[LIBRARY I
UNIVERSITY OF I
CALIFORNIA
SAN DIEGO J
WATER
ITS ORIGIN AND USE
WAT E R
ITS ORIGIN AND USE
BY
WILLIAM COLES-FINCH
RESIDENT ENGINEER TO THE BROMPTON, CHATHAM, GILLINGHAM, AND
ROCHESTER WATER COMPANY, KENT
Illustrations of Mountain and Glacier Scenery
from the original pictures of
MRS AUBREY LE BLOND
(MRS MAIN)
"The lapse of time which is herein indicated, fills the mind
of man with awe ; but nature has no need to consider time ;
has she not eternity to work in?"- LORD AVEBURY.
LONDON: ALSTON RIVERS, LTD.
BROOKE STREET, HOLBORN BARS, E.G.
1908
PREFACE
BEING professionally interested in the finding and distri-
bution of water, as engineer to an important waterworks,
I have naturally been led to give this subject some atten-
tion and study, and I have derived no little pleasure in
gathering together into the present volume the notes and
memoranda which I have accumulated during a number
of years, in the hope that my readers may find in it some
matter of interest, and may be led to, the contemplation
of the wonders of nature.
Water in its various forms has been dealt with by
some of the most eminent of scientists.
The subject, like the boundless ocean, is so wide, that
there are few branches of scientific research in which it
does not claim attention.
This book, however, does not pretend to be a scientific
record ; it is simply an ordinary person's interpretation of
what he sees in nature, and represents his best efforts to
describe the same.
Of such sources of information as were at my disposal,
I have made free use : originality on such a theme was not
contemplated, nor is it possible.
It is a truism that we know least about the common
things we see and use every day of our lives. There are
vi PREFACE
writers on such subjects who have the happy gift of
imparting useful information in a pleasant and agreeable
way. In such company I have added to my slender
store of knowledge of the marvels of nature, and have
derived from their works much profitable amusement ; so I
set out to write down in simple language, and in proper
sequence, the results of my recreative studies and personal
experiences.
That others may be encouraged to a greater curiosity
about such things, and find therein both greater interest
and reverence for the Great Author of all, is the purpose
of this story.
With this special object in view, I have freely intro-
duced verses bearing upon the various subjects ; and I hope
that these may help to awaken the interest of those who
are not generally attracted to such subjects as this work
treats of, and in this manner may make the scientific facts
mentioned appear in a more acceptable form, for poetry
and nature are ever closely allied.
Many of the scientific facts mentioned in this book are
recorded in various works of note, but they have never
before been brought together in this manner.
Where I have quoted verbatim from any writer, I have
endeavoured faithfully to mention the fact. Should I
have omitted to do this in any instance, I trust that the
author will generously regard it as an oversight, and accept
this as my apology.
In making this request I am but copying one of the
minor poets of the last century, Peter Coxe, who in 1825
brought out a poem which he had "strengthened" con-
PREFACE vii
siderably by quotations from poets greater than himself.
" Distinguishing," says Joseph Bennet, " the larger extracts
in the usual way, he left the smaller to the unaided
perceptiveness of his subscribers ; but, fearing the critics,
he indited an apology, which concluded :
" ' When we with proper caution weigh,
And stealing, meditate our prey ;
And this we state lest any look
For plagiary to spurn the book,
And cautious mention at the starting
To bar all quarrel at the parting.' "
I wish to express my thanks to Mrs Aubrey Le Blond
for the beautiful Alpine illustrations which adorn this
volume, and to my friend Mr R. Keith Johnston for the
help he has given me in revising the manuscript and in
seeing my book through the Press ; also to Mr George F.
Deacon, for his kind assistance in connection with the
illustrations of the Vyrnwy Dam.
Should those who read my book derive as much pleasure
and profit from its perusal as I have found in its compila-
tion, the time and labour given to it will find sufficient
compensation, and I shall be amply rewarded.
W. COLES-FINCH.
WATERWORKS HOUSE,
LUTON, CHATHAM, KENT,
June 1908.
CONTENTS
CHAPTER I
HEAT
PAGE
In the Beginning ...... 1
Solar Heat ....... 8
Solar Constant of Heat . . . . . .13
Distribution of Heat . . . . . .15
Effect of Heat on Land, etc. . . . . .16
Thermal Unit of Heat . . . . . .17
Heat of Combustion of Various Fuels . . . .18
Temperature . . . . . . .18
Earth's Internal Heat ...... 20
CHAPTER II
ATMOSPHERE
Atmosphere ....... 24
Atmosphere, Composition of . . . .27
Atmosphere, Analysis of ..... 29
Specific Gravity of Elastic Fluids . . . .29
Carbonic Acid in Atmosphere ..... 30
Evaporation ....... 31
Vapour ........ 35
Vapour, Weight of . . . . .36
Saturation of Air ...... 38
Condensation of Vapour ..... 39
Vapour and its Effects ...... 39
Temperature of Atmosphere ..... 42
Compression of Atmosphere ..... 46
Expansion of Air ...... 48
Height of Atmosphere . . . . . . , 50
Height Penetrated ...... 51
CONTENTS
PAGE
, . 53
Pressure of Atmosphere
Contamination and Purification of Atmosphere
Velocity and Impulse . 63
Stellar Space
CHAPTER III
CLOUDS
66
Clouds . gg
How Formed . 6g
Cloud-banner . g g
Moisture in Clouds gg
Re-evaporation . -j
Dew-point . ^1
Forms of Clouds 72
Altitude and Velocity . 7&
Colour of Clouds
Dust Particles in Clouds
CHAPTER IV
RAIN
78
Cause of Ram . gl
Time of Greatest Fall . g2
Absorption and Percolation, etc.
Amount of Rain . g5
Distribution of Rain . gg
Extremes of Rainfall in 1905 .
Tropical Rainfall . ^
Rainless Districts gl
Impurity of Rain g2
Hardness of Rain-water gg
Dust Particles in Rain-water .
Rain-prints ' 95
Influence of Trees on Rain . ^
Signs of Rain . .
CHAPTER V
WATER
. 108
Water . 108
The Composition of Water 112
Molecules of Water
CONTENTS xi
PAOK
Specific Gravity of Water . . . . .113
Evaporation .... 116
Steam .... 117
Latent Heat of Steam ...... 120
Latent Heat of Water .... . 121
Specific Heat of Water . . . . . .122
Maximum Density of Water . 124
Congelation of Water ... 124
Cause of Expansion ... 125
Compression of Water . 125
Temperature and Pressure . . . . .126
Matter in Suspension . 126
Hardness of Water . . .127
Hardness and its Influence on Health . . . .128
Precipitation of Lime by Boiling . . . .130
Clark's Method of Softening . ... 131
Analysis of Chalk Water . .132
Analysis of Soft Water .... .132
Sea- water, Analysis of . . . . .133
Water in Articles of Food . . 136
The Aquarium ..... . 136
CHAPTER VI
FORMS OF WATER, Etc.
Dew 141
Hoar-frost ... 146
Sleet ........ 146
Hail ..... 147
Fog or Mist ... 148
Lightning and Storms .... .151
Waterspouts .... 154
Rainbows .... 155
Halos, etc. ... 156
Aurora Borealis ..... 157
Stalactites and Stalagmites . . 159
Stalactite Cave .... 160
..... 166
CHAPTER VII
SNOW
Snow
172
How Snow is Formed ... 172
xii CONTENTS
PAGE
Snow Crystals ... ... 173
Transparency of Snow . . . . . .174
Snow as a Conductor . . . . . .176
Impurity of Snow . . . . . .177
Snow-line . . . . . . .179
Snowfields ....... 181
Avalanches . . . . . . .183
Floods 185
CHAPTER VIII
ICE
Ice . . . . . .186
How Formed ....... 186
Ice-flowers . . . . . . .188
Expansion and Pressure ..... 190
Heat given out by Freezing . . . . .191
Freezing of Lakes . . . . . .192
Freezing point of Sea- water . . . . .193
Ground, Bottom, or Anchor Ice . . . .194
Ice-fields . . . . . .195
Polar Expeditions ' . . . . .196
Icebergs . . . J . . . . 201
Ice-floes . . . . . . . 205
Ice-pack . .. . . . . . . 205
Sea Ice . . . . . . . 207
Icicles ........ 208
Ice Formed in Caves ...... 209
Extremes of Temperature (Arctic) . . . .210
CHAPTER IX
GLACIERS
Glaciers ........ 213
How Formed ....... 214
Rate of Travel ... . . . .215
Extent of Glaciers ...... 218
Tributary Glaciers . ... 220
Plasticity and Regelation . . . . .221
Moraines ....... 224
Erratic Blocks ....... 224
Sand-cones and Glacier-tables ..... 225
Crevasses, how Formed ..... 227
CONTENTS xni
PAGE
Moulins ........ 233
Ice-barriers ....... 234
Lakes formed by Glaciers ..... 235
Advance and Retreat of Glaciers .... 236
Glacial Period, the . . . . .237
CHAPTER X
SPRINGS
Springs ........ 244
Surface Springs ....... 245
Deep-seated Springs ...... 246
Fault Springs . . . . . . . 250
Submarine Springs . . . . . .251
Capillary Attraction ...... 254
Line of Saturation ...... 255
Intermittent Springs ...... 255
Effect of a Drought on Springs ..... 256
Influence of Rain on Springs ..... 257
Infiltration and Pollution ..... 259
Geysers ........ 261
Water as a Solvent ...... 264
Thermal or Hot Springs ..... 265
Thermal and Mineral Waters , 268
CHAPTER XI
RIVERS
Rivers ........ 275
Length ........ 278
Velocity ........ 279
Solid Matter in Suspension ..... 281
Matter in Solution ...... 283
Recession of Waterfalls ...... 284
Deltas, etc., formed by . . . . . . 285
CHAPTER XII
WATERFALLS
How Formed ....... 290
Victoria Falls 290
XIV
Niagara Falls
Great Kaieteur Fall
CONTENTS
I'AGE
295
296
CHAPTER XIII
LAKES
Lakes
Crater Lakes, etc.
Surface Level of
Salt Lakes, how Formed
The Dead Sea .
Great Salt Lake, Utah, etc.
Dried-up Lakes .
Area of Lakes
Temperature of Lakes .
Colour of Lakes . .
301
304
305
305
307
310
311
312
313
Ocean and Sea .
Area
Depth .
Pressure and Depth
Temperature
Colour .
Power of Waves
Ocean Currents .
The Gulf Stream
The Polar Stream
Harvests of the Sea
Marine Caves
CHAPTER XIV
OCEAN AND SEA
314
317
317
320
322
326
328
333
335
337
339
340
CHAPTER XV
MOUNTAINS AND VOLCANOES
Mountains
Erosion and Denudation
Altitude of Mountains .
344
348
348
CONTENTS xv
I'AQK
Influence of, on Rain ...... 348
Volcanic Mountains ...... 349
Volcanic Eruptions ...... 352
Earthquakes ..... 357
Volcanic Islands . . 359
CHAPTER XVI
CHALK
Chalk .... 361
Thickness of . . , . 3g4
Flint and Gravel in . . . . p 354
Disintegration ..... 365
Chalk as a Natural Filter-bed ..... 366
Specific Gravity of, and Water contained in . . , 367
Natural Chambers .... 368
Percolation in ..... 371
Adits in . . . . . . 371
Description of Adits . . 372
CHAPTER XVII
DENUDATION
The Forces at Work .... 375
By Change of Temperature ... . 377
By Chemical Action . . . . 377
By the Atmosphere . . 377
By Rain ...... .378
By Rivers and Streams ... 381
The Weald of Kent . . 381
The Isle of Wight . 383
The English Channel . 333
Animal Remains . . . 334
By Landslips .... 335
By Glaciers . . 3g5
Formation of Plains, etc. . . 387
River Terraces . . . 337
By the Sea ... 388
By Tides .... 391
xvi CONTENTS
PAGE
CHAPTER XVIII
WATER, HOW OBTAINED
Shallow Wells ....... 396
Deep Wells ....... 398
Adits ........ 401
Horizontal Wells and Upward Borings . . . 404
Cause of Accidents in Wells ..... 404
Artesian Wells ..... .406
The Passy and other Borings ..... 409
Borings in the Medway Valley . . . .413
Rest-level and Area of Exhaustion . . . .416
Water from Lakes and Rivers . . . . .419
Water from the Elan Valley, from Lake Vyrnwy, etc. . 420
Aqueducts ....... 424
The Coolgardie Water Supply . . . . .426
Reservoir Dams ...... 429
Filtration ....... 431
Covered Reservoirs ...... 432
Artificial Distribution of Water . . . . 435
CHAPTER XIX
USE, ABUSE, AND WASTE
The Work of Water ...... 437
Irrigation ..... . 438
The Nile and the Assuan Dam . . . .441
The Temple of Philae ...... 444
Canals ........ 446
Power of Falling Water ..... 448
Hydraulic Cranes, etc. ...... 455
Sports and Pastimes ...... 458
Waste of Water ....... 460
Waste of Water by Frost ... .461
Lavish Use or Abuse .... . 464
Domestic Waste . . . . . . .464
CHAPTER XX
LESSONS FROM NATURE 466
LIST OF ILLUSTRATIONS
The Inn Kiver, near St Moritz early Morning . Frontispiece
FACING PAGE
A Trilobite ....... 2
The Nebula in Andromeda ..... 2
A Piece of Chalk, magnified . . . . .12
To illustrate the Immensity of the Sun . . .12
Snow (not Cloud) blown from a Mountain Summit, Engadine 32
Typical Natural Waterworks ..... 38
Twilight (from Young's Astronomy) . ... 40
Atmospheric Kefraction (Dr Mill) . . . .40
Diagram of Area covered by Sun's Kays . . .44
Diagram of Thickness of Atmosphere traversed by Sun's Rays 44
The Cloud -banner of the Matter horn . . . .68
Sea of Cloud over the Lake of St Moritz while freezing . 70
A Cloud Study, Engadine . ... 70
Above a Sea of Cloud, Arctic Norway . . . .72
Clouds breaking like a Giant Waterfall over the Furggen
Ridge, Matterhorn ...... 72
H.M.S. Phcenix driven ashore off Kowloon . . .74
Wrecked by the Typhoon, Kowloon . . . .74
The Matterhorn, from the Zmutt side . ... 80
Prehistoric Rain-prints on a Slab of Sandstone . . 94
Portion of the same Slab . . . . .94
Hoar-frost on a Tree . . . . . .146
A Network of Pearls (fog precipitated on a spider's web) . 148
Mountain Mists ....... 148
On the Matterhorn the way blocked by Mist . . .152
Above the Fog and Mist, 12,000 feet above sea . .152
The Alps from Belalp after a Storm . . . .154
Caverns of Han, Salle d'Embarquement . . .164
Snow Crystals . . . . . . .172
Crystallized Snow . . . . . .174
A Study of Snow in detail, taken at St Moritz . .174
xviii LIST OF ILLUSTRATIONS
FACING PAGE
12,000 Feet above the Sea . . . . .178
Off towards the Matterhorn . . . . .178
A Corniced Ridge on an Engadine Peak . . .178
Snowfields from Piz Palii, Engadine .... 180
Crossing a Snow Bridge over a Crevaase (Sella Pass) . .182
The Remains of an Avalanche . . . . .184
A Train stuck fast in an Avalanche on Rocher de Naye . 184
An Avalanche blocking a Stream . . . .186
A Tunnel 300 feet long cut through an Avalanche . .186
An Avalanche Gully in Arctic Norway . . .188
An Ice-cave in the Morteratsch Glacier . . .188
Ice-flowers in the Alps . . . . . .190
The same spot twenty-four hours later . . . .192
The Ice-flowers at Close Quarters . . . .194
Detail of Petals of the Ice-flowers . . . .196
The Ice-flowers meet with an Untimely End . . .196
A Summer River of Ice . . . . .210
A Distorted and Crevassed Glacier (the Morteratsch) . . 214
Reflections on Glacier Lake, Arctic Norway . . .218
Glacier, Arctic Norway . . . . . .218
Tributary Glaciers ...... 220
Near Top of Monte Rosa, Tributary Glaciers and Moraines
joining . . . . . . 222
The Monte Rosa Group from Wellenkuppe Glacier passing
through a Narrow Gorge ..... 222
Rothhorn from near Unter Gabelhorn, showing the Moraine . 224
The Gb'rner Glacier and Moraine .... 226
A Glacier Table, Morteratsch Glacier .... 226
A Big Crevasse on a Snow-covered Glacier . . . 228
Ice-fall, Pers Glacier . . . . . .230
An Erratic in the Form of a Glacier-table, with Sand-cone . 230
Mont Blanc ....... 232
The Overhanging Cornice of Snow a frequent source of
accidents ....... 232
An Active Moulin or Glacier Mill .... 234
A Shatter of Boulders, Arctic Norway .... 236
Glacier Lake, with Polished and Striated Rocks, Arctic
Norway ....... 236
One of the Mammoth Tusks found in the Dry Chalk Valleys . 240
Sketch showing Curve and Sections .... 240
A Typical Surface Spring, Hollingbourne, Kent, issuing from
the face of the North Downs .... 244
Plan showing the Dry Chalk Valleys, North Downs . . 246
LIST OF ILLUSTRATIONS xix
FACING PAGE
Section of Wells of Dry Chalk Valleys . . .248
The Origin of Springs (after Prestwich) . . . 252
Section to illustrate Intermittent Spring . . . 252
Diagram showing how a Fault may cause a Submarine Spring
to be formed ...... 252
Geological Section, showing the different kinds of Wells and
Springs, etc. ...... 254
Diagram showing the Effect of a Succession of Dry Years
(1895-1902) ...... 256
A Deep-seated Spring in the Dry Chalk Valleys of the North
Downs ....... 260
The Pink and White Terraces and Springs of Rotomahana,
New Zealand ...... 266
Ice-cave formed in the Snout of the Loen Glacier by the
Glacier Stream ...... 276
A Nearer View, showing Stream issuing from the Ice-tunnel . 276
The Natural Bridge and Gorge, Constantine, cut out by Water 280
A Beautiful Norwegian Waterfall near Trondhjem . . 282
To illustrate the Recession of Niagara .... 284
Section showing the Rocks at the Falls of Niagara . . 284
Niagara in Winter ...... 290
The Horseshoe Fall, Niagara . . . . . 292
The Gorge, Niagara ...... 292
The Zambesi Gorge ...... 294
The Swallow Falls, Bettws-y-Coed, North Wales . . 296
Waterfall, Ragaz, on the Road to Pfaffers, Switzerland . 298
A Lake on the Gorner Glacier between the Ice and the Moraine 300
A Glacier Lake formed by a Moraine, Artie Norway . . 300
The Lake of Geneva ...... 304
A Typical Mountain Lake . . . . .312
Typical Rough Sea and Coast Scene . . . .328
Coast Erosion at Southwold, Suffolk . . . 330
The same spot two days later ..... 330
Vegetation in Norway, 200 miles within the Arctic Circle . 336
Ice-lake in Arctic Norway, 2000 feet above the sea . . 336
The Azure Cave, Capri, Italy ..... 340
Hardanger Fjord, Norway ..... 342
Sor Fjord, Norway ...... 342
The Matterhorn from the Zinal Ridge of the Rothhorn . 344
Monte Rosa ....... 346
A Hanging Glacier on Ober Gabelhorn . . . 348
A Mountain Summit, Piz Bernina .... 348
Strood Waterworks Natural Chamber and Adit in the Chalk 368
XX
FACING PARE
The Natural Chamber, Strood . . . . .370
The Natural Adit, Strood . . . . .370
An Artificial Adit in the Chalk Formation, with Branches
running in all directions to intercept the Water-bearing
Fissures ....... 372
At the Bottom of the Well (the Bucket ascending with the
Excavated Chalk) ...... 374
A Gendarme near the Ortler ..... 378
Section of the Weald of Kent ..... 380
Old Well-head, Snodhurst Farm, Kent . . .380
A Mountain Stream . . . . . . 382
The Bietschhorn ...... 386
The Birthplace of Glaciers view from Monte Rosa . . 388
Sections of a Deep Well ..... 398
Men and Tools employed on the Artesian Boring, Luton,
Chatham ....... 400
The Author and Men boring with a 60-inch Chisel . . 400
An Artificial Adit in the Chalk . . . .402
An Artificial Adit in the Chalk Formation . . . 404
The Author's Method of controlling Underground Water
during Extension of Adits . . . . 406
Diagram showing Adit driven into the Escarpment of the
North Downs, Folkestone . . . . 408
Geological Section through the Paris Basin . . . 408
A Typical Artesian Boring . . . . .410
Exploding a Cartridge in a Deep Boring to increase the Yield
of Water . . . . . . . 412
Geological Section illustrating how Water is obtained from
both the Upper and Lower Cretaceous Formations at
Chatham . . '.".". . 414
Enlarged Section of the Artesian Boring, Luton, Chatham . 416
Geological Section through the London Basin . . .418
The Vyrnwy Dam excavating the Trench across the River
Vyrnwy ....... 420
The Vyrnwy Dam nearing completion . . . 422
Roman Aqueduct at Segovia, Spain .... 424
An enlarged portion of the same .... 424
Ruins of a Roman Aqueduct at Merida, Spain . . 426
Puente del Diablo, Tarragona, Spain .... 426
A Roman Aqueduct, Pont du Gard .... 428
The Water Channel, Pont du Gard . . . .428
A Covered Service Reservoir, 5,000,000 galls, capacity, in
Course of Construction . . 432
LIST OF ILLUSTRATIONS xxi
FACING PAGE
The Iron Columns and Girders that support the Roof, with the
Centering to form the Arches .... 432
The Assuan Dam across the Valley of the Nile . . 442
The Great Colgate Power House in the Sierra Nevada
Mountains ....... 452
In a Cool Corner of my Garden .... 454
The Author measuring the Rainfall .... 454
The Cascades and Fountains of the Royal Palace of Caserta . 456
The Bath of Venus ...... 456
Skating . . . . . . .458
Tobogganing, Davos Platz ..... 460
Diagram from Electrical Water-Level Recording Apparatus . 462
The Valley of Celerina from St Moritz . . .468
Ice-ferns on Window Pane ..... 470
Portion of above photographed natural size . . . 470
An Erratic Boulder, Zermatt ..... 472
An Erratic Boulder with Osprey's Nest on Top . . 472
The Frozen River Medway, 16th February 1895 . . 476
WATER
ITS ORIGIN AND USE
CHAPTEK I
HEAT
In the Beginning
" Before the hills in order stood,
Or earth received her frame."
To trace the story of water and its work we must go back
to the very beginning of the earth's history.
The word " beginning " is not intended to carry the
mind of the reader back to that period at which it
pleased God to create and disperse into space the marvel-
lous elements of the material world, the Biblical descrip-
tion of which is so familiar to us, and no verse of the
Scriptures is more pregnant with mystery than the first :
"In the beginning God created the heavens and the
earth." This is not true, says Dr Harley, because it is
found in the Bible, but it is found in the Bible because it
is true.
According to Euskin, " there are, broadly, three great
demonstrable periods of the earth's history. That in
which it was crystallized, that in which it was sculptured,
and that in which it is now being unsculptured or deformed.
2 WATER: ITS ORIGIN AND USE
These three periods interlace with each other as the
periods of human life do ; of their length we know as yet
nothing, except that it has been greater than any man has
imagined."
It will therefore be well to commence our story from
the period of its crystallization, the study of which will
unlock the past history of our planet, and, as Hugh
Miller says, " will acquaint us with God's doings upon it,
as the Creator of all, for myriads of ages ere He had first
breathed the spirit of life into human nostrils, or man had
become a living soul."
This part of the Creator's work preceded all the divine
accounts of the Creation which we read in the book of
Genesis; it is also beyond the comprehension of the
greatest astronomers and geologists that have ever lived.
Of this period Dr Buckland writes: "It is nowhere
affirmed that God created the heaven and the earth in the
first day, but in the beginning. This beginning may have
been an epoch at an unmeasured distance, followed by
periods of undefined duration, during which all the
physical operations disclosed by geology were going on."
The evolution of our solar system from the original
elements, as generally understood from the nebular theory
of the renowned Laplace, is, as far as man is concerned, all
we know of the beginning. But this is only a hypothetical
theory, "it cannot be demonstrated by observation or
established by mathematical calculation, but, from the
study of other systems, astronomers have generally
regarded this theory with considerable approval."
According to Sir Norman Lockyer, a nebula consists of
vast swarms of meteorites moving in different directions,
and dashing against each other with such force as to
generate sufficient heat to dissolve themselves into
luminous vapour.
THE NEBULA IN ANDROMEDA.
A TRILOBITE.
To face p. 2.
IN THE BEGINNING 3
This globe was, then, but a iiebula, or a mass of gaseous
matter, a fluid haze of light. The whole of our solar
system, in fact, was evolved out of this immense nebula,
which must have been thousands of millions of miles in
diameter, similar to many now adorning the heavens.
This rotating nebula, cooling by radiation of its heat
into space, contracted and condensed towards the centre,
leaving behind successive rings, in this manner giving
birth to the planets, of which our earth is one of the
smaller, and at last solidifying into and forming the sun
as we see it to-day.
Other astronomers, however, believe that the parent
nebula assumed a pear-shaped form, and that the smaller
end became detached, forming a planet with independent
existence, and, as was the case with our own planet in its
early days, self-luminous.
The mass of solid matter now forming the sun and all
the planets is said to represent only about one five-
thousandth part of the mass of the original nebula.
A study of this story will tell us how worlds like ours
were so marvellously formed, and are now in the process
of formation. Beginning with a state of gaseous vapour,
we pass next to one of a mass of liquid matter of intense
heat, and thence to the solidification of this molten mass.
Throughout the gaseous period the immense body of
matter surrounding the globe must have been millions of
miles in thickness, and during this period water was present
only in the form of vapour ; but, after a lapse of time, with
the solidification there came a cooling, the reduced
temperature was insufficient to maintain in a state of
vapour the vast amount of moisture in the atmosphere,
and the oxygen and hydrogen combined, giving birth to
the water which now forms the oceans, seas, lakes, and
rivers.
4 WATER : ITS ORIGIN AND USE
Whether water was existing in the atmosphere during
the molten period, in the form of rarefied steam, or as its
constituent gases, oxygen and hydrogen, in an uncombined
state, is unknown. It is certain that no water could have
rested on this molten surface, the temperature of which
must have been at least 10,000 F., a degree of heat almost
beyond our comprehension, but one which we dare not
question, for Sir William Crooks tells us that in the
manufacture of diamonds it is necessary to raise the
temperature of the electric furnace to 7200 F.
According to Professor Sollas, liquid water (or, as I have
seen it called, " wet water ") could not have begun to
accumulate until the surface of the earth had cooled to
716 F. When it had cooled sufficiently, the water
condensed and remained upon the earth, covering the
whole surface.
Owing to the heat of the earth, the evaporation and
condensation were enormous. Rain fell upon the earth :
but it was not cool, refreshing rain, with which we are
familiar. It was a deluge of boiling water, described by
one eminent scientist as red-hot rain, with a ceaseless
accompaniment of thunder, lightning, and steam. How
long this fierce battle between fire and water continued,
we cannot say. Probably hundreds of thousands of
years elapsed before the contest ended in water being
victorious.
It is certain that at this period there was a total absence
of organic life upon the earth. None of the forms of life
with which we are acquainted, or the remains of which
have from time to time been discovered, could have existed
in or survived the intense heat of this period.
