents met, possessing different temperatures, 
mixing their contents both of humidity and motion, pro- 
ducing a mean temperature unable to hold their moisture 
in a state of vapour. The water-particles, obeying their 
mutual attractions, closed up, and a visible cloud suddenly 
shook itself out, where a moment before we had the pure 
blue of heaven. Some of the clouds were wafted by the 



184 GOKGEOUS SUNSET. [1858. 

air towards atmospheric regions already saturated with 
moisture, and along their frontal borders new cloudlets 
ever piled themselves, while the hinder portions, invaded 
by a drier or a warmer air, were dissipated ; thus the 
cloud advanced, with gain in front and loss behind, its per- 
manence depending on the balance between them. The 
day waned, and the sunbeams began to assume the colour- 
ing due to their passage through the horizontal air. The 
glorious light, ever deepening in colour, was poured boun- 
teously over crags, and snows, and clouds, and suffused 
with gold and crimson the atmosphere itself. I had never 
seen anything grander than the sunset on that day. 
Clouds with their central portions densely black, denying 
all passage to the beams which smote them, floated 
westward, while the fiery fringes which bordered them 
were rendered doubly vivid by contrast with the adjacent 
gloom. The smaller and more attenuated clouds were 
intensely illuminated throughout. Across other inky 
masses were drawn zigzag bars of radiance which re- 
sembled streaks of lightning. The firmament between 
the clouds faded from a blood-red through orange and 
daffodil into an exquisite green, which spread like a 
sea of glory through which those .magnificent argosies 
slowly sailed. Some of the clouds were drawn in straight 
chords across the arch of heaven, these being doubtless 
the sections of layers of cloud whose horizontal dimen- 
sions were hidden from us. The cumuli around and near 
the sun himself could not be gazed upon, until, as the 
day declined, they gradually lost their effulgence and 
became tolerable to the eyes. All was calm but there 
was a wildness in the sky like that of anger, which boded 
evil passions on the part of the atmosphere. The sun 
at length sank behind the hills, but for some time after- 
wards carmine clouds swung themselves on high, and cast 
their ruddy hues upon the mountain snows. Duskier and 



1858.] STORM ON THE GRANDS MULETS. 185 

colder waxed the west, colder and sharper the breeze 
of evening upon the Grands Mulets, and as twilight 
deepened towards night, and the stars commenced to 
twinkle through the chilled air, we retired from the 
scene. 

The anticipated storm at length gave notice of its 
coming. The sea-waves, as observed by Aristotle, some- 
times reach the shore before the wind which produces them 
is felt ; and here the tempest sent out its precursors, 
which broke in detached shocks upon the cabin before the 
real storm arrived. Billows of air, in ever quicker succes- 
sion, rolled over us with a long surging sound, rising and 
falling as crest succeeded trough and trough succeeded 
crest. And as the pulses of a vibrating body, when 
their succession is quick enough, blend to a continuous 
note, so these fitful gusts linked themselves finally to a 
storm which made its own wild music among the crags. 
Grandly it swelled, carrying the imagination out of doors, 
to the clouds and darkness, to the loosened avalanches and 
whirling snow upon the mountain heads. Moored to the rock 
on two sides, the cabin stood firm, and its manifest security 
allowed the mind the undisturbed enjoyment of the atmo- 
spheric war. We were powerfully shaken, but had no 
fear of being uprooted ; and a certain grandeur of the 
heart rose responsive to the grandeur of the storm. 
Mounting higher and higher, it at length reached its 
maximum strength, from which it lowered fitfully, until 
at length, with a melancholy wail, it bade our rock fare- 
well. 

A little before half-past one we issued from the cabin. 
The night being without a moon, we carried three lanterns. 
The heavens were crowded with stars, among which, how- 
ever, angry masses of cloud here and there still wandered. 
The storm, too, had left a rear-guard behind it ; and strong 
gusts rolled down upon us at intervals, at one time, indeed, 



186 A COMET DISCOVERED. [1858. 

so violent as to cause Balmat to express doubts of our 
being able to reach the summit. With a thick handkerchief 
bound around my hat and ears I enjoyed the onset of the 
wind. Once, turning my head to the left, I saw what ap- 
peared to me to be a huge mass of stratus cloud, at a 
great distance, with the stars shining over it. In another 
instant a precipice of neve loomed upon us ; we were close 
to its base, and along its front the annual layers were sepa- 
rated from each other by broad dark bands. Through the 
gloom it appeared like a cloud, the lines of bedding giving 
to it the stratus character. 

Immediately before lying down on the previous evening 
I had opened the little window of the cabin to admit some 
air. In the sky in front of me shone a curious nodule of misty 
light with a pale train attached to it. In 1853, on the 
side of the Brocken, I had observed, without previous 
notice, a comet discovered a few days previously by a 
former fellow student, and here was another " discovery " 
of the same kind. I inspected the stranger with my 
telescope, and assured myself that it was a comet. Mr. 
Wills chanced to be outside at the time, and made the same 
observation independently. As we now advanced up the 
mountain its ominous light gleamed behind us, while high 
up in heaven to our left the planet Jupiter burned like 
a lamp of intense brightness. The Petit Plateau forms 
a kind of reservoir for the avalanches of the Dome du 
Gouter, and this year the accumulation of frozen debris 
upon it.was enormous. We could see nothing but the ice- 
blocks on which the light of the lanterns immediately fell ; 
we only knew that they had been discharged from the 
semes, and that similar masses now rose threatening to our 
right, and might at any moment leap down upon us. Bal- 
mat commanded silence, and urged us to move across the 
plateau with all possible celerity. The warning of our 
guide, the wild and rakish appearance of the sky, the spent 



1858.] DAWN ON THE GKAND PLATEAU. 187 

projectiles at our feet, and the comet with its " horrid 
hair " behind, formed a combination eminently calculated 
to excite the imagination. 

And now the sky began to brighten towards dawn, with 
that deep and cairn beauty which suggests the thought of 
adoration to the human mind. Helped by the contem- 
plation of the brightening east, which seemed to lend 
lightness to our muscles, we cheerily breasted the steep 
slope up to the Grand Plateau. The snow here was 
deep, and each of our porters took the lead in turn. 
We paused upon the Grand Plateau and had breakfast ; 
digging, while we halted, our feet deeply into the snow. 
Thence up to the corridor, by a totally different route from 
that pursued by Mr. Hirst and myself the year previously ; 
the slope was steep, but it had not a precipice for its boun- 
dary. Deep steps were necessary for a time, but when we 
reached the summit our ascent became more gentle. The 
eastern sky continued to brighten, and by its illumination 
the Grand Plateau and its bounding heights were lovely 
beyond conception. The snow was of the purest white, and 
the glacier, as it pushed itself on all sides into the basin, was 
riven by fissures filled with a coerulean light, which deep- 
ened to inky gloom as the vision descended into them. The 
edges were overhung with fretted cornices, from which 
depended long clear icicles, tapering from their abutments 
like spears of crystal. The distant fissures, across which 
the vision ranged obliquely without descending into them, 
emitted that magical firmamental shimmer which, contrasted 
with the pure white of the snow, was inexpressibly lovely. 
Near to us also grand castles of ice reared themselves, some 
erect, some overturned, with clear cut sides, striped by 
the courses of the annual snows, while high above the 
semes of the plateau rose their still grander brothers of 
the Dome du Gouter. There was a nobility in this glacier 
scene which I think I have never seen surpassed ; -a 



188 BALMAT IN DANGER [1858. 

strength of nature, and yet a tenderness, which at once 
raised and purified the soul. The gush of the direct 
sunlight could add nothing to this heavenly beauty ; in- 
deed I thought its yellow beams a profanation as they 
crept down from the humps of the Dromedary, and invaded 
more and more the solemn purity of the realm below. 

Our way lay for a time amid fine fissures with blue 
walls, until at length we reached the edge of one which 
elicited other sentiments than those of admiration. It 
must be crossed. At the opposite side was a high and 
steep bank of ice which prolonged itself downwards, and 
ended in a dependent eave of snow which quite over- 
hung the chasm, and reached to within about a yard of 
our edge of the crevasse. Balmat came forward with his 
axe, and tried to get a footing on the eave : he beat it 
gently, but the axe went through the snow, forming an 
aperture through which the darkness of the chasm was 
rendered visible. Our guide was quite free, without rope 
or any other means of security ; he beat down the snow so 
as to form a kind of stirrup, and upon this he stepped. 
The stirrup gave way, it was right over the centre of the 
chasm, but with wonderful tact and coolness he contrived 
to get sufficient purchase from the yielding mass to toss 
himself back to the side of the chasm. The rope was 
now brought forward and tied round the waist of one 
of the porters ; another step was cautiously made in the 
eave of snow, the man was helped across, and lessened 
his own weight by means of his hatchet. He gra- 
dually got footing on the face of the steep, which he 
mounted by escaliers ; and on reaching a sufficient height 
he cut two large steps in which his feet might rest 
securely. Here he laid his breast against the sloping wall, 
and another person was sent forward, who drew himself 
up by the rope which was attached to the leader. Thus 
we all passed, each of us in turn bearing the strain of his 



1858.] STOEM ON MONT BLANC. 189 

successor upon the rope; it was our last difficulty, and 
we afterwards slowly plodded through the snow of the 
corridor towards the base of the Mur de la Cote. 

Climbing zigzag, we soon reached the summit of 
the Mur, and immediately afterwards found ourselves 
in the midst of cold drifting clouds, which obscured 
everything. They dissolved for a moment and re- 
vealed to us the sunny valley of Chamouni ; but they 
soon swept down again and completely enveloped us. 
Upon the Calotte, or last slope, I felt no trace of the ex- 
haustion which I had experienced last year, but enjoyed free 
lungs and a quiet heart. The clouds now whirled wildly 
round us, and the fine snow, which was caught by 
the wind and spit bitterly against us, cut off all visible 
communication between us and the lower world. As 
we approached the summit the air thickened more and 
more, and the cold, resulting from the withdrawal of the 
sunbeams, became intense. We reached the top, how- 
ever, in good condition, and found the new snow piled up 
into a sharp ar6te, and the summit of a form quite dif- 
ferent from that of the Dos d'un Ane, which it had presented 
the previous year. Leaving Balmat to make a hole for the 
thermometer, I collected a number of batons, drove them 
into the snow, and, drawing my plaid round them, formed 
a kind of extempore tent to shelter my boiling- water 
apparatus. The covering was tightly held, but the snow 
was as fine and dry as dust, and penetrated everywhere : 
my lamp could not be secured from it, and half a box of 
matches was consumed in the effort to ignite it. At length 
it did flame up, and carried on a sputtering combustion. 
The cold of the snow-filled boiler condensing the vapour 
from the lamp gradually produced a drop, which, when 
heavy enough to detach itself from the vessel, fell upon 
the flame and put it out. It required much patience and 
the expenditure of many matches to relight it. Meanwhile 



190 THERMOMETER BURIED. [1858. 

the absence of muscular action caused the cold to affect 
our men severely. My beard and 1 whiskers were a mass 
of clotted ice. The batons were coated with ice, and even 
the stem of my thermometer, the bulb of which was in hot 
water, was covered by a frozen enamel. The clouds whirled, 
and the little snow granules hit spitefully against the skin 
wherever it was exposed. The temperature of the air was 
20 Fahr. below the freezing point. I was too intent upon 
my work to heed the cold much, but I was numbed ; one of 
my fingers had lost sensation, and my right heel was in 
pain : still I had no thought of forsaking my observation 
until Mr. Wills came to me and said that we must return 
speedily, for Balmat's hands were gelees. I did not com- 
prehend the full significance of the word ; but, looking at 
the porters, they presented such an aspect of suffering that 
I feared to detain them longer. They looked like worn 
old men, their hair and clothing white with snow, and 
their faces blue, withered, and anxious-looking. The hole 
being ready, I asked Balmat for the magnet to arrange 
the index of the thermometer : his hands seemed power- 
less. I struck my tent, deposited the instrument, and, as I 
watched the covering of it up, some of the party, among 
whom were Mr. Wills and Balmat, commenced the 
descent.* 

I followed them speedily. Midway down the Calotte 
I saw Balmat, who was about a hundred yards in ad- 
vance of me, suddenly pause and thrust his hands into 
the snow, and commence rubbing them vigorously. The 
suddenness of the act surprised me, but I had no idea 
at the time of its real significance : I soon came up to him ; 
he seemed frightened, and continued to beat and rub his 
hands, plunging them, at quick intervals, into the snow. Still 

* In August, 1859, I found the temperature of water, boiling in an 
open vessel at the summit of Mont Blanc, to be 184-95 Fahr. On that 
occasion also, though a laborious search was made for the thermometer, it 
could not be found. 



1858.] BALMAT FROSTBITTEN. 191 

I thought the thing would speedily pass away, for I had too 
much faith in the man's experience to suppose that he would 
permit himself to be seriously injured. But it did not pass 
as I hoped it would, and the terrible possibility of his losing 
his hands presented itself to me. He at length became 
exhausted by his own efforts, staggered like a drunken 
man, and fell upon the snow. Mr. Wills and myself took 
each a hand, and continued the process of beating and 
rubbing. I feared that we should injure him by our blows, 
but he continued to exclaim, " N'ayez pas peur, frappez tau- 
jours, frappez fortement ! " We did so, until Mr. Wills 
became exhausted, and a porter had to take his place. 
Meanwhile Balmat pinched and bit his fingers at inter- 
vals, to test their condition ; but there was no sensation. 
He was evidently hopeless himself; and, seeing him thus, 
produced an effect upon me that I had not experienced 
since my boyhood my heart swelled, and I could have 
wept like a child. The idea that I should be in some mea- 
sure the cause of his losing his hands was horrible to me ; 
schemes for his support rushed through my mind with the 
usual swiftness of such speculations, but no scheme could 
restore to him his lost hands. At length returning sensation 
in one hand announced itself by excruciating pain. " Je 
souffre ! " he exclaimed at intervals words which, from a 
man of his iron endurance, had a more than ordinary signifi- 
cance. But pain was better than death, and, under the 
circumstances, a sign of improvement. We resumed our 
descent, while he continued to rub his hands with snow and 
brandy, thrusting them at every few paces into the mass 
through which we marched. At Chamouni he had skilful 
medical advice, by adhering to which he escaped with the 
loss of six of his nails his hands were saved. 

I cannot close this recital without expressing my ad- 
miration of the dauntless bearing of our porters, and of 
the cheerful and efficient manner in which they did their 



192 PROOFS-VERBAL. [1858. 

duty throughout the whole expedition. Their names are 
Edouard Bellin, Joseph Favret, Michel Payot, Joseph 
Folliguet, and Alexandre Balmat. 



(26.) 

The hostility of the chief guide to the expedition was 
not diminished by the letter of the Intendant ; and he at 
once entered a proces-verlml against Balmat and his com- 
panions on their return to Chamouni. I felt that the 
power thus vested in an unlettered man to arrest the pro- 
gress of scientific observations was so anomalous, that the 
enlightened and liberal Government of Sardinia would 
never tolerate such a state of things if properly represented 
to it. The British Association met at Leeds that year, and 
to it, as a guardian of science, my thoughts turned. I 
accordingly laid the case before the Association, and ob- 
tained its support : a resolution was unanimously passed 
" that application be made to the Sardinian authorities for 
increased facilities for making scientific observations in 
the Alps." 

Considering the arduous work which Balmat had per- 
formed in former years in connexion with the glaciers, and 
especially his zeal in determining, under the direction of 
Professor Forbes, their winter motion for which, as in the 
case above recorded, he refused all personal remuneration 
I thought such services worthy of some recognition on 
the part of the Royal Society. I suggested this to the 
Council, and was met by the same cordial spirit of co- 
operation which I had previously experienced at Leeds. 
A sum of five-and-twenty guineas was at once voted for 
the purchase of a suitable testimonial ; and a committee, 
consisting of Sir Roderick Murchison, Professor Forbes, 



1858.] BRITISH ASSOCIATION. 193 

and myself, was appointed to carry the thing out. Balmat 
was consulted, and he chose a photographic apparatus, 
which, with a suitable inscription, was duly presented to 
him. 

Thus fortified, I drew up an account of what had occurred 
at Chamouni during my last visit, accompanied by a brief 
statement of the changes which seemed desirable. This 
was placed in the hands of the President of the British 
Association, to whose prompt and powerful co-operation in 
this matter every Alpine explorer who aspires to higher 
ground than ordinary is deeply indebted. The following 
letter assured me that the facility applied for by the British 
Association would be granted by the Sardinian Govern- 
ment, and that future men of science would find in the 
Alps a less embarrassed field of operations than had fallen 
to my lot in the summer of 1858. 

" 12, Hertford-street, Mayfair, W., 
" My dear Sir, "February 18th, 1859. 

" Having, as I informed you in my last note, 
communicated with the Sardinian Minister Plenipotentiary 
the day after receiving your statement relative to the 
guides at Chamouni, I have been favoured by replies from 
the Minister, of the 4th and 17th February. In the first 
the Marquis d'Azeglio assures me that he will bring the 
subject before the competent authorities at Turin, accom- 
panying the transmission 'd'une recomraandation. toute 
speciale.' In the second letter the Marquis informs me 
that ' the preparation of new regulations for the guides at 
Chamouni had for some time occupied the attention of the 
Minister of the Interior, and that these regulations will be 
in rigorous operation, in all probability, at the commence- 
'ment of the approaching summer.' The Marquis adds 
that, ' as the regulations will be based upon a principle of 
much greater liberty, he has every reason to believe that 





194 THE PKESIDENT'S LETTER. [1858. 

they will satisfy all the desires of travellers in the interests 
of science.' 

" With much pleasure at the opportunity of having been 
in any degree able to bring about the fulfilment of your 
wishes on the subject, 

" I remain, my dear Sir, 

" Faithfully yours, 
" RICHARD OWEN. 

" Pres. Brit. Association. 
" Prof. Tyndall, F.R.S." 

It ought to be stated that, previous to my arrival at 
Chamouni in 1858, an extremely cogent memorial drawn 
up by Mr. John Ball had been presented to the Marquis 
d'Azeglio by a deputation from the Alpine Club. It was 
probably this memorial which first directed the attention 
of the Sardinian Minister of the Interior to the subject. 



1859.] FIKST DEFEAT, AND FRESH ATTEMPT. 195 



WINTER EXPEDITION TO THE 
MER DE GLACE, 1859. 

(27.) 

HAVING ten days at my disposal last Christmas, I was 
anxious to employ them in making myself acquainted with 
the winter aspects and phenomena of the Mer de Glace. 
On Wednesday, the 21st of December, I accordingly took 
my place to Paris, but on arriving at Folkestone found 
the sea so tempestuous that no boat would venture out. 

The loss of a single day was more than I could afford, 
and this failure really involved the loss of two. Seeing, 
therefore, the prospect of any practical success so small, 
I returned to London, purposing to give the expedition 
up. On the following day, however, the weather lightened, 
and I started again, reaching Paris on Friday morning. 
On that day it was not possible to proceed beyond Macon, 
where, accordingly, I spent the night, and on the following 
day reached Geneva. 

Much snow had fallen ; at Paris it still cumbered the 
streets, and round about Macon it lay thick, as if a more 
than usually heavy cloud had discharged itself on that 
portion of the country. Between Macon and Eoussilloii 
it was lighter, but from the latter station onwards the 
quantity upon the ground gradually increased. 

On Christmas morning, at 8 o'clock, I left Geneva by 
}he diligence for Sallenches. The dawn was dull, but the 
jky cleared as the day advanced, and finally a dome of 
cloudless blue stretched overhead. The mountains were 
*rand ; their sunward portions of dazzling whiteness, while 
;he shaded sides, in contrast with the blue sky behind them, 
presented a ruddy, subjective tint. The brightness of the 

o 2 



196 GENEVA TO CHAMOUNI. [1859. 

day reached its maximum towards one o'clock, after which 
a milkiness slowly stole over the heavens, and increased 
in density until finally a drowsy turbidity filled the entire 
air. The distant peaks gradually blended with the white 
atmosphere above them and lost their definition. The black 
pine forests on the slopes of the mountains stood out in 
strong contrast to the snow ; and, when looked at through 
the spaces enclosed by the tree branches at either side of 
the road, they appeared of a decided indigo-blue. It was 
only when thus detached by a vista in front that the blue 
colour was well seen, the air itself between the eye and 
the distant pines being the seat of the colour. Goethe 
would have regarded it as an excellent illustration of his 
' Farbenlehre.' 

We reached Sallenches a little after 4 P.M., where I 
endeavoured to obtain a sledge to continue my journey. A 
fit one was not to be found, and a carriage was therefore 
the only resort. We started at five ; it was very dark, but 
the feeble reflex of the snow on each side of the road was 
preferred by the postilion to the light of lamps. Unlike 
the enviable ostrich, I cannot shut my eyes to danger when 
it is near : and as the carriage swayed towards the pre- 
cipitous road side, I could not fold myself up, as it was 
intended I should, but, quitting the interior and divesting 
my limbs of every encumbrance, I took my seat beside the 
driver, and kept myself in readiness for the spring, which 
in some cases appeared imminent. My companion how- 
ever was young, strong, and keen-eyed ; and though we 
often had occasion for the exercise of the quality last 
mentioned, we reached Servoz without accident. 

Here we baited, and our progress afterwards was slow 
and difficult. The snow on the road was deep and 
hummocky, and the strain upon the horses very great. 
Having crossed the Arve at the Pont-Pelissier, we both 
alighted, and I went on in advance. The air was 



1859.] DESOLATION. 197 

warm, and not a whisper disturbed its perfect repose. 
There was no moon, and the heavy clouds, which now 
quite overspread the heavens, cut off even the feeble 
light of the stars. The sound of the Arve, as it rushed 
through the deep valley to my left, came up to me 
through crags and trees with a sad murmur. Some- 
times on passing an obstacle, the sound was entirely cut 
off, and the consequent silence was solemn in the extreme. 
It was a churchyard stillness, and the tall black pines, 
which at intervals cast their superadded gloom upon the 
road, seemed like the hearse-plumes of a dead world. I 
reached a wooden hut, where a lame man offers batons, 
minerals, and eau de vie, to travellers in summer. It was 
forsaken, and half buried in the snow. I leaned against 
the door, and enjoyed for a time the sternness of the 
surrounding scene. My conveyance was far behind, and 
the intermittent tinkle of the horses' bells, which aug- 
mented instead of diminishing the sense of solitude, in- 
formed me of the progress and the pauses of the vehicle. 
At the summit of the road I halted until my companion 
reached me ; we then both remounted, and proceeded slowly 
towards Les Ouches. We passed some houses, the aspect 
of which was even more dismal than that of Nature ; their 
roofs were loaded with snow, and white buttresses were 
reared against the walls. There was no sound, no light, ' 
no voice of joy to indicate that it was the pleasant Christmas 
time. We once met the pioneer of a party of four drunken 
peasants : he came right against us, and the coachman had 
to pull up. Planting his feet in the snow and propping 
himself against the leader's shoulder, the bacchanal 
exhorted the postilion to drive on ; the latter took him 
at his word, and overturned him in the snow. After 
this we encountered no living thing. The horses seemed 
seized by a kind of torpor, and leaned listlessly against 
each other; vainly the postilion endeavoured to rouse 



198 A HOESE IN THE SNOW. [1859. 

them by word and whip ; they sometimes essayed to 
trot down the slopes, but immediately subsided to their 
former monotonous crawl. As we ascended the valley, 
the stillness of the air was broken at intervals by wild 
storm-gusts, sent down against us from Mont Blanc 
himself. These chilled me, so I quitted the carriage, 
and walked on. Not far from Chamouni, the road, for 
some distance, had been exposed to the full action of the 
wind, and the snow had practically erased it. Its left wall 
was completely covered, while a few detached stones, 
rising here and there above the surface, were the only 
indications of the presence and direction of the right-hand 
wall. I could not see the state of the surface, but I 
learned by other means that the snow had been heaped 
in oblique ridges across my path. I staggered over four 
or five of these in succession, sinking knee-deep, and 
finally found myself immersed to the waist. This made 
me pause ; I thought I must have lost the road, and vainly 
endeavoured to check myself by the positions of surround- 
ing objects. I turned back and met the carriage : it had 
stuck in one of the ridges ; one horse was down, his hind 
legs buried to the haunches, his left fore leg plunged to 
the shoulder in snow, and the right one thrown forward 
upon the surface. C'est lien la route ? demanded my com- 
panion. I went back exploring, and assured myself that 
we were over the road ; but I recommended him to release 
the horses and leave the carriage to its fate. He, however, 
succeeding in extricating the leader, and while I went on 
in advance seeking out the firmer portions of the road, he 
followed, holding his horses by their heads ; and half an 
hour's struggle of this kind brought us to Chamouni. 

It also was a little " city of the dead." There was no 
living thing in the streets, and neither sound nor light in 
the houses. The fountain made a melancholy gurgle, one or 
two loosened window-shutters creaked harshly in the wind, 



1859.] CHAMOUNI ON CHEISTMAS NIGHT. 199 

and banged against the objects which limited their oscilla- 
tions. The Hotel de 1'Union, so bright and gay in summer, 
was nailed up and forsaken ; and the cross in front of it, 
stretching its snow-laden arms into the dim air, was the type 
of desolation. We rang the bell at the Hotel Royal, but 
the bay of a watch-dog resounding through the house was 
long our only reply. The bell appeared powerless to wake 
the sleepers, and its sound mingled dismally with that of 
the wind howling through the deserted passages. The 
noise of my boot-heel, exerted long on the front door, was 
at length effective ; it was unbarred, and the physical 
heat of a good stove soon added itself to the warmth of 
the welcome with which my hostess greeted me. 

December 26th. The snow fell heavily, at frequent in- 
tervals, throughout the entire day. Dense clouds draped 
all the mountains, and there was not the least prospect 
of my being able to see across the Mer de Glace. I 
walked out alone in the dim light, and afterwards traversed 
the streets before going to bed. They were quite forsaken. 
Cold and sullen the Arve rolled under its wooden bridge, 
while the snow fell at intervals with heavy shock from the 
roofs of the houses, the partial echoes from the surfaces 
of the granules combining to render the sound loud and 
hollow. Thus were the concerns of this little hamlet 
changed and fashioned by the obliquity of the earth's axis, 
the chain of dependence which runs throughout creation, 
linking the roll of a planet alike with the interests of 
marmots and of men. 

Tuesday, 27th December. I rose at six o'clock, having 
arranged with my men to start at seven, if the weather at 
all permitted. Edonard Simond, my old assistant of 1857, 
and Joseph Tairraz were the guides of the party ; the 
porters were Edouard Balmat, Joseph Simond (fils d'Au- 
guste), Francois Eavanal, and another. They came at the 
time appointed ; it was snowing heavily, and we agreed to 



200 ASCENT OF THE MOUNTAIN. [1359. 

wait till eight o'clock and then decide. They returned at 
eight, and finding them disposed to try the ascent to the 
Montanvert, it was not my place to baulk them. Through 
the valley the work was easy, as the snow had been par- 
tially beaten down, but we soon passed the habitable limits, 
and had to break ground for ourselves. Three of my men 
had tried to reach the Montanvert by la Filia on the previous 
Thursday, but their experience of the route had been such 
as to deter them from trying it again. We now chose the 
ordinary route, breasting the slope until we reached the 
cluster of chalets, under the projecting eave of one of 
which the men halted and applied " pattens " to their 
feet. These consisted of planks about sixteen inches 
long and ten wide, which were firmly strapped to the feet. 
My first impression was that they were worse than useless, 
for though they sank less deeply than the unarmed feet, 
on being raised they carried with them a larger amount of 
snow, which, with the leverage of the leg, appeared to 
necessitate an enormous waste of force. I stated this em- 
phatically, but the men adhered to their pattens, and 
before I reached the Montanvert I had reason to commend 
their practice as preferable to my theory. I was however 
guided by the latter, and wore no pattens. The general 
depth of the snow along the track was over three feet ; the 
footmarks of the men were usually rigid enough to bear 
my weight, but in many cases I went through the crust 
which their pressure had produced, and sank suddenly 
in the mass. The snow became softer as we ascended, 
and my immersions more frequent, but the work was 
pure enjoyment, and the scene one of extreme beauty. 
The previous night's snow had descended through a per- 
fectly still atmosphere, and had loaded all the branches 
of the pines ; the long arms of the trees drooped under 
the weight, and presented at their extremities the ap- 
pearance of enormous talons turned downwards, Some 



1859.] SNOW ON THE PINES, 201 

of the smaller and thicker trees were almost entirely 
covered, and assumed grotesque and beautiful forms ; the 
upper part of one in particular resembled a huge white 
parrot with folded wings and drooping head, the slumber 
of the bird harmonizing with the torpor of surrounding 
nature. I have given a sketch of it in Fig. 13. 




Fig. 13. 

Previous to reaching the half-way spring, where the 
peasant girls offer strawberries to travellers in summer, 
we crossed two large couloirs filled with the debris of 
avalanches which had fallen the night before. Between 
these was a ridge forty or fifty yards wide on which the 
snow was very deep, the slope of the mountain also adding 
a component to the fair thickness of the snow. My 
' shoulder grazed the top of the embankment to my right as 
I crossed the ridge, and once or twice I found myself waist 
deep in a vertical shaft from which it required a consider- 



202 SOUND OF BREAKING SNOW. [1859. 

able effort to escape. Suddenly we heard a deep sound 
resembling the dull report of a distant gun, and at the same 
moment the snow above us broke across, forming a fissure 
parallel to our line of march. The layer of snow had been 
in a state of strain, which our crossing brought to a crisis : 
it gave way, but having thus relieved itself it did not 
descend. Several times during the ascent the same phe- 
nomenon occurred. Once, while engaged upon a very steep 
slope, one of the men cried out to the leader, " Arretez ! " 
Immediately in front of the latter the snow had given way, 
forming a zigzag fissure across the slope. We all paused, 
expecting to see an avalanche descend. Tairraz was in 
front ; he struck the snow with his baton to loosen it, but 
seeing it indisposed to descend he advanced cautiously 
across it, and was followed by the others. I brought up 
the rear. The steepness of the mountain side at this 
place, and the absence of any object to which one might 
cling, would have rendered a descent with the snow in the 
last degree perilous, and we all felt more at ease when a 
safe footing was secured at the further side of the incline. 
At the spring, which showed a little water, the men 
paused to have a morsel of bread. The wind had changed, 
the air was clearing, and our hopes brightening. As we 
ascended the atmosphere went through some extraordinary 
mutations. Clouds at first gathered round the Aiguille 
and Dome du Gouter, casting the lower slopes of the 
mountain into intense gloom. After a little time all this 
cleared away, and the beams of the sun striking detached 
pieces of the slopes and summits produced an extra- 
ordinary effect. The Aiguille and Dome were most sin- 
gularly illumined, and to the extreme left rose the white 
conical hump of the Dromedary, from which a long 
streamer of snow-dust was carried southward by the wind. 
The Aiguille du Dru, which had been completely mantled 
during the earlier part of the day, now threw off its cloak 



18.59.] COLOUR OF SNOW. 203 

of vapour and rose in most solemn majesty before us ; 
half of its granite cone was warmly illuminated, and 
half in shadow. The wind was high in the upper regions, 
and, catching the dry snow which rested on the asperities 
and ledges of the Aiguille, shook it out like a vast banner 
in the air. The changes of the atmosphere, and the 
grandeur which they by turns revealed and concealed, 
deprived the ascent of all weariness. We were usually 
flanked right and left by pines, but once between the 
fountain and the Montanvert we had to cross a wide un- 
sheltered portion of the mountain which was quite covered 
with the snow of recent avalanches. This was lumpy and 
far more coherent than the undisturbed snow.. We took 
advantage of this, and climbed zigzag over the avalanches 
for three-quarters of an hour, thus reaching the opposite 
pines at a point considerably higher than the path. This, 
though not the least dangerous, was the least fatiguing 
part of the ascent. 

I frequently examined the colour of the snow : though 
fresh, its blue tint was by no means so pronounced as I 
have seen it on other occasions ; still it was beautiful. The 
colour is, no doubt, due to the optical reverberations 
which occur within a fissure or cavity formed in the 
snow. The light is sent from side to side, each time 
plunging a little way into the mass ; and being ejected 
from it by reflection, it thus undergoes a sifting process, 
and finally reaches the eye as blue light. The pre- 
sence of any object which cuts off this cross-fire of the 
light destroys the colour. I made conical apertures in the 
snow, in some cases three feet deep, a foot wide at the 
mouth, and tapering down to the width of my baton. 
When the latter was placed along the axis of such a cone, 
the blue light which had previously filled the cavity disap- 
peared ; on the withdrawal of the baton it was followed 
by the light, and thus by moving the staff up and down 



204 THE MONTANVERT IN WINTER, [1859. 

its motions were followed by the alternate appearance and 
extinction of the light. I have said that the holes made 
in the snow seemed filled with a blue light, and it certainly 
appeared as if the air contained in the cavities had 
itself been coloured, and thereby rendered visible, the 
vision plunging into it as into a blue medium. Another 
fact is perhaps worth notice : snow rarely lies so smooth as 
not to present little asperities at its surface ; little ridges 
or hillocks, with little hollows between them. Such small 
hollows resemble, in some degree, the cavities which I made 
in the snow, and from them, in the present instance, a 
delicate light was sent to the eye, faintly tinted with 
the pure blue of the snow-crystals. In comparison 
with the spots thus illuminated, the little protuberances 
were gray. The portions most exposed to the light seemed 
least illuminated, and their defect in this respect made 
them appear as if a light-brown dust had been strewn over 
them. 

After five hours and a half of hard work we reached the 
Montanvert. I had often seen it with pleasure. Often, 
having spent the day alone amid the seracs of the Col du 
Geant, on turning the promontory of Trelaporte on my way 
home, the sight of the little mansion has gladdened me, and 
given me vigour to scamper down the glacier, knowing 
that pleasant faces and wholesome fare were awaiting 
me. This day, also, the sight of it was most welcome, 
despite its desolation. The wind had swept round the 
auberge, and carried away its snow-buttresses, piling the 
mass thus displaced against the adjacent sheds, to the roofs 
of which one might step from the surface of the snow. The 
floor of the little chateau in which I lodged in 1857 was 
covered with snow, and on it were the fresh footmarks 
of a little animal a marmot might have made such 
marks, had not the marmots been all asleep what the 
creature was I do not know, 



1859.] CRYSTAL CURTAIN. 205 

In the application of her own principles, Nature often 
transcends the human imagination ; her acts are bolder than 
our predictions. It is thus with the motion of glaciers; it was 
thus at the Montanvert on the day now referred to. The 
floors, even where the windows appeared well closed, were 
covered with a thin layer of fine snow ; and some of the 
mattresses in the bedrooms were coated to the depth of 
half an inch with this fine powder. Given a chink through 
which the finest dust can pass, dry snow appears com- 
petent to make its way through the same fissure. It had 
also been beaten against the windows, and clung there 
like a ribbed drapery. In one case an effect so singular 
was exhibited, that I doubted my eyes when I first saw it. 
In front of a large pane of glass, and quite detached 
from it, save at its upper edge, was a festooned curtain 
formed entirely of minute ice-crystals. It appeared to be 
as fine as muslin ; the ease of its curves and the depth 
of its folds being such as could not be excelled by the 
intentional arrangement of ordinary gauze. The frost- 
figures on some of the window-panes were also of the most 
extraordinary character : in some cases they extended 
over large spaces, and presented the appearance which we 
often observe in London ; but on other panes they oc- 
curred in detached clusters, or in single flowers, these 
grouping themselves together to form miniature bouquets 
of inimitable beauty. I placed my warm hand against 
a pane which was covered by the crystallization, and 
melted the frostwork which clung to it. I then withdrew 
my hand and looked at the film of liquid through a pocket- 
lens. The glass cooled by contact with the air, and after 
a time the film commenced to move at one of its edges ; 
atom closed with atom, and the motion ran in living lines 
through the pellicle, until finally the entire film presented 
the beauty and delicacy of an organism. The connexion 
between such objects and what we are accustomed to 



206 THE MER DE GLACE IN WINTER. [1859. 

call the feelings may not be manifest, but it is nevertheless 
true that, besides appealing to the pure intellect of man, 
these exquisite productions can also gladden his heart and 
moisten his eyes. 

The glacier excited the admiration of us all : not as in 
summer, shrunk and sullied like a spent reptile, steaming 
under the influence of the sun ; its frozen muscles were 
compact, strength and beauty were associated in its 
aspect. At some places it was pure and smooth; at 
others frozen fins arose from it, high, steep, and sharply 
crested. Down the opposite mountain side arrested streams 
set themselves erect in successive terraces, the fronts of 
which were fluted pillars of ice. There was no sound of 
water ; even the Nant Blanc, which gushes from a spring, 
and which some describe as permanent throughout the 
winter, showed no trace of existence. From the Montanvert 
to Trelaporte the Mer de Glace was all in shadow ; but the 
sunbeams pouring down the corridor of the Geant ruled 
a beam of light across the glacier at its upper portion, 
smote the base of the Aiguille du Moine, and flooded 
the mountain with glory to its crest. At the opposite side 
of the valley was the Aiguille du Dru, with a banneret 
of snow streaming from its mighty cone. The Grande 
Jorasse, and the range of summits between it and the 
Aiguille du Geant, were all in view, and the Charmoz 
raised its precipitous cliffs to the right, and pierced with 
its splinter-like pinnacles the clear cold air. As the night 
drew on, the mountains seemed to close in upon us ; and 
on looking out before retiring to rest, a scene so solemn 
had never before presented itself to my eyes or affected 
my imagination. 

My men occupied the afternoon of the day of our 
arrival in making a preliminary essay upon the glacier 
while I prepared my instruments. To the person whom 
I intended to fix my stations, three others were at- 



1859.] THE FIEST NIGHT. 207 

tached by sound ropes of considerable length. Hidden 
crevasses we knew were to be encountered, and we had 
made due preparation for them. Throughout the afternoon 
the weather remained fine, and at night the .stars shone 
out, but still with a feeble lustre. I could notice a tur- 
bidity gathering in the air over the range of the Brevent, 
which seemed disposed to extend itself towards us. At 
night I placed a chair in the middle of the snow, at some 
distance from the house, and laid on it a registering 
thermometer. A bountiful fire of pine logs was made in 
the salle d manger ; a mattress was placed with its foot 
towards the fire, its middle line bisecting the right angle 
in which the fireplace stood ; this being found by experi- 
ment to be the position in which the draughts from the door 
and from the windows most effectually neutralized each 
other. In this region of calms I lay down, and covering 
myself with blankets and duvets, listened to the crack- 
ling of the logs, and watched their ruddy flicker upon the 
walls, until I fell asleep. 

The wind rose during the night, and shook the windows : 
one pane in particular seemed set in unison to the gusts, 
and responded to them by a loud and melodious vibration. 
I rose and wedged it round with sous and penny pieces, 
and thus quenched its untimely music. 

December 28th. We were up before the dawn. 
Tairraz put my fire in order, and I then rose. The tem- 
perature of the room at a distance of eight feet from 
the fire was two degrees of Centigrade below zero ; the 
lowest temperature outside was eleven degrees of Centi- 
grade below zero, not at all an excessive cold. The 
clouds indeed had, during the night, thrown vast diaphragms 
across the sky, and thus prevented the escape of the earth's 
heat into space. 

While my assistants were preparing breakfast I had 
time to inspect the glacier and its bounding heights. On 



208 A "ROSE OF DAWN." [1859. 

looking up the Mer de Glace, the Grande Jorasse meets 
the view, rising in steep outline from the wall of cliffs 
which terminates the Glacier de Lechaud. Behind this 
steep ascending ridge, which is shown on the frontis- 
piece, and upon it, a series of clouds had ranged them- 
selves, stretching lightly along the ridge at some places, 
and at others collecting into ganglia. A string of 
rosettes was thus formed which were connected together 
by gauzy filaments. The portion of the heavens behind 
the Bridge was near the domain of the rising sun, and 
when he cleared the horizon his red light fell upon 
the clouds, and ignited them to ruddy flames. Some 
of the lighter clouds doubled round the summit of the 
mountain, and swathed its black crags with a vestment of 
transparent red. The adjacent sky wore a strange and 
supernatural air ; indeed there was something in the whole 
scene which baffled analysis, and the words of Tennyson 
rose to my lips as I gazed upon it : 

" God made Himself an awful rose of dawn." 

I have spoken several times of the cloud-flag which 
the wind wafted from the summit of the Aiguille du Dru. 
On the present occasion this grand banner reached ex- 
traordinary dimensions. It was brindled in some places 
as if whipped into curds by the wind ; but through these 
continuous streamers were drawn, which were bent into 
sinuosities resembling a waving flag at a mast-head. 
All this was now illuminated with the sun's red rays, 
which also fringed with fire the exposed edges and 
pinnacles both of the Aiguille du Dru and the Aiguille 
Verte. Thus rising out of the shade of the valley the 
mountains burned like a pair of torches, the flames of 
which were blown half a mile through the air. Soon after- 
wards the summits of the Aiguilles Rouges were illuminated, 
and day declared itself openly among the mountains. 



1859.] THE STAKES FIXED. 209 

But these red clouds of the morning, magnificent 
though they were, suggested thoughts which tended to 
qualify the pleasure which they gave : they did not indi- 
cate good weather. Sometimes, indeed, they had to fight 
with denser masses, which often prevailed, swathing the 
mountains in deep neutral tint, but which, again yielding, 
left the glory of the sunrise augmented by contrast with 
their gloom. Between eight and nine A.M. we commenced 
the setting out of our first line, one of whose termini was a 
point about a hundred yards higher up than the Montanvert 
hotel ; a withered pine on the opposite mountain side mark- 
ing the other terminus. The stakes made use of were four 
feet long. With the selfsame baton which I had employed 
upon the Mer de Glace in 1857, and which Simond had pre- 
served, the worthy fellow now took up the line. At some 
places the snow was very deep, but its lower portions were 
sufficiently compact to allow of a stake being firmly fixed in 
it. At those places where the wind had removed the snow 
or rendered it thin, the ice was pierced with an auger 
and the stake driven into it. The greatest caution was 
of course necessary on the part of the men ; they were in 
the midst of concealed crevasses, and sounding was essen- 
tial at every step. By degrees they withdrew from me, 
and approached the eastern boundary of the glacier, where 
the ice was greatly dislocated, and the labour of wading 
through the snow enormous. Long detours were some- 
times necessary to reach a required point ; but they were all 
accomplished, and we at length succeeded in fixing eleven 
stakes along this line, the most distant of which was within 
about eighty yards of the opposite side of the glacier. 

The men returned, and I consulted them as to the pos- 
sibility of getting a line across at the Fonts ; but this was 
' judged to be impossible in the time. We thought, however, 
that a second line might be staked out at some distance 
below the Montanvert. I took the theodolite down the 



210 STORM ON THE GLACIER. [1859. 

mountain -slope, wading at times breast-deep in snow, and 
having selected a line, the men tied themselves together 
as before, and commenced the staking out. The work 
was slowly but steadily and steadfastly done. The air 
darkened ; angry clouds gathered around the moun- 
tains, and at times the glacier was swept by wild 
squalls. The men were sometimes hidden from me by 
the clouds of snow which enveloped them, but between 
those intermittent gusts there were intervals of repose, 
which enabled us to prosecute our work. This line 
was more difficult than the first one; the glacier was 
broken into sharp-edged chasms ; the ridges to be climbed 
were steep, and the snow which filled the depressions pro- 
found. The oblique arrangement of the crevasses also 
magnified the labour by increasing the circuits. I saw the 
leader of the party often shoulder-deep in snow, treading the 
soft mass as a swimmer walks in water, and I felt a wish 
to be at his side to cheer him and to share his toil. Each 
man there, however, knew my willingness to do this if 
occasion required it, and wrought contented. At length 
the last stake being fixed, the faces of the men were 
turned homeward. The evening became wilder, and the 
storm rose at times to a hurricane. On the more level 
portions of the glacier the snow lay deep and unshel- 
tered ; among its frozen waves and upon its more dislo- 
cated portions it had been partially engulfed, and the 
residue was more or less in shelter. Over the former 
spaces dense clouds of snow rose, whirling in the air and 
cutting off all view of the glacier. The whole length of 
the Mer de Glace was thus divided into clear and cloudy 
segments, and presented an aspect of wild and wonderful 
turmoil. A large pine stood near me, with its lowest 
branch spread out upon the surface of the snow ; on t his 
branch I seated myself, and, sheltered by the trunk, waited 
until I saw my men in safety. The wind caught the 



1859.] HEAVY SNOW. 211 

branches of the trees, shook down their loads of snow, 
and tossed it wildly in the air. Every mountain gave 
a quota to the storm. The scene was one of most im- 
pressive grandeur, and the moan of the adjacent pines 
chimed in noble harmony with the picture which addressed 
the eyes. 

At length we all found ourselves in safety within 
doors. The windows shook violently. The tempest was 
however intermittent throughout, as if at each effort it 
had exhausted itself, and required time to recover its 
strength. As I heard its heralding roar in the gullies of 
the mountains, and its subsequent onset against our habi- 
tation, I thought wistfully of my stations, not knowing 
whether they would be able to retain their positions in 
the face of such a blast. That night however, as if the 
storm had sung our lullaby, we all slept profoundly, 
having arranged to commence our measurements as early 
as light permitted on the following day. 

Thursday, 29th December. "Snow, heavy snow: it must 
have descended throughout the entire night ; the quantity 
freshly fallen is so great ; the atmosphere at seven o'clock 
is thick with the descending flakes." At eight o'clock it 
cleared up a little, and I proceeded to my station, while 
the men advanced upon the glacier ; but I had scarcely 
fixed my theodolite when the storm recommenced. I 
had a man to clear away the snow and otherwise assist me ; 
he procured an old door from the hotel, and by rearing 
it upon its end sheltered the object-glass of the in- 
strument. Added to the flakes descending from the clouds 
was the spitting snow- dust raised by the wind, which 
for a time so blinded me that I was unable to see the 
glacier. The measurement of the first stake was very 
tedious, but practice afterwards enabled me to take advan- 
tage of the brief lulls and periods of partial clearness 
with which the storm was interfused, 

P 2 



212 A MAN IN A CREVASSE. [1859. 

At nine o'clock my telescope happened to be directed 
upon the men as they struggled through the snow ; all 
evidence of the deep track which they had formed yester- 
day having been swept away. I saw the leader sink 
and suddenly disappear. He had stood over a concealed 
fissure, the roof of which had given way and he had dropped 
in. I observed a rapid movement on the part of the re- 
maining three men : they grouped themselves beside the 
fissure, and in a moment the missing man was drawn from 
between its jaws. His disappearance and reappearance 
were both extraordinary. We had, as I have stated, pro- 
vided for contingencies of this kind, and the man's rescue 
was almost immediate. 

My attendant brought two poles from the hotel which 
we thrust obliquely into the snow, causing the free ends 
to cross each other ; over these a blanket was thrown, be- 
hind which I sheltered myself from the storm as the men 
proceeded from stake to stake. At 9.30 the storm was so 
thick that I was unable to see the men at the stake 
which they had reached at the time ; the flakes sped 
wildly in their oblique course across the field of the tele- 
scope. Some time afterwards the air became quite still, 
and the snow underwent a wonderful change. Frozen 
flowers similar to those I had observed on Monte Rosa 
fell in myriads. For a long time the flakes were wholly 
composed of these exquisite blossoms entangled together. 
On the surface of my woollen dress they were soft as 
down ; the snow itself on which they fell seemed covered 
by a layer of down ; while my coat was completely 
spangled with six-rayed stars. And thus prodigal Nature 
rained down beauty, and had done so here for ages unseen 
by man. And yet some flatter themselves with the idea that 
this world was planned with strict reference to human use ; 
that the lilies of the field exist simply to appeal to the sense 
of the beautiful in man. True, this result is secured, but it 



18.59.] SIX-RAYED CRYSTALS. 213 

is one of a thousand all equally important in the eyes of 
Nature. Whence those frozen blossoms ? Why for aeons 
wasted ? The question reminds one of the poet's answer 
when asked whence was the Rhodora : 

" Why wert thou there, rival of the rose ? 

I never thought to ask, I never knew ; 
But in my simple ignorance suppose 
The selfsame power that brought me there brought you ! " * 

I sketched some of the crystals, but, instead of repro- 
ducing these sketches, which were rough and hasty, I have 
annexed two of the forms drawn with so much skill and 
patience by Mr. Glaisher. 

We completed the measurement of the first line before 
eleven o'clock, and I felt great satisfaction in the thought 
that I possessed something of which the weather could not 
deprive me. As I closed my note-book and shifted the 
instrument to the second station, I felt that my expedi- 
tion was already a success. 

At a quarter past eleven I had my theodolite again fixed, 
and ranging the telescope along the line of pickets, I saw 
them all standing. Crossing the ice wilderness, and sug- 
gesting the operation of intelligence amid that scene of 
desolation, their appearance was pleasant to me. Just 
before I commenced, a solitary jay perched upon the sum- 
mit of an adjacent pine and watched me. The air was 
still at the time, and the snow fell heavily. The flowers 
moreover were magnificent, varying from about the twen- 
tieth of an inch to two lines in diameter, while, falling 
through the quiet air, their forms were perfect. Adjacent 
to my theodolite was a stump of pine, from which I had 
the snow removed, in order to have something to kick my 
toes against when they became cold ; and on the stump 
was placed a blanket to be used as a screen in case of need. 
While I remained at the station a layer of snow an inch 
* Emerson. 




Fig. 14. 




Fig. 15. 



1859.] SOUND THROUGH THE SNOWSTORM. 215 

thick fell upon this blanket, the whole layer being com- 
posed of these exquisite flowers. The atmosphere also was 
filled with them. From the clouds to the earth Nature was 
busy marshalling her atoms, and putting to shame by the 
beauty of her structures the comparative barbarities of Art. 
My men at length reached the first station, and the 
measurement commenced. The storm drifted up the val- 
ley, thickening all the air as it approached. Denser and 
denser the flakes fell ; but still, with care and tact I was 
able to follow my party to a distance of 800 yards. I had 
not thought it possible to see so far through so dense a storm. 
At this distance also my voice could be heard, and my 
instructions understood ; for once, as the man who took 
up the line stood behind his baton and prevented its pro- 
jection against the white snow, I called out to him to stand 
aside, and he promptly did so. Throughout the entire 
measurement the ' snow never ceased falling, and some of 
the illusions which it produced were extremely singular. 
The distant boundary of the glacier appeared to rise to an 
extraordinary height, and the men wading through the snow 
appeared as if climbing up a wall. The labour along this 
line was still greater than on the former ; on the steeper 
slopes especially the toil was great ; for here the effort of 
the leader to lift his own body added itself to that of cut- 
ting his way through the snow. His footing I could see 
often yielded, and he slid back, checking his recession, 
however, by still plunging forward ; thus, though the 
limbs were incessantly exerted, it was, for a time, a mere 
motion of vibration without any sensible translation. At 
the last stake the men shouted, " Nous avons finis ! " and 
I distinctly heard them through the falling snow. By this 
time I was quite covered with the crystals which clung to 
my wrapper. They also formed a heap upon my theodo- 
lite, rising over the spirit-levels and embracing the lower 
portion of the vertical arc. The work was done ; I struck 



216 SWIFT DESCENT. [1859. 

my theodolite and ascended to the hotel ; the greatest 
depth of snow through which I waded reaching, when I 
stood erect, to within three inches of my breast. 