Many millions of years must have passed before the
Creator of the universe saw fit to provide even the most
primary form of organic life, and innumerable forms of
IN THE BEGINNING 5
both animal and vegetable life had existed and passed
away into geological history before it was deemed a fitting
habitation for man.
The preparation of the globe for all forms of life was
impossible without water ; thus in these remote ages
water had commenced its useful and necessary work a
work, we shall see, it has never ceased to perform.
" Of all physical agents," says Dr Buckland, " that have
at any time and in any manner affected the surface and
interior of the earth, in the foremost rank we find fire and
water those two universal and mighty antagonistic forces,
which have most materially influenced the condition of
the globe, and which man has also converted into most
efficient instruments of his power."
"During the earlier ages of our globe," says Louis
Figuier, " waters covered a great part of its surface, and
it is in them that we find the first appearance of life.
When the waters had become sufficiently cool to allow the
existence of organised beings, creation was developed and
advanced with great energy, for it manifested itself by
the appearance of numerous and very different species of
animals and plants."
The crust of the earth is variously stated to be 30 or
40 miles thick, under which is a layer of molten matter
60 to 100 miles thick, the whole centre of the earth being
gas, but under such pressure and of such great density as
to be three times heavier than granite and as incom-
pressible as steel.
Further research, however, into the question of the
thickness of the earth's crust has caused a much higher
figure than the above to be stated. It is assumed that a
thickness of at least 2000 to 2500 miles would be neces-
sary to enable the earth to maintain its shape, the tide-
producing force exerted by the sun and moon on our globe
6 WATER: ITS ORIGIN AND USE
being sufficient to cause a deviation from its present shape,
were it only, say, 100 miles thick.
With the consolidation and buckling of the earth's
surface, mountains were thrust up from the deeps, and
vast continents began to appear above the heated waste
of the waters, and it is apparent that
"Then began the gathering together of the waters
called seas, and the dry land appeared."
The struggle for the mastery between fire and water
continued intermittently ; for the earth was still passing
through great convulsive changes, accompanied by earth-
quakes and eruptions of internal fires, the crust of the
earth gradually thickening. During these eruptions meta-
morphic rocks and mountains were in process of formation.
In all this water played, as we have seen, an important
part, and practically "laid the foundation of the earth,
that it never should move at any time."
" We have traced back," says Dr Buckland, " the history
of the primary rocks, which composed the first solid
materials of the globe, to a probable condition of universal
fusion incompatible with the existence of any forms of
organic life, and have seen reason to conclude that, as the
crust of the globe became gradually reduced in temperature,
the unstratified crystalline rocks and stratified rocks pro-
duced by their destruction were disposed and modified,
during long periods of time, by physical forces, the same in
kind with those which actually subsist, but more intense in
their degree of operation ; and that the result has been to
adapt our planet to become the receptacle of divers races
of vegetable and animal beings, and finally to render it a
fit and convenient habitation for mankind."
Probably neither the greatest geographical or geological
scholar, nor even the greatest living astronomer, is suffi-
ciently acquainted with the universe, or the structure of
IN THE BEGINNING 7
our earth, to speculate, without fear of contradiction, as to
its age, or the duration of any of its previous forms.
Eeferring to this subject, Sir Oliver Lodge remarks that
" he did not know why it had taken so long to produce
man upon the earth. That was a mystery of which he
could only speak with bated breath, but he supposed that
in a sense it could not be done any quicker with the same
completeness or thoroughness. In the early years of
existence the world contained only the lower forms of lifo,
but it gradually improved, until it became what it is, and
man attained his present state. But lower and higher
forms still exist on the planet."
Hugh Miller considers that the vast series of long
geologic ages and their successive creations, each placed in
advance of that which had gone before, are more worthy
of their Divine Author than had the whole work been
huddled into a few literal " days," " and thus convert the
incalculably ancient universe which we inhabit into a
hastily run-up erection of yesterday."
The story of the successive geological periods and the
gradual evolution of life, of the fossil remains of marine
vegetation, of fishes, insects, land vegetation and terrestrial
animals, is too vast a subject for further investigation
here, and we must leave them to the geologist and the
chemist, and proceed to the simpler wonders of creation,
in which the work of water can be more easily traced than
in the period just considered.
It is, however, more than probable that life first had its
being in these more or less heated waters ; and it is in
this respect that the waters of the globe have been con-
sidered by many to be the cradle of the world.
The first dawn of life is variously stated as having taken
place some forty or fifty million years ago. How this
first gerrn of life (or protoplasm), the structural unit and
8 WATER: ITS ORIGIN AND USE
basis of all organic bodies, came into being, and began its
vital and endless function of evolution, culminating in
man, none can tell.
We can only believe that this life must have had a
divine origin, or, as we term it, creation ; for it can only
be begotten of life, and reproduced only by living organ-
isms ; by no conceivable process could living matter arise
from dead matter; but we do know that rocks formed
of the sediment of the ancient seas have yielded the
fossil remains of some of the earliest forms of life, which
were of marine origin, but by no means the first life.
One of the creatures referred to is the trilobite, a
widely distributed family of extinct palaeozoic Crustacea,
comprising more than fifty genera, which are found in the
Cambrian and Silurian strata. They are so named from
their bodies being divided into three lobes. These little
creatures, which nature has preserved to us in fossil form,
are probably 12,000,000 years old, and represent a very
low form of life. Their marvellous construction will
well repay the reader for any time he may spend in
learning more of them.
Solar Heat
We have seen that, in the beginning, the atmosphere
was heated principally by the earth itself. Continuing
the history of our globe, there came a time when this heat
was, for purposes of evaporation, practically insufficient.
It has been ascertained that the amount of internal heat
now escaping from the earth each year would be only
sufficient to melt a shell of ice one-fifth of an inch thick
over the whole surface of the globe. The atmosphere,
therefore, found itself compelled to rely solely on the sun
for its warmth.
It will be necessary, therefore, for the purposes of this
9
story, to consider as concisely as possible heat and its
relation to water.
The heat of the sun is inseparable from any description
of water and its origin. The sun controls the solar system.
It is really the cause of water in all its forms. In short,
the whole of nature depends for its very existence upon
the energy imparted by the sun. It has been rightly
called " the grand prime mover in all that circulation of
matter which goes on, and has gone on for untold ages."
In following water, therefore, through its varied and
interesting phases, we must understand more fully the
source from which all this power and work originates.
The ancient inhabitants of our earth had a most erroneous
idea of these matters. "They believed," says Sir Oliver
Lodge, " that the earth was the centre of the universe, the
world to which everything else was an appendage, a world
with a sort of sky over it, in which there were lights which
regulated our seasons. What is the earth to us ? A
round globe, flying through space 19 miles every second
of time around the sun ; one of a family the solar
system ; smaller than most of the others, larger than
some. Spinning round the sun, that sun only one of a
myriad of smaller suns."
We cannot do better in connection with this than quote
the words of Sir Robert Ball : " To thoroughly obtain some
conception of the intensity of the heat of the sun, we
must imagine a temperature of molten steel, of such heat
that it will run like water. Multiply this by seven, and we
have then something approaching the fearful intensity of
the celestial furnace that we see in the heavens.
" The earth is a mighty globe, yet what are the dimen-
sions of our earth in comparison with those of the sun ?
If we represent the earth as a grain of mustard seed, then,
on the same scale, the sun should be represented by a
10 WATER: ITS ORIGIN AND USE
cocoanut. Again, look at the moon, which revolves round
the heavens at a distance from the earth of 244,000 miles ;
yet the sun is so large that if there were a hollow globe
equally great and the earth were placed in its centre, the
entire orbit of the moon would lie completely within it.
" The solar heat is scattered through space with bound-
less prodigality. The earth receives but an infinitesimal
fraction of what the sun emits. The heat and light daily
lavished by the sun would suffice to warm and illuminate
2,000,000,000 globes, each as great as the earth."
Thus the earth receives only ^.-(jfffroVTLSou part, and the
earth and the whole of the planets receive only s2T,<j^o,tffftf
part of the whole heat and light dispersed by the sun;
the rest is lost in interstellar space. Should the heat of
the sun's rays be utilized as a mechanical force, it has been
calculated that, on a bright summer's day, the heat is
equal to five thermal units per minute to each square foot of
surface, if placed so as to receive the rays perpendicularly.
A simpler comparison may perhaps help us to form an
idea of the immensity of the sun. The diameter of our
earth at the equator is 7926 miles; that of the sun is
866,000 miles. The mean distance of the earth from the
sun is 93,080,000 miles. Sir George Airy, from the transit
of Venus (1874), made it 93,300,000 miles. It may be
mentioned that its determination has been attempted in
four ways, with the following results :
Miles.
By parallax . . . Distance 92,908,000
velocity of light . 93,075,480
motions of the moon 92,958,000
mass of earth com-
pared with the sun 93,113,000
The mean distance of the earth from the sun in winter
is 93,950,000 miles; in summer, 90,950,000 miles. The
SOLAR HEAT 11
surface area of the earth would have to be multiplied by
11,946 to get the area of the sun's surface ; and the volume
of the sun is 1,252,700 times greater than our earth, and
its mass exceeds that of the earth 316,000 times, its mean
density being only one-fourth of the earth's.
That is to say, its weight is not in equal ratio, being
only equal to 316,000 earths, whereas, if its density were
the same as the earth's, it would equal 1,252,700 earths.
The sun's mass or weight, however, is also equal to 750
times the united masses of all the planets which gravitate
around it ; thus we see that what it lacks in weight it
makes up for in size, and by its attraction keeps the earth
and all the planets whirling round in space at their
respective distances, warming and lighting them through
" space " : a simple word, but conveying much ; for
Mercury, the planet nearest to the sun, is 35,393,000 miles
distant, while Neptune, the most distant, is 2,746,271,000
miles away !
Marvellous as these astounding figures are, Lord Kelvin
estimates that there are 1000 millions of such suns in the
heavens, each being the centre of a universe having
earths perhaps like ours.
In order to comprehend these immense distances, we
may express them by a simple arithmetical calculation.
Taking the diameter of the moon as 1, the earth would be
represented by 4, and the sun by 400, and 619,000 full
moons would be required to equal the light of the sun.
The enormous size of the sun seems to be hardly possible,
for when the moon comes between the sun and our earth,
its outline and the sun's surface seem to be about of equal
diameter ; the one appears just to cover the other, as one
would cover one coin by another of the same kind or
value. This equality is indeed only apparent ; the moon's
shadow covers that of a body four hundred times its size
12 WATER : ITS ORIGIN AND USE
because of the distance of the sun, which is about four
hundred times farther away from the moon than the latter
is distant from the earth. That the reader should really
grasp the magnitude of the sun is so essential to the follow-
ing of our story, that, at the risk of perhaps wearying him,
I would suggest that he should construct a model of simple
articles.
We will take the peel of half an ordinary orange, and
call this the sun (866,000 miles diameter). We next find
a small glass bead equal in diameter to, say, one-hundredth
of that of the orange ; we will call that the earth. Our
next difficulty will be to find a bead small enough in
diameter to equal one-fourth of that representing the
earth ; this minute article will represent the moon (2159
miles in diameter). Suspend these two beads on a piece
of cotton or wire across the centre of the orange-peel,
placing the larger bead (earth) in the centre ; the moon
revolves round our earth at a mean distance of 238,818
miles, or, roughly, about one-fourth of the diameter of
the sun.
Therefore, the smaller bead must be placed halfway
between the centre bead (earth) and the edge of the
orange-peel. We shall then see at a glance the relative
proportions of the sun and of this world on which we
live.
What do we not owe to the sun ?
Dr Fitchett says: "The white of the lily, the purple
of the violet, comes from the sun; the crimson of the
poppy was eight minutes ago actually in the sun,
93,000,000 miles distant.
" The waves of light smite the flower ; by some unknown
process of vital chemistry, the flower disintegrates the
ray, it selects and absorbs some colour-element, and reflects
others.
SOLAR CONSTANT OF HEAT 13
" The miracle goes on while we gaze, under our very eyes.
The tiny flower, it may be said, interprets the ultimate
elements of light to our consciousness."
Professor Tyndall also writes : " The purple colouring of
the mountains encountered on looking down the valley was
indescribable. Oxygen and nitrogen could not produce
the effect; some effluence from the earth, some foreign
constituent of the atmosphere, developed by the sun, must
sift the solar beams, abstracting a portion, and blending
their red and violet to that incomparable hue."
The temperature of the surface of the sun has not yet
been accurately ascertained. It is, however, agreed that
the temperature and radiation have remained constant for
a long period.
" Tradition holds this ball of fire,
Must burn for ever, nor expire."
How the sun's heat is sustained is not within the scope
of our story. Should the reader be sufficiently interested,
let him read The Uarth's Beginning, by Sir Kobert Ball,
where this most interesting subject is treated; but the
reader must not feel alarmed if he finds that the sun, in
order to send forth the grateful heat we so much appre-
ciate, is contracting, and is smaller in diameter by one mile
every twenty-five years. This diminution is practically
insignificant when compared with its enormous size.
Solar Constant of Heat
If we have thoroughly conceived, as far as human mind
can conceive, the size and mass of the sun, the next and
not less important task will be, to get a similar com-
parative idea of its heat, both at its surface and here on
our earth: the former that we may better be able to
account for its warmth reaching us, so far distant as we
14 WATER: ITS ORIGIN AND USE
are from it ; and the latter that we may better comprehend
some of the marvellous works it accomplishes here.
"The solar constant is the number of units of heat
which fall in one minute on one square foot of a surface
placed at right angles to the sun's rays, and situate at the
mean distance of the earth from the sun. We shall suppose
the loss due to atmospheric absorption is allowed for, so
that the result will express the number of units of heat
that would be received in one minute on a square foot
turned directly to the sun, at a distance of 93,000,000
miles. This amount has been found to be sufficient to
raise 1 Ib. of water 14 F. in one minute. The total
radiation from the sun must suffice to convey in each
minute, to a sphere whose radius is 93,000,000 miles, 14
units of heat per square foot of that surface. This radia-
tion comes from the surface of the sun. Now it is easily
shown that the heat from each square foot on the sun will
have to supply an area of 46,000 square feet at the distance
of the earth. Hence the number of units of heat emerg-
ing each minute from a square foot on the sun's surface
must be about 640,000, which in the course of a year would
be equivalent to the heat generated in the combustion of
11,000 tons of best coal " (Sir Eobert Ball).
The highest temperature with which we are acquainted
is said to be that of the " electric arc," viz. 3500 C.
It is calculated that all the coal on the earth would not
supply the sun's heat for one-tenth of a second, and that
this heat is maintained by the shrinking of the sun, its
particles developing heat by falling together. In this way
the amount of heat expended by the sun for the past
24,000,000 years can be accounted for.
It is also estimated that the sun's radiation would
melt a coating of ice, covering its own surface to a depth
of 40 feet, in one minute. To measure the sun's heat,
DISTRIBUTION OF HEAT 15
an ingenious instrument called the pyrheliometer is used,
this being the invention of M. Pouilett.
Lord Kelvin concludes that the amount of heat which
the earth radiates from its surface and loses would in
20,000 million years be sufficient to melt the entire bulk
of the earth, if the rate of loss had always been what it is
now, and the earth had consisted throughout of the same
materials as its surface rocks.
At times of a total eclipse of the sun, long coronal
streamers are seen ; these mighty tails of light shine with
an intrinsic light of their own, consisting, it is believed, of
hydrogen of such high temperature as to be self-luminous.
These streamers are of enormous length ; in the eclipse
of 1898 they were ascertained to be equal in length to six
times the diameter of the sun.
Distribution of Heat
The next interesting point of the study of our luminary
will naturally be the distribution of its genial warmth.
We are now concerned with a matter of which we really
have definite knowledge, each of us personally, without
having to lean quite so heavily on the scientists to whom
we owe so much.
Shakespeare says : " All the world is cheered by the
sun." In some parts of the earth he not only cheers, but
seems determined to make his presence rather uncomfort-
ably apparent.
The highest temperatures occur in India, North Africa,
Eed Sea, Persian Gulf, and Australia. In the centre of
the Sahara Desert, 130; New South Wales, 120. Paris
once recorded 106. London has seldom recorded more
than 96.
It is in these regions of extreme heat that the terrestrial
16 WATER: ITS ORIGIN AND USE
radiation is greatest, the cooling effect of which produces
nights of comparatively intense cold.
It is, of course, known to most readers that summer
occurs in the northern hemisphere when the earth is at
the greatest distance from the sun, and winter when it is
nearest to us. In the northern hemisphere the difference
is about 3,000,000 miles. Further reference will be made
to this subject in a future chapter.
It is curious also to note that from 31st May to 16th July
more heat falls on the North Pole than on any other part
of the earth. " This heat is mainly employed in melting
the Arctic ice and raising the temperature of the water,
and not in raising the atmospheric temperature, and so,
even in these cold regions, again equalising the tempera-
tures " (Archibald).
Effect of Heat on Land, etc.
If the same amount of sun-heat were to fall upon an
equal area of land and water, it would raise the tempera-
ture of the former four or five times as much as that of
the latter. The rays which fall on the land are absorbed by
the thin surface layer exposed to them ; the temperature of
the surface increases ; a wave of heat passes downwards
through the soil, the intensity of the wave varying with
the conductivity of the soil ; but it generally ceases to be
measurable at a depth of 4 feet. Part of the heat of
the surface layer is reflected upwards, heating the lower
stratum of air with which it comes in contact.
Rays falling on the water are not arrested at the surface,
but penetrate to a considerable depth. In clear water the
heat of the sun is perceptible at a depth of 500 to 600
feet. Therefore, the heat being diffused downwards, the
surface of the water is heated by day less than the surface
THERMAL UNIT OF HEAT 17
of the land, and, as will be apparent, it also cools less
during the night, by terrestrial radiation. This is the ex-
planation of the fact that the sea maintains a more uniform
temperature than the land. These differences in radiation
of heat from land and sea help in the general circulation
of the atmosphere.
The rays of the sun, in passing through the air, affect
the vapour particles 764 times more than the dry ones.
In passing through stellar space but little of the sun's heat
is lost.
Thermal Unit of Heat
The reader will probably wonder why he is asked to
consider the thermal unit of heat here ; but heat changes
the dimensions of all bodies. Increase of volume is the
normal effect, although the reverse is observed in water
between C. and 4 C. Without some short reference to
this matter, we cannot possibly grasp many of the interest-
ing phenomena to which we shall refer ; and the aim of the
writer is not only to state facts, but to enable the reader
to understand their causes.
The thermal unit of heat is the quantity of heat re-
quired to raise I Ib. of water 1 F. (from 60 to 61 F.),
utilising energy equivalent to that required for raising
772 Ibs. through 1 foot, or 1 Ib. through a height of
772 feet, called foot-lbs. ; or, taking the thermal unit as
the energy required, to raise a pound of water 1 C. , the
equivalent must be increased by four-fifths, amounting
to 1390 foot-lbs.
If a pound of good coal were burned and no heat wasted,
it would produce at its full theoretical equivalent 14,000
thermal units of heat, which would raise 14,000 Ibs. of
water 1 C., or 140 Ibs. of water 100, or 70 Ibs. of water
200. A pound of coal theoretically contains heat
18 WATER: ITS ORIGIN AND USE
sufficient to boil 7 gallons of water, so the energy con-
tained in 1 Ib. of good coal expressed in foot-lbs. is 14,000
(units of heat) x 772 = 10,808, 000 Ibs. raised 1 foot. By a
trial of ninety -eight samples of good English coal, a mean
of 14,112 thermal units was obtained, so 1 unit of heat
equals
772 foot-lbs.
0-000388 horse-power per hour.
0-00087 Ib. of water evaporated at 212' F.
(Boiling point of water.)
The British thermal unit (B.T.U.) was first determined
by Joule, who gave its mechanical equivalent as 772 foot-
lbs. or units of work at 60 F. This has been modified
by subsequent experimenters, and the dynamic equivalent
of heat is generally accepted as being 778 foot-lbs.
Heat of Combustion of Various Fuels
This may at first appear to have no connection with our
story, but it is of great importance that we should know
something of the comparative heats of combustion of
various fuels, also the air consumed by each in the process,
and its power for evaporating water, as frequent reference
will be made to these powers in the following chapters.
Total heat of f C " b> /Lo
combustion of of air at 62
lib. of fuel. chemically
consumed.
Coal of average composition 14*700 heat units 140
Coke .... 13-548 142
Wood, desiccated . . 10-974 80
Peat . . 12-297 99
Temperature
Before leaving this subject, it will be as well to bear in
mind that a thermometer measures temperature, and not
heat directly.
TEMPERATURE 19
Temperature is that energy with which one body seeks
to impart its heat to another, and is no real indication of
heat in the body, e.g. equal weights of mercury and water
may have the same temperature, and yet the water will
contain really thirty times more heat than mercury.
Temperature implies that the condition of heat in a
body may be compared with some standard, and the means
of such comparison is the thermometer.
The construction and use of the thermometer is so well
known, that a general description is unnecessary, but it
may be of some interest to know that mercury was not
always used in its construction.
Air has been used for this purpose : it was the substance
first used by Sanctorius of Padua in 1590. His instru-
ment consisted of a simple glass tube, having attached
to it at one end a bulb, the other dipping into some
liquid contained in a vessel below ; as the bulb became
heated the air expanded, and forced down the liquid
in the tube. Mercury, however, is found to be the most
suitable substance ; and as the same body at the same
temperature always has the same volume, and always
suffers the same change in volume with the same change
of temperature, we can easily understand how the
change of temperature causes the mercury in the bulb to
expand or contract, and so stand higher or lower in the
tube, the amount of variation in the height depending
upon the proportion which the diameter of the tube bears
to the capacity of the bulb.
Though the boiling-point of water varies according to
atmospheric pressure, ice practically always melts at a fixed
temperature of 32 F., so the zero of the F. scale is fixed
32 below this point. The interval between the points of
freezing and boiling (212) is divided into 180 equal parts
or degrees (32 + 180 = 212). In the centigrade scale the
20 WATER: ITS ORIGIN AND USE
interval (32- 212 F.) is divided into 100, and the zero
placed at the freezing-point. Mercury freezes at 39 or
40 below zero F., or 71 or 72 F. of frost.
Glass is admirably suited for the bulb and tube of a
thermometer, for it is found by experiment that the dilata-
bility or expansive power of mercury is greater than that
of glass in the proportion of nearly 20 to 1.
It is also necessary that the tube should be made of
some transparent material, so that the position of the
mercury can be seen.
If glass be heated from 32 to 212 F., the increase
in volume is only '00001434, but mercury would be
represented by -00014000.
Where the heat to be measured is beyond the range
of the mercurial thermometer, an instrument called the
pyrometer is used.
Internal Heat of the Earth
The internal heat of the earth commands consideration
here, as it is the principal agent in the formation of
thermal springs, geysers, etc., to which we shall refer
later on. It is found in temperate regions that at a depth
of about 80 to 100 feet in the earth there is an unvarying
temperature. All the world over, from the Arctic region
to the tropics, varying of course with latitude, etc., there
is a constant temperature at a certain depth. For instance,
if it were possible to sink a shaft into the bed of the
ocean to this depth, the result would be the same, the
solar rays having no power to raise the temperature here.
It is stated by Lord Avebury that "the variation of
temperature due to the seasons, etc., does not extend to a
greater depth than 5 feet into the surface of the earth."
4-8 in all things, however, there are exceptions to this
INTERNAL HEAT OF THE EARTH 21
rule, and although the depth to which the seasonal varia-
tions penetrate depends also partly on the thermal con-
ductivity of the soil, rocks, etc., without doubt the cold
of winter and the heat of summer are transmitted down-
ward in successive waves, disappearing at the constant
limit above referred to.
In extreme climates, as we might expect, this zone of
invariable temperature, however, reaches extreme depths.
At Yakutsk, Eastern Siberia (Lat. 62 N.), in sinking
a well the soil was found to be permanently frozen to a
depth of 700 feet. The researches of Sir William Thomson
prove how these apparently phenomenal conditions are
possible. He says : " Any considerable area of the earth's
surface, covered for several thousand years by snow or
ice, and retaining, after the disappearance of that frozen
covering, an average surface temperature of 13 C., would,
during 900 years, show a decreasing temperature for some
depth down from the surface, and 3600 years after the
clearing away of the ice would still show residual effect
of the ancient cold."
In Java at 2 to 3 feet, and in India at a depth of 12
feet from the surface, the thermometer is constant all
the year round.
From observations made in the catacombs at Paris,
which are situated at about a depth of 100 feet from
the surface, there was no change of temperature ; this
depth is called the invariable stratum, and is taken as
having a temperature of 52 F.
From observations taken all over the world, below the
limit of the influence of the seasonal changes we have
described, the temperature has in no single instance been
found to diminish downward ; it always rises. Of course
volcanic regions are excepted.
Beyond the constant limit the temperature is influenced
22 WATER: ITS ORIGIN AND USE
solely by the internal heat of the earth ; the difference
between the temperature at 100 feet and at the surface
is caused by what is called radiation.
Below this depth there is an increase of 1 F. for each
66 feet, or 80 F. at the depth of a mile ; or at a depth
of a little over 2 miles below the earth's surface the
temperature would be 212 F. It is supposed that at a
depth of 20 miles the temperature would be 1760 F., and
at 50 miles 4000 F., at which point every known solid
substance would melt. Some authorities give 1 F. for
every 45 feet, others 52 feet, 55 feet, 60 feet, and 90 feet,
but 66 feet appears to be generally accepted, the highest
being 1 F. for each 41 feet at Glasgow, in the coal
measures.
These minor differences are no doubt due to local
conditions : the kind of rock through which the heat has
to pass, no doubt, has some little influence on the results.
If this rate were kept up, the temperature at the centre
would surpass the imagination of the most fertile brain ;
but the increase cannot be as great as this would show,
for if it were so, according to some estimates the tempera-
ture would be not far short of 200,000 C. We only really
know the condition of heat at a depth of from six to seven
thousand feet.
The hot springs which issue from the earth prove the
existence of great heat within the earth, as also do active
volcanoes. With our knowledge of these slumbering
powers, there is little room to wonder when we hear of an
eruption; it is indeed more wonderful that they should
not be even more frequent and numerous, and of greater
magnitude, than any we have records of.
" The agency of central heat," says Dr Buckland, " and
the admission of water to the metalloid bases of the earths
and alkalies, offer two causes which, taken singly or con-
INTERNAL HEAT OF THE EARTH 23
jointly, seem to explain the production and state of the
mineral ingredients of the crystalline rocks, and to
account for many of the grand mechanical movements
that have affected the crust of the globe."
From observations by the writer, the temperature of
water in wells in the chalk formation 150 feet deep was
found to be 53 F. ; in a well 250 feet deep, 56 F. ; and in
an artesian well in the same locality, 650 feet deep (taken
at the same time), 65 F., or an increase of 12 F. between
150 and 650 feet ; the difference between the two depths
being 500 feet, giving an increase of 1 F. for each 41 '66
feet in depth.
In making the Simplon tunnel (12 miles long), the
tunnelling began from both sides simultaneously. The
greatest obstacles encountered were springs of water
yielding 3700 gallons per minute; finally, in the last
section of the Swiss advance, a number of hot springs were
met with, pouring out 600 gallons of water per minute at
a temperature ranging from 104 to 117 F. The men at
this point had 1 miles of rock over their heads.