The men returned ; dinner was prepared and consumed ; 
the disorder which we had created made good ; the rooms 
were swept, the mattresses replaced, and the shutters fast- 
ened, where this was possible. We locked up the house, 
and with light hearts and lithe limbs commenced the de- 
scent. My aim now was to reach the source of the Arvei- 
ron, to examine the water and inspect the vault. With 
this view we went straight down the mountain. The inclina- 
tions were often extremely steep, and down these we swept 
with an avalanche-velocity ; indeed usually accompanied 
by an avalanche of our own creation. On one occasion 
Balmat was for a moment overwhelmed by the descending 
mass : the guides were startled, but he emerged instantly. 
Tairraz followed him, and I followed Tairraz, all of us roll- 
ing in the snow at the bottom of the slope as if it were so 
much flour. My practice on the Finsteraarhom rendered 
me at home here. One of the porters could by no means 
be induced to try this flying mode of descent. Simond 
carried my theodolite box, tied upon a crotchet on his 
back ; and once, while shooting down a slope, he incau- 
tiously allowed a foot to get entangled ; his momentum 
rolled him over and over down the incline, the theodolite 
emerging periodically from the snow during his successive 
revolutions. A succession of qlissades brought us with 

*/ O 

amazing celerity to the bottom of the mountain, whence 
we picked our way amid the covered boulders and over the 
concealed arms of the stream to the source of the Arveiron. 
The quantity of water issuing from the vault was consider- 
able, and its character that of true glacier water. It was turbid 
with suspended matter, though not so turbid as in summer ; 
but the difference in force and quantity would, I think, be 
sufficient to account for the greater summer turbidity. This 



1859.] VAULT OF THE ARVEIRON. 217 

character of the water could only be due to the grinding mo- 
tion of the glacier upon its bed ; a motion which seems not 
to be suspended even in the depth of winter. The tempe- 
rature of the water was the tenth of a degree Centigrade 
above zero ; that of the ice was half a degree below zero : 
this was also the temperature of the air, while that of the 
snow, which in some places covered the ice-blocks, was 
a degree and a quarter below zero. 

The entrance to the vault was formed by an arch of ice 
which had detached itself from the general mass of the 
glacier behind : between them was a space through which 
we could look to the sky above. Beyond this the cave nar- 
rowed, and we found ourselves steeped in the blue light of 
the ice. The roof of the inner arch was perforated at one 
place by a shaft about a yard wide, which ran vertically to 
the surface of the glacier. Water had run down the sides 
of this shaft, and, being re-frozen below, formed a compo- 
site pillar of icicles at least twenty feet high and a yard 
thick, stretching quite from roof to floor. They were all 
united to a common surface at one side, but at the 
other they formed a series of flutiiigs of exceeding beauty. 
This group of columns was bent at its base as if it had 
yielded to the forward motion of the glacier, or to the 
weight of the arch overhead. Passing over a number of 
large ice-blocks which partially filled the interior of the 
vault, we reached its extremity, and here found a sloping 
passage with a perfect arch of crystal overhead, and lead- 
ing by a steep gradient to the air above. This singular gal- 
lery was about seventy feet long, -and was floored with 
snow. We crept up it, and from the summit descended by 
a glissade to the frontal portion of the cavern. To me this 
crystal cave, with the blue light glistening from its walls, 
presented an aspect of magical beauty. My delight, how- 
ever, was tame compared with that of my companions. 
Looking from the blue arch westwards, the heavens were 



218 MAJESTIC SCENE. [1859. 

seen filled by crimson clouds, with fiery outliers reaching 
up to the zenith. On quitting the vault I turned to 
have a last look at those noble sentinels of the Mer de 
Glace, the Aiguille du Dru, and the Aiguille Verte. The 
glacier below the mountains was in shadow, and its frozen 
precipices of a deep cold blue. From this, as from a 
basis, the mountain cones sprang steeply heavenward, 
meeting halfway down the .fiery light of the sinking sun. 
The right-hand slopes and edges of both pyramids burned 
in this light, while detached protuberant masses also caught 
the blaze, and mottled the mountains with effulgent spaces. 
A range of minor peaks ran slanting downwards from 
the summit of the Aiguille Verte ; some of these were 
covered with snow, and shone as if illuminated with 
the deep crimson of a strontian flame. I was absolutely 
struck dumb by the extraordinary majesty of this scene, 
and watched it silently till the red light faded from the 
highest summits. Thus ended my winter expedition to 
the Mer de Glace. 

Next morning, starting at three o'clock, I was driven 
by my two guides in an open sledge to Sallenches. The 
rain was pitiless and the road abominable. The distance, 
I believe, is only six leagues, but it took us five hours to 
accomplish it. The leading mule was beyond the reach of 
Simond's whip, and proved a mere obstructive ; during 
part of the way it was unloosed, tied to the sledge, and 
dragged after it. Simond afterwards mounted the hind- 
most beast and brought his whip to bear upon the leader ; 
the jerking he endured for an hour and a half seemed 
almost sufficient to dislocate his bones. We reached 
Sallenches half an hour late, but the diligence was behind 
its time by this exact interval. We met it on the Pont St. 
Martin, and I transferred myself from the sledge to the 
interior. This was the morning of the 30th of December, 
and on the evening of the 1st of January I was in London. 



1859.] MY ASSISTANTS. . 219 

I cannot finish this recital without saying one word about 
my men. Their behaviour was admirable throughout. The 
labour was enormous, but it was manfully and cheerfully 
done. I know Simond well ; he is intelligent, truthful, 
and affectionate, and there is no guide of my acquaint- 
ance for whom I have a stronger regard. Joseph Tairraz 
is an extremely intelligent and able guide, and on this 
trying occasion proved himself worthy of my highest praise 
and commendation. Their two companions upon the gla- 
cier, Edouard Balmat (le Petit Balmat) and Joseph Si- 
mond (fils d'Auguste), acquitted themselves admirably ; 
and it also gives me pleasure to bear testimony to the will- 
ing and efficient service of Franpois Ravanal, who attended 
upon me during the observations. 



PART II. 

CHIEFLY SCIENTIFIC, 



Aber im stillen Gemach entwirft bedeutende Zirkel 

Sinnend der Weise, beschleicht forschend den schaffenden Geist, 

Priift der Stoffe Gewalt, der Magnete Hassen und Lieben, 

Folgt durch die Liifte dem Klang, folgt durch den Aether dem Strahl, 

Sucht das^vertraute Gesetz in des Zufalls grausenden Wundern, 
Sucht den ruhenden Pol in der Erscheinungen Flucht. 

SCHILLER. 



THEORIES OF LIGHT. 223 



ON LIGHT AND HEAT. 



WHAT is Light ? The ancients supposed it to be some- 
thing emitted by the eyes, and for ages no notion was 
entertained that it required time to pass through space. 
In the year 1676 Homer first proved that the light from 
Jupiter's satellites required a certain time to cross the 
earth's orbit. Bradley afterwards found that, owing to 
the velocity with which the earth flies through space, 
the rays of the stars are slightly inclined, just as rain- 
drops which descend vertically appear to meet us when 
we move swiftly through the shower. In Kew Gardens 
there is a sun-dial commemorative of this discovery, which 
is called the aberration of light. Knowing the velocity of 
the earth, and the inclination of the stellar rays, Bradley 
was able to calculate the velocity of light ; and his result 
agrees closely with that of Romer. Celestial distances 
were here involved, but a few years ago M. Fizeau, by 
an extremely ingenious contrivance, determined the time 
required by light to pass over a distance of about 9000 
yards ; and his experiment is quite in accordance with the 
results of his predecessors. 

But what is it which thus moves ? Some, and among 
the number Newton, imagined light to consist of particles 
darted out from luminous bodies. This is the so-called 
Emission-Theory, which was held by some of the greatest 
men : Laplace, for example, accepted it ; and M. Biot 
has developed it with a lucidity and power peculiar to 
himself. It was first opposed by the astronomer Huyghens, 
and afterwards by Euler, both of whom supposed light to 
be a kind of undulatory motion ; but they were borne 



224 NATURE OF SOUND. 

down by their great antagonists, and the emission-theory 
held its ground until the commencement of the present 
century, when Thomas Young, Professor of Natural Phi- 
losophy in the Royal Institution, reversed the scientific 
creed by placing the Theory of Undulation on firm founda- 
tions. He was followed by a young Frenchman of extra- 
ordinary genius, who, by the force of his logic and the 
conclusiveness of his experiments, left the Wave-Theory 
without a competitor. The name of this young French- 
man was Augustin Fresnel. 

Since his time some of the ablest minds in Europe have 
been applied to the investigation of this subject ; and thus 
a mastery, almost miraculous, has been attained over the 
grandest and most subtle of natural phenomena. True 
knowledge is always fruitful, and a clear conception 
regarding any one natural agent leads infallibly to better 
notions regarding others. Thus it is that our knowledge 
of light has corrected and expanded our knowledge of 
heat, while the latter, in its turn, will assuredly lead us to 
clearer conceptions regarding the other forces of Nature. 

I think it will not be a useless labour if I here endeavour 
to state, in a Simple manner, our present views of light 
and heat. Such knowledge is essential to the explanation 
of many of the phenomena referred to in the foregoing 
pages ; and even to the full comprehension of the origin 
of the glaciers themselves. A few remarks on the nature 
of sound will form a fit introduction. 

It is known that sound is conveyed to our organs of 
hearing by the air : a bell struck in a vacuum emits no 
sound, and even when the air is thin the sound is enfeebled. 
Hawksbee proved this by the air-pump ; De Saussure fired 
a pistol at the top of Mont Blanc, I have repeated the 
experiment myself, and found, with him, that the sound is 
feebler than at the sea level. Sound is not produced by 
anything projected through the air. The explosion of a 



CAUSE OF MUSIC. 225 

gun, for example, is sent forward by a motion of a totally 
different kind from that which animates the bullet pro- 
jected from the gun : the latter is a motion of translation; 
the former, one of vibration. To use a rough comparison, 
sound is projected through the air as a push is through a 
crowd ; it is the propagation of a wave or pulse, each par- 
ticle taking up the motion of its neighbour, and delivering 
it on to the next. These aerial waves enter the external 
ear, meet a membrane, the so-called tympanic membrane, 
which is drawn across the passage at a certain place, and 
break upon it as sea-waves do upon the shore. The mem- 
brane is shaken, its tremors are communicated to the 
auditory nerve, and transmitted by it to the brain, where 
they produce the impression to which we give the name 
of sound. 

In the tumult of a city, pulses of different kinds strike 
irregularly upon the tympanum, and we call the effect 
noise ; but when a succession of impulses reach the ear at 
regular intervals we feel the effect as music. Thus, a 
vibrating string imparts a series of shocks to the air around 
it, which are transmitted with perfect regularity to the ear, 
and produce a musical note. When we hear the song of a 
soaring lark we may be sure that the entire atmosphere 
between us and the bird is filled with pulses, or undula- 
tions, or waves, as they are often called, produced by the 
little songster's organ of voice. This organ is a vibrating 
instrument, resembling, in principle, the reed of a clarionet. 
Let us suppose that we hear the song of a lark, ele- 
vated to a height of 500 feet in the air. Before this is 
possible, the bird must have agitated a sphere of air 1000 
feet in diameter ; that is to say, it must have communi- 
cated to 17,888 tons of air a motion sufficiently intense 
to be appreciated by our organs of hearing. 

Musical sounds differ in pitch : some notes are high and 
shrill, others low and deep. Boys are chosen as choristers 

Q 



226 CAUSE OF PITCH. 

to produce the shrill notes ; men are chosen to produce 
the bass notes. Now, the sole difference here is, that the 
boy's organ vibrates more rapidly than the man's it sends 
a greater number of impulses per second to the ear. 
In like manner, a short string emits a higher note than a 
long one, because it vibrates more quickly. The greater 
the number of vibrations which any instrument performs 
in a given time, the higher will be the pitch of the note 
produced. The reason why the hum of a gnat is shriller 
than that of a beetle is that 'the wings of the small 
insect vibrate more quickly than those of the larger one. 
We can, with suitable arrangements, make those sonorous 
vibrations visible to the eye ; * and we also possess instru- 
ments which enable us to tell, with the utmost exacti- 
tude, the number of vibrations due to any particular note. 
By such instruments we learn that a gnat can execute 
many thousand flaps of its little wings in a second of time. 
In the study of nature the coarser phenomena, which 
come under the cognizance of the senses, often suggest to 
us the finer phenomena which come under the cognizance 
of the mind ; and thus the vibrations which produce sound, 
and which, as has been stated, can be rendered visible to 
the eye by proper means, first suggested that light might 
be due to a somewhat similar action. This is now the 
universal belief. A luminous body is supposed to have its 
atoms, or molecules, in a state of intense vibration. The 

* The vibrations of the air of a room in which a musical instrument is 
sounded may be made manifest by the way in which fine sand arranges 
itself upon a thin stretched membrane over which it is strewn ; and indeed 
Savart has thus rendered visible the vibrations of the tympanum itself. 
Every trace of sand was swept from a paper drum held in the clock-tower 
of Westminster when the Great Bell was sounded. Another way of showing 
the propagation of aerial pulses is to insert a small gas jet into a vertical 
glass tube about a foot in length, in which the flame may be caused to 
burn tranquilly. On pitching the voice to tlie note of an open tube a 
foot long, the little flame quivers, stretches itself, and responds by pro- 
ducing a clear melodious note of the same pitch as that which excited 
it. The flame will continue its song for hours without intermission. 



NATUEE OF LIGHT. 227 

motions of the atoms are supposed to be communicated to 
a medium suited to their transmission, as air is to the trans- 
mission of sound. This medium is called the luminiferous 
ether, and the little billows excited in it speed through it 
with amazing celerity, enter the pupil of the eye, pass 
through the humours, and break upon the retina or optic 
nerve, which is spread out at the back of the eye. Hence 
the tremors they produce are transmitted along the nerve 
to the brain, where they announce themselves as light. The 
swiftness with which the waves of light are propagated 
through the ether, is however enormously greater than 
that with which the waves of sound pass through the air. 
An aerial wave of sound travels at about the rate of 1100 
feet in a second: a wave of light leaves 192,000 miles 
behind it in the same time. 

Thus, then, in the case of sound, we have the sonorous 
body, the air, and the auditory nerve, concerned in the 
phenomenon ; in the case of light, we have the luminous 
body, the ether, and the optic nerve. The fundamental 
analogy of sound and light is thus before us, and it is 
easily remembered. But we must push the analogy 
further. We know that the white light which comes to 
us from the sun is made up of an infinite number of 
coloured rays. By refraction with a prism we can separate 
those rays from each other, and arrange them in the series 
of colours which constitute the solar spectrum. The 
rainbow is an imperfect or impure spectrum, produced by 
the drops of falling rain, but by prisms we can unravel the 
white light into pure red, orange, yellow, green, blue, 
indigo, and violet. Now, this spectrum is to the eye what 
the gamut is to the ear; each colour represents a note, 
and the different colours represent notes of different pitch. 
The vibrations which produce the impression of red are 
slower, and the waves which they produce are longer, than 
those to which we owe the sensation of violet ; while the 

Q 2 



228 CAUSE OF COLOUE. 

vibrations which excite the other colours are intermediate 
between these two extremes. This, then, is the second 
grand analogy between light and sound : Colour answers to 
Pitch. There is therefore truth in the figure when we say 
that the gentian of the Alps sings a shriller note than the 
wild rhododendron, and that the red glow of the mountains 
at sunset is of a lower pitch than the blue of the firmament 
at noon. 

These are not fanciful analogies. To the mind of the 
philosopher these waves of ether are almost as palpable 
and certain as the waves of the sea, or the ripples on the 
surface of a lake. The length of the waves, both of sound 
and light, and the number of shocks which they respec- 
tively impart to the ear and eye, have been the subjects of 
the strictest measurement. Let us here go through a 
simple calculation. It has been found that 39,000 waves 
of red light placed end to end would make up an inch. 
How many inches are there in 192,000 miles ? My 
youngest reader can make the calculation for himself, 
and find the answer to be 12,165,120,000 inches. It is 
evident that, if we multiply this number by 39,000, we 
shall obtain the number of waves of red light in 192,000 
miles; this number is 474,439,680,000,000. All these 
waves enter the eye in one second ; thus the expression 
"I see red colour," strictly means, " My eye is now in 
receipt of four hundred and seventy-four millions of 
millions of impulses per second." To produce the im- 
pression of violet light a still greater number of impulses 
is necessary; the wave-length of violet is the 57500"^ 
part of an inch, and the number of shocks imparted in a 
second by waves of this length is, in round numbers, six 
hundred and ninety-nine millions of millions. The other 
colours of the spectrum, as already stated, rise gradually 
in pitch from the red to the violet. 

A very curious analogy between the eye and ear may 



LENGTH OF ETHEREAL WAVES. 229 

here be noticed. The range of seeing is different in dif- 
ferent persons some see a longer spectrum than others ; 
that is to say, rays which are obscure to some are luminous 
to others. Dr. Wollaston pointed out a similar fact as regards 
hearing ; the range of which differs in different individuals. 
Savart has shown that a good ear can hear a musical note 
produced by 8 shocks in a second ; it can also hear a note 
produced by 24,000 shocks in a second ; but there are ears 
in which the range is much more limited. It is possible 
indeed to produce a sound which shall be painfully shrill to 
one person, while it is quite unheard by another. I once 
crossed a Swiss mountain in company with a friend ; a 
donkey was in advance of us, and the dull tramp of the 
animal was plainly heard by my companion ; but to me 
this sound was almost masked by the shrill chirruping of 
innumerable insects which thronged the adjacent grass ; 
my friend heard nothing of this, it lay quite beyond his 
range of hearing. 

A third and most important analogy between sound and 
light is now to be noted ; and it will be best understood 
by reference to something more tangible than either. 
When a stone is thrown into calm water a series of rings 
spread themselves around the centre of disturbance. If a 
second stone be thrown in at some distance from the first, 
the rings emanating from both centres will cross each other, 
and at those points where the ridge of one wave coincides 
with the ridge of another the water will be lifted to a 
greater height. At those points, on the contrary, where 
the ridge of one wave crosses the furrow of another, we 
have both obliterated, and the water restored to its ordinary 
level. Where two ridges or two" furrows unite, we have a 
case of coincidence ; but where a ridge and a furrow unite 
we have what is called interference. It is quite possible 
to send two systems of waves into the same channel, and 
to hold back one system a little, so that its ridges shall 



230 LIGHT ADDED TO LIGHT MAKES DARKNESS. 

coincide with the furrows of the other system. The 
" interference " would be here complete, and the waves 
thus circumstanced would mutually destroy each other, 
smooth water being the result. In this way, by the 
addition of motion to motion, rest may be produced. 

In a precisely similar manner two systems of sonorous 
waves can be caused to interfere and mutually to destroy 
each other : thus, by adding sound to sound, silence may 
be produced. Two beams of light also may be caused to 
interfere and effect their mutual extinction: thus, by 
adding light to light, we can produce darkness. Here 
indeed we have a critical analogy between sound and 
light the one, in fact, which compels the most profound 
thinkers of the present day to assume that light, like sound, 
is a case of undulatory motion. 

We see here the vision of the intellect prolonged 
beyond the boundaries of sense into the region of what 
might be considered mere imagination. But, unlike other 
imaginations, we can bring ours to the test of experiment ; 
indeed, so great a mastery have we obtained over these 
waves, which eye has not seen, nor ear heard, that we 
can with mathematical certainty cause them to coin- 
cide or to interfere, to help each other or to destroy 
each other, at pleasure. It is perhaps possible to be a 
little more precise here. Let two stones with a small 
distance between them be dropped into water at the 
same moment ; a system of circular waves will be formed 
round each stone. Let the distance from one little crest 
to the next following one be called the length of the 
wave, and now let us inquire what will take place at 
a point equally distant from the places where the two 
stones were dropped in. Fixing our attention upon the 
ridge of the first wave in each case, it is manifest that, 
as the water propagates both systems with the same velo- 
city, the two foremost ridges will reach the point in 



COINCIDENCE AND INTERFEEENCE. 231 

question at the same moment ; the ridge of one would 
therefore coincide with the ridge of the other, and the 
water at this point would be lifted to a height greater 
than that of either of the previous ridges. 

Again, supposing that by any means we had it in our 
power to retard one system of waves so as to cause the first 
ridge of the one to be exactly one wave length behind the 
first ridge of the other, when they arrive at the point 
referred to. It is plain that the first ridge of the retarded 
system now falls in with the second ridge of the unre- 
tarded system, and we have another case of coincidence. 
A little reflection will show the same to be true when one 
system is retarded any number of whole wave-lengths ; 
the first ridge of the retarded system will always, at the 
point referred to, coincide with a ridge of the unretarded 
system. 

But now suppose the one system to be retarded only 
half a wave-length ; it is perfectly clear that in this case 
the first ridge of the retarded system would fall in with 
the first furrow of the unretarded system, and instead of 
coincidence we should have interference. One system, in 
fact, would tend to make a hollow at the point referred to, 
the other would tend to make a hill, and thus the two 
systems would oppose and neutralise each other, so that 
neither the hollow nor the hill would be produced ; the 
water would maintain its ordinary level. What is here said 
of a single half-wave-length of retardation, is also true if 
the retardation amount to any odd number of half-wave- 
lengths. In all such cases we should have the ridge of 
the one system falling in with the furrow of the other ; a 
mutual destruction of the waves of both systems being the 
consequence. The same remarks apply when the point, 
instead of being equally distant from both stones, is an even 
or an odd number of semi-undulations farther from the 
one than from the other. In the former case we should 



232 LIQUID WAVES. 

have coincidence, and in the latter case interference, at 
the point in question. 

To the eye of a person who understands these things, 
nothing can be more interesting than the rippling of water 
under certain circumstances. By the action of interference 
its surface is sometimes shivered into the most beautiful 
mosaic, shifting and trembling as if with a kind of visible 
music. When the tide advances over a sea-beach on a 
calm and sunny day, and its tiny ripples enter, at various 
points, the clear shallow pools which the preceding tide 
had left behind, the little wavelets run and climb and cross 
each other, and thus form a lovely chasing, which has its 
counterpart in the lines of light converged by the ripples 
upon the sand underneath. When waves are skilfully 
generated in a vessel of mercury, and a strong light reflected 
from the surface of the metal is received upon a screen, the 
most beautiful effects may be observed. The shape of the 
vessel determines, in part, the character of the figures 
produced ; in a circular dish of mercury, for example, a dis- 
turbance at the centre propagates itself in circular waves, 
which after reflection again encircle the centre. If the 
point of disturbance be a little removed from the centre, 
the intersections of the direct and reflected waves produce 
the magnificent chasing shown in the annexed figure (16), 
which I have borrowed from the excellent work on Waves 
by the Messrs. Weber. The luminous figure reflected from 
such a surface is exceedingly beautiful. When the mer- 
cury is. lightly struck by a glass point, in a direction con- 
centric with the circumference of the vessel, the lines of 
light run round the vessel in mazy coils, interlacing and 
unravelling themselves in the most wonderful manner. If 
the vessel be square, a splendid mosaic is produced by the 
crossing of the direct and reflected waves. Description, 
however, can give but a feeble idea of these exquisite 
effects ; 



CHASING PEODUCED BY WAVES. 233 

" Thou canst not wave thy staff in the air, 

Or dip thy paddle in the lake, 
But it carves the brow of beauty there, 

And the ripples in rhymes the oar forsake." 

Now, all that we have said regarding the retardation of 
the waves of water, by a whole undulation and a semi- 




Fig. 16. 

undulation, is perfectly applicable to the case of light. 
Two luminous points may be placed near to each other 
so as to resemble the two stones dropped into the water ; and 
when the light of these is properly received upon a screen, 
or directly upon the retina, we find that at some places the 
action of the rays upon each other produces darkness, and at 
others augmented light. The former places are those where 
the rays emitted from one point are an odd number of semi- 
undulations in advance of the rays sent from the other ; 
the latter places are those where the difference of path 
described by the rays is either nothing, or an even number of 



234 



EFFECT OF EETAEDATION. 



semi-undulations. Supposing a and b (Fig. 17) to be two such 
sources of light, and s R a screen on which the light falls ; 
at a point Z, equally distant from a and 6, we have -light ; 
at a point eZ, where a d is half an undulation longer than 
b dj we have darkness ; at Z', where a I' is a whole wave- 
length, or two semi-undulations, longer than b Z', we again 
have light ; and at a point d r , where the difference is three 
semi- undulations, we have darkness ; and thus we obtain a 




Fig. 17. 



series of bright and dark spaces as we recede laterally 
from the central point I. 

Let a bit of tin foil be closely pasted upon a piece of glass, 
and the edge of a penknife drawn across the foil so as to 
produce a slit. Looking through this slit at a small and 
distant light, we find the light spread out in a direction at 
right angles to the slit, and if the light looked at be mono- 
chromatic, that is, composed of a single colour, we shall 
have a series of bright and dark bars corresponding to the 
points at which the rays from the different points of the 
slit alternately coincide and interfere upon the retina. 




c i c)baoaDac:ioDDCiDacnaDcnaaq3aDDQDnc3OQaDOOC3 a 




I \\X 



IMTEBFEBENCE SPECTRA, PEODUCED BY DIFFBACTION. 



FIG. 18. 



To face p. 235. 



CHEOMATIC EFFECTS. 235 

By properly drawing a knife across a sheet of letter-paper 
a suitable slit may also be obtained ; and those practised in 
such things can obtain the effect by looking through their 
fingers or their eyelashes. 

But if the light looked at be white, the light of a candle 
for example, or of a jet of gas, instead of having a series of 
bright and dark bars, we have the bars coloured. And see 
how beautifully this harmonizes with what has been already 
said regarding the different lengths of the waves which 
produce different colours. Looking again at Fig. 17 we see 
that a certain obliquity is necessary to cause one ray to be 
a whole undulation in advance of the other at the point /' ; 
but it is perfectly manifest that the obliquity must depend 
upon the length of the undulation ; a long undulation 
would require a greater obliquity than a short one ; red 
light, for example, requires a greater obliquity than blue 
light ; so that if the point V represents the place where the 
first bar of red light would be at its maximum strength, 
the maximum for blue would lie a little to the left of I' ; 
the different colours are in this way separated from each 
other, and exhibit themselves as distinct fringes when a dis- 
tant source of white light is regarded through a narrow slit. 

By varying the shape of the aperture we alter the form 
of the chromatic image. A circular aperture, for example, 
placed in front of a telescope through which a point 
of white light is regarded, is seen surrounded by a con- 
centric system of coloured rings. If we multiply our slits 
or apertures the phenomena augment in complexity and 
splendour. To give some notion of this I have copied 
from the excellent work of M. Schwerd the annexed figure 
(Fig. 18) which represents the gorgeous effect observed 
when a distant point of light is looked at through two 
gratings with slits of different widths.* A bird's feather 

* I am not aware whether in his own country, or in any other, a re- 
cognition at all commensurate with the value of the performance has 



236 COLOURS OF THIN FILMS. 

represents a peculiar system of slits, and the effect observed 
on properly looking through it is extremely interesting. 

There are many ways by which the retardation necessary 
to the production of interference is effected. The splendid 
colours of a soap-bubble are entirely due to interference ; 
the beam falling upon the transparent film is partially 
reflected at its outer surface, but a portion of it enters 
the film and is reflected at its inner surface. The latter 
portion having crossed the film and returned, is retarded, 
in comparison with the former, and, if the film be of 
suitable thickness, these two beams will clash and extin- 
guish each other, while another thickness will cause the 
beams to coincide and illuminate the film with a light of 
greater intensity. From what has been said it must be 
manifest that to make two red beams thus coincide a 
thicker film would be required than would be necessary for 
two blue or green beams ; thus, when the thickness of the 
bubble is suitable for the development of red, it is not 
suitable for the development of green, blue, &c. ; the 
consequence is that we have different Colours at different 
parts of the bubble. Owing to its compactness and to 
its being shaded by a covering of debris from the direct 
heat of the sun, the ice underneath the moraines of 
glaciers appears sometimes of a pitchy blackness. While 
cutting such ice with my axe I have often been surprised 
and delighted by sudden flashes of coloured light which 
broke like fire from the mass. These flashes were due 
to internal rupture, by which fissures were produced as 
thin as the film of a soap-bubble ; the colours being due 
to the interference of the light reflected from the opposite 
sides of the fissures. 

If spirit of turpentine, or olive oil, be thrown upon 
water, it speedily spreads in a thin film over the surface, 

followed Schwerd's admirable essay entitled ' The Phenomena of Dif- 
fraction deduced from the Theory of Undulation.' 



DIFFKACTION. 237 

and the most gorgeous 'chromatic phenomena may be thus 
produced. Oil of lemons is also peculiarly suited to this 
experiment. If water be placed in a tea-tray, and light 
of sufficient intensity be suffered to fall upon it, this light 
will be reflected from the upper and under surfaces of 
the film of oil, and the colours thus produced may be 
received upon a screen, and seen at once by many hundred 
persons. If the oil of cinnamon be used, fine colours are also 
obtained, and the breaking up of this film exhibits a most 
interesting case of molecular action. By using a kind of 
varnish, instead of oil, Mr. Delarue has imparted such 
tenacity to these films that they may be removed from 
the water on which they rest and preserved for any length 
of time. By such films the colours of certain beetles, and 
of the wings of certain insects, may be accurately imi- 
tated ; and a rook's feather may be made to shine with 
magnificent iridescences. The colours of tempered metals, 
and the beautiful metallochrome of Nobili are also due to 
a similar cause. 

These colours are called the colours of thin plates, and 
are distinguished in treatises on optics from the coloured 
bars and fringes above referred to, which are produced 
by diffraction, or the bending of the waves round the edge 
of an object. One result of this bending, which is of 
interest to us, was obtained by the celebrated Thomas 
Young. Permitting a beam of sunlight to enter a dark 
room through an aperture made with a fine needle, and 
placing in the path of the beam a bit of card one-thirtieth 
of an inch wide, he found the shadow of this card, or rather 
the line on which its shadow might be supposed to fall, 
always bright ; and he proved the effect to be due to the 
bending of the waves of ether round the two edges of the 
card, and their coincidence at the other side. It has, 
indeed, been shown by M. Poisson, that the centre of the 
shadow of a small circular opaque disk which stands in 



238 CLOUD IRIDESCENCES, ETC., EXPLAINED. 

the way of a beam diverging from a point is exactly as 
much illuminated as if the disk were absent. The sin- 
gular effects described by M. Necker in the letter quoted 
at page 178 at once suggest themselves here ; and we see 
how possible it is for the solar rays, in grazing a distant 
tree, so to bend round it as to produce upon the retina, 
where shadow might be expected, the impression of a tree 
of light.* Another effect of diffraction is especially in- 
teresting to us at present. Let the seed of lycopodium 
be scattered over a glass plate, or even like a cloud in 
the air, and let a distant point of light be regarded through 
it ; the luminous point will appear surrounded by a series 
of coloured rings, and when the light is intense, like the 
electric or the Drummond light, the effect is exceedingly 
fine. 

And now for the application of these experiments. I 
have already mentioned a series of coloured rings observed 
around the sun by Mr. Huxley and myself from the Rhone 
glacier ; I have also referred to the cloud iridescences on 
the Aletschhorn ; and to the colours observed during my 
second ascent of Monte Rosa, the magnificence of which 
is neither to be rendered by pigments nor described in 
words. All these splendid phenomena are, I believe, pro- 
duced by diffraction, the vesicles or spherules of water in the 
case of the cloud acting the part of the sporules in the case of 
the lycopodium. The coloured fringe which surrounds the 
Spirit of the Brocken, and the spectra which I have spoken 
of as surrounding the sun, are also produced by diffraction. 
By the interference of their rays in the earth's atmo- 
sphere the stars can momentarily quench themselves ; and 
probably to an intermittent action of this kind their twink- 
ling, and the swift chromatic changes already mentioned, 
are due. Does not all this sound more like a fairy 

* I think, however, that the strong irradiation from the glistening sides 
of the twigs and branches must also contribute to the result. 



EADIANT HEAT. 239 

tale than the sober conclusions of science ? What effort of 
the imagination could transcend the realities here pre- 
sented to us ? The ancients had their spheral melodies, 
but have not we ours, which only want a sense sufficiently 
refined to hear them? Immensity is filled with this 
music ; wherever a star sheds its light its notes are heard. 
Our sun, for example, thrills concentric waves through 
space, and every luminous point that gems our skies is 
surrounded by a similar system. I have spoken of the 
rising, climbing and crossing of the tiny ripples of a calm 
tide upon a smooth strand ; but what are they to those 
intersecting ripples of the " uncontinented deep " by which 
Infinity is engine-turned ! Crossing solar and stellar dis- 
tances, they bring us the light of sun and stars ; thrilled 
back from our atmosphere, they give us the blue radiance 
of the sky ; rounding liquid spherules, they clash at the 
other side, and the survivors of the tumult bear to our 
vision the wondrous cloud-dyes of Monte Rosa. 



Thus, then, we have been led from Sound to Light, and 
light now in its turn will lead us to Radiant Heat ; for 
in the order in which they are here mentioned the 
conviction arose that they are all three different kinds of 
motion. It has been said that the beams of the sun con- 
sist of rays of different colours, bub this is not a complete 
statement of the case. The sun emits a multitude of rays 
which are perfectly non-luminous ; and the same is true, in a 
still greater degree, of our artificial sources of illumination. 
Measured by the quantity of heat which they produce, 90 
per cent, of the rays emanating from a flame of oil are 



240 OBSCUEE KAYS. 

obscure; while 99 out of every 100 of those which ema- 
nate from an alcohol flame are of the same description.* 

In fact, the visible solar spectrum simply embraces an 
interval of rays of which the eye is formed tn take cog- 
nizance, but it by no means marks the limits of solar 
action. Beyond the violet end of the spectrum we have 
obscure rays capable of producing chemical changes, and 
beyond the red we have rays possessing a high heating 
power, but incapable of exciting the impression of light. 
This latter fact was first established by Sir William Her- 
schel, and it has been amply corroborated since. 

The belief now universally prevalent is, that the rays of 
heat differ from the rays of light simply as one colour 
differs from another. As the waves which produce red 
are longer than those which produce yellow, so the waves 
which produce this obscure heat are longer than those 
which produce red. In fact, it may be shown that the 
longest waves never reach the retina at all ; they are com- 
pletely absorbed by the humours of the eye. 

What is true of the sun's obscure rays is also true of 
calorific rays emanating from any obscure source, from 
our own bodies, for example, or from the surface of a 
vessel containing boiling water. We must, in fact, figure 
a warm body also as having its particles in a state of vibra- 
tion. When these motions are communicated from particle 
to particle of the body the heat is said to be conducted ; 
when, on the contrary, the particles transmit their vibra- 
tions through the surrounding ether, the heat is said to 
be radiant. This radiant heat, though obscure, exhibits a 
deportment exactly similar to light. It may be refracted 
and reflected, and collected in the focus of a mirror or of a 
suitable lens. The principle of interference also applies 
to it, so that by adding heat to heat we can produce cold. 
The identity indeed is complete throughout, and, recurring 
* Melloni. 



HEAT A KIND OF MOTION. 241 

to the analogy of sound, we might define this radiant heat 
to be light of too low a pitch to be visible. 

I have thus far spoken of obscure heat only ; but the 
selfsame ray may excite both light and heat. The red rays 
of the spectrum possess a very high heating power. It was 
once supposed that the heat of the spectrum was an 
essence totally distinct from its light ; but a profounder 
knowledge dispels this supposition, and leads us to infer 
that the selfsame ray, falling upon the nerves of feeling, 
excites heat, and falling upon the nerves of seeing, excites 
light. As the same electric current, if sent round a mag- 
netic needle, along a wire, and across a conducting liquid, 
produces different physical effects, so also the same agent 
acting upon different organs of the body affects our con- 
sciousness differently. 



(3.) 

Heat has been defined in the foregoing section as a 
motion of the molecules or atoms of a body ; but though 
the evidence in favour of this view is at present over- 
whelming, I do not ask the reader to accept it as a cer- 
tainty, if he feels sceptically disposed. In this case, I would 
only ask him to accept it as a symbol. Regarded as a mere 
physical image, a kind of paper-currency of the mind, 
convertible, in due time, into the gold of truth, the hypo- 
thesis will be found exceedingly useful. 

All known bodies possess more or less of this molecular 
motion, and all bodies are communicating it to the ether 
in which they are immersed. Ice possesses it. Ice before 
it melts attains a temperature of 32 Fahr., but the sub- 
stance in winter often possesses a temperature far below 
32, so that in rising to 32 it is luarmed. In experimenting 

R 



242 QUALITIES OF HEAT. 

with ice I have often had occasion to cool it to 100 and 
more below the freezing point, and to warm it afterwards 
up to 32. 

If then we stand before a wall of ice, the wall radiates 
heat to us, and we also radiate heat to it ; but the quan- 
tity which we radiate being greater than that which the 
ice radiates, we lose more than we gain, and are conse- 
quently chilled. If, on the contrary, we stand before a 
warm stove, a system of exchanges also takes place ; but 
here the quantity we. receive is in excess of the quantity 
lost, and we are warmed by the difference. 

In like manner the earth radiates heat by day and by 
night into space, and against the sun, moon, and stars. 
By day, however, the quantity received is greater than 
the quantity lost, and the earth is warmed ; by night the 
conditions are reversed ; the earth radiates more heat 
than is sent to her by the moon and stars, and she is con- 
sequently cooled. 

But here an important point is to be noted : the earth 
receives the heat of the sun, moon, and stars, in great part 
as luminous heat, but she gives it out as obscure heat. I do 
not now speak of the heat reflected by the earth into 
space, as the light of the moon is to us ; but of the heat 
which, after it has been absorbed by the earth, and has con- 
tributed to warm it, is radiated into space, as if the earth 
itself were its independent source. Thus we may properly 
say that the heat radiated from the earth is different in 
quality from that which the earth has received from the sun. 
In one particular especially does this difference of qua- 
lity show itself; besides being non-luminous, the heat 
radiated from the earth is more easily intercepted anc 
absorbed by almost all transparent substances. A 
portion of the sun's rays, for example, can pass instan- 
taneously through a thick sheet of water; gunpowdei 
could easily be fired by the heat of the sun's rays cop- 



THE ATMOSPHEKE LIKE A RATCHET. 243 

verged by passing through a thick water lens ; the drops 
upon leaves in greenhouses often act as lenses, and cause 
the sun to burn the leaves upon which they rest. But 
with regard to the rays of heat emanating from an ob- 
scure source, they are all absorbed by a layer of water 
less than the 20th of an inch in thickness : water is 
opaque to such rays, and cuts them off almost as effectually 
as a metallic screen. The same is true of other liquids, 
and also of many transparent solids. 

Assuming the same to be true of gaseous bodies, that 
they also intercept the obscure rays much more readily 
than the luminous ones, it would follow that while the 
sun's rays penetrate our atmosphere with freedom, the 
change which they undergo in warming the earth deprives 
them in a measure of this penetrating power. They can 
reach the earth, but they cannot get lack ; thus the atmo- 
sphere acts the part of a ratchet-wheel in mechanics ; it 
allows of motion in one direction, but prevents it in the 
other. 

De Saussure, Fourier, M. Pouillet, and Mr. Hopkins have 
developed this speculation, and drawn from it consequences 
of the utmost importance ; bat it nevertheless rested 
upon a basis of conjecture. Indeed some of the eminent 
men above-named deemed its truth beyond the possibility 
of experimental verification. Melloni showed that for a dis- 
tance of 18 or 20 feet the absorption of obscure rays by 
the atmosphere was absolutely inappreciable. Hence, the 
total absorption being so small as to elude even Melloni's 
delicate tests, it was reasonable to infer that differences of 
absorption, if such existed at all, must be far beyond the 
reach of the finest means which we could apply to detect 
them. 

This exclusion of one of the three states of material 
aggregation from the region of experiment was, however, 
by no means satisfactory ; for our right to infer, from the 



244 DIFFEEENCES OF ABSORPTION BY GASES. 

deportment of a solid or a liquid towards radiant heat, the 
deportment of a gas, is by no means evident. In both 
liquids and solids we have the molecules closely packed, 
and more or less chained by the force of cohesion ; in 
gases, on the contrary, they are perfectly free, and widely 
separated. How do we know that the interception of 
radiant heat by liquids and solids may not be due to 
an arrangement and comparative rigidity of their parts, 
which gases do not at all share ? The assumption which 
took no note of such a possibility seemed very insecure, 
and called for verification. 

My interest in this question was augmented by the 
fact, that the assumption referred to lies, as will be seen, at 
the root of the glacier question. I therefore endeavoured 
to fill the gap, and to do for gases and vapours what had 
been already so ably done for liquids and solids by Mel- 
loni. I tried the methods heretofore pursued, and found 
them unavailing ; oxygen, hydrogen, nitrogen, and atmo- 
spheric air, examined by such methods, showed no action 
upon radiant heat. Nature was dumb, but the question 
occurred, " Had she been addressed in the proper lan- 
guage ? " If the experimentalist is convinced of this, he 
will rest content even with a negative ; but the absence 
of this conviction is always a source of discomfort, and a 
stimulus to try again. 

The principle of the method finally applied is all that 
can here be referred to; and it, I hope, will be quite 
intelligible. Two beams of heat, from two distinct sources, 
were allowed to fall upon the same instrument,* and to 
contend there for mastery. When both beams were per- 
fectly equal, they completely neutralized each other's 
action ; but when one of them was in any sensible degree 
stronger than the other, the predominance of the former 
was shown by the instrument. It was so arranged that 

* The opposite faces of a thermo-electric pile. 



SELECTED HEAT. 245 

one of the conflicting beams passed through a tube which 
could be exhausted of air, or filled with any gas; thus 
varying at pleasure the medium through which it passed. 
The question then was, supposing the two beams to be 
equal when the tube was filled with air, will the ex- 
hausting of the tube disturb the equality ? The answer 
was affirmative; the instrument at once showed that a 
greater quantity of heat passed through the vacuum than 
through the air. 

The experiment was so arranged that the effect thus 
produced was very large as measured by the indications of 
the instrument. But the action of the simple gases, oxygen, 
hydrogen, and nitrogen, was incomparably less than that 
produced by some of the compound gases, while these 
latter again differed widely from each other. Vapours ex- 
hibited differences of equal magnitude. The experiments 
indeed proved that gaseous bodies varied among them- 
selves, as to their power of transmitting radiant heat, just 
as much as liquids and solids. It was in the highest degree 
interesting to observe how a gas or vapour of perfect trans- 
parency, as regards light, acted like an opaque screen upon 
the heat. To the eye, the gas within the tube might be 
as invisible as the air itself, while to the radiant heat it 
behaved like a cloud which it was almost impossible to 
penetrate. 

Applying the same method, I have found that from the 
sun, from the electric light, or from the lime-light, a 
large amount of heat can be selected, which is un- 
affected not only by air, but by the most energetic gases 
that experiment has revealed to me; while this same 
heat, when it has its quality changed by being rendered 
, obscure, is powerfully intercepted. Thus the bold and 
beautiful speculation above referred to has been made an 
experimental fact ; the radiant heat of the sun does cer- 
tainly pass through the atmosphere to the earth with 



246 POSSIBLE HEAT OF NEPTUNE, 

greater facility than the radiant heat of the earth can 
escape into space. 

It is probable that, were the earth unfurnished with this 
atmospheric swathing, its conditions of temperature would 
be such as to render it uninhabitable by man ; and it is 
also probable that a suitable atmosphere enveloping the 
most distant planet might render it, as regards tempera- 
ture, perfectly habitable. ' If the planet Neptune, for 
example, be surrounded by an atmosphere which permits 
the solar and stellar rays to pass towards the planet, but 
cuts off the escape of the warmth which they excite, it is 
easy to see that such an accumulation of heat may at 
length take place as to render the planet a comfortable 
habitation for beings constituted like ourselves.* 

But let us not wander too far from our own concerns. 
Where radiant heat is allowed to fall upon an absorbing 
substance, a certain thickness of the latter is always 
necessary for the absorption. Supposing we place a thin 
film of glass before a source of heat, a certain percentage of 
the heat will pass through the glass, and the remainder 
will be absorbed. Let the transmitted portion fall upon a 
second film similar to the first, a smaller percentage than 
before will be absorbed. A third plate would absorb still 
less, a fourth still less ; and, after having passed through a 
sufficient number of layers, the heat would be so sifted that 
all the rays capable of being absorbed by glass would be 
abstracted from it. Suppose all these films to be placed 
together so as to form a single thick plate of glass, it is 
evident that the plate must act upon the heat which 
falls upon it, in such a manner that the major portion is 
absorbed near the surface at which the heat enters. This 
has been completely verified by experiment. 

Applying this to the heat radiated from the earth, it is 

* See a most interesting paper on this subject by Mr. Hopkins in the 
Cambridge ' Transactions,' May, 1856. 



COLD OF UPPER ATMOSPHERE. 247 

manifest that the greatest quantity of this heat will be 
absorbed by the lowest atmospheric strata. And here we 
find ourselves brought, by considerations apparently re- 
mote, face to face with the fact upon which the existence 
of all glaciers depends, namely, the comparative coldness 
of the upper regions of the atmosphere. The sun's rays 
can pass in a great measure through these regions without 
heating them; and the earth's rays, which they might 
absorb, hardly reach them at all, but are intercepted by 
the lower portions of the atmosphere.* 

Another cause of the greater coldness of the higher 
atmosphere is the expansion of the denser air of the lower 
strata when it ascends. The dense air makes room for 
itself by pushing back the lighter and less elastic air which 
surrounds it : it does work, and, to perform this work, a 
certain amount of heat must be consumed. It is the con- 
sumption of this heat its absolute annihilation as heat 
that chills the expanded air, and to this action a share of 
the coldness of the higher atmosphere must undoubtedly 
be ascribed. A third cause of the difference of tempera- 
ture is the large amount of heat communicated, by way 
of contact, to the air of the earth's surface ; and a fourth 
and final cause is the loss endured by the highest strata 
through radiation into space. 

* See M. Pouillet's important Memoir on Solar Radiation. Taylor's 
Scientific Memoirs, vol. iv. p. 44. 



248 THE SNOW-LINE. 



ORIGIN OF GLACIERS. 
(4) 

HAVING thus accounted for the greater cold of the 
higher atmospheric regions, its consequences are next to 
be considered. One of these is, that clouds formed in 
the lower portions of the atmosphere, in warm and tem- 
perate latitudes, usually discharge themselves upon the 
earth as rain ; while those formed in the higher regions 
discharge themselves upon the mountains as snow. The 
snow of the higher atmosphere is often melted to rain in 
passing through the warmer lower strata : nothing indeed is 
more common than to pass, in descending a mountain, 
from snow to rain ; and I have already referred to a case 
of this kind. The appearance of the grassy and pine- 
clad alps, as seen from the valleys after a wet night, is 
often strikingly beautiful; the level at which the snow 
turned to rain being distinctly marked upon the slopes. 
Above this level the mountains are white, while below it 
they are green. The eye follows this snow-line with ease 
along the mountains, and when a sufficient extent of 
country is commanded its regularity is surprising. 

The term " snow-line," however, which has been here 
applied to a local and temporary phenomenon, is commonly 
understood to mean something else. In the case just 
referred to it marked the place where the supply of solid 
matter from the upper atmospheric regions, during a 
single fall, was exactly equal to its consumption; but 
the term is usually understood to mean the line along 
which the quantity of snow which falls annually is melted, 
and no more. Below this line each year's snow is com- 



MOUNTAINS UNLOADED BY GLACIERS. 249 

pletely cleared away by the summer heat ; above it a 
residual layer abides, which gradually augments in thick- 
ness from the snow-line upwards. 

Here then we have a fresh layer laid on every year ; 
and it is evident that, if this process continued without 
interruption, every mountain which rises above the 
snow-line must augment annually in height ; the waters 
of the sea thus piled, in a solid form, upon the summits 
of the hills, would raise the latter to an indefinite 
elevation. But, as might be expected, the snow upon steep 
mountain-sides frequently slips and rolls down in avalanches 
into warmer regions, where it is reduced to water. A 
comparatively small quantity of the snow is, however, thus 
got rid of, and the great agent which Nature employs 
to relieve her overladen mountains is the glaciers. 

Let us here avoid an error which may readily arise out 
of the foregoing reflections. The principal region of clouds 
and rain and snow extends only to a limited distance 
upwards in the atmosphere ; the highest regions contain 
very little moisture, and were our mountains sufficiently 
lofty to penetrate those regions, the quantity of snow 
falling upon their summits would be too trifling to resist 
the direct action of the solar rays. These would annually 
clear the summits to a certain level, and hence, were 
our mountains high enough, we should have a superior, 
as well as an inferior, snow-line ; the region of perpetual 
snow would form a belt, below which, in summer, snowless 
valleys and plains would extend, and above which snowless 
summits would rise. 



(5.) 

At its origin then a glacier is snow at its lower ex- 
tremity it is ice. The blue blocks that arch the source of 



250 WHITE AND BLUE ICE. 

the Arveiron were once powdery snow upon the slopes of the 
Col du Geant. Could our vision penetrate into the body 
of the glacier, we should find that the change from white 
to blue essentially consists in the gradual expulsion of the 
air which was originally entangled in the meshes of the 
fallen snow. Whiteness always results from the intimate 
and irregular mixture of air and a transparent solid ; a 
crushed diamond would resemble snow ; if we pound 
the most transparent rock-salt into powder we have a 
substance as white as the whitest culinary salt ; and the 
colourless glass vessel which holds the salt would also, if 
pounded, give a powder as white as the salt itself. It is a 
law of light that in passing from one substance to another 
possessing a different power of refraction, a portion of it is 
always reflected. Hence when light falls upon a transparent 
solid mixed with air, at each passage of the light from the air 
to the solid and from the solid to the air a portion of it is 
reflected ; and, in the case of a powder, this reflection 
occurs so frequently that the passage of the light is prac- 
tically cut off. Thus, from the mixture of two perfectly 
transparent substances, we obtain an opaque one ; from the 
intimate mixture of air and water we obtain foam ; clouds 
owe their opacity to the same principle ; and the condensed 
steam of a locomotive casts a shadow upon the fields 
adjacent to the line, because the sunlight is wasted in 
echoes at the innumerable limiting surfaces of water and 
air. 

The snow which falls upon high mountain-eminences 
has often a temperature far below the freezing point 
of water. Such snow is dry, and if it always con- 
tinued so the formation of a glacier from it would be 
impossible. The first action of the summer's sun is to 
raise the temperature of the superficial snow to 32, and 
afterwards to melt it. The water thus formed percolates 
through the colder mass underneath, and this I take to be 



AIK-BUBBLES IN ICE. 251 

the first active agency in expelling the air entangled in 
the snow. But as the liquid trickles over the surfaces of 
granules colder than itself it is partially deposited in a 
solid form on these surfaces, thus augmenting the size of 
the granules, and cementing them together. When the 
mass thus formed is examined, the air within it is found as 
round bubbles. Now it is manifest that the air caught in the 
irregular interstices of the snow can have no tendency to 
assume this form so long as the snow remains solid ; 
but the process to which I have referred the saturation 
of the lower portions of the snow by the water produced 
by the melting of the superficial portions enables the 
air to form itself into globules, and to give the ice of 
the neve its peculiar character. Thus we see that, though 
the sun cannot get directly at the deeper portions of the 
snow, by liquefying the upper layer he charges it with 
heat, and makes it his messenger to the cold subjacent 
mass. 

The frost of the succeeding winter may, I think, or may 
not, according to circumstances, penetrate through this 
layer, and solidify the water which it still retains in its 
interstices. If the winter set in with clear frosty wea- 
ther, the penetration will probably take place ; but if 
heavy snow occur at the commencement of winter, thus 
throwing a protective covering over the neve, freezing to 
any great depth may be prevented. Mr. Huxley's idea 
seems to be quite within the range of possibility, that 
water-cells may be transmitted from the origin of the 
glacier to its end, retaining their contents always liquid. 

It was formerly supposed, and is perhaps still supposed 
by many, that the snow of the mountains is converted into 
the ice of the glacier by the process of saturation and 
freezing just indicated. But the frozen layer would not yet 
resemble glacier ice ; it is only at the deeper portions of 
the neve that we find an approximation to the true ice of 



252 SNOW PKESSED TO ICE. 

the glacier. This brings us to the second great agent in 
the process of glacification, namely, pressure. The ice of the 
neve at 32 may be squeezed or crushed with extreme fa- 
cility ; and if the force be applied slowly and with caution, 
the yielding of the mass may be made to resemble the 
yielding of a plastic body. In the depths of the neve, 
where each portion of the ice is surrounded by a resistant 
mass, rude crushing is of course out of the question. 
The layers underneath yield with extreme slowness to 
the pressure of the mass above them ; they are squeezed, 
but not rudely fractured ; and even should rude fracture 
occur, the ice, as shall subsequently be shown, possesses 
the power of restoring its own continuity. Thus, then, 
the lower portions of the neve are removed by pressure 
more and more from the condition of snow, the air-bubbles 
which give to the neve-icQ its whiteness are more and 
more expelled, and this process, continued throughout the 
entire glacier, finally brings the ice to that state of mag- 
nificent transparency which we find at the termination 
of the glacier of Eosenlaui and elsewhere. This is all 
capable of experimental proof. The Messrs. Schlagint- 
weit compressed the snow of the neve to compact ice ; and 
I have myself frequently obtained slabs of ice from snow 
in London. 



LONG WAVES MOST ABSORBED. 253 

COLOUR OF WATER AND ICE. 

(6.) 

THE sun is continually sending forth waves of different 
lengths, all of which travel with the same velocity through 
the ether. When these waves enter a prism of glass they 
are retarded, but in different degrees. The shorter waves 
suffer the greatest retardation, and in consequence of this 
are most deflected from their straight course. It is this 
property which enables us to separate one from the other 
in the solar spectrum, and this separation proves that the 
waves are by no means inextricably entangled with each 
other, but that they travel independently through space. 

In consequence of this independence, the same body 
may intercept one system of waves while it allows another 
to pass : on this quality, indeed, depend all the phenomena 
of colour. A red glass, for example, is red because it 
is so constituted that it destroys the shorter waves which 
produce the other colours, and transmits only the waves 
which produce red. I may remark, however, that scarcely 
any glass is of a pure colour ; along with the predominant 
waves, some of the other waves are permitted to pass. 
The colours of flowers are also very impure ; in fact, to 
get pure colours we must resort to a delicate prismatic 
analysis of white light. 

It has already been stated that a layer of water less than 
the twentieth of an inch in thickness suffices to stop and 
destroy all waves of radiant heat emanating from an obscure 
source. The longer waves of the obscure heat cannot get 
through water, and I find that all transparent com- 
pounds which contain hydrogen are peculiarly hostile 
to the longer undulations. It is, I think, the presence of 



254 FINAL COLOUR OF ICE AND WATER BLUE. 

this element in the humours of the eye which prevents the 
extra red rays of the solar spectrum from reaching the 
retina. It is interesting to observe that while bisulphide 
of carbon, chloride of phosphorus, and other liquids which 
contain no hydrogen, permit a large portion of the rays 
emanating from an iron or copper ball, at a heat below 
redness, to pass through them with facility, the same 
thickness of substances equally transparent, but which con- 
tain hydrogen, such as ether, alcohol, water, or the vitreous 
humour of the eye of an ox, completely intercepts these 
obscure rays. The same is true of solid bodies ; a very 
slight thickness of those which contain hydrogen offers an 
impassable barrier to all rays emanating from a non- 
luminous source.* But the heat thus intercepted is by no 
means lost ; its radiant form merely is destroyed. Its waves 
are shivered upon the particles of the body, but they 
impart warmth to it, while the heat which retains its 
radiant form contributes in no way to the warmth of the 
body through which it passes. 

Water then absorbs all the extra red rays of the sun, 
and if the layer be thick enough it invades the red rays 
themselves. Thus the greater the distance the solar beams 
travel through pure water the more are they deprived 
of those components which lie at the red end of the 
spectrum. The consequence is, that the light finally 
transmitted by the water, and which gives to it its colour, 
is blue. 

I find the following mode of examining the colour of 
water both satisfactory and convenient : A tin tube, 
fifteen feet long and three inches in diameter, has its two 
ends stopped securely by pieces of colourless plate glass. It 

* What is here stated regarding hydrogen is true of all the liquids and 
solids which have hitherto been examined, but whether any exceptions 
occur, future experience must determine. It is only when in combination 
that it exhibits this impermeability to the obscure rays. 



EXPEKIMENT. 255 

is placed in a horizontal position, and pure water is poured 
into it through a small lateral pipe, until the liquid reaches 
half way up the glasses at the ends ; the tube then holds 
a semi-cylinder of water and a semi-cylinder of air. A 
white plate, or a sheet of white paper, well illuminated, is 
then placed at a little distance from one end of the tube, 
and is looked at through the tube. Two semicircular 
spaces are then seen, one by the light which has passed 
through the air, the other by the light which has passed 
through the water ; and their proximity furnishes a means of 
comparison, which is absolutely necessary in experiments 
of this kind. It is always found that, while the former 
semicircle remains white, the latter one is vividly coloured.* 

When the beam from an electric lamp is sent through this 
tube, and a convex lens is placed at a suitable distance from 
its most distant end, a magnified image of the coloured 
and uncoloured semicircles may be projected upon a 
screen. Tested thus, I have sometimes found, after rain, 
the ordinary pipe-water of the Royal Institution quite 
opaque ; while, under other circumstances, I have found 
the water of a clear green. The pump- water of the Insti- 
tution thus examined exhibits a rich sherry colour, while 
distilled water is blue-green. 

The blueness of the Grotto of Capri is due to the fact 
that the light which enters it has previously traversed a 
great depth of clear water. According to Bunsen's account, 
the laugs, or cisterns of hot water, in Iceland must be 
extremely beautiful. The water contains silica in solution, 
which, as the walls of the cistern arose, was deposited 
upon them in fantastic incrustations. These, though white, 
when looked at through the water appear of a lovely blue, 
which deepens in tint as the vision plunges deeper into the 
liquid. 

* In my own experiments I have never yet been able to obtain a pure 
blue, the nearest approach to it being a blue-green. 



256 ICE OPAQUE TO EADIANT HEAT. 

Ice is a crystal formed from this blue liquid, the 
colour of which it retains. Ice is the most opaque of 
transparent solids to radiant heat, as water is the most 
opaque of liquids. According to Melloni, a plate of ice one 
twenty-fifth of an inch thick, which permits the rays of 
light to pass without sensible absorption, cuts off 94 per 
cent, of the rays of heat issuing from a powerful oil lamp, 
99J per cent, of the rays issuing from incandescent pla- 
tinum, and the whole of the rays issuing from an obscure 
source. The above numbers indicate how large a portion 
of the rays emitted by our artificial sources of light is 
obscure. 

When the rays of light pass through a sufficient thickness 
of ice the longer waves are, as in the case of water, more and 
more absorbed, and the final colour of the substance is there- 
fore blue. But when the ice is filled with minute air-bubbles, 
though we should loosely call it white, it may exhibit, even 
in small pieces, a delicate blue tint. This, I think, is 
due to the frequent interior reflection which takes place 
at the surfaces of the air-cells ; so that the light which 
reaches the eye from the interior may, in consequence of 
its having been reflected hither and thither, really have 
passed through a considerable thickness of ice. The same 
remark, as we have already seen, applies to the delicate 
colour of newly fallen snow. 



NEWTON'S HYPOTHESIS. 257 



COLOURS OF THE SKY. 



IN treating of the Colours of Thin Plates we found that a 
certain thickness was necessary to produce blue, while 
a greater thickness was necessary for red. With that 
wonderful power of generalization which belonged to him, 
Newton thus applies this apparently remote fact to the 
blue of the sky : " The blue of the first order, though 
very faint and little, may possibly be the colour of some 
substances, and particularly the azure colour of the skies 
seems to be of this order. For all vapours, when they 
begin to condense and coalesce into small parcels, become 
first of that bigness whereby such an azure is reflected, 
before they can constitute clouds of other colours. And 
so, this being the first colour which vapours begin to 
reflect, it ought to be the colour of the finest and rnosfc 
transparent skies, in which vapours are not arrived at that 
grossness requisite to reflect other colours, as we find it is 
by experience." 

M. Clausius has written a most interesting paper, 
which he endeavours to show that the minute particles of 
water which are supposed by Newton to reflect the light, 
cannot be little globes entirely composed of water, but 
bladders or hollow spheres ; the vapour must be in what 
is generally termed the vesicular state. He was followed 
by M. Briicke, whose experiments prove that the sus- 
pended particles may be so small that the reasoning of 
M. Clausius may not apply to them. 

But why need we assume the existence of such particles 
at all ? why not assume that the colour of the air is blue, 
and renders the light of the sun blue, after the fashion of a 

s 



258 GOETHE'S HYPOTHESIS. 

blue glass or a solution of the sulphate of copper ? I have 
already referred to the great variation which the colour 
of the firmament undergoes in the Alps, and have re- 
marked that this seems to indicate that the blue depends 
upon some variable constituent of the atmosphere. Fur- 
ther, we find that the blue light of the sky is reflected 
light ; and there must be something in the atmosphere 
capable of producing this reflection ; but this thing, what- 
ever it is, produces another effect which the blue glass or 
liquid is unable to produce. These transmit blue light, 
whereas, when the solar beams have traversed a great 
length of air, as in the morning or the evening, they are 
yellow, or orange, or even blood-red, according to the 
state of the atmosphere : the transmitted light and the 
reflected light of the atmosphere are then totally different 
in colour. 

Goethe, in his celebrated ' Farbenlehre,' gives a theory 
of the colour of the sky, and has illustrated it by a series 
of striking facts. He assumed two principles in the uni- 
verse Light and Darkness and an intermediate stage of 
Turbidity. When the darkness is seen through a turbid 
medium on which the light falls, the medium appears 
blue ; when the light itself is viewed through such a 
medium, it is yellow, or orange, or ruby-red. This he 
applies to the atmosphere, which sends us blue light, or 
red, according as the darkness of infinite space, or the 
bright surface of the sun, is regarded through it. 

As a theory of colours Goethe's work is of no value, but 
the facts which he has brought forward in illustration of the 
action of turbid media are in the highest degree interest- 
ing. He refers to the blueness of distant mountains, of 
smoke, of the lower part of the flame of a candle (which if 
looked at with a white surface behind it completely dis- 
appears), of soapy water, and of the precipitates of various 
resins in water. One of his anecdotes in connexion with 



SUSPENDED PARTICLES. 259 

this subject is extremely curious and instructive. The 
portrait of a very dignified theologian having suffered 
from dirt, it was given to a painter to be cleaned. The 
clergyman was drawn in a dress of black velvet, over 
which the painter, in the first place, passed his sponge. To 
his astonishment the black velvet changed to the colour of 
blue plush, and completely altered the aspect of its 
wearer. Goethe was informed of the fact; the experi- 
ment was repeated in his presence, and he at once solved 
it by reference to his theory. The varnish of the picture 
when mixed with the water formed a turbid medium, and 
the black coat seen through it appeared blue ; when the 
water evaporated the coat resumed its original aspect. 

With regard to the real explanation of these effects, it 
may be shown, that, if a beam of white light be sent 
through a liquid which contains extremely minute parti- 
cles in a state of suspension, the short waves are more 
copiously reflected by such particles than the long ones ; 
blue, for example, is more copiously reflected than red. 
This may be shown by various fine precipitates, but the 
best is that of Briicke. We know that mastic and various 
resins are soluble in alcohol, and are precipitated when 
the solution is poured into water : Eau de Cologne, for ex- 
ample, produces a white precipitate when poured into 
water. If however this precipitate be sufficiently diluted, 
it gives the liquid a bluish colour by reflected light. 
Even when the precipitate is very thick and gross, and 
floats upon the liquid like a kind of curd, its under por- 
tions often exhibit a fine blue. To obtain particles of a 
proper size, Briicke recommends 1 gramme of colourless 
mastic to be dissolved in 87 grammes of alcohol, and 
dropped into a beaker of water, which is kept in a state 
of agitation. In this way a blue resembling that of the 
firmament may be produced. It is best seen when a black 
cloth is placed behind the glass ; but in certain positions 

s 2 



260 THE SUN THROUGH LONDON SMOKE. 

this blue liquid appears yellow ; and these are the positions 
when the transmitted light reaches the eye. It is evident 
that this change of colour must necessarily exist ; for the 
blue being partially withdrawn by more copious reflec- 
tion, the transmitted light must partake more or less of 
the character of the complementary colour ; though it does 
not follow that they should be exactly complementary to 
each other. 

When a long tube is filled with clear water, the colour 
of the liquid, as before stated, shows itself by transmitted 
light. The effect is very interesting when a solution of 
mastic is permitted to drop into such a tube, and the fine 
precipitate to diffuse itself in the water. The blue-green 
of the liquid is first neutralized, and a yellow colour 
shows itself; on adding more of the solution the colour 
passes from yellow to orange, and from orange to blood- 
red. With a cell an inch and a half in width, containing 
water, into which the solution of mastic is suffered to drop, 
the same effect may be obtained. If the light of an 
electric lamp be caused to form a clear sunlike disk upon 
a white screen, the gradual change of this light by aug- 
mented precipitation into deep glowing red, resembling 
the colour of the sun when seen through fine London 
smoke, is exceedingly striking. Indeed the smoke acts, in 
some measure, the part of our finely-suspended matter. 

By such means it is possible to imitate the phenomena 
of the firmament ; we can produce its pure blue, and cause 
it to vary as in nature. The milkiness which steals over 
the heavens, and enables us to distinguish one cloudless 
day from another, can be produced with the greatest ease. 
The yellow, orange, and red light of the morning and 
evening can also be obtained : indeed the effects are so 
strikingly alike as to suggest a common origin that the 
colours of the sky are due to minute particles diffused 
through the atmosphere. These particles are doubtless 



MORNING AND EVENING RED. 261 

the condensed vapour of water, and its variation in quality 
and amount enables us to understand the variability of the 
firmamental blue, and of the morning and the evening red. 
Professor Forbes, moreover, has made the interesting ob- 
servation that the steam of a locomotive, at a certain stage 
of its condensation, is blue or red according as it is viewed 
by reflected or transmitted light. 

These considerations enable us to account for a number 
of facts of common occurrence. Thin milk, when poured 
upon a black surface, appears bluish. The milk is colour- 
less ; that is, its blueness is not due to absorption, but to a 
separation of the light by the particles suspended in the 
liquid. The juices of various plants owe their blueness to 
the same cause ; but perhaps the most curious illustration 
is that presented by a blue eye. Here we have no true 
colouring matter, no proper absorption ; but we look 
through a muddy medium at the black chproid coat within 
the eye, and the medium appears blue.* 

Is it not probable that this action of finely-divided 
matter may have some influence on the colour of some of 
the Swiss lakes as that of Geneva for example ? This 
lake is simply an expansion of the river Rhone, which 
rushes from the end of the Rhone glacier, as the Arveiron 
does from the end of the Mer de Glace. Numerous other 
streams join the Rhone right and left during its down- 
ward course ; and these feeders, being almost wholly de- 
rived from glaciers, join the Rhone charged with the 
finer matter which these in their motion have ground 
from the rocks over which they have passed. But the 
glaciers must grind the mass beneath them to particles 
of all sizes, and I cannot help thinking that the finest of 
them must remain suspended in the lake throughout its 
entire length. Faraday has shown that a precipitate of 
gold may require months to sink to the bottom of a 
* Helmholtz, ' Das Sehen des Menschen.' 



262 COLOUR OF SWISS LAKES. 

bottle not more than five inches high, and in all probability 
it would require ages of calm subsidence to bring all 
the particles which the Lake of Geneva contains to its 
bottom. It seems certainly worthy of examination whether 
such particles suspended in the water contribute to the 
production of that magnificent blue which has excited 
the admiration of all who have seen it under favourable 
circumstances. 



LATERAL MORAINES. 263 



THE MORAINES. 

' (8.) 

THE surface of the glacier does not long retain the shining 
whiteness of the snow from which it is derived. It is 
flanked by mountains which are washed by rain, dislocated ^ 
by frost, riven by lightning, traversed by avalanches, and 
swept by storms. The lighter de*bris is scattered by the 
winds far and wide over the glacier, sullying the purity of 
its surface. Loose shingle rattles at intervals down the 
sides of the mountains, and falls upon the ice where it 
touches the rocks. Large rocks are continually let loose, 
which come jumping from ledge to ledge, the cohesion of 
some being proof against the shocks which they experience ; 
while others, when they hit the rocks, burst like bomb- 
shells, and shower their fragments upon the ice. 

Thus the glacier is incessantly loaded along its borders 
with the ruins of the mountains which limit it ; and it is 
evident that the quantity of rock and rubbish thus cast 
upon the glacier depends upon the character of the ad- 
jacent mountains. Where the summits are bare and 
friable, we may expect copious showers ; where they are 
resistant, and particularly where they are protected by a 
covering of ice and snow, the quantity will be small. As 
the glacier moves downward, it carries with it the load 
deposited upon it. Long ridges of debris thus flank the 
glacier, and these ridges are called lateral moraines. 
Where two tributary glaciers join to form a trunk-glacier, 
their adjacent lateral moraines are laid side by side 
at the place of confluence, thus constituting a ridge 
which runs along the middle of the trunk-glacier, and 



264 MEDIAL AND TERMINAL MORAINES. 

which is called a medial moraine. The rocks and debris 
carried down by the glacier are finally deposited at its 
lower extremity, forming there a terminal moraine. 

It need hardly be stated that the number of medial 
moraines is only limited by the number of branch glaciers. 
If a glacier have but two branches, it will have only one 
medial moraine ; if it have three branches, it will have two 
medial moraines ; if n branches, it will have n 1 medial 
moraines. The number of medial moraines, in short, is 
always one less than the number of branches. A glance at 
the annexed figure will reveal the manner in which the 
lateral moraines of the Mer de Glace unite to form medial 
ones. (See Fig. 19.) 

When a glacier diminishes in size it leaves its lateral 
moraines stranded on the flanks of the valleys. Successive 
shrinkings may thus occur, and have occurred at intervals 
of centuries ; and a succession of old lateral moraines, such 
as many glacier-valleys exhibit, is the consequence. The 
Mer de Glace, for example, has its old lateral moraines, 
which run parallel with its present ones. The glacier may 
also dimmish in length at distant intervals ; the result being 
a succession of more .or less concentric terminal moraines. 
In front of the Rhone-glacier we have six or seven such 
moraines, and the Mer de Glace also possesses a series of 
them. 

Let us now consider the effect produced by a block of 
stone upon the surface of a glacier. The ice around it 
receives the direct rays of the sun, and is acted on by the 
warm air ; it is therefore constantly melting. The stone 
also receives the solar beams, is warmed, and transmits 
its heat, by conduction, to the ice beneath it. If the heat 
thus transmitted to the ice through the stone be less than 
an equal space of the surrounding ice receives, it is 
manifest that the ice around the stone will waste more 
quickly than that beneath it, and the consequence is, that, 




MORAINES OF THE MER DE GLACE. 



FIG. 19. 



To face p. 264 . 



GLACIER TABLES ACCOUNTED FOE, 265 

as the surface sinks, it leaves behind it a pillar of ice, on 
which the block is elevated. If the stone be wide and flat, 
it may rise to a considerable height, and in this position it 
constitutes what is called a glacier-table. (See Fig. 6.) 

Almost all glaciers present examples of such tables ; but 
no glacier with which I am acquainted exhibits them in 
greater number and perfection than the Unteraar glacier, 
near the Grimsel. Vast masses of granite are thus poised 
aloft on icy pedestals ; but a limit is placed to their exalta- 
tion by the following circumstance. The sun plays 
obliquely upon the table all day ; its southern extremity 
receives more heat than its northern, and the conse- 
quence is, that it dips towards the south. Strictly 
speaking, the plane of the dip rotates a little during 
the day, being a little inclined towards the east in the 
morning, north and south a little after noon, and in- 
clined towards the west in the evening ; so that, theore- 
tically speaking, the block is a sun-dial, showing by 
its position the hour of the day. This rotation is, 
however, too small to be sensible, and hence the dip of the 
stones upon a glacier sufficiently exposed to the sunlight, 
enables us at any time to draw the meridian line along its 
surface. The inclination finally becomes so great that the 
block slips off its pedestal, and begins to form another, 
while the one which it originally occupied speedily dis- 
appears, under the influence of sun and air. Fig. 20 repre- 
sents a typical section of a glacier-table, the sun's rays 
being supposed to fall in the direction of the shading lines. 

Stones of a certain size are always lifted in the way 
described. A considerable portion of the heat which a 
large block receives is wasted by radiation, and by com- 
munication to the air, so that the quantity which reaches 
the ice beneath is trifling. Such a mass is, of course, a 
protector of the ice beneath it. But if the stone be small, 
and dark in colour, it absorbs the heat with avidity, com- 



266 



TYPE "TABLE." 



municates it quickly to the ice with which it is in contact, 
and consequently sinks in the ice. This is also the case 
with bits of dirt and the finer fragments of debris ; they sink 
in the glacier. Sometimes, however, a pretty thick layer 




Fig. 20. 

of sand is washed over the ice from the moraines, or from 
the mountain-sides ; and such sand-layers give birth to 
ice-cones, which .grow to peculiarly grand dimensions on 
the Lower Aar glacier. I say " grow," but the truth, of 
course, is, that the surroundiug ice wastes, while the por- 
tion underneath the sand is so protected that it remains 
as an eminence behind. At first sight, these sand-covered 
cones appear huge heaps of dirt, but on examination they 
are found to be cones of ice, and that the dirt constitutes 
merely a superficial covering. 

Turn we now to the moraines. Protecting, as they do, the 
ice from waste, they rise, as might be expected, in vast ridges 
above the general surface of the glacier. In some cases the 
surrounding mass has been so wasted as to leave the spines 
of ice which support the moraines forty or fifty feet above 
the general level of the glacier. I should think the moraines 



MOKAINES ENGULFED AND DISGOKGED. 267 

of the Mer de Glace about the Tacul rise to this height. 
But lower down, in the neighbourhood of the Echelets, 
these high ridges disappear, and nought remains to mark 
the huge moraine but a strip of dirt, and perhaps a slight 
longitudinal protuberance on the surface of the glacier. 
How have the blocks vanished that once loaded the 
moraines near the Tacul ? They have been swallowed in 
the crevasses which intersect the moraines lower down ; 
and if we could examine the ice at the Echelets we 
should find the engulfed rocks in the body of the glacier. 

Oases occur, wherein moraines, after having been 
engulfed, and hidden for a time, are again entirely 
disgorged by the glacier. Two moraines run along the 
basin of the Talefre, one from the Jardin, the other from 
an adjacent promontory, proceeding parallel to each other 
towards the summit of the great ice-fall. Here the ice is 
riven, and profound chasms are formed, in which the 
blocks and shingle of the moraines disappear. Through- 
out the entire ice-fall the only trace of the moraines is a 
broad dirt-streak, which the eye may follow along the centre 
of the fall, with perhaps here and there a stone which has 
managed to rise from its frozen sepulchre. But the ice 
wastes, and at the base of the fall large masses of stone 
begin to reappear; these become more numerous as we 
descend; the smaller debris also appears, and finally, at 
some distance below the fall, the moraine is completely 
restored, and begins to exercise its protecting influence ; 
it rises upon its ridge of ice, and dominates as before over 
the surface of the glacier. 

The ice under the moraines and sand-cones is of a 
different appearance from that of the surrounding glacier, 
and the principles we have laid down enable us to explain 
the difference. The sun's rays, striking upon the unpro- 
tected surface of the glacier, enter the ice to a considerable 
depth; and the consequence is, that the ice near the 



268 TRANSPARENCY OF ICE UNDER THE MORAINES. 

surface of the glacier is always disintegrated, being cut up 
with minute fissures and cavities, filled with water and air, 
which, for reasons already assigned, cause the glacier, 
when it is clean, to appear white and opaque. The ice 
under the moraines, on the contrary, is usually dark and 
transparent ; I have sometimes seen it as black as pitch, 
the blackness being a proof of its great transparency, 
which prevents the reflection of light from its interior. 

The ice under the moraines cannot be assailed in its 
depths by the solar heat, because this heat becomes 
obscure before it reaches the ice, and as such it lacks 
the power of penetrating the substance. It is also com- 
municated in great part by way of contact instead of by 
radiation. A thin film at the surface of the moraine-ice 
engages all the heat that acts upon it, its deeper portions 
remaining intact and transparent. 



NEVE AND GLACIER. 269 



GLACIER MOTION. 
PRELIMINAEY. 

(9-) 

THOUGH a glacier is really composed of two portions, one 
above and the other below the snow-line, the term glacier 
is usually restricted to the latter, while the French term 
neve is applied to the former. It is manifest that the snow 
which falls upon the glacier proper can contribute nothing 
to its growth or permanence ; for every summer is not only 
competent to abolish the accumulations of the foregoing 
winter, but to do a great deal more. During each summer 
indeed a considerable quantity of the ice below the snow- 
line is reduced to water ; so that, if the waste were not in 
some way supplied, it is manifest that in a few years the 
lower portion of the glacier must entirely disappear. The 
end of the Mer de Glace, for example, could never year 
after year thrust itself into the valley of Chamouni, were 
there not some agency by which its manifest waste is 
made good. This agency is the motion of the glacier. 

To those unacquainted with the fact of their motion, but 
who have stood upon these vast accumulations of ice, and 
noticed their apparent fixity and rigidity, the assertion 
that a glacier moves must appear in the highest degree 
startling and incredible. They would naturally share the 
doubts of a certain professor of Tubingen, who, after a visit 
to the glaciers of Switzerland, went home and wrote a 
book flatly denying the possibility of their motion. But 
reflection comes to the aid of sense, and qualifies first 
impressions. We ask ourselves how is the permanence 
of the glacier secured? How are the moraines to be 



270 HUGI'S MEASUREMENTS. 

accounted for ? Whence come the blocks which we often 
find at the terminus of a glacier, and which we know 
belong to distant mountains ? The necessity of motion to 
produce these results becomes more and more apparent, 
until at length we resort to actual experiment. We take 
two fixed points at opposite sides of the glacier, so that a 
block of stone which rests upon the ice may be in the 
straight line which unites the points ; and we soon find 
that the block quits the line, and is borne downwards by 
the glacier. We may well realize the interest of the man 
who first engaged in this experiment, and the pleasure 
which he felt on finding that the block moved ; for 
even now, after hundreds of observations on the motion 
of glaciers have been made, the actual observance of this 
motion for the first time is always accompanied by a thrill 
of delight. Such pleasure the direct perception of natural 
truth always imparts. Like Antasus we touch our mother, 
and are refreshed by the contact. 

The fact of glacier-motion has been known for an inde- 
finite time to the inhabitants of the mountains ; but the 
first who made quantitative observations of the motion was 
Hugi. He found that from 1827 to 1830 his cabin upon 
the glacier of the Aar had moved 100 metres, or about 110 
yards, downwards ; in 1836 it had moved 714 metres ; and 
in 1841 M. Agassiz found it at a distance of 1,428 metres 
from its first position. This is equivalent in round num- 
bers to an average velocity of 100 metres a year. In 
1840 M. Agassiz fixed the position of the rock known as 
the Hotel des Neufchatelois ; and on the 5th of September, 
1841, he found that it had moved 213 feet downward. 
Between this date and September, 1842, the rock moved 
273 feet, thus accomplishing a distance of 486 feet in two 
years. 

But much uncertainty prevailed regarding the motion 
of the boulders, for they sometimes rolled upon the glacier, 



AGASSIZ'S MEASUREMENTS. 271 

and hence it was resolved to use stakes of wood driven into 
the ice. In the month of July, 1841, M. Escher de la 
Linth fixed a system of stakes, every two of which were 
separated from each other by a distance of 100 metres, 
across the great Aletsch glacier. A considerable number 
of other stakes were fixed along the glacier, the longitu- 
dinal separation being also 100 metres. On the 8th of 
July the stakes stood at a depth of about three feet in 
the ice. On the 16th of August he returned to the glacier. 
Almost all the stakes had fallen, and no trace, even of the 
holes in which they had been sunk, remained. M. Agassiz 
was equally unsuccessful on the glacier of the Aar. It 
must therefore be borne in mind, that, previous to the 
introduction of the facile modes of measurement which we 
now employ, severe labour and frequent disappointment 
had taught observers the true conditions of success. 

After his defeat upon the Aletsch, M. Escher joined 
MM. Agassiz and Desor on the Aar glacier, where, between 
the 31st of August and the 5th of September, they fixed 
in concert the positions of a series of blocks upon the ice, 
with the view of measuring their displacements the follow- 
ing year. 

Another observation of great importance was also com- 
menced in 1841. Warned by previous failures, M. Agassiz 
had iron boring-rods carried up the glacier, with which he 
pierced the ice at six places to a depth of ten feet, and 
at each place drove a wooden pile into the ice. These six 
stations were in the same straight line across the glacier ; 
three of them standing upon the Finsteraar and three on 
the Lauteraar tributary. About this time also M. Agassiz 
conceived the idea of having the displacements measured 
the year following with precise instruments, and also of 
having constructed, by a professional engineer, a map of 
the entire glacier, on which all its visible "accidents" 
should be drawn according to scale. This excellent work 



272 PROF. J. D. FORBES INVITED. 

was afterwards executed by M. Wild, now Professor of 
Geodesy and Topography in the Polytechnic School of 
Zurich, and it is published as a separate atlas in connexion 
with M. Agassiz's ' Systeme Glaciaire.' 

M. Agassiz is a naturalist, and he appears to have de- 
voted but little attention to the study of physics. At all 
events, the physical portions of his writings appear to me 
to be very often defective. It was probably his own con- 
sciousness of this deficiency that led him to invoke the 
advice of Arago and others previous to setting out upon his 
excursions. It was also his desire " to see a philosopher so 
justly celebrated occupy himself with the subject," which 
induced him to invite Prof. J. D. Forbes of Edinburgh to 
be his guest upon the Aar glacier in 1841. On the 8th 
of August they met at the Grimsel Hospice, and for 
three weeks afterwards they were engaged together daily 
upon the ice, sharing at night the shelter of the same 
rude roof. It is in reference to this visit that Prof. Forbes 
writes thus at page 38 of the ' Travels in the Alps ' : " Far 
from being ready to admit, as my sanguine companions 
wished me to do in 1841, that the theory of glaciers was 
complete, and the cause of their motion certain, after pa- 
tiently hearing all they had to say and reserving my opinion, 
I drew the conclusion that no theory which I had then 
heard of could account for the few facts admitted on all 
hands." In 1842 Prof. Forbes repaired, as early as the 
state of the snow permitted, to the Mer de Glace ; he worked 
there, in the first instance, for a week, and afterwards 
crossed over to Courmayeur to witness a solar eclipse. The 
result of his week's observations was immediately commu- 
nicated to Prof. Jameson, then editor of the ' Edinburgh 
New Philosophical Journal.' 

In that letter he announces the fact, but gives no details 
of the measurement, that " the central part of the glacier 
moves faster than the edges in a very considerable proper- 



CENTRE MOVES QUICKEST. 273 

tion ; quite contrary to the opinion generally entertained." 
He also announced at the same time the continuous 
hourly advance of the glacier. This letter bears the date, 
" Courmayeur, Piedmont, 4th July," but it was not pub- 
lished until the month of October following. 

Meanwhile M. Agassiz, in company with M. Wild, re- 
turned to complete his experiment upon the glacier of the 
Aar. On the 20th of July, 1842, the displacements of the 
six piles which he had planted the year before were de- 
termined by means of a theodolite. Of the three upon 
the Finsteraar affluent, that nearest the side had moved 
160 feet, the next 225 feet, while that nearest to the centre 
had moved 269 feet. Of those on the Lauteraar, that 
nearest the side had moved 125 feet, the next 210 feet, 
and that nearest the centre 246 feet. These observations 
were perfectly conclusive as to the quicker motion of the 
centre : they embrace a year's motion ; and the magnitude 
of the displacements, causing errors of inches, which might 
seriously affect small displacements, to vanish, justifies us 
in ranking this experiment with the most satisfactory of 
the kind that have ever been made. The results were 
communicated to Arago in a letter dated from the glacier 
of the Aar, on the 1st of August, 1842 ; they were laid 
before the Academy of Sciences on the 29th of August, 
1842, and are published in the * Comptes Kendus' of 
the same date. 

The facts, then, so far as I have been able to collect 
them, are as follows : M. Agassiz commenced his ex- 
periment about ten months before Professor Forbes, and 
the results of his measurements, with quantities stated, 
were communicated to the French Academy about two 
months prior to the publication of the letter of Professor 
* Forbes in the ' Edinburgh Philosophical Journal.' But 
the latter communication, announcing in general terms 
the fact of the speedier central motion, was dated from 

T 



274 STATE OF THE QUESTION. 

Courmayeur twenty-seven days before the date of M. 
Agassiz's letter from the glacier of the Aar. 

The speedier motion of the central portion of a glacier 
has been justly regarded as one of cardinal importance, 
and no other observation has been the subject of such 
frequent reference ; but the general impression in Eng- 
land is that M. Agassiz had neither part nor lot in the 
establishment of the above fact ; and in no English work 
with which I am acquainted can I find any reference to 
the above measurements. Relying indeed upon such 
sources for my information, I remained ignorant of the 
existence of the paper in the ' Comptes Rendus ' until my 
attention was directed to it by Professor Wheatstone. In 
the next following chapters I shall have to state the results 
of some of my own measurements, and shall afterwards 
devote a little time to the consideration of the cause of 
glacier-motion. In treating a question on which so much 
has been written, it is of course impossible, as it would be 
undesirable, to avoid subjecting both my own views and 
those of others to a critical examination. But in so doing 
I hope that no expression shall escape me inconsistent with 
the courtesy which ought to be habitual among philoso- 
phers or with the frank recognition of the just claims of 
my predecessors. 



MY FIRST OBSERVATION. 275 



MOTION OF THE MER DE GLACE. 

(10.) 

ON Tuesday, the 14th of July, 1857, I made my first 
observation on the motion of the Mer de Glace. Accom- 
panied by Mr. Hirst I selected on the steep slope of the 
Glacier des Bois a straight pinnacle of ice, the front edge 
of which was perfectly vertical. In coincidence with this 
edge I fixed the vertical fibre of the theodolite, and per- 
mitted the instrument to stand for three hours. On 
looking through it at the end of this interval, the cross 
hairs were found projected against the white side of the 
pyramid ; the whole mass having moved several inches 
downwards. 

The instrument here mentioned, which had long been 
in use among engineers and surveyors, was first applied 
to measure glacier-motion in 1842; by Prof. Forbes on 
the Mer de Glace, and by M. Agassiz on the glacier of 
the Aar. The portion of the theodolite made use of 
is easily understood. The instrument is furnished with 
a telescope capable of turning up and down upon a 
pivot, without the slightest deviation right or left ; and 
also capable of turning right or left without the slight- 
est deviation up or down. Within the telescope two 
pieces of spider's thread, so fine as to be scarcely visible 
to the naked eye, are drawn across the tube and across 
each other. When we look through the telescope we 
see these fibres, their point of intersection being exactly 
in the centre of the tube; and the instrument is fur- 
nished with screws by means of which this point can 
be fixed upon any desired object with the utmost preci- 
sion. 

T 2 



276 MODE OF MEASUREMENT. 

In setting a straight row of stakes across the glacier, 
our mode of proceeding was in all cases this : The theo- 
dolite was placed on the mountain-side flanking the 
glacier, quite dear of the ice; and having determined 
the direction of a line perpendicular to the axis of the 
glacier, a well-defined object was sought at the opposite 
side of the valley as close as possible to this direction ; 
the object being, in some cases, the sharp edge of a cliff; 
in others, a projecting corner of rock ; and, in others, a 
well-defined mark on the face of the rock. This object 
and those around it^ were carefully sketched, so that on 
returning to the place it could be instantly recognized. 
On commencing a line the point of intersection of the 
two spiders' threads within the telescope was first fixed 
accurately upon the point thus chosen, and an assistant 
carrying a straight baton was sent upon the ice. By rough 
signalling he first stood near the place where the first 
stake was to be driven in ; and the object end of the tele- 
scope was then lowered until he came within the field of 
view. He held his staff upright upon the ice, and, in 
obedience to signals, moved upwards or downwards until 
the point of intersection of the spiders' threads exactly 
hit the bottom of the baton ; a concerted signal was 
then made, the ice was pierced with an auger to a depth 
of about sixteen inches, and a stake about two feet long 
was firmly driven into it. The assistant then advanced 
for some distance across the glacier; the end of the 
telescope was now gently raised until he and his upright 
staff again appeared in the field of view. He then moved 
as before until the bottom of his staff was struck by the 
point of intersection, and here a second stake was fixed 
in the ice. In this way the process was continued until 
the line of stakes was completed. 

Before quitting the station, a plummet was suspended 
from a hook directly underneath the centre of the theo- 



THE FIRST LINE. 277 

dolite, and the place where the point touched the ground 
was distinctly marked. To measure the motion of the 
line of stakes, we returned to the place a day or two 
afterwards, and by means of the plummet were able to 
make the theodolite occupy the exact position which it 
occupied when the line was set out. The telescope being 
directed upon the point at the opposite side of the valley, 
and gradually lowered, it was found that no single stake 
along the line preserved its first position : they had all 
shifted downwards. The assistant was sent to the first 
stake ; the point which it had first occupied was again 
determined, and its present distance from that point 
accurately measured. The same thing was done in the 
case of each stake, and thus the displacement of the 
whole row of stakes was ascertained.* The time at which 
the stake was fixed, and at which its displacement was 
measured, being carefully noted, a simple calculation de- 
termined the daily motion of the stake. 

Thus, on the 17th of July, 1857, we set out our first 
line across the Mer de Glace, at some distance below the 
Montanvert ; on the day following we measured the pro- 
gress of the stakes. The observed displacements are set 
down in the following table : 

FIRST LINE. DAILY MOTION. 



No. of stake. Inches. 
WEST 1 moved 12 

2 16f 

3 221 
4 



No. of stake. Inches. 

6 moved 

7 26 
8 

9 28f 



5 24| 10 35 EAST. 

* Great care is necessary on the part of the man who measures the dis- 
placements. The staff ought to be placed along the original line, and the 
assistant ought to walk along it until the foot of a perpendicular from the 
stake is attained. When several days' motion is to be measured, this pre- 
caution is absolutely necessary ; the eye being liable to be grossly deceived 
in guessing the direction of a perpendicular. 



278 THE CENTRE-POINT NOT THE QUICKEST. 

The theodolite in this case stood on the Montanvert side 
of the valley, and the stakes are numbered from this side. 
We see that the motion gradually augments from the 1st 
stake onward the 1st stake being held back by the 
friction of the ice against the flanking mountain-side. 
The stakes 4, 6, and 8 have no motion attached to them, 
as an accident rendered the measurement of their displace- 
ments uncertain. But one remarkable fact is exhibited 
by this line ; the 7th stake stood upon the middle of the 
glacier, and we see that its motion is by no means the 
quickest ; it is exceeded in this respect by the stakes 9 
and 10. 

The portion of the glacier on which the 10th stake stood 
was very much cut up by crevasses, and, while the assistant 
was boring it with his auger, the ice beneath him was 
observed, through the telescope, to slide suddenly forward 
for about 4 inches. The other stakes retained their posi- 
tions, so that the movement was purely local. Deducting 
the 4 inches thus irregularly obtained, we should have a 
daily motion of 31-J inches for stake No. 10, The place was 
watched for some time, but the slipping was not repeated ; 
and a second measurement on the succeeding day made 
the motion of the 10th stake 32 inches, whilst that of the 
centre of the glacier was only 27. 

Here, then, was a fact which needed explanation ; but, 
before attempting this, I resolved, by repeated measure- 
ments in the same locality, to place the existence of the 
fact beyond doubt. We therefore ascended to a point 
upon the old and now motionless moraine, a little above 
the Montanvert Hotel ; and choosing, as before, a well- 
defined object at the opposite side of the valley, we set 
between it and the theodolite a row of twenty stakes 
across the glacier. Their motions, measured on a sub- 
sequent day, and reduced to their daily rate, gave the 
results set down in the following table : 



CORROBORATIVE MEASUREMENTS. 279 



SECOND LINE. DAILY MOTION. 



No. of stake. Inches. 

WEST 1 moved 7i 

2 10f 

3 _12J 

4 14| 

5 16 

6 16f 

7 17* 

8 19 

9 19 
10 21 



No. of stake. Inches. 

11 moved 21 

12 22| 

13 21 

14 22| 

15 20i 

16 21f 

17 22 

18 25 
19 

20 25f EAST. 



As regards the retardation of the side, we observe here 
the same fact as that revealed by our first line the 
motion gradually augments from the first stake to the last. 
The stake No. 20 stood upon the dirty portion of the ice, 
which was derived from the Talefre tributary of the Mer 
de Glace, and far beyond the middle of the glacier. 
These measurements, therefore, corroborate that made 
lower down, as regards the non-coincidence of the point 
of swiftest motion with the centre of the glacier. 

But it will be observed that the measurements do not 
show any retardation of the ice at the eastern extremity of 
the line of stakes the motion goes on augmenting from the 
first stake to the last. The reason of this is, that in neither 
of the cases recorded were we able to get the line quite 
across the glacier ; the crevasses and broken ice-ridges, 
which intercepted the vision, compelled us to halt before 
we came sufficiently close to the eastern side to make its 
retardation sensible. But on the 20th of July my friend 
Hirst sought out an elevated station on the Chapeau, or 
eastern side of the valley, whence he could command a 
view from side to side over all the humps and inequalities 
of the ice, the fixed point at the opposite side, upon 
which the telescope was directed, being the corner of a 
window of the Montaiivert Hotel. Along this line were 



280 A NEW PECULIARITY OF GLACIEK MOTION. 

placed twelve stakes, the daily motions of which were 
found to be as follows : 



THIRD LINE. DAILY MOTION. 



No. of stake. 
EAST 1 moved 
2 
3 
4 
5 
6 



Inches. 

22f 
28f 

33f 



No. of stake. 

7 moved 

8 

9 

10 
11 
12 



Inches. 
24| 
25 
25 
18 



8 1 WEST. 



The numbering of the stakes along this line commenced 
from the Chapeau-side of the glacier, and the retardation 
of that side is now manifest enough ; the motion gradually 
augmenting from 19^ to 33^ inches. But, comparing the 
velocity of the two extreme stakes, we find that the retarda- 
tion of stake 12 is much greater than that of stake 1. 
Stake 5, moreover, which moved with the maximum velo- 
city, was not upon the centre of the glacier, but much 
nearer to the eastern than to the western side. 

It was thus placed beyond doubt that the point of maxi- 
mum motion of the Mer de Glace, at the place referred to, 
is not the centre of the glacier. But, to make assurance 
doubly sure, I examined the comparative motion along 
three other lines, and found in all the same undeviating 
result. 

This result is not only unexpected, but is quite at 
variance with the opinions hitherto held regarding the 
motion of the Mer de Glace. The reader knows that the 
trunk-stream is composed of three great tributaries from 
the Geant, the Lechaud, and the Taldfre. The Glacier du 
Geant fills more than half of the trunk-valley, and the 
junction between it and its neighbours is plainly marked 
by the dirt upon the surface of the latter. In fact four 
medial moraines are crowded together on the eastern side 



LAW OF MOTION SOUGHT. 281 

of the glacier, and before reaching the Montanvert they 
have strewn their debris quite over the adjacent ice. 
A distinct limit is thus formed between the clean Glacier 
du Geant and the other dirty tributaries of the trunk- 
stream. 

Now the eastern side of the Mer de Glace is observed 
on the whole to be much more fiercely torn than the 
western side, and this excessive crevassing has been re- 
ferred to the swifter motion of the Glacier du Geant. It 
has been thought that, like a powerful river, this glacier 
drags its more sluggish neighbours after it, and thus tears 
them in the manner observed. But the measurement of 
the foregoing three lines shows that this cannot be the true 
cause of the crevassing. In each case the stakes which 
moved quickest lay upon the dirty portion of the inuiik- 
stream, far to the east of the line of junction of the Glacier 
du Geant, which in fact moved slowest of all. 

The general view of the glacier, and of the shape of the 
valley which it filled, suggested to me that the analogy 
with a river might perhaps make itself good beyond the 
limits hitherto contemplated. The valley was not straight, 
but sinuous. At the Montanvert the convex side of the 
glacier was turned eastward ; at some distance higher up, 
near the passages called Les Fonts, it was turned west- 
ward; and higher up again it was turned once more, 
for a long stretch, eastward. Thus between Trelaporte and 
the Fonts we had what is called a point of contrary flex- 
ure, and between the Fonts and the Montanvert a second 
point of the same kind." 

Supposing a river, instead of the glacier, to sweep 
through this valley ; its point of maximum motion would 
not always remain central, but would deviate towards that 
side of the valley to which the river turned its convex 
boundary. Indeed the positions of towns along the banks 
of a navigable river are mainly determined by this circum- 



282 CONJECTURE REGARDING CHANGE OF FLEXURE. 



stance. They are, in most cases, situate on the convex 
sides of the bends, where the rush of the water prevents 
silting up. Can it be then that the ice exhibits a simi- 
lar deportment ? that the same principle which regulates 
the distribution of people along the banks of the Thames 
is also acting with silent energy amid the glaciers of the 
Alps ? If this be the case, the position of the point of 
maximum motion ought, of course, to shift with the 
bending of the glacier. Opposite the Fonts, for example, 
the point ought to be on the Glacier du Geant, and west- 
ward of the centre of the trunk-stream ; while, higher up, 
we ought to have another change to the eastern side, in 
accordance with the change of flexure. 

On the 25th of July a line was set out across the glacier, 
one of its fixed termini being a mark upon the first of the 
three Fonts. The motion of this line, measured on a sub- 
sequent day, and reduced to its daily rate, was found to 
be as follows : 



FOURTH LINE. DAILY MOTION. 



No. of stake. 
EAST 1 moved 

2 

3 

4 

5 

6 

7 

8 

9 



Inches. 



18 



18f 



No. of stake. 




Inches. 


10 


moved 


21 


11 





20^ 


12 


,, 


23J 


13 





23^ 


14 


M 


21 


15 


J5 


22^ 


16 


,, 


17i 


17 





15 V 



This line, like the third, was set out and numbered from 
the eastern side of the glacier, the theodolite occupying a 
position on the heights of the Echelets. A moment's 
inspection of the table reveals a fact different from that 
observed on the third line ; there the most easterly stake 
moved with more than twice the velocity of the most 



CONJECTURE TESTED. 288 

westerly one ; here, on the contrary, the most westerly 
stake moves with more than twice the velocity of the most 
easterly one. 

To enable me to compare the motion of the eastern and 
western halves of the glacier with greater strictness, my 
able and laborious companion undertook the task of mea- 
suring with a surveyor's chain the line just referred to ; 
noting the pickets which had been fixed along the line, and 
the other remarkable objects which it intersected. The 
difficulty of thus directing a chain over crevasses and 
ridges can hardly be appreciated except by those who 
have tried it. Nevertheless, the task was accomplished, and 
the width of the Mer de Glace, at this portion of its course, 
was found to be 863 yards, or almost exactly half a mile. 

Referring to the last table, it will be seen that the 
two stakes numbered 12 and 13 moved with a common 
velocity of 23 J inches per day, and that their motion is 
swifter than that of any of the others. The point of 
swiftest motion may be taken midway between them, and 
this point was found by measurement to lie 233 yards west 
of the dirt which marked the junction of the Glacier du 
Geant with its fellow tributaries : whereas, in the former 
cases, it lay a considerable distance east of this limit. 
Its distance from the eastern side of the glacier was 
601 yards, and from the western side 262 yards, being 
170 yards west of the centre of the glacier. 

But the measurements enabled me to take the stakes in 
pairs, and to compare the velocity of a number of them 
which stood at certain distances from the eastern side of 
the valley, with an equal number which stood at the same 
distances from the western side. By thus arranging the 
points two by two, I was able to compare the motion of 
the entire body of the ice at the one side of the central 
line with that of the ice at the other side. Stake 17 
stood about as far from the western side of the glacier as 



284 



WESTERN HALF MOVES QUICKEST. 



stake 3 did from its eastern side; 16 occupied the same 
relation to 4 ; 15, to 5 ; 13, to 7 ; and 12, to 9. 

Calling each pair of points which thus stand at equal 
distances from the opposite sides corresponding points, the 
following little table exhibits their comparative motions : 

NUMBERS AND VELOCITIES OF CORRESPONDING POINTS 
ON THE FOURTH LINE. 

No. Vel. No. Vel. No. Vel. No. Vel. No. Vel. 

West... 17 15 16 17 J 15 22J 13 23| 12 23 

East... 3 12 4 15 5 15f 7 18J 9 19 

The table explains itself. We see that while stake 17, 
which stands west of the centre, moves 15 inches, stake 3, 
which stands an equal distance east of the centre, moves 
only 12J inches. Comparing every pair of the other points, 
we find the same to hold good ; the western stake moves 
in each case faster than the corresponding eastern one. 
Hence, the entire western half of the Her de Glace, at the 
place crossed by our fourth line, moves more quickly than the 
eastern half of the glacier. 

We next proceeded farther up, and tested the contrary 
curvature of the glacier, opposite to Trelaporte. The 
station chosen for this purpose was on a grassy platform 
of the promontory, whence, on the 28th of July, a row of 
stakes was fixed at right angles to the axis of the glacier. 
Their motions, measured on the 31st, gave the following 
results : 

FIFTH LINE.* DAILY MOTION. 

No. of stake. 
WEST 1 moved 
2 
3 
4 
5 
6 
7 
8 

* The details of the measurement of the fourth and fifth lines are 
published in the 'Philosophical Transactions,' vol. cxlix., p. 261. 



nches. 


No. of stake. 


Inches. 


n? 


9 moved 


19f 


134 


10 


19 


12f 


H 


19| 


15 


12 


17! 


15* 


13 


16 


16 


14 


14f 


17| 


15 


10 E 



EASTERN HALF MOVES QUICKEST. 

285 

This line was set out and numbered from the Trelaporte 
side of the valley, and was also measured by Mr. Hirst, 
over boulders, ice-ridges, chasms, and moraines. The entire 
width of the glacier here was found to be 893 yards, or 
somewhat wider than it is at the Fonts. It will also be 
observed that its motion is somewhat slower. 

An inspection of the notes of this line showed me that 
stakes 3 and 14, 4 and 12, 7 and 10, were "correspond- 
ing points " ; the first of each pair standing as far from the 
western side, as the second stood from the eastern. In 
the following table these points and their velocities are 
arranged exactly as in the case of the fourth line. 

NUMBERS AND VELOCITIES OF THE CORRESPONDING POINTS 
ON THE FIFTH LINE. 

No. Vel. No. Vel. No. Vel. 

West ... 3 12f 4 15 7 17 

East ... 14 14f 12 m 10 19 

In each case we find that the stake on the eastern side 
moves more quickly than the corresponding one upon the 
western side : so that where the fifth line crosses the glacier 
the eastern half of the Mer de Glace moves more quickly than 
the western half. This is the reverse of the result obtained 
at our fourth line, but it agrees with that obtained on our 
first three lines, where the curvature of the valley is 
similar. The analogy between a river and a glacier 
moving through a sinuous valley is therefore complete. 

Supposing the points of maximum motion to be deter- 
mined for a great number of lines across the glacier, the 
line uniting all these points is what mathematicians would 
call the locus of the point of maximum motion. At Trela- 
porte this line would lie east of the centre ; at the Fonts 
it would lie west of the centre ; hence, in passing from 
Trelaporte to the Fonts, it must cross the axis of the 
glacier. Again, at the Montanvert, it would lie east of the 



286 



LOCUS OF POINT OF SWIFTEST MOTION. 



centre, and between the Fonts and the Montanvert the 
axis of the glacier would be crossed a second time. Sup- 
posing the dotted line in Fig. 21 to represent the middle 




Fig. 21. 

line of the glacier, then the defined line would represent 
the locus of the point of maximum motion. It is a curve 
more deeply sinuous than tlie valley itself, and it crosses the 
axis of the glacier at each point of contrary flexure. 