During the progress of this work careful observation
was made, and it was found that the increase in tempera-
ture was 1 F. to 71-5 feet, the figure being 977 F. at
2135 metres below the summit. At another position the
vertical gradient worked out at 1 F. to 67'5 feet.
This proves that though the increase of the internal
heat of the earth is, as we have seen, 1 F. for each 66 feet
all the world over, it will not account for the above
temperature, which bears out the statement that where
the heat is considerably in excess of these figures, it must
be due to volcanic agency.
It is, however, hardly satisfactory to take the tempera-
ture of the water from springs, as in the above and similar
instances, for comparison with the depth from which it is
24 WATER: ITS ORIGIN AND USE
drawn ; for, though apparently coming from the level at
which it is found, it is probable that it may really have
its origin at either a higher or a lower level, and so carry
an apparently inaccurate temperature. It must also be
remembered that at some places both hot and cold springs
issue from the earth within a few feet of each other.
In the boring of the Ox-bow tunnel in Idaho, similar
hot springs were met with, the temperature of which
progressed from 95 to 132 F. at the hottest point; this
difficulty was only overcome, and the work enabled to
proceed by the usual method of spraying the walls with
cold water.
If we study the foregoing figures, a simple calculation
will tell us what little distance we have to penetrate into
the earth to come to temperatures such as that of our
domestic fire (1100 F.), of the melting-point of wrought
iron (2912 F.), of platinum (3080 F.), of a Bessemer
furnace (4000 F.), and to that point at which the granite
rocks would melt (20-30 miles).
Such depths as these, compared with the diameter of
the earth (7926 miles), are insignificant, and can be com-
pared to the prick of a pin in the earth's crust.
We who live on the surface of the earth would hardly
give a thought to the existence of the enormous heat
beneath us, were it not for the presence of volcanoes,
geysers, etc., which remind us by occasional eruptions of
their slumbering forces.
CHAPTER II
ATMOSPHERE
" The great instrument of communication between the surface of
the sea and that of the land is the atmosphere, by means of which
a perpetual supply of fresh water is derived from an ocean of salt
water, through the simple process of evaporation." Dr BUCKLAND.
LET us now consider briefly the atmosphere of air which
envelops the globe, without which nothing could live,
nothing could burn, nothing could grow ; without which
no sound could be heard, and there could be no rain. The
more we think of this marvellous envelope, the more
interesting and fascinating it becomes.
Air is a mixture of two gases without chemical change,
unlike water, which is two gases chemically compounded
and forming a liquid.
Dr Saleeby says: "For many centuries air was re-
garded as a single thing, like water.
"It had occurred to no one that air might be, as we
now know it to be, a mixture of gases. This discovery
was the work of Joseph Black, a Scotchman, the outcome
of which was a revision of the doctrine of heat, the dis-
covery of latent heat, and the universal acceptance of the
fact that there is not only one kind of air."
Impossible though it may appear to us, it is nevertheless
a fact that, by a wonderful provision of nature, wet air is
lighter than dry.
One cubic foot of ordinary air at normal pressure (62 F.)
25
26 WATER: ITS ORIGIN AND USE
weighs, when dry, 532'5 grains ; but if saturated, it weighs
only 529 grains, or 3 grains less per cubic foot.
Twenty thousand cubic feet of saturated air at 60 con-
tain 17 Ibs. of water ; if the temperature of saturated air
were 90, the same quantity would contain 47 Ibs. of water.
The presence of this water vapour in the air has the
effect of making a temperature of 30 to 40 feel raw and
cold, 60 comfortable, 100 close and heavy as in a steam-
ing hot-house.
These same temperatures of dry air would not cause
such extreme sensations.
When the atmosphere is charged with vapour, and
contains, in this form, all the water that is to become
rain, etc., it is lighter than dry air; hence one of the
minor causes of the difference in pressure shown by the
mercury in a barometer, which then indicates rain, but
actually shows reduced pressure. The probability of rain,
of course, depends upon the presence of more or less
vapour in the atmosphere, and in the progress of such
changes as ultimately lead to its condensation.
This is the secret of all the wondrous works accomplished
by the atmosphere, beside which all other of nature's
mysteries sink into insignificance. Were this not so, the
whole existence of this globe would have been different ;
and on this fact hang all the mysteries of the air, a few
only of which we will try to trace.
Maury says: "It feeds and nourishes the earth, it is
more simple, more grand, more majestic than the world
of waters, more varied and changeful in its moods of storm
and calm, of ebb and flow, of brightness and gloom.
"The carbonic acid with which to-day our breathing
fills the air, to-morrow seeks its way round the world.
The date-trees that grow around the falls of the Nile will
drink it in by their leaves, the cedars of Lebanon will
COMPOSITION OF THE ATMOSPHERE 27
take of it and add to their stature, and the palms and
bananas of Japan will change it into flowers.
" The oxygen that we are breathing was distilled for us
some short time ago by the magnolias of the Susquehanna,
and the giant rhododendrons of the Himalaya contributed
to it.
" It is an envelope or covering for dispersing light and
heat over the surface of the earth ; it is a sewer into
which, with every breath we draw, we cast vast impurities ;
it is a laboratory for purification ; it is the machine for
pumping up all rivers from the sea, and conveying the
waters from their fountains in the ocean to their sources
in the mountains."
We will therefore devote a considerable portion of our
story of water to trying to follow some of the methods by
which the atmosphere fulfils these many duties, and acts
as one of the principal of nature's agents, raising, purifying,
and supplying to the world pure water and air, two of the
things most necessary to our existence, and on which two
things the whole universe lives and grows, and without
which all other necessaries of life could never exist.
The atmosphere is far older than the earth which it
surrounds, consisting, as we have seen, of the remaining
uncondensed gases left after the complete consolidation of
the thin crust enveloping the earth, having, like the earth
itself, gradually cooled down, until at last it has become
capable of supporting life.
Composition of the Atmosphere
When we feel the breeze gently fanning our cheek, do we
ever realise that the sensation is caused by molecules of
air, so small that 25,000,000 of them, placed in a straight
line, would only measure one inch, which are beating
against our face although we cannot see them.
28 WATER : ITS ORIGIN AND USE
The composition of air is as follows :
By volume. By weight.
Oxygen . . 20-84 23'141
Nitrogen . . . 79'16 76'859
100-000 100-000
It also contains '03 to '04 per cent., by volume, of
carbonic acid. When dry it is 819 times lighter than water.
The average proportion of aqueous vapour contained i-i
air is 1*4 per cent, by volume. It is estimated that the
total weight of the entire atmosphere of the world is
300,000 million tons. Sir John Herschel estimates it to
weigh llf trillion pounds, and to equal in mass 7,500,0^
part of that of the earth itself.
Fire could not be kindled without air, and to consume
1 Ib. of coal 11| Ibs. or 150 cubic feet of air are necessary
to combine with it.
Oxygen is a gas which is the most widely distributed
of all the elements ; respiration, burning, and the produc-
tion of light (electric light excepted) are only possible in its
presence. (See Composition of Water.)
It is the oxygen in the atmosphere that destroys metals,
setting up rust or oxidation on iron; mercury (quick-
silver) cannot withstand its influence under certain
conditions. Iron rust weighs more than the amount of
metal destroyed ; this additional weight is found to consist
of oxygen, which by a chemical process can be re-converted
into gas. It was by carrying out this experiment with red
mercurial powder that Priestley, in 1774, discovered
oxygen.
The nitrogen which forms four-fifths of the atmosphere
represents the inert negative element which, though not
actively hostile to life, by diluting the oxygen, lessens the
activity and rapidity of the energy developed by its
ANALYSIS OF ATMOSPHERE 29
combustion, and thus tends to prolong life. Nitrogen is a
colourless, inodorous, tasteless, incombustible, invisible
gas, incapable of supporting life.
Dr Schofield says that the human being, while resting,
requires about 480 cubic inches of air per minute ; if walk-
ing at the rate of 3 miles per hour, 1550 cubic inches; if
running at the rate of 6 miles per hour, 3260 cubic
inches. The average man requires, to replace the waste of
his body, 7000 grains of oxygen and 300 grains of nitrogen
daily.
The other properties of these gases are of equal interest,
but for the purpose of our story this must suffice.
Analysis of Atmosphere
The average composition of the atmosphere is :
Oxygen 20'61
Nitrogen 7 7 '95
Carbonic acid .... '04
Aqueous vapour .... 1'40
Nitric acid ..... trace
Ammonia ......
Carburetted hydrogen . . .
T , I Sulphuretted hydrogen
In towns \
( Sulphurous acid . .
100-000
(According to Lord Eayleigh, air contains 1 per cent, of
argon.)
Specific Gravity of Elastic Fluids
In order that we may be better able to trace some of
the wonders of the atmosphere, it is necessary that we
should know the specific gravity of air; and for our
guidance and comparison the S.G. of a few elastic fluids
are given.
30 WATER: ITS ORIGIN AND USE
One cubic foot of dry atmospheric air, at 62 F., at normal
pressure weighs 532-5 Troy grains ; its assumed gravity of
1 is the unit for elastic fluids. Therefore the specific
gravity of
Atmospheric air .... I'OOO
Hydrogen -068
Oxygen M02
Nitrogen '971
Carbonic anhydride . . . 1*520
Steam at 212 F '488
Vapour of water .... -623
Carbonic Aeid in Atmosphere
This is more properly known as carbonic anhydride, or
carbon dioxide, and is composed of 12 parts by weight of
carbon and 32 of oxygen ; it is a colourless gaseous com-
pound, without smell, 22 times as heavy as hydrogen. It is
incapable of supporting animal life ; in fact, if it exists in
the atmosphere to an extent of only 4 or 5 per cent., it acts
as a narcotic poison ; it however exists there in a harmless
proportion of 1 volume to 2500.
This compound plays such an important part in our
story that we may with interest trace it a little further.
It is disengaged from fermenting liquors, from decom-
posing animal and vegetable matter. It exists in large
quantities in all limestones and marbles, and is also
found to emanate from the earth, constituting the choke-
damp of the mines, the dangerous gas in our wells,
vaults, and caves.
From its weight it tends to subside into low-lying places,
rendering them uninhabitable, as in the Upas Valley of
Java.
Thus we see that it is fatal to breathe carbonic acid ;
it has its redeeming features, however, when taken into the
EVAPORATION 31
stomach with our food. It exists in all aerated waters and
beverages, from ginger beer to champagne, all of which owe
their refreshing qualities to this gas.
The amount of carbonic acid in the atmosphere has
been found to be, in the London parks, '0301 ; London
streets in summer, '0380 ; Manchester fog, '0679 ; worst
parts of a London theatre, '3200 ; while in a mine in Corn-
wall 2'5000 was found to exist.
The extremely luxuriant forests that covered the face
of the earth millions of years ago, before man's appearance,
and which, by their rapid growth and decay, were destined
to provide our present coal-fields, flourished and grew with
great rapidity, covering the ground with their carbonaceous
trunks, leaves, and branches. This prolific production of
vegetable life was mainly due to the higher temperature
then existing, and the greater proportion of carbon dioxide
in the air ; it must have greatly exceeded what we find at
the present day.
In the accumulation and gradual decay of the luxuriant
vegetable growth in the forests of past ages, which in course
of time were buried and overwhelmed by floods, undergoing
chemical changes, and suffering the loss of certain gases,
we find a most interesting cycle of transformation, which,
aided by gradual compression, resulted in the formation
of coal.
Evaporation
The first process in the formation of cloud and atmos-
pheric water is evaporation, or the conversion by heat of
a liquid or a solid into vapour, which becomes dissipated
in the atmosphere in the form of an elastic fluid.
We will consider only the passing of water by natural
process into the atmosphere, where it remains, generally
invisible.
32 WATER: ITS ORIGIN AND USE
If water be spilled upon the ground on a hot day, it dries
up ; that is to say, it is quickly converted into invisible
vapour. The small pool by the roadside, lakes, the mighty
ocean, the fields of snow and ice, are all evaporating,
eventually forming clouds and rain.
Newly-fallen snow is at times the sport of the wind,
and is frequently wafted from the summit of a mountain
in the form of a vast banner. Professor Tyndall tells us
he has seen it gradually melt away in the air, and again,
by condensation, curdle up into true white cloud ; this in
turn would be pulled asunder like carded wool, and reduced
a second time to transparent vapour.
The effect of evaporation is always to reduce the tem-
perature of the evaporating surface. The lowest artificial
temperature ever produced was obtained by the evapora-
tion of volatile liquids such as ether.
The evaporation from our bodies is one of the most
obvious causes of diminution of temperature. We possess
2,000,000 perspiration glands, in connection with 10 miles
of ducts. It is calculated that the available energy derived
from oxidation of the organic matters of the food of a well-
fed man equals about 2,700,000 units of heat (the unit
being the amount of heat required to heat 1 gram of water
1 C.). Bodily heat is diminished by the skin, lungs, etc.
By radiation and evaporation from the skin, about 75 per
cent, is lost. In cold weather the loss by radiation is
increased, and that by evaporation is proportionately
decreased ; and under reverse climatic conditions we find
a greater increase in the evaporation and a decrease in the
radiation. The loss of bodily heat by the lungs is equal to
20 per cent., and is fairly constant at all temperatures.
This accounts for 95 per cent. ; the remainder, 5 per cent.,
is disposed of in other ways.
When a man is not exerting himself in any way, nature
EVAPORATION 33
dissipates the heat from the body in the following
manner :
Units of Per
heat. cent.
In raising the temperature of food . 70,157 or 2 -6
In warming inspired air . . 70,032 2'6
In vaporising the water of the lungs . 397,536 14'7
Lost by radiation, conduction, and I
,.,,,,. f
evaporation from the skin . ;
2,700,000 100-0
Here we see nature's system of evaporation and radiation
at work in our bodies.
If we apply this principle to the heat absorbed in the
evaporation of water to form the vapour in the atmosphere,
and set free in the re-condensation of the vapour into rain,
it may perhaps help us to grasp this part of nature's
wonders in connection with our subject.
One other practical example of the reduction of
temperature by evaporation. In hot climates water is
made to freeze during clear, cold nights by leaving it
overnight in porous vessels or bottles wrapped in
moistened cloth. This is entirely due to the cold pro-
duced by the evaporation from the porous vessel or by
the evaporation of the water in the moistened cloth
surrounding the bottle.
Water requires a greater expenditure of heat to evapor-
ate it than any other liquid. As much heat is required
to evaporate a pound of water as would raise 966*6 Ibs.
1F., or about 5J Ibs. from freezing to boiling. (See
Latent Heat of Steam.)
This heat is stored up in the vapour, and given out again
when the vapour is converted into water. In cold, cloudy
weather we often hear the expression used, "It will be
warmer after the rain " ; and there is more in this remark
than a casual observation would lead us to think, for,
34 WATER: ITS ORIGIN AND USE
"every gallon of rain that falls has yielded to the
atmosphere that surrounds the place where it was con-
densed as much heat as would raise 5^ gallons from
freezing to boiling."
Evaporation varies with the distance from the equator,
and from many other causes. The glaciers, ice, and snow
on the mountain summits, where the temperature is far
below freezing, are continually evaporating.
The sun pours its heat on the water in the tropics and
evaporates it. Stored with this heat the vapour is borne
away and converted into rain, giving up its store of heat
when it encounters a lower temperature.
Hartwig says: "Neither storms nor ocean currents,
nor ebb and flood, however great their influence, cause
such considerable movements of the waters, or force them
to wander so restlessly from place to place as the silent
and imperceptible action of the warming sunbeam." He
considers that the whole of the aerial and terrestrial
migrations of the waters of the globe are due to evapora-
tion, and the counter-currents thus induced in both air
and water.
" To liquefy ice, a large quantity of heat is necessary.
" To vaporise water a still larger quantity is necessary,
as this heat does not render water warmer than ice, nor
steam warmer than the water.
"To convert a pound weight of tropical ocean into
vapour, the sun would require to expend 1000 times the
amount of heat necessary to raise 1 Ib. of water 1 degree
in temperature."
This same quantity of heat which would raise 1 Ib.
of water 1 degree, would raise the temperature of 1 Ib. of
iron 10 degrees ; thus to convert 1 Ib. of the tropical ocean
into vapour, the sun must expend 10,000 times as much
heat as would raise 1 Ib. of iron 1 degree in temperature.
VAPOUR 35
" This quantity of heat would raise the temperature of
5 Ibs. of iron 2000, which is the fusing point of cast iron,
when passing into the molten condition.
"Imagine the mighty glaciers, etc., to be, instead of ice,
a mass of molten iron, white hot and of quintuple the
weight, and you get some notion of the enormous heat
paid out by the sun to produce the present glacier.
" This is as clear as day, and a diminution of the sun's
rays would not produce an extension of our glaciers, but
the reverse.
" More heat instead of less, and the corresponding con-
densation alone could produce a 'Glacial Epoch'" (Tyndall).
Vapour
Vapour is really the term applied to designate the
gaseous form which a solid or liquid substance assumes
when heated. Vapour is therefore essentially a gas, and
most gases are now proved to be liquefiable.
There is no physical difference between steam and
vapour ; but for the purpose of our story we shall associate
vapour with the natural passing of water into the
atmosphere invisibly.
Aqueous vapour formed on the surface of the land and
water is always present, mixed with the atmosphere, and
when it meets with a sufficient reduction in temperature,
it condenses into water in the form of rain or dew, etc.
If the air were perfectly dry, the heat radiating from
the surface of the earth, as well as the solar radiation,
would pass through it without it being sensibly warmed
thereby add vapour and its diathermancy is diminished.
So with an increase of vapour or with increase of humidity
both solar and terrestrial radiation are much less felt on
the surface of the earth.
36 WATER : ITS ORIGIN AND USE
" Vapour is perfectly transparent to light, or luminous
heat rays. It does not occupy more perhaps than ^^ of
the space occupied by air : that is, it is present in very
small proportion; yet it stops more than 100 times as
much heat as all the air together 20,000 times as much
as an equal quantity of air.
"So impervious is it to heat, that no inconsiderable
portion of the heat radiated from the earth is stopped
within the first thirty or forty feet, probably not less
than half.
" Vapour water acts as glass ; lets the heat of the sun
through, but will screen you from the heat of the fire. It
also admits and then detains the heat of the sun.
"The temperature of our planet is higher and much
more equable than it would be but for this singular pro-
perty of vapour " (J. M. Wilson).
If vapour existed alone, and not in combination with
air, as is fortunately the case, cloud would form only at
one level. There would be only one temperature at
which vapour could change into a liquid, and form rain.
The level and temperature would alter with the time of
day and season.
Weight of Vapour
"In pure dry air at sea level, with the barometer at
30 inches, we shall find that at 32 F. the column of
mercury 30 inches high, resting on 1 square inch, weighs
14'7 Ibs., mercury being 13*6 times as dense as water, air
only Y^g<y as dense. The weight of a cubic foot of dry
air under these conditions will be about 565 grains (Troy).
On the top of a mountain 18,000 feet high it would weigh
only half as much.
"The weight of a cubic foot of watery vapour, under
WEIGHT OF VAPOUR 37
'the same conditions, would be only 352 grains; so when
vapour is mixed with dry air, the resulting compound is
lighter : that is, damp air is lighter than dry air "
(D. Archibald).
The elasticity of vapour varies with the temperature.
At F. it is capable of sustaining a pressure of 0*044
inches of the mercurial bar; at 32 F., 0*181; at 60 F.,
0-518 ; at 80, 1-023 ; at 100 F., 1-918, which is nearly ^
of the average pressure of the atmosphere.
" The quantity of the atmosphere which covers the
globe must be practically unchangeable. On the other
hand, the amount of aqueous vapour in the air is con-
stantly varying.
" A cubic foot of dry air at sea level and 50 F. temper-
ature weighs nearly 547 grains ; a cubic foot of vapour the
same temperature weighs only 4'1 grains. The air is 133
times heavier than the vapour. Hence the more moisture
distributed through the atmosphere, the less pressure
shown by the mercury in the barometer tube.
" We cannot at any moment tell how much the fall of
the barometer is due to the presence of vapour or precipi-
tation of rain, or actual removal of the air by cyclonic
movements ; but water in one form or another must have
a notable influence " (Science Notes Daily Telegraph).
At a height of 23,000 feet, the amount of vapour in the
air is only fa of that which exists at sea level ; while at
46,000 feet it would be only r foj.
Cirrus clouds have been seen at this altitude. Long
before water vapour has reached 37 miles a great deal is
lost by being condensed into rain.
At a height of 9 miles above the surface, the actual
amount of vapour present is only 7^ of what would exist
if it were incondensible.
It is the water vapour in the atmosphere that causes it
38 WATER: ITS ORIGIN AND USE
to rise, as it is lighter than the air (see Specific Gravity
of Elastic Fluids, p. 29 Atmosphere).
" When a mass of air containing only a small proportion
of vapour rises, it cools at the rate of 1'6 F. for every
300 feet it ascends, or about 5'2 in ]000 feet.
" When the air contains as much as it can hold invisibly,
or is fully saturated, it is different; it ascends, cools,
condenses into cloud, and finally falls as rain, giving out
the heat which it absorbed in the act of conversion from
water into vapour.
" This heat is latent so long as it is vapour, becomes
patent as it condenses, and retards the cooling of such a
mass of air; it only cools | F. in ascending 300 feet"
(Archibald).
Saturation of Air
Saturation is the term used when the air is saturated
with aqueous vapour, when, if the temperature is slightly
lowered, condensation takes place. The degree of satura-
tion is measured by an instrument called the hygrometer.
Air at a temperature of 32 can contain, in the state of
vapour, the y^Q part of its own weight, and that amount
is doubled with every 27 rise in temperature ; so that at
59 the air can contain ^ part, and at 86 ^ part ; but it
is seldom that it is so fully saturated.
A given space can only contain a certain amount of
vapour. When it can hold no more it is said to be fully
saturated. Whether there be air or not in the space does
not affect the quantity of vapour.
If the space be a vacuum, it is immediately filled ; if
there be air in it, the evaporation goes on slowly. Just as
hot water can contain more salt than cold water, so hot
air can contain more vapour than cold.
TYPICAL NATURAL WATERWORKS.
The sun lias raised the moisture up into the cloud. The mountain forms a natural condenser ;
the suowfields and glaciers act as storage reservoirs holding the water "locked to solidity" in
reserve. The small glacier stream conducts a continuous supply into the little lake, which forms
a service reservoir, whence a stream acts as nature's distributing agent.
[ To face p. 38.
CONDENSATION OF VAPOUR 39
Condensation of Vapour
The condensation of vapour is frequently referred to in
the following chapters; it is the turning of steam or
vapour back into water. Thus when a cold east wind
meets a warmer current, the moisture which this latter
contains is condensed, and we have rain, or natural atmos-
pheric condensation.
The artificial condensation of steam and the formation
of a vacuum by the injection of cold water to condense the
exhaust steam into water, now in general use, was first
applied to the steam engine in 1705 by Thomas Newcomen,
a locksmith of Dartmouth, Devon, but this is somewhat
outside the scope of our subject.
Vapour and its Effects
Atmospheric water exists in three states: vapour
(gaseous), water (liquefied, as rain), solid (ice, snow, hail).
It is, however, only in the form of vapour that we shall
consider it here.
Were it not for the particles of vapour and dust in the
air, there would be no refraction of light, no twilight
or dawn.
Where the air is very rarefied, as at Quito and Lima,
twilight is said to last only twenty minutes.
In India there is but little of this beautiful phenomenon
to be seen.
" The sun's rim dips, the stars rush out,
At one stride comes the dark."
COLERIDGE.
There can be no twilight on the moon, for, as we have
seen, this luminary possesses no air.
Now the sun is apparently visible, and its rays con-
tinue to reach us for some considerable time after it has
40 WATER : ITS ORIGIN AND USE
set, for though the rays of light cannot reach us directly
they do so by refraction.
Light from the sun travels through millions of miles of
pure ether, and suffers no refraction until it strikes our
atmosphere.
It is a well-known fact that the setting sun has actually
sunk completely beneath the horizon at the moment when
it appears to us to be first in contact with it, and when
the upper limb is just about to disappear it is actually 36'
below the horizon.
Atmospheric refraction is the apparent angular elevation
of the heavenly bodies above their true places, causing
them to appear higher than they really are.
Therefore, the more obliquely the light enters the atmos-
phere, the greater will be the refraction. It is from this
cause that the sun, when near the horizon, either at sunrise
or sunset, appears to be elliptical, the long axis being hori-
zontal, from the fact that the light from the upper part of the
disc is not so strongly refracted as that from the lower part.
Therefore refraction is greatest when the body is on the
horizon, and diminishes all the way to the zenith, where
it disappears.
In passing through the upper layers of air, the rays get
bent and reflected, and, in spite of the curvature of the
earth, we get brilliant skies after the sun has set.
As an illustration of the fact that floating particles of
vapour and dust in the air reflect light, we may instance a
ray of light penetrating into a dark room through a hole
in the shutter, which diffuses sufficient light to illuminate
feebly the apartment.
Were it not for this, the sun would set, and darkness
immediately overshadow all, where now we get twilight
until the sun is 18 below the horizon, and night approaches
gradually.
" With the sun as shown, it will just have set to an observer at 1,
but all the air within his range of vision will still be illuminated.
When by the earth's rotation he has been transported to 2, lie
will see the ' twilight bow ' rising in the east. When he reaches
3, the western half only of the sky remains bright. When he
reaches 4, only a glow remains in the west ; and when he come
to 5, night closes in upon him. Nothing remains in sight
which the sun is shining."
ATMOSPHERIC EEFRACTION (Dr Mill, The Realm of Nature).
A observer. *, true position. *', apparent position of sun.
JThe densenessof the atmosphere is indicated by the closeness of the lines
[To face p. 40.
VAPOUR AND ITS EFFECTS 41
For the same reason, we have the gentle daybreak, and
gorgeous coloured skies, both morning and evening, instead
of an immediate transition from light to darkness or dark-
ness to light.
Nearly all the celestial phenomena arise from this re-
fraction of light. Chambers, in his Story of the Solar
System, attributes even the twinkling of the stars to this
cause.
The word twilight is of Saxon origin ; it implies the
presence of twin or double light, and applies to the dawn
(break of day) as well as to the approach of evening,
generally known by the name of twilight.
The sun having set, it still continues to light the clouds,
and when thus illuminated they reflect some of the sun's
light, producing these half-lights.
" The duration of this light depends on the position of
the observer, the season of the year, and the condition of
the atmosphere. In the tropics 16 or 17 puts an end
to the phenomenon. At the equator the duration is about
seventy minutes ; at the latitude of Greenwich two hours ;
and so on towards the Pole. At each pole in turn the sun
is below the horizon for six months ; but as it is less than
18 below for three and a half of those six months, it may
be said that there is a continual twilight for three and a
half months.
"At the latitude of Greenwich, from 22nd May to 21st
July there is no true night, but constant twilight from
sunset to sunrise, or two months' twilight in all "
(Chambers).
I often wonder how many of my readers, when they see
the glorious colours of the sky, think of the manner in
which nature enables us to realise their beauty and
variation.
Light and colour are impressions produced by vibrations
42 WATER: ITS ORIGIN AND USE
of the ether on the retina of the eye. When 700 millions
of millions of vibrations strike the eye in a second we see
violet; 400 millions of millions give us the impression
of red.
The optical illusion called mirage is, like the coloured
skies, caused by the reflection of the light through masses
of air of various density.