To complete our knowledge of the motion of the Mer 
de Glace, we afterwards determined the velocity of its two 
accessible tributaries the Glacier du Geant, and the 
Glacier de Lechaud. On the 29th of July, a line of stakes 
was set out across the former, a little above the Tacul, 
and their motion was subsequently found to be as follows : 
SIXTH LINE. DAILY MOTION. 



No. of stake. Inches. 

1 moved 11 

2 10 

3 12 

4 13 

5 12 



No. of stake. Inches. 

6 moved . 12| 

7 10| 

8 10 

9 9 
10 5 



The width of the glacier at this place we found to be 1 134 
yards, and its maximum velocity, as shown by the fore- 
going table, 13 inches a day. 

On the 1st of August a line was set out across the 
Glacier de Lechaud, above its junction with the Talefre : 
it commenced beneath the block of stone known as the 
Pierre de Beranger. The displacements of the stakes, 
measured on the 3rd of August, gave the following 
results : 



SQUEEZING AT TEELAPORTE. 287 

SEVENTH LINE. DAILY MOTION. 

No. of stake. Inches. No. of stake. Inches. 



1 moved 4| 

2 8| 

3 94 

4 9 

5 8i 



6 moved 



10 



The width of the Glacier de Lechaud at this place was 
found to be 825 yards ; its maximum motion, as shown by 
the table, being 9J inches a day. This is the slowest rate 
which we observed upon either the Mer de Glace or its 
tributaries. The width of the Talefre-branch, as it descends 
the cascade, or, in other words, before it is influenced by 
the pressure of the Lechaud, was found approximately to 
be 638 yards. 

The widths of the tributaries were determined for the 
purpose of ascertaining the amount of lateral compres- 
sion endured by the ice in its passage through the neck 
of the valley at Trelaporte. Adding all together we 
have 

Geant 1134 yards. 

Lechaud 825 

Talefre* 638 

Total 2597 yards. 

These three branches, as shown by the actual measurement 
of our 5th line, are forced at Trelaporte through a channel 
893 yards wide ; the width of the trunk stream is a little 
better than one-third of that of its tributaries, and it passes 
through this gorge at a velocity of nearly 20 inches a day. 
Limiting our view to one of the tributaries only, the 
result is still more impressive. Previous to its junction 
with the Talefre, the Glacier de Lechaud stretches before 
the observer as a broad river of ice, measuring 825 yards 
across : at Trelaporte it is squeezed, in a frozen vice, 
between the Talefre on one side and the Geant on the 



288 THE LECHAUD A DEIBLET. 

other, to a driblet, measuring 85 yards in width, or about 
one-tenth of its former transverse dimension. It will of 
course be understood that it is the form and not the volume 
of the glacier that is affected to this enormous extent 
by the pressure. 

Supposing no waste took place, the Glacier de Lechaud 
would force precisely the same amount of ice through the 
"narrows" at Trelaporte, in one day, as it sends past the 
Pierre de Beranger. At the latter place its velocity is 
about half of what it is at the former, but its width is more 
than nine times as great. Hence, if no waste took place, 
its depth, at Trelaporte, would be at least 4^ times its depth 
opposite the Pierre de Beranger. Superficial and sub- 
glacial melting greatly modify this result. Still I think it 
extremely probable that observations directed to this end 
would prove the comparative shallowness of the upper 
portions of the Glacier de Lechaud. 



FIEST ATTEMPT AT MEASUREMENT. 289 

ICE-WALL AT THE TACUL. 

VELOCITIES OF TOP AND BOTTOM. 

(11.) 

As regards the motion of the surface of a glacier, two laws 
are to be borne in mind : 1st, that regarding the quicker 
movement of the centre ; 2nd, that regarding the locus 
of the point of maximum motion. Our next care must 
be to compare the motion of the surface of a glacier 
with the motion of those parts which lie near its bed. 
Rendu first surmised that the bottom of the glacier was 
retarded by friction, and both Professor Forbes * and M. 
Martins f have confirmed the conjecture. Theirs are the 
only observations which we possess upon the subject ; and 
I was particularly desirous to instruct myself upon this 
important head by measurements of my own. 

During the summer of 1857 the eastern side of the 
Glacier du Geant, near the Tacul, exposed a nearly ver- 
tical precipice of ice, measuring 140 feet from top to 
bottom. I requested Mr. Hirst to fix two stakes in the 
same vertical plane, one at the top of the precipice 
and one near the bottom. This he did upon the 3rd of 
August, and on the 5th I accompanied him to measure 
the progress of the stakes. On the summit of the pre- 
cipice, and running along it, was the lateral moraine of 
the glacier. The day was warm and the ice liquefying 
rapidly, so that the boulders and debris, deprived inces- 
santly of their support, came in frequent leaps and rushes 
down the precipice. Into this peril my guide was about 

* ' Edinb. Phil. Journ.,' Oct. 1846, p. 417. 
t Agassiz, ' Syst^me Glaciaire,' p. 522. 

U 



290 STAKES FIXED AT TOP, BOTTOM, AND CENTRE. 

to enter, to measure the displacement of the lower 
stake, while I was to watch, and call out the direction in 
which he was to run when a stone gave way. But I soon 
found that the initial motion was no sure index of the final 
motion. By striking the precipice, the stones were often 
deflected, and carried wide of their original direction. I 
therefore stopped the man, and sent him to the summit ot 
the precipice to remove all the more dangerous blocks. 
This accomplished, he descended, and while I stood beside 
him, executed the required measurement. From the 3rd 
to the 5th of August the upper stake had moved twelve 
inches, and the lower one six. 

Unfortunately some uncertainty attached itself to this 
result, due to the difficulty of fixing the lower stake. 
The guide's attention had been divided between his work 
and his safety, and he had to retreat more than a dozen 
times from the falling boulders and debris. I, on the other 
hand, was unwilling to accept an observation of such im- 
portance with a shade of doubt attached to it. Hence arose 
the desire to measure the motion myself. On the llth of 
August I therefore reascended to the Tacul, and fixed a 
stake at the top of the precipice, and another at the 
bottom. While sitting on the old moraine looking at the 
two pickets, the importance of determining the motion 
of a point midway between the top and bottom forcibly 
occurred to me, but, on mentioning it to my guide, he 
promptly pronounced any attempt of the kind absurd. 

On scanning the place carefully, however, the value of 
the observation appeared to me to outweigh the amount of 
danger. I therefore took my axe, placed a stake and an 
auger against my breast, buttoned my coat upon them, 
and cut an oblique staircase up the wall of ice, until I 
reached a height of forty feet from the bottom. Here the 
position of the stake being determined by Mr. Hirst, who 
was at the theodolite, I pierced the ice with the auger, 



THROUGH GLOOM TO THE TACUL. 291 

drove in the stake, and descended without injury. During 
the whole operation however my guide growled audibly. 

On the following morning we commenced the ascent of 
Mont Blanc, a narrative of which is given in Part I. 
We calculated on an absence of three days, and estimated 
that the stakes which had just been fixed would be ready 
for measurement on our return ; but we did not reach 
Chamouni until the afternoon of Friday, the 14th. Heavy 
clouds settled, during our descent, upon the summits 
behind us, and a thunder-peal from the Aiguilles soon 
heralded a fall of rain, which continued without inter- 
mission till the afternoon of the 16th, when the atmo- 
sphere cleared, and showed the mountains clothed to their 
girdles with snow. The Montanvert was thickly covered, 
and on our way to it we met the servants in charge of 
the cattle, which had been driven below the snow-line to 
obtain food. 

On Monday morning, the 17th, a dense fog filled the 
valley of the Mer de Glace. I watched it anxiously. The 
stakes which we had set at the Tacul had been often 
in my thoughts, and I wished to make some effort to 
save the labour and peril incurred in setting them 
from being lost. I therefore set out, in one of the clear 
intervals, accompanied by my friend and Simond, deter- 
mined to measure the motion of the stakes, if possible, 
or to fix them more firmly, if they still stood. As we 
passed, however, from 1'Angle to the glacier, the fog 
became so dense and blinding that we halted. At my re- 
quest Mr. Hirst returned to the Montanvert ; and Simond, 
leaving the theodolite in the shelter of a rock, accom- 
panied me through the obscurity to the Tacul. We found 
the topmost stake still stuck by its point in the ice ; but 
'the two others had disappeared, and we afterwards dis- 
covered their fragments in a snow-buttress, which reared 
itself against the base of the precipice. They had been 

u 2 



292 DESCENT OF BOULDERS. 

hit by the falling stones, and crushed to pieces. Having 
thus learned the worst, we descended to the Montanvert 
amid drenching rain. 

On the morning of the 18th there was no cloud to 
be seen anywhere, and the sunlight glistened brightly on 
the surface of the ice. We ascended to the Tacul. The 
spontaneous falling of the stones appeared more frequent 
this morning than I had ever seen it. The sun shone 
with unmitigated power upon the ice, producing copious 
liquefaction. The rustle of falling debris was incessant, 
and at frequent intervals the boulders leaped down the 
precipice, and rattled with startling energy amid the rocks 
at its base. I sent Simond to the top to remove the looser 
stones ; he soon appeared, and urged the moraine -shingle 
in showers down the precipice, upon a bevelled slope of 
which some blocks long continued to rest. They were 
out of the reach of the guide's baton, and he sought to 
dislodge them by sending other stones down upon them. 
Some of them soon gave way, drawing a train of smaller 
shingle after them ; others required to be hit many times 
before they yielded, and others refused to be dislodged 
at all. I then cut my way up the precipice in the manner 
already described, fixed the stake, and descended as 
speedily as possible. We afterwards fixed the bottom 
stake, and on the 20th the displacements of all three were 
measured.* The spaces passed over by the respective 
stakes in 24 hours were found to be as follows : 

Inches. 

Top stake 6-00 

Middle stake 4-50 

Bottom stake 2-56 

The height of the precipice was 140-8 feet, but it sloped 
off at its upper portion. The height of the middle 

* On this latter occasion my guide volunteered to cut the steps for me 
up to the pickets ; and I permitted him to do so. In fact, he was at last 
as anxious as myself to see the measurement carried out. 



MOTION OF STAKES. 293 

stake above the ground was 35 feet, and of the bottom 
one 4 feet. It is therefore proved by these measurements 
that the bottom of the ice-wall at the Tacul moves with 
less than half the velocity of the top ; while the displace- 
ment of the intermediate stake shows how the velocity 
gradually increases from the bottom upwards. 



294 HALF OF SUMMER MOTION. 



WINTER MOTION OF THE MER DE GLACE. 

(12.) 

THE winter measurements were executed in the manner 
already described, on the 28th and 29th of December, 
1859. The theodolite was placed on the mountain's 
side flanking the glacier, and a well-defined object was 
chosen at the opposite side of the valley, so that a 
straight line between this object and the theodolite was 
approximately perpendicular to the axis of the glacier. 
Fixing the telescope in the first instance with its cross hairs 
upon the object, its end was lowered until it struck the 
point upon the glacier at which a stake was to be fixed. 
Thanks to the intelligence of my assistants, after the fixing 
of the first stake they speedily took up the line at all 
other points, requiring very little correction to make their 
positions perfectly accurate. On the day following that 
on which the stakes were driven in, the theodolite was 
placed in the same position, and the distances to which the 
stakes had moved from their original positions were accu- 
rately determined. As already stated, the first line crossed 
the glacier about 80 yards above the Montanvert Hotel. 

LINE No. I. WINTER MOTION IN TWENTY-FOUR HOURS. 



No. of stake. 


Inches. 


No. of stake. 


Inches. 


WEST 1 


7i 


7 


15f 


2 


11 


8 


15f 


3 


13! 


9 


12* 


4 


13 


10 


12 


5 


13f 


11 


6| EAST. 


6 


14* 







The maximum here is fifteen and three-quarters inches ; 
the maximum summer motion of the same portion of the 



THE SAME LAW IN SUMMER AND WTNTEK. 295 

glacier is about thirty inches. These measurements also 
show that in winter, as well as in summer, the side of the 
glacier opposite to the Montanvert moves quicker than 
that adjacent to it. The stake which moved with the maxi- 
mum velocity was beyond the moraine of La Noire. The 
second line crossed the glacier about 130 yards below the 
Montanvert. 

LINE No. II. WINTER MOTION IN TWENTY-FOUR HOURS. 



No. of stake. 


Inches. 


No. of stake. 


Inches. 


1 


7f 


6 


15f 


2 


9* 


7 




3 


13f 


8 


ief 


4 


16 


9 




5 


16 


10 


14 3 



The maximum here is an inch and three-quarters greater 
than that of line No. 1. The summer maximum at this 
portion of the glacier also exceeds that of the part inter- 
sected by line No. 1. The surface of the glacier between 
the two lines is in a state of tension which relieves itself 
by a system of transverse fissures, and thus permits of the 
quicker advance of the forward portion. 

My desire, in making these measurements, was, in the 
first place, to raise the winter observations of the motion to 
the same degree of accuracy as that already possessed by 
the summer ones. Auguste Balmat had already made a 
series of winter observations on the Mer de Glace ; but 
they were made in the way employed before the intro- 
duction of the theodolite by Agassiz and Forbes, and 
shared the unavoidable roughness of such a mode of mea- 
surement. They moreover gave us no information as to 
the motion of the different parts of the glacier along the 
same transverse line, and this, for reasons which will 
appear subsequently, was the point of chief interest to me. 



296 THE GLACIER SLIDES. 

CAUSE OF GLACIER-MOTIOK 

DE SAUSSURE'S THEORY. 

(13.) 

PERHAPS the first attempt at forming a glacier-theory is 
that of Scheuchzer in 1705. He supposed the motion to 
be caused by the conversion of water into ice within the 
glacier ; the known and almost irresistible expansion which 
takes place on freezing, furnishing the force which pushed 
the glacier downward. This idea was illustrated and deve- 
loped with so much skill by M. de Charpentier, that his 
name has been associated with it ; and it is commonly 
known as the Theory of Charpentier, or the Dilatation- 
Theory. M. Agassiz supported this theory for a time, but 
his own thermometric experiments show us that the body 
of the glacier is at a temperature of 32 Fahr. ; that conse- 
quently there is no interior magazine of cold to freeze the 
water with which the glacier is supposed to be incessantly 
saturated. So that these experiments alone, if no other 
grounds existed, would prove the insufficiency of the theory 
of dilatation. I may however add, that the arguments most 
frequently urged against this theory deal with an assump- 
tion, which I do not think its author ever intended to 
make. 

Another early surmise was that of Altmann and Gruner 
(1760), both of whom conjectured that the glacier slid 
along its bed. This theory received distinct expression 
from De Saussure in 1799 ; and has since been associated 
with the name of that great alpine traveller, being usually 
called the ' Theory of Saussure,' and sometimes the ' Slid- 
ing Theory.' It is briefly stated in these words : 



STRAINED INTERPRETATION. 297 

" Almost every glacier reposes upon an inclined bed, 
and those of any considerable size have beneath them, 
even in winter, currents of water which flow between the 
ice and the bed which supports it. It may therefore be 
understood that these frozen masses, drawn down the slope 
on which they repose, disengaged by the water from all 
adhesion to the bottom, sometimes even raised by this 
water, must glide by little and little, and descend, follow- 
ing the inclinations of the valleys, or of the slopes which 
they cover. It is this slow but continual sliding of the 
ice on its inclined base which carries it into the lower 
valleys." * 

De Saussure devoted but little time to the subject of 
glacier-motion ; and the absence of completeness in the 
statement of his views, arising no doubt from this cause, 
has given subsequent writers occasion to affix what I cannot 
help thinking a strained interpretation to the sliding theory. 
It is alleged that he regarded a glacier as a perfectly rigid 
body; that he considered it to be " a mass of ice of small 
depth, and considerable but uniform breadth, sliding down 
a uniform valley, or pouring from a narrow valley into a 
wider one." f The introduction " of the smallest flexi- 
bility or plasticity" is moreover emphatically denied to 
him. J 

It is by no means probable that the great author of the 
' Voyages ' would have subscribed to this "rigid" annota- 
tion. His theory, be it remembered, is to some extent 
true : the glacier moves over its bed in the manner sup- 
posed, and the rocks of Britain bear to this day the traces 
of these mighty sliders. De Saussure probably contented 
himself with a general statement of what he believed to 

* 'Voyages,' 535. 

f James D. Forbes, ' Occasional Papers on the Theory of Glaciers,' 
1859, p. 100. 

t "I adhere to the definition as excluding the introduction of the 
smallest flexibility or plasticity." ' Occ. Pap.,' p. 96. 



298 GLACIER OF MONT DOLENT. 

be the substantial cause of the motion. He visited the 
Jardin, and saw the tributaries of the Mer de Glace turning 
round corners, welding themselves together, and after- 
wards moving through a sinuous trunk- valley ; and it is 
scarcely credible that in the presence of such facts he 
would have denied all flexibility to the glacier. 

The statement that he regarded a glacier to be a mass 
of ice of uniform width, is moreover plainly inconsistent 
with the following description of the glacier of Mont Dolent : 
" Its most elevated plateau is a great circus, surrounded 
by high cliffs of granite, of pyramidal forms ; thence the 
glacier descends through a gorge, in which it is narrowed ; 
but after having passed the gorge, it enlarges again, 
spreading out like a fan. Thus it has on the whole the 
form of a sheaf tied in the middle and dilated at its two 
extremities." * 

Curiously enough this very glacier, and these very 
words, are selected by M. Rendu as illustrative of the 
plasticity of glaciers. " Nothing," he says, " shows better 
the extent to which a glacier moulds itself to its locality 
than the form of the glacier of Mont Dolent in the Valley 
of Ferret ; " and he adds, in connexion with the same 
passage, these remarkable words : " There is a multitude 
of facts which would seem to necessitate the belief that 
the substance of glaciers enjoys a kind of ductility which 
permits it to mould itself to the locality which it occupies, 
to grow thin, to swell, and to narrow itself like a soft 
paste." f 

* ' Voyages,' tome ii. p. 290. 

f In connexion with this brief sketch of the ' Sliding Theory,' it ought 
to be stated, that Mr. Hopkins has proved experimentally, that ice may 
descend an incline at a sensibly uniform rate, and that the velocity is 
augmented by increasing the weight. In this remarkable experiment the 
motion was due to the slow disintegration of the lower surface of the ice. 
See ' Phil. Mag.,' 1845, vol. 26. 



EENDU'S CHAEACTER. 299 

RENDU'S THEORY. 

(14.) 

M..RENDU, Bishop of Annecy, to whose writings I have 
just referred, died last autumn.* He was a man of great 
repute in his diocese, and we owe to him one of the most 
remarkable essays upon glaciers that have ever appeared. 
His knowledge was extensive, his reasoning close and 
accurate, and his faculty of observation extraordinary. 
With these were associated that intuitive power, that 
presentiment concerning things as yet untouched by ex- 
periment, which belong only to the higher class of minds. 
Throughout his essay a constant effort after quantitative 
accuracy reveals itself. He collects observations, makes 
experiments, and tries to obtain numerical results ; always 
taking care, however, so to state his premises and qualify 
his conclusions that nobody shall be led to ascribe to his 
numbers a greater accuracy than they merit. It is im- 
possible to read his work, and not feel that he was a man 
of essentially truthful mind, and that science missed an 
ornament when he was appropriated by the Church. 

The essay above referred to is printed in the tenth 
volume of the Memoirs of the Royal Academy of Sciences 
of Savoy, published in 1841, and is entitled, c Theorie des 
Glaciers de la Savoie, par M. le Ghanoine Rendu, Chevalier 
du Merite Civil el Secretaire perpetueV The paper had 
been written for nearly two years, and might have re- 
mained unprinted, had not another publication on the 
same subject called it forth. 

I will place a few of the leading points of this remark- 

* [Expressions such as " last summer," " last autumn," " recently," 
will be taken throughout in the sense which they had in the early half 
of 1860, when this book was first published. L. C. T.] 



300 "THEORIE DES GLACIERS DE LA SAVOIE." 

able production before the reader ; commencing with a 
generalization which is highly suggestive of the character 
of the author's mind. 

He reflects on the accumulation of the mountain-snows, 
each year adding fifty-eight inches of ice to a glacier. 
This would make Mont Blanc four hundred feefc higher in 
a century, and four thousand feet higher in a thousand 
years. " It is evident," he says, " that nothing like this 
occurs in nature." The escape of the ice then leads him 
to make some general remarks on what he calls the " law 
of circulation." " The conserving will of the Creator has. 
employed for the permanence of His work the great law 
of circulation, which, strictly examined, is found to repro- 
duce itself in all parts of nature. The waters circulate 
from the ocean to the air, from the air to the earth, 
and from the earth to the ocean. . . . The elements of 
organic substances circulate, passing from the solid to 
the liquid or aeriform condition, and thence again to 
the state of solidity or of organisation. That universal 
agent which we designate by the names of fire, light, 
electricity, and magnetism, has probably also a circula- 
tion as wide as the universe." The italics here are 
Eendu's own. This was published in 1841, but written, 
we are informed, nearly two years before. In 1842 
Mr. Grove wrote thus : " Light, heat, magnetism, motion, 
and chemical affinity, are all convertible material affec- 
tions." More recently Helmholtz, speaking of the " cir- 
cuit " formed by " heat, light, electricity, magnetism, and 
chemical affinity," writes thus : " Starting from each of 
these different manifestations of natural forces, we can 
set every other in action." I quote these passages be- 
cause they refer to the same agents as those named by 
M. Rendu, and to which he ascribes " circulation." Can it 
be doubted that this Savoyard priest had a premonition 
of the Conservation of Force ? I do not want to lay more 



GLACISES EIGHTLY DIVIDED. 301 

stress than it deserves upon a conjecture of this kind ; but its 
harmony with an essay remarkable for its originality gives 
it a significance which, if isolated, it might not possess. 

With regard to the glaciers, Rendu commences by dividing 
them into two kinds, or rather the selfsame glacier into 
two parts, one of which he calls the " glacier reservoir" 
the other the " glacier d'ecoulement" two terms highly 
suggestive of the physical relationship of the neve and 
the glacier proper. He feeds the reservoirs from three 
sources, the principal one of which is the snow, to which he 
adds the rain, and the vapours which are condensed upon 
the heights without passing into the state of either rain or 
snow. The conversion of the snow into ice he supposes 
to be effected by four different causes, the most efficacious 
of which is pressure* It is needless to remark that this 
quite agrees with the views now generally entertained. 

In page 60 of the volume referred to there is a passage 
which shows that the " veined structure " of the glacier 
had not escaped him, though it would seem that he as- 
cribed it to stratification. " When," he writes, " we per- 
ceive the profile of a glacier on the walls of a crevasse, we 
see different layers distinct in colour, but more particularly 
in density ; some seem to have the hardness, as they 
have the greenish colour, of glass; others preserve the 
whiteness and porosity of the snow." There is also a very 
close resemblance between his views of the influence of 
" time and cohesion " and those of Prof. Forbes. " We may 
conclude," he writes, " that time, favouring the action of 
affinity, and the pressure of the layers one upon the other, 
causes the little crystals of which snow is composed to 
approach each other, bring them into contact, and convert 
them into ice." f Regelation also appears to have attracted 
his notice.! " When we fill an ice-house," he writes, " we 
break the ice into very small fragments ; afterwards we wet 
* Memoir,' p. 77. t P- 75. J P. 71. 



302 OBSERVATIONS AND HYPOTHESES. 

it with water 8 or 10 degrees above zero (Cent.) in tempera- 
ture; but, notwithstanding this, the whole is converted into 
a compact mass of ice." He moreover maintains, in almost 
the same language as Prof. Forbes,* the opinion, that ice 
has always an inner temperature lower than zero (Cent. ). 
He believed this to be a property "inherent to ice." 
" Never," he says, " can a calorific ray pass the first surface 
of ice to raise the temperature of the interior." f 

He notices the direction bf the glacier as influencing 
the wasting of its ridges by the sun's heat ; ascribing to it 
the effect to which I have referred in explaining the wave- 
like forms upon the surface of the Mer de Glace. His 
explanation of the Moulins, too, though insufficient, assigns 
a true cause, and is an excellent specimen of physical 
reasoning. 

With regard to the diminution of the glaciers reservoirs, 
or, in other words, to the manner in which the ice dis- 
appears, notwithstanding the continual additions made 
to it, we have the following remarkable passage : " In 
seeking the cause of the diminution of glaciers, it has 
occurred to my mind that the ice, notwithstanding its hard- 
ness and its rigidity, can only support a given pressure 
without breaking or being squeezed out. According to this 
supposition, whenever the pressure exceeds that force, there 
will be rupture of the ice, and a flow in consequence. Let 
us take, at the summit of Mont Blanc, a column of ice 
reposing on a horizontal base. The ice which forms the 
first layer of that column is compressed by the weight of 
all the layers above it ; but if the solidity of the said first 
layer can only support a weight equal to 100, when the 
weight exceeds this amount there will be rupture and 
spreading out of the ice of the base. Now, something very 
similar occurs in the immense crust of ice which covers the 
summits of Mont Blanc. This crust appears to augment at 
* Philosophical Magazine ' 1859 f ' Memoir,' p. 69. 



MEASUEEMENT OF MOTION. 303 

the upper surface and to diminish by the sides. To assure 
oneself that the movement is due to the force of pressure, 
it would be necessary to make a series of experiments upon 
the solidity of ice, such as have not yet been attempted." * 
I may remark that such experiments substantially verify 
M. Eendu's notion. 

But it is his observations and reasoning upon the glaciers 
d'ecoulement that chiefly interest us. The passages in 
his writings where he insists upon the power of the 
glaciers to mould themselves to their localities, and com- 
pares them to a soft paste, to lava at once ductile and 
liquid, are well known from the frequent and nattering 
references of Professor Forbes ; but there are others of 
much greater importance, which have hitherto remained 
unknown in this country. Regarding the motion of the 
Mer de Glace, Rendu writes as follows : 

" I sought to appreciate the quantity of its motion ; but 
I could only collect rather vague data. I questioned my 
guides regarding the position of an enormous rock at the 
edge of the glacier, but still upon the ice, and conse- 
quently partaking of its motion. The guides showed 
me the place where it stood the preceding year, and 
where it had stood two, three, four, and five years pre- 
viously ; they showed me the place where it would be 
found in a year, in two years, &c. ; so certain are they 
of the regularity of the motion. Their reports, however, 
did not always agree precisely with each other, and their 
indications of time and distance lack the precision without 
which we proceed obscurely in the physical sciences. In 
reducing these different indications to a mean, I found 
the total advance of the glacier to be about 40 feet 
a year. During my last journey I obtained more certain 
data, which I have stated in the preceding chapter. The 
enormous difference between the two results arises from the 
* Page 80. 



304 THE SIDES OF THE GLACIER RETARDED. 

fact that the latter observations were made at the centre of 
the glacier, WHICH MOVES MORE RAPIDLY, while the former 
were made at the side, where the ice is RETAINED BY THE 

FRICTION AGAINST ITS ROCKY WALLS." * 

An opinion, founded on a grave misapprehension which 
Eendu enables us to correct, is now prevalent in this 
country, not only among the general public, but also 
among those of the first rank in science. The nature of 
the mistake will be immediately apparent. At page 128 of 
the i Travels in the Alps ' its distinguished author gives a 
sketch of the state of our knowledge of glacier-motion pre- 
vious to the commencement of his inquiries. He cites 
Ebel, Hugi, Agassiz, Bakewell, De la Beche, Shirwell, 
Rendu, and places them in open contradiction to each 
other. Kendu, he says, gives the motion of the Mer de 
Glace to be " 242 feet per annum ; 442 feet per annum ; a 
foot a day ; 400 feet per annum, and 40 feet per annum, 
or one-tenth of the last !".... and he adds, " I was not 
therefore wrong in supposing that the actual progress of a 
glacier was yet a new problem when I commenced my ob- 
servations on the Mer de Glace in 1842. "f 

In the 'North British Review' for August, 1859, a 
writer equally celebrated for the brilliancy of his dis- 
coveries and the vigour of his pen, collected the data 
furnished by the above paragraph into a table, which 
he introduced to his readers in the following words : 
" It is to Professor Forbes alone that we owe the first and 
most correct researches respecting the motion of glaciers ; 
and in proof of this, we have only to give the following 
list of observations which had been previously made. 

* Page 95. 

f At page 38 of the ' Travels ' the following passage also occurs : " I 
believe that I may safely affirm that not one observation of the rate of 
motion of a glacier, either on the average or at any particular season of 
the year, existed when I commenced my experiments in 1842." 



DISCREPANCIES EXPLAINED. 305 

Observers. Name of glacier. Annual rate of motion. 

Ebel Chamouni 14 feet 

Ebel Grindelwald 25 

Hugi Aar 240 

Agassiz Aar 200 

Bakewell Mer de Glace 540 

DelaBeche Mer de Glace 600 

Shirwell Mer de Glace 300 

M. Kendu Mer de Glace 365 

Saussure's Ladder ... Mer de Glace :.. ... ... 375 

. . . Such was the state of our knowledge when Professor 
Forbes undertook the investigation of the subject." 

I am persuaded that the writer of this article will be 
the first to applaud any attempt to remove an error which, 
advanced on his great authority, must necessarily be 
widely disseminated. The numbers in the above table 
certainly differ widely, and it is perhaps natural to con- 
clude that such discordant results can be of no value ; but 
the fact really is that every one of them may be perfectly 
correct. This fact, though overlooked by Professor Forbes, 
was clearly seen by Rendu, who pointed out with perfect 
distinctness the sources from which the discrepancies were 
derived. 

" It is easy," he says, " to comprehend that it is impos- 
sible to obtain a general measure, that there ought to be 
one for each particular glacier. The nature of the slope, 
the number of changes to which it is subjected, the depth 
of the ice, the width of the couloir, the form of its sides, and 
a thousand other circumstances, must produce variations 
in the velocity of the glacier, and these circumstances 
cannot be everywhere absolutely the same. Much more, it 
is not easy to obtain this velocity for a single glacier, and 
for this reason. In those portions where the inclination is 
steep, the layer of ice is thin, and its velocity is great ; in 
those where the slope is almost nothing, the glacier swells 
and accumulates ; the mass in motion being double, triple, 
&c., the motion is only the half, the third, &c. 

x 



806 LIQUID MOTION ASCEIBED TO GLACIER. 

" But this is not all," adds M. Rendu : " Between the Her 
de Glace and a river, there is a resemblance so complete that 
it is impossible to find in the latter a circumstance which does 
not exist in the former. In currents of water the motion is 
not uniform, neither throughout their width nor throughout 
their depth; the friction of the bottom, that of the sides, 
the action of obstacles, cause the motion to vary, and only 
towards the middle of the surface is this entire . . . ." * 

In 1845 Professor Forbes appears to have come to the 
same conclusion as M. Rendu ; for after it had been proved 
that the centre of the Aar glacier moved quicker than the 
side in the ratio of fourteen to one, he accepted the result 
in these words : " The movement of the centre of the gla- 
cier is to that of a point five metres from the edge as 
FOURTEEN to ONE : such is the effect of plasticity ! " f In- 
deed, if the differences exhibited in the table were a proof 
of error, the observations of Professor Forbes himself would 
fare very ill. The measurements of glacier-motion made 
with his own hands vary from less than 42 feet a year to 
848 feet a year, the minimum being less than one-twentieth 
of the maximum ; and if we include the observations made 
by Balmat, the, fidelity of which has been certified by 
Professor Forbes, the minimum is only one-thirty-seventh of 
the maximum. 

There is another point connected with Rendu's theory 
which needs clearing up : " The idea," writes the eminent 
reviewer, "that a glacier is a semifluid body is no doubt 
startling, especially to those who have seen the apparently 
rigid ice of which it is composed. M. Rendu himself 
shrank from the idea, and did not scruple to say that 
' the rigidity of a mass of ice was in direct opposition to 
it;' and we think that Professor Forbes himself must have 
stood aghast when his fancy first associated the notion of 
imperfect fluidity with the solid or even the fissured ice of 
* ' Theorie,' p. 96 f ' Occ. Pap.,' p. 74. 



NORTH BRITISH REVIEW. 307 

the glacier, and when he saw in his mind's eye the glaciers 
of the Alps flowing like a river along their rugged bed. 
A truth like this was above the comprehension and beyond 
the sympathy of the age ; and it required a moral power of 
no common intensity to submit it to the ordeal of a shallow 
philosophy, and the sneers of a presumptuous criticism." 

These are strong words ; but the fact is that, so far 
from " shrinking " from the idea, Eendu affirmed, with a 
clearness and an emphasis which have not been ex- 
ceeded since, that all the phenomena of a river were 
reproduced upon the Mer de Glace ; its deeps, its shal- 
lows, its widenings, its narrowings, its rapids, its places 
of slow motion, and the quicker flow of its centre than 
of its sides. He did not shrink from accepting a differ- 
ence between the central and lateral motion amounting to 
a ratio of ten to one a ratio so large that Professor Forbes 
at one time regarded the acceptance of it as a simple 
absurdity. In this he was perhaps justified ; for his own 
first observations, which, however valuable, were hasty and 
incomplete, gave him a maximum ratio of about one and a 
half to one, while the ratio in some cases was nearly one 
of equality. The observations of Agassiz however show 
that the ratio, instead of being ten to one, may be 
infinity to one ; for the lateral ice may be so held back by 
a local obstacle that in the course of a year it shall make 
no sensible advance at all. 

From one thing only did M. Rendu shrink ; and it is the 
thing regarding which we are still disunited. He shrank 
from stating the physical quality of the ice in virtue of 
which a glacier moved like a river. He demands experi- 
ments upon snow and ice to elucidate this subject. The 
very observations which Professor Forbes regards as proofs 
* are those of which we require the physical explanation. It 
is not the viscous flow, if you please to call it such, of 
the glacier as a whole that here concerns us ; but it 

x 2 



308 THE ICE AND THE GLACIER. 

is the quality of the ice in virtue of which this kind 
of motion is accomplished. Professor Forbes sees this dif- 
ference clearly enough : he speaks of " fissured ice " being 
" flexible " in hand specimens ; he compares the glacier 
to a mixture of ice and sand ; and finally, in a more ma- 
tured paper, falls back for an explanation upon the obser- 
vations of Agassiz regarding the capillaries of the glacier.* 



(15.) 

The measurements of Agassiz and Forbes completely 
verify the anticipations of Rendu ; but no writer with 
whom I am acquainted has added anything essential to 
the Bishop's statements as to the identity of glacier and 
liquid motion. He laid down the conditions of the pro- 
blem with perfect clearness, and, as regards the distribu- 
tion of merit, the point to be decided is the relative 
importance of his idea, and of the measurements which 
were subsequently made. 

The observations on which Professor Forbes based the 
analogy between a glacier and a river are the following : 
In 1842 he fixed four marks upon the Mer de Glace a little 
below the Montanvert, the first of which was 100 yards 
distant from the side of the glacier, while the last was at 

* In all that has been written upon glaciers in this country the above 
passages from the writings of Rendu are unquoted ; and many who mingled 
very warmly in the discussions of the subject were, until quite recently, 
ignorant of their existence. I was long in this condition myself, for I 
never supposed that passages which bear so directly upon a point so much 
discussed, and of such cardinal import, could have been overlooked ; or 
that the task of calling attention to them should devolve upon myself 
nearly twenty years after their publication. Now that they are discovered, 
I conceive no difference of opinion can exist as to the propriety of placing 
them in their true position. 



OBSERVATIONS OF FOEBES. 309 

the centre a or a little beyond it." The relative velocity 
of these four points was found to be 

1-000 1-332 1-356 1-367. 

The first observations were made upon two of these points, 
two others being subsequently added. Professor Forbes 
also determined the velocity of two points on the Glacier 
du Geant, and found the ratio of motion, in the first 
instance, to be as 14 to 32. Subsequent measurements, 
however, showed the ratio to be as 14 to 18, the larger 
motion belonging to the station nearest to the centre of 
the glacier. These are the only measurements which I 
can find in his large work that establish the swifter motion 
of the centre of the glacier ; and in these cases the velocity 
of the centre is compared with that of one side only. In 
no instance that I am aware of, either in 1842 or subse- 
quent years, did Professor Forbes extend his measure- 
ments quite across a glacier ; and as regards completeness 
in this respect, no observations hitherto made can at all 
compare with those executed at the instance of Agassiz 
upon the glacier of the Aar. 

In 1844 Professor Forbes made a series of interesting 
experiments on a portion of the Mer de Glace near 
1' Angle. He divided a length of 90 feet into 45 equal 
spaces, and fixed pins at the end of each. His theodolite 
was placed upon the ice, and in seventeen days he found 
that the ice 90 feet nearer the centre than the theodolite 
had moved 26 inches past the latter. These measurements 
were undertaken for a special object, and completely 
answered the end for which they were intended. 

In 1846 Professor Forbes made another important 
observation. Fixing three stakes at the heights of 8, 54, 
and 143 feet above the bed of the glacier, he found that 
in five days they moved respectively 2-87, 4*18, and 
4*66 feet. The stake nearest the bed moved most slowly, 



310 MEASUREMENTS OF AG-ASSIZ. 

thus showing that the ice is retarded by friction. This 
result was subsequently verified by the measurements of 
M. Martins, and by my own. 

If we add to the above an observation made during 
a short visit to the Aletsch glacier in 1844, which 
showed its lateral retardation, I believe we have before us 
the whole of the measurements executed by Professor 
Forbes, which show the analogy between the motion of a 
glacier and that of a viscous body. 

Illustrative of the same point, we have the elaborate and 
extensive series of measurements executed by M. Wild 
under the direction of M. Agassiz upon the glacier of the 
Aarin 1842, 1843, 1844, and 1845, which exhibit on a 
grand scale, and in the most conclusive manner, the charac- 
ter of the motion of this glacier ; and also show, on close 
examination, an analogy with fluid motion which neither 
M. Agassiz nor Professor Forbes suspected. The former 
philosopher publishes a section in his ' Systeme Glaciaire,' 
entitled ' Migrations of the Centre ; ' in which he shows 
that the middle of the glacier is not always the point of 
swiftest motion. The detection of this fact demonstrates 
the attention devoted by M. Agassiz to the discussion of his 
observations, but he gives no clue to the cause of the 
variation. On inspecting the shape of the valley through 
which the Aar glacier moves, I find that these " migra- 
tions" follow the law established in 1857 upon the Mer de 
Glace, and enunciated at page 286. 

To sum up this part of the question : The idea of semi- 
fluid motion belongs entirely to Eendu ; the proof of the 
quicker central flow belongs in part to Kendu, but almost 
wholly to Agassiz and Forbes ; the proof of the retardation 
of the bed belongs to Forbes alone ; while the discovery 
of the locus of the point of maximum motion belongs, I 
suppose, to me. 



"FACTS AND PRINCIPLES." 811 

FORBES'S THEORY. 

(16.) 

THE formal statement of this theory is given in the follow- 
ing words: t( A glacier is an imperfect fluid, or viscous 
body, which is urged down slopes of a certain inclination 
by the mutual pressure of its parts." The consistency of 
the glacier is illustrated by reference to treacle, honey, 
and tar, and the theory thus enunciated and exemplified is 
called the i Viscous Theory.' 

It has been the subject of much discussion, and great 
differences of opinion are still entertained regarding it. 
Able and sincere men take opposite sides ; and the extra- 
ordinary number of Reviews which have appeared upon the 
subject during the last two years show the interest which 
the intellectual public of England take in the question. 
The chief differences of opinion turn upon the inquiry as 
to what Professor Forbes really meant when he propounded 
the viscous theory ; some affirm one thing, some another, 
and, singularly enough, these differences continue, though 
the author of the theory has at various times published 
expositions of his views. 

The differences referred to arise from the circumstances 
that a sufficient distinction has not been observed between 
facts and principles, and that the viscous theory has assumed 
various forms since its first promulgation. It has been 
stated to me that the theory of Professor Forbes is " the 
congeries of facts" which he has discovered. But it is 
quite evident that no recognition, however ample, of these 
facts would be altogether satisfactory to Professor Forbes 
himself. He claims recognition of his theory,* and no writer 

* " Mr. Hopkins," writes Professor Forbes, "has done me the honour, 
in the memoirs before alluded to, to mention with approbation my observa- 



312 VISCOUS THEOEY; WHAT IS IT? 

with whom I am acquainted makes such frequent use of 
the term. "What then can the viscous theory mean apart 
from the facts ? I interpret it as furnishing the principle 
from which the facts follow as physical consequences that 
the glacier moves as a river because the ice is viscous. In 
this sense only can Professor Forbes's views be called a 
theory ; in any other, his experiments are mere illustrations 
of the facts of glacier motion, which do not carry us a hair's 
breadth towards their physical cause. 

What then is the meaning of viscosity or viscidity ? I 
have heard it defined by men of high culture as " gluey 
tenacity; " and such tenacity they once supposed a glacier to 
possess. If we dip a spoon into treacle, honey, or tar, we can 
draw the substance out into filaments, and the same may be 
done with melted caoutchouc or lava. All these substances 
are viscous, and all of them have been chosen to illustrate 
the physical property in virtue of which a glacier moves. 
Viscosity then consists in the power of being drawn out 
when subjected to a force of tension, the substance, after 
stretching, being in a state of molecular equilibrium, or, in 
other words, devoid of that elasticity which would restore it 
to its original form. This certainly was the idea attached 
to Professor Forbes's words by some of his most strenuous 
supporters, and also by eminent men who have never 
taken part in any controversy on the subject. Mr. Darwin, 
for example, speaks of fel spathic rocks being " stretched " 
while flowing slowly onwards in a pasty condition, in pre- 
cisely the same manner as Professor Forbes believes that 
the ice of moving glaciers is stretched and fissured ; and 
Professor Forbes himself quotes these words of Mr. Darwin 
as illustrative of his theory.* 

tions and experiments on the subject of glaciers. He has been more 
sparing either in praise or criticism of the theory which I have founded 
upon them. Had Mr. Hopkins," &c. Eighth Letter; ' Occ. Papers,'?. 66. 
* ' Occ. Papers,' p. 92. 



THEOKY TESTED. 313 

The question now before us is, Does a glacier exhibit 
that power of yielding to a force of tension which would 
entitle its ice to be regarded as a viscous substance ? 

With a view to the solution of this question Mr. Hirst 
took for me the inclinations of the Mer de Glace and 
all its tributaries in 1857 ; the effect of a change of incli- 
nation being always noted. I will select from those mea- 
surements a few which bear more specially upon the 
subject now under consideration, commencing with the 
Glacier des Bois, down which the ice moves in that state 
of wild dislocation already described. The inclination of 
the glacier above this cascade is 5 10', and that of the 
cascade itself is 22 20', the change of inclination being 
therefore 17 10'. 

In Fig. 221 have protracted the inclination of the cascade 
and of the glacier above it ; the line A B representing the 



Pig. 22. 

former and B C the latter. Now a stream of molten lava, 
of treacle, or tar, would, in virtue of its viscosity, be able 
to flow over the brow at B without breaking across ; but 
this is not the case with the glacier ; it is so smashed and 
riven in crossing this brow, that, to use the words of Pro- 
fessor Forbes himself, a it pours into the valley beneath in 
a cascade of icy fragments." 

But this reasoning will appear much stronger when we 
revert to other slopes upon the Mer de Glace. For ex- 
ample, its inclination above FAngle is 4, and it afterwards 
descends a slope of 9 25', the change of inclination being 
5 25'. If we protract these inclinations to scale, we have 



314 INCLINATIONS OF THE MER BE GLACE. 

the line A B, Fig. 23, representing the steeper slope, and 
B C that of the glacier above it. One would surely think 



Fig. 23. 

that a viscous body could cross the brow B without trans- 
verse fracture, but this the glacier cannot do, and Professor 
Forbes himself pronounces this portion of the Mer de 
Glace impassable. Indeed it was the profound crevasses 
here formed which placed me in a difficulty already 
referred to. Higher up again, the glacier is broken 
on passing from a slope of 3 10' to one of 5. Such 
observations show how differently constituted a glacier is 
from a stream of lava in a " pasty condition," or of treacle, 
honey, tar, or melted caoutchouc, to all which it has been 
compared. In the next section I shall endeavour to 
explain the origin of the crevasses, and shall afterwards 
make a few additional remarks on the alleged viscosity of 
ice. 



CKEVASSES CAUSED BY THE MOTION. 315 

THE CREVASSES. 

(17.) 

HAVING made ourselves acquainted with the motion of 
the glacier, we are prepared to examine those rents, 
fissures, chasms, or, as they are most usually called, 
Crevasses, by which all glaciers are more or less intersected. 
They result from the motion of the glacier, and the 
laws of their formation are deduced immediately from 
those of the motion. The crevasses are sometimes very 
deep and numerous, and apparently without law or order 
in their distribution. They cut the ice into long ridges, 
and break these ridges transversely into prisms ; these 
prisms gradually waste away, assuming, according to 
the accidents of their melting, the most fantastic forms. 
I have seen them like the mutilated statuary of an ancient 
temple, like the crescent moon, like huge birds with out- 
stretched wings, like the claws of lobsters, and like antlered 
deer. Such fantastic sculpture is often to be found on 
the ice cascades, where the riven glacier has piled vast 
blocks on vaster pedestals, and presented them to the 
wasting action of sun and air. In Fig. 24 I have given 
a sketch of a mass of ice of this character, which stood 
in 1859 on the dislocated slope of the Glacier des Bois. 

It is usual for visitors to the Montanvert to descend to 
the glacier, and to be led by their guides to the edges of 
the crevasses, where, being firmly held, they look down into 
them ; but those who have only made their acquaintance 
in this way know but little of their magnitude and beauty 
in the more disturbed portions of glaciers. As might be 
expected, they have been the graves of many a moun- 
taineer ; and the skeletons found upon the glacier prove 
that even the chamois itself, with its elastic muscles and 



316 FANTASTIC ICE-MASSES. 

admirable sureness of foot, is not always safe among the 
crevasses. They are grandest in the higher ice-regions, 







where the snow hangs like a coping over their edges, and 
the water trickling from these into the gloom forms splendid 
icicles. The Gorner Glacier, as we ascend it towards the 
old Weissthor, presents many fine examples of such cre- 
vasses ; the ice being often torn in a most curious and 
irregular manner. You enter a porch, pillared by icicles, 
and look into a cavern in the very body of the glacier, 
encumbered with vast frozen bosses which are fringed all 
round by dependent icicles. At the peril of your life from 
slipping, or from the yielding of the stalactites, you may 
enter these caverns, and find yourself steeped in the blue 
illumination of the place. Their beauty is beyond descrip- 
tion ; but you cannot deliver yourself up, heart and soul, to 
its enjoyment. There is a strangeness about the place which 
repels you, and not without anxiety do you look from your 



BIRTH OF A CREVASSE. 317 

ledge into the darkness below, through which the sound of 
subglacial water sometimes rises like the tolling of dis- 
tant bells. You feel that, however the cold splendours 
of the place might suit a purely spiritual essence, they 
are not congenial to flesh and blood, and you gladly 
escape from its magnificence to the sunshine of the world 
above. 

From their numbers it might be inferred that the 
formation of crevasses is a thing of frequent occurrence 
and easy to observe ; but in reality it is very rarely ob- 
served. Simond was a man of considerable experience upon 
the ice, but the first crevasse he ever saw formed was during 
the setting out of one of our lines, when a narrow rent 
opened beneath his feet, and propagated itself through the 
ice with loud cracking for a distance of 50 or 60 yards. Cre- 
vasses always commence in this way as mere narrow cracks, 
which open very slowly afterwards. I will here describe 
the only case of crevasse-forming which has come under 
my direct observation. 

On the 31st of July, 1857, Mr. Hirst and myself, having 
completed our day's work, were standing together upon 
the Glacier du Geant, when a loud dull sound, like that 
produced by a heavy blow, seemed to issue from the body 
of the ice underneath the spot on which we stood. This 
was succeeded by a series of sharp reports, which were 
heard sometimes above us, sometimes below us, sometimes 
apparently close under our feet, the intervals between the 
louder reports being filled by a low singing noise. We 
turned hither and thither as the direction of the sounds 
varied ; for the glacier was evidently breaking beneath 
our feet, though we could discern no trace of rupture. 
For an hour the sounds continued without our being able 
to discover their source ; this at length revealed itself 
by a rush of air-bubbles from one of the little pools upon 
the surface of the glacier, which was intersected by 



318 MECHANICAL ORIGIN. 

the newly-formed crevasse. We then traced it for some 
distance up and down, but hardly at any place was it 
sufficiently wide to permit the blade of my penknife 
to enter it. M. Agassiz has given an animated descrip- 
tion of the terror of his guides upon a similar occasion, 
and there was an element of awe in our own feelings 
as we heard the evening stillness of the glacier thus 
disturbed. 

With regard to the mechanical origin of the crevasses 
the most vague and untenable notions had been entertained 
until Mr. Hopkins published his extremely valuable 
papers. To him, indeed, we are almost wholly indebted 
for our present knowledge of the subject, my own experi- 
ments upon this portion of the glacier-question being for 
the most part illustrations of the truth of his reasoning. 
To understand the fissures in their more complex aspects 
it is necessary that we should commence with their 
elements. I shall deal with the question in my own 
way, adhering, however, to the mechanical principles upon 
which Mr. Hopkins has based his exposition. 



Let A B, C D, be the bounding sides of a glacier moving 
in the direction of the arrow ; let m, n be two points upon 
the ice, one, m, close to the retarding side of the valley, 
and the other, n, at some distance from it. After a 
certain time, the point m will have moved downwards to 
m', but in consequence of the swifter movement of the 



LINE OF GREATEST STRAIN. 319 

parts at a distance from the sides, n will have moved in 
the same time to n r . Thus the line m n, instead of being 
at right angles to the glacier, takes up the oblique position 
m' n' ; but to reach from m' to n' the line m n would 
have to stretch itself considerably ; every other line that 
we can draw upon the ice parallel to m' n f is in a similar 
state of tension ; or, in other words, the sides of the glacier 
are acted upon by an oblique pull towards the centre. 
Now, Mr. Hopkins has shown that the direction in which 
this oblique pull is strongest encloses an angle of 45 with 
the side of the glacier. 

What is the consequence of this ? Let A B, c D, Fig. 26. 




Fig. 26. 

represent, as before, the sides of the glacier, moving 
in the direction of the arrow ; let the shading lines 
enclose an angle of 45 with the sides. Along these lines 
the marginal ice suffers the greatest strain, and, conse- 
quently across these lines and at right angles to them, the 
ice tends to break and to form marginal crevasses. The 
lines, o p, o p, mark the direction of these crevasses ; they 
are at right angles to the line of greatest strain, and 
hence also enclose an angle of 45 with the side of the 
valley, being obliquely pointed upwards. 

This latter result is noteworthy; it follows from the 
mechanical data that the swifter motion of the centre 
tends to produce marginal crevasses which are inclined 
from the side of the glacier towards its source, and not 



320 MARGINAL AND TRANSVERSE CREVASSES. 

towards its lower extremity. But when we look down 
upon a glacier thus crevassed, the first impression is that 
the sides have been dragged down, and have left the 
central portions behind them ; indeed, it was this very 
appearance that led M. de Charpentier and M. Agassiz 
into the error of supposing that the sides of a glacier 
moved more quickly than its middle portions ; and it was 
also the delusive aspect of the crevasses which led Pro- 
fessor Forbes to infer the slower motion of the eastern 
side of the Mer de Glace. 

The retardation of the ice is most evident near the 
sides ; in most cases, the ice for a considerable distance 
right and left of the central line moves with a sensibly 
uniform velocity; there is no dragging of the particles 
asunder by a difference of motion, and, consequently, a 
compact centre is perfectly compatible with fissured 
sides. Nothing is more common than to see a glacier 
with its sides deeply cut, and its central portions com- 
pact; this, indeed, is always the case where the glacier 
moves down a bed of uniform inclination. 

But supposing that the bed is not uniform that the 
valley through which the glacier moves changes its incli- 
nation abruptly, so as to compel the ice to pass over a 
brow ; the glacier is then circumstanced like a stick 
which we try to break by holding its two ends and pressing 
it against the knee. The brow, where the bed changes 
its inclination, represents the knee in the case of the 
stick, while the weight of the glacier itself is the force 
that tends to break it. It breaks ; and fissures are 
formed across the glacier, which are hence called transverse 
crevasses. 

No glacier with which I am acquainted illustrates the 
mechanical laws just developed more clearly and fully 
than the Lower glacier of Grindelwald. Proceeding along 
the ordinary track beside the glacier, at about an hour's 



GRIKDELWALD GLACIER, 321 

distance from the village the traveller reaches a point 
whence a view of the glacier is obtained from the 
heights above it. The marginal fissures are very cleanly 
cut, and point nearly in the direction already indicated ; 
the glacier also changes its inclination several times 
along the distance within the observer's view. On crossing 
each brow the glacier is broken across, and a series of 
transverse crevasses is formed, which follow each other 
down the slope. At the bottom of the slope tension 
gives place to pressure, the walls of the crevasses are 
squeezed together, and the chasms closed up. They 
remain closed along the comparatively level space which 
stretches between the base of one slope and the brow of 
the next; but here the glacier is again transversely broken, 
and continues so until the base of the second slope is 
reached, where longitudinal pressure instead of longitu- 
dinal strain begins to act, and the fissures are closed 
as before. In Fig. 27A I have given a sketchy section of 
a portion of the glacier, illustrating the formation of the 
crevasses at the top of a slope, and their subsequent 
obliteration at its base. 

Another effect is here beautifully shown, namely, the 
union of the transverse and marginal crevasses to form con- 
tinuous fissures which stretch quite across the glacier. Fig. 
2?B will illustrate my meaning, though very imperfectly; 
it represents a plan of a portion of the Lower Grindelwald 
glacier, with both marginal and transverse fissures drawn 
upon it. I have placed it under the section so that each 
part of it may show in plan the portion of the glacier which 
is shown in section immediately above it. It shows 
how the marginal crevasses remain after the compres- 
sion of the centre has obliterated the transverse ones ; 
and how the latter join on to the former, so as to 
form continuous fissures, which sweep across the glacier 
in vast curves, with their convexities turned upwards. 

y 



322 



COMPKESSION AND TENSION. 



The illusion before referred to is here strengthened ; the 
crevasses turn, so to say, against the direction of motion, 




instead of forming loops, with their convexities pointing 
downwards, and thus would impress a person unacquainted 
with the mechanical data with the idea that the glacier 
margins moved more quickly than the centre. The figures 
are intended to convey the idea merely ; on the actual 
slopes of the glacier between twenty and thirty chasms 
may be counted : also the word " compression " ought to 
have been limited to the level portions of the sketch. 

Besides the two classes of fissures mentioned we often 
find others, which are neither marginal nor transverse. 
The terminal portions of many glaciers, for example, are 
in a state of compression ; the snout of the glacier abuts 
against the ground, and having to bear the thrust of the 
mass behind it, if it have room to expand laterally, the ice 



LONGITUDINAL CKEVASSES. 323 

will yield, and longitudinal crevasses will be formed. They 
are of very common occurrence, but the finest example 
of the kind is perhaps exhibited by the glacier of the 
Rhone. After escaping from the steep gorge which holds 
the cascade, this glacier encounters the bottom of a com- 
paratively wide and level valley ; the resistance to its for- 
ward motion is augmented, while its ability to expand 
laterally is increased ; it has to bear a longitudinal thrust, 
and it splits at right angles to the pressure [strain ?]. A 
series of fissures is thus formed, the central ones of which 
are truly longitudinal ; but on each side of the central line 
the crevasses diverge, and exhibit a fan-like arrangement. 
This disposition of the fissures is beautifully seen from the 
summit of the Mayenwand 011 the Grimsel Pass. 

Here then we have the elements, so to speak, of glacier- 
crevassing, and through their separate or combined action 
the most fantastic cutting up of a glacier may be effected. 
And see how beautifully these simple principles enable 
us to account for the remarkable crevassing of the 
eastern side of the Mer 
de Glace. Let A B, c D, c, 
be the opposite sides of a 
portion of the glacier, near 
theMontanvert; c D being 
east, and A B west, the 

glacier moving in the di- A Montanvert 

rection of the arrow ; let Fi - 28 - 

the points m n represent the extremities of our line of 
stakes, and let us suppose an elastic string stretched across 
the glacier from one to the other. We have proved that 
the point of maximum motion here lies much nearer to 
the side c D than to A B. Let o be this point, and, seizing 
the string at o, let it be drawn in the direction of motion 
until it assumes the position, m, o', n. It is quite evident 
that o' n is in a state of greater tension than o' m, and the 




324 CKEVASSING- OF CONVEX SIDE. 

ice at the eastern side of the Mer de Glace is in a precisely 
similar mechanical condition. It suffers a greater strain 
than the ice at the opposite side of the valley, and hence is 
more fissured and broken. Thus we see that the crevassing 
of the eastern side of the glacier is a simple consequence 
of the quicker motion of that side, and does not, as hitherto 
supposed, demonstrate its slower motion. The reason why 
the eastern side of the glacier, as a whole, is much more 
fissured than the western side is, that there are two long 
segments which turn their convex curvature eastward, and 
only one segment of the glacier which turns its convexity 
westward. 

The lower portion of the Rhone glacier sweeps round 
the side of the valley next the Furca, and turns through- 
out a convex curve to this side : the crevasses here are 
wide and frequent, while they are almost totally absent at 
the opposite side of the glacier. The lower Grindelwald 
glacier turns at one place a convex curve towards the 
Eiger, and is much more fissured at that side than at 
the opposite one ; indeed, the fantastic ice - splinters, 
columns, and minarets, which are so finely exhibited upon 
this glacier, are mainly due to the deep crevassing of the 
convex side. Numerous other illustrations of the law might, 
I doubt not, be discovered, and it would be a pleasant and 
useful occupation to one who takes an interest in the sub- 
ject, to determine, by strict measurements upon other gla- 
ciers, the locus of the point of maximum motion, and 
to observe the associated mechanical effects. 

The appearance of crevasses is often determined by cir- 
cumstances more local and limited than those above indi- 
cated ; a boss of rock, a protuberance on the side of the 
flanking mountain, anything, in short, which checks the 
motion of one part of the ice and permits an adjacent 
portion to be pushed away from it, produces crevasses. 
Some valleys are terminated by a kind of mountain-circus 



BEEGSCHRUNDS. 325 

with steep sides, against which the snow rises to a con- 
siderable height. As the mass is urged downwards, the 
lower portion of the snow-slope is often torn away from its 
higher portion, and a chasm is formed, which usually 
extends round the head of the valley. To such a crevasse 
the specific name Bergschrund is applied in the Bernese 
Alps ; I have referred to one of them in the account of 
the " Passage of the Strahleck." 



(18.) 

The phenomena described and accounted for in the last 
chapter have a direct bearing upon the question of visco- 
sity. In virtue of the quicker central flow the lateral ice 
is subject to an oblique strain ; but, instead of stretching, 
it breaks, and marginal crevasses are formed. We also see 
that a slight curvature in the valley, by throwing an addi- 
tional strain upon one half of the glacier, produces an 
augmented crevassing of that side. 

But it is known that a substance confessedly viscous may 
be broken by a sudden shock or strain. Professor Forbes 
justly observes that sealing-wax at moderate temperatures 
will mould itself (with time) to the most delicate inequa- 
lities of the surface on which it rests, but may at the same 
time be shivered to atoms by the blow of a hammer. 
Hence, in order to estimate the weight of the objection 
that a glacier breaks when subjected to strain, we must 
know the conditions under which the force is applied. 

The Mer de Glace has been shown (p. 287) to move 
through the neck of the valley at Trelaporte at the rate of 
twenty inches a day. Let the sides of this page represent 
the boundaries of the glacier at Trelaporte, and any one of 
its lines of print a transverse slice of ice. Supposing the line 



326 NUMEEICAL TEST OF VISCOSITY. 

to move down the page as the slice of ice moves down the 
valley, then the bending of the ice in twenty-four hours, 
shown on such a scale, would only be sufficient to push 
forward the centre in advance of the sides by a very small 
fraction of the width of the line of print. To such an 
extremely gradual strain the ice is unable to accommodate 
itself without fracture. 

Or, referring to actual numbers : the stake No. 15 on 
our 5th line, page 284, stood on the lateral moraine of the 
Mer de Glace ; and between it and No. 14 a distance of 
190 feet intervened. Let A B, Fig. 29, be the side of the 
glacier, moving in the direction of the arrow, 
and let a ~b c d be a square upon the glacier 
with a side of 190 feet. The whole square 
moves with the ice, but the side b d moves 
quickest ; the point a moving 10 inches, 
while b moves 14-75 inches in 24 hours ; the 
differential motion therefore amounts to an 
inch in five hours. Let a b r d' c be the 
shape of the figure after five hours' motion ; 
then the line a b would be extended to a b r 
Fig. 29. and c d to cd r . 
The extension of these lines does not however express the 
maximum strain to which the ice is subjected. Mr. Hop- 
kins has shown that this takes place along the line ad; in 
five hours then this line, if capable of stretching, would be 
stretched to ad'. From the data given every boy who has 
mastered the 47th Proposition of the First Book of Euclid 
can find the length both of a d and a d' ; the former is 
3224-4 inches, and the latter is 3225-1, the difference be- 
tween them being seven-tenths of an inch. 

This is the amount of yielding required from the ice 
in five hours, but it cannot grant this ; the glacier breaks, 
and numerous marginal crevasses are formed. It must 
not be forgotten that the evidence here adduced merely 




STRETCHING OF ICE NOT PROVED. 327 

shows what ice cannot do ; what it can do in the way of 
viscous yielding we do not know : there exists as yet no 
single experiment on great masses or small to show that 
ice possesses in any sensible degree that power of being 
drawn out which seems to be the very essence of viscosity. 

I have already stated that the crevasses, on their first 
formation, are exceedingly narrow rents, which widen very 
slowly. The new crevasse observed by our guide required 
several days to attain a width of three inches ; while that 
observed by Mr. Hirst and myself did not widen a single 
inch in three days. This, I believe, is the general cha- 
racter of the crevasses ; they form suddenly and open 
slowly. Both facts are at variance with the idea that ice 
is viscous ; for were this substance capable of stretching at 
the slow rate at which the fissures widen, there would be 
no necessity for their formation. 

It cannot be too clearly and emphatically stated that 
the proved fact of a glacier conforming to the law of semi- 
fluid motion is a thing totally different from the alleged 
fact of its being viscous. Nobody since its first enuncia- 
tion disputed the former. I had no doubt of it when I 
repaired to the glaciers in 1856 ; and none of the eminent 
men who have discussed this question with Professor 
Forbes have thrown any doubt upon his measurements. 
It is the assertion that small pieces of ice are proved to 
be viscous * by the experiments made upon glaciers, and 
fhe consequent impression left upon the public mind 
that ice possesses the " gluey tenacity " which the term 
viscous suggests to which these observations are meant 
to apply. 

* " The viscosity, though it cannot be traced in the parts if very minute 
nevertheless exists there, as unequivocally proved by experiments on the 
large scale." Forbes in ' Phil. Mag.,' vol. x., p. 301. 



328 CONNEXION OF NATURAL FORCES. 



HEAT AND WORK. 

(19.) /'.; . 

GREAT scientific principles, though usually announced by 
individuals, are often merely the distinct expression of 
thoughts and convictions which had long been entertained 
by all advanced investigators. Thus the more profound 
philosophic thinkers had long suspected a certain equiva- 
lence and connexion between the various forces of nature ; 
experiment had shown the direct connexion and mutual 
convertibility of many of them, and the spiritual insight, 
which, in the case of the true experimenter, always sur- 
rounds and often precedes the work of his hands, revealed 
more or less plainly that natural forces either had a 
common root, or that they formed a circle, whose links 
were so connected that by starting from any one of them 
we could go through the circuit, and arrive at the point 
from which we set out. For the last eighteen years 
this subject has occupied the attention of some of the 
ablest natural philosophers, both in this country and on 
the Continent. The connexion, however, which has most 
occupied their minds is that between heat and work ; the 
absolute numerical equivalence of the two having, I 
believe, been first announced by a German physician 
named Mayer, and experimentally proved in this country 
by Mr. Joule. 

A lead bullet may be made hot enough to burn the 
hand, by striking it with a hammer, or by rubbing it against 
a board ; a clever blacksmith can make a nail red-hot by 
hammering it ; Count Rumford boiled water by the heat 
developed in the boring of cannon, and inferred from the 
experiment that heat was not what it was generally 



MECHANICAL EQUIVALENT OF HEAT. 329 

supposed to be, an imponderable fluid, but a kind of 
motion generated by the friction. Now Mr. Joule's 
experiments enable us to state the exact amount of heat 
which a definite expenditure of mechanical force can ori- 
ginate. I say originate, not drag from any hiding-place in 
which it had concealed itself, but actually bring into exist- 
ence, so that the total amount of heat in the universe is 
thereby augmented. If a mass of iron fall from a tower 
770 feet in height, we can state the precise amount of heat 
developed by its collision with the earth. Supposing all 
the heat thus generated to be concentrated in the iron 
itself, its temperature would thereby be raised nearly 10 
Fahr. Gravity in this case has expended a certain amount 
of force in pulling the iron to the earth, and this force is 
the mechanical equivalent of the heat generated. Further- 
more, if we had a machine so perfect as to enable us to 
apply all the heat thus produced to the raising of a weight, 
we should be able, by it, to lift the mass of iron to the 
precise point from which it fell. 

But the heat cannot lift the weight and still continue 
heat; this is the peculiarity of the modern view of the 
matter. The heat is consumed, used up, it is no longer 
heat ; but instead of it we have a certain amount of gravi- 
tating force stored up, which is ready to act again, and to 
regenerate the heat when the weight is let loose. In fact, 
when the falling weight is stopped by the earth, the motion 
of its mass is converted into a motion of its molepules ; 
when the weight is lifted by heat, molecular motion is con- 
verted into ordinary mechanical motion, but for every 
portion of either of them brought into existence an equiva- 
lent portion of the other must be consumed. 

What is true for masses is also true for atoms. As the 

' earth and the piece of iron mutually attract each other, 

and produce heat by their collision, so the carbon of a 

burning candle and the oxygen of the surrounding air 



330 HEAT PEODUCED IF THE EAETH STRUCK THE SUN. 

mutually attract each other ; they rush together, and on 
collision the arrested motion becomes heat. In the former 
case we have the conversion of gravity into heat, in the 
latter the conversion of chemical affinity into heat ; 
but in each case the process consists in the generation 
of motion by attraction, and the subsequent change of 
that motion into motion of another kind. Mechanically 
considered, the attraction of the atoms and its results is 
precisely the same as the attraction of the earth and 
weight and its results. 

But what is true for an atom is also true for a planet or a 
sun. Supposing our earth to be brought to rest in her orbit 
by a sudden shock, we are able to state the exact amount of 
heat which would be thereby generated. The consequence 
of the earth's being thus brought to rest would be that it 
would fall into the sun, and the amount of heat which 
would be generated by this second collision is also calcul- 
able. Helmholtz has calculated that in the former case 
the heat generated would be equal to that produced by 
the combustion of fourteen earths of solid coal, and in 
the latter case the amount would be 400 times greater. 

Whenever a weight is lifted by a steam-engine in oppo- 
sition to the force of gravity an amount of heat is consumed 
equivalent to the work done ; and whenever the molecules 
of a body are shifted in opposition to their mutual attractions 
work is also performed, and an equivalent amount of heat 
is consumed. Indeed the amount of work done in the 
shifting of the molecules of a body by heat, when expressed 
in ordinary mechanical work, is perfectly enormous. The 
lifting of a heavy weight to the height of 1000 feet maybe 
as nothing compared with the shifting of the atoms of a body 
by an amount so small that our finest means of measure- 
ment hardly enable us to determine it. Different bodies 
give heat different degrees of trouble, if I may use the term, 
in shifting their atoms and putting them in new places. 



SHIFTING OF ATOMS. 331 

Iron gives more trouble than lead ; and water gives far more 
trouble than either. The heat expended in this molecular 
work is lost as heat ; it does not show itself as temperature. 
Suppose the heat produced by the combustion of an ounce 
of candle to be concentrated in a pound of iron, a certain 
portion of that heat would go to perform the molecular 
work to which I have referred, and the remainder would be 
expended in raising the temperature of the body ; and if 
the same amount of heat were communicated to a pound 
of iron and to a pound of lead, the balance in favour of 
temperature would be greater in the latter case than in the 
former, because the heat would have less molecular work 
to do ; the lead would become more heated than the iron. 
To raise a pound of iron a certain number of degrees in 
temperature would, in fact, require more than three times 
the absolute quantity of heat which would be required to 
raise a pound of lead the same number of degrees. Con- 
versely, if we place the pound of iron and the pound of lead, 
heated to the same temperature, into ice, we shall find that 
the quantity of ice melted by the iron will be more than 
three times that melted by the lead. In fact, the greater 
amount of molecular work invested in the iron now comes 
into play, the atoms again obey their own powerful forces, 
and an amount of heat corresponding to the energy of 
these forces is generated. 

This molecular work is that which has usually been called 
specific heat, or capacity for heat. According to the mate- 
rialistic view of heat, bodies are figured as sponges, and heat 
as a kind of fluid absorbed by them, different bodies pos- 
sessing different powers of absorption. According to the 
dynamic view, as already explained, heat is regarded as a 
motion, and capacity for heat indicates the quantity of that 
motion consumed in internal changes. 

The greatest of these changes occurs when a body passes 
from one state of aggregation to another, from the solid 



332 HEAT CONSUMED IN MOLECULAR WORK. 

to the liquid, or from the liquid to the aeriform state ; and 
the quantity of heat required for such changes is often 
enormous. To convert a pound of ice at 32 Fahr. into 
water at the same temperature would require an amount 
of heat competent, if applied as mechanical force, to 
lift the same pound of ice to a height of 110,000 feet; 
it would raise a ton of ice nearly 50 feet, or it would 
lift between 49 and 50 tons to a height of one foot 
above the earth's surface. To convert a pound of water at 
212 into a pound of steam at the same temperature would 
require an amount of heat which would perform nearly 
seven times the amount of mechanical work just mentioned. 

This heat is entirely expended in interior work* and does 
nothing towards augmenting the temperature ; the water 
is at the temperature of the ice which produced it, both 
are 32 ; and the steam is at the temperature of the water 
which produced it, both are 212. The whole of the heat 
is consumed in producing the change of aggregation ; I 
say " consumed" not hidden or "latent" in either the water 
or the steam, but absolutely non-existent as heat. The 
molecular forces, however, which the heat has sacrificed 
itself to overcome are able to reproduce it ; the water in 
freezing and the steam in condensing give out the exact 
amount of heat which they consumed when the change of 
aggregation was in the opposite direction. 

At a temperature of several degrees below its freezing 
point ice is much harder than at 32. I have more than 
once cooled a sphere of the substance in a bath of solid 
carbonic acid and ether to a temperature of 100 below the 
freezing point. During the time of cooling the ice crackled 
audibly from its contraction, and afterwards it quite resisted 
the edge of a knife ; while at 32 it may be cut or crushed 
with extreme facility. The cold sphere was subjected to 

* I borrow this term from Professor Clausius's excellent papers on the 
Dynamical Theory of Heat. 






ICE NEAR THE MELTING POINT. 333 

pressure ; it broke with the detonation of a vitreous body, 
and was taken from the press a white opaque powder ; which, 
on being subsequently raised to 32 and again compressed, 
was converted into a pellucid slab of ice. 

But before the temperature of 32 is quite attained, ice 
gives evidence of a loosening of its crystalline texture. 
Indeed the unsoundness of ice at and near its melting 
point has been long known. Sir John Leslie, for example, 
states that ice at 32 is friable ; and every skater knows how 
rotten ice becomes before it thaws. M. Person has further 
shown that the latent heat of ice, that is to say, the quantity 
of heat necessary for its liquefaction, is not quite expressed 
by the quantity consumed in reducing ice at 32 to the liquid 
state. The heat begins to be rendered latent, or in other 
words the change of aggregation commences, a little before 
the substance reaches 32, a conclusion which is illus- 
trated and confirmed by the deportment of melting ice 
under pressure. 

In reference to the above result Professor Forbes 
writes as follows : " I have now to refer to a fact .... 
established by a French experimenter, M. Person, who 
appears not to have had even remotely in his mind the 
theory of glaciers, when he announced the following facts, 
viz. * That ice does not pass abruptly from the solid to the 
fluid state ; that it begins to soften at a temperature of 
2 Centigrade below its thawing point ; that, consequently, 
between 28 4' and 32 of Fahr. ice is actually passing 
through various degrees of plasticity within narrower limits, 
but in the same manner that wax, for example, softens be- 
fore it melts.' " The " softening " here referred to is the 
"friability," of Sir J. Leslie, and what I have called a 
" loosening of the texture." Let us suppose the Serpentine 
covered by a sheet of pitch so smooth and hard as to 
enable a skater to glide over it ; and which is afterwards 
gradually warmed until it begins to bend under his weight, 



334 ROTTEN ICE AND SOFTENED WAX. 

and finally lets him through. A comparison of this 
deportment with that of a sheet of ice under the same 
circumstances enables us to decide whether ice "passes 
through various degrees of plasticity in the same manner 
as wax softens before it melts." M. Person concerned 
himself solely with the heat absorbed, and no doubt 
in both wax and ice that heat is expended in " interior 
work." In the one case, however, the body is so consti- 
tuted that the absorbed heat' is expended in rendering the 
substance viscous ; and the question simply is, whether the 
heat absorbed by the ice gives its molecules a freedom of 
play which would entitle it also to be called viscous ; 
whether, in short, "rotten ice" and softened wax present 
the same physical qualities ? 



(20.) 

There is one other point in connexion with the viscous 
theory which claims our attention. The announcement of 
that theory startled scientific men, and for two or three 
years after its first publication it formed the subject of 
keen discussion. This finally subsided, and afterwards 
Professor Forbes drew up an elaborate paper, which was 
presented in three parts to the Royal Society in 1845 
and 1846, and subsequently published in the c Philosophical 
Transactions.' 

In the concluding portion of Part III. Professor Forbes 
states and answers the question, " How far a glacier is to 
be regarded as a plastic mass ? " in these words : " Were 
a glacier composed of a solid crystalline cake of ice, fitted 
or moulded to the mountain bed which it occupies, 
like a lake tranquilly frozen, it would seem impossible 
to admit such a flexibility or yielding of parts as should 



CAPILLARY HYPOTHESIS. 335 

permit any comparison to a fluid or semifluid body, trans- 
mitting pressure horizontally, and whose parts might 
change their mutual positions so that one part should be 
pushed out whilst another remained behind. But we 
know, in point of fact, that a glacier is a body very dif- 
ferently constituted. It is clearly proved by the experi- 
ments of Agassiz and others that the glacier is not a mass 
of ice, but of ice and water, the latter percolating freely 
through the crevices of the former to all depths of the gla- 
cier ; and it is a matter of ocular demonstration that these 
crevices, though very minute, communicate freely with 
one another to great distances ; the water with which they 
are filled communicates force also to great distances, and 
exercises a tremendous hydrostatic pressure to move on- 
wards in the direction in which gravity urges it, the vast 
porous mass of seemingly rigid ice in which it is as it 
were bound up." 

" Now the water in the crevices," continues Professor 
Forbes, " does not constitute the glacier, but only the 
principal vehicle of the force which acts on it, and the slow 
irresistible energy with which the icy mass moves onwards 
from hour to hour with a continuous march, bespeaks of 
itself the presence of a fluid pressure. But if the ice were 
not in some degree ductile or plastic, this pressure could 
never produce any the least forward motion of the mass. 
The pressure in the capillaries of the glacier can only tend 
to separate one particle from another, and thus produce 
tensions and compressions within the body of the glacier 
itself j which yields, owing to its slightly ductile nature, in 
the direction of least resistance, retaining its continuity, 
or recovering it by reattachment after its parts have suffered 
a bruise, according to the violence of the action to which it 
has been exposed." 

I will not pretend to say that I fully understand this 
passage, but, taking it and the former one together, I think 



336 TEMPEEATUEE AT CHAMOUNI ; WINTEE 1859. 

it is clear that the water which is. supposed to gorge 
the capillaries of the glacier is assumed to be essential 
to its motion. Indeed, an extreme degree of sensitiveness 
has been ascribed to the glacier as regards the changes of 
temperature by which the capillaries are affected. In 
three succeeding days, for example, Professor Forbes 
found the diurnal summer motion of a point upon the 
Mer de Glace to increase from 15*2 to 17 '5 inches a 
day; a result which he says he is "persuaded" to be 
due to the increasing heat of the weather at the time. 
If, then, the glacier capillaries can be gorged so quickly 
as this experiment would indicate, it is fair to assume that 
they are emptied with corresponding speed when the 
supply is cut away. 

The extraordinary coldness of the weather previous to 
the Christmas of 1859 is in the recollection of everybody : 
this lowness of temperature also extended to the Mer de 
Glace and its environs. I had last summer left with 
Auguste Balmat and the Abbe Vueillet thermometers 
with which observations were made daily during the cold 
weather referred to. I take the following from Balmat's 
register. 



Date. 

December 16 
17 
18 
19 
20 
21 
22 


Minimum 
temperature 
Centigrade. 
- 15 


Da 
Decei 




te. 

nber 23 ... 
24 ... 

25 ... 

27 ... 

28 


Minimur 
temperati 
Centigrac 

... ~ 4; 
... 61 
... - 2' 

... + 2 
... - 3 
- 10 


- 20 

-16* 

- 9 
- 13 


- 4f 


29 


- 6 



The temperature at the Montanvert during the above 
period may be assumed as generally some degrees lower, so 
that for a considerable period, previous to my winter observa- 
tions, the portion of the Mer de Glace near the Montanvert 
had been exposed to a very low temperature. I reached 



BALMAT'S MEASUREMENTS. 337 

the place after the weather had become warm, but during 
my stay there the maximum temperature did not exceed 
41 0. Considering therefore the long drain to which the 
glacier had been subjected previous to the 29th of Decem- 
ber, it is not unreasonable to infer that the capillary supply 
assumed by Professor Forbes must by that time have been 
exhausted. Notwithstanding this, the motion of the glacier 
at the Montanvert amounted at the end of December to 
half its maximum summer motion. 

The observations of Balmat which have been published 
by Professor Forbes * also militate, as far as they go, 
against the idea of proportionality between the capillary 
supply and the motion. If the temperatures recorded 
apply to the Mer de Glace during the periods of observa- 
tion, it would follow that from the 19th of December 1846 
to the 12th of April 1847 the temperature of the air was 
constantly under zero Centigrade, and hence, during this 
time, the gorging of the capillaries, which is due to super- 
ficial melting, must have ceased. Still, throughout this 
entire period of depletion the motion of the glacier steadily 
increased from twenty-four inches to thirty-four and a half 
inches a day. What has been here said of the Montan- 
vert, and of the points lower down where Balmat's measure- 
ments were made, of course applies with greater force to 
the higher portions of the glacier, which are withdrawn 
from the operation of superficial melting for a longer 
period, and which, nevertheless, if I understand Professor 
Forbes aright, have their motion least affected in winter. 
He records, for example, an observation of Mr. Bakewell's, 
by which the Glacier des Bossons is shown to be stationary 
at its end, while its upper portions are moving at the rate 
of a foot a day. This surely indicates that, at those places 
* where the glacier is longest cut off from superficial supply, 
the motion is least reduced, which would be a most strange 

* ' Occ. Pap.,' p. 224. 



338 BAKEWELL'S OBSERVATIONS. 

result if the motion depended, as affirmed, upon the gorging 
of the capillaries. 

The perusal of the conclusion of Professor Forbes's last 
volume shows me that a thought similar to that expressed 
above occurred to Mr. Bakewell also. Speaking of a 
shallow glacier which moved when the alleged tempera- 
ture was so enormously below the freezing point that Pro- 
fessor Forbes regards the observation as open to question 
(in which I agree with him), Mr. Bakewell asks, " Is it 
possible that infiltrated water can have any action what- 
ever under such circumstances?" The reply of Professor 
Forbes contains these words : " I have nowhere affirmed 
the presence of liquid water to be a sine qua non to the 
plastic motion of glaciers." This statement, I confess, 
took me by surprise, which was not diminished by further 
reading. Speaking of the influence of temperature on the 
motion of the Mer de Glace, Professor Forbes says, the 
glacier u took no real start until the frost had given way, 
and the tumultuous course of the Arveiron showed that 
its veins were again filled with the circulating medium to 
which the glacier, like the organic frame, owes its moving 
energy." * And again : " It is this fragility precisely 
which, yielding to the hydrostatic pressure of the unfrozen 
water contained in the countless capillaries of the glacier, 
produces the crushing action which shoves the ice over its 
neighbour particles." f 

After the perusal of the foregoing paragraphs the reader 
will probably be less interested in the question as to 
whether the assumed capillaries exist at all in the glacier. 
According to Mr. Huxley's observations, they do not 4 
During the summer of 1857 he carefully experimented 
with coloured liquids on the Mer de Glace and its tribu- 
taries, and in no case was he able to discover these fissures 

* ' Phil. Trans.,' 1846, p. 137, and ' Occ. Pap.,' p. 138. 

t ' Occ. Pap.,' p. 47. 1 ' Phil. Mag.,' 1857, vol. xiv., p. 241. 



HUXLEY'S OBSEEVATIONS. 339 

in the sound unweathered ice. I have myself seen the red 
liquid resting in an auger-hole, where it had lain for an 
hour without diffusing itself in any sensible degree. This 
cavity intersected both the white ice and the blue veins 
of the glacier ; and Mr. Huxley, in my presence, cut away 
the ice until the walls of the cavity became extremely thin, 
still no trace of liquid passed through them. Experiments 
were also made upon the higher portions of the Mer de 
Glace, and also on the Glacier du Geant, with the same 
result. Thus the very existence of these capillaries is 
rendered so questionable, that no theory of glacier-motion 
which invokes their aid could be considered satisfactory. 



z 2 



340 STATEMENT OF THEOEY. 

THOMPSON'S THEORY. 

(21.) 

IN the * Transactions ' of the Royal Society of Edinburgh for 
1849 is published a very interesting paper by Prof. James 
Thomson of Queen's College, Belfast, wherein he deduces, 
as a consequence of a principle announced by the French 
philosopher Carnot, that water, when subjected to pressure, 
requires a greater cold to freeze it than when the pressure is 
removed. He inferred that the lowering of the freezing 
point for every atmosphere of pressure amounted to '0075 
of a degree Centigrade. This deduction was afterwards 
submitted to the test of experiment by his distinguished 
brother Prof. Wm. Thomson, and proved correct. On the 
fact thus established is founded Mr. James Thomson's theory 
of the " Plasticity of Ice as manifested in Glaciers." 

The theory is this : Certain portions of the glacier are 
supposed first to be subjected to pressure. This pressure 
liquefies the ice, the water thus produced being squeezed 
through the glacier in the direction in which it can most 
easily escape. But cold has been evolved by the act of 
liquefaction, and, when the water has been relieved from 
the pressure, it freezes in a new position. The pressure 
being thus abolished at the place where it was first applied, 
new portions of the ice are subjected to the force ; these 
in their turn liquefy, the water is dispersed as before, 
and re-frozen in some other place. To the succession .of 
processes here assumed Mr. Thomson ascribes the changes 
of form observed in glaciers. 

This theory was first communicated to the Royal Society 
through the author's brother, Prof. William Thomson, and 
is printed in the ' Proceedings ' of the Society for May, 1857. 
It was afterwards communicated to the British Association 



DIFFICULTIES OF THEORY. 341 

in Dublin, in whose ( Reports ' it is further published ; and 
again it was communicated to the Belfast Literary and 
Philosophical Society, in whose ' Proceedings ' it also finds 
a place. 

On the 24th of November, 1859, Mr. James Thomson 
communicated to the Royal Society, through his brother, 
a second paper, in which he again draws attention to his 
theory. He offers it in substitution for my views as the 
best argument that he can adduce against them ; he also 
controverts the explanations of regelation propounded by 
Prof. James D. Forbes and Prof. Faraday, believing that 
his own theory explains all the facts so well as to leave 
room for no other. 

But the passage in this paper which demands my chief 
attention is the following : " Prof. Tyndall (writes Mr. 
Thomson), in papers and lectures subsequent to the publi- 
cation of this theory, appears to adopt it to some extent, 
and to endeavour to make its principles co-operate with 
the views he had previously founded on Mr. Faraday's fact 
of regelation." I may say that Mr. Thomson's main 
thought was familiar to me long before his first communi- 
cation on the plasticity of ice appeared ; but it had little 
influence upon my convictions. Were the above passage 
correct, I should deserve censure for neglecting to express 
my obligations far more explicitly than I have hitherto 
done ; but I confess that even now I do not understand 
the essential point of Mr. Thomson's theory, that is to 
say, its application to the phenomena of glacier motion. 
Indeed, it was the obscurity in my mind in connexion with 
this point, and the hope that time might enable me to 
seize more clearly upon his meaning, which prevented me 
from giving that prominence to the theory of Mr. Thomson 
which, for aught I know, it may well deserve. I will 
here briefly state one or two of my difficulties, and shall 
feel very grateful to have them removed. 



342 IMPKOBABLE DEDUCTION. 

Let us fix our attention on a vertical slice of ice trans- 
verse to the glacier, and to which the pressure is applied 
perpendicular to its surfaces. The ice liquefies, and, sup- 
posing the means of escape offered to the compressed water 
to be equal all round, it is plain that there will be as great 
a tendency to squeeze the water upwards as downwards; 
for the mere tendency to flow down by its own gravity 
becomes, in comparison to the forces here acting on the 
water, a vanishing quantity. But the fact is, that the ice 
above the slice is more permeable than that below it ; for, 
as we descend a glacier, the ice becomes more compact. 
Hence the greater part of the dispersed water will be re- 
frozen on that side of the slice which is turned towards 
the origin of the glacier; and the consequence is, that, 
according to Mr. Thomson's principle, the glacier ought 
to move up hill instead of down. 

I would invite Mr. Thomson to imagine himself and me 
together upon the ice, desirous of examining this question 
in a philosophic spirit ; and that we have taken our places 
beside a stake driven into the ice, and descending with the 
glacier. We watch the ice surrounding the stake, and find 
that every speck of dirt upon it retains its position ; there 
is no liquefaction of the ice that bears the dirt, and con- 
sequently it rests on the glacier undisturbed. After twelve 
hours we find the stake fifteen inches distant from its first 
position : I would ask Mr. Thomson how did it get there ? 
Or let us fix our attention on those six stakes which M. 
Agassiz drove into the glacier of the Aar in 1841, and 
found erect in 1842 at some hundreds of feet from their 
first position : how did they get there ? How, in fine, 
does the end of a glacier become its end ? Has it been 
liquefied and re-frozen ? If not, it must have been pushed 
down by the very forces which Mr. Thomson invokes to 
produce his liquefaction. Both the liquefaction, as far as 
it exists, and the motion, are products of the same cause. 



REQUISITE PRESSURE CALCULATED. 343 

In short, this theory, as it presents itself to my mind, 
is so powerless to account for the simplest fact of glacier- 
motion, that I feel disposed to continue to doubt my own 
competence to understand it rather than ascribe to Mr. 
Thomson an hypothesis apparently so irrelevant to the 
facts which it professes to explain. 

Another difficulty is the following : Mr. Thomson will 
have seen that I have recorded certain winter measure- 
ments made on the Mer de Glace, and that these mea- 
surements show not only that the ice moves at that period 
of the year, but that it exhibits those characteristics 
of motion from which its plasticity has been inferred ; 
the velocity of the central portions of the glacier being in 
round numbers double the velocity of those near the sides. 
Had there been any necessity for it, this ratio might have 
been augmented by placing the side-stakes closer to the 
walls of the glacier. Considering the extreme coldness of 
the weather which preceded these measurements, it is a 
moderate estimate to set down the temperature of the 
ice in which my stakes were fixed at 5 Cent, below zero. 

Let us now endeavour to estimate the pressure existing 
at the portion of the glacier where these measurements 
were made. The height of the Montanvert above the sea- 
level is, according to Prof. Forbes, 6300 feet ; that of the 
Col du Geant, which is the summit of the principal tribu- 
tary of the Mer de Glace, is 11,146 feet : deducting the 
former from the latter, we find the height of the Col du 
Geant above the Montanvert to be 4846 feet. 

Now, according to Mr. Thomson's theory and his bro- 
ther's experiments, the melting point of ice is lowered 
'0075 Centigrade for every atmosphere of pressure ; and 
one atmosphere being equivalent to the pressure of about 
9 thirty-three feet of water, we shall not be over the truth if 
we take the height of an equivalent column of glacier-ice, 
of a compactness the mean of those which it exhibits upon 



344 ACTUAL PRESSUEE INSUFFICIENT. 

the Col du Geant and at the Montanvert respectively, at 
forty feet. The compactness of glacier ice is, of course, 
affected by the air-bubbles contained within it. 

If, then, the pressure of forty feet of ice lower the melting 
point "0075 Centigrade, it follows that the pressure of a 
column 4846 feet high will lower it nine-tenths of a degree 
Centigrade. Supposing, then, the unimpeded thrust of the 
whole glacier, from the Col- du Oeant doiunwards, to be 
exerted on the ice at the Montanvert ; or, in other words, 
supposing the bed of the glacier to be absolutely smooth 
and every trace of friction abolished, the utmost the 
pressure thus obtained could perform would be to lower 
the melting point of the Montanvert ice by the quantity 
above mentioned. Taking into account the actual state 
of things, the friction of the glacier against its sides 
and bed, the opposition which the three tributaries en- 
counter in the neck of the valley at Trelaporte, the 
resistance encountered in the sinuous valley through 
which it passes; and finally, bearing in mind the com- 
paratively short length of the glacier, which has to 
bear the thrust, and oppose the latter by its own friction 
merely ; I think it will appear evident that the ice at 
the Montanvert cannot possibly have its melting point 
lowered by pressure more than a small fraction of a de- 
gree, 

The ice in which my stakes were fixed being 5 Centi- 
grade, according to Mr. Thomson's calculation and his 
brother's experiments, it would require 667 atmospheres of 
pressure to liquefy it ; in other words, it would require the 
unimpeded pressure of a column of glacier-ice 26,680 feet 
high. Did Mont Blanc rise to two and a half times its 
present height above the Montanvert, and were the latter 
place connected with the summit of the mountain by a 
continuous glacier with its bed absolutely smooth, the pres- 
sure at the Montanvert would be rather under that neces- 



MEASUREMENTS APPLY TO SURFACE. 345 

sary to liquefy the ice on which my winter observations 
were made. 

If it be urged that, though the temperature near the 
surface may be several degrees below the freezing point, 
the great body of the glacier does not share this tempera- 
ture, but is, in all probability, near to 32, my reply 
is simple. I did not measure the motion of the ice in the 
body of the glacier ; nobody ever did ; my measurements 
refer to the ice at and near the surface, and it is this ice 
which showed the plastic deportment which the measure- 
ments reveal. 

Such, then, are some of the considerations which prevent 
me from accepting the theory of Mr. Thomson, and I trust 
they will acquit me of all desire to make his theory co- 
operate with my views. I am, however, far from con- 
sidering his deduction the less important because of its 
failing to account for the phenomena of glacier motion. 



346 



POSSIBLE MOULDING OF ICE. 



THE PRESSURE-THEORY OF GLACIER-MOTION. 

(22.) 

BROADLY considered, two classes of facts are presented to 
the glacier-observer ; the one suggestive of viscosity, and 
the other of the reverse. The former are seen where pres- 
sure comes into play, the latter where tension is operative. 
By pressure ice can be moulded to any shape, while the 
same ice snaps sharply asunder if subjected to tension. 
Were the result worth the labour, ice might be moulded 
into vases or statuettes, bent into spiral bars, and, I doubt 
not, by the proper application of pressure, a rope of ice 
might be formed and coiled into a knot. But not one of 
these experiments, though they might be a thousandfold 
more striking than any ever made upon a glacier, would 
in the least demonstrate that ice is really a viscous body. 

I have here stated what I believe to be feasible. Let 
me now refer to the experiments which have been actually 

A B 






Fig. 30. 



made in illustration of this point. Two pieces of seasoned 
box-wood had corresponding cavities hollowed in them, so 
that, when one was placed upon the other, a lenticular 



ACTUAL MOULDING OF ICE. 



347 




space was enclosed. A and B, Fig. 30, represent the 
pieces of box-wood with the cavities in plan : c represents 
their section when they are placed upon each other. 

A sphere of ice rather more than sufficient to fill the 
lenticular space was placed between the pieces of wood 
and subjected to the action of a small hydraulic press. 
The ice was crushed, but the crushed fragments soon re- 
attached themselves, and, in a few seconds, a lens of com- 
pact ice was taken from the mould. 

This lens was placed in a cylindrical cavity hollowed out 
in another piece of box-wood, and represented at c, Fig. 31 ; 
and a flat piece of the wood was placed 
over the lens as a cover, as at D. On sub- 
jecting the whole to pressure, the lens broke, 
as the sphere had done, but the crushed mass 
soon re-established its continuity, and in less 
than half a minute a compact cake of ice 
was taken from the mould. 

In the following experiment the ice was 
subjected to a still severer test : A hemi- 
spherical cavity was formed in one block of 
box- wood, and upon a second block a hemi- Fig 3L 
spherical protuberance was turned, smaller than the cavity, 
so that, when the latter was placed in the former, a space 
of a quarter of an inch existed between the two. Fig. 32 
represents a section of the two G 
pieces of box-wood ; the brass pins 

a, 6, fixed in the slab G H, and #< r^F""" 

entering suitable apertures in the ];. 

mould I K, being intended to 
keep the two surfaces concentric, i w-<(<mr <* 
A lump of ice being placed in pig. 32. 

the cavity, the protuberance was brought down upon it, 
and the mould subjected to hydraulic pressure : after a 
short interval the ice was taken from the mould as a 




348 



ICE MOULDED TO CUPS AND RINGS. 





smooth compact cup, its crushed particles having reunited, 
and established their continuity. 

To make these results more applicable to the bending of 
glacier-ice, the following experiments were made : A block 
of box-wood, M, Fig. 33, 4 inches long, 3 wide, and 3 deep, 
had its upper surface slightly curved, 
and a groove an inch wide, and about 
an inch deep, worked into it. A corre- 
sponding plate was prepared, having 
its under surface part of a convex cy- 
linder, of the same curvature as the 
concave surface of the former piece. 
When the one slab was placed upon 
the other, they presented the appear- 
ance represented in section at N. A 
straight prism of ice 4 inches long, an 
inch wide, and a little more than an 
inch in depth, was placed in the groove ; the upper slab 
was placed upon it, and the whole was subjected to the 
hydraulic press. The prism broke, but, the quantity of ice 
being rather more than sufficient to fill the groove, the 
pressure soon brought the fragments together and re-esta- 
blished the continuity of the ice. After a few seconds it 
was taken from the mould a bent bar of ice. This bar 
was afterwards passed through three other moulds of 
gradually augmenting curvature, and was taken from 
the last of them a semi-ring of compact ice. 

The ice, in changing its form from that of one mould to 
that of another, was in every instance broken and crushed 
by the pressure ; but suppose that instead of three moulds 
three thousand had been used ; or, better still, suppose the 
curvature of a single mould to change by extremely slow 
degrees ; the ice would then so gradually change its form 
that no rude rupture would be apparent. Practically the 
ice would behave as a plastic substance; and indeed 



SOFTNESS OF ICE DEFINED. 349 

this plasticity has been contended for by M. Agassiz, in 
opposition to the idea of viscosity. As already stated, the 
ice, bruised, and flattened, and bent in the above experi- 
ments, was incapable of being sensibly stretched ; it was 
plastic to pressure but not to tension. 

A quantity of water was always squeezed out of the 
crushed ice in the above experiments, and the bruised 
fragments were intermixed with this and with air. Minute 
quantities of both remained in the moulded ice, and thus 
rendered it in some degree turbid. Its character, how- 
ever, as to continuity may be inferred from the fact that 
the ice-cup, moulded as described, held water without the 
slightest visible leakage. 

Ice at 32 may, as already stated, be crushed with 
extreme facility, and glacier-ice with still more readiness 
than lake-ice : it may also be scraped with a knife with 
even greater facility than some kinds of chalk. In com- 
parison with ice at 100 below the freezing point, it might 
be popularly called soft. But its softness is not that of 
paste, or wax, or treacle, or lava, or honey, or tar. It is the 
softness of calcareous spar in comparison with that of rock- 
crystal; and although the latter is incomparably harder 
than the former, I think it will be conceded that the term 
viscous would be equally inapplicable to both. My object 
here is clearly to define terms, and not permit physical 
error to lurk beneath them, How far this ice, with a soft- 
ness thus defined, when subjected to the gradual pressures 
exerted in a glacier, is bruised and broken, and how far the 
motion of its parts may approach to that of a truly viscous 
body under pressure, I do not know. The critical point 
here is that the ice changes its form, and preserves its 
continuity, during its motion, in virtue of external force. 
It remains continuous whilst it moves, because its par- 
ticles are kept in juxtaposition by pressure, and when 
this external prop is removed, and the ice, subjected to 



350 PRESSUEE AND TENSION. 

tension, has to depend solely upon the mobility of its 
own particles to preserve its continuity, the analogy with 
a viscous body instantly breaks down.* 

* " Imagine," writes Professor Forbe-s, " a long narrow trough or canal, 
stopped at both ends and filled to a considerable depth with treacle, honey, 
tar, or any such viscid fluid. Imagine one end of the trough to give way, 
the bottom still remaining horizontal : if the friction of the fluid against the 
bottom be greater than the friction against its own particles, the upper 
strata will roll over the lower ones, and protrude in a convex slope, which 
will be propagated backwards towards the other or closed end of the 
trough. Had the matter been quite fluid the whole would have run out, 
and spread itself on a level : as it is, it assumes precisely the conditions 
which we suppose to exist in a glacier." This is perfectly definite, and 
my equally definite opinion is that no glacier ever exhibited the me- 
chanical effects implied by this experiment. 



FARADAY'S FIEST EXPERIMENT. 351 



REGELATION. 

(23.) 

I WAS led to the foregoing results by reflecting on an 
experiment performed by Mr. Faraday, at a Friday 
evening meeting of the Royal Institution, on the 7th 
of June, 1850, and described in the 'Athenaeum' and 
c Literary Gazette ' for the same month. Mr. Faraday 
then showed that when two pieces of ice, with moistened 
surfaces, were placed in contact, they became cemented 
together by the freezing of the film of water between 
them, while, when the ice was below 32 Fahr., and 
therefore dry, no effect of the kind could be produced. 
The freezing was also found to take place under water ; 
and indeed it occurs even when the water in which the 
ice is plunged is as hot as the hand can bear. 

A generalisation from this interesting fact led me to 
conclude that a bruised mass of ice, if closely confined, 
must re-cement itself when its particles are brought into 
contact by pressure; in fact, the whole of the experi- 
ments above recorded immediately suggested themselves 
to my mind as natural deductions from the principle esta- 
blished by Faraday. A rough preliminary experiment 
assured me that the deductions would stand testing ; and 
the construction of the box-wood moulds was the conse- 
quence. We could doubtless mould many solid substances 
to any extent by suitable pressure, breaking the attach- 
ment of their particles, and re-establishing a certain con- 
tinuity by the mere force of cohesion. With such sub- 
stances, to which we should never think of applying the 
term viscous, we might also imitate the changes of form to 
which glaciers are subject : but, superadded to the mere 
cohesion which here comes into play, we have, in the case of 



352 RECENT EXPERIMENTS OF FARADAY. 

ice, the actual regelation of the severed surfaces, and conse- 
quently a more perfect solid. In the Introduction to this 
book I have referred to the production of slaty cleavage by 
pressure ; and at a future page I hope to show that the 
lamination of the ice of glaciers is due to the same cause ; 
but, as justly observed by Mr. John Ball, there is no ten- 
dency to cleave in the sound ice of glaciers ; in fact, this 
tendency is obliterated by the perfect regelation of the 
severed surfaces. 

Mr. Faraday has recently placed pieces of ice, in water, 
under the strain of forces tending to pull them apart. 
When two such pieces touch at a single point they adhere 
and move together as a rigid piece ; but a little lateral 
force carefully applied breaks up this union with a crack- 
ling noise, and a new adhesion occurs which holds the 
pieces together in opposition to the force which tends to 
divide them. Mr. James Thomson had referred regelation 
to the cold produced by the liquefaction of the pressed ice ; 
but in the above experiment all pressure is not only taken 
away, but is replaced by tension. Mr. Thomson also con- 
ceives that, when pieces of ice are simply placed together 
without intentional pressure, the capillary attraction brings 
the pressure of the atmosphere into play ; but Mr. Faraday 
finds that regelation takes place in vacuo. A true viscidity 
on the part of ice Mr. Faraday never has observed, and he 
considers that his recent experiments support the view 
originally propounded by himself, namely, that a particle 
of water on a surface of ice becomes solid when placed 
between two surfaces, because of the increased influence 
due to their joint action. 



HOW CRYSTALS ARE "NURSED." 353 



CRYSTALLIZATION AND INTERNAL 
LIQUEFACTION 

(24.) 

IN the Introduction to this book I have briefly referred to 
the force of crystallization. To permit this force to exer- 
cise its full influence, it must have free and unimpeded 
action ; a crystal, for instance, to be properly built, ought 
to be suspended in the middle of the crystallizing solu- 
tion, so that the little architects can work all round it ; 
or if placed upon the bottom of a vessel, it ought to be 
frequently turned, so that all its facets may be succes- 
sively subjected to the building process. In this way 
crystals can be nursed to an enormous size. But where 
other forces mingle with that of crystallization, this har- 
mony of action is destroyed ; the figures, for example, 
that we see upon a glass window, on a frosty morning, 
are due to an action compounded of the pure crystalline 
force and the cohesion of the liquid to the window-pane. 
A more regular effect is obtained when the freezing par- 
ticles are suspended in still air, and here they build them- 
selves into those wonderful figures which Dr. Scoresbyhas 
observed in the Polar Regions, Mr. Glaisher at Greenwich, 
and I myself on the summit of Monte Rosa and elsewhere. 
Not only however in air, but in water also, figures of 
great beauty are sometimes formed. Harrison's excellent 
machine for the production of artificial ice is, I suppose, 
now well known ; the freezing being effected by carrying 
brine, which had been cooled by the evaporation of ether, 
round a series of flat tin vessels containing water. The 
latter gradually freezes, and, on watching those vessels 
while the action was proceeding very slowly, I have seen 
little six-rayed stars of thin ice forming, and rising to the 

A A 



354 DISSECTION OF ICE BY SUNBEAM. 

surface of the liquid. I believe the fact was never before 
observed, but it would be interesting to follow it up, and 
to develop experimentally this most interesting case of 
crystallization. 

The surface of a freezing lake presents to the eye of the 
observer nothing which could lead him to suppose that 
a similar molecular architecture is going on there. Still 
the particles are undoubtedly related to each other in this 
way ; they are arranged together on this starry type. And 
not only is this the case at the surface, but the largest 
blocks of ice which reach us from Norway and the Wen- 
ham Lake are wholly built up in this way. We can re- 
veal the internal constitution of these masses by a reverse 
process to that which formed them ; we can send an agent 
into the interior of a mass of ice which shall take down 
the atoms which the crystallizing forces had set up. 
This agent is a solar beam ; with which it first occurred 
to me to make this simple experiment in the autumn of 
1857. I placed a large converging lens in the sunbeams 
passing through a room, and observed the place where the 
rays were brought to a focus behind the lens ; then shad- 
ing the lens, I placed a clear cube of ice so that the point 
of convergence of the rays might fall within it. On re- 
moving the screen from the lens, a cone of sunlight went 
through the cube, and along the course of the cone the 
ice became studded with lustrous spots, evidently formed 
by the beam, as if minute reflectors had been sud- 
denly, established within the mass, from which the light 
flashed when it met them. On examining the cube after- 
wards I found that each of these spots was surrounded by a 
liquid flower of six petals ; such flowers were distributed in 
hundreds through the ice, being usually clear and detached 
from each other, but sometimes crowded together into 
liquid bouquets, through which, however, the six-starred 
element could be plainly traced. At first the edges of the 



LIQUID FLOWEES IN ICE. 355 

leaves were unbroken curves, but when the flowers expanded 
under a long-continued action, the edges became serrated. 
When the ice was held at a suitable angle to the solar 
beams, these liquid blossoms, with their central spots 
shining more intensely than burnished silver, presented 
an exhibition of beauty not easily described. I have given 
a sketch of their appearance in Fig. 34. 