In this manner apparent elevations, coasts, mountains,
and phantom ships are formed ; in deserts the illusion
takes the form of lakes. At times it appears to invert
existing objects, or to repeat an object above its true
position.
The Fata Morgana seen on the Calabrian coast is a
phenomenon of this kind, men and animals of enormous
size being represented in the air.
Without vapour or minute particles of water in the air,
these would be impossible.
Temperature of Atmosphere
The air resting on the earth becomes warmed by con-
tact with it, and by the radiation from its surface ; but in
the temperate zone, as we ascend above the earth's surface,
the temperature diminishes.
The rate of diminution decreases as we rise, from 7 in
every 140 feet near the surface to 1 in every 400 feet at
a height of 10,000 feet, the total diminution from sea level
up to 10,000 feet being 34, or an average of 1 in 300
feet. In India at 10,000 feet the rate is 1 in 270 feet.
The lowest air temperature recorded was registered in
a free balloon ascent from St Louis in December 1905,
when 122'1 F. was found. This was almost equalled at
Vienna on 2nd March 1905, when -1217 F. (154 of
frost) was registered at a height of 31,880 feet. At greater
TEMPERATURE OF ATMOSPHERE 43
heights up to 37,300 feet, the temperature, though more
than 100 below zero, was not quite so low as that quoted.
The mean temperature of London is 46'9 F.; the mean
summer temperature 62 F. ; and the mean winter tempera-
ture is 40 F.
If we take the mean temperature of London as being,
say, 50, snow-line would be reached at about 4500 feet.
At the earliest period of the earth's history, the tem-
perature of the atmosphere depended principally on the
mass of molten matter forming the earth. As this cooled
the temperature was governed more and more by the
radiation of the sun's heat from the land and sea, and not
from the rays of the sun passing through the atmosphere,
and internal heat now suffices to raise the temperature no
more than y^ of a degree.
Tyndall says : " Solar beams, powerful enough to fuse
the snows and blister the human skin ; nay, it might be
added, powerful enough when concentrated to burn up
the human body itself, may pass through the air, and still
leave it an icy temperature. "
The altitude of the sun also has considerable effect on
the amount of heat radiated.
When the sun's rays are vertical, we get nearly its full
power ; but when the rays are inclined we get proportion-
ately less, the same rays having to cover a larger area of
the earth's surface. The power of light also varies in like
proportion. This is in fact the cause of the variation of
light and heat in different seasons, and on different
portions of the globe.
This will be strikingly apparent if we call to mind the
fact that at the end of December, when we in England are
experiencing the severe conditions of winter, the earth is
3,000,000 miles nearer the sun than it was at the end of
June.
44 WATER : ITS ORIGIN AND USE
This is due to the earth's describing an ellipse and not a
circle round our luminary, and proves that a few millions
of miles either nearer or further away is of minor im-
portance compared with the angle at which the sun's rays
strike the earth ; for we get the maximum heat when the
rays fall directly on us, and a minimum of heat when they
are most inclined.
Twenty- five per cent, of the heat falling vertically on the
upper surface of the atmosphere is absorbed thereby, and
75 per cent, only reaches the earth. When, therefore,
the sun's rays are inclined at an angle of 50, only 64
per cent, reaches us ; if at an angle of 10, only 16 per
cent. At sunrise and sunset the sun has only 73^5 part
of its brilliancy at midday, when directly overhead. In
the same manner, in winter (speaking of the northern
hemisphere) the earth is nearest to the sun, and in
summer the furthest from it, the difference being occasioned
not by the distance, but by the more or less oblique
direction of the sun's rays.
We have seen that the earth receives the sun's heat
direct, while the air receives it by radiation from the
earth's surface ; therefore, the further we get above the
earth, the colder the air becomes.
We have also seen that in England we can, by varying
our altitude by 300 feet either way, gain or lose say 1 F.
To obtain a like result from travelling north or south,
taking the temperature of the North Pole as O c F., and
that of the equator as 80 or 90 F., we should have to take
a journey 70 or 80 miles.
The greatest ranges of temperature of the lowest atmo-
spheric stratum, between day and night, occur in the driest
parts of the earth. In the interior of the continents, such
as the Sahara, Desert of Gobi, etc., the difference often
amounts to 40 F. The smallest ranges of temperature
it/W i'ERT 1C A <-
OVER HEX D
DIAGRAM SHOWING THE AREA COVEKED BY A CERTAIN WIDTH OF SUN'S RAYS
AS THEY FALL EITHER VERTICALLY OR INCLINED.
DIAGRAM SHOWING THE THICKNESS OF THE ATMOSPHERE TRAVERSED
BY THE SUN'S RAYS WHEN VERTICAL OR INCLINED
'To face p. 44
TEMPERATURE OF ATMOSPHERE 45
occur in small oceanic islands, such as Madeira, Bermuda,
etc., where the difference between day and night does not
exceed 5 F.
Were the earth deprived of its atmosphere, the tempera-
ture at the equator would be 94 F. below zero, and that
at the Poles would be 328 F. below zero, and the mean
temperature of the whole globe 138 F. below zero a
terrible frost. With the protection of our atmosphere, the
average temperature near the surface is about 60 F. a
delightful temperature.
Thus we see this atmospheric mantle supports life, acts
as a blanket keeping the earth warm, and it also protects
us from falling meteorites.
Many planets have not progressed towards solidification
so far as our earth. Jupiter has not yet cooled to the
same extent, and is supposed to be partly self-luminous,
having an atmosphere containing all the substances which
have, on the earth, long since been condensed into liquids
and solids. This is due to its enormous size, its diameter
being nearly eleven times that of the earth, and it would
therefore take longer to cool.
In the moon, however, we see a picture of the more
advanced stages of this wonderful transformation of
vapour into liquids and solids. Here the smaller body
has cooled more quickly; not only is there no gas, but
no liquids, no air, therefore no life all has been absorbed
into the solid substance of the moon.
Sir Eobert Ball gives us a graphic description of the
mountain scenery in the moon, where the disintegrating
influences of the atmosphere are not at work. "The
absence of air and water from the moon explains the
ruggedness of the lunar scenery. The cloud - capped
towers, the gorgeous palaces, the solemn temples have
but a brief career on earth. It is chiefly the incessant
46 WATER : ITS ORIGIN AND USE
action of water and of air that makes them vanish like
the ' baseless vision.' On the moon these causes of dis-
integration and decay are absent. It seems probable
that on the moon a building would remain for century
after century just as it was left by the builders. There
would be no need for glass in the windows, for there is
no wind and no rain to keep out; there need not be
fireplaces in the rooms, for fuel cannot burn without
air. Dwellers in a lunar city would find that no dust
could rise, no odours be perceived, no sounds be heard."
Professor Giinther of Freiburg University predicts
that the time will come when there will not be sufficient
water on this globe to support human life, and that it
will eventually disappear into the cavernous interior, as
in the case of the moon. Both the former and the latter
are mere speculations and are not accepted as facts, but
their ingenuity makes them worth repeating.
I trust my readers will not think this a digression,
for it has a distinct bearing on our story, as it tells us
that the source of all our water (the atmosphere) will
not always remain in its present apparently permanent
condition, though there are scientific reasons given to lead
us to believe that our earth will never be so absolutely
devoid of atmosphere as the moon ; and although it will
never concern us, we may at least be gracefully thankful.
Compression of Atmosphere
Air may be compressed almost indefinitely ; the pressure
of one atmosphere will halve the volume of air. By the
time pressure equal to three atmospheres has been put
on, it will be found to occupy only one-third of its space,
and so on.
Another example will perhaps make it clearer. If
COMPRESSION OF ATMOSPHERE 47
6 cubic feet of air at ordinary atmospheric pressure be
compressed until they occupy only 3 cubic feet of space,
the pressure of the air would rise to that of two
atmospheres, or the barometer at the commencement
would register 30 inches, and after the compression 60
inches.
Compressed air has been used as a motive power for
many years. A French engineer, Papin, first put it to
this useful purpose about two hundred years ago.
In 1843 passenger trains were by this means run at
a speed of 70 miles per hour between London and
Croydon. Compressed air was, however, abandoned for
this and other similar large purposes, but we still have
parcel and letter delivery by its means. Pneumatic tools
of the most useful and ingenious kind are now used for
many purposes, including the work of boring for water.
There are also air lift-pumps, where water is raised
from deep wells by the force of compressed air only, no
pump valves being necessary. We also use compressed
air for inflating our bicycle and motor-car tyres, and many
other purposes.
We should also remember that most pleasant of all
uses that compressed air is put to, viz. the production
of music ; above all in the king of instruments, the organ.
Any person who is not moved by the grandeur of our
cathedral organ cannot possess a soul.
This calls to mind an anecdote related by that well-
known raconteur, the late Dean Hole.
As a chorister I had attended the choir festival, which
was followed by the usual spread, to which, as might
be imagined, we choir boys did ample justice. Among
several stories related for our edification and amusement,
one impressed me more than any. At a certain church
the Dean gave out the number of the hymn and waited
48 WATER: ITS ORIGIN AND USE
for the playing of the same, but there was no sound from
the organ. He again repeated the number, and again. At
last the organ-blower thrust his head through the oak
screen and called out aloud, " Please, sir, she's bust ! "
The Dean probably told us how the congregation received
the news, but I have forgotten it.
Only those who have been organists can fully appreciate
the pranks played by the vapour in the atmosphere on the
mechanism of the organ. With certain alterations of the
temperature the delicate parts of the organ are affected,
and before the days of pneumatic organs the " trackers "
would often hang up, causing the pipes to continue to
pour forth sound longer than was desired. It was a
common occurrence to find notes cyphering, and little did
the congregation think that, shortly before the service,
the organist had been crawling all over the dusty interior
of his instrument, fixing elastic bands with pins on the
defective trackers to help them to " shut up."
Expansion of Air
Dry air expands or contracts uniformly '002039 its
volume, per degree Fahrenheit, under constant pressure,
or but one volume for each 493 of temperature through
which it is raised, and, like all other elastic fluids, this
expansion is uniform at all temperatures.
If air be heated in a confined chamber, its pressure
increases in direct proportion to its rise of temperature.
If air be suddenly compressed, its temperature rises
in proportion, and if suddenly allowed to expand, the
temperature falls.
The suddenness is only necessary to enable the altera-
tion of temperature to be detected before it escapes.
One thousand volumes of air at C. become 1*3665
EXPANSION OF AIR 49
volumes at 100, i.e. I volume of air at O 8 C. increases
to 1-003665 at 1 C.
The amount of increase in volume for 1 C. is -003665,
and approximately equals 5 } 3 , this fraction being the
co-efficient of expansion for air.
Thus, for every increase of 1 C. , the volume of the gas
is increased 2 fj of its volume.
Therefore, 273 volumes at C. are changed into 274
volumes at 1 C., and 275 volumes at 2 C.
It likewise contracts uniformly on the reduction of
temperature.
For every degree which gas is cooled below C. it
should lose ^73 of its volume ; therefore, if cooled through
273 C. below zero, it would occupy practically no space
whatever.
This is called the absolute zero of temperature, viz.
-273 C. (-459F.).
Such temperature has never yet been reached, and in
such extreme cold gas would not exist as such.
The greatest artificial cold ever produced was 330 below
zero F. This was accomplished by Professor Dewar.
If there were no expansion and diffusion of air, the
separate gases of which it is composed would all lie in
layers one above another, the lightest at the top. This
would be the water vapour ; next, the nitrogen, then the
oxygen ; at the bottom next the earth the carbonic acid.
Kesult to us, death.
It will no doubt be asked why all these points are con-
sidered here ; but air and vapour, under the influence of
these laws of compression and expansion, due to the action
of heat and cold, are really the cause of wind, storms,
cloud, rain, snow, ice, and all the varieties of atmo-
spheric phenomena.
50 WATER: ITS ORIGIN AND USE
Height of Atmosphere
The height of the atmosphere is not known. Probably
we shall never know exactly where air ceases to exist and
the boundless region of space or vacuum commences.
Some idea of the thickness of this sea of air is obtained
from the point at which meteorites become visible. This
interesting phenomenon has always attracted the attention
of the poets. From Tennyson we get
" Now slides the silent meteor on, and leaves
A shining furrow."
And Byron sings
" As stars that shoot along the sky
Shine brightest as they fall from high."
Though they may have fallen millions of miles, they are
invisible until they come in contact with our atmosphere,
at about 100 miles from the earth, when by friction
through it they become incandescent, and we can then see
them, usually at a height of from 40 to 80 miles.
They generally burn out and disappear at an altitude of
about 25 miles ; but portions of their bodies frequently
reach the earth. When this happens it is usually a single
aerolite or meteoric stone; but frequently several have
been known to fall. In several instances thousands
have been obtained : as in the fall of L'Aigle in 1803, at
Knyahinya in 1866, and Pultusk in 1868.
Meteorites consist principally of iron and siliceous
matter. Some are of large dimensions. One mentioned
by Pliny and seen in his day fell at ^Egospotami in 467 B.C.,
and is described as being as large as a waggon.
These stones have been seen to break up into several
pieces when about 90 miles from the earth. Some are
known as detonating meteors. The explosion of one that
HEIGHT PENETRATED 51
fell in Kansas, U.S.A., was heard 60 miles off, and was
supposed to have been heard 150 miles distant.
Their velocity is rarely under 10 miles per second ;
seldom over 40 or 50 miles ; the average being about 30
miles per second.
On 27th January 1906 a very brilliant meteor was seen
to pass over East Lincolnshire, at an altitude of 40 to 50
miles, and its velocity was about 24 miles per second.
Its brightness was equal to the full moon, and its trail of
light lasted for several minutes.
From similar observations it is concluded that the height
of the atmosphere is at least 120 miles; but in an ex-
tremely attenuated form it may reach 200 miles.
Observations made at twilight, on account of reflection
of air and vapour and dust particles in suspension, give
about 50 miles.
It is supposed that the atmosphere of the sun is 500,000
miles deep ; but we must bear in mind the size of this body,
compared with that of our earth, as it probably accounts
to some extent for the great difference in depth.
Height Penetrated
The atmosphere has been penetrated to a height of 37,000
feet, at which point the ordinary person becomes insensible.
This is probably the greatest height to which man will
ever be able to ascend without an artificial supply of
oxygen. In September 1862 Messrs Glaisher and Coxwell
made an ascent from Wolverhampton, reaching an elevation
of 37,000 feet (7 miles), which is the greatest altitude yet
attained.
Mr Glaisher became insensible. His companion's hands
were so severely frozen that he was compelled to use his
teeth to open the valve and so enable them to descend.
52 WATER : ITS ORIGIN AND USE
Dr Berson of Strassfurt found the temperature at
about 20,000 feet to be practically constant at all seasons
of the year, varying from -14 to -19 F. On 4th
December 1894 he ascended to 22,000 feet, feeling some
discomfort from reduced pressure ; but by the assistance
of a cylinder of compressed oxygen, fitted with a tube for
breathing through, he attained an altitude of 31,800 feet
without serious discomfort. The temperature here was
-54 F.
On 31st July 1901 another ascent was made, Dr. Berson
reaching 33,790 feet. Up to 29,000 feet no unusual sensa-
tions were experienced. Up to 33,600 feet observations
were continued regularly, though consciousness was tem-
porarily lost for brief intervals. Soon after this one of
the observers resisted all efforts to arouse him ; his com-
panion opened the valves, so as to bring about a descent, and
then himself became unconscious through the exertion of
this action. Neither of them awoke for one hour, the
balloon being then at about 16,000 feet.
When the above altitude (33,790 feet) was reached, the
balloon was still ascending and would have gone higher.
The thermometer registered freezing point at 12,470 feet ;
at 33,600 feet -40 (Geographical Journal, 1901).
Self-registering instruments affixed to balloons in France
gave the following temperatures :
Altitude 49,000 feet - 90 F.
59,000 - 101* F.
Major B. F. S. Baden-Powell (20th March 1907), in an
address to the members of the Royal Meteorological Society
on "The Exploration of the Air," tells us that small
balloons carrying self-recording instruments had ascended
to the enormous altitude of 82,000 feet, or nearly 16
miles, above the surface of the earth,
PRESSURE OF ATMOSPHERE 53
On 17th May 1907 balloons were liberated from the
Physical Observatory at Pavia (near Milan), when the
recording instruments they carried indicated a height of
74,150 feet, and the thermometers registered a temperature
of 77'8 below zero F.
The highest kite ascent as yet made was accomplished
in Lindenberg Observatory on 25th November 1905. By
a team of six kites an elevation of 21,096 feet was
attained, 9 miles of wire being paid out.
The pressure at the highest point was 12'99 inches, and
the temperature 13 F., the temperature at the surface
being 40-8 F.
For permanent habitation, it is found to be prejudicial
to live at a greater altitude than 15,000 feet, our respira-
tory and other organs not being constituted to withstand
the conditions of temperature and reduced pressure that
would be encountered above this height ; though we would
not be affected by any chemical alteration in the pro-
perties of the air, for its composition is quite as suitable
for man at great heights as at sea-level.
Dr W. N. Shaw, F.E.S., tells us that the greatest cold
yet discovered at high altitudes was over the equator,
where the fall of temperature was found to be continuous
as the balloon ascended ; so the coldest spot known on
earth, or rather off the earth, is the air 9 or 10 miles
above the equatorial belt, where the temperature is lower
than any yet reached in the atmosphere within the
Arctic Circle.
Pressure of Atmosphere
The weight of air = 8 ^ T times that of water. A cubic
foot of air ='07646 Ib. at 62 F., and 13'0777 cubic feet of
air = 1 Ib. A column of air at 32 F. and 1883 feet high =
I Ib. pressure per square inch. A column of water, to exert
54 WATER : ITS ORIGIN AND USE
a similar pressure, would only require to be 27727 inches
high (62 F.), and mercury at 32 F. only 2'036 inches
high.
The barometer was discovered through the failure to
draw water from a deep well in Florence, where, after
infinite pains, it could be made to rise no higher in the
pump than 33 feet.
Galileo was consulted, and concluded that the atmo-
sphere had weight, and that a column of water 33 feet in
height was as much as the weight of the atmosphere could
balance.
It was Evangelista Torricelli, an Italian (born 1608,
died 1647), who discovered that a column of water 32 feet
high balanced the pressure of a column of atmosphere of
equal diameter, and that 2 feet 4 inches of mercury pro-
duced a similar result.
Pascal discovered that, in ascending the Puy de Dome in
Auvergne, the mercury fell to 247 inches, and in descend-
ing again rose to 28 inches, proving that there was less
pressure at the top of a mountain than at the base, and
that the mercury was really supported by the weight of
the atmosphere.
A cubic inch of mercury weighs '49 lb., and 30 x '49 =
147, which figure represents the weight of the atmosphere
over 1 square inch of surface. Therefore, it exerts a
pressure of 147 Ibs. on every square inch of mercury,
which is 13 '6 times heavier than water, so we have
OA k- "I QA
feet = 34 feet, or the theoretical limit beyond
im
which water refuses to rise. In practice 25 feet is the
figure commonly considered as the workable limit.
The outcome of this discovery was the barometer.
There are two kinds of mercurial barometers the
"syphon" and the "cistern." The familiar instrument
PRESSURE OF ATMOSPHERE 55
with dial and pointer, commonly called the weather-glass,
the Fitzroy barometer, and others, are but modifications
of these two.
Although in the present day mercury is almost uni-
versally used in the construction of the barometer, some
of my readers may not be aware that all liquids will
answer this purpose, though not equally well, one point in
favour of mercury being that it does not give off vapour
at moderate temperatures ; if it did so the space in the
tube above the column would fill with vapour, and so
cause the instrument to be inaccurate. Again, the specific
gravity of mercury is greater than that of any other
liquid, and therefore a shorter column is required (say 30
inches) to balance the atmosphere.
If made of water the tube would require to be about
34 feet high, the specific gravity of mercury being 13-6
times greater than water (13*6 x 2*5 = 34).
If made of glycerine the tube would require to be 27
feet high, and so on, according to the specific gravity of
the liquid employed.
The aneroid barometer consists of a circular metallic
chamber, partly exhausted of air and hermetically sealed ;
it has corrugated concentric circles on its upper and under
surfaces. The varying pressure of the air depresses or
elevates the surface of this chamber. An arrangement of
levers and springs moves the pointer on the dial.
Solid bodies press downwards only, but fluids equally
in all directions. The ocean of fluid air enveloping our
globe, weighing 147304, or nearly 15 Ibs. to a square inch,
is pressing on the human body with an enormous weight.
When a man lies down, he has a pressure of about
30,000 Ibs. above him, and he would be unable to get
up were it not for the fact that an equal pressure is
exerted in all directions, inside as well as outside the
56 WATER: ITS ORIGIN AND USE
whole body. For this reason the weight or pressure is not
apparent.
It is from the same cause, viz. equal pressure inside
and out, that the delicate soap-bubble withstands this
pressure, rising in the air through being filled with
slightly lighter air from the lungs.
I once saw a photograph of a simple object lesson on
the pressure of the atmosphere.
An ordinary china hot-water plate had been partly
filled with boiling water and then corked tightly. As the
water cooled and the steam condensed, a partial vacuum
was formed ; the dish could not withstand the pressure of
15 Ibs. to the square inch, and the plate was forced in
with a crash.
At sea-level, with the barometer at 30 inches, the
pressure would be 147 Ibs. per square inch (generally
spoken of as 15 Ibs. to the square inch), therefore a column
of air 1 inch square, 45 miles high, weighs 15 Ibs. Seven
miles above the surface of the earth the air is 4 times
lighter than on the ground. Fourteen miles above the
earth it is 16 times lighter. Twenty-one miles above the
. earth it is 64 times lighter.
The pressure of the atmosphere at sea-level is used as
the unit of pressure, and is called an atmosphere ; 29'905
inches of the mercurial column at 32 F. (London).
The capital of our country is here given for a definite
reason. This unit of pressure is not universal ; the unequal
distribution of land and water influences the figure, which
varies from 30'400 inches in the centre of Asia to 29'304
inches on the coast of Iceland.
The time of day, seasons, and many other considerations
also influence the pressure and upset its uniformity.
At 18,000 feet above the sea-level, under the same
conditions, the pressure would only be half the above.
PRESSURE OF ATMOSPHERE 57
A fall of 1 inch of mercury (30 to 29) shows an
increase in altitude of 910 feet; but it is not at this ratio
throughout, as the pressure is lighter in a cumulative
degree as we ascend. Were it not so, the pressure at 16
inches would be 30 to 16 = 14x910 = 12,740 feet altitude.
This is not correct, and it is in reality 16,000 feet, the
proportion increasing with the height.
The following table will show the decrease of pressure,
with the corresponding altitude, when the barometer
marks 30 inches at sea-level (air of average temperature
and dampness).
Altitude in feet. Pressure in inches.
30
910 29
1,850 28
2,820 27
3,820 26
4,850 25
5,910 24
7,010 23
8,150 22
9,330 21
10,550 20
13,170 18
16,000 16
Were the ratio of 1 inch to 910 feet of air preserved
all the way up, we should reach the limit of our
atmosphere at about 5 miles.
By a glance at this table, the difficulty to be encountered
in cooking at high altitudes will at once be apparent, the
degree of heat necessary for this purpose not being
obtainable in these heights with the ordinary utensils.
Darwin, in his Voyage of the Beagle, tells an amusing
anecdote of an occurrence which happened to his party
while crossing the Andes in 1835.
They had attained so great an altitude, and the boiling
58 WATER: ITS ORIGIN AND USE
point was, as we have seen, so low, that "our potatoes
after remaining some hours in the boiling water, were
nearly as hard as ever. The pot was left on the fire all
night, and the next morning it was boiled again ; but yet
the potatoes were not cooked.
" I found out this by overhearing my two companions
discussing the cause. They had come to the simple con-
clusion that the potatoes were bewitched, or that the pot,
which was a new one, did not choose to boil them."
It is possible to tell the altitude by boiling water.
If the temperature of the vapour of boiling water and
of air be taken at a lower and higher station, and the
difference noted and reference made to tables provided for
the purpose, the difference in the altitude between the
two stations can be correctly obtained.
To give some idea of this reduction of boiling points :
At 500 ft. below sea-level, boiling point is 213" F.
1,013 214
sea-level, 212
509 ft. above sea-level, 211*
1,021 210
5,185 202
10,053 193
From these figures we also see that, if we go down into
a mine below sea-level, a greater degree of heat is
necessary before water will boil.
Contamination and Purification of Atmosphere
All animals, including man, consume oxygen, and in
respiration exhale carbonic acid. The latter is not
allowed to accumulate, for, by the wonderful provision of
nature, it is arranged that the trees and vegetation should
feed on it ; they remove the carbon it contains, building
CONTAMINATION OF ATMOSPHERE 59
it into their structures, and setting free again the oxygen
which was united with it in the gas.
Charles Kingsley, in writing on this subject, refers to a
sickly geranium in the window of a slum cottage where
death had been rampant among the children through
vitiated air : " It spreads its blanched leaves against the
cellar panes, and peers up, as if imploringly, to the narrow
slip of sunlight at the top of the narrow alley," and he
tells how the little geranium did its best, like a heaven-
sent angel, to right the wrong which man's ignorance had
begotten, and drank in, day by day, the poisoned atmo-
sphere, forming it into fair green leaves, and breathing
into the children's faces, whenever they bent over it, the
life-giving oxygen for which their festered lungs were
craving in vain.
There are air-plants (Epiphytes) found in the damp
tropical forests of Africa, Asia, and America, which live
entirely on the nutriment obtained from the atmosphere.
" What is fraught with health," says Hugh Miller, " to
the existence of the vegetable kingdom, is in many in-
stances a deadly poison to those of the animal.
" The grasses and water-lilies of the neighbourhood of
Naples flourish luxuriantly amid the carbonic acid gas
which rests so densely over the pools and runnels out of
which they spring, that the bird stoops to drink and falls
dead into the water the two kingdoms exist under laws
of life and death so essentially dissimilar."
Man exhales 16 cubic feet of carbonic acid gas per day
when at rest, and correspondingly more in proportion to
the amount of work performed, up to about 30 cubic feet.
One ordinary gas-burner consuming 5 feet per hour
contaminates the atmosphere at the same rate as five men
by respiration, producing about an equal amount of carbon
dioxide per hour.
60 WATER: ITS ORIGIN AND USE
Winds also remove the vitiated air from the towns,
replacing it continually by purer air. The sea is also
acting in a similar capacity, churning, washing, and
cleansing the air by its waves and breakers. The benefits
to be derived from breathing such air around our coasts
has no doubt been experienced by us all ; its invigorating
effect on the human system is one of nature's greatest
physicians, and succeeds when man's ingenuity has failed
to restore health.
There is food for thought in the wholesale manner in
which we contaminate the atmosphere by pouring soot and
smoke into it from our chimneys and factory shafts. To
some extent of course this is necessary to the conditions
of our life ; but it is out of all proportion to what it would
be if our furnaces consumed the fuel properly. Let us see
what soot is. Most persons would describe it, and in general
correctly, as " unburnt carbon." But this reply would be
inadequate for Manchester, which possesses a fatty descrip-
tion of soot, quite peculiar to this town. Professor E.
Knecht has found it to comprise 50 per cent, of substances
that are not carbon. "Among them were snow-white
samples of ammonium chloride, ammonium sulphate,
calcium sulphate, and a beautifully crystallised paraffin
hydrocarbon, similar in properties to one that exists in
beeswax. The amount of heavy hydrocarbon oils in
household soot was found to be no less than 13 per cent."
From these strange components that float in the breathing
mixture sometimes called fresh air the Professor manu-
factured a dye-stuff, which was capable of producing
absolutely fast shades of brown on cotton. Professor
Knecht is of the opinion that unless more efficient fire-
grates are made compulsory, we must continue to breathe
our soot-and-air mixture.
Contamination of atmosphere by the combustion of coal
VELOCITY AND IMPULSE 61
in private houses is much greater than that of the smoking
chimneys of manufacturing and business premises. It is
estimated, says a correspondent of the Daily Telegraph
" that half to 75 per cent, of the smoke in London comes
from this source." As indicating the great amount of smoke
discharged from domestic chimneys, it has been noticed that
some of the densest London fogs have arisen on days when
the great bulk of business premises have been closed, and a
massive bank of smoke in London has been seen to rise to
a height of at least 3000 feet or 4000 feet and to be carried
by the wind in a sunlight-obscuring trail to a distance of
50 miles. Dr W. N. Shaw, of the Meteorological Office,
states that he found from comparison of records that,
owing to its smoke, London loses half of the sunshine in
winter and one-sixth in summer, and there can be no doubt
that domestic grates contribute largely towards the evil.
If the lungs of a Londoner be examined (after death),
they will be found to be of a greenish black, while those
of a countryman are fresh pink and quite clean, although
the respiratory organs of the former may not be seriously
impaired.
At the earlier period of the earth's history (the car-
boniferous), the amount of carbonic acid in the atmo-
sphere is supposed to have been much greater, thus causing
the luxuriant growth of vegetation that went to form our
present coalfields.
Velocity and Impulse
The circulation of the atmosphere called wind is in no
small degree due to the vapour it contains. The heat given
out in the process of evaporation reappears in the process
of condensation of vapour into cloud or rain ; the saturated
air, being lighter than dry air, ascends, giving rise to
aerial movements.
62
WATER: ITS ORIGIN AND USE
" If one portion of the universe," says Professor Tyndall,
" be hotter than another, a flux instantly sets in to equalise
the temperatures, while winds blow and rivers roll in
search of a stable equilibrium."
The visible effect of the work of the atmosphere on the
geological formation of our globe is not at first sight very
apparent ; it is, however, a mighty agent so mighty as to
be beyond our conception.
When moving rapidly, it agitates the sea; sets in
motion the mighty waves, with all their attendant works
of destruction, transportation, and reconstruction.
Were it not for the fact that the air surrounding us
travels with us (1000 miles per hour at the equator),
the enormous velocity of the earth's rotation would be
apparent to an alarming extent. The gently falling snow-
flakes would appear to (and really would under those con-
ditions) fly past us with a velocity of several times that
of the greatest tornado ever experienced.
To find the direct impulse of the wind in pounds on
one square foot, square the velocity in statute miles per
hour x '005016, or square the velocity in knots per hour
X -006667.
Velocity,
Pressure,
miles per hour.
Ibs. sq. ft.
3
045
Light air.
5
125
Light wind.
7
246
Light breeze.
9
406
Moderate breeze.
14
983
Fresh breeze.
20
2-00
Strong breeze.
24
2-89
Moderate gale.
30
4-51
Fresh gale.
36
6-50
Strong gale.
40
8-02
Heavy gale.
50
12-5
Storm.
100
50-2
Hurricane,
STELLAR SPACE 63
This last velocity is 12 in the Beaufort scale. It is a
familiar joke, says Dr Mill, that force 12, the maximum
of the scale, can only be recorded when observer and
observatory have both been blown away !
Stellar Space
Two short words, certainly ; but what a mystery they
imply ! How little we know of it ! It can only be compared
with time, having no end ; both go on and on, ad infinitiim.
It forms the blue vault or heavens, covering us like a
mighty dome ; and it contains our solar system, in which
the sun, the earth, the moon, the stars move, everything
moves, nothing stands still.
It is in this space that our earth is so marvellously
suspended, in which it revolves on its axis, and the
marvellous envelope of air with it ; and we are practically
unaware that we are being whirled round at the rate of
17 miles per minute ; and in addition there is the velocity
in orbit of 1100 miles per minute.
It is through this space that we receive our light and
heat, and without the latter there would be no water to
write about.
Outside the limits of our known universe are the stars,
which Carlyle calls the " street lamps of the city of God."
The self-luminous, apparently small, bright objects of
the heavens, are suns similar to our sun ; probably each
is the centre of a solar system like our own. Their size,
owing to their distance, cannot be calculated, as in the case
of the planets of our system ; the nearest fixed star being
that of a Centauri (a double star), one of the brightest
in the southern hemisphere, is 20 billions of miles distant ;
its light would take 3J years to reach us. Dr Gill gives
this period as 4 years and 4 months, and its distance from
64 WATER: ITS ORIGIN AND USE
the earth 275,000 times that of the sun. There is little
cause for wonder that David should contemplate them
and remark : " When I consider the heavens, the work
of thy fingers, the moon and the stars, which thou hast
ordained ; what is man, that thou art mindful of him ? and
the son of man, that thou so regardest him ? "
The stars visible to the eye are beyond numbering
correctly, and the telescope reveals thousands more ; then
there are the myriads beyond its reach, beyond our
comprehension.
Chambers, in the Story of the Stars, tells us that Sir
William Herschel saw through his stationary telescope
258,000 stars pass before his view in 41 minutes, and
that 20,000,000 stars are within the range of an 18-inch
reflector.
" From star to star, from kindred sphere to sphere,
From system on to system without end."
Such wonders as these should surely raise our thoughts
to the great Controller of the universe, for the Creator
is greater than His works.
J. C. Sharp, LL.D., says: "Nature and her works
are employed by Scripture aa a proof of the goodness of
God. When, therefore, in the light of these thoughts,
we study nature, we may well feel that we are engaged
in no trivial employment. Even the most common
acts of minutely observing nature's handiwork may in
this way partake of a religious character, and become,
as it were, the steps of a stair ascending towards the
Eternal."
However anxious one may be to keep rigidly to the
scientific and practical side only of these things, the
higher and religious connection between them will force
itself upon one. An apology or excuse for this is unneces-
sary, for, as the Rev. Robert Harley, F.R.A.S., remarks :
STELLAR SPACE 65
" Science without devotion is defective ; science without
religion is a corpse ; religion without science is a ghost."
The temperature of stellar space is hardly within the
scope of our study, but a few remarks on this subject
cannot fail to be of interest. It is variously estimated
as 90 F. below zero, or 122 below freezing point, and
60 F. below zero. These figures differ considerably ;
but of this we are certain it is colder than any tempera-
ture experienced on any part of the earth. In the upper
atmosphere, as we have seen, 122 F. has been recorded,
so there is reason to suppose that stellar space is even
colder than this.
Compare these figures with the mean temperature at
the Poles, which is below 13 zero F., and we shall be
able to form some vague idea of the awful cold of stellar
space. It is through 93,000,000 miles of this intensely
cold space that the sun's rays travel to reach us and
dispense their generous warmth.
CHAPTER III
CLOUDS
" The clouds may stoop from heaven and take the shape
With fold to fold of mountain or of cape."
TENNYSON.
CLOUDS consist of visible vapour or watery particles
suspended in the atmosphere. They differ only from fogs
by their height, and less degree of transparency.
How Formed
In hot weather moisture is quickly taken up, and con-
verted into vapour. The drier the air the greater the
amount of cloud or moisture that can be dissolved.
Clouds, when first formed, contain more moisture than
the air is able to maintain in an invisible state. As the
cloud gradually mixes with a larger mass of air, it is more
and more dissolved, finally passing altogether from the
condition of finely divided liquid into transparent vapour.
This process will be more easily understood by compar-
ing it with breathing. The moisture from the lungs on a
fine, dry, warm day is invisible ; on a cold, damp day little
clouds of aqueous vapour appear to issue from the mouth,
gradually dispersing as they mix with the surrounding air.
Nature but elaborates on this simple process, and we
have moisture transformed into vapour, clouds, condensa-
tion, rain ; then the streams and rivers, and at last the
boundless ocean.
66
HOW FORMED 67
So clouds, like fog and mist, are produced by the
partial condensation of vapour in the higher regions of
the atmosphere.
How do these watery vapours rise to such heights to
form the clouds ? The reason has already been given and
the cause explained : watery vapour is lighter than air.
The minute globules of water which compose a cloud,
which is the middle stage between vapour and rain, are
only about 30^ f an ^ ncn ^ n diameter, and have been
expressively called by Professor Tyndall " water dust."
They were at one time supposed to be hollow, and for
this reason able to float in the air ; but the secret of their
suspension lies in their minuteness. The slightest upward
motion of the air will keep them suspended, as we see
them, for a considerable time.
The particles grow by the adhesion of fresh coatings of
water as the condensation continues, and the larger ones
fall and absorb the smaller particles, increasing in size to,
say, one-twentieth to one-tenth of an inch in diameter,
when they can no longer remain suspended.
From whence does all this vapour arise ? The sunbeams
falling upon the sea warm it, though not so much as the
land, sending up aqueous vapour; thus both from land
and sea we have ascending currents of vapour which are
eventually formed into clouds.
Hartwig says: " In every zone evaporation is constantly
active ; but the chief seat of its powers is in the equatorial
regions, where the vertical rays of the sun plunge day
after day into the bosom of the ocean and perpetually
saturate the burning air."
These currents, on reaching a certain elevation, divide
and flow part towards the north and part towards the
south.
Colder air flows in to take their place. Circulation is
68 WATER: ITS ORIGIN AND USE
thus established, and the air, laden with vapour, commences
to form into cloud, and condenses, falling as rain or snow.
Cloud-banner
A cloud-banner is sometimes seen flying from a mountain
top. The streamer of cloud appears to be steady, though a
strong wind may be blowing; but it is only apparently
permanent ; its extremity is continually being dissolved by
the atmosphere, the other end being incessantly renewed by
partial condensation at the peak. The cloud-banner of
the Matterhorn is described by Professor Tyndall in the
following words : " The Matterhorn 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 lee of it a cloud
which appeared to cling tenaciously to the rocks. In
reality, however, there was no clinging ; the condensed
vapour incessantly got away, but it was ever renewed, and
thus a river of cloud had been sent from the mountain.
The wind, charged with moisture, rubbed against the cold
cone of the Matterhorn ; the vapour was chilled and pre-
cipitated in his lee. The summit seemed to smoke some-
times 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."
Moisture in Clouds
" There, floating in the blue expanse,
The watery clouds we view,
Whence fruitful showers, at His command,
The thirsty soil bedew."
From the Latin.
When we see clouds, whether high or low, in the air, we
are looking at nature's process of preparing rain for the
Mrs Aubrey Le niond.
THE CLOUD-BANNER OF THE MATTERHORN.
[ To face p. 68.
RE-EVAPORATION 69
earth first invisible vapour, cloud, rain ; then, at 32, snow
and hail. Even at this temperature the air will gather
moisture by evaporation. A cubic foot of air at zero F.
will hold \ grain of vapour ; at 60 F., 5 grains. At 80 F.
11 grains will remain invisible in the space of a cubic foot.
It has often been remarked, " I wonder what it is like
to be in the clouds." Probably all of us have experienced
it ; for it is not necessary to ascend in a balloon to satisfy
a wish in that direction. It is not a pleasant experience.
When condensation occurs near the surface of the earth,
we get clouds, but we call it fog, and dislike it accord-
ingly. There is little difference between fog, mist, and
cloud, except the place of origin.
We can at times climb above the clouds in our own
country ; even our hills under certain atmospheric con-
ditions make this possible. It is an experience not easily
forgotten, to climb for a considerable time through a
drenching mist, and at last to come, dripping wet, through
the clouds into clear, bright sunshine. Here nothing meets
the eye but an endless sea of clouds, rolling like waves,
breaking round the peaks and rolling round their massive
sides, as their more substantial prototype, the ocean, rolls
around our coasts ; and we see, above, the blue dome of
heaven, the vast expanse of clouds and space.
Re-evaporation
Sometimes condensation occurs among the clouds, rain
falling from an upper stratum, but not reaching the
ground, for on coming into a warmer temperature it is re-
evaporated on its downward journey.
" A little gale will soon disperse that cloud
And blow it to the source from whence it came ;
The very beams will dry those vapours up."
SHAKESPEARK.
70 WATER: ITS ORIGIN AND USE
The writer has frequently watched an isolated mass of
noble white cumulus cloud in a clear sky, as it slowly
sails across the blue heavens, like a snow-clad mountain,
and has seen it slowly evaporate and almost disappear,
leaving but a few stray filaments to guide the eye to its
actual position ; then slowly condense, become visible
again, but altered in form to that of a frothy sea, or
indescribable feathery moving mass of exquisite beauty.
It slowly changes into the most beautiful forms, disappears
and reappears in another shape unceasingly, never retain-
ing the same density or form for any length of time. It
is a marvellous and inspiring sight.
Professor Tyndall refers to condensation and evapora-
tion of cloud as seen in the Alps :
" As the sun sank the shadow of the Finsteraarhorn 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 Khone. 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, when
condensation was equal to the supply."
Those in our crowded cities whose gardens and yards
are so small as to be scarcely worthy of either name, can,
under certain atmospheric conditions, obtain most restful
and interesting views in the heavens above by watching
the form, speed, and colour of the clouds: a sight that
few of us ever contemplate, unless in a critical, grumbling
mood, caring only whether they foretell rain and its
consequent inconvenience to our anticipated work or
pleasure.
Mrs Aubrey Le Blond.
SEA OF CLOUD OVER THE LAKE OF ST MORITZ WHILE FREEZING
(THE ENGADINE, SWITZERLAND).
A CLOUD STUDY, ENGADINE.
Mrs Aubrey Le Blond.
[To face p. 70.
DEW-POINT 71
Clouds were of course designed by the Creator primarily
for rain, but surely also for man's pleasure; for all the
beauties of nature must be considered as gifts to man for
his enjoyment and study, which, if we will only take
delight in them, will lift us above the everyday troubles
that come to all at all times.
Dew-point
When air is warm and moist, a slight lowering of
temperature produces condensation, and clouds are formed.
The ordinary expression " dampness " does not therefore
give a comparative idea of the amount of vapour present
in the air ; for warm air may hold more vapour and yet
feel drier. The degree of humidity is determined by the
nearness of the dew-point to the existing temperature,
and is governed by the amount of moisture present, and
the temperature of the air in which it is dissolved.
As the air becomes cooler and cooler, it can contain less
and less vapour. When it can hold no more it is said to
be saturated, and the temperature then reached is called
the dew-point.
Forms of Clouds
There are three primary forms of clouds stratus,
cumulus, and cirrus. They are usually seen in the same
relative altitudes low, intermediate, and high.
These primary forms of clouds are subdivided into cirro-
cumulus, cirro-stratus, cumulo-stratus, nimbus, cumulo-
cirrus-stratus, or rain-cloud. The last is the least attractive-
looking, but it is only when the dark surface of this cloud
forms its background that the splendid phenomenon of
the rainbow is exhibited in perfection.
72 WATER: ITS ORIGIN AND USE
Altitude and Velocity
The average height of cloud is greater in summer than
in winter. This fact calls to mind the well-known lines of
Lord Tennyson :
" It was the time when lilies blow
And clouds are highest up in air."
From a series of observations near Skiddaw, it was
found that clouds were generally above 3000 feet; only
ten times in five years were they below 300 feet from the
ground.
Of all clouds, cirrus has the least density, greatest
elevation, and the greatest variety of figure.
Clouds travel more slowly in summer than in winter.
From observations made at Blue Hill Observatory,
Boston, U.S.A., the following interesting particulars were
obtained :
Description of Height in Average velocity,
cloud. feet. miles per hour.
Stratus. .' ; ';''' si -i 1,676 19
Cumulus :* uilii'irts 5,326 24
Alto-cumulus . .12,724 34
Cirro-cumulus . . 21,888 71
Cirrus .... 29,317 78
In winter the velocity of the wind is twice as great at
the upper levels as in summer. At this period cirrus
clouds have been known to travel at the rate of 96 miles
per hour.
The upper half of the air, above 16,000 feet, is calculated
to possess six times the energy of the lower half. Of this
latter we utilise but little ; only the merest strip or layer.
The whole of the remainder is wasted.
The enormous force provided by nature is now employed
to a much smaller extent than in former years. Sailing
Mrs Aubrey Le Blond.
ABOVE A SEA OF CLOUD, ARCTIC NORWAY.
Mm Aubrey Le Blond.
CLOUDS BREAKING LIKE A GIANT WATERFALL OVER THE
FURGGEN RIDGE, MATTERHORN.
[To face p. 72.
ALTITUDE AND VELOCITY 73
vessels and the once familiar windmills have been practi-
cally supplanted by steam.
The force and velocity of the wind is measured by
an instrument called the anemometer, from the Greek
anemos, wind ; metron, measure.
The enormous speed attained by the air in a tornado
has been stated at 500 miles per hour. This is, however,
an exaggeration.
The pressure exerted by the wind on all that stands in
its way varies according to its velocity.
The circulation of the atmosphere, which we call wind,
is a current of air induced first by the heat of the sun,
which expands the air and causes it to rise, its place being
taken by the cooler and heavier air, and, in the next place,
by the rotation of the earth.
The winds have been divided in to fixed or constant, as trade
winds ; periodical, as monsoons, etc. ; and variable winds.
Trade winds, so called, are perpetual or constant winds
which occur in all open seas on both sides of the equator,
their origin being the great heat of the torrid zone, which
causes the air to rise to high regions, and the colder air
from north and south flows in to take its place.
Calms, so called, are the tracts in the Atlantic and
Pacific Oceans between the trade winds, where long
periods of calm prevail.
Hartwig calls this " the dreaded zone of the equatorial
calms, where long calms alternate with dreadful storms,
and the sultry air weighs heavily upon the spirits " ; and
it was in this region that the phantom ship of the Ancient
Mariner lay becalmed :
" Day after day, day after day
We stuck, nor breath nor motion,
As idle as a painted ship
Upon a painted ocean."
74 WATER : ITS ORIGIN AND USE
Etesian winds, which blow during the summer in the
Mediterranean, towards North Africa, take the place of
the heated air which rises from the Sahara and other
African deserts.
Egypt owes a great part of its fertility to these winds,
carrying, as they do, the vapours of the Mediterranean
across that country to the Abyssinian Mountains, where
they are condensed in torrential rains, flooding the Nile,
and so producing fertility where otherwise sterility and
arid wastes only would be found.
The simoom, a hot, suffocating wind that blows occasion-
ally in Africa and Arabia, is generated by the extreme
heat of the deserts. The air, heated by contact with these
burning sands, ascends, and the colder air rushes in, forming
a whirlwind which carries with it clouds of dust. The
sirocco of South Italy and the kamsin in Egypt and Syria
are similar to the simoom :
" The red-hot breath of the most lone simoom,
Which dwells but in the desert, and sweeps o'er
The barren sands, which bear no shrubs to blast,
And revels o'er their wild and arid waves.
BYKON.
Harmattan a hot, dry wind, which, coming from the
interior of Africa, prevails at times on the coast of Guinea
in December, January, and February, withers and destroys
vegetation.
Mistral violent, cold north-east winds experienced in
autumn, winter, and spring in Provence and the neighbour-
ing districts on the borders of the Mediterranean.
Monsoon is the name given to a certain disturbance
of the regular course of the trade winds in the Arabian
and Indian Seas, or similar alternating winds in any
region.
Typhoon a violent hurricane experienced on the coasts
H.M.S. "PHCENIX" DRIVEN ASHORE OFF KOWLOON.
WRECKED BY THE TYPHOON, KOWLOON.
[To face p. 74.
COLOUR OF CLOUDS 75
of China and Japan and in the Archipelago. It is most
frequent and disastrous in July, August, and September.
" So wrecked the tempest, as the sea
Engulfs a vessel, grasp' d a tree,
Wrench'd from wide-spreading roots, and laid
The giant on the hillside dead ;
So rushed the torrent, small at first,
Then, gathering strength in moving, burst
In deluge streams of rain and snow
Upon the hills and plains below.
So wreck'd the wind, so swept the rain
Of that tornado hurricane."
Whirlwinds are caused by the meeting of violent winds,
moving in opposite directions, and setting up a whirling
spiral motion in the atmosphere.
On land they carry dust and sand with them, lifting it
up and scattering it broadcast. At sea they give rise to
waterspouts. They are most frequent and violent in
tropical climates.
Colour of Clouds
SUNSET
" Those evening clouds, that setting ray,
And beauteous tints serve to display
Their great Creator's praise ;
Then let the short-lived thing called man,
Whose life's comprised within a span,
To Him his homage raise.
We often praise the evening clouds,
And tints so gay and bold,
But seldom think upon our God,
Who tinged these clouds with gold."
SCOTT.
The colour of clouds is most apparent when the sun is
near the horizon ; its rays falling on the watery vapours
produce the glorious tints of sunrise and sunset, which
tints may be used as a guide in forecasting the changes in
the weather that may be expected to follow.
76 WATER : ITS ORIGIN AND TJSE
The quantity and condition of the watery vapour have
great influence in the production of the hues. The red
rays are caused by having to pass through about 900 miles
of atmosphere, instead of 50 miles when the sun is over-
head. The blue rays are absorbed first, the yellow rays
next ; the red rays have the greatest penetrating power,
and therefore reach us most readily. It is owing to the
enormous depth of the atmosphere which the light from
bodies on the horizon has to penetrate that no star is ever
visible there.
I recollect vividly the glorious dawn of the last day of
the year 1905. It was, without doubt, the most gorgeous
spectacle I have ever seen ; for if ever " the heavens de-
clared the glory of God, and the firmament showed his
handiwork," it was this last Sabbath morn of the year.
It was a little past 6 A.M., two hours before sunrise,
when the eastern horizon became brightly illuminated.
Though of intense brightness, it was not the angry red
betokening a wet and cheerless day. Presently the whole
sky became coloured with what I can only compare to an
ocean of golden brightness, and every separate wave had a
crest of a still brighter hue ; even on the extreme western
horizon, where it disappeared in a space of purest blue,
the rose-pink reflection of the still hidden sun was
strongly apparent.
It called to my mind the well-known words of Bishop
Heber :
" Till, like a sea of glory,
It spreads from pole to pole."
This canopy of golden waves was to be seen until about
8 A.M., giving two hours for the enjoyment of this
sublime spectacle. Truly the old year left us with a grace-
ful grandeur.
At last the sun appeared above the horizon, and
DUST PARTICLES IN CLOUDS 77
slowly the light of day dispersed those lovely tints,
melting them into every conceivable shade of red, blue,
and violet, leaving us a bright, crisp, clear day with which
to close the year.
Dust Particles in Clouds
Dust particles, suspended in the atmosphere by the
small globules of watery vapour, assist greatly in the
glorious effects I have just described.
The dust ejected by the eruption of Krakatoa in 1883
was sufficient to spread a mantle of particles in the air
over the whole world, causing beautiful and phenomenal
skies, which often lasted 1 hours after sunset; a huge
corona, of all the colours of the spectrum in turn, was also
observed round the sun.
These beautiful colours are always present more or less,
and are due to the diffraction by suspended particles of
water; but the dust from Krakatoa intensified and pro-
longed these effects all over the world.
These particles remained suspended for a long time :
some years elapsed before they all settled and our skies
resumed their usual appearance.
One of the most gorgeous spectacles the eye can rest on
is a sunset at sea, where sky and sea are illuminated with
every imaginable tint, and
" The sea is but another sky,
The sky a sea as well,
And which is earth and which is heaven,
The eye can scarcely tell."
LONQFBLLOW,
CHAPTEK IV
RAIN
Cause of Rain
"At last
The clouds consign their treasures to the fields,
And softly shaking on the dimpled pool
Prelusive drops, let all their moisture flow
In large effusion o'er the freshened world."
EAIN, the water that falls from the heavens, is the final stage
of the condensation of the vapour in the air. In the process
of condensation the small particles of water gradually
grow larger and larger, until their size prevents them from
being suspended any longer, and they fall as rain.
We have seen the process by which liquids and solids
assume the gaseous state. The rate at which the evapora-
tion of the same takes place is controlled by the tempera-
ture of the liquid or solid, the extent of its exposed surface,
and the condition of the atmosphere ; and by means of the
latter facility is given to the gaseous particles to escape.
The atmosphere will continue to absorb the particles of
vapour until it is fully saturated, when, if the temperature
remains the same, evaporation will be arrested, there being
no further opportunity for the vapour to escape.
Thus, at a temperature of 50 F., evaporation goes on
until the vapour pressure reaches 0'361 inches. If the
temperature be raised to 60 F. ; evaporation will be re-
sumed until the vapour pressure rises to 0-518 inches, and
so on in proportion to the temperature. If the tempera-
78
CAUSE OF RAIN 79
ture were to fall from 60 F. back to 50 F., the air would
not retain the whole aqueous vapour ; the surplus would
condense and fall as rain, until the previous condition
(50 F., 0'361 inches) were attained, and, with the forma-
tion of the rain, the air would yield up the latent heat
contained in the vapour so condensed.
If the reduced temperature be caused by the introduc-
tion of a cold solid body, the condensation will take place
in the layer of air next that body, forming dew upon its
surface, and if it is sufficiently cold it will run with water.
We have all seen this simple object lesson. If on a
hot summer day a bottle of cold water be brought into
the room, it quickly becomes covered with drops of
moisture, which eventually trickle down its sides.
Some might imagine that this water came from the
inside of the bottle ; but it is simply the action of the cold
bottle cooling the warm air which is in immediate contact
with it, so that it cannot retain the moisture invisibly, and
deposits it on the side of the bottle. If the bottle were not
colder than the atmosphere in the room, this depositing of
the moisture would not occur.
The moisture on the window-pane which makes the
pretty frost pictures is another instance the exterior
cold on the glass condenses the atmosphere in the room.
This is the manner in which nature forms dew, rain,
hail, snow, and all atmospherical precipitation ; it is the
natural result of any refrigerating influence on the air.
When warm air-currents are transported to colder
regions, the moisture condenses into small globules, but
little heavier than the atmosphere, forming cloud ; if the
condensation be continued, rain results. Those upward
currents, therefore, carrying away the heat, which at
times, especially in the tropics, would be insupportable,
render hot climates habitable.
80 WATER: ITS ORIGIN AND USE
Rain does not always of necessity fall from clouds. If the
invisible vapour of the atmosphere suddenly comes into con-
tact with cold air, the vapour passes immediately into rain.
It is in this manner that mountains receive more rain
than plains. The atmosphere strikes the sides of the
mountain and is quickly carried up into higher regions and
rapidly condensed.
" The cold crags," says Tyndall, " 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 ascending,
and the clouds were slowly lifted above the tallest peaks,
where they arranged themselves in fantastic forms as they
gradually melted away."
Dr Shaw, Director of the Meteorological Office, states
that there is a remarkable parallelism between the winds
of St Helena and our rainfall, and that any excess or defi-
ciency of the wind velocity is often followed by a similar
excess or shortage in our rainfall in the succeeding month.
The size of the rain-drops depends upon the thickness,
density, and elevation of the clouds out of which they are
condensed. Minute particles of vapour composing the
clouds increase in number as the temperature decreases,
and begin to fall. The largest fall fastest, and in their
descent unite with the smaller ones they encounter, and
thus increase their size :
"But, lo ! while I listened, down heavily dropt
A few tears from a low-sailing cloud ;
Large and few they descended ; then thickened ; then stopt ;
Then poured down abundantly loud.