Fig. 34. 

I have here to direct attention to an extremely curious 
fact. On sending the sunbeam through the transparent 
ice, I often noticed that the appearance of the lustrous 
spots was accompanied by an audible clink, as if the ice 
were ruptured inwardly. But there is no ground for 
assuming such rupture, and on the closest examination 
no flaw is exhibited by the ice. What then can be the 
cause of the noise ? I believe the following considerations 
will answer the question : 

Water always holds a quantity of air in solution, the 
diffusion of which through the liquid, as proved by M. 
Donny, has an immense effect in weakening the cohesion 
of its particles ; recent experiments of my own show that 
this is also the case in an eminent degree with many 
volatile liquids. M. Donny has proved that, if water be 
thoroughly purged of its air, a long glass tube filled with 

A A 2 



356 WATER DEPRIVED OF AIR SNAPS ASUNDER. 

this liquid may be inverted, while the tenacity with which 
the water clings to the tube, and with which its particles 
cling to each other, is so great that it will remain securely 
suspended, though no external hindrance be offered to 
its descent. Owing to the same cause, water deprived of its 
air will not boil at 212 Fahr., and may be raised to a tem- 
perature of nearly 300 without boiling ; but when this 
occurs the particles break .their cohesion suddenly, and 
ebullition is converted into explosion. 

Now, when ice is formed, every trace of the air which 
the water contained is squeezed out of it ; the particles in 
crystallizing reject all extraneous matter, so that in ice we 
have a substance quite free from the air, which is never 
absent in the case of water ; it therefore follows that if we 
could preserve the water derived from the melting of ice 
from contact with the atmosphere, we should have a liquid 
eminently calculated to show the effects described by M. 
Donny. Mr. Faraday has proved by actual experiment 
that this is the case. 

Let us apply these facts to the explanation of the clink 
heard in my experiments. On sending a sunbeam through 
ice, liquid cavities are suddenly formed at various points 
within the mass, and these cavities are completely cut off 
from atmospheric contact. But the water formed by the 
melting ice is less in volume than the ice which produces 
it; the water of a cavity is not able to fill it, hence a 
vacuous space must be formed in the cell. I have 110 
doubt that, for a time, the strong cohesion between the 
walls of the cell and the drop within it augments the 
volume of the latter a little, so as to compel it to fill the 
cell; but as the quantity of liquid becomes greater the 
shrinking force augments, until finally the particles snap 
asunder like a broken spring. At the same moment a 
lustrous spot appears, which is a vacuum, and simul- 
taneously with the appearance of this vacuum the clink 



FIGURES IN ICE; VACUOUS SPOTS. 357 

was always heard. Multitudes of such little explosions 
must be heard upon a glacier when the strong summer 
sun shines upon it, the aggregate of which must, I think, 
contribute to produce the "crepitation" noticed by M. 
Agassiz, and to which I have already referred. 

In Plate VI. of the Atlas which accompanies the ' Sys- 
teme Glaciaire ' of M. Agassiz, I notice drawings of figures 
like those I have described, which he has observed in glacier- 
ice, and which were doubtless produced by direct solar radia- 
tion. I have often myself observed figures of exquisite 
beauty formed in the ice on the surface of glacier-pools by 
the morning sun. In some cases the spaces between the 
leaves of the liquid flowers melt partially away, and leave 
the central spot surrounded by a crimped border ; sometimes 
these spaces wholly disappear, and the entire space bounded 
by the lines drawn from point to point of the leaves be- 
comes liquid, thus forming perfect hexagons. The crimped 
borders exhibit different degrees of serration, from the 
full leaves themselves to a gentle undulating line, which 
latter sometimes merges into a perfect circle. In the ice 
of glaciers, I have seen the internal liquefaction ramify 
itself like sprigs of myrtle ; in the same ice, and par- 
ticularly towards the extremities of the glacier, disks innu- 
merable are also formed, consisting of flat round liquid 
spaces, a bright spot being usually associated with each. 
These spots have been hitherto mistaken for air-bubbles ; 
but both they and the lustrous disks at the centres of the 
flowers are vacuous. I proved them to be so by plunging 
the ice containing them into hot water, and watching 
what occurred when the walls of the cells were dissolved, 
and a liquid connexion established between them and the 
atmosphere. In all cases they totally collapsed, and no 
trace of air rose to the surface of the warm water. 

No matter in what direction a solar beam is sent through 
lake-ice, the liquid flowers are all formed parallel to the 



358 CONSTITUTION OF GKLACIEK-ICE. 

surface of freezing. The beam may be sent parallel, per- 
pendicular, or oblique to this surface; the flowers are 
always formed in the same planes. Every line perpendi- 
cular to the surface of a frozen lake is in fact an axis of 
symmetry, round which the molecules so arrange them- 
selves, that, when taken down by the delicate fingers of the 
sunbeam, the six-leaved liquid flowers are the result. 

In the ice of glaciers we have no definite planes of 
freezing. It is first snow, which has been disturbed by 
winds while falling, and whirled, and tossed about by the 
same agency after it has fallen, being often melted, satur- 
ated with its own water, and refrozen : it is cast in shattered 
fragments down cascades, and reconsolidated by pressure 
at the bottom. In ice so formed and subjected to such 
mutations, definite planes of freezing are, of course, out of 
the question. 

The flat round disks and vacuous spots to which I have 
referred come here to our aid, and furnish us with an entirely 
new means of analysing the internal constitution of a glacier. 
When we examine a mass of glacier-ice which contains these 
disks, we find them lying in all imaginable planes ; not 
confusedly, however closer examination shows us that the 
disks are arranged in groups, the members of each group 
being parallel to a common plane, but the parallelism 
ceases when different groups are compared. The effect is 
exactly what would be observed, supposing ordinary lake- 
ice to be broken up, shaken together, and the confused 
fragments regelated to a compact continuous mass. In 
such a jumble the original planes of freezing would lie in 
various directions ; but no matter how compact or how 
transparent ice thus constituted might appear, a solar 
beam would at once reveal its internal constitution by 
developing the flowers parallel to the planes of freezing of 
the respective fragments. A sunbeam sent through glacier- 
ice always reveals the flowers in the planes of the disks, so 



VACUOUS CELLS MISTAKEN FOR AIR-CELLS. 359 

that the latter alone at once informs us of its crystalline 
constitution. 

Hitherto, as I have said, these disks have been mistaken 
for bubbles containing air, and their flattening has been 
ascribed to the pressure to which they have been subjected. 
M. Agassiz thus refers to them : " The air-bubbles un- 
dergo no less curious modifications. In the neighbourhood of 
the neve, where they are most numerous, those which one 
sees on the surface are all spherical or ovoid, but by 
degrees they begin to be flattened, and near the end of the 
glacier there are some that are so flat that they might be 
taken for fissures when seen in profile. The drawing 
represents a piece of ice detached from the gallery of infil- 
tration. All the bubbles are greatly flattened. But what 
is most extraordinary is, that, far from being uniform, the 
flattening is different in each fragment ; so that the bubbles, 
according to the face which they offer, appear either very 
broad or very thin." This description of glacier-ice is 
correct : it agrees with the statements of all other obser- 
vers. But there are two assumptions in the description 
which must henceforth be given up ; first, the bubbles 
seen like fissures in profile are not air-bubbles at all, but 
vacuous spots, which the very constitution of ice renders 
a necessary concomitant of its inward melting; secondly, 
the assumption that the bubbles have been flattened by 
pressure must be abandoned; for they are found, and 
may be developed at will, in lake-ice on which no pres- 
sure has been exerted. 

But these remarks dispose only of a certain class of cells 
contained in glacier-ice. Besides the liquid disks and 
vacuous spots, there are innumerable true bubbles en- 
tangled in the mass. These have also been observed and 
described by M. Agassiz ; and Mr. Huxley has also given 
us an accurate account of them. M. Agassiz frequently 
found air and water associated in the same cell. Mr. 



360 CELLS OF AIR AND WATER. 

Huxley found no exception to the rule : in each case the 
bubble of air was enclosed in a cell which was also partially 
filled with water. He supposes that the water may be that 
of the originally-melted snow which has been carried down 
from the neve unfrozen. This hypothesis is worthy of a 
great deal more consideration than I have had time to give 
to it, and I state it here in the hope that it will be duly 
examined. 

My own experience of these associated air and water 
cells is derived almost exclusively from lake-ice, in which I 
have often observed them in considerable numbers. In 
examining whether the liquid contents had ever been 
frozen or not, I was guided by the following considerations. 
If the air be that originally entangled in the solid, it will 
have the ordinary atmospheric density at least ; but if it be 
due to the melting of the walls of the cell, then the water- 
so formed being only eight-ninths of that of the ice which 
produced it, the air of the bubble must be rarefied. I 
suppose I have made a hundred different experiments upon 
these bubbles to determine whether the air was rarefied or 
not, and in every case found it so. Ice containing the 
bubbles was immersed in warm water, and always, when 
the rigid envelope surrounding a bubble was melted away, 
the air suddenly collapsed to a fraction of its original 
dimensions. I think I may safely affirm that, in some 
cases, the collapse reduced the bubbles to the thousandth 
part of their original volume. From these experiments I 
should undoubtedly infer, that in lake-ice at least, the 
liquid of the cells is produced by the melting of the ice 
surrounding the bubbles of air. 

But I have not subjected the bubbles of glacier-ice to 
the same searching examination. I have tried whether 
the insertion of a pin would produce the collapse of the 
bubbles, but it did not appear to do so. I also made a few 
experiments at Rosenlaui, with warm water, but the result 



"LIQUID LIBERTY." 361 

was not satisfactory. That ice melts internally at the 
surfaces of the bubbles is, I think, rendered certain by my 
experiments, but whether the water-cells of glacier-ice 
are entirely due to such melting, subsequent observers 
will no doubt determine. 

I have found these composite bubbles at all parts of 
glaciers ; in the ice of the moraines, over which a protective 
covering had been thrown ; in the ice of sand-cones, after 
the removal of the superincumbent debris ; also in ice 
taken from the roofs of caverns formed in the glacier, and 
which the direct sunlight could hardly by any possibility 
attain. That ice should liquefy at the surface of a cavity 
is, I think, in conformity with all we know concerning the 
physical nature of heat. Regarding it as a motion of the 
particles, it is easy to see that this motion is less restrained 
at the surface of a cavity than in the solid itself, where 
the oscillation of each atom is controlled by the particles 
which surround it ; hence liquid liberty, if I may use the 
term, is first attained at the surface. Indeed I have proved 
by experiment that ice may be melted internally by heat 
which has been conducted through its external portions 
without melting them. These facts are the exact com- 
plements of those of " regelation ; " for here, two moist sur- 
faces of ice being brought into close contact, their liquid 
liberty is destroyed and the surfaces freeze together. 



362 MOULIN ON GKINDELWALD GLACIER 



THE MOULINS. 
(25.) 

THE first time I had an opportunity of seeing these 
remarkable glacier-chimneys, was in the summer of 1856, 
upon the lower glacier of Grindelwald. Mr. Huxley was 
my companion at the time, and on crossing the so-called 
Eismeer we heard a sound resembling the rumble of distant 
thunder, which proceeded from a perpendicular shaft 
formed in the ice, and into which a resounding cataract 
discharged itself. The tube in fact resembled a vast organ- 
pipe, whose thunder-notes were awakened by the concussion 
of the falling water, instead of by the gentle flow of a 
current of air. Beside the shaft our guide hewed steps, on 
which we stood in succession, and looked into the tre- 
mendous hole. Near the first shaft was a second and 
smaller one, the significance of which I did not then 
understand ; it was not more than 20 feet deep, but 
seemed filled with a liquid of exquisite blue, the colour 
being really due to the magical shimmer from the walls 
of the moulin, which was quite empty. As far as we 
could see, the large shaft was vertical, but on dropping a 
stone into it a shock was soon heard, and after a succession 
of bumps, which occupied in all seven seconds, we heard the 
stone no more. The depth of the moulin could not be thus 
ascertained, but we soon found a second and still larger one 
which gave us better data. A stone dropped into this de- 
scended without interruption for four seconds, when a con- 
cussion was heard ; and three seconds afterwards the final 
shock was audible : there was thus but a single interruption 
in the descent. Supposing all the acquired velocity to have 
been destroyed by the shock, by adding the space passed 



DEPTH OF SHAFT. 363 

over by the stone in four and in three seconds respectively, 
and making allowance for the time required by the sound 
to ascend from the bottom, we find the depth of the shaft 
to be about 345 feet. There is, however, no reason to 
suppose that this measures the depth of the glacier at 
the place referred to. These shafts are to be found in 
almost all great glaciers ; they are very numerous in the 
Unteraar Glacier, numbers of them however being empty. 
On the Mer de Glace they are always to be found in the 
region of Trelaporte, one of the shafts there being, par 
excellence, called the Grand Moulin. Many of them also 
occur on the Glacier de Lechaud. 

As truly observed by M. Agassiz, these moulins occur 
only at those parts of the glacier which are not much rent 
by fissures, for only at such portions can the little rills 
produced by superficial melting collect to form streams 
of any magnitude. The valley of unbroken ice formed in 
the Mer de Glace near Trelaporte is peculiarly favourable 
for the collection of such streams ; we see the little rills 
commencing, and enlarging by the contributions of others, 
the trunk-rill pouring its contents into a little stream 
which stretches out a hundred similar arms over the sur- 
face of the glacier. Several such streams join, and finally 
a considerable brook, which receives the superficial drainage 
of a large area, cuts its way through the ice. 

But although this portion of the glacier is free from 
those long-continued and permanent strains which, having 
once rent the ice, tend subsequently to widen the rent and 
produce yawning crevasses, it is not free from local strains 
sufficient to produce cracks which penetrate the glacier to 
a great depth. Imagine such a crack intersecting such 
a glacier-rivulet as we have described. The water rushes 
down it, and soon scoops a funnel large enough to engulf 
the entire stream. The moulin is thus formed, and, as the 
ice moves downward, the sides of the crack are squeezed 



364 MOULINS EXPLAINED. 

together and regelated, the seam which marks the line 
of junction being in most cases distinctly visible. But 
as the motion continues, other portions of the glacier come 
into the same state of strain as that which produced the 
first crack; a second one is formed across the stream, 
the old shaft is forsaken, and a new one is hollowed out, 
in which for a season the cataract plays the thunderer. I 
have in some cases counted the forsaken shafts of six 
old moulins in advance of an active one. Not far from 
the Grand Moulin of the Mer de Glace in 1857 there was 
a second empty shaft, which evidently communicated by 
a subglacial duct with that into which the torrent was 
precipitated. Out of the old orifice issued a strong cold 
blast, the air being manifestly impelled through the duct 
by the falling water of the adjacent moulin. 

These shafts are always found in the same locality ; the 
portion of the Mer de Glace to which I have referred is 
never without them. Some of the guides affirm that they 
are motionless; and a statement of Prof. Forbes has led 
to the belief that this was also his opinion.* M. Agassiz, 
however, observed the motion of some of these shafts 
upon the glacier of the Aar ; and when on the spot in 
1857, I was anxious to decide the point by accurate 
measurements with the theodolite. 

My friend Mr. Hirst took charge of the instrument, and 
on the 28th of July I fixed a single stake beside the Grand 
Moulin, in a straight line between a station at Trelaporte 
and a well-defined mark on the rock at the opposite side 
of the valley. On the 31st, the displacement of the stake 
amounted to 50 inches, and on the 1st of August it had 
moved 74^ inches the moulin, to all appearance, occupy- 
ing throughout the same position with regard to the stake. 

* " Every year, and year after year, the watercourses follow the same 
lines of direction their streams are precipitated into the heart of the 
glacier by vertical funnels, called ' moulins,' at the very same points." 
Forbes's Fourth Letter upon Glaciers : ' Occ. Pap.,' p. 29. 



MOTION OF THE MOULINS. 365 

To render this certain, moreover we subsequently drove two 
additional stakes into the ice, thus enclosing the mouth 
of the shaft in a triangle. On the 8th of August the 
displacements were measured and gave the following 
results : 

Total Motion. 

First (old) stake 198 inches. 

Second (new) do 123 

Third 124 

The old stake had been fixed for 11 days, and its daily 
motion which ivas also that of the moulin averaged 
18 inches a day. Hence the moulins share the general 
motion of the glacier, and their apparent permanence is 
not, as has been alleged, a proof of the semi-fluidity of the 
glacier, but is due to the breaking of the ice as it passes 
the place of local strain. 

Wishing to obtain some estimate as to the depth of 
the ice, Mr. Hirst undertook the sounding of some of the 
moulins upon the Glacier de Lechaud, making use of a 
tin vessel filled with lumps of lead and iron as a weight. 
The cord gave way and he lost his plummet. To measure 
the depth of the Grand Moulin, we obtained fresh cord 
from Chamouni, to which we attached a four-pound weight. 
Into a cavity at the bottom of the weight we stuffed a quan- 
tity of butter, to indicate the nature of the bottom against 
which the weight might strike. The weight was dropped 
into the shaft, and the cord paid out until its slackening 
informed us that the weight had come to rest ; by shaking 
the string, however, and walking round the edge of the 
shaft, the weight was liberated, and sank some distance fur- 
ther. The cord partially slackened a second time, but the 
strain still remaining was sufficient to render it doubtful 
whether it was the weight or the action of the falling water 
which produced it. We accordingly paid out the cord to 
the end, but, on withdrawing it, found that the greater part 
of it had been coiled and knotted up by the falling water. 



366 DEPTH OF "GRAND MOULIN" SOUGHT. 

We uncoiled, and sounded again. At a depth of 132 feet 
the weight reached a ledge or protuberance of ice, and by 
shaking and lifting it, it was caused to descend 31 feet more. 
A depth of 163 feet was the utmost we could attain to. 
We sounded the old moulin to a depth of 90 feet ; while a 
third little shaft, beside the large one, measured only 
18 feet in depth. We could see the water escape from it 
through a lateral canal at its bottom, and doubtless the 
water of the Grand Moulin found a similar exit. There 
was no trace of dirt upon the butter, which might have 
indicated that we had reached the bed of the glacier. 




DIRT-BANDS OF THE MER DE GLACE, AS SEEN FROM A POINT 
NEAR THE FLEGERE. 



FIG. 35. 



To face p. 367. 



DIET-BANDS FROM THE FLEG-ERE. 367 

DIRT-BANDS OF THE MER, DE GLACE. 

(26.) 

THESE bands were first noticed by Prof. Forbes on the 24th 
of July, 1842, and were described by him in the following 
words : {C My eye was caught by a very peculiar appear- 
ance of the surface of the ice, which I was certain that I 
now saw for the first time. It consisted of nearly hyper- 
bolic brownish bands on the glacier, the curves pointing 
downwards, and the two branches mingling indiscriminately 
with the moraines, presenting an appearance of a succession 
of waves some hundred feet apart." * From no single point 
of view hitherto attained can all the Dirt-Bands of the 
Mer de Glace be seen at once. To see those on the 
terminal portion of the glacier, a station ought to be chosen 
on the opposite range of the Brevent, a few hundred yards 
beyond the Croix de la Flegere, where we stand exactly 
in front of the glacier as it issues into the valley of Cha- 
mouni. The appearance of the bands upon the portion 
here seen is represented in Fig. 35. 

It will be seen that the bands are confined to one side 
of the glacier, and either do not exist, or are obliterated by 
the debris, upon the other side. The cause of the accumu- 
lation of dirt on the right side of the glacier is, that no less 
than five moraines are crowded together at this side. In 
the upper portions of the Mer de Glace these moraines are 
distinct from each other ; but in descending, the successive 
engulfments and disgorgings of the blocks and dirt have 
broken up the moraines ; and at the place now before us the 
materials which composed them are strewn confusedly on 
' the right side of the glacier. The portion of the ice on 
which the dirt-bands appear is derived from the Col du 
* ' Travels,' page 162. 



368 DIET-BANDS FKOM LES CHAKMOZ. 

Geant. They do not quite extend to the end of the glacier, 
being obliterated by the dislocation of the ice upon the 
frozen cascade of Des Bois. 

Let us now proceed across the valley of Chamouni to 
the Montanvert ; where, climbing the adjacent heights to 
an elevation of six or eight hundred feet above the hotel, 
we command a view of the Mer de Glace, from Trelaporte 
almost to the commencement of the Glacier des Bois. It 
was from this position that Professor Forbes first observed 
the bands. Fifteen, sixteen, and seventeen years later I 
observed them from the same position. The number of 
bands which Professor Forbes counted from this position was 
eighteen, with which my observations agree. The entire 
series of bands which I observed, with the exception of 
one or two, must have been the successors of those observed 
by Professor Forbes ; and my finding the same number 
after an interval of so many years proves that the bands 
must be due to some regularly recurrent cause. Fig. 36 
represents the bands as seen from the heights adjacent to 
the Montanvert. 

I would here direct attention to an analogy between a 
glacier and a river, which may be observed from the 
heights above the Montanvert, but to which no reference, 
as far as I know, has hitherto been made. When a river 
meets the buttress of a bridge, the water rises against it, 
and, on sweeping round it, forms an elevated ridge, be- 
tween which and the pier a depression occurs which varies 
in depth with the force of the current. This effect is 
shown by the Mer de Glace on an exaggerated scale. 
Sweeping round Trelaporte, the ice pushes itself beyond 
the promontory in an elevated ridge, from which it drops 
by a gradual slope to the adjacent wall of the valley, 
thus forming a depression typified by that already alluded 
to. A similar effect is observed at the opposite side of the 
glacier on turning round the Echelets ; and both combine 




DIRT-BANDS OP THE MEK DE GLACE, AS SEEN FROM 
LES CHARMOZ. 



FIG. 3(i. 



To fate p. 368. 




DIRT-BANDS OF THE HER DE GLACE, AS SEEN FROM THE 
CLEFT STATION, TRELAPORTE. 



FIG. 37. 



To face p. 369. 



FEOM THE CLEFT-STATION. 



369 



to form a kind of skew surface. A careful inspection of 
the frontispiece will detect this peculiarity in the shape of 
the glacier. 

From neither of the stations referred to do we obtain 
any clue to the origin of the dirt-bands. A stiff but 
pleasant climb will place us in that singular cleft in the 
cliffy mountain-ridge which is seen to the right of the 
frontispiece ; and from it we easily attain the high plat- 
form of rock immediately to the left of it. We stand here 
high above the promontory of Trelaporte, and occupy the 
finest station from which the Mer de Glace and its tribu- 
taries can be viewed. From this station we trace the dirt- 
bands over most of the ice that we have already scanned, 
and have the further advantage of being able to follow 
them to their very source. 

This source is the grand ice-cascade which descends in a 
succession of precipices from the plateau of the Col du 
Geant into the valley which the Glacier du Geant fills. 
We see from our present point of view that the bands 
are confined to the portion of the glacier ivhich has descended 
the cascade. Fig. 37 represents the bands as seen from 
the Cleft-station above Trelaporte. 

We are now however at such a height above the glacier 
and at such a distance from the base of the cascade, that we 
can form but an imperfect notion of the true contour of the 
surface. Let us therefore descend, and walk up the Glacier 
du Geant towards the cascade. At first our road is level, 
but we gradually find that at certain intervals we have to 
ascend slopes which follow each other in succession, each 
being separated from its neighbour by a space of compara- 
tively level ice. The slopes increase in steepness as we 
ascend ; they are steepest, moreover, on the right-hand 
*ide of the glacier, where it is bounded by that from the 
Periades, and at length we are unable to climb them without 
the aid of an axe. Soon afterwards the dislocation of the 

B B 



370 SNOW-BANDS ON THE GLACIER DU GEANT. 

glacier becomes considerable ; we are lost in the clefts and 
depressions of the ice, and are unable to obtain a view 
sufficiently commanding to subdue these local appearances 
and convey to us the general aspect. We have at all events 
satisfied ourselves as to the existence, on the upper portion 
of the glacier, of a succession of undulations which sweep 
transversely across it. The term " wrinkles," applied to 
them by Prof. Forbes, is highly suggestive of the appear- 
ance which they present. 

From the Cleft-station bands of snow may also be seen 
partially crossing the glacier in correspondence with the 
undulations upon its surface. If the quantity deposited 
the winter previous be large, and the heat of summer not 
too great, these bands extend quite across the glacier. 
They were first observed by Professor Forbes in 1843. In 
his Fifth Letter is given an illustrative diagram, which, 
though erroneous as regards the position of the veined 
structure, is quite correct in limiting the snow-bands to 
the Glacier du Geant proper. 

At the place where the three welded tributaries of the Mer 
de Glace squeeze themselves through the strait of Trela- 
porte, the bands undergo a considerable modification in 
shape. Near their origin they sweep across the Glacier 
du Geant in gentle curves, with their convexities directed 
downwards ; but at Trelaporte these curves, the chords 
of which a short time previous measured a thousand yards 
in length, have to squeeze themselves through a space of 
four hundred and ninety-five yards wide ; and as might be 
expected, they are here suddenly sharpened. The apex of 
each being thrust forward, they take the form of sharp 
hyperbolas, and preserve this character throughout the 
entire length of the Mer de Glace. 

I would now conduct the reader to a point from which a 
good general view of the ice cascade of the Geant is 
attainable. From the old moraine near the lake of the 



FOKBES'S EXPLANATION. 371 

Tacul we observe the ice, as it descends the fall, to be 
broken into a succession of precipices. It would appear as 
if the glacier had its back periodically broken at the sum- 
mit of the fall, and formed a series of vast chasms separated 
from each other by cliffy ridges of corresponding size. 
These, as they approach the bottom of the fall, become 
more and more toned down by the action of sun and air, 
and at some distance below the base of the cascade 
they are subdued so as to form the transverse undula- 
tions already described. These undulations are more and 
more reduced as the glacier descends; and long before 
the Tacul is attained, every sensible trace of them has 
disappeared. The terraces of the ice-fall are referred to by 
Professor Forbes in his Thirteenth Letter, where he thus 
describes them : " The ice-falls succeed one another at 
regulated intervals, which appear to correspond to the 
renewal of each summer's activity in those realms of almost 
perpetual frost, when a swifter motion occasions a more rapid 
and wholesale projection of the mass over the steep, thus 
forming curvilinear terraces like vast stairs, which appear 
afterwards by consolidation to form the remarkable pro- 
tuberant wrinkles on the surface of the Glacier du Geant." 
With regard to the cause of the distribution of the dirt in 
bands, Professor Forbes writes thus in his Third Letter : 
" I at length assured myself that it was entirely owing to 
the structure of the ice, which retains the dirt diffused by 
avalanches and the weather on those parts which are most 
porous, whilst the compacter portion is washed clean by 
the rain, so that those bands are nothing more than visible 
traces of the direction of the internal icy structure." Pro- 
fessor Forbes's theory, at that time, was that the glacier is 
composed throughout of a series of alternate segments of 
hard and porous ice, in the latter of which the dirt found a 
lodgment. I do not know whether he now retains his 
first opinion ; but in his Fifteenth Letter he speaks of 

B B 2 



372 TRANSVERSE UNDULATIONS. 

accounting for " the less compact structure of the ice 
beneath the dirt-band." 

It appears to me that in the above explanation cause has 
been mistaken for effect. The ice on which the dirt-bands 
rest certainly appears to be of a spongier character than 
the cleaner intermediate ice ; but instead of this being 
the cause of the dirt-bands, the latter, I imagine, by 
their more copious absorption of the sun's rays and the 
consequent greater disintegration of the ice, are the cause 
of the apparent porosity. I have not been able to detect 
any relative porosity in the " internal icy structure," nor am 
I able to find in the writings of Professor Forbes a de- 
scription of the experiments whereby he satisfied himself 
that this assumed difference exists. 

Several days of the summer of 1857 were devoted by 
me to the examination of these bands. I then found the 
bases and the frontal slopes of the undulations to which I 
have referred covered with a fine brown mud. These 
slopes were also, in some cases, covered with snow which 
the great heat of the weather had not been able entirely 
to remove. At places where the residue of snow was small 
its surface was exceedingly dirty so dirty indeed that it 
appeared as if peat-mould had been strewn over it ; its edges 
particularly were of a black brown. It was perfectly mani- 
fest that this snow formed a receptacle for the fine dirt 
transported by the innumerable little rills which trickled 
over the glacier. The snow gradually wasted, but it left 
its sediment behind, and thus each of the snowy bands ob- 
served by Professor Forbes in 1843, contributed to produce 
an appearance perfectly antithetical to its own. I have 
said that the frontal slopes of the undulations were thus 
covered ; and it was on these, and not in the depressions, 
that the snow principally rested. The reason of this is to 
be found in the bearing of the Glacier du Geant, which, 
looking downwards, is about fourteen degrees east of the 



INFLUENCE OF DIRECTION OF GLACIEK. 373 

meridian.* Hence the frontal slopes of the undulations 
have a northern aspect, and it is this circumstance which, 
in my opinion, causes the retention of the snow upon them. 
Irrespective of the snow, the mere tendency of the dirt to 
accumulate at the bases of the undulations would also 
produce bands, and indeed does so on many glaciers ; 
but the precision and beauty of the dirt-bands of the Mer 
de Glace are, I think, to be mainly referred to the inter- 
ception by the snow of the fine dark mud before referred 
to on the northern slopes of its undulations. 

Were the statements of some writers upon this subject 
well founded, or were the dirt-bands as drawn upon the 
map of Professor Forbes correctly shown, this explanation 
could not stand a moment. It has been urged that the dirt- 
bands cannot thus belong to a single tributary of the Mer 
de Glace ; for if they did, they would be confined to that 
tributary upon the trunk-glacier ; whereas the fact is that 
they extend quite across the trunk, and intersect the 
moraines which divide the Glacier du Geant from its 
fellow-tributaries. From my first acquaintance with the 
Mer de Glace I had reason to believe that this statement 
was incorrect ; but last year I climbed a third time to the 
Cleft-station for the purpose of once more inspecting the 
bands from this fine position. I was accompanied by 
Dr. Frankland and Auguste Balmat, and I drew the at- 
tention of both particularly to this point. Neither of them 
could discern, nor could I, the slightest trace of a dirt- 
band crossing any one of the moraines. Upon the trunk- 
stream they were just as much confined to the Glacier 
du Geant as ever. If the bands even existed east of the 

* In the large map of Professor Forbes the bearing of the valley is 
nearly sixty degrees west of the meridian ; but this is caused by the true 
north being drawn on the wrong side of the magnetic north ; thus making 
the declination easterly instead of westerly. In the map in Johnson's 
' Physical Atlas ' this mistake is corrected. 



374 BANDS DO NOT CROSS MORAINES. 

moraines, they could not be seen, the dirt on this part of 
the glacier being sufficient to mask them. 

The following interesting fact may perhaps have contri- 
buted to the production of the error referred to. Opposite 
to Trelaporte the eastern arms of the dirt-bands run so 
obliquely into the moraine of La Noire that the latter 
appears to be a tangent to them. But this moraine runs 
along the Mer de Glace, not far from its centre, and con- 
sequently the point of contact of each dirt-band with the 
moraine moves more quickly than the point of contact of 
the western arm of the same band with the side of the 
valley. Hence there is a tendency to straighten the bands ; 
and at some distance down the glacier the effect of this is 
seen in the bands abutting against the moraine of La Noire 
at a larger angle than before. The branches thus abutting 
have, I believe, been ideally prolonged across the moraines. 
On the map published by Prof. Forbes in 1843 the 
bands are shown crossing the medial moraines of the Mer de 
Glace; and they are also thus drawn on the 
map in Johnson's ' Physical Atlas ' pub- 
lished in 1849. The text is also in ac- 
cordance with the map : " Opposite to 
the Montanvert, and beyond les Echelets, 
the curved loops (dirt-bands) extend 
across the entire glacier. They are single, 
and therefore cut the medial moraine, 
though at a very slight angle." ' Travels,' 
p. 166. The italics here belong to Prof. 
Forbes. In order to help future observers 
to place this point beyond doubt, I annex, 
in Fig. 38, a portion of the map of the 
Mer de Glace taken from the Atlas re- 
ferred to. If it be compared with Fig. 35 the difference 
between Prof. Forbes and myself will be clearly seen. The 
portion of the glacier represented in both diagrams may 




ANNUAL "KINGS." 375 

be viewed from the point near the Flegere already re- 
ferred to. 

The explanation which I have given involves three con- 
siderations : The transverse breaking of the glacier on the 
cascade, and the gradual accumulation of the dirt in the 
hollows between the ridges ; the subsequent toning down 
of the ridges to gentle protuberances which sweep across 
the glacier ; and the collection of the dirt upon the slopes 
and at the bases of these protuberances. Whether the 
periods of transverse fracture are annual or not whether 
the " wrinkles " correspond to a yearly gush and whether, 
consequently, the dirt-bands mark the growth of a glacier 
as the " annual rings " mark the growth of a tree, I do not 
know. It is a conjecture well worthy of consideration ; but 
it is only a conjecture, which future observation may either 
ratify or refute. 



376 GENERAL APPEARANCE, 



THE VEINED STRUCTURE OF GLACIERS. 



THE general appearance of the veined structure may be 
thus briefly described : The ice of glaciers, especially mid- 
way between their mountain-sources and their inferior ex- 
tremities, is of a whitish hue, caused by the number of 
small air-bubbles which it contains, and which, no doubt, 
constitute the residue of the air originally entrapped in the 
interstices of the snow from which it has been derived. 
Through the general whitish mass, at some places, innumer- 
able parallel veins of clearer ice are drawn, which usually 
present a beautiful blue colour, and give the ice a laminated 
appearance. The cause of the blueness is, that the air- 
bubbles, distributed so plentifully through the general 
mass, do not exist in the veins, or only in comparatively 
small numbers. 

In different glaciers, and in different parts of the same 
glacier, these veins display various degrees of perfection. 
On the clean unweathered walls of some crevasses, and in 
the channels worn in the ice by glacier-streams, they are 
most distinctly seen, and are often exquisitely beautiful. 
They are not to be regarded as a partial phenomenon, or as 
affecting the constitution of glaciers to a small extent merely. 
A large portion of the ice of some glaciers is thus affected. 
The greater part, for example, of the Mer de Glace con- 
sists of this laminated ice ; and the whole of the Glacier of 
the Rhone, from the base of the ice-cascade downwards, is 
composed of ice of the same description. 

Those who have ascended Snowdon, or wandered among 
the hills of Cumberland, or even walked in the environs of 
Leeds, Blackburn, and other towns in Yorkshire and Lan- 
cashire, where the stratified sandstone of the district is 



GROOVES ON THE SURFACE OF GLACIERS. 377 

used for building purposes, may have observed the 
weathered edges of the slate rocks or of the building-stone 
to be grooved and furrowed. Some laminae of such rocks 
withstand the action of the atmosphere better than others, 
and the more resistant ones stand out in ridges after 
the softer parts between them have been eaten away. An 
effect exactly similar is observed where the laminated ice 
of glaciers is exposed to the action of the sun and air. 
Little grooves and ridges are formed upon its surface, the 
more resistant plates protruding after the softer material 
between them has been melted away. 

One consequence of this furrowing is, that the light dirt 
scattered by the winds over the surface of the glacier is 
gradually washed into the little grooves, thus forming fine 
lines resembling those produced by the passage of a rake 
over a sanded walk. These lines are a valuable index to 
some of the phenomena of motion. From a position on 
the ice of the Glacier du Geant a little higher up than Tre- 
laporte a fine view of these superficial groovings is obtained ; 
but the dirt-lines are not always straight. A slight power 
of independent motion is enjoyed by the separate parts into 
which a glacier is divided by its crevasses and dislocations, 
and hence it is, that, at the place alluded to, the dirt-lines 
are bent hither and thither, though the ruptures of conti- 
nuity are too small to affect materially the general direction 
of the structure. On the glacier of the Talefre I found 
these groovings useful as indicating the character of the 
forces to which the ice near the summit of the fall is sub- 
jected. The ridges between the chasms are in many cases 
violently bent and twisted, while the adjacent groovings 
enable us to see the normal position of the mass. 

The veined structure has been observed by different 
travellers; but it was probably first referred to by Sir 
David Brewster, who noticed the veins of the Mer 
de Glace on the 10th of September, 1814. I was also 



378 GUYOT'S OBSEKVATIONS. 

observed by General Sabine,* by Rendu, by Agassiz, and 
no doubt by many others ; but the first clear description 
of it was given by M. Guyot, in a communication pre- 
sented to the Geological Society of France in 1838. I quote 
the following passage from this paper : " I saw under my 
feet the surface of the entire glacier covered with regular 
furrows from one to two inches wide, hollowed out in a half 
snowy mass, and separated by protruding plates of harder 
and more transparent ice. It was evident that the mass 
of the glacier here was composed of two sorts of ice, one 
that of the furrows, snowy and more easily melted ; the 
other that of the plates, more perfect, crystalline, glassy, 
and resistant ; and that the unequal resistance which the 
two kinds of ice presented to the atmosphere was the cause 
of the furrows and ridges. After having followed them for 
several hundreds of yards, I reached a fissure twenty or thirty 
feet wide, which, as it cut the plates and furrows at right 
angles, exposed the interior of the glacier to a depth of 

* In reply to a question in connexion with this subject, General Sabine 
has favoured me with the following note : 
" MY DEAR TYNDALL, 

" It was in the summer of 1841, at the Lower Grinclelwald Glacier, 
that I first saw, and was greatly impressed and interested by examining 
and endeavouring to understand (in which I did not succeed), the veined 
structure of the ice. I do not remember when I mentioned it to Forbes, 
but it must be before 1843, because it is noticed in his book, p. 29. I had 
never observed it in the glaciers of Spitzbergen or Baffin's Bay, or in the 
icebergs of the shores and straits of Davis or Barrow. I feel the more 
confident of this, because, when I first saw the veined structure in Switzer- 
land, my Arctic experience was more fresh in my recollection, and I recol- 
lected nothing like it. 

" Veins are indeed not uncommon in icebergs, but they quite resemble 
veins in rocks, and are formed by water filling fissures and freezing into 
blue ice, finely contrasted with the white granular substance of the berg. 

" The ice of the Grindelwald Glacier (where I examined the veined 
structure) was broken up into very large masses, which by pressure had 
been upturned, so that a very poor judgment would be formed of the direc- 
tion of the veins as they existed in the glacier before it had broken up. 

" Sincerely yours, 

" Feb. 20, 1860." EDWAKD SABINE. 



FORBES'S KESEARCHES. 379 

thirty or forty feet, and gave a beautiful transverse section 
of the structure. As far as my vision could reach I saw 
the mass of the glacier composed of layers of snowy ice, 
each two of which were separated by one of the plates of 
which I have spoken, the whole forming a regularly lami- 
nated mass, which resembled certain calcareous slates." 

Previous observers had mistaken the lamination for 
stratification ; but M. Guyot not only clearly saw that they 
were different, but in the comparison which he makes he 
touches, I believe, on the true cause of the glacier-structure. 
He did not hazard an explanation of the phenomenon, and 
I believe his memoir remained unprinted. In 1841 the 
structure was noticed by Professor Forbes during his visit 
to M. Agassiz on the lower Aar Glacier, and described in 
a communication presented by him to the Koyal Society 
of Edinburgh. He subsequently devoted much time to the 
subject, and his great merit in connexion with it consists 
in the significance which he ascribed to the phenomenon 
when he first observed it, and in the fact of his having 
proved it to be a constitutional feature of glaciers in general. 

The first explanation given of those veins by Professor 
Forbes was, that they were small fissures formed in the ice 
by its motion ; that these were filled with the water of the 
melted ice in summer, which froze in winter so as to form 
the blue veins. This is the explanation given in his 
' Travels,' page 377 ; and in a letter published in the 
1 Edinburgh New Philosophical Journal,' October, 1844, it is 
re-affirmed in these words : " With the abundance of blue 
bands before us in the direction in which the differential 
motion must take place (in this case sensibly parallel to the 
sides of the glacier), it is impossible to doubt that these 
infiltrated crevices (for such they undoubtedly are) have 
this origin." This theory was examined by Mr. Huxley 
and myself in our joint paper ; but it has been since alleged 
that ours was unnecessary labour, Prof. Forbes himself 



380 FORBES'S THEOEY. 

having in his Thirteenth Letter renounced the theory, 
and substituted another in its place. The latter theory 
differs, so far as I can understand it, from the former in 
this particular, that the freezing of the water in the fissures 
is discarded, their sides being now supposed to be united 
" by the simple effects of time and cohesion." * For a 
statement of the change which his opinions have undergone, 
I would refer to the Prefatory Note which precedes the 
volume of ' Occasional Papers ' recently published by Prof. 
Forbes ; but it would have diminished my difficulty had 
the author given, in connexion with his new volume, a 
more distinct statement of his present views regarding 
the veined structure. With many of his observations 
and remarks I should agree ; with many others I cannot 
say whether I agree or not ; and there are others still 
with which I do not think I should agree : but in hardly 
any case am I certain of his precise views, excepting, 
indeed, the cardinal one, wherein he and others agree in 
ascribing to the structure a different origin from stratifi- 
cation. Thus circumstanced, my proper course, I think, 
will be to state what I believe to be the cause of the 
structure, and leave it to the reader to decide how far 
our views harmonize ; or to what extent either of them is 
a true interpretation of nature. 

Most of the earlier observers considered the structure to 
be due to the stratification of the mountain-snows a view 
which has received later development at the hands of Mr. 
John Ball ; and the practical difficulty of distinguishing 
the undoubted effects of stratification from the phenomena 

* In a letter to myself, published in the 17th volume of the ' Philoso- 
phical Magazine,' Professor Forbes writes as follows : " In 1846, then, I 
abandoned no part of the theory of the veined structure, on which as you 
say so much labour had been expended, except the admission, always 
yielded with reluctance, and got rid of with satisfaction, that the conge- 
lation of water in the crevices of the glacier may extend in winter to a 
great depth." 



USUAL ASPECT OF BLUE VEINS. 



381 



presented by structure, entitles this view to the fullest 
consideration. The blue veins of glaciers are, however, 
not always, nor even generally, such as we should expect 
to result from stratification. The latter would furnish us 
with distinct planes extending parallel to each other for 
considerable distances through the glacier ; but this, 
though sometimes the case, is by no means the general 
character of the structure. We observe blue streaks, from 
a few inches to several feet in length, upon the walls of 
the same crevasse, and varying from the fraction of an 
inch to several inches in thickness. In some cases the 
streaks are definitely bounded, giving rise to an appear- 
ance resembling the section of a lens, and hence called 
the " lenticular structure" by Mr. Huxley and myself ; but 
more usually they fade away in pale washy streaks through 
the general mass of the whitish ice. In Fig. 39 I have 
given a representation of the 
structure as it is very com- 
monly exhibited on the walls 
of crevasses. Its aspect is not 
that which we should expect 
from the consolidation of suc- 
cessive beds of mountain snow. 
Further, at the bases of ice- 
cascades the structural lami- 
nae are usually vertical : below 
the cascade of the Talefre, 
of the Noire, of the Strah- 
leck branch of the Lower 
Grindelwald Glacier, of the 
Rhone, and other ice-falls, 
this is the case ; and it seems extremely difficult to 
conceive that a mass horizontally stratified at the summit 
of the fall, should, in its descent, contrive to turn its strata 
perfectly on end. 




Fig. 39. 



382 ILLUSTRATIVE EXPERIMENTS. 

Again, we often find a very feebly-developed structure 
at the central portions of a glacier, while the lateral por- 
tions are very decidedly laminated. This is the case where 
the inclination of the glacier is nearly uniform through- 
out ; and where no medial moraines occur to complicate 
the phenomenon. But if the veins mark the bedding, 
there seems to be no sufficient reason for their appearance 
at the lateral portions of the glacier, and their absence 
from the centre. 

This leads me to the point at which what I consider 
to be the true cause of the structure may be referred to. 
The theoretic researches of Mr. Hopkins have taught 
us a good deal regarding the pressures and tensions 
consequent upon glacier-motion. Aided by this know- 
ledge, and also by a mode of experiment first introduced 
by Professor Forbes, I will now endeavour to explain the 
significance of the fact referred to in the last paragraph. 
If a plastic substance, such as mud, flow down a sloping 
canal, the lateral portions, being held back by friction, will 
be outstripped by the central ones. When the flow is so 
regulated that the velocity of a point at the centre shall 
not vary throughout the entire length of the canal, a 
coloured circle stamped upon the centre of the mud 
stream, near its origin, will move along with the mud, 
and still retain its circular form ; for, inasmuch as the 
velocity of all points along the centre is the same, there 
can be no elongation of the circle longitudinally or 
transversely by either strain or pressure. A similar ab- 
sence of longitudinal pressure may exist in a glacier, and, 
where it exists throughout, no central structure can, in my 
opinion, be developed. 

But let a circle be stamped upon the mud-stream near 
its side, then, when the mud flows, this circle will be 
distorted to an oval, with its major axis oblique to the 
direction of motion ; the cause of this is that the portion 




MAKGINAL STRUCTURE. 883 

of the circle farthest from the side of the canal moves 
more freely than that adjacent to the side. The mecha- 
nical effect of the slower lateral motion is to squeeze the 
circle in one direction, and. draw it out in the perpendicular 
one. 

A glance at Fig. 40 will render all that I have said in- 
telligible. The three cir- 
cles are first stamped on 
the mud in the same 
transverse line ; but 
after they have moved 
downwards they will be Elg> 40 ' 

in the same straight line no longer. The central one 
will be the foremost ; while the lateral ones have their 
forms changed from circles to ovals. In a glacier of 
the shape of this canal exactly similar effects are pro- 
duced. Now the shorter axis m n of each oval is a 
line of squeezing or pressure ; the longer axis is a line 
of strain or tension ; and the associated glacier-pheno- 
mena are as follows : Across the line m n, or perpen- 
dicular to the pressure, we have the veined structure 
developed, while across the line of tension the glacier 
usually breaks and forms marginal crevasses. Mr. Hopkins 
has shown that the lines of greatest pressure and of greatest 
strain are at right angles to each other, and that in valleys of 
a uniform width they enclose an angle of forty-five degrees 
with the side of the glacier. To the structure thus formed 
I have applied the term marginal structure. Here, then, 
we see that there are mechanical agencies at work near the 
side of such a glacier which are absent from the centre, 
and we have effects developed I believe by the pressure 
in the lateral ice, which are not produced in the central. 

I have used the term " uniform inclination " in con- 
nexion with the marginal structure, and my reason for 
doing so will now appear. In many glaciers the structure, 



384 STEUCTUEE OF GEINDELWALD GLACIEE, 

instead of being confined to the margins, sweeps quite 
across them. This is the case, for example, on the Glacier 
du Geant, the structure of which is prolonged into the 
Mer de Glace. In passing the strait at Trelaporte, how- 
ever, the curves are squeezed and their apices bruised, 
so that the structure is thrown into a state of confusion ; 
and thus upon the Mer de Glace we encounter difficulty 
in tracing it fairly from side to side. Now the key to this 
transverse structure I believe to be the following : Where 
the inclination of the glacier suddenly changes from a 
steep slope to a gentler, as at the bases of the " cas- 
cades," the ice to a certain depth must be thrown into 
a state of violent longitudinal compression; and along 
with this we have the resistance which the gentler slope 
throws athwart the ice descending from the steep one. 
At such places a structure is developed transverse to 
the axis of the glacier, and likewise transverse to the 
pressure. The quicker flow of the centre causes this struc- 
ture to bend more and more, and after a time it sweeps in 
vast curves across the entire glacier. 

In illustration of this point I will refer, in the first place, 
to that tributary of the Lower Glacier of Grindelwald 
which descends from the Strahleck. Walking up this tri- 
butary we come at length to the base of an ice-fall. Let 
the observer here leave the ice, and betake himself to 
either side of the flanking mountain. On attaining a point 
which commands a view both of the fall and of the glacier 
below it, an inspection of the glacier will, I imagine, solve 
to his satisfaction the case of structure now under consi- 
deration. 

It is indeed a grand experiment which Nature here 
submits to our inspection. The glacier descending from 
its neve reaches the summit of the cascade, and is broken 
transversely as it crosses the brow ; it afterwards descends 
the fall in a succession of cliffy ice-ridges with transverse 



BASE OF CASCADE A " STRUCTURE-MILL." 385 

hollows between them. In these latter the broken ice and 
debris collect, thus partially choking the fissures formed in 
the first instance. Carrying the eye downwards along the 
fall, we see, as we approach the base, these sharp ridges 
toned down; and a little below the base they dwindle 
into rounded protuberances which sweep in curves quite 
across the glacier. At the base of the fall the structure 
begins to appear, feebly at first, but becoming gradually 
more pronounced, until, at a short distance below the base 
of the fall, the eye can follow the fine superficial groovings 
from side to side ; while at the same time the ice under- 
neath the surface has become laminated in the most 
beautiful manner. 

It is difficult to convey by writing the force of the evi- 
dence which the actual observation of this natural experi- 
ment places before the mind. The ice at the base of the 
fall, retarded by the gentler inclination of the valley, has 
to bear the thrust of the descending mass, the sudden 
change of inclination producing powerful longitudinal 
compression. The protuberances are squeezed more 
closely together, the hollows between them appear to 
wrinkle up in submission to the pressure in short, the 
entire aspect of the glacier suggests the powerful opera- 
tions of the latter force. At the place where it is exerted 
the veined structure makes its appearance ; and being once 
formed, it moves downwards, and gives a character to other 
portions of the glacier which had no share in its for- 
mation. 

An illustration almost as good, and equally accessi- 
ble, is furnished by the Glacier of the Rhone. I have 
examined the grand cascade of this glacier from both 
, sides; and an ordinary mountaineer will find little diffi- 
culty in reaching a point from which the fall and the 
terminal portion of the glacier are both distinctly visible. 
Here also he will find the cliffy ridges separated from 

C C 



386 



STRUCTURE OF RHONE GLACIER. 



each other by transverse chasms, becoming more and 
more subdued at the bottom of the fall, and disappearing 
entirely lower down the glacier. As in the case of the 
Grindelwald Glacier, the squeezing of the protuberances 
and of the spaces between them is quite apparent, and 
where this squeezing commences the transverse structure 
makes its appearance. All the ice that forms the lower 
portion of this glacier has to pass through the structure- 
mill at the bottom of the fall, and the consequence is that 
it is all laminated. 




Fig. 41. 



This case of structural development will be better appre- 
ciated on reference to Figs. 41 and 42, the former of which 




Fig. 42. 



TRANSVERSE STRUCTURE. 387 

is a plan, and the latter a section, of a part of the 
ice-fall and of the glacier below it ; a b e f is the gorge 
of the fall, / b being the base. The transverse cliffy 
ice-ridges are shown crossing the cascade, being subdued 
at the base to protuberances which gradually disappear as 
they advance downwards. The structure sweeps over the 
glacier in the direction of the fine curved lines ; and I have 
also endeavoured to show the direction of the radial cre- 
vasses, which, in the centre at least,, are at right angles to 
the veins. To the manifestation of structure here consi- 
dered I have, for the sake of convenient reference, applied 
the term transverse structure. 