Oh ! the rapture of beauty, of sweetness of sound,
That succeeded that soft gracious rain !
With laughter and singing the valley rang round
And the little hills shouted again."
CAROLINE SOUTHEY.
TIME OF GREATEST FALL 81
Time of Greatest Fall
" Thou comest, Autumn, heralded by rain." LONGFELLOW.
The heaviest rainfall is in the autumn throughout the
greater part of England. More rain falls by night than
by day. The cold at night condenses and cools the air,
thus diminishing its capacity for retaining moisture.
Seathwaite, a village of Borrowdale, Cumberland, is in
almost the wettest spot of the British Isles, the average
yearly rainfall being about 1 37 inches. On several occasions
the daily fall has exceeded 6 inches ; and on one occasion 8
inches were reached. Dr Mill's results seem to show that
" the rainfall at Seathwaite in an average year indicates a
tendency to be greater during the hours of darkness than
in daylight ; that rather less than half the time during
which rain is falling it continues without intermission for
at least six hours at a time ; and that rather more than
half the total amount of rain is deposited in such long
showers."
Accumulated evidence seems to point to the fact that
the atmosphere of the world is getting drier.
There is universally a continuous deficiency of rainfall.
The ice-cap of the South Pole was found by Captain Scott
to be retreating. He states that the Ferrar Glacier was
at one time, called the ancient high-tide mark, 3000 to
4000 feet above its present level in places. The inland
ice-sheet also stood above its present level, probably to
the extent of 400 or 500 feet.
The edge of the great ice-barrier was, only sixty years
ago, 20 or 30 miles in advance of its present position.
In the Antarctic, when the glaciation was at its maxi-
mum, the glacier valleys were then overflowing, pouring
vast masses of ice into the sea. Granite boulders (erratics)
and morainic terraces on the slopes of Terror, 800 feet
6
82 WATER : ITS ORIGIN AND USE
above the present barrier surface, point to great diminu-
tion of ice in these regions.
The glaciers of the whole world are also retreating, and
are but remnants of their former selves. All this points
to the presence of less moisture in the atmosphere. (See
Glaciers.)
There is also reason to believe that the great desert
regions of Australia, South Africa, Asia, America, and the
great Sahara are extending from the same cause, as also
the Steppes of Russia.
The growing desiccation of large portions of the earth's
surface causes great famines, as in India, Eussia, etc.
Where this was a small and occasional visitation, it is now
a serious and frequent occurrence.
From the same cause the Caspian Sea is becoming
salter and smaller, as are many other lakes, now receiving
a diminishe^ quantity of rainfall in the form of springs,
streams, and rivers.
Absorption and Percolation, etc.
When rain falls, according to the quantity, the season
in which it falls, and certain atmospheric conditions, it
does many things.
Some evaporates ; some is absorbed by vegetation. The
remainder, after saturating the surface, runs off, forming
rivulets and streams, conveying with it the soil over
which it passes.
The part rain plays in connection with vegetable life is
apparent even to those who pay no heed to nature's work.
It may, however, not be irrelevant to call attention to the
fact that, but for the water, the food properties in the
soil, consisting principally of potash, soda, lime, magnesia,
etc., could not be absorbed by vegetable life, as they are in
ABSORPTION AND PERCOLATION, ETC. 83
a solid state, and cannot be assimilated by the plants until
they have been dissolved by water.
Charles Kingsley says : " It is wonderful or should
have been in our eyes, that a shower of rain should make
the grass grow, and that the grass should become flesh,
and the flesh food for the thinking brain of man."
Evaporation is subject to great variation, being in-
fluenced by climatic conditions, locality, etc.
In temperate climates, during the summer months,
water exposed to the sun loses by evaporation to inch
per day, or an average for the year of ^ to ^ inch per
day.
In England it is taken as being between 12 and 16
inches per year, and London 16*14 inches.
In dry weather j^ inch has been found to evaporate per
day from the large reservoir which supplies Manchester.
In India inch has evaporated in one day. At Nagpur
48 inches evaporated in 272 days of dry weather. A
typical instance was given in the Daily Telegraph, 9th
October 1906:
" New South Wales boasts of two lakes Lake George
and Lake Bathurst. The former of these is a striking
example of the activity of evaporation in the sub-tropical
climate. Normally it is a body of water 16 miles long,
and 5 broad at its widest part, and presents an area
of about 40 square miles ; but it has been known for
years together to be quite dry. This was the case from
1846 to 1850. Lake George receives the waters of several
small streams, and has no outlet, and yet the amount of
evaporation in dry seasons exceeds the inflow. On a
small scale this repeats the experience of the Caspian and
the Dead Sea. The Caspian Sea is as large as France.
The waters of the Volga and the Ural River and of the
numberless streams from the Caucasus flow into it, There
84 WATER: ITS ORIGIN AND USE
is no outlet, and yet the evaporation is greater than the
supply, and the Caspian is becoming shallower and more
brackish. In no part of the world, probably, would a
body of water persist all the year round if it depended
solely on the rainfall upon its surface. In Cape Colony,
where the precipitation seldom exceeds 20 inches per
annum, the evaporation amounts to 60 inches, where there
is water to evaporate."
Vegetation also absorbs a portion of the rainfall.
The available proportion of surface rainfall depends on
the nature of the ground. Of that falling on steep surfaces
of granite and slate rocks, etc., almost 1*0 is available; on
moorland and hills, pasture land, 0'8 to 06; on flat,
cultivated country, 0'5 to 0'4 ; that falling on our Chalk
formation, O'O. Under certain conditions it may percolate
through the strata, dissolving soluble matter in its journey,
and forming springs which break out at lower levels. Or,
again, it may penetrate to the deep-seated springs, that
have for ages, unseen, poured their valuable contents
secretly into the rivers, or into the sea, forming submarine
springs. It is estimated that 0'3 to 0'4 of the total amount
of rain falling upon the Chalk formation reaches and
replenishes the deep-seated springs.
These secret recesses, bored into by man in search of
water, form one of the sources of the world's supply.
Should the rain fall on an impervious stratum, it is left
to man to turn the work of nature to his uses. He dams
up the valleys by powerful masonry, and then stores the
excess water that falls in wet seasons, which would other-
wise flow to sea and be wasted. In this way provision is
made against drought, and a continuous and copious supply
all the year round is obtained.
As rain percolates more easily in some places than
in others, it forms hollows or pipes in the chalk, which
AMOUNT OF RAIN 85
eventually get filled up with clay, gravel, and sand. These
may often be seen in the face of chalk pits and railway
cuttings.
RAIN
" How beautiful is the rain !
After the dust and heat,
In the broad and fiery street,
In the narrow lane,
How beautiful is the rain ! "
LONGFELLOW.
Amount of Rain
In order to measure the quantity of rain that falls, an
instrument called the pluveometer, or rain-gauge, is fixed
usually in some open situation. This collects the rain-
water, which is measured in inches. One inch of rain is
equal to
1 gallon falling over 2 square feet.
22,427 gallons 1 acre.
14,355,280 1 square mile.
If spread over a period of 365 days, it would yield
62 gallons per day per acre for one year.
40,000 square mile
With an annual absorption of, say, 10 inches of rainfall,
it would yield a daily volume of 400,000 gallons per
square mile.
Distribution of Rain
It has been computed that the average annual rainfall
of the globe is 33 inches. One-fourth of the land surface
receives less than 12 inches per annum ; one-fourth has
from 12 to 24 inches; one-fourth (including the British
Isles) has 24 to 48 inches; and the remaining fourth
receives over 48 inches. Of this amount of rain that falls
86
WATER : ITS ORIGIN AND USE
on the land 27 per cent, drains into the Pacific and Indian
Oceans; 22 per cent, has no outlet; 51 per cent, is tributary
to the Atlantic. The large amount of the latter is due
to the Andes and the Rocky Mountains, which drive the
whole of the rainfall of South America, and a great part of
North America, to the east.
We find in England that the annual rainfall varies from
223 inches at "The Stye," Cumberland (in 1903), to 14
inches at Shoeburyness in 1905.
In Cumberland, as well as in some parts of Scotland, 6
or 7 inches have been known to fall in 24 hours, but this
is a rare occurrence. At Glen-na-Smoel Waterworks.
Dublin, 571 inches fell on 25th August 1905.
The mean rainfall for the British Islands is 36 inches,
and for Great Britain 26 inches.
The British Eainfall Statistics for 1905 contain the
following interesting figures :
Extremes of Rainfall in 1905
ENGLAND
Greatest
Inches.
Least
The Stye (Cumberland) 171-00
Styehead Tarn . 146-30
Snowdon (Glaslyn)
(Llydaw)
Glenquoich
Ben Lomond
Gap of Dunloe .
Brandon Bay .
Shoeburyness .
Alford
WALES
176-60
147-50
Caldecot Level
Rhyl . .
SCOTLAND
114-41
111-50
Bear Hills
Leith
IRELAND
93-70 I Banagher
79-00 Athlone .
Inches.
14-57
15-05
21-50
22-24
19-12
22-18
21-52
22-30
EXTREMES OF RAINFALL IN 1905 87
At the following places the mean rainfall, taken over a
period of 40 years, works out as follows :
London 24, Manchester 36, Cardiff 43, Glasgow 39,
Cork 40, Galway 50.
When we refer to the statistics of foreign countries, we
find some exceedingly high records :
Cherra Punji (Assam) India . . .610 inches.
Coimbra, Portugal .... 224
Belize, Honduras . . . . 153
Guadaloupe Matonba, West Indies . 285
S. Luis de Maranhao, Brazil . . . 276
We often hear the remark, that the rainfall is so much
per cent, above or below the mean annual quantity. The
reader will probably ask how the mean annual rainfall is
arrived at, and what period is taken. It is found that the
average over a period of 40 years gives the minimum of
error.
From a large number of records taken all over the
world, Sir A. Binnie found the error to be less as the number
of years was increased. If the mean of 5 years be taken,
there will probably be a deviation from the true mean
annual rainfall of 14'93 per cent., above or below ; for 10
years, 8'22 per cent.; for 15 years, 475 per cent. ; for 20
years, 3-24 per cent. ; for 25 years, 2-75 per cent. ; for 30
years, 2'26 per cent.; and for 35 years, 178 per cent. ; and
for 40 years considerably less.
If the mean annual rainfall of a place be known, it is
but a simple matter to arrive at the percentage of increase
or decrease. For instance :
If the mean annual rainfall of a place is 30 inches,
which is increased for one year to 40 inches, 40 -f 30 = 1'33 ;
or, the increase being 10 inches, x = 33 per cent.
oO 1
more than the mean.
88 WATER: ITS ORIGIN AND USE
" The greatest rainfall is in the tropics. The regions of
greatest heat are the regions of greatest rainfall. This
zone of greatest moisture follows the sun across the
equator, as the sun's declination changes, and more rain
falls in the north hemisphere than in the south
hemisphere " (Chambers).
Tropical Rainfall
Although more rain falls in the tropics than in the tem-
perate zones, the number of rainy days is less, the averages
being 80 and 160 respectively.
Of Singapore and Mindoro, one of the Philippine Islands,
it may be said with Shakespeare
" With hey, ho ! the wind and the rain
Must make content with his fortunes fit,
For the rain, it raineth every day."
Professor Tyndall has given us a splendid description of
tropical rainfall. He says : " The heating of the tropical air
by the sun is indirect. The solar beams have scarcely any
power to heat the air through which they pass. They heat
the land and the ocean, and these communicate their heat
to the air in contact with them. The air and vapour start
upwards, charged with heat thus communicated, and the
heaviest rains occur at those places where the sun is
vertically overhead.
" The ascending air is chilled by expansion. This is
one source of the coldness of the higher atmospheric
regions.
"The aqueous vapour rises from the tropical ocean, with
heat to preserve the vapour as vapour: it rises, comes
into chilled regions, and is still further chilled by its own
expansion. The load of vapour is in part precipitated ;
clouds are formed; their particles coalesce to rain-drops,
TROPICAL RATNFALL 89
which descend daily in gushes, so profuse that the word
' torrential ' is used.
" Thus, long before the air from the Equator reaches the
Poles, its vapour is in a great part removed from it. Still,
a good quantity of the vapour is carried forward, which
yields hail, rain, and snow in northern and southern
lands."
It has been computed that every year the amount of
rain and snow falling on the surface of the globe would
be sufficient to fill a lake, 200,000 square miles in extent
about the size of France a mile deep. In the Khasia
Hills, Assam, 600 inches a year have been recorded, and
30 inches have been known to fall on each of five successive
days, or 150 inches in five days, which is equal to six
years' rainfall in London. This was until recently the
largest rainfall ever recorded. Here the average over a
period of 24 years is 493-19 inches. At Cherra Punji, in
Assam, in 1861 the rainfall was 805 inches, of which amount
366 inches fell in July. Here, on 12th June 1876, 40 inches
of rain fell in 24 hours. In Seoni Malwa, in the Central
Provinces of India, on 8th July 1905, 19 inches of rain fell
in 36 hours, 13 inches of which fell in the last 24 hours,
causing a record flood.
I am indebted to Dr Mill for the particulars of the
heaviest rainfall recorded in London. This was measured
on 23rd June 1878, when 3'28 inches fell between 1.32 P.M.
and 3. P.M. No rain fell between 2. 12 and 2.46 P.M., so
that the actual period of rainfall was only 58 minutes.
Other records are
London . . 3'12 ins. in 2 hours 17 minutes, 1st
Aug. 1846.
Joyeuse (France) 31 '17 22
Genoa . . 30'00 24
Bombay . 2 4 '00 ,, one night.
90 WATER : ITS ORIGIN AND USE
In the Geographical Journal a phenomenal rainfall is
reported by Mr Clement Wragge (1893) from observations
taken at Crohamhurst, on the western slope of Mont Blanc,
a peak on a spur of the D'Aguilar range, South-Eastern
Queensland (the whole district is watered by the Stanley
River, a tributary of the Brisbane Paver). The gauge was
fixed at an altitude of 1400 feet above sea-level.
24 hours ending 9 A.M., 1st February . 10-775 inches.
2nd . 20-056
3rd . 35-714
4th 10-760
Total for 4 days . 77'305
The result being floods of a disastrous description,
creating great devastation, with loss of life, and damage
estimated at 2,000,000. The world's record was, however,
the phenomenal rainfall at Suva, Fiji, on 8th August 1906,
when 41 inches fell in about 13 hours.
It has often been stated that rain-drops in tropical
climates have been as large as 1 inch in diameter. Professor
Wieser, however, asserts that he never obtained any
weighing more than 0'26 gramme, and then only from
very low clouds.
Rainless Districts
Rainless districts are few in number. In the Sahara
Desert, part of Arabia, the Desert of Gobi, and part of
Mexico, it has seldom been known to rain.
The Desert of Gobi is one of the most extensive table-
lands of the world,a rainless district of 400,000 square miles.
In certain parts of Chili and Peru no rain has fallen
for many years. In the latter case it is a most fortunate
thing, most of the houses being built with blocks of " Chili
saltpetre " or sodium nitrate, which is soluble in water.
IMPURITY OF RAIN 91
"At Copiapo (Northern Chili)," says Darwin, "there
may not be more than one shower in three years. This is
generally followed by a rainy year, the floods doing much
damage."
In the port of Iquique, on the coast of Peru, but one
light shower falls in many years, and the inhabitants obtain
water from Pisagua, 40 miles northwards. It is brought
in boats, and is sold at the rate of 4s. 6d. for an 18-gallon
cask. Darwin (12th July 1835) paid threepence for a
wine-bottleful.
Some districts, though not rainless, have but very little
rain :
Madrid, Spain . 9 inches per annum.
Socorro, New Mexico . .8
Cumana, Venezuela . . . 7|
Astrachan, Russia . . . 6
Several districts in Eussia and Siberia have as low a
record as 5*3, and even 2 inches for the year has been
recorded at Port Said.
Impurity of Rain
"Pure water is a perfectly distinct substance. The
properties of any portion, however small, of a quantity of
pure water are identical with the properties of any other
portion.
" But pure water is never found in nature. One may
even say that no man has ever seen or handled absolutely
pure water. It is an ideal substance, to which some
specimens of highly purified water have nearly approached.
" Natural waters are complicated mixtures ; but the
proportion of impurities, that is, of substances which are
not water, in some kinds of lake waters, and in the rain
that falls in places far from human habitations, is so small
92 WATER : ITS ORIGIN AND USE
that such waters may be spoken of in ordinary language
as pure " (Pattison Muir).
In addition to the water falling as rain, there is the
foreign matter, which forms no small proportion of the
benefits derived by vegetation from the rainfall.
From experiments and analysis of rain-water in the
neighbourhood of Caen (France), Mr J. J. Pierre found
that a hectare of land receives annually from the atmo-
sphere, by means of rain
Chloride of sodium . . . 37 '5 kilogrammes.
potassium . . 8-2
magnesium . . 2'5
calcium . . .1/8
Sulphate of soda . . . 8'4
potash . . .8-0
lime . . . 6'2
magnesia . . 5*9
If water of a great purity be required and rain-water is
available, it will be necessary to distil it. Even then the
first portion of the products of distillation should be
thrown away, for scarcely two-fifths of the whole can be
safely used as pure distilled water. Where very accurate
results are desired, it is a common practice in the labora-
tories to re-distil the distilled water, to make certain of
its purity.
"Hardness" of Water
When rain-water has filtered through the rocks and
soil, reappearing in the form of a spring or river, it is more
or less charged with salts from the earth, such as sea-salt,
gypsum, and chalk.
When these are present in small proportions the water
is termed soft ; when it contains larger proportions it is
said to be " hard."
DUST PARTICLES IN RAIN 93
The hardness of rain-water varies from to 10.
The latter degree was obtained near the sea-shore, at
Land's End, 100 feet above the sea, when the wind was
blowing in from the sea. In rough weather the average
hardness of rain-water may be taken to be '62.
In the purest rain-water, traces of carbonic acid,
ammonia, and sea-salt are to be found.
In the Report of the Royal Rivers Pollution Commission
of 1874, it was stated that half a pint of rain-water often
condenses out of about 3373 cubic feet of air. This is the
quantity of air a man breathes in eight days ; so that in
drinking a tumblerful of such water, which has washed
a dirty atmosphere, he swallows an amount of impurity
which would only gain access to his lungs by breathing
in eight days. Rain-water, where collected, say, 25
miles from a town, is not pure. It contains more organic
matter than deep-well water. It gathers impurities
from the atmosphere. Fine particles of organic matter
from animal and vegetable waste and decay are in dry
weather suspended for weeks in the air. By the conden-
sation of the moisture, they are entangled in the small
globules of water which form clouds and eventually rain.
The carbonic acid dissolved in the rain also attacks the
buildings of all large cities, disintegrating the stonework
and causing it to crumble away.
Dust Particles in Rain
It has been stated that minute particles of dust in the
air are necessary to the formation of rain. It has been
ascertained that these particles exist in the lower stratum
of air, even over the centre of the oceans, and the number
of these particles varies from 7600 per cubic inch of air
in the Indian Ocean to 30,000 in the Atlantic. In the
94 WATER : ITS ORIGIN AND USE
Indian Ocean as low a number as 3000 was found, but
that was after rain. In the lower stratum of air over
the land, as many as 60,000 per cubic inch have been
found.
As we rise above the surface the dust particles are
found to decrease in number. From observations on
the Bieshorn, Friedlander found 14,000 per cubic inch
at an altitude of 6700 feet, and only 2300 at 13,600
feet.
As a proof of the time that dust will remain suspended
in the air, and of the distance it will travel over the
mighty oceans, to assist in forming and bringing to our
shores the welcome showers, Darwin states, in The Voyage
of the Beagle, that dust has fallen on the decks of vessels
when far out in the Atlantic dust proved to be similar
to that raised high in the air by the harmattans of Africa,
and falling in such quantities " as to dirty everything on
board, and to hurt people's eyes a thousand miles from the
coast, and at points sixteen hundred miles apart in a north
and south direction. "
Rain-prints
Prints of prehistoric rain-drops are frequently discovered
in the rocks of the Carboniferous Period, during which
the coalfields were formed, proving that incessant rains,
which promoted the rapid growth of vegetation, were
general.
When the tide receded these rain-drops left their
impressions on the sun-dried flats of mud. On the return
of the tide they were again covered by a fresh layer
of sediment, which eventually hardened into rock, and
so the impressions, as we now often see them, were
preserved.
PREHISTORIC RAIN-PRINTS OX A SLAB OF SANDSTONE.
PORTION OF THE SAME SLAB, HALF NATURAL SIZE.
The arrow denotes the direction of the shower.)
[To face p. 94.
RAIN-PRINTS 95
The slab of sandstone shown in the illustration is a
perfect example of the manner in which these memorials
of prehistoric rainfall are preserved to us, and is of more
than ordinary interest.
With these flagging sandstones, it is a simple matter to
remove a layer from the surface. On removing a flake,
exactly one quarter inch thick, I found it parted from the
one beneath by a shining, pearly coating of mica, bright
with an almost metallic lustre ; this, however, is frequently
found lying along the planes of separation in these stones.
The second layer was also profusely marked with rain-
prints, but I was surprised to find that they were not
formed by a previous shower, in the sediment left by the
previous tide, but were identical with those on the surface
layer, and were as clearly impressed.
These facts are noted, as they tell us several things:
that rain at this period fell with great violence, enabling
it not only to leave its impression on the freshly deposited
mud, but to mark distinctly the partly sun-dried mud
from a previous tide. That the drops of rain were large
is also certain, for some of the casts on this stone are
half an inch in diameter ; that the wind was blowing at
the time is also beyond doubt, for the direction in which
the rain-drops fell is clearly apparent ; and that the thin
flake removed represented the sediment deposited by one
tide ; all these conclusions are considered by Mr J.
Allen Howe, the Curator of the Geological Museum,
who kindly examined a portion of the stone, to be most
reasonable.
It is not only casts or prints of rain that are preserved
in this way, for the rocks have yielded similar casts of
sun-cracks, worm-tracks, foot-prints of extinct birds and
animals, and other interesting evidences of life in past
ages.
96 WATER: ITS ORIGIN AND USE
In the Bay of Fundy the rise and fall of the tide ex-
ceeds 70 feet. This is a greater range than in any other
place in the world.
Here extensive mud-flats are left dry between the tides,
forming ideal places for the making of rain-prints.
Influence of Trees on Rain
Forests are found to attract rain. Hartwig says :
"They cool the atmosphere, their surface offering a
warmth-radiating area, so that the vapours readily con-
dense and descend in frequent showers."
Ruined forests mean flooded rivers, periodic droughts,
eroded soil, and dried-up springs.
Columbus records the frequent showers experienced
along the coasts of Jamaica, Madeira, the Canaries, and the
Azores, before their forests were destroyed.
Hugh Miller says : " Man is the only creature, of whom
we know anything, who has set himself to carry on
and improve the work of the world's original framer
who is a planter of woods, a tiller of fields, a keeper of
gardens."
I think we should not lay such flattering unction
to our souls, but also state some of man's more patent
works of destruction, especially with regard to forests.
It is man's place to enter this field of contest, not with
an indiscriminate slaughter of trees, large and small, as is
the custom of wood-cutters ; but, by an intelligent felling
of trees, to make the forests the most effective contribution
to human interests.
We have conclusive evidence that these islands of ours
were once as bountifully supplied with forests as other
lands. The following table, however, will give an idea of the
ruthless destruction of forests that has been going on here.
INFLUENCE OF TREES ON RAIN 97
Proportions of forest-land to total area :
Norway . . . .66 per cent.
Russia. . . . . 31
Sweden . . . . 29
Germany . . . 25
France . . . . 17
Italy 14
Belgium . . . . 10
Denmark . . . 6
Portugal . . . 5
Great Britain . . 4
Mercenary destruction means denuded mountain slopes,
the loss of historic forests, and " nature's revenge " in the
near future.
Bryant refers to this subject in the following lines :
""Before these fields were shorn and tilled,
Full to the brim our river flowed,
The melody of waters filled
The fresh and boundless wood.
The reckless and wanton destruction of forests has, says
Lord Avebury, ruined some of the richest countries on
earth.
Syria and Asia Minor, Palestine and the north of Africa
were once far more populous than they are at present;
they were once lands "flowing with milk and honey,"
according to the picturesque language of the Bible.
Why have deserts replaced cities ? It is mainly owing
to the ruthless destruction of the trees, which has involved
that of nations. Even nearer home a similar process may
be witnessed the Hautes- and Basses-Alpes are being
gradually reduced to ruin by the destruction of the forests.
Cultivation is diminishing, vineyards are being washed
away by flooded rivers, the population is dwindling, and
unless something is done the country will be reduced to a
desert ; until, when it has been released from the destructive
7
98 WATER : ITS ORIGIN AND USE
presence of man, nature reproduces a covering of vegetable
soil, restores the vegetation, creates the forests anew, and
once again fits these regions for the habitation of man.
Greece and Asia Minor have seen their fertility decrease
and vanish with their trees.
At Porto Praya, St Jago, the chief of the Cape de Verd
Islands, it seldom rains, but during a short portion of the
year heavy torrents fall. "On 16th January 1832 it had
not rained," says Darwin, "for an entire year. When
discovered, this island was clothed with trees ; the destruc-
tion of which has caused here, as at St Helena and some
of the Canary Islands, almost entire sterility."
The springs that once watered the Tuneberg, a range of
hills on the east bank of the Rhone above Strasbourg,
have failed since the peasants have hewn down the trees.
Many other instances of a similar result caused by the
destruction of forests have been recorded.
The destruction of forest trees in this country might
also be considered as disastrous.
We spend many millions annually on imported timber,
which we could supply from our own waste lands.
Dr W. Schlich, late Professor of Forestry at Cooper's Hill
College, states that in the United Kingdom alone we have
more than sufficient surplus land to produce the whole of
the timber we require, without touching existing woodland,
or putting a single acre out of cultivation.
Surely there is scope here for an energetic Government,
and an opening for the useful employment of hundreds of
idle hands.
Convict labour might profitably be employed in clothing
the barren spots with beautiful trees, rather than in
making useless forts, at the cost of millions, to receive an
enemy who will never reach our shores, or, should he get
thus far, would not be deterred by them.
INFLUENCE OF TREES ON RAIN 99
The people of every city, borough, and village should
put forth an effort to make beautiful the places in which
they live. Children should also be taught to protect and
not to destroy ornamental trees. Drunken hooligans who
so frequently destroy trees planted in the streets and
roads should be birched.
Unless the wholesale destruction of trees is not soon
supplanted by a reasonable and scientific method of
cutting, and reafforestation taken up with some energy,
there will, it is stated, be a shortage of timber within
fifty years. This is serious to contemplate.
Eeferring to the British Isles, Dr Schlich says :
" 6,000,000 to 7,000,000 acres of land would produce an
amount equal to all the ordinary species of timber
imported ; and there are 21,000,000 acres of waste,
heather, rough pasture, and land out of cultivation,
suitable and profitable for afforestation."
Many bodies having control of large tracts of land,
such as Water Boards, are planting their catchment areas
with trees with advantage and profit ; for it is found that
the presence of trees adds to the retention of water falling
rain as well as by radiation and cooling the adjacent
atmosphere, causing condensation and rain ; it prevents
floods, regulates and purifies the supply, for water from
wooded areas is generally purer than that falling on bare
land.
Thus we see that trees not only attract rain, but are
an all-round source of monetary gain ; in addition to the
aesthetic improvement of the locality, refreshing our eyes
and brains, as well as purifying the air, and covering with
verdure the waste and barren land.
The beneficial influence on our general health exer-
cised by the afforestation of neglected acres is beyond
dispute. The consumption of carbonic acid gas alone
100 WATER : ITS ORIGIN AND USE
by trees is an apparent gain to all who dwell in their
vicinity.
From observations taken at elevated German stations
in July, it was found that the surface soil in the forests
was 7 F. lower than in the open fields, and rather warmer
than the open fields in December.
It has also been found that the mean annual tempera-
ture of woodland soil at a depth of 4 feet is 2 to 3 C lower
than that of open country.
The mighty inland forests are not by their distance
from the coasts free from the ravages of man. The timber
is floated down the rivers, as in the case of the Manchurian
forests on the Amur. The logs from the forests between
China and Burma are floated 600 miles down the Yangtse,
their journey occupying about six months.
It is, however, satisfactory to note that many forests
are now being managed on scientific lines, so that their
ultimate destruction will be prevented.
Eighty to a hundred years are required to produce
timber fit for the sawmills.
Many of the mighty giants of the forests are of immense
age, certainly over 1000 years.
Although grand specimens are found all over this country,
it is the opinion of those best qualified to judge, that there
is no tree standing to-day which can be proved to be older
than 800 years. The rings formed by the annual growth
of exogenous trees are the best evidence of their age ; but
this can only be obtained before the hand of decay has
commenced operations.
The king oak in Windsor Forest is old and famous, and
the giant oak in Needwood Forest is proved by local
documents to be at least 600 years old, and within recent
times was far from the last stage of decay. A leviathan
is the Cowthorpe oak, near Wetherby, covering nearly
INFLUENCE OF TREES ON RAIN 101
half an acre ; and another grand old landmark stood at
Tilford, near Farnham, and is said to have been mentioned
in a charter granted by Henry de Blois, 1256.
James Rodway says : " Trees and rivers are interdepen-
dent upon each other. Even in the midst of a prairie, the
course of a river is shown by a double line of trees. Is
there not some connection between them ? Is the river due
to the forest, or the forest due to the river ? Experience
goes to prove that springs are conserved in a well-wooded
country, and that they dry up if a great clearance is made.
In Guiana it is certain that thunderstorms are more
common over the forest than over the sea.
Not only do forests affect the rainfall, they greatly
influence the climate of a country.
In the years 1852-62, 70,000 acres of the stately and
magnificent forests in Mauritius were denuded, causing
drought and floods, with disastrous results ; rainfall
diminished ; rivers dwindled to muddy streams.
Innumerable examples could be found of a similar kind.
Where land is devoid of vegetation, rainfall is almost
impossible. The fierce rays of the sun heats the surface ;
the air in contact then becomes heated too, and will there-
fore hold more and more moisture, and rain will not fall.
If there be abundant vegetation the vapours readily
condense, as above described; for vegetation quickly
radiates its heat into space, and becomes colder than the
earth. It is one of the laws of nature that whatever tends
to lower the temperature of the air below dew-point is a
cause of rain.
The influence of trees on the atmosphere is also ap-
parent. A considerable portion of the rain falling upon
forest trees is at once taken up by the leaves. The roots
also supply the leaves with moisture, which evaporates
from them, and so adds to the humidity of the atmosphere.
102 WATER: ITS ORIGIN AND USE
The evaporation of a wood in one day of summer is said
to be equal to 1 inch of rainfall, adding this proportion
of vapour to that in the atmosphere brought from the sea
by the winds ; and this very act of distillation, says one
writer, makes every forest a great refrigerator.
Darwin, referring to this, quotes, when at Rio de Janeiro :
"As soon as the rain ceased, it was curious to observe
the extraordinary evaporation which commenced over the
whole extent of the forest. At the height of a hundred
feet the hills were buried in a dense white vapour, which
rose like columns of smoke from the most thickly wooded
parts, and especially from the valleys. I observed this
phenomenon on several occasions. I suppose it is owing
to the larger surface of foliage previously heated by the
sun's rays."
Local rains are often due to large areas of woodland.
Forests cause precipitation from clouds that have passed
over the plains and still withheld the grateful showers.
" Mountains and rocks," says James Rod way, " are im-
posing, and cataracts force themselves on our attention
by their deafening noise ; but in the absence of a setting of
green, or clumps of trees, they are lifeless.
" It is the earth, ' with verdure clad,' which appeals to
the mind, and which does so much to promote the higher
civilisation. The snow-bound and ice-clad earth of the
north, and the burning sands of the desert soon become
monotonous and dreary, and the wilderness of houses in
a great city produces a weariness which only the open fields
and woods can relieve."
Before leaving this subject, we might well call to mind
one benefit we derive from the destroyed forests of bygone
ages. Here the ruthless destroyer was nature, and her
destruction was wisdom, not folly, for no man was upon
the face of the earth to require the timber. I refer here
INFLUENCE OF TREES ON RAIN 103
to the formation of coal. From these wrecked primeval
forests we derive our chief supplies of coal, with all its
attendant comforts and blessings, such as heat, light,
wealth, power, etc.
These stately forests, with their gigantic trees, were
destroyed by storms and inundations, only again quickly
to spring up in the swampy lands and humid atmosphere,
to be again destroyed, and suffer the interment of endless
ages, during which chemical changes took place. Within
the great laboratory of the earth's crust, "exposed to
water, temperature, and great pressure, the gases in the
vegetable matter were driven off, thus increasing the
carbon, turning it into peat, lignite, bituminous coal, and
ultimately anthracite and graphite, which is practically
pure carbon." Thus was our coal formed, and by upheaval
was again brought above the face of the waters, and made
accessible to man, to be consumed for his pleasure and
needs as a servant and mechanical force. Its constituents
were released by combustion, once again to join the
atmosphere from which they originally came, to be again
built into the structure of trees to gladden our sight and
glorify the earth, and again be utilised for the use of man,
and again by decay or fire to be consigned to the earth
or the atmosphere, and so continually to assist in the
perpetual repetition of nature's wonderful economy.
Referring to this most interesting subject, a corre-
spondent of the Daily Telegraph writes : " Ages before
man appeared as the chief actor on the world's stage, great
forests were in existence, taking their part, whilst living,
in the preparation of the earth's surface for the master-
piece of creation, and in death providing materials to be
laid away in nature's storehouse for the use of man
thousands of years afterwards. It is scarcely possible to
overestimate the part filled by trees in the history of the
104 WATER: ITS ORIGIN AND USE
world, or in the life and development of its human inhabi-
tants. Of the beauty of the primeval forests one can but
draw an imaginary picture ; but, composed as they were of
the most fantastic growths, they must have presented a
very striking appearance. During the ages which suc-
ceeded, the changes were many, and trees of quite another
character were evolved, such as firs and palms ; then came
leaf-bearing trees similar to those of our own day."
It is to be regretted that, owing partly to our want of
success in the perfection of the various mechanical con-
trivances used for the combustion of coal, the heat and
power wasted in the process amounts to astounding pro-
portions.
There is certainly a little consolation in the fact that
the earliest engine made consumed one bushel of coal in
raising 5,000,000 Ibs. 1 foot (called foot-lbs.), whereas
modern engines would produce at least 100,000,000 for
the same amount of fuel.
Great as this improvement is, it is still far from satis-
factory ; and when we remember that the annual output
of the coal mines of Great Britain alone amounts to
250,000,000 tons, and the world's production for the year
1905 was 840,000,000 tons, we shall be able to form some
idea of the inroads we are making on the buried forests of
ages gone by.
Let us also try to form some idea of the proportion of
the above amount that is sheer waste. The results will
astound us.
" A first-class boiler will deliver to the engine 75 per
cent, of all the energy in the combustible, or, say, 10,875
out of a total of 14,500 heat units; or, allowing about
8 per cent, for ashes, 10,000 heat units for each pound
of coal burned. This represents 7,720,000 foot-lbs. of
energy, which, if all were utilised by the engine, would
INFLUENCE OF TREES ON RAIN 105
give 3'90 h.p. for 1 hour, or at the rate of 0'26 Ibs. of coal
for each h.p. per hour. But by the greatest refinement
in engines yet accomplished, the cost of a horse-power has
not been brought below 1 Ibs. of coal per hour, or 17 per
cent, of the energy delivered by the boiler ; while the
average engine uses 3 Ibs. of coal per h.p., and discharges
unutilised 93 per cent, of the energy delivered into it."
Unsatisfactory as these results appear, the cause of the
greatest waste and extravagance has not yet been touched.
It is the domestic fireplace, wasting almost the whole
of the heat of the coal. At least 99 per cent, of the heat
goes up the chimney ; less than 1 per cent, warms the
room. When we remember that these fireplaces are to
be numbered by the million, we can realise what a large
proportion of the available heat is lost.
These enormous proportions of waste of nature's gifts
in the production of heat are even more alarming when
we consider the waste in the manufacture of light. Pro-
fessor Sylvanus Thompson calls our attention to the slow
progress made by man in artificial lighting. Wood, fish,
and animal oils were the earliest substances used. In the
eighteenth century vegetable oils came into use. In 1802
coal-gas was used for this purpose. This was followed
by electric light. It is, however, the manufactured coal-
gas that is such a prolific source of waste. The Professor
says: "10,000,000 to 20,000,000 is spent annually in
Great Britain alone in the manufacture of artificial light,
and 99 per cent, at least of this colossal sum is thrown
away on mere heat." There is also the important factor
that not only is the heat unnecessary, but, at the same
time, we poison the atmosphere to an alarming extent,
for one bat's-wing gas-burner adds to the atmosphere in
one hour 536 cubic inches of poisonous carbonic acid.
Professor Thompson calls our attention to the fact that
106 WATER: ITS ORIGIN AND USE
the humble glow-worm, and the tropical fire-fly, and other
phosphorescent animals, produce a cold light with practi-
cally no loss of energy, while to produce one ray of light
we have to produce 99 rays of heat. If we but knew the
secret of these animals and how to avail ourselves of it,
we should get from electricity, gas, and oil at least 400
times the light we nowproduce from our light-giving sources.
Many natural objects produce light unaccompanied by
heat. Sir E. Kay Lankester tells us that, in the case of
luminous plants and animals for instance, glow-worms
the light is due to the oxidation of peculiar fatty matters
in their bodies, the oxidation being under the control of
their nervous systems ; so that they can become luminous
or invisible at will.
In all branches of nature's work she has provided for
our wants on a lavish scale. Surely it was necessary, so
lavishly do we waste them. We therefore not only
ruthlessly destroy the forests around us, but we are also
making serious inroads, by our ignorance and want of
economy in the manner of use, on nature's buried forests
of the ages gone by.
Signs of Rain
The reader will now be able to account in many ways
for the various indications of approaching rain. Some of
the old and well-known sayings in reference to the same
do not now appear to be so much a matter of prophecy
as of deduction.
I have frequently found the accuracy of the following :
" If the hoar-frost come on morning twain,
The third day surely will have rain."
"Without doubt the poem written by the celebrated Dr
Jenner (the discoverer of vaccination), as an excuse for
SIGNS OF RAIN 107
not accepting an invitation to join in an excursion, is the
finest piece of weather lore we have. It begins with the
familiar lines:
" The hollow winds begin to blow,
The clouds look black, the glass is low."
Should the reader be interested in the subject, I would
recommend him to read that excellent little book, The
Story of the Weather, by G. F. Chambers.
The words of Archbishop Benson form an ideal conclu-
sion to this chapter :
" Thus in their change let frost and heat
And winds and dew be given ;
All fostering power, all influence sweet,
Breathe from the bounteous heaven.
Attemper fair with gentle air
The sunshine and the rain,
That kindly earth with timely birth
May yield her fruits again."
CHAPTEE V
WATER
The Composition of Water
" What has not water done in the past history of the earth ? The
records of geology are mainly the history of the work of water."
TTNDALL.
WATER is a universally diffused liquid. It was classed
among the elements until the close of the last century.
It is colourless, tasteless, inodorous, a powerful reflector
of light, and a bad conductor of heat and electricity. All
substances capable of vibrating may be made to propagate
and convey sound. Sound travels through the air at the
rate of about 1090 feet per second, but through water at
the rate of about 4700 feet.
Joseph Priestley discovered oxygen in 1774, calling it
" dephlogisticated air." In 1781 he discovered that when
oxygen and hydrogen were exploded in a closed tube,
water was produced, and thus proved water to be not an
element but a compound of two gases.
The discovery of the composition of water was not
brought about by analysis that is, by resolving the com-
pound into its component parts ; but by synthesis that
is, by putting the constituents together and building up
the compound.
We may, however, briefly try to make this clearer.
An element consists of an indefinite number of atoms
108
THE COMPOSITION OF WATER 109
of the same kind. A compound consists of atoms of at
least two kinds.
Countless compounds occur in nature which can be
reproduced artificially ; thousands of compounds can also
be produced artificially which do not occur in nature.
All the molecules of an element are the same kind ; all
the molecules of a compound are also of the same kind.
The molecules of the former are composed of similar
atoms; those of the latter of dissimilar atoms.
The mixture of oxygen and hydrogen consists of mole-
cules containing the atoms of both oxygen and hydrogen.
The compound (water) formed from the above mixture
contains only one kind of molecule, compounded of atoms
of both oxygen and hydrogen ; while no separate molecule,
consisting of the atoms of oxygen or hydrogen, will be
found in it.
By weight 88'89 parts of oxygen unite with ll'll parts
of hydrogen to form 100 of water (ratio of 1-8).
The combining weight of hydrogen is 1 ; the combining
weight of oxygen is 16. The symbol H means 1 part
by weight of hydrogen ; the symbol means 16 parts by
weight of oxygen. The composition of water, then, is
expressed by the formula H 2 0, which means that it is
composed of hydrogen and oxygen ; that 18 parts by weight
of the compound are composed of 2 parts by weight of
hydrogen and 16 of oxygen.
Air is a mixture of gaseous elements, mixed but
not combined, each element retaining its own character-
istic property.
Water consists of two gaseous elements, but it displays
the properties of neither. It is not a blend or mixture of
the two : it is totally different, it is a compound.
These two gases, hydrogen and oxygen, may readily be
measured and mixed together in a tube, in the correct
110 WATER: ITS ORIGIN AND USE
proportions. They form, however, only a transparent
mixture of two gases, not water ; neither does the mixture
possess any of the properties of water ; and yet the tube
contains in the proper proportions all that is necessary
for the production of water.
Pass an electric spark through the tube ; the gases will
disappear, and in their place will be found a drop or two
of water, which water, if required, can again be decomposed
into the mixture of two gases as before. Here we see
the difference between a mixture and a compound.
The affinity of oxygen for hydrogen as measured by the
heat developed by their combination is very great, 68,376
units of heat being evolved in the combination of 16
grammes of oxygen with 2*005 grammes of hydrogen, the
product being liquid water 18 C.
Thus we see water is composed of two bodies, which
in their free state are known only in the physical condition
of gases.
No other chemical change excepting that stated can be
made in water.
If frozen into solid ice, it retains its chemical constitu-
tion, although it may have altered its physical form. If
converted by heat into steam, it is evaporated into invisible
vapour. The ice, the steam, and invisible gas will all
consist of oxygen and hydrogen in proportions exactly
similar to that of water. All these forms are dependent
upon temperature only for their maintenance. Reduce the
temperature and the gas reverts at once to water ; increase
the temperature and the ice returns to its original form
water.
Water in all its forms is also absolutely unlike either
of the gases of which it is composed, being neither a
supporter of combustion, like oxygen, nor combustible, like
hydrogen. Oxygen is a gas, the most widely distributed
THE COMPOSITION OF WATER 111
of all the elements, eight-ninths by weight of water,
one-fourth of air. About one-half of silica, chalk, and
alumina consist of oxygen. It exists largely in nearly
everything. It is estimated that within 60 miles of the
earth's surface it forms 50 per cent, of the elements that
compose the crust. Without it in our blood we could not
live. It enters into the constitution of nearly every rock
and mineral ; disintegrates our body after death, as well
as by respiration enabling us to live. Every plant, tree,
animal, bird, fish, depends for life on an ample supply
of it.
Like its partner in the composition of water, it is
invisible, tasteless, and inodorous. It is heavier than
air, having a specific gravity of 1-1056, referred to air
as TOO. It is soluble in water to the extent of 3 volumes
in 100 at ordinary temperature. It was first liquefied
in 1877 by intense cold and pressure, and it has also been
solidified.
The oxygen both in the atmosphere and in water acts
on various substances in the rocks, principally compounds
of iron, altering them by conversion into other compounds,
a simple instance being the familiar rust termed oxidation,
which is seen to scale ironwork exposed to the weather,
when unprotected by paint.
Pure hydrogen is a colourless, tasteless, inodorous gas,
very inflammable, burning with slightly luminous, but
intensely hot flame.
The most intense heat that can be produced is caused
by burning hydrogen in oxygen gas. A pound of hydrogen
will produce by combustion 9 Ibs. of water, and in so doing
produces 62,500 heat units, which is equal to raising the
temperature of 417 Ibs. of water from 60 F. to 212 F.
Two volumes of hydrogen with six of air form an explosive
mixture.
112 WATER: ITS ORIGIN AND USE
Hydrogen is the lightest kind of matter known, having
a specific gravity of -0693, atmospheric air being 1, and is
therefore 14 times lighter than air. It can be liquefied
by exposure to 650 atmospheres' pressure and 140 C.,
but remains liquefied at 320 atmospheres' pressure, the
temperature remaining the same. It is only slightly
soluble in water, and no liquid will dissolve it in great
quantity.
Molecules of Water
In the beginning of this chapter reference was made
to a molecule of water. Let us see what this really
means.
Lord Kelvin has shown that if a drop of water were
magnified to the size of the earth, its molecules would be
of a size intermediate between that of a cricket-ball and
of a marble. Now each molecule contains three atoms,
two being of hydrogen and one of oxygen. The molecular
system probably presents some sort of analogy with that
of a triple star, the three atoms replacing the stars
revolving about one another in some sort of dance which
cannot be exactly described. I doubt whether it is
possible to say how large a part of the space occupied
by the whole molecule is occupied by the atoms ; but
perhaps the atoms bear to the molecule some such
relationship as the molecule to the drop of water.
A molecule is the smallest particle of any body that is
capable of separate existence. The Rev. J. M. Wilson tells
us : " Water consists of separate molecules, each of which
is about 5oo.ooo.ooo f an * nc h ^ n diameter."
The number of molecules in one drop of water would
amount to a million million million millions.
It is these molecules that dart from the surface of the
SPECIFIC GRAVITY OF WATER 113
water and make vapour, penetrating among the molecules
of the air.
" They fly with a velocity exceeding that of a cannon-shot,
which is twenty miles a minute, for the distances, almost
inconceivably small, that separate molecules, and have
their direction altered by collisions thousands of millions
of times in a second.
" It is these infinitesimal molecules whose motions are
quickened by heat, so that they take more room, or expand,
and at a lower temperature contract. At a still lower
temperature they again expand, rearranging themselves in
exquisite crystalline order as ice.
" Those that evaporate carry with them stores of heat.
They are unalterable, permanent, incapable of growth,
decay, or destruction. There is nothing more wonderful,
nothing that fills the mind of anyone who can grasp the
above description with more awe, admiration, and rever-
ence, than the constitution of the properties of a drop of
water and its molecules."
" No one imagines," says the same writer, " that water
is an evolved product, or that it has acquired by develop-
ment its present properties. Such as it is, it always was.
How marvellously these original, unchanged, and unchange-
able properties of water contributed to making the earth
the suitable place it is for the development of life and
of man ! "
Specific Gravity of Water
Frequent reference is made to specific gravity, more
especially when dealing with ice and freezing. It forms the
key to some of the peculiarities of water.
The specific gravity of a body is obtained by weighing
that body while immersed in water. Subtract this
8
114 WATER: ITS ORIGIN AND USE
weight from the ordinary weight of the body to find
the weight of the water displaced that is, of a volume
of water equal to that of the body and the ordinary
weight of the body, divided by this, will be its specific
gravity.
To find the specific gravity of a substance heavier than
water, and not acted on by water
Weigh the substance in the atmosphere and then
in water. A = weight in air, a = weight in water; then
^
S.G-. = . We will suppose the two respective weights
A. a
to be 54*3 and 47'8 grammes ; specific gravity
54-3 54-3
= 00.
54-3-47'S 6-5
If the body is lighter than water, a sinker is attached
to the body to make it sink. A different formula is then
necessary.
The easier way, however, is by using an instrument
called the hydrometer, especially constructed for this
purpose.
The weight of a cubic foot of water at a temperature of
60 F. is 1000 ounces avoirdupois. This is taken as a
standard to which the specific gravity of all liquids and
solids is referred.
A number of competent men, by various means at various
times, have made careful experiments with the object of
finding out the mean density of our earth, as compared with
that of water, the results varying from 4'950, 5'44, 5'48,
5 - 66, to 6 - 565. For various reasons little reliance could
be placed on the first and the last, and 5 '66 is the result
of the most reliable and accurate research.
It is therefore found that the mean density of the earth
is 5 '6 times that of water.
SPECIFIC GRAVITY OF WATER 115
The specific gravities of the following substances should
be of interest :
Water, rain I'OOO
distilled, 39 . . . . -998
60 . . . . -999
212 .... -957
sea 1-026
Mediterranean . . . 1-029
Dead Sea .... 1-240
Ice at 32 -920
Atmospheric air .... '001205
Note. Distilled water is 815 times heavier than
atmospheric air.
The change of volume and density of water with change
of temperature is so small as to be generally overlooked,
but it varies as follows :
Density.
Weight of
cubic foot.
At Cent, or 32-0 F.
. -999884
62-417
Ibs.
, 1
33-8 .
. -999941
62-420
ii
,, 2
35-6 .
. -999982
62-423
ii
3
37-4 .
. 1-000004
62-424
11
4
39-2 .
. 1-000013
62-425
ii
5
41-0 .
. 1-000003
62-423
6
,, 42-8 .
. -999983
62-423
ii
,, 45
113-0 .
. -999038
61-823
100
212-0 .
. -95866
59-844
As an object lesson in specific gravity we have the air-
bladder or sound, the sac or bladder-like structure found
in some fishes, which by distension or contraction alters
the specific gravity of the fish, enabling it to rise or sink
at will, and so to adjust itself to the varying depth and
pressure of the water in which it lives. It also serves for
changing the centre of gravity of the fish.
The gas in the air-bladder of sea fishes is usually
oxygen ; that in fresh- water fishes is mostly nitrogen.
116 WATER: ITS ORIGIN AND USE
Evaporation
We have already seen that natural evaporation is the
turning of water or any other substance into vapour at
the surface only, and is carried out at all temperatures,
even below freezing point.
Ebullition, or boiling, on the other hand, is the turning
of water into steam throughout the mass of liquid, or the
heating of a fluid up to that point at which it is converted
into vapour, the bubbles of vapour rising to the surface
and breaking there, causing commotion or ebullition.
The surface of water sustains the weight of the atmo-
sphere. Before it can be converted into steam within the
mass, it must have a force sufficient to lift 14'67 Ibs.
per square inch of the surface of the vessel in which it is
contained (at certain pressure and level).
Water boils at 212 F. only when the barometer stands
at 30 inches. If this pressure be increased, the boiling
point will be raised, and if the pressure be lowered, the
water will boil at a correspondingly lower temperature.
If boiling be attempted on a mountain, it will be found
that, for about every 600 feet of ascent, water will boil at
1 F. lower temperature.
Whenever liquid becomes a vapour, it can only do so
by absorbing a large amount of heat.
By exhausting the air from a vessel containing water,
the liquid is made to evaporate rapidly. To effect its
evaporation, it abstracts heat from all the bodies in the
neighbourhood. By this means great cold can be produced,
and water may be made to freeze by its own evaporation.
Take a shallow dish full of water, support it over a
vessel containing a little pure sulphuric acid, and place
both under the receiver of an air-pump ; upon exhausting
the air, the water evaporates, the acid absorbs the vapour
STEAM 117
as soon as it is formed, and thus the rate of evaporation is
increased; the water, surrendering all its own heat to
produce vapour, begins to freeze.
If a cup of warm water be put under the receiver of
an air-pump and the air exhausted, it will commence to
boil rapidly, illustrating the fact that if the pressure be
diminished, ebullition will ensue at a lower temperature.
When water is heated until the thermometer rises to
212 F., ebullition commences. The heat still passes into
the vessel, but the thermometer does not rise. As in the
case of ice, it becomes latent in turning the water into steam.
To evaporate 1 cubic foot of water requires the con-
sumption of 7 Ibs. of ordinary coal, or about 1 Ib. of coal
to 1 gallon of water. If the fuel be dry wood, the quantity
would require to be about 1\ Ibs. instead of 1 Ib. of coal.
In evaporating and cooling of water intense cold is pro-
duced. Every pound of water evaporated has expended in
the process a loss of 966*6 heat units.
Steam
Steam is the vaporous substance into which water is
converted under certain conditions of pressure and heat.
In its perfect state it is transparent, colourless, and in-
visible ; when visible in the form of cloudy appearance, it
is condensed and is then water.
Water gives off vapour at all temperatures; but it
is generally understood that steam is the fluid given off
by water when heated to boiling point, when little globules
of vapour are formed, which rise to the surface, escaping
as vapour or steam.
The use of steam as a mechanical power was first
mentioned about 130 B.C., but the idea had no practical
results.
The mechanical equivalent of the amount of heat con-
118 WATER: ITS ORIGIN AND USE
tained in steam is of interest. It is found that 1 Ib. of
water heated from 32 F. to 212 F. (an increase of 180)
requires as much heat as would raise 180 Ibs. 1 ;
hence 180
1 Ib. of water at 212, converted into steam at
atmospheric pressure, absorbs as much heat in its
conversion as would raise 966'6 Ibs. of water 1;
hence. . . . 966'6
The units of heat contained in 1 Ib. of steam = 1146'G 3
This of itself does not convey to the mind of the
uninitiated any idea of the power of steam. To do so we
must proceed a step further. We have found the units of
heat, and, as we saw in the first chapter, each thermal
unit of heat contains a power of exerting 772 foot-
Ibs. Therefore, the mechanical equivalent, or the maximum
theoretical duty of this quantity of heat as contained in
1 Ib. of steam, is 772 Ibs. x 1146*6 units of heat = 885,175'2
Ibs. raised 1 foot high.
Steam at 212 occupies a space 1642 times as large as
the water from which it was generated; or it may be
more easily remembered that 1 cubic inch of water, when
evaporated under ordinary atmospheric pressure (temp.
212 F.), is converted into 1 cubic foot of steam (approxi-
mately), and that 26'64 cubic feet of steam at atmospheric
pressure weigh 1 Ib.
It is this fact that makes an explosion by bursting of
a boiler such a serious affair. Boilers could be burst
by cold water pressure without danger, but by steam a
different set of circumstances arises. A short explana-
tion of this will not only be of interest, but will also
help us to grasp some of the other facts mentioned in
this chapter.
The temperature of steam and water cannot be increased
STEAM 119
unless the pressure be increased. If the safety-valves be
weighted to the pressure of, say, 80 Ibs., the temperature
necessary to generate steam at this point will be 311'80 F.
If we increase the pressure to 100 Ibs., the temperature
necessary to create steam would be 327*58 F. ; at 400 Ibs.
pressure the temperature would be 445'15 F.