A third exhibition of the structure is now to be 
noticed. We sometimes find it in the middle of a glacier 
and running parallel to its length. On the centre of the 
ice-fall of the Talefre, for example, we have a structure of 
this kind which preserves itself parallel to the axis of the 
fall from top to bottom. But we discover its origin higher 
up. The structure here has been produced at the extremity 
of the Jardin, where the divided ice meets, and not only 
brings into partial parallelism the veins previously exist- 
ing along the sides of the Jardin, but develops them still 
further by the mutual pressure of the portions of newly 
welded ice. Where two tributary glaciers unite, this is 
perhaps without exception the case. Underneath the 
moraine formed by the junction of the Talefre and Lechaud 
the structure is finely developed, and the veins run in the 
direction of the moraine. The same is true of the ice 
under the moraine formed by the junction of the Lechaud 
and Geant. These afterwards form the great medial mo- 
raines of the Mer de Glace, and hence the structure of the 
trunk-stream underneath these moraines is parallel to the 
direction of the glacier. This is also true of the system of 
moraines formed by the glaciers of Monte Rosa. It is 
true in an especial manner of the lower glacier of the Aar, 

c c 2 



888 



LONGITUDINAL STKUCTUKE. 



whose medial moraine perhaps attains grander proportions 
than any other in the Alps, and underneath which the 
structure is finely developed. 

The manner in which I have illustrated the production 
of this structure will be understood from Fig. 43. B B 

are two wooden boxes, 
communicating by 
sluice-fronts with two 
branch canals, which 
unite to a common 
trunk atG. They are 
intended to. represent 
respectively the trunk 
and tributaries of the 
Unteraar Glacier, the 
part G being the Ab- 
schwung, where the 
Lauteraar and Fin- 
steraar glaciers unite 
to form the Unteraar. 
The mud is first per- 
Fig - 43> mitted to flow beneath 

the two sluices until it has covered the bottom of the 
trough for some distance, when it is arrested. The end of 
a glass tube is then dipped into a mixture of rouge and 
water, and small circles are stamped upon the mud. The 
two branches are thickly covered with these circles. The 
sluices being again raised, the mud in the branches moves 
downwards, carrying with it the circles stamped upon it ; 
and the manner in which these circles are distorted enables 
us to infer the strains and pressures to which the mud is 
subjected during its descent. The figure represents approxi- 
mately what takes place. The side-circles, as might be ex- 
pected, are squeezed to oblique ovals, but it is at the 
junction of the branches that the chief eifect of pressure is 




EFFOETS TO SOLVE QUESTION. 389 

produced. Here, by the mutual thrust of the branches, the 
circles are not only changed to elongated ellipses, but even 
squeezed to straight lines. In the case of the glacier this 
is the region at which the structure receives its main 
development. To this manifestation of the veins I have 
applied the term longitudinal structure. 

The three main sources of the blue veins are, I think, 
here noted ; but besides these there are many local causes 
which influence their production. I have seen them well 
formed where a glacier is opposed by the sudden bend of 
a valley, or by a local promontory which presents an ob- 
stacle sufficient to bring the requisite pressure into play. 
In the glaciers of the Tyrol and of the Oberland I have 
seen examples of this kind ; but the three principal 
sources of the veins are, I think, those stated above. 

It was long before I cleared my mind of doubt regard- 
ing the origin of the lamination. When on the Mer de 
Glace in 1857 I spared neither risk nor labour to instruct 
myself regarding it. I explored the Talefre basin, its cas- 
cade, and the ice beneath it. Several days were spent 
amid the ice humps and cliffs at the lower portion of 
the fall. I suppose I traversed the Glacier du Geant 
twenty times, and passed eight or ten days amid the con- 
fusion of its great cascade. I visited those places where, 
it had been affirmed, the veins were produced. I endea- 
voured to satisfy myself of the mutability which had been 
ascribed to them ; but a close examination reduced the 
value of each particular case so much that I quitted the 
glacier that year with nothing more than an opinion that 
the structure and the stratification were two different 
things. I, however, drew up a statement of the facts 
, observed, with the view of presenting it to the Eoyal 
Society ; but I afterwards felt that in thus acting I should 
merely swell the literature of the subject without adding 
anything certain. I therefore withheld the paper, and 



390 EXPEDITION FOE THIS PURPOSE. 

resolved to devote another year to a search among the chiet 
glaciers of the Oberland, of the Canton Valais, and of Savoy, 
for proofs which should relieve my mind of all doubt upon 
the subject. 

Accordingly in 1858 I visited the glaciers of Rosenlaui, 
Schwartzwald, Grindelwald, the Aar, the Ehone, and the 
Aletsch, to the examination of which latter I devoted more 
than a week. I afterwards went to Zermatt, and, taking up 
my quarters at the Riffelberg, devoted eleven days to the 
examination of the great system of glaciers of Monte Rosa. 
I explored the Gorner Glacier up almost to the Cima de 
Jazzi ; and believed that in it I could trace the structure 
from portions of the glacier where it vanished, through 
various stages of perfection, up to its full development. I 
believe this still ; but yet it is nothing but a belief, which 
the utmost labour that I could bestow did not raise 
to a certainty. The Western glacier of Monte Rosa, the 
Schwartze Glacier, the Trifti Glacier, the glacier of the 
little Mont Cervin, and of St. Theodule, were all examined 
in connexion with the great trunk-stream of the Gorner, 
to which they weld themselves ; and though the more I 
pursued the subject the stronger my conviction became 
that pressure was the cause of the structure, a crucial case 
was still wanting. 

In the phenomena of slaty cleavage, it is often, if not 
usually, found that the true cleavage cuts the planes of 
stratification sometimes at a very high angle. Had this 
not been proved by the observations of Sedgwick and 
others, geologists would not have been able to conclude that 
cleavage and bedding were two different things, and 
needed wholly different explanations. My aim, throughout 
the expedition of 1858, was to discover in the ice a parallel 
case to the above ; to find a clear and undoubted instance 
where the veins and the stratification were simultaneously 
exhibited, cutting each other at an unmistakable angle. 



CASE OF STKUCTUEE ON THE ALETSCH. 391 

On the 6th of August, while engaged with Professor 
Kamsay upon the Great Aletsch Glacier, not far from 
its junction with the Middle Aletsch , I observed what 
appeared to me to be the lines of bedding running nearly 
horizontal along the wall of a great crevasse, while cut- 
ting them at a large angle was the true veined structure. 
I drew my friend's attention to the fact, and to him it 
appeared perfectly conclusive. It is from a sketch made 
by him at the place that Fig. 44 has been taken. 




Fig. 44. 

This was the only case of the kind which I observed 
upon the Aletsch Glacier ; and as I afterwards spent day 
after day upon the Monte Kosa glaciers, vainly seek- 
ing a similar instance, the thought again haunted me 
that we might have been mistaken upon the Aletsch. 
In this state of mind I remained until the 18th of August, 
a day devoted to the examination of the Furgge Glacier, 
which lies at the base of the Mont Cervin. 

Crossing the valley of the Gorner Glacier, and taking a 
plunge as I passed into the Schwarze See, I reached, in 
good time, the object of my day's excursion. Walking up 
the glacier, I at length found myself opposed by a frozen 
cascade composed of four high terraces of ice. The 
highest of these was chiefly composed of ice-cliffs and 
j many of which had fallen, and now stood like 



392 STKUCTUKE OF THE FURGGE GLACIER. 

rocking-stones upon the edge of the second terrace. The 
glacier at the base of the cascade was strewn with 
broken ice, and some blocks two hundred cubic feet in 
volume had been cast to a considerable distance down 
the glacier. 

Upon the faces of the terraces the stratification of the 
neve was most beautifully shown, running in parallel and 
horizontal lines along the weathered surface. The snow- 
field above the cascade is a frozen plain, smooth almost as 
a sheltered lake. The successive snow-falls deposit them- 
selves with great regularity, and at the summit of the 
cascade the sections of the neve are for the first time 
exposed. Hence their peculiar beauty and definition. 

Indeed the figure of a lake pouring itself over a rocky 
barrier which curves convexly upwards, thus causing the 
water to fall down it, not only longitudinally over the 
vertex of the curve, but laterally over its two arms, will 
convey a tolerably correct conception of the shape of the 
fall. Towards the centre the ice was powerfully squeezed 
laterally, the beds were bent, and their continuity often 
broken by faults. On inspecting the ice from a distance 
with my opera glass, I thought I saw structural groovings 
cutting the strata at almost a right angle. Had the ques- 
tion been an undisputed one, I should perhaps have felt 
so sure of this as not to incur the danger of pushing the 
inquiry further; but, under the circumstances, danger 
was a secondary point. Eesigning, therefore, my glass 
to my guide, who was to watch the tottering blocks over- 
head, and give me warning should they move, I advanced 
to the base of the fall, removed with my hatchet the 
weathered surface of the ice, and found underneath it the 
true veined structure, cutting, at nearly a right angle, the 
planes of stratification. The superficial groovings were not 
uniformly distributed over the fall, but appeared most 
decided at those places where the ice appeared to have 



ICE TERRACE EXAMINED. 393 

been most squeezed. I examined three or four of these 
places, and in each case found the true veins nearly ver- 
tical, while the bedding was horizontal. Having perfectly 
satisfied myself of these facts, I made a speedy retreat, 
for the ice-blocks seemed most threatening, and the sunny 
hour was that at which they fall most frequently. 

I next tried the ascent of the glacier up a dislocated 
declivity to the right. The ice was much riven, but 
still practicable. My way for a time lay amid fissures 
which exposed magnificent sections, and every step I 
took added further demonstration to what I had observed 
below. The strata were perfectly distinct, the structure 
equally so, and one crossed the other at an angle 01 
seventy or eighty degrees. Mr. Sorby has adduced a case 
of the crumpling of a bed of sandstone through which 
the cleavage passes : here on the glacier I had parallel 
cases ; the beds were bent and crumpled, but the struc- 
ture ran through the ice in sharp straight lines. This 
perhaps was the most pleasant day I ever spent upon 
the glaciers : my mind was relieved of a long brooding 
doubt, and the intellectual freedom thus obtained added 
a subjective grandeur to the noble scene before me. 
Climbing the cliffs near the base of the Matterhorn, I 
walked along the rocky spine which extends to the Hornli, 
and afterwards descended by the valley of Zmutt to Zer- 
matt. 

A year after my return to England a remark contained 
in Professor Mousson's interesting little work 'Die Gletscher 
der Jetzzeit ' caused me to refer to the atlas of M. 
Agassiz's c Systeme Glaciaire,' from which I learned that 
this indefatigable observer had figured a case of stratifi- 
cation and structure cutting each other. If, however, I 
had seen this figure beforehand, it would not have changed 
my movements ; for the case, as sketched, would not have 
convinced me. I have now no doubt that M. Agassiz has 



394 



LAMINATION AND STRATIFICATION. 






preceded me in this observation, and hence my results are 

to be taken as mere confirmations of his. 

Fig. 45 represents a 
crumpled portion of the ice 
with the lines of lamination 
passing through the strata. 
Fig. 46 represents a case 
where a fault had oc- 
curred, the veins at both 

sides of the line of dislocation being inclined towards each 

other. 





[Figs. 45 and 46 are from sketches made on the Furgge Glacier. L. C. T.] 






DIFFERENTIAL MOTION GREATEST AT EDGES. 395 



THE VEINED STRUCTURE AND THE 
DIFFERENTIAL MOTION. 

(28.) 

I HAVE now to examine briefly the explanation of the 
structure which refers it to differential motion to a sliding 
of the particles of ice past each other, which leaves the 
traces of its existence in the blue veins. The fact is em- 
phatically dwelt upon by those who hold this view, that 
the structure is best developed nearest to the sides of the 
glacier, where the differential motion is greatest. Why 
the differential motion is at its maximum near to the 
sides is easily understood. Let A B, A ... c< 
c D, Fig. 47, represent the two sides 
of a glacier, moving in the direction of 
the arrow, and let m a b c n be a 
straight line of stakes set out across 
the glacier to-day. Six months hence 
this line, by the motion of the ice 
downwards, will be bent to the form 
m a' I' c' n: this curve will not be cir- 
cular, it will be flattened in the middle ; 
the points a and c, at some distance 
on each side of the centre 6, move in rig. 47. 

fact with nearly the same velocity as the centre itself. 
Not so with the sides : a' and c' have moved considerably 
in advance of m and n, and hence we say that the differ- 
ence of motion, or the differential motion, of the particles 
of ice near to the side is a maximum. 

During all this time the points m a' V c r n have been 
moving straight down the glacier ; and hence it will be 
understood that the sliding of the parts past each other, 



396 STKUCTUEE OBLIQUE TO SIDES. 

or in other words, the differential motion, is parallel to the 
sides of the glacier. This, indeed, is the only differential 
motion that experiment has ever established ; and conse- 
quently, when we find the best blue veins referred to 
the sides of the glacier because the differential motion 
is there greatest, we naturally infer that the motion meant 
is parallel to the sides. 

But the fact is, that this motion would not at all account 
for the blue veins, for they are not parallel to the sides, 
but oblique to them. This difficulty revealed itself after a 
time to those who first propounded the theory of differen- 
tial motion, and caused them to modify their explanation 
of the structure. Differential motion is still assumed to be 
the cause of the veins, but now a motion is meant oblique to 
the sides, and it is supposed to be obtained in the following 
way : Through the quicker motion of the point c' the 
ice between it and n becomes distended ; that is to 
say, the line c' n is in a state of strain there is a drag, 
it is said, oblique to the sides of the glacier ; and it 
is therefore in this direction that the particles will be 
caused to slide past each other. Dr. Whew ell, who ad- 
vocates this view, thus expounds it. He supposes the case 
of an alpine valley filled with india-rubber which has been 
warmed until it has partially melted, or become viscous, and 
then asks, " What will now be the condition of the mass ? 
The sides and bottom will still be held back by the fric- 
tion ; the middle and upper part will slide forwards, but not 
freely. This want of freedom in the motion (arising from 
the viscosity) will produce a drag towards the middle of 
the valley, where the motion is freest; hence the direction 
in which the filaments slide past each other will be ob- 
liquely directed towards the middle. The sliding will 
separate the mass according to such lines ; and though new 
attachments will take place, the mass may be expected to 
retain the results of this separation in the traces of parallel 



STRUCTURE CROSSES LINES OF SLIDING 397 

fissures." * Nothing can be clearer than the image of the 
process thus placed before the mind's eye. 

One fact of especial importance is to be borne in mind : the 
sliding of filaments which is thus supposed to take place 
oblique to the glacier has never been proved ; it is wholly 
assumed. A moraine, it is admitted, will run parallel to 
the side of a glacier, or a block will move in the same 
direction from beginning to end, without being sensibly 
drawn towards the centre, but still it is supposed that the 
sliding of parts exists, though of a character so small as 
to render it insensible to measurement. 

My chief difficulty as regards this theory may be ex- 
pressed in a very few words. If the structure be produced 
by differential motion, why is the large and real differential 
motion which experiments have established incompetent 
to produce it ? And how can the veins run, as they are 
admitted to do, across the lines of maximum sliding from 
their origin throughout the glacier to its end ? 

That a drag towards the centre of the glacier exists is 
undeniable, but that in consequence of the drag there is a 
sliding of filaments in this direction, is quite another thing. 
I have in another place f endeavoured to show experi- 
mentally that no such sliding takes place, that the drag 
on any point towards the centre expresses only half the 
conditions of the problem ; being exactly neutralized by 
the thrust towards the sides. It has been, moreover, 
shown by Mr. Hopkins that the lines of maximum strain 
and of maximum sliding cannot coincide ; indeed, if all the 
particles be urged by the same force, no matter how 
strong the pull may be, there will be no tendency of one 
to slide past the other. 

* 'Philosophical Magazine,' Ser. III., vol. xxvi. 

t ' Proceedings of the Royal Institution,' vol. ii. p. 324. 



398 THEORY STATED. 

THE RIPPLE-THEORY OF THE VEINED 
STRUCTURE. 

(29.) '' . 

THE assamption of oblique sliding, and the production 
thereby of the marginal structure, have, however, been 
fortified by considerations of an ingenious and very inte- 
resting kind. " How," I have asked, " can the oblique 
structure persist across the lines of greatest differential 
motion throughout the length of the glacier ? " But here I 
am met by another question which at first sight might 
seem equally unanswerable " How do ripple-marks on 
the surface of a flowing river, which are nothing else 
than lines of differential motion of a low order, cross the 
river from the sides obliquely, while the direction of greatest 
differential motion is parallel to the sides ? " If I under- 
stand aright, this is the main argument of Professor Forbes 
in favour of his theory of the oblique marginal structure. 
It is first introduced in a note at page 378 of his c Travels ; ' 
he alludes to it in a letter written the following year ; in his 
paper in the ' Philosophical Transactions ' he develops the 
theory. He there gives drawings of ripple-marks observed 
in smooth gutters after rain, arid which he finds to be in- 
clined to the course of the stream, exactly as the marginal 
structure is inclined to the side of the glacier. The explana- 
tion also embraces the case of an obstacle placed in the centre 
of a river. " A case," writes Professor Forbes, " parallel 
to the last mentioned, where a fixed obstacle cleaves a de- 
scending stream, and leaves its trace in a fan-shaped tail, 
is well known in several glaciers, as in that at Ferpecle, 
and the Glacier de Lys on the south side of Monte Rosa ; 
particularly the last, where the veined structure follows 
the law just mentioned." In his Twelfth Letter he 



THEORY EXAMINED. 399 

also refers to the ripples " as exactly corresponding to 
the position of the icy bands." In his letter to Dr. 
Whewell, published in the ' Occasional Papers,' page 58, 
he writes as follows : " The same is remarkably shown 
in the case of a stream of water, for instance a mill- 
race. Although the movement of the water, as shown 
by floating bodies, is exceedingly nearly (for small velo- 
cities sensibly) parallel to the sides, yet the variation 
of the speed from the side to the centre of the stream 
occasions a ripple, or molecular discontinuity, which 
inclines forwards from the sides to the centre of the 
stream at an angle with the axis depending on the 
ratio of the central and lateral velocity. The veined 
structure of the ice corresponds to the ripple of the water, 
a molecular discontinuit} T whose measure is not com- 
parable to the actual velocity of the ice ; and therefore 
the general movement of the glacier, as indicated by the 
moraines, remains sensibly parallel to the sides." This 
theory opens up to us a series of interesting and novel 
considerations which I think will repay the reader's atten- 
tion. If the ripples in the water and the veins in the 
ice be due to the same mechanical cause, when we develop 
clearly the origin of the former we are led directly to the 
explanation of the latter. I shall now endeavour to re- 
duce the ripples to their mechanical elements. 

The Messrs. Weber have described in their ' Wellen- 
lehre ' an effect of wave- mot ion which it is very 
easy to obtain. When a boat moves through perfectly 
smooth water, and the rower raises his oar out of the 
water, drops trickle from its blade, and each drop where it 
falls produces a system of concentric rings. The cir- 
cular waves as they widen become depressed, and, it 
the drops succeed each other with sufficient speed, the 
rings cross each other at innumerable points. The effect 
of this is to blot out more or less completely all the 



400 RIPPLES DEDUCED FROM RINGS. 

circles, and to leave behind two straight divergent 
ripple-lines, which are tangents to all the external rings ; 
being in fact formed by the intersections of the latter, 
as a caustic in optics is formed by the intersection of 
luminous rays. Fig. 48, which is virtually copied from 




Fig. 48. 



M. Weber, will render this description at once intelli- 
gible. The boat is supposed to move in 1^ie direction ot 
the arrow, and as it does so the rings hich it leaves 
behind widen, and produce the diverge*" e of the two 
straight resultant lines of ripple. 

The more quickly the drops succeed each other, the 
more frequent will be the intersections of the rings ; but as 
the speed of succession augments we apr -oach the case 
of a continuous vein of liquid ; and if we sr ose the con- 
tinuity to be perfectly established, the ripp will still be 
produced with a smooth space between f n as before. 
This experiment may indeed be made witt i well-wetted 
oar, which on its first emergence from the water sends into 
it a continuous liquid vein. The same effect is produced 
when we substitute for the stream of liquid a solid rod 
a common walking-stick for example. A water-fowl swim- 
ming in calm, water produces two divergent lines of ripples 
of a similar kind. 

We have here supposed the water of the lake to be at 
rest, and the liquid vein or the solid rod to uove through 



MEASUKE OF DIVEKGENCE OF KIPPLES. 401 

it ; but precisely the same effect is produced if we suppose 
the rod at rest and the liquid in motion. Let a post, for 
example, be fixed in the middle of a flowing river ; diverg- 
ing from that post right and left we shall have lines of 
ripples exactly as if the liquid were at rest and the post 
moved through it with the velocity of the river. If the 
same post be placed close to the bank, so that one of its 
edges only shall act upon the water, diverging from that 
edge we shall have a single line of ripples which will cross 
the river obliquely towards its centre. It is manifest that 
any other obstac u - will produce the same effect as our 
hypothetical post. In the words of Professor Forbes, " the 
slightest prominence of any kind in the wall of such a 
conduit, a bit oFj wood or a tuft of grass, is sufficient to 
produce a well-marked ripple-streak from the side towards 
the centre." 

The foregoing considerations show that the divergence 
of the two liner, of ripple^ from the central post, and of 
the single line ^n the case of the lateral post, have their 
mechanical elei vent, if I may use the term, in the 
experiment of ,ae Messrs. Weber. In the case of a 
swimming duck the connexion between the diverging 
lines of ripples and the propagation of rings round a 
disturbed poir; &, often very prettily shown. When the 
creature swir ,- ,vith vigour the little foot with which 
it strikes the later often comes sufficiently near to the 
surface to proc ve an elevation. sometimes indeed emerg- 
ing from the w^ier altogether. Kouiid the point thus dis- 
turbed rings are immediately propagated, and the widening 
of those rings is the exact measure of the divergence of the 
ripple lines. The rings never cross the lines ; the lines 
never retreat from the rings. 

If we compare the mechanical actions here traced out 
with those which take place upon a glacier, I think it will 
be seen that the analogy between the ripples and the 

D D 



402 KIPPLES AND VEINS DUE TO DIFFEKENT CAUSES. 

veined structure is entirely superficial. How the struc- 
ture ascribed to the Glacier de Lys is to be explained I 
do not know, for I have never seen it ; but it seems im- 
possible that it could be produced, as ripples are, by a fixed 
obstacle which "cleaves a descending stream." No one 
surely will affirm that glacier-ice so closely resembles a 
fluid as to be capable of transmitting undulations, as water 
propagates rings round a disturbed point. The difficulty 
of such a supposition would be augmented by taking into 
account the motion of the individual liquid particles which 
go to form a ripple ; for the Messrs. Weber have shown 
that these move in closed curves, describing orbits more 
or less circular. Can it be supposed that the particles of 
ice execute a motion of this kind? If do, their orbital 
motions may be easily calculated, being deducible from 
the "motion of the glacier compounded with the inclination 
of the veins. If so important a result could be established, 
all glacier theories would vanish Ji^ comparison with it. 

There is another interesting point involved in the pas- 
sage above quoted. Professor Forbes considers that the 
ripple is occasioned by the variation of speed from the side 
to the centre of the stream, and that its inclination depends 
on the ratio of the central and lateral velocity. If I am 
correct in the above analysis, this cannot be the case. The 
inclination of the ripple depends solely on the ratio of the 
river's translatory motion to the velocity of its wave- 
motion. Were the lateral and central velocities alike, a 
momentary disturbance it the side would produce a straight 
ripple-mark, whose inclination would be compounded of 
the two elements just mentioned. If the motion of the 
water vary from side to centre, the velocity of wave-pro- 
pagation remaining constant, the inclination of the ripple 
will also vary, that is to say, we shall have a curved ripple 
instead of a straight one. This, of course, is the case which 
we find in Nature, but the curvature of such ripples is 



POSITION OF RIPPLES NOT THAT OF STRUCTURE. 403 

totally different from that of the veined structure. Owing 
to the quicker translatory movement, the ripples, as they 
approach the centre, tend more to parallelism with the 
direction of the river ; and after having passed the centre, 
and reached the slower water near the opposite side, their 
inclination to the axis gradually augments. Thus the 
ripples from the two sides form a pair of symmetric curves, 
which cross each other at the centre, and possess the form 
a o b, c o dj shown in Fig. 49. A similar pair of curves 




Fig. 49. 



would be produced by the reflection of these. Knowing 
the variation of motion from side to centre, any competent 
mathematician could find the equation of the ripple-curves ; 
but it would be out of place for me to attempt it here. 



404 POSSIBLE EXPERIMENT WITH GLASS PRISM. 

THE VEINED STRUCTURE AND PRESSURE. 

(30.) - 

IF a prism of glass be pressed by a sufficient weight, the 
particles in the line of pressure will be squeezed more 
closely together, while those at right angles to this line 
will be forced further apart. The existence of this state of 
strain may be demonstrated by the action of such squeezed 
glass upon polarised light. It gives rise to colours, and 
it is even possible to infer from the tint the precise amount 
of pressure to which the glass is subjected. M. Wert- 
heim indeed has most ably applied these facts to the 
construction of a dynamometer, or instrument for measuring 
pressures, exceeding in accuracy any hitherto devised. 

When the pressure applied becomes too great for the 
glass to sustain, it flies to pieces. But let us suppose the 
sides of the prism defended by an extremely strong jacket, 
in which the prism rests like a closely-fitting plug, and 
which yields only when a pressure more than sufficient to 
crush the glass is applied. Let the pressure be gradually 
augmented until this point is attained ; afterwards both the 
glass and its jacket will shorten and widen ; the jacket will 
yield laterally, being pushed out with extreme slowness by 
the glass within. 

Now I believe that it would be possible to make this 
experiment in such a manner that the glass should be 
flattened, partly through rupture, and partly through lateral 
molecular yielding ; the prism would change its form, and 
yet present a firmly coherent mass when removed from its 
jacket. I have never made the experiment ; nobody has, 
as far as I know ; but experiments of this kind are often 
made by Nature. In the Museum of the Government 



POSSIBLE EXPERIMENT WITH PRISM OF ICE. 405 

School of Mines, for example, we have a collection of 
quartz stones placed there by Mr. Salter, and which have 
been subjected to enormous pressure in the neighbourhood 
of a fault. These rigid pebbles have, in some cases, been 
squeezed against each other so as to produce mutual flat- 
tening and indentation. Some of them have yielded along 
planes passing through them, as if one half had slidden over 
the other ; but the reattachment is very strong. Some of 
the larger stones, moreover, which have endured pressure 
at a particular point, are fissured radially around this 
point. In short, the whole collection is a most instructive 
example of the manner and extent to which one of the 
most rigid substances in Nature can yield on the applica- 
tion of a sufficient force. 

Let a prism of ice at 32 be placed in a similar jacket 
to that which we have supposed to envelop the glass prism. 
The ice yields to the pressure with incomparably greater 
ease than the glass ; and if the force be slowly applied, the 
lateral yielding will far more closely resemble that of a 
truly plastic body. Supposing such a piece of ice to be 
filled with numerous small air-bubbles, the tendency of the 
pressure would be to flatten these bubbles, and to squeeze 
them out of the ice. Were the substance perfectly homo- 
geneous, this flattening and expulsion would take place 
uniformly throughout its entire mass ; but I believe there 
is no such homogeneous substance in nature ; the ice will 
yield at different places, leaving between them spaces 
which are comparatively unaffected by the pressure. From 
the former spaces the air-bubbles will be more effectually 
expelled; and I have no doubt that the result of such 
pressure acting upon ice so protected would be to pro- 
duce a laminated structure somewhat similar to that which 
it produces in those bodies which exhibit slaty cleavage. 

I also think it certain that, in this lateral displace- 
ment of the particles, these must move past each other. 



406 LAMINATION PRODUCED BY PRESSURE. 

This is an idea which I have long entertained, as the 
following passage taken from the paper published by 
Mr. Huxley and myself will prove :" Three principal 
causes may operate in producing cleavage: first, the 
reducing of surfaces of weak cohesion to parallel planes ; 
second, the flattening of minute cavities; and third, 
the weakening of cohesion by tangential action. The 
third action is exemplified by the state of the rails near 
a station where a break is habitually applied to a loco- 
motive. In this case, while the weight of the train presses 
vertically, its motion tends to cause longitudinal sliding of 
the particles of the rail. Tangential action does not, how- 
ever, necessarily imply a force of the latter kind. When 
a solid cylinder an inch in height is squeezed to a vertical 
cake a quarter of an inch in height, it is impossible, phy- 
sically speaking, that the particles situated in the same 
vertical line shall move laterally with the same velocity ; 
but if they do not, the cohesion between them will be 
weakened or ruptured. The pressure, however, will pro- 
duce new contact ; and if this have a cohesive value equal 
to that of the old contact, no cleavage from this cause can 
arise. The relative capacities of different substances for 
cleavage appear to depend in a great measure upon their 
different properties in this respect. In butter, for ex- 
ample, the new attachments are equal, or nearly so, to the 
old, and the cleavage is consequently indistinct ; in wax 
this does not appear to be the case, and hence may arise 
in a great degree the perfection of its cleavage. The 
further examination of this subject promises interesting 
results." I would dwell upon this point the more distinctly 
as the advocates of differential motion may deem it to be 
in their favour ; but it appears to me that the mechanical 
conceptions implied in the above passage are totally 
different from theirs. If they think otherwise, then it 
seems to me that they should change the expressions which 



NO SLIDING OF FILAMENTS. 407 

refer the differential motion to a "drag" towards the 
centre, and the structure to the sliding of " filaments " past 
each other in consequence of this drag. Such filamentary 
sliding may take place in a truly viscous body, but it does 
not take place in ice. 

In one particular the ice resembles the butter referred 
to in the above quotation ; for its new attachments appear 
to be equal to the old, and this, I think, is to be ascribed 
to its perfect regelation. As justly pointed out by Mr. 
John Ball, the veined ice of a glacier, if unweathered, 
shows no tendency to cleave; for though the expul- 
sion of the air-bubbles has taken place, the reattach- 
ment of the particles is so firm as to abolish all evidence 
of cleavage. When the ice, on the contrary, is weathered, 
the plates become detached, and I have often been able to 
split such ice into thin tablets having an area of two or 
three square feet. 

In his Thirteenth Letter Professor Forbes throws out a 
new and possibly a pregnant thought in connexion with the 
veins. If I understand him aright and I confess it is 
usually a matter of extreme difficulty with me to make 
sure of this he there refers the veins, not to the expulsion 
of the air from the ice, but to its redistribution. The pres- 
sure produces " lines of tearing in which the air is distri- 
buted in the form of regular globules." I do not know 
what might be made of this idea if it were developed, but 
at present I do not see how the supposed action could 
produce the blue bands ; and I agree with Professor Wm. 
Thomson in regarding the explanation as improbable.* 

* For an extremely ingenious view of the origin of the veined struc- 
ture, I would refer to a paper by Professor Thomson, in the ' Proceedings 
of the Eoyal Society,' April, 1858. 



408 INFLUENCE OF PRESSURE ON BOILING POINT. 

THE VEINED STRUCTURE AND THE LIQUEFAC- 
TION OF ICE BY PRESSURE. 

(31.) 

I HAVE already noticed an important fact for which we 
are indebted to Mr. James Thomson, and have referred to 
the original communications on the subject. I shall here 
place the physical circumstances connected with this fact 
before my reader in the manner which I deem most likely 
to interest him. 

When a liquid is heated, the attraction of the molecules 
operates against the action of the heat, which tends to tear 
them asunder. At a certain point the force of heat 
triumphs, the cohesion is overcome, and the liquid boils. 
But supposing we assist the attraction of the molecules by 
applying an external pressure, the difficulty of tearing 
them asunder will be increased ; more heat will be re- 
quired for this purpose ; and hence we say that the boiling 
point of the liquid, has been elevated by the pressure. 

If molten sulphur be poured into a bullet-mould, it will 
be found on cooling to contract, so as to leave a large 
hollow space in the middle of each sphere. Cast musket- 
bullets are thus always found to possess a small cavity 
within them produced by the contraction of the lead. 
Conceive the bullet placed within its mould and the 
latter heated ; to produce fusion it is necessary that the 
sulphur or the lead should swell. Here, as in the case of 
the heated water, the tendency to expand is opposed by the 
attraction of the molecules ; with a certain amount of heat 
however this attraction is overcome and the solid melts. 
But suppose we assist the molecular attraction by a suitable 
force applied externally, a greater amount of heat than 
before will be necessary to tear them asunder ; and hence 



INFLUENCE OF PEESSUEE ON FUSING POINT. 409 

we say that the fusing point has been elevated by the pres- 
sure. This fact has been experimentally established by 
Messrs. Hopkins and Fairbairn, who applied to spermaceti 
and other substances pressures so great as to raise their 
points of fusion a considerable number of degrees. 

Let us now consider the case of the metal bismuth. If 
the molten metal be poured into a bullet-mould it will 
expand on solidifying. I have myself filled a strong cast- 
iron bottle with the metal, and found its expansion on 
cooling sufficiently great to split the bottle from neck to 
bottom. Hence, in order to fuse the bismuth the substance 
must contract ; and it is manifest that an external pressure 
which tends to squeeze the molecules more closely together 
here assists the heat instead of opposing it. Hence, to 
fuse bismuth under great pressure, a less amount of 
heat will be required than when the pressure is removed ; 
or, in other words, the fusing point of bismuth is lowered 
by the pressure. Now, in passing from the solid to the 
liquid state, ice, like bismuth, contracts, and if the con- 
traction be promoted by external pressure, as shown by 
the Messrs. Thomson, a less amount of heat suffices to 
liquefy it. 

These remarks will enable us to understand a singular 
effect first obtained by myself at the close of 1856 or in 
January 1857, noticed at the time in the ' Proceedings of 
the Koyal Society,' and afterwards fully described in a 
paper presented to the Society in December of that year. 
A cylinder of clear ice two inches high and an inch in 
diameter was placed between two slabs of box- wood, and 
subjected to a gradual pressure. I watched the ice in a 
direction perpendicular to its length, and saw cloudy lines 
drawing themselves across it. As the pressure continued, 
these lines augmented in numbers, until finally the prism 
presented the appearance of a crystal of gypsum whose 
planes of cleavage had been forced out of optical contact. 



410 



EXPERIMENTS. 





When looked at obliquely it was found that the lines were 
merely the sections of flat dim surfaces, which lay like 

laminae one over the other 
throughout the length of 
the prism. Fig. 50 repre- 
sents the prism as it ap- 
peared when looked at in a 
direction perpendicular to 
its axis ; Fig. 51 shows the 
appearance when viewed 
Fig. so. Fig. 51. obliquely.* 

At first sight it might appear as if air had intruded itself 
between the separated surfaces of the ice, and to test this 
point I placed a cylinder two inches long and an inch wide 
upright in a copper vessel which was filled with ice-cold 
water. The ice cylinder rose about half an inch above the 
surface of the water. Placing the copper vessel on a slab 
of wood, and a second slab on the top of the cylinder of 
ice, the latter was subjected to the gradual action of a 
small hydraulic press. When the hazy surfaces were well 
developed in the portion of the ice above the water, the 
cylinder was removed and examined : the planes of rupture 
extended throughout the entire length of the cylinder, 
just as if it had been squeezed in air. I subsequently 
placed the ice in a stout vessel of glass, and squeezed it, 
as in the last experiment : the surfaces of discontinuity 
were seen forming under the liquid quite as distinctly as 
in air. 

To prove that the surfaces were due to compression and 
not to any tearing asunder of the mass by tension, the fol- 
lowing experiment was made : A cylindrical piece of ice, 
one of whose ends, however, was not parallel to the other, 
was placed between the slabs of wood, and subjected to 

* This effect projected upon a screen is a most striking and instructive 
class experiment. 



LIQUID LAYERS PRODUCED BY PRESSURE. 411 

pressure. Fig. 52 shows the disposition of the experiment. 
The effect upon the ice cylinder was that shown in 




Fig. 52. 



Fig. 53. 



Fig. 53, the surfaces being developed along that side which 
had suffered the pressure. On examining the surfaces by 
a pocket lens they resembled the effect produced upon a 
smooth cold surface by breathing on it. 

The surfaces were always dim ; and had the spaces been 
filled with air, or were they simply vacuous, the reflection 
of light from them would have been so copious as to render 
them much more brilliant than they were observed to be. To 
examine them more particularly I placed a concave mirror 
so as to throw the diffused daylight from a window full 
upon the cylinder. On applying the pressure dim spots 
were sometimes seen forming in the very middle of the 
ice, and these as they expanded laterally appeared to be 
in a state of intense motion, which followed closely the 
edge of each surface as it advanced through the solid ice. 
Once or twice I observed the hazy surfaces pioneered 
through the mass by dim offshoots, apparently liquid, and 
constituting a kind of decry stallisation. From the closest 
examination to which I was able to subject them, the 
surfaces appeared to me to be due to internal lique- 
faction ; indeed, when the melting point of ice, having 
already a temperature of 32, is lowered by pressure, its 
excess of heat must instantly be applied to produce this 
effect. 

I have already given a drawing (p. 386) showing the deve- 



412 APPLICATION TO THE VEINED STRUCTURE. 

lopment of the veined structure at the base of the ice-cascade 
of the Rhone ; and if we compare that diagram with Fig. 
53 a striking similarity at once reveals itself. The ice of 
the glacier must undoubtedly be liquefied to some extent 
by the tremendous pressure to which it is here subjected. 
Surfaces of discontinuity will in all probability be formed, 
which facilitate the escape of the imprisoned air. The 
small quantity of water produced will be partly im- 
bibed by the adjacent porous ice, and will be refrozen 
when relieved from the pressure. This action, associated 
with that ascribed to pressure in the last section, appears 
to me to furnish a complete physical explanation of the 
laminated structure of glacier-ice. 



GENERAL APPEARANCE OF WHITE ICE-SEAMS. 413 

WHITE ICE-SEAMS IN THE GLACIER 
DU GEANT. 

(32.) 

ON the 28th of July, 1857, while engaged upon the Glacier 
du Geant, iny attention was often attracted by protuberant 
ridges of what at first appeared to be pure white snow, 
but which on examination I found to be compact ice filled 
with innumerable round air-cells ; and which, in virtue of 
its greater power of resistance to wasting, often rose to a 
height of three or four feet above the general level of the ice- 
As I stood amongst these ridges, they appeared detached 
and without order of arrangement, but looked at from a 
distance they were seen to sweep across the proper Glacier 
du Geant in a direction concentric with its dirt-bands and 
its veined structure. In some cases the seams were ad- 
mirable indications of the relative displacement of two 
adjacent portions of the glacier, which were divided from 
each other by a crevasse. Usually the sections of a 
seam exposed on the opposite sides of a fissure accurately 
faced each other, and the direction of the seam on both 
sides was continuous ; but at other places they demon- 
strated the existence of lateral faults, being shifted asunder 
laterally through spaces varying from a few inches to six 
or seven feet. 

On the following day I was again upon the same glacier, 
and noticed in many cases the white ice-seams exquisitely 
honeycombed. The case was illustrative of the great 
difference between the absorptive power of the ice itself 
and of the objects which lie upon its surface. Deep cylin- 
drical cells were produced by spots of black dirt which had 
been scattered upon the surface of the white ice, and 
which sank to a depth of several inches into the mass. I 
examined several sections of the veins, and in general I 



414 



SECTIONS OF SEAMS. 



found that their deeper portions blended gradually with the 
ice on either side of them. But higher up the glacier I 
found that the veins penetrated only to a limited depth, and 
did not therefore form an integrant portion of the glacier. 




Fig. 54. 



Fig. 55. 



Figs. 54 and 55 show the sections of two of the seams 
which were exposed on the wall of a crevasse at some 
distance below the great ice-fall of the Glacier du Geant. 

It was at the base of the Talefre cascade that the expla- 
nation of these curious seams presented itself to me. In 
one of my earliest visits to this portion of the glacier I 

was struck by a singular dispo- 
sition of the blue veins on the 
vertical wall of a crevasse. Fig. 
56 will illustrate what I saw. 
The veins, within a short dis- 
tance, dipped backward and. forward, like the junctions 01 




Fig. 56. 




VARIATIONS IN "DIP" OF STRUCTURE. 415 

stones used to turn an arch. In some cases I found this 
variation of the structure so great as to pass in a short 
distance from the vertical to 
the horizontal, as shown in 
Fig. 57. 

Further examination taught 
me that the glacier here is 
crumpled in a most singular 
manner; doubtless by the 
great pressure to which it ' Fig 

is exposed. The following 

illustration will convey a notion of its aspect: Let one 
hand be laid flat upon a table, palm downwards, and let 
the fingers be bent until the space between the first joint 
and the ends of the fingers is vertical ; one of the crumples 
to which I refer will then be represented. The ice seems 
bent like the fingers, and the crumples of the glacier are 
cut by crevasses, which are accurately typified by the 
spaces between the fingers. Let the second hand now be 
placed upon the first, as the latter is upon the table, so 
that the tops of the bent fingers of the second hand shall 
rest upon the roots of the first : two crumples would thus 
be formed ; a series of such protuberances, with steep 
fronts, follow each other from the base of the Talfre cas- 
cade for some distance downwards. 

On Saturday the 1st of August I ascended these rounded 
terraces in succession, and observed among them an ex- 
tremely remarkable disposition of the structure. Fig. 58 
is a section of a series of three of the crumples, on which 
the shading lines represent the direction of the blue veins. 
At the base of each protuberance I found a seam of white 
ice wedged firmly into the glacier, and each of the seams 
marked a place of dislocation of the veins. The white seams 
thinned off gradually, and finally vanished where the 
violent crumpling of the ice disappeared. In Fig. 59 I 



416 



CRUMPLES OF THE TALEFEE. 



have sketched the wall of a crevs. 
what may be regarded as the incipie 



which represents 
Crumpling. The 




Fig. 58. 



undulating line shows the contour of the surface, and the 
shading lines the veins. It will be observed that the 
direction of the veins yields in conformity wit i the undu- 
lation of the surface ; and an augmentation r the effect 
would evidently result in the crumples shown Fig. 58. 
The appearance of the white seams at those ces where 
a dislocation occurred was, as far as I coulc observe, in- 
variable ; but in a few instances the seams were observed 
upon the platforms of the terraces, and also up <n their slopes. 
The width of a seam was very irregular varying from a 
few inches at some places to three or four feet at others. 

On the 3rd of August I was again at the base of the 
Talefre cascade, and observed a fact the significance of 
which had previously escaped me. The rills which ran 



MOULDS OF WHITE ICE-SEAMS. 417 



down the ic-^iSp-^ elected at the base of each protu- 
berance byto a str whirh, at the time of my visit, had 
hollowec 1 tout for i a deep channel in the ice. At some 
places tul stream iened, at others its banks of ice ap- 
proached e& c h oth .', and rapids were produced ; in fact. 
the channels q/| sue 'treams appeared to be the exact moulds 
of the seams o/Wii ? ice. 

Instructed tftu r, I ascended the Glacier du Geant on 
the 5th of Auglt and then observed on the wrinkles of 
this glacier the . e leaning backwards and forwards of 
the blue veins as t d previously observed upon the 
Talefre. I also noticed on this day that a seam of white 
ice would sometimes open out into two branches, which, 
after remaining for some distance separate, would reunite 
and thus enclose a little glacier-island. At other places 
lateral branches v^re thrown off from the principal seam, 
thus suggesting j ie form of a glacier-rivulet which had 
been fed by tributary branches. On the 7th of August 
I hunted the seams still farther up the glacier ; and found 
them at one place descending a steep ice-hill, being crossed 
by other similar bands, which however were far less white 
and compact. I followed these new bands to their origin, 
and found it to be a system of crevasses formed at the 
summit of the- hill, some of which were filled with snow. 
Lower dow? ^he crevasses closed, and the snow thus 
jammed bet ^n their walls was converted into white ice. 
These seams, -wever, never attained the compactness and 
prominence oi '-be larger ones which had their origin far 
higher up. I ^ir gled out one of the best of the latter, and 
traced it througl ^a'll the dislocation and confusion of the 
ice, until I found it to terminate in a cavity filled with 
snow. 

This was near the base of the seracs, and the streams 
here were abundant. Comparing the shapes of some of 
them with that of the ice-bands lower down the glacier, a 

EE 



418 



STREAMS AND SEAMS. 



striking resemblance was observed. Fig. 60 is the plan of 
a deep-cut channel through which a stream flowed on the 




Fig. 60. 



day to which I now refer. Fig. 61 is the plan of a seam of 
white ice sketched on the same day, low down upon the 




Fig. 61. 

glacier. Instances of this kind might be multiplied ; and 
the result, I think, renders it certain that the white ice- 
seams referred to are due to the filling up of the channels 
of glacier-streams by snow during winter, and the sub- 
sequent compression of the mass to ice during the descent 
of the glacier. I have found such seams at the bases of all 
cascades that 1 have visited ; and in all cases they appear 
to be due to the same cause. The depth to which they 
penetrate the glacier must be profound, or the ablation of 
the ice must be less than what is generally supposed ; for 
the seams formed so high up on the Glacier du Geant may 
be traced low down upon the trunk-stream of the Mer de 
Glace.* 

These observations on the white ice-seams enable us to 
add an important supplement to what has been stated 
regarding the origin of the dirt -bands of the Mer de 

* The more permanent seams may possibly be due to the filling of 
the profound crevasses of the cascade. 



SCALING- OFF BY PRESSURE. 419 

Glace. The protuberances at the base of the cascade are 
due not only to the toning down of the ridges produced 
by the transverse fracture of the glacier at the summit of the 
fall, but they undergo modifications by the pressure locally 
exerted at its base. The state of things represented in 
Fig. 57 is plainly due to the partial pushing of one crumple 
over that next in advance of it. There seems to be a 
differential motion of the parts of the glacier in the same 
longitudinal line ; showing that upon the general motion of 
the glacier smaller local motions are superposed. The occur- 
rence of the seams upon the faces of the slopes seems also 
to prove that the pressure is competent, in some cases, to 
cause the bases of the protuberances to swell, so that what 
was once the base of a crumple may subsequently form a 
portion of its slope. Another interesting fact is also ob- 
served where the pressure is violent : the crumples scale 
off, bows of ice being thus formed which usually span the 
crumples over their most violently compressed portions. 
I have found this scaling off at the bases of all the cascades 
which I have visited, and it is plainly due to the pressure 
exerted at such places upon the ice. 



(33.) 

Not only at the base of its great cascade, but throughout 
the greater part of its length, the Glacier du Geant is in a 
state of longitudinal compression. The meaning of this 
term will be readily understood : Let two points, for ex- 
ample, be marked upon the axis of the glacier ; if these 
during its descent were drawn wider apart, it would show 
that the glacier was in a state of longitudinal strain or 
tension ; if they remained at the same distance apart, it 
would indicate that neither strain nor pressure was exerted ; 
whereas, if the two points approached each other, which 

E E 2 



420 COMPRESSION OF GLACIER DU GEANT. 

could only be by the quicker motion of the hinder one, 
the existence of longitudinal compression would be thereby 
demonstrated. 

Taking " Le Petit Balmat" with me, to carry my theodo- 
lite, I ascended the Glacier du Geant until I came near 
the place where it is joined by the Glacier des Periades, 
and whence I observed a patch of fresh green grass upon 
the otherwise rocky mountain-side. To this point I climbed, 
and made it the station for my instrument. Choosing a 
well-defined object at the opposite side of the glacier, I 
set, on the 9th of August, in the line between this object 
and the theodolite, three stakes, one in the centre of 
the glacier, and the other two at opposite sides of the 
centre and about 100 yards from it. This done, I de- 
scended for a quarter of a mile, when I again climbed 
the flanking rocks, placing my theodolite in a couloir, 
down which stones are frequently discharged from the 
end of a secondary glacier which hangs upon the heights 
above. Here, as before, I fixed three stakes, chiselled 
a mark upon the granite, so as to enable me to find 
the place, and regained the ice without accident. A day 
or two previously we had set out a third line at some 
distance lower down, and I was thus furnished with a 
succession of points along the glacier, the relative motions 
of which would decide whether it was pressed or stretched 
in the direction of its length. On the 10th of August 
Mr. Huxley joined us ; and on the following day we all 
set out for the Glacier du Geant, to measure the progress 
of the stakes which I had fixed there. Hirst remained 
upon the glacier to measure the displacements; I shouldered 
the theodolite ; and Huxley was my guide to the mountain- 
side, sounding in advance of me the treacherous-looking 
snow over which we had to pass. 

Calling the central stake of the highest line No. 1, that 
of the middle line No. 2, and that of the line nearest the 



STRUCTURE IN WHITE ICE-SEAMS. 421 

Tacul No. 3, the following are the spaces moved over by 
these three points in twenty- four hours : 

Inches. Distances asunder. 

No. 1. ... 20-551 545 y ar ds. 
No. 2. 15-43 ' 



No. 3. ... 12-75J 487 yards. 

Here we have the fact which the aspect of the glacier 
suggested. The first stake moves five inches a day more 
than the second, and the second nearly three inches a day 
more than the third. As surmised, therefore, the glacier 
is in a state of longitudinal compression, whereby a portion 
of it 1000 yards in length is shortened at the rate of eight 
inches a day. 

In accordance with this result, the transverse undulations 
of the Glacier du Geant, described in the chapter upon 
Dirt-Bands, shorten as they descend. A series of three of 
them measured along the axis of the glacier on the 6th of 
August, 1857, gave the following respective lengths: 
955 links, 855 links, 770 links, the shortest undulation 
being the farthest from the origin of the undulations. 
This glacier then constitutes a vast ice-press, and en- 
ables us to test the explanation which refers the veined 
structure of the ice to pressure. The glacier itself is 
transversely laminated, as already stated; and in many 
cases a structure of extreme definition and beauty is 
developed in the compressed snow, which constitutes the 
seams of white ice. In 1857 I discovered a well-developed 
lenticular structure in some of these seams. In 1858 I 
again examined them. Clearing away the superficial por- 
tions with my axe, I found, drawn through the body of the 
seams, long lines of blue ice of exquisite definition ; in 
fact, I had never seen the structure so delicately exhibited. 
The seams, moreover, were developed in portions of the 
white ice which were near the centre of the glacier, and 
where consequently filamentous sliding was entirely out of 
the question. 



422 PAETIAL SUMMARY. 



PARTIAL SUMMARY. 

1. GLACIERS are derived from mountain snow, which has 
been consolidated to ice by pressure. 

2. That pressure is competent to convert snow into ice 
has been proved by experiment. 

3. The power of yielding to pressure diminishes as the 
mass becomes more compact ; but it does not cease even 
when the substance has attained the compactness which 
would entitle it to be called ice. 

4. When a sufficient depth of snow collects upon the 
earth's surface, the lower portions are squeezed out by the 
pressure of the superincumbent mass. If it rests upon a 
slope it will yield principally in the direction of the slope, 
and move downwards. 

5. In addition to this, the whole mass slides bodily along 
its inclined bed, and leaves the traces of its sliding on the 
rocks over which it passes, grinding off their asperities, and 
marking them with grooves and scratches in the direction 
of the motion. 

6. In this way the deposit of consolidated and uncon- 
solidated snow which covers the higher portions of lofty 
mountains moves slowly down into an adjacent valley, 
through which it descends as a true glacier, partly by 
sliding and partly by the yielding of the mass itself. 

7. Several valleys thus filled may unite in a single 
valley, the tributary glaciers welding themselves together 
to form a trunk-glacier. 

8. Both the main valley and its tributaries are often 
sinuous, and the tributaries must change their direction to 
form the trunk ; the width of the valley often varies. The 
glacier is forced through narrow gorges, widening after it 
has passed them ; the centre of the glacier moves more 



PARTIAL SUMMARY. 423 

quickly than the sides, and the surface more quickly than 
the bottom ; the point of swiftest motion follows the same 
law as that observed in the flow of rivers, shifting from 
one side of the centre to the other as the flexure of the 
valley changes. 

9. These various effects may be reproduced by experi- 
ments on small masses of ice. The substance may more- 
over be moulded into vases and statuettes. Straight bars 
of it may be bent into rings, or even coiled into knots. 