Take a more general pressure, say 100 Ibs., for our
example. Here, with a temperature of, say, 327 F., the
steam would occupy a space over 271 times larger than
water. If the boiler is unable to control this it bursts ; the
pressure of 100 Ibs. is at once relieved ; the steam explodes
with a report, occupying the space it naturally fills at
ordinary atmospheric pressure, of which the equivalent
figure is 271 to 1642, or 6 times its capacity, while the
water, being 115-58 F. above boiling point, immediately
explodes into vapour also, expanding to its natural volume
of 1642 times larger. Hence the awful devastation that
follows in the wake of an explosion of a boiler, steel
plates being rent like so much paper. Not a vestige of
water is left; it Ijas disappeared invisibly into the
atmosphere in the form of vapour. Compare these
figures with an explosion of gunpowder. The bulk of
the gases by the combustion of this substance when
expanded to ordinary temperature of the atmosphere,
is only about 240 times as large as the powder, or
about 8 times less space than steam demands at 212 F.
But Professor Abel says that at the moment of the explo-
sion the temperature (800 F.) would expand the volume
10 times, so the figures for comparison would really be,
gunpowder 2400, steam 1642.
We see here the care with which man must handle
nature's simple gifts in making use of them for his own
purposes. Who would imagine that such mighty powers
lurked in the clear, sparkling water, and the dreadful
120 WATER: ITS ORIGIN AND USE
results of not making careful calculations in order to
control them sufficiently and safely ?
The simple manner in which accidents may occur is
illustrated in the explosion of a traction engine at Maid-
stone, Kent.
The men in charge left their engine to obtain some
food, and on returning found, to their surprise, that the
steam-pressure gauge apparently indicated a low pressure
of steam. In reality it recorded a very high pressure, for
the hand had by some mischance passed the stop-pin on
the face of the gauge ; it had passed the highest figure and
had begun a second revolution of the dial. The men
made up their fires and increased the pressure, preparing
for a start, when they were hurled into eternity !
Let us deal with a small quantity of water, say 1 cubic
inch, and see what power it contains.
One cubic inch of water at atmospheric pressure is
converted by evaporation into 1700 cubic inches of steam,
and will produce force enough to raise 2120'14 Ibs. (about
a ton) 1 foot. One pound of good coal will evaporate 240
cubic inches of water, and will provide a force of 508,000
foot-lbs. (equal to 15 horse-power).
Latent Heat of Steam
Latent heat is that amount of heat which exists in any
body without producing any effect upon another, or upon
the thermometer. It is also termed insensible heat, as
distinct from sensible heat. It is given out, or becomes
sensible, during the conversion of vapour into liquid, and
of liquids into solids. On the other hand, a portion of
sensible heat disappears, or becomes latent, when a body
changes its fprm from the solid to the liquid, or from the
liquid to the gaseous state.
LATENT HEAT OF WATER 121
If the reader refers to the details of the mechanical
equivalent of heat, he will see that the converting of water
at 212 into steam at 212 absorbs 9 66 '6 units of heat,
there being no increase in the temperature ; therefore, the
latent heat of steam is 966'6.
Latent Heat of Water
To illustrate the manner in which to determine exactly
the quantity of heat which becomes latent when ice is
converted into water, or water to steam (see Latent Heat
of Steam)
Provide a constant source of heat. Place a vessel con-
taining 1 Ib. of water over it, and note the extent to
which its temperature rises in a given time. We will
assume that it rises 10 in one minute.
Remove this vessel, and substitute one containing 1 Ib.
of ice at a temperature below 32. The temperature
will rise to 32, and will remain at that point a tritie over
14 minutes, at the end of which time the last particle of
ice will be melted. In this time the amount of heat
absorbed is sufficient to raise 1 Ib. of water a little over
140 (14'2 x 10 = 142), yet the water is still only 32. All
the heat has been used in turning the solid into a liquid, and
as it did not affect the thermometer, it is called latent heat.
Let the vessel still remain exposed to the heat. In 18
minutes it will have attained the boiling point, for 18 x 10
plus 32 = 212.
Let the vessel still remain until the water has entirely
boiled away. This will occupy about 95 minutes, or
nearly 5| times as long as it took to rise from 32 to 212 ;
and yet the temperature of the steam has at no time
exceeded 212. All this amount of heat, viz. 5 x 180 = 960
(more accurately, as previously stated, 966'6), has been
rendered latent.
122 WATER : ITS ORIGIN AND USE
If the steam given off in this experiment be conducted
by a tube into a vessel containing 5| Ibs. of water at
32, after some time this water will boil. It will now
be found that there is 6 Ibs. of boiling water in the
vessel, and that 1 Ib. of steam has been condensed, and
the latent heat of that was sufficient to raise 5 Ibs. of
water 180. It is this large amount of latent heat in
steam that renders it so useful as a heating agent. Heat
cannot be destroyed, but it is rendered sensible or given
out again when the steam becomes condensed.
Were it not for the latent heat of steam, the moment
water attained the boiling point would be a dangerous one
indeed. It would immediately be converted into steam,
with an explosive force equal to that of gunpowder ; for a
cubic inch of water, when converted into steam, occupies
nearly a cubic foot of space.
As a simpler example of a solid becoming a liquid,
rendering latent a certain quantity of heat
If equal parts of water at 32 F. and 174 F. be taken
and mixed together, the temperature of the mixture will
be the mean of the two, or 103 F.
Take equal weights of ice at 32 F., and water at 174 F.,
mix as before, and the temperature will be found to be
only 32, not 103 ; all the ice would be melted, and the
142 of heat has then been consumed in melting the ice.
To convert a cubic yard of ice at 32 F. to water at 32 F.
would absorb the wliple of the heat emitted by the com-
bustion of 1 cwt. of coke.
Specific Heat of Water
Various substances require different amounts of heat
in order to raise the same weight to an equal temperature.
This is called the specific heat.
Water is taken as the standard. The thermal capacity
SPECIFIC HEAT OF WATER 123
of a unit mass of cold water is unity, and the number
which denotes the thermal capacity of a body expresses
the mass of water which has the same thermal capacity
as that body. The thermal capacity of unit mass of a
substance is called its specific heat, and is identical with
the ratio of the thermal capacity of any mass of that
substance to that of an equal mass of water.
So the specific and latent heat of bodies is ascertained
by finding the amount of ice the body melts in cooling, or
from the increase in its temperature it produces in the
water around it.
If water and mercury are both subjected to the same
amount of heat, the mercury will be found to have a
much higher temperature than the water. Water, having
absorbed the heat, gives very little out.
Mercury can only contain one-thirtieth of the heat taken
in by the water. It gives off a much larger quantity, and
therefore has a much higher temperature. Therefore it
takes 30 times as much heat to raise the temperature of
1 Ib. of water 1, as to raise the temperature of 1 Ib. of
mercury by the same amount.
The following table gives the specific heats of a few
common substances :
Water. . . 1-0000
Alcohol -6603
Ice -5040
Aluminium . . . . . *2143
Iron -1138
Copper -0952
Mercury '0333
Gold -0324
Platinum . . . . '0324
Lead -0314
The specific heat of water is greater than that of any
other substance ; therefore, the sea always tends to preserve
124 WATER: ITS ORIGIN AND USE
a uniform temperature. For this reason islands have a
much more even temperature than continents. They do
not experience the extremes of heat and cold ; for the sea
absorbs a great deal of heat when the temperature is high,
giving it out again as the temperature falls.
Maximum Density of Water
Warm water is lighter than cold. Water attains its
maximum density at 39'2 F. As the temperature ap-
proaches the point of solidification (32 F.), the increase of
volume is slow and gradual ; at 32 F. the water begins to
turn into solid crystals of ice. (See p. 113.)
Let us make this point clearer, viz. that water
expands before freezing, while it is still liquid. If hot
water be taken, and cooled gradually, it will contract
slightly and continuously until it reaches 39 '2 F. ; no
further contraction occurs, it is now at its heaviest
temperature. If the process of cooling be continued, the
water will be found to expand slightly for the next few
degrees, until freezing point is reached, when its expansion,
with solidification, is both sudden and intense.
Congelation of Water
Solid iron floats on molten iron, as ice floats on water.
Were it not for the fact that water increases in volume
after passing below 39, all lakes, as the cold water from
the surface gives place to the warmer from below, would
in time reach 32, and the water would be formed into a
solid mass of ice, killing all fishes and other living in-
habitants ; but by the wonderful provision of nature, as
water approaches 32 it increases in volume, throwing a
protecting mantle of ice over the water.
We have seen that water boils at 212 F. ; mercury,
however, requires 660 F.
CAUSE OF EXPANSION 125
With alcohol it is very different. This boils at 173 F.
at atmospheric pressure, and if placed under the receiver
of an air-pump, it will boil at ordinary temperature.
Mercury freezes at 39 F., but the congelation of alcohol,
which has only lately been achieved, takes place at a
temperature of 203 F., for which reason this is the
liquid selected for recording very low temperatures.
Cause of Expansion
Contraction is caused by the molecules of water approach-
ing each other as the water cools ; but at 39 new forces
come into play, and the molecules rearrange themselves,
demanding more room in the process of solidification.
Water does not always freeze at the same temperature.
If the temperature be gradually reduced, and the water
be kept perfectly still, 3 or 4 below 32 F. may be
reached before ice begins to form; but the slightest
movement will turn it to ice, or if the smallest particle of
ice be in the water, this experiment cannot be carried out,
for ice will then form at 32. Ice, however, invariably
melts at a fixed temperature.
Compression of Water
Air may be compressed almost indefinitely, and on
pressure being relieved it regains its former bulk; but
water is practically incompressible. It has been found
that a pressure of ^15 Ibs. per square inch will compress
water only 51'3 millionths (or -00005) of its bulk.
Under a pressure of 1 atmosphere (15 Ibs. per square
inch), the following reduction in volume takes place. In
Alcohol .... -00216 per cent.
Ether .... -006158
Mercury . . . . '000265
Water -004663
126 WATER : ITS ORIGIN AND USE
Temperature and Pressure
The freezing point of water is lowered by pressure.
A cylinder of water under pressure remains liquid at
below 32 ; but if the pressure is removed it turns at
once to ice. If water be prevented from expanding it
cannot freeze.
The boiling point of water is raised by pressure.
"Water, even in open vessels, may be lowered many
degrees below its freezing point and still remain liquid ;
it may also be raised to a temperature far above boiling
point and still resist boiling.
This is due to the mutual cohesion of the water particles,
which resist the change of the liquid either into the solid
or the vaporous condition.
If you throw a particle of ice into overchilled water,
cohesion is ruptured and congelation immediately sets in.
If into superheated water you introduce a bubble of
air or steam, cohesion is likewise ruptured and ebullition
immediately commences (Faraday).
Matter in Suspension
All water, whether fresh and pure, or salt and full of
impurities, is derived from the rainfall.
Rain-water is the purest water obtainable, and is really
distilled water, distilled by nature ; but it gathers im-
purities from the atmosphere on its journey to the earth :
oxygen and nitrogen and carbonic acid gas.
When falling through the air over or near towns, it
dissolves sulphurous acid gas and ammonia.
" Both sulphate and carbonate of lime, apart from their
occurrence as independent minerals, are almost universally
diffused throughout the world's crust (as well as in the
HARDNESS OF WATER 127
waters of the ocean). The sulphate is appreciably soluble
in pure water ; while the carbonate, though practically
insoluble in pure, is quite decidedly soluble in carbonic
acid water."
After rain has fallen on the earth, in passing through
soil, sand, and rock it gathers up soluble inorganic matter,
together with organic matter.
By continued filtration through the ground the former
(sulphate and carbonate of lime) is increased, the latter
diminished.
If filtration is sufficiently perfect the organic matter
is altogether eliminated, the oxygen combining with the
injurious nitrogenous compounds, and the resultant acids,
with the alkalies of the soil, forming harmless nitrates.
Hardness of Water
The difference between hard water and soft water con-
sists in the relative quantities of bicarbonate of lime in it.
Water of less than 5 of hardness is considered " very
soft," 5 to 10 " fairly soft," 10 to 15 " neither hard nor
soft," 15 to 20 " moderately hard," 20 to 30 " hard,"
over 30 " very hard."
There are two kinds of hardness, permanent and
temporary. The former is due to the presence of sulphate
of calcium ; the latter is due to bicarbonate of calcium
(lime).
When water is boiled, the bicarbonate is decomposed,
yielding the insoluble carbonate as a deposit.
The water of the Thames Head well, near Cirencester,
is said to contain 27'44 parts of solid matter in suspension
per 100,000. This consists principally of carbonate of
lime, the hardness being 23, of which 18 is temporary
and 5 permanent.
128 WATER: ITS ORIGIN AND USE
Ordinary good chalk water would have a hardness,
averaging about 20 temporary (before boiling), and about
3 to 4 after boiling. As a rule it is exceedingly pure, and
from a domestic point of view all that can be desired.
Some waters possess a hardness up to 200.
One sample from a boring 165 feet deep at Longeaton,
in Derbyshire, which passes through red marl, permeated
by bands of gypsum, was described as being "a nearly
saturated solution of sulphate of lime." It had a total
hardness of 116, and a permanent hardness of 115, and
was absolutely unfit for use.
Hardness and its Influence on Health
The hardness of chalk water has given rise to much
discussion ; various opinions have been given as to its
deleterious effect on the health of the population.
The following table from the sixth Report of the Rivers
Pollution Commission is very clear upon the point :
No. of cities.
Population.
Degree of hardness.
Rate of mortality.
26
73,000
under 5
29-1
25
81,000
5 to 10
28-3
60
44,000
over 10
24-3
London
3,250,000
16 to 32
24-6
Other returns show similar results, and the opinion of
the Commission was that " both soft and hard waters are
equally wholesome, and we give no preference to soft
water."
I am of opinion that hard water is beneficial to the
human system to a far greater extent than we are gener-
ally aware, especially to children and young people, the
lime in the water helping to build up their frames.
Children cannot drink too much of this water ; for it
has been noted that in hardwater districts the absence of
HARDNESS: ITS INFLUENCE ON HEALTH 129
rickets is apparent, and the inhabitants generally have
better teeth than those living in soft-water districts.
If this is so, the whole frame must also derive an equal
benefit, though not so apparent, even though in a few
isolated cases hard water may perhaps prove injurious to
persons of mature age.
Wanklyn, in his practical treatise on water analysis,
says : " The Metropolitan water contains 4 or 5 times
as much solid matter as the Manchester and Glasgow
waters.
" The healthiness of London is higher than either, and I
am warranted in saying and maintaining that a high solid
residue in drinking water can have no very markedly
injurious effect on public health.
" London proves it. Here the major part of the solid
residue consists of carbonate of lime. Subtract this, and
the rest of the solid residue will not be much higher than
the water of Manchester, and other soft waters.
" If in a few isolated cases hard water is injurious, the
difficulty is easily overcome, and the hardness removed by
boiling."
The following remarks in the Lancet will be of interest
to many :
" It is a popular, but probably wrong, impression that
hard drinking waters are prejudicial to the health, and
moreover are injurious to delicate skins when used
regularly for ablutionary purposes. Gout, kidney disease,
and dyspepsia, by an interesting line of reasoning, have
been supposed to be due to, or aggravated by, the drinking
of excessively hard water. Some mysterious connection
between the chalk of the water and the formation of
" stone " in the kidney, or of " chalk " in the joints, in
gout, is a favourite speculation with many ; but in the
history of the world's water supplies there is no trust-
130 WATER: ITS ORIGIN AND USE
worthy evidence that the drinking of hard water influ-
ences for the worse these diseases. The idea is, in fact,
chimerical. "
It may be added that a Eoyal Commission some years
ago reported that where the chief sanitary conditions are
observed with tolerable uniformity, the rate of mortality
is practically uninfluenced by the softness or hardness of
the water supplied to different towns.
In an article dealing with this subject, Dr A. T. Schofield
remarks: "The best water is fresh spring water. This,
however, is a luxury that is rarer than good wine, and the
bulk of the population have no idea what such a water is
like."
Precipitation of Lime in Water by Boiling
The simplest way of softening water is by boiling. The
greater the heat, the greater the amount precipitated, as
will be seen from the table given below.
In this process the bicarbonates of lime and magnesia
are decomposed into free carbonic acid, which escapes, and
insoluble carbonate of lime and magnesia, which are pre-
cipitated. The hardness thus removed was the temporary
hardness ; that remaining, consisting principally of the
sulphates of lime and magnesia, is termed the permanent
hardness.
Temperature 217 F. . . 50 '0 per cent, deposited.
227 . . 60-5
236 . . 69-0
250 . . 81-7
261 . . 90-3
290 . . 100-0
One degree of hardness implies that each gallon of
water contains 1 grain of bicarbonate or sulphate of
lime, and that 1 Ib. of soap for each degree of hardness
CLARK'S METHOD OF SOFTENING 13 1
will be required to soften every 833 gallons of water ; or,
according to Clark's scale, oz. of soap will remove 1
from 10 gallons of water.
This appears to be a very serious item ; but when one
considers the few gallons of water that are used with soap,
in proportion to the other uses of water, its seriousness
to a great extent vanishes.
In the simple process of washing our faces, we do not
soften the whole basinful of water, but only the small
quantity on our hands, or the article we are using for the
purpose.
We should therefore think seriously before we condemn
water for its hardness, and convert the hard, bright,
sparkling, natural water into soft, insipid, " treated "
water.
No doubt, as far as the domestic boiler and kettle are
concerned, we have some cause for complaint. For when
these precipitated matters form a scale or deposit in any
article in which water is boiled, there is a loss of heat.
This scale, being a bad conductor of heat, possesses 27 per
cent, less of heat-conducting power, as compared with the
shell of the boiler. If the scale formed be inch in
thickness, we shall have to burn 15 per cent, more coal to
produce the same results.
In the case of large boilers for raising steam, the diffi-
culty can be overcome in several ways ; but it is not within
the scope of our story to go into the subject in detail. One
method only will be described shortly.
Clark's Method of Softening
In this method of softening waters which contain
carbonate of lime (retained in solution by excess of
carbonic acid), lime is added until the excess of carbonic
132 WATER: ITS ORIGIN AND USE
acid is neutralised. When this has taken place, the
lime added, as well as that previously in solution, is
precipitated in the form of carbonate, only a minute
quantity remaining in solution.
This process will reduce the Thames and New Eiver
water to 3, or lower than if it had been boiled for one
hour, but will rarely bring any water below 2| of hard-
ness.
This process, in addition to reducing the hardness from,
say, 21'2 to 4'4 (as at Caterham), removes a large pro-
portion of organic matter, and any matter giving a colour
to the water. Where these latter considerations arise, of
course, softening has more in its favour.
Water Analysis by Professor Dewar
HARD WATER FROM THE CHALK
Results in grains
per gallon.
Appearance ..... Clear
Odour None
Reaction Slightly alkaline
Oxygen required .... O'OOO
NH (ammonia) .... O'OOO
Nitrogen 0'406
Nitrogen as combined nitric acid . 1'827
Colour of residue .... White
Total solids 27'20
Total chlorine 1'5 12
Equivalent to common salt . . 2478
Hardness before boiling . . . 20'12
after . . 3 '30
Organic carbon ) mQQQ ( O'OIO
Organic nitrogen J * ( 0'004
Remarks. This water is exceedingly pure, and free
from organic impurity.
SEA-WATER
133
SOFT WATER FROM THE LOWER GREENSAND
Results in grains
per gallon.
Appearance ..... Clear
Colour ...... Very pale blue
Reaction ..... Slightly alkaline
Colour of residue .... White
Total solid matter .... 22-800
Chlorine 1'SOO
Equal to chloride of sodium . . 2-950
Nitrogen as nitrites . . . O'OOO
Nitrogen as ammonia . . . 0*010
Oxygen required to oxidise organic
matter 0'004
Degree of hardness . . . . 0-780
after boiling . 0'780
Organic carbon (0'098 parts per
100,000) . . . . ' . 0-068
Organic nitrogen (0*003 parts per
100,000) 0-002
Carbonate of sodium . . . 16 '600
Sulphuric anhydride (S0 3 ) . . 1*160
This water, from the 664-feet artesian boring at Luton,
Chatham, is of great organic purity, remarkably free from
hardness, and carbonate of soda is present in unusual
quantities.
Sea-water
No attempt at an exhaustive treatise on water would
be complete without some reference to the nature of the
water of the ocean the home of the waters. The first
question that will probably arise in some minds is, " Why
is it salt ? "
Nearly all the water from springs and rivers eventually
reaches the sea, carrying with it all the dissolved sub-
stances gathered on its journey, principally carbonate of
lime and common salt. The former, however, is being con-
134 WATER : ITS ORIGIN AND USE
tinually appropriated by the marine animals. For the
latter there is but little use ; thus we find that in ordinary
sea-water salt is present in very large quantities.
These saline ingredients are generally found in the
proportion of 30 to 40 per thousand, and their presence
accounts for the density of sea- water, which averages 1-026 ;
but it varies even in the same ocean. It is greatest in the
North Atlantic Ocean; and in the passage of the trade wind,
where the evaporation is rapid, 1*02781 has been registered.
Among broken ice of the Arctic the density sinks to
1-02418.
The mineral that gives sea-water its special character
is sodium chloride, the proportion varying according to
whether the seas are open or closed ; to the distance from
the coasts, where rivers pour their fresh waters into it ;
to the amount of evaporation in the different regions ; to
the distance from the melting iceberg of the Polar regions ;
and to the depth of the water. It has also been found
that generally the greater the saltness the greater the
transparency. For instance, where the water is very salt
it will be dark blue ; where less salt, lighter blue. Where
the sea is near a river, and the saltness is greatly reduced
by dilution with fresh water, the colour is as a rule of a
greenish yellow.
A ship will carry more cargo in salt water than in fresh
when equally immersed. If a ship loaded in fresh water
proceeds to sea, it will be found that the mark made on
the side of the vessel in fresh water will be some distance
above the surface of salt water.
The fact that we can swim more easily in salt water than
fresh is due to the greater density of the sea-water, which
gives it greater buoyancy. (See the Dead Sea, p. 305.)
The following comparisons between fresh and salt water
are of interest :
ANALYSIS OF WATER 135
Fresh water. Salt water.
Greatest density . . 39-2 F. Freezing point
(variable).
1 cubic foot at 39 -2' F.
weighs . . . 62*348 Ibs. 64 Ibs.
1 gallon weighs . .10 Ibs. 10 -3 Ibs.
1 ton weight equals . 35 '943 ft. cube 35 ft. cube.
1 ton contains . . 224 galls. 217 galls.
Freezes at ... 32 F. 26 to 31 F.
according to saltness.
It is often found necessary to obtain water for domestic
purposes from the sea. This is done by distillation and
aeration. Aeration as well as distillation is necessary ;
for the process of evaporation and re-condensation gives
us fresh water, but with a " flat," most repulsive taste, and
a disagreeable odour.
Special apparatus for condensing water is constructed,
by which the steam is aerated on its passing from the
evaporator to the refrigerator.
The apparatus used for this purpose in the large ocean
greyhounds and many men-of-war will yield about 1
gallon of potable water from the sea for every pound
of coal consumed.
Analysis of Water from the English Channel
Water 963-74372
Sodium chloride .... 28'05948
Potassium chloride. . . . '76552
Magnesium chloride . . . 3'66658
Magnesium bromide . . . '02929
Magnesium sulphate . . . 2 '29578
Calcium sulphate .... 1*40662
Calcium carbonate .... -03301
Iodine ...... Trace
Ammonia ..... Trace
Oxide of iron )
> . . . .In some seas
Silver
lOOO'OOOOO
136 WATER: ITS ORIGIN AND USE
We have seen that water exists in almost everything, to
a far greater extent than we might have imagined.
A human body weighing 150 Ibs. contains about 113 Ibs.
of water, and requires daily for its sustenance, either as a
liquid, or combined with food, 5 Ibs. of water. This equals
more than half a gallon, and seems an enormous amount
to be consumed by an ordinary (non-thirsty) individual.
We shall better understand how we take in this
necessary amount without being aware of it if we con-
sider the amount of fluid that exists in various articles of
our diet.
Proportion of Water in Articles of Food
Bacon, pork, ham . . . .22 per cent.
Eggs 65
Butter . . . . 11 to 16
Richest milk 87
Cucumber 97
Salmon 75 ,,
Beef 73
Cabbage 89
Potatoes . . . . 75
Cheese 25 to 50
Strawberries 90
Apples and grapes . . . . 80
The Aquarium
All water contains air, but the air in water has double
the quantity of oxygen in it that is present in atmospheric
air, and for this reason the fishes have only to pass
through their gills (which fulfil the same functions as our
lungs) half the quantity of water they otherwise would
have to.
If fish were put into water that had been boiled, and
the air expelled, they would come to the surface and
THE AQUARIUM 137
breathe our air, and would eventually die unless the water
were aerated, and thus supplied with the proportion of
oxygen they require.
Aquatic plants give off oxygen to the water, and the
fishes breathe it, giving out carbonic acid, on which the
plants thrive ; so beautifully does nature arrange the
minutest detail of her work.
To manage an aquarium successfully the first considera-
tion must be the balancing of animal and vegetable life.
This is not by any means an easy task ; and resource is
generally had to changing the water, or artificially aerat-
ing it. When the fishes become exhausted owing to the
absence of sufficient oxygen in the water, they swim at
the surface, with their mouths taking the air from the
atmosphere.
No single hobby gives such a maximum of pleasure for
such a minimum of labour as an aquarium, and if the tank
be properly constructed, there is no fear of a leak. It is a
study of the most interesting kind ; but though little work
and attention is necessary, it must have that little.
Many readers are discouraged in starting an aquarium
by the usual statement in books on the subject that the
best water for the purpose is that from a river ; next, from
a clear pond ; next, clean rain-water ; last of all, hard
water from well or tap.
Now all the first three are more or less impossible to
obtain, from one reason or another ; but it is possible to
keep Prussian carp, dace, stone loach, tench, minnows,
golden carp (gold-fish), and the beautiful golden orfe in
water from the tap ; so we need not set out hopelessly, or
abandon the idea, owing to our distance from a clear river
or clean pond.
Two golden orfe completed twelve years' confinement
in my aquarium two years since ; but as they developed
138 WATER: ITS ORIGIN AND USE
cannibalistic propensities in the thirteenth year by devour-
ing the minnows, they have been turned into a pond, which
they much appreciate.
Many students, including the writer, with but little
spare time, fail also in attempting to run the aquarium on
really scientific lines not changing the water, but by
balancing the conditions between animal and vegetable
life.
Only one here and there can succeed in this, and that
only when ample attention can be paid to it, and situation,
water, light, and many other conditions are exceptionally
favourable; but the pleasure may be secured with ab-
solutely no trouble whatever by arranging a supply from
the domestic pipes direct to the tank. It is not a question
of the quantity of water, but the quality and convenience
of supply.
The cost is small, for the consumption of water would
not exceed 1 gallon per day all the year round for a large
tank, as in the winter no fresh water is required for a
week at a time, and then but little need be added.
If the supply be arranged to deliver downwards under
pressure, with the end of the pipe a moderate height above
the water, the jet need not be thicker than an ordinary
needle. It will then carry down with it into the tank the
atmospheric air, and if only turned on for, say, half an hour
per day, will keep the occupants healthy. When the jet is
forcing the air down, the fishes, especially