10. Ice, capable of being thus moulded, is practically 
incapable of being stretched. The condition essential to 
success is that the particles of the ice operated on shall be 
kept in close contact, so that when old attachments have 
been severed new ones may be established. 

1 1 . The nearer the ice is to its melting point in tem- 
perature, the more easily are the above results obtained ; 
when ice is many degrees below its freezing point it is 
crushed by pressure to a white powder, and is not capable 
of being moulded as above. 

12. Two pieces of ice at 32 Fahr., with moist surfaces, 
when placed in contact freeze together to a rigid mass ; 
this is called Regelation. 

13. When the attachments of pressed ice are broken, 
the continuity of the mass is restored by the regelation of 
the new contiguous surfaces. Regelation also enables two 
tributary glaciers to weld themselves to form a continuous 
trunk ; thus also the crevasses are mended, and the dis- 
locations of the glacier consequent on descending cascades 
are repaired. This healing of ruptures extends to the 
smallest particles of the mass, and it enables us to account 
for the continued compactness of the ice during the descent 
of the glacier. 

14. The quality of viscosity is practically absent in 
glacier-ice. Where pressure comes into play the pheno- 
mena are suggestive of viscosity, but where tension comes 



424 .PARTIAL SUMMARY. 

into play the analogy with a viscous body breaks down. 
When subjected to strain the glacier does not yield by 
stretching, but by breaking ; this is the origin of the 
crevasses. 

15. The crevasses are produced by the mechanical strains 
to which the glacier is subjected. They are divided into 
marginal, transverse, and longitudinal crevasses ; the first 
produced by the oblique strain consequent on the quicker 
motion of the centre ; the second by the passage of the 
glacier over the summit of an incline ; the third by 
pressure from behind and resistance in front, which causes 
the mass to split at right angles to the pressure [strain ?]. 

16. The moulins are formed by deep cracks intersecting 
glacier rivulets. The water in descending such cracks scoops 
out for itself a shaft, sometimes many feet wide, and some 
hundreds of feet deep, into which the cataract plunges with 
a sound like thunder. The supply of water is periodically 
cut off from the moulins by fresh cracks, in which new 
moulins are formed. 

17. The lateral moraines are formed from the debris 
which loads the glacier along its edges ; the medial mo- 
raines are formed on a trunk-glacier by the union of the 
lateral moraines of its tributaries ; the terminal moraines 
are formed from the debris carried by the glacier to its 
terminus, and there deposited. The number of medial 
moraines on a trunk glacier is always one less than the 
number of tributaries. 

18. When ordinary lake-ice is intersected by a strong sun- 
beam it liquefies so as to form flower-shaped figures within 
the mass ; each flower consists of six petals with a vacuous 
space at the centre ; the flowers are always formed parallel 
to the planes of freezing, and depend on the crystallization 
of the substance. 

19. Innumerable liquid disks, with vacuous spots, are 
also formed by the solar beams in glacier-ice. These empty 



PARTIAL SUMMARY. 425 

spaces have been hitherto mistaken for air-bubbles, the flat 
form of the disks being erroneously regarded as the result 
of pressure. 

20. These disks are indicators of the intimate constitution 
of glacier-ice, and they teach us that it is composed of an 
aggregate of parts with surfaces of crystallization in all 
possible planes. 

21. There are also innumerable small cells in glacier- 
ice holding air and water ; such cells also occur in lake- 
ice ; and here they are due to the melting of the ice in 
contact with the bubble of air. Experiments are needed 
011 glacier-ice in reference to this point. 

22. At a free surface within or without, ice melts with 
more ease than in the centre of a compact mass. The 
motion which we call heat is less controlled at a free sur- 
face, and it liberates the molecules from the solid condition 
sooner than when the atoms are surrounded on all sides 
by other atoms which impede the molecular motion. 
Regelation is the complementary effect to the above ; for 
here the superficial portions of a mass of ice are made 
virtually central by the contact of a second mass. 

23. The dirt-bands have their origin in the ice-cascades. 
The glacier, in passing the brow, is transversely fractured ; 
ridges are formed with hollows between them ; these trans- 
verse hollows are the principal receptacles of the fine 
debris scattered over the glacier ; and after the ridges have 
been melted away, the dirt remains in successive stripes 
upon the glacier. 

24. The ice of many glaciers is laminated, and when 
weathered may be cloven into thin plates. In the sound 
ice the lamination manifests itself in blue stripes drawn 
through the general whitish mass of the glacier ; these blue 
veins representing portions of ice from which the air- 
bubbles have been more completely expelled. This is the 
veined structure of the ice. It is divided into marginal, 



426 PARTIAL SUMMARY. 

transverse, and longitudinal structure ; which may be 
regarded as complementary to marginal, longitudinal, and 
transverse crevasses. The latter are produced by tension, 
the former by pressure, which acts in two different ways : 
firstly, the pressure acts upon the ice as it has acted upon 
rocks which exhibit the lamination technically called cleav- 
age ; secondly, it produces partial liquefaction of the ice. 
The liquid spaces thus formed help the escape of the air 
from the glacier ; and the water produced, being refrozen 
when the pressure is relieved, helps to form the blue veins. 



APPENDIX. 



COMPARATIVE VIEW OF THE CLEAVAGE OF 
CRYSTALS AND SLATE-ROCKS. 

A LECTURE DELIVEEED AT THE ROYAL INSTITUTION, ON 
FRIDAY EVENING THE 6TH OF JUNE, 1856.* 



WHEN the student of physical science has to investigate the character 
of any natural force, his first care must be to purify it from the mix- 
ture of other forces, and thus study its simple action. If, for example, 
he wishes to know how a mass of water would shape itself, supposing 
it to be at liberty to follow the bent of its own molecular forces, he 
must see that these forces have free and undisturbed exercise. We 
might perhaps refer him to the dew-drop for a solution of the ques- 
tion ; but here we have to do, not only with the action of the molecules 
of the liquid upon each other, but also with the action of gravity upon 
the mass, which pulls the drop downwards and elongates it. If he 
would examine the problem in its purity, he must do as Plateau has 
done, withdraw the liquid mass from the action of gravity, and he 
would then find the shape of the mass to be perfectly spherical. 
Natural processes come to us in a mixed manner, and to the unin- 
structed mind are a mass of unintelligible confusion. Suppose half-a- 
dozen of the best musical performers to be placed in the same room, 
each playing his own instrument to perfection : though each indivi- 
dual instrument might be a well-spring of melody, still the mixture 
of all would produce mere noise. Thus it is with the processes of 
nature. In nature, mechanical and molecular laws mingle, and 
create apparent confusion. Their mixture constitutes what may 
be called the noise of natural laws, and it is the vocation of the 
man of science to resolve this noise into its components, and thus 
to detect the " music " in which the foundations of nature are laid. 
The necessity of this detachment of one force from all other forces 
is nowhere more strikingly exhibited than in the phenomena of 
crystallization. I have here a solution of sulphate of soda. Prolong- 
ing the mental vision beyond the boundaries of sense, we see the atoms 
of that liquid, like squadrons under the eye of an experienced general, 

* Referred to in the Introduction, 



428 APPENDIX. 

arranging themselves into battalions, gathering round a central 
standard, and forming themselves into solid masses, which after a 
time assume the visible shape of the crystal which I here hold in my 
hand. I may, like an ignorant meddler wishing to hasten matters, in- 
troduce confusion into this order. I do so by plunging this glass rod 
into the vessel. The consequent action is not the pure expression of 
the crystalline forces ; the atoms rush together with the confusion 
of an unorganized mob, and not with the steady accuracy of a disci- 
plined host. Here, also, in this mass of bismuth we have an example 
of this confused crystallization ; but in the crucible behind me a 
slower process is going on : here there is an architect at work " who 
makes no chips, no din," and who is now building the particles into 
crystals, similar in shape and structure to those beautiful masses 
which we see upon the table. By permitting alum to crystallize in 
this slow way, we obtain these perfect octahedrons ; by allowing 
carbonate of lime to crystallize, nature produces these beautiful rhom- 
boids; when silica crystallizes, we have formed these hexagonal prisms 
capped at the ends by pyramids ; by allowing saltpetre to crystallize, 
we have these prismatic masses ; and when carbon crystallizes, we 
have the diamond. If we wish to obtain a perfect crystal, we must 
allow the molecular forces free play : if the crystallizing mass be per- 
mitted to rest upon a surface it will be flattened, and to prevent this 
a small crystal must be so suspended as to be surrounded 011 all sides 
by the liquid, or, if it rest upon the surface, it must be turned daily 
so as to present all its faces in succession to the working builder. In 
this way the scientific man nurses these children of his intellect, 
watches over them with a care worthy of imitation, keeps all influ- 
ences away which might possibly invade the strict morality of 
crystalline laws, and finally sees them developed into forms of sym- 
metry and beauty which richly reward the care bestowed upon them. 
In building up crystals, these little atomic bricks often arrange 
themselves into layers which are perfectly parallel to each other, and 
which can be separated by mechanical means ; this is called the 
cleavage of the crystal. I have here a crystallized mass which has 
thus far escaped the abrading and disintegrating forces which, sooner 
or later, determine the fate of sugar-candy. If I am skilful enough, 
I shall discover that this crystal of sugar cleaves with peculiar facility 
in one direction. Here, again, I have a mass of rock-salt : I lay my 
knife upon it, and with a blow cleave it in this direction ; but I find on 
further examining this substance that it cleaves in more directions than 
one. Laying my knife at right angles to its former position, the crystal 
cleaves again ; and, finally placing the knife at right angles to the 



APPENDIX. 429 

two former positions, the mass cleaves again. Thus rock-salt cleaves 
in three directions, and the resulting solid is this perfect cube, which 
may be broken up into any number of smaller cubes. Here is a mass 
of Iceland spar, which also cleaves in three directions, not at right 
angles, but obliquely to each other, the resulting solid being a rhom- 
boid. In each of these cases the mass cleaves with equal facility in 
all three directions. For the sake of completeness, I may say that 
many substances cleave with unequal facility in different directions, 
and the heavy spar I hold in my hand presents an example of this 
kind of cleavage. 

Turn we now to the consideration of some other phenomena to 
which the term cleavage may be applied. This piece of beech- wood 
cleaves with facility parallel to the fibre, and if our experiments were 
fine enough we should discover that the cleavage is most perfect when 
the edge of the axe is laid across the rings which mark the growth 
of the tree. The fibres of the wood lie side by side, and a compara- 
tively small force is sufficient to separate them. If you look at this 
mass of hay severed from a rick, you will see a sort of cleavage de- 
veloped in it also ; the stalks lie in parallel planes, and only a small 
force is required to separate them laterally. But we cannot regard 
the cleavage of the tree as the same in character as the cleavage of 
the hayrick. In the one case it is the atoms arranging themselves 
according to organic laws which produce a cleavable structure ; in the 
other case the easy separation in a certain direction is due to the me- 
chanical arrangement of the coarse sensible masses of the stalks of hay. 

In like manner I find that this piece of sandstone cleaves parallel 
to the planes of bedding. This rock was once a powder, more or less 
coarse, held in mechanical suspension by water. The powder was 
composed of two distinct parts, fine grains of sand and small plates 
of mica. Imagine a wide strand covered by a tide which holds such 
powder in suspension : * how will it sink ? The rounded grains of 
sand will reach the bottom first, the mica afterwards, and when the 
tide recedes we have the little plates shining like spangles upon the 
surface of the sand. Each successive tide brings its charge of mixed 
powder, deposits its duplex layer day after day, and finally masses 
of immense thickness are thus piled up, which, by preserving the 
alternations of sand and mica, tell the tale of their formation. I do 
not wish you to accept this without proof. Take the sand and mica, 
mix them together in water, and allow them to subside, they will 

* I merely use this as an illustration ; the deposition may have really 
been due to sediment carried down by rivers. But the action must have 
been periodic, and the powder duplex. 



430 APPENDIX. 

arrange themselves in the manner I have indicated ; and by repeat- 
ing the process you can actually build up a sandstone mass which 
shall be the exact counterpart of that presented by nature, as I have 
done in this glass jar. Now this structure cleaves with readiness 
along the planes in which the particles of mica are strewn. Here 
is a mass of such a rock sent to me from Halifax : here are other 
masses from the quarries of Over Darwen in Lancashire. With a 
hammer and chisel you see I can cleave them into flags ; indeed these 
flags are made use of for roofing purposes in the districts from which 
the specimens have come, and receive the name of "slate -stone." 
But you will discern, without a word from me, that this cleavage is 
not a crystalline cleavage any more than that of a hayrick is. It 
is not an arrangement produced by molecular forces; indeed it 
would be just as reasonable to suppose that in this jar of sand and 
mica the particles arranged themselves into layers by the forces of 
crystallization, instead of by the simple force of gravity, as to 
imagine that such a cleavage as this could be the product of crystal- 
lization. 

This, so far as I am aware of, has never been imagined, and it has 
been agreed among geologists not to call such splitting as this 
cleavage at all, but to restrict the term to a class of phenomena 
which I shall now proceed to consider. 

Those who have visited the slate quarries of Cumberland and 
North Wales will have witnessed the phenomena to which I refer. 
We have long drawn our supply of roofing- slates from such quarries ; 
schoolboys ciphered on these slates, they were used for tombstones 
in churchyards, and for billiard-tables in the metropolis ; but not 
until a comparatively late period did men begin to inquire how 
their wonderful structure was produced. What is the agency which 
enables us to split Honister Crag, or the cliffs of Snowdon, into 
laminsB from crown to base? This question is at the present 
moment one of the greatest difficulties of geologists, and occupies 
their attention perhaps more than any other. You may wonder at 
this. Looking into the quarry of Penrhyn, you may be disposed to 
explain the question as I heard it explained two years ago. " These 
planes of cleavage," said a friend who stood beside me on the 
quarry's edge, " are the planes of stratification which have been lifted 
by some convulsion into an almost vertical position." But this was 
a great mistake, and indeed here lies the grand difficulty of the pro- 
blem. These planes of cleavage stand in most cases at a high angle 
to the bedding. Thanks to Sir Eoderick Murchison, who has kindly 
permitted me the use of specimens from the Museum of Practical 



APPENDIX. 431 

Geology (and here I may be permitted to express my acknowledg- 
ments to the distinguished staff of that noble establishment, who, 
instead of considering me an intruder, have welcomed me as a 
brother), I am able to place the proof of this before you. Here is a 
mass of slate in which the planes of bedding are distinctly marked ; 
here are the planes of cleavage, and you see that one of them makes 
a large angle with the other. The cleavage of slates is therefore not 
a question of stratification, and the problem which we have now to 
consider is, " By what cause has this cleavage been produced ? " 

In an able and elaborate essay on this subject in 1835, Professor 
Sedgwick proposed the theory that cleavage is produced by the action 
of crystalline or polar forces after the mass has been consolidated. 
" We may affirm," he says, " that no retreat of the parts, no con- 
traction of dimensions in passing to a solid state can explain such 
phenomena. They appear to me only resolvable on the supposition 
that crystalline or polar forces acted upon the whole mass simul- 
taneously in one direction and with adequate force." And again, 
in another place : " Crystalline forces have rearranged whole moun- 
tain-masses, producing a beautiful crystalline cleavage, passing alike 
through all the strata." * The utterance of such a man struck deep, 
as was natural, into the minds of geologists, and at the present day 
there are few who do not entertain this view either in whole or in part.f 
The magnificence of the theory, indeed, has in some cases caused 
speculation to run riot, and we have books published, aye and largely 
sold, on the action of polar forces and geologic magnetism, which 
rather astonish those who know something about the subject. Ac- 
cording to the theory referred to, miles and miles of the districts of 
North Wales -and Cumberland, comprising huge mountain-masses, 
are neither more nor less than the parts of a gigantic crystal. These 
masses of slate were originally fine mud ; this mud is composed of 
the broken and abraded particles of older rocks. It contains silica, 

* ' Transactions of the Geological Society, 1 Ser. ii. vol. iii. p. 477. 

f In a letter to Sir Charles Lyell, dated from the Cape of Good Hope, 
February 20, 1836, Sir John Herschel writes as follows : " If rocks have 
been so heated as to allow of a commencement of crystallization, that is 
to say, if they have been heated to a point at which the particles can 
begin to move amongst themselves, or at least on their own axes, some 
general law must then determine the position in which these particles 
will rest on cooling. Probably that position will have some relation to 
the direction in which the heat escapes. Now when all or a majority of 
particles of the same nature have a general tendency to one position, that 
must of course determine a cleavage plane." 



432 APPENDIX. 

alumina, iron, potash, soda, and mica, mixed in sensible masses 
mechanically together. In the course of ages the mass became con- 
solidated, and the theory before us assumes that afterwards a process 
of crystallization rearranged the particles and developed in the mass 
a single plane of crystalline cleavage. With reference to this hypo- 
thesis, I will only say that it is a bold stretch of analogies ; but still 
it has done good service : it has drawn attention to the question ; 
right or wrong, a theory thus thoughtfully uttered has its value ; it 
is a dynamic power which operates against intellectual stagnation ; 
and, even by provoking opposition, is eventually of service to the 
cause of truth. It would, however, have been remarkable, if, among 
the ranks of geologists themselves, men were not found to seek an 
explanation of the phenomena in question, which involved a less 
hardy spring on the part of the speculative faculty than the view to 
which I have just referred. 

The first step in an inquiry of this kind is to put oneself into con- 
tact with nature, to seek facts. This has been done, and the labours 
of Sharpe (the late President of the Geological Society, who, to the 
loss of science and the sorrow of all who knew him, has so suddenly 
been taken away from us), Sorby, and others, have furnished us with 
a body of evidence which reveals to us certain important physical 
phenomena, associated with the appearance of slaty cleavage, if they 
have not produced it. The nature of this evidence we will now pro- 
ceed to consider. 

Fossil shells are found in these slate-rocks. I have here several 
specimens of such shells, occupying various positions with regard to 
the cleavage planes. They are squeezed, distorted, and crushed. In 
some cases a flattening of the convex shell occurs, in others the 
valves are pressed by a force which acted in the plane of their junc- 
tion, but in all cases the distortion is such as leads to the inference 
that the rock which contains these shells has been subjected to 
enormous pressure in a direction at right angles to the planes of 
cleavage ; the shells are all flattened and spread out upon these 
planes. I hold in my hand a fossil trilobite of normal proportions. 
Here is a series of fossils of the same creature which have suffered 
distortion. Some have lain across, some along, and some oblique 
to the cleavage of the slate in which they are found ; in all cases the 
nature of the distortion is such as required for its production a com- 
pressing force acting at right angles to the planes of cleavage. As 
the creatures lay in the mud in the manner indicated, the jaws of 
a gigantic vice appear to have closed upon them and squeezed them 
into the shape you see. As further evidence of the exertion of 



APPENDIX. 433 

pressure, let me introduce to your notice a case of contortion which 
has been adduced by Mr. Sorby. The bedding of the rock shown in 
this figure* was once horizontal; at A we have a deep layer of mud, 
and at m n a layer of comparatively unyielding gritty material ; 
below that again, at B, we have another layer of the fine mud of 
which slates are formed. This mass cleaves along the shading lines 
of the diagram ; but look at the shape of the intermediate bed : it 
is contorted into a serpentine form, and leads irresistibly to the 
conclusion that the mass has been pressed together at right angles 
tor the planes of cleavage. This action can be experimentally imi- 
tated, and I have here a piece of clay in which this is done and the 
same result produced on a small scale. The amount of compression, 
indeed, might be roughly estimated by supposing this contorted bed 
m n to be stretched out, its length measured and compared with the 
distance c d ; we find in this way that the yielding of the mass has 
been considerable. 

Let me now direct your attention to another proof of pressure. 
You see the varying colours which indicate the bedding on this mass 
of slate. The dark portion, as I have stated, is gritty, and composed 
of comparatively coarse particles, which, owing to their size, shape, 
and gravity, sink first and constitute the bottom of each layer. 
Gradually from bottom to top the coarseness diminishes, and near 
the upper surface of each layer we have a mass of comparatively 
fine clean mud. Sometimes this fine mud forms distinct layers in 
c i mass of slate-rock, and it is the mud thus consolidated from which 
are derived the German razor-stones, so much prized for the sharpen- 
ing of surgical instruments. I have here an example of such a 
stone. When a bed is thin, the clean white mud is permitted to rest, 
as in this case, upon a slab of the coarser slate in contact with it : 
when the bed is thick, it is cut into slices which are cemented to 
pieces of ordinary slate, and thus rendered stronger. The mud thus 
deposited sometimes in layers is, as might be expected, often rolled 
up into nodular masses, carried forward, and deposited by the rivers 
from which the slate-mud has subsided. Here, indeed, are such 
nodules enclosed in sandstone. Everybody who has ciphered upon 
a school-slate must remember the whitish-green spots which some- 
times dotted the surface of the slate ; he will remember how his 
slate-pencil usually slid over such spots as if they were greasy. Now 
these spots are composed of the finer mud, and they could not, on 
account of their fineness, bite the pencil like the surrounding gritty 
portions of the slate. Here is a beautiful example of the spots : you 
* Omitted here. 



434 APPENDIX. 

observe them on the cleavage surface in broad patches ; but if this 
mass has been compressed at right angles to the planes of cleavage, 
ought we to expect the same marks when we look at the edge of the 
slab ? The nodules will be flattened by such pressure, and we ought 
to see evidence of this flattening when we turn the slate edgeways. 
Here it is. The section of a nodule is a sharp ellipse with its major 
axis parallel to the cleavage. There are other examples of the same 
nature on the table ; I have made excursions to the quarries of 
Wales and Cumberland, and to many of the slate-yards of London, 
but the same fact invariably appears, and thus we elevate a common 
experience of our boyhood into evidence of the highest significance 
as regards one of the most important problems of geology. In ex- 
amining the magnetism of these slates, I was led to infer that these 
spots would contain a less amount of iron than the surrounding 
dark slate. The analysis was made for me by Mr. Hambly in the 
laboratory of Dr. Percy at the School of Mines. The result which 
is stated in this Table justifies the conclusion to which I have 
referred. 

Analysis of Slate. 

Purple Slate. Two Analyses. 

1. Percentage of iron .' . . 5*85 

2. . . . 6-13 

Mean . . . 5-99 

Greenish Slate. 

1. Percentage of iron . , t . 3-24 

2. 3-12 



Mean . . . 3-18 

The quantity of iron in the dark slate immediately adjacent to the 
greenish spot is, according to these analyses, nearly double of the 
quantity contained in the spot itself. This is about the proportion 
which the magnetic experiments suggested. 

Let me now remind you that the facts which I have brought 
before you are typical facts each is the representative of a class. 
We have seen shells crushed, the unhappy trilobites squeezed, beds 
contorted, nodules of greenish marl flattened ; and all these sources 
of independent testimony point to one and the same conclusion, 
namely, that slate-rocks have been subjected to enormous pressure 
in a direction at right angles to the planes of cleavage.* 

* While to my mind the evidence in proof of pressure seems per- 
fectly irresistible, I by no means assert that the manner in which I stated 



APPENDIX. 435 

In reference to Mr. Sorby's contorted bed, I have said that by 
supposing it to be stretched out and its length measured, it would 
give us an idea of the amount of yielding of the mass above and 
below the bed. Such a measurement, however, would not quite 
give the amount of yielding ; and here I would beg your attention 
to a point, the significance of which has, so far as I am aware of, 
hitherto escaped attention. I hold in my hand a specimen of slate, 
with its bedding marked upon it ; the lower portions of each bed 
are composed of a comparatively coarse gritty material, something 
like what you may suppose this contorted bed to be composed of. 
Well, I find that the cleavage takes a bend in crossing these gritty 
portions, and that the tendency of these portions is to cleave more 
at right angles to the bedding. Look to this diagram : when the 
forces commenced to act, this intermediate bed, which though 
comparatively unyielding is not entirely so, suffered longitudinal 
pressure ; as it bent, the pressure became gradually more lateral, 
and the direction of its cleavage is exactly such as you would infer 
from a force of this kind it is neither quite across the bed, nor yet 
in the same direction as the cleavage of the slate above and below 
it, but intermediate between the two. Supposing the cleavage to be 
at right angles to the pressure, this is the direction which it ought 
to take across these more unyielding strata. 

Thus we have established the concurrence of the phenomena 01 
cleavage and pressure that they accompany each other ; but the 
question still remains, Is this pressure of itself sufficient to account 
for the cleavage ? A single geologist, as far as I am aware, answers 
boldly in the affirmative. This geologist is Sorby, who has attacked 
the question in the true spirit of a physical investigator. You remem- 
ber the cleavage of the flags of Halifax and Over Darwen, which 
is caused by the interposition of plates of mica between the layers. 
Mr. Sorby examines the structure of slate-rock, and finds plates of 
mica to be a constituent. He asks himself, what will be the effect 
of pressure upon a mass containing such plates confusedly mixed up 
in it ? It will be, he argues and he argues rightly to place the 
plates with their flat surfaces more or less perpendicular to the 
direction in which the pressure is exerted. He takes scales of the 
oxide of iron, mixes them with a fine powder, and, on squeezing 

it is incapable of modification. All that I deem important is the fact 
that pressure has been exerted ; and provided this remain firm, the 
fate of any minor portion of the evidence by which it is here established 
is of comparatively little moment. 



436 APPENDIX. 

the mass, finds that the tendency of the scales is to set themselves 
at right angles to the line of pressure. Now the planes in which 
these plates arrange themselves will, he contends, be those along 
which the mass cleaves. 

I could show you, by tests of a totally different character from 
those applied by Mr. Sorby, how true his conclusion is, that the 
effect of pressure on elongated particles or plates will be such as he 
describes it. Nevertheless, while knowing this fact, and admiring 
the ability with which Mr. Sorby has treated this question, I cannot 
accept his explanation of slate-cleavage. I believe that even if these 
plates of mica were wholly absent, the cleavage of slate-rocks would 
be much the same as it is at present. 

I will not dwell here upon minor facts, I will not urge that 
the perfection of the cleavage bears no relation to the quantity of 
mica present ; but I will come at once to a case which to my mind 
completely upsets the notion that such plates are a necessary element 
in the production of cleavage. 

Here is a mass of pure white wax : there are no mica particles 
here ; there are no scales of iron, or anything analogous mixed up 
with the mass. Here is the self-same substance submitted to 
pressure. I would invite the attention of the eminent geologists 
whom I see before me to the structure of this mass. No slate ever 
exhibited so clean a cleavage ; it splits into laminae of surpassing 
tenuity, and proves at a single stroke that pressure is sufficient to 
produce cleavage, and that this cleavage is independent of the inter- 
mixed plates of mica assumed in Mr. Sorby's theory. I have pur- 
posely mixed this wax with elongated particles, and am unable to 
say at the present moment that the cleavage is sensibly affected by 
their presence, if anything, I should say they rather impair its 
fineness and clearness than promote it. 

The finer the slate the more perfect will be the resemblance of 
its cleavage to that of the wax. Compare the surface of the wax 
with the surface of this slate from Borrodale in Cumberland. You 
have precisely the same features in both : you see flakes clinging 
to the surfaces of each, which have been partially torn away by 
the cleavage of the mass : I entertain the conviction that if any 
close observer compares these two effects, he will be led to the con- 
clusion that they are the product of a common cause.* 

* I have usually softened the wax by warming it, kneaded it with 
the fingers, and pressed it between thick plates of glass previously 
wetted. At the ordinary summer-temperature the wax is soft, and tears 
rather than cleaves; on this account I cool my compressed specimens in 



APPENDIX. 437 

But you will ask, how, according to my view, does pressure pro- 
duce this remarkable result ? This may be stated in a very few 
words. 

Nature is everywhere imperfect! The eye is not perfectly 
achromatic, the colours of the rose and tulip are not pure colours, 
and the freshest air of our hills has a bit of poison in it. In like 
manner there is no such thing in nature as a body of perfectly 
homogeneous structure. I break this clay which seems so inti- 
mately mixed, and find that the fracture presents to my eyes 
innumerable surfaces along which it has given way, and it has 
yielded along these surfaces because in them the cohesion of the 
mass is less than elsewhere. I break this marble, and even this 
wax, and observe the same result : look at the mud at the bottom 
of a dried pond ; look to some of the ungravelled walks in Kensing- 
ton Gardens on drying after rain, they are cracked and split, and 
other circumstances being equal, they crack and split where the 
cohesion of the mass is least. Take then a mass of partially con- 
solidated mud. Assuredly such a mass is divided and subdivided 
by surfaces along which the cohesion is comparatively small. 
Penetrate the mass, and you will see it composed of numberless 
irregular nodules bounded by surfaces of weak cohesion. Figure 
to your mind's eye such a mass subjected to pressure, the mass 
yields and spreads out in the direction of least resistance ; * the 
little nodules become converted into laminae, separated from each 
other by surfaces of weak cohesion, and the infallible result will be 
that such amass will cleave at right angles to the line in which the 
pressure is exerted. 

Further, a mass of dried mud is full of cavities and fissures. If 
you break dried pipe-clay you see them in great numbers, and there 
are multitudes of them so small that you cannot see them. I have 
here a piece of glass in which a bubble was enclosed ; by the com- 
pression of the glass the bubble is flattened, and the sides of the 
bubble approach each other so closely as to exhibit the colours of 
thin plates. A similar flattening of the cavities must take place in 
squeezed mud, and this must materially facilitate the cleavage of 
the mass in the direction already indicated. 

Although the time at my disposal has not permitted me to develop 

a mixture of pounded ice and salt, and when thus cooled they split 
beautifully. 

* It is scarcely necessary to say that if the mass were squeezed equally 
in all directions no laminated structure could be produced ; it must have 
room to yield in a lateral direction. 



438 APPENDIX. 

this thought as far as I could wish, yet for the last twelve months 
the subject has presented itself to me almost daily under one aspect 
or another. I have never eaten a biscuit during this period in which 
an intellectual joy has not been superadded to the more sensual 
pleasure, for I have remarked in all such cases cleavage developed 
in the mass by the rolling-pin of the pastrycook or confectioner. I 
have only to break these cakes, and to look at the fracture, to see 
the laminated structure of the mass ; nay, I have the means of 
pushing the analogy further : I have here some slate which was 
subjected to a high temperature during the conflagration of Mr. 
Scott Bussell's premises. I invite you to compare this structure 
with that of a biscuit ; air or vapour within the mass has caused it 
to swell, and the mechanical structure it reveals is precisely that 
of a biscuit. I have gone a little into the mysteries of baking while 
conducting my inquiries on this subject, and have received much 
instruction from a lady-friend in the manufacture of puff-paste. 
Here is some paste baked in this house under my own superinten- 
dence. The cleavage of our hills is accidental cleavage, but this is 
cleavage with intention. The volition of the pastrycook has entered 
into the formation of the mass, and it has been his aim to preserve 
a series of surfaces of structural weakness, along which the dough 
divides into layers. Puff-paste must not be handled too much, for 
then the continuity of the surfaces is broken ; it ought to be rolled 
on a cold slab, to prevent the butter from melting and diffusing 
itself through the mass, thus rendering it more homogeneous and 
less liable to split. This is the whole philosophy of puff-paste ; it 
is a grossly exaggerated case of slaty cleavage. 

As time passed on, cases multiplied, illustrating the influence of 
pressure in producing lamination. Mr. Warren De la Hue informs 
me that he once wished to obtain white-lead in a fine granular state, 
and to accomplish this he first compressed the mass : the mould 
was conical, and permitted the mass to spread a little laterally under 
the pressure. The lamination was as perfect as that of slate, and 
quite defeated him in his effort to obtain a granular powder. Mr. 
Brodie, as you are aware, has recently discovered a new kind of 
graphite : here is the substance in powder, of exquisite fineness. 
This powder has the peculiarity of clinging together in little con- 
federacies ; it cannot be shaken asunder like lycopodium ; and when 
the mass is squeezed, these groups of particles flatten, and a perfect 
cleavage is produced. Mr. Brodie himself has been kind enough to 
furnish me with specimens for this evening's lecture. I will cleave 
them before you : you see they split up into plates which are per- 



APPENDIX. 439 

pendicular to the line in which the pressure was exerted. This 
testimony is all the more valuable, as the facts were obtained with- 
out any reference whatever to the question of cleavage. 

I have here a mass of that singular substance Boghead Cannel. 
This was once a mass of mud, more or less resembling this one, 
which I have obtained from a bog in Lancashire. I feel some 
hesitation in bringing this substance before you, for, as in other 
cases, so in regard to Boghead Cannel, science not science, let me 
not libel it, but the quibbling, litigious, money-loving portion of 
human nature speaking through the mask of science has so con- 
trived to split hairs as to render the qualities of the substance 
somewhat mythical. 1 shall therefore content myself with showing 
you how it cleaves, and with expressing my conviction that pressure 
had a great share in the production of this cleavage. 

The principle which I have enunciated is so simple as to be 
almost trivial ; nevertheless, it embraces not only the cases I have 
mentioned, but, if time permitted, I think I could show you that it 
takes a much wider range. When iron is taken from the puddling 
furnace, it is a more or less spongy mass : it is at a welding heat, 
and at this temperature is submitted to the process of rolling : 
bright smooth bars such as this are the result of this rolling. But 
I have said that the mass is more or less spongy or nodular, and, 
notwithstanding the high heat, these nodules do not perfectly 
incorporate with their neighbours : what then ? You would say 
that the process of rolling must draw the nodules into fibres it 
does so ; and here is a mass acted upon by dilute sulphuric acid, 
which exhibits in a striking manner this fibrous structure. The 
experiment was made by my friend Dr. Percy, without any reference 
to the question of cleavage. 

Here are other cases of fibrous iron. This fibrous structure is 
the result of mechanical treatment. Break a mass of ordinary iron 
and you have a granular fracture ; beat the mass, you elongate 
these granules, and finally render the mass fibrous. Here are 
pieces of rails along which the wheels of locomotives have slidden ; 
the granules have yielded and become plates ; they exfoliate or 
come off in leaves. All these effects belong, I believe, to the great 
class of phenomena of which slaty cleavage forms the most 
prominent example.* 

* An eminent authority informs me that he believes these surfaces 
of weak cohesion to be due to the interposition of films of graphite, and 
not to any tendency of the iron itself to become fibrous : this of course 
does not in any way militate against the theory which I have ventured 



440 APPENDIX. 

Thus, ladies and gentlemen, we have reached the termination 
of our task. I commenced by exhibiting to you some of the phe- 
nomena of crystallization. I have placed before you the facts which 
are found to be associated with the cleavage of slate-rocks. These 
facts, as finely expressed by Heluiholtz, are so many telescopes 
to our spiritual vision, by which we can see backward through 
the night of antiquity, and discern the forces which have been in 
operation upon the earth's surface 

" Ere the lion roared, 
Or the eagle soared." . 

From evidence of the most independent and trustworthy cha- 
racter, we come to the conclusion that these slaty masses have been 
subjected to enormous pressure, and by the sure method of experi- 
ment we have shown and this is the only really new point which 
has been brought before you how the pressure is sufficient to pro- 
duce the cleavage. Expanding our field of view, we find the 
self-same law, whose footsteps we trace amid the crags of Wales 
and Cumberland, stretching its ubiquitous fingers into the domain 
of the pastrycook and ironfounder ; nay, a wheel cannot roll over 
the half- dried mud of our streets without revealing to us more or 
less of the features of this law. I would say, in conclusion, that 
the spirit in which this problem has been attacked by geologists 
indicates the dawning of a new day for their science. The great 
intellects who have laboured at geology, and who have raised it to 
its present pitch of grandeur, were compelled to deal with the sub- 
ject in mass ; they had no time to look after details. But the desire 
for more exact knowledge is increasing ; facts are flowing in, which, 
while they leave untouched the intrinsic wonders of geology, are 
gradually supplanting by solid truths the uncertain speculations 
which beset the subject in its infancy. Geologists now aim to imi- 
tate, as far as possible, the conditions of nature, and to produce her 
results ; they are approaching more and more to the domain of 
physics ; and I trust the day will soon come when we shall interlace 
our friendly arms across the common boundary of our sciences, 
and pursue our respective tasks in a spirit of mutual helpfulness, 
encouragement, and good-will. 

to propose. All that the theory requires is surfaces of weak cohesion, 
however produced, and a change of shape of such surfaces consequent 
on pressure or rolling. 



441 

INDEX. 



^GGISCHHOEN. 

JEggischhorn, 100, 105. 

Agassiz on glacier motion, 270, 

310. 

Air-bubbles, 359, 376. 
Aletsch Glacier, 101. 

, bedding and structure ob- 
served on, 120, 391. 
Alefcschhorn, cloud iridescences on, 

LOO, 238. 

Allalein Glacier, 162. 
Alpine climbers, suggestions to, 

169. 

Alps, winter temperature of, 168. 
Altmann's theory of glacier motion, 

296. 

Ancient glaciers, action of, 99, 141. 
Arveiron, arch of, 38, 217. 
Atmosphere, permeability of, to 

radiant heat, 105, 243-247. 
Atmospheric refraction, 35. 
Avalanche at Saas, 164. 
, sound of, explained, 12, 14. 

Bakewell, Mr., on motion of Glacier 

des Bossons, 337. 
Balmat, Auguste, 169, 188. 
Bedding, lines of, 391. 
Bennen, Johann Joseph, 104, 118. 
Bergschrund, 98, 325. 
"Blower," glacier, 87. 
Blue colour of ice, 256. 

snow, 29, 83, 132, 203. 
- water, 33, 253, 259-262. 
Blueness of sky, 22, 174, 257-261. 
Blue veins, 376, 381. 
Boiling-point, influence of pressure 
on, 408. 

at different altitudes, 105, 
106, 113, 120, 129, 175, 
190. 

Bois, Glacier des, 39, 275, 368. 
Brevent, ascent of, 172. 
Brocken, Spirit of the, 22, 238. 
Bubbles in ice, 44, 147, 359, 425. 
in snow, 18, 251. 



CEYSTALS. 

Capillaries of glacier, 335-339. 

Cave of ice, 135. 

Cavities in ice, 163, 356, 424. 

Cells in ice, 147, see Bubbles. 

Chamouni, 37. 

, difficulties at, 170, 192. 

in winter, 198, 336. 
Charmoz, view from, 45, 68, 368. 
Charpentier's theory of glacier mo- 
tion, 296. 

Chemical action, rays producing, 

240. 

Chromatic effects, 235. 
Cleavage, 406. 

and stratification distinct, 2, 

390, 431. 

caused by pressure, 6, 436. 
, contortions of, 9, 59. 

of crystals and slate rocks, 

lecture on, 427. 

- of glaciers, 26, 393, 425-426. 
ice, 352, 407. 

slate, &c., 1, 430. 

" Cleft station," the, 47, 369. 
Clouds, formation and dissipation 

of, 22, 97, 137, 146. 
, iridescent, 100, 105, 147. 154, 
238. 

on Mont Blanc, 82. 

on Monte Bosa, 124. 

, winter, at Montanvert, 208. 
Colour answers to pitch, 227. 
Colours of sky, 257. 
, subjective, 37. 
Comet, discovery of, 186. 
Compass affected by rocks, 140. 
Crepitation of glaciers, 44, 357. 
Crevasses, 315 (marginal, 318 ; 

transverse, 320 ; longitudinal, 

322), 424. 

, first opening of, 317, 327. 
Crumples in ice, 174, 415, 419. 
Crystallization of ice, 353. 
Crystals, cleavage of, 3, 428. 

of snow, 130, 205, 212. 



442 



INDEX. 



DEAFNESS. 

Deafness, artificial, 167. 
Differential motion, 395. 

, Dr. Whewell on, 396. 
Diffraction, explanation of, 237. 
Dirt-bands, 45, 46, 68, 95, 367, 373. ' 

maps of, 367, 368, 369. 
, Forbes on, 371. 

, source of, 369, 425. 
Disks in ice, planes of, 163, 358, 

425. 

Dollfuss, M., hut of, 18, 112. 
Dome du Gouter, 68, 75. 
Donny, M., on cohesion of liquids, 

355. 

Echoes, theory of, 15. 
Eismeer, the, 13, 362. 
Expedition of 1856, Oberland and 
Tyrol, 9-32. 

1857, Montanvert and Mer 

de Glace, 33-91. 

1858, Oberland, Valais, and 

Monte Kosa district, 92- 
192. 

1859, winter, Chamouni, and 

Mer de Glace, 195-219. 

Faraday, Prof., on Eegelation, 351. 

Faulberg, cave of, 107. 

Fee, glacier of, 165. 

Fend, 32. 

Finsteraarhorn, 104, 110. 

, summit of, 112. 

Flowers, liquid, in ice, 147, 354- 

358, 424. 
Forbes, Prof., comparison of glacier 

to river, 306, 308. 
, on glacier motion, 272, 304, 
308. 

, on magnetism of rocks, 145. 

, on veined structure, 379. 

, viscous theory, 311, 327, 

333, 335. 

Freezing, planes of, 163, 358, 424. 
Frost-bites, 191. 
Frozen flowers, 130, 212. 
Furgge glacier, structure crossing 

strata on, 160, 392-394. 

Gases, passage of heat through, 

243. 
Geant, Col du, 50, 173. 



HANDECK. 

G6ant, glacier du, 53-57, 280, 369- 

373. 

, measurements on, 419-421. 
, motion of, 281, 286. 
, white ice seams of, 56, 413. 
Gebatsch Alp, 23. 
, glacier of, 24, 26. 
Geneva, Lake of, 33, 259-262. 
' Glaciers, ancient, action of, 99, 163. 

" blower," 87. 

, capillaries of, 335-339. 
, crepitation of, 44, 357. 

d'ecoulement, 301. 

de L6chaud, see Le'chaud. 

- des Bois, 39, 275, 368. 

du Geant, see Geant. 

- du Talefre, see Talefre. 
, groovings on, 20, 56, 377. 
, measurement of, 276. 

motion, 52, 269-295, 422. 
, earlier theories of, 296-314. 

, pressure theory of, 346. 
, origin of, 248-252. 

reservoirs, 301. 
, ridges on, 42, 55. 

, structure of, 136, 148, see 
Veined structure. 

tables, 44, 265. 

, veins of, 54, 376, 381. 

, wrinkles on, 370. 

Goethe's theory of colours, 258. 

Gorner glacier, 120, 138. 

Gorner grat, 137, 145. 

Gornerhorn glacier, 147, 149. 

Grand Plateau, 187. 

Grands Mulcts, 73, 185. 

Graun, 29. 

Grimsel, the, 18, 99. 

Grindelwald, lower glacier of, 13, 

92, 321, 384. 

Groovings on glaciers, 20, 56, 377. 
Griiner's theory of glacier motion, 

296. 
Guides of Chamouni, rules of, 60, 

170, 192. 

lost in crevasse, 76. 

Guyot, M., on veined structure, 
378. 

Hailstones, conical, 31. 
, spherical, 65. 
Handeck, waterfall of, 17. 



INDEX. 



443 



Hasli, valley of, 17, 99. 
Heat and light, 223, 239, 241. 

work, 328. 

, luminous, 241-247. 

, mechanical equivalent of, 329. 

, obscure, 240. 

, passage through gases, 243-245. 

, radiant, 239. 

, permeability of atmosphere 

to, 105, 243-247. 
, radiated, 242. 
, specific, 331. 
Heisse Platte, the, 13. 
Hirst, Mr., measurements on Mer 

de Glace, 38, 46, 275, 283, 289, 

313,420. 
Hoch-joch, 32. 

Hochste Spitze of Monte Rosa, 128. 
Hopkins, Mr., on crevasses, 318, 

383. 
Hotel des Neufchatelois, 19, 112, 

270. 

Hugi on glacier motion, 270. 
Huxley, Mr., on glacier capillaries, 

338. 

, on water-cells, 251, 359. 
Hydrogen, effect on rays, 253. 

Ice, blue colour of, 256. 

cascades, 94, 384, 391. 

cave, 135. 

cells, 147, see Bubbles. 

cones, 266. 

, cracking of, 317, 326. 
, crystallization of, 353. 

, effects of pressure on, 405, 409. 
, experiments on, 346. 

, friability of, 333. 

, liquefaction of, 353, 408. 

, liquid flowers in, 354-358, 424. 

, Thomson's theory of plasticity 
of, 340. 

, softening of, 333. 

, structure of, 136, 148. 

, temperature of, 241, 332. 

, white, seams of, 56, 413, 421. 

Illumination of trees, &c., at sun- 
rise and sunset, 178, 238. 

Interference rings, 229. 

spectra, 76, 178, 235, 238. 
Iridescent clouds, 100, 105, 147, 

J54, 238. 



MONTE ROSA. 

Jardin, the, 61, 174. 
Joch, the passage of a, 28. 
Joule, M., on heat and work, 328. 
Jungfrau, the, 11. 
, evening near, 106. 

Laminated structure, 376, 378, 

426. 
Lechaud, glacier de, 53, 387. 

, motion of, 60, 286-288. 
Lenticular structure, 381. 
Light and heat, 223, 239, 241. 
, undulation theory of, 224. 
Linth, M. Escher de la, 271. 
Liquefaction of ice, 353, 408. 
Liquid flowers, 147, 354-358, 424. 

Magnetic force, 144. 

Magnetism of rocks, 140, 143, 145. 

Marjelen See, 101, 119. 

Mastic, Briicke's solution of, 259. 

Mattmark See, 162. 

Maximum motion, locus of point 
of, 285, 323. 

Mayen wand, summit of, 20, 100, 323. 

Mayer, on connexion of heat with 
work, 328. 

Measurement of glaciers, 276. 

Mer de Glace, 42-67, 86-90, 173. 

, dirt-bands of the, 367 

(seen from Charmoz , 
45, 368; from Cleft 
station, 47, 369 ; from 
the Flegere, 367). 

, map of, 53, 264. 

, motion of, 275-293. 
, winter motion of, 294, 
343. 

, winter visit to, 195, 206- 

218. 

Milk, cause of blueness of, 261. 

Mirage, 36. 

Montanvert, 40, 89, 173. 

in winter, 204. 

Mont Blanc, first ascent of, 68. 

, second ascent of, 177. 
, summit of, 81, 189. 

Monte Kosa, first ascent of, 122. 

, second ascent of, 151. 

, summit of, 128, 156. 

, western glacier of, 138, 147. 

, zones of colour, 154, 238. 



444 



INDEX. 



MORAINES. 

Moraines, 263. 

- of Talefre, 54, 63, 267, 387. 
Motion of glaciers, 52, 269-295, 

422. 

Moulins, 362, 424. 
, depth of, 365. 
, motion of, 364. 

Necker, letter from, 178. 
Neufchatelois, Hotel des, 19, 112, 

270. 
Nev< ice, 249, 251. 

Oberland, the, visited, 9-22; 92- 

120 ; 390. 
Oils, effect of films of, 236. 

Person, M., on softening of ice, 333. 
Pistol fired on summit of Mont 

Blanc, 82, 83, 224. 
Pitch of musical sounds, 225. 
Planes of freezing, 163, 358, 424. 
Plasticity of ice, Thomson's theory 

of, 340. 

Polar forces, 4. 
Pressure and cleavage,'see Cleavage. 

and liquefaction of ice, 340, 408. 
veined structure, 404 ; 147- 

149, 382-394, 412, 425-426. 
, effects of, on boiling point, 408. 
ice, 405, 409. 

theory of glacier motion, 346. 

Eadiant heat, 105, 239. 
Eays, calorific, 240. 

-- transmission of, 242. 
Redness of sunset, 175. 
Refraction on lake of Geneva, 35. 
Regelation, 347, 351. 
Reichenbach fall, 17. 
Rendu, comparison of glacier to 

river, 306. 

, measurements of glaciers, 304. 
, notice of regelation, 301. 

on conversion of snow into ice, 

301. 

- on ductility, 298. 

on law of circulation, 300. 

on motion of glaciers, 305. 

on veined structure, 301. 

theory of glaciers, 299. 
Rhone at lake of Geneva, 34, 261. 



STELVIO. 

Rhone glacier, 20, 100, 323, 386. 
, chromatic effects, 21, 238. 
Ridges on glaciers, 42, 55. 
Riffelhorn, the, 133, 141-145. 
Rings, interference, 229. 

round sun, 21, 238. 
Ripples deduced from rings, 400. 
Ripple theory, Forbes on, 398. 

of veined structure, 398 

waves, movement of, 232. 
River and glacier, analogies be- 
tween, 281-285, 423 ; 368. 

Rocks, magnetism of , 140, 143, 145. 

Saas, avalanche at, 164. 

Sabine, Gen., on veined structure, 

378. 

Sand-cones, 266. 
Saussure's theory of glacier motion, 

52, 296. 
Scheuchzer's theory of glacier 

motion, 296. 
Seams, white, in ice, 56, 88, 413, 

421. 
Sedgwick, Prof., on cleavage, 2-5, 

390, 431. 
Seracs, 51, 75. 
Serpentine, boulders of, 161. 
Shadows, coloured, 38. 
Sharpe, on slaty cleavage, 5, 432. 
Silberhorn, the, 11. 
Sky, blueness of, 22, 174, 175. 
, colours of, explained, 257. 
Slate, cleavage of, 1, 430. 
Snow, blue colour of, 29, 132, 203. 

crystals, 130, 205, 212. 
, dry, 250. 

line, 29, 248. 
, perpetual, 248. 

, sound of breaking, 202. 
storm, sound through, 215. 
, whiteness of, explained, 250. 
Sorby, Mr., on slaty cleavage, 5, 

435. 

Sound in a vacuum, 224. 
, intensity of, 83. 
, rate of motion of, 226. 
Spectra, interference, 76, 178, 235, 

238, 

Spectrum, rays of, 240. 
Stars, twinkling of, 72, 238. 
Stelvio, pass of, 29. 



INDEX. 



445 



Storm on Grands Mulets, 185. 

Mer de Glace, 210. 
Strahleck, glacier of, 94, 384. 
- passage of, 93, 97. 

Strata of ice, 136. 
Stratification of neve*, 392. 

slate, 1, 430. 

Structure, doubts regarding, 44, 
92, 389. 

of ice, 136, 148, see Veined 
structure. 

Subjective colours, 37. 
Summary of glacier theory, 422. 
Sun, rings round, 21, 238. 
Sunrise at Chamouni, 39. 

and sunset, illumination of 

trees, &c., at, 178, 238. 
Sunset, gorgeous, 184. 

Tables, glacier, 44, 265-266. 
Tacul, motion of ice-wall at, 289. 
Talefre, glacier of, 43, 61-62, 87. 
, moraines of, 54, 63, 267, 387. 
Temperature, winter, of Alps, 168. 
Theodolite, use of, 275. 
Theory of cleavage, 5. 
Thermometer at Jardin, 174. 

buried on Mont Blanc, 190. 

on Finsteraarhorn, 113. 
Thomson, Prof., theory of plasticity, 

340. 

regelation, 352. 

Twinkling of stars, 72, 238. 
Tyrol, the, 23. 

Undulation theory of light, 224. 



YOUNG. 

Unteraar, glacier of, 18, 265, 388. 

Vacuum in ice-cavities, 163, 356. 

Veined structure, 376 (marginal, 
383 ; transverse, 384 ; longitudi- 
nal, 387), 395, 404, 408. 
, experiments on, 382, 388. 

caused by pressure, 147-149, 

382-389, 412, 425-426. 

crossing strata, 389-394. 
, Forbes on, 379. 

, Gen. Sabine on, 378. 
- , M. Guyot on, 378. 

, ripple theory of, 398. 
Viesch, glacier of, 109, 118. 
Viscosity, 312, 325, 334, 350, 423. 

Water absorbs red rays, 254. 

, blue colour of, 254; 33, 259, 

261. 

, rippling waves of, 232. 
Waves, frozen, 43, 55. 
, interference of, 231. 

motion, Weber on, 232, 399. 

of sound, 225. 
Wengern Alp, 9. 
Wetterhorn, echoes of, 15. 
White ice, seams of, 56, 57, 88, 

413, 421. 

Whiteness of ice, 250, 268, 376. 
Winter motion of Mer de Glace, 

294. 
Wrinkles on glacier, 370. 

Young, Thomas, theory of light, 
224. 



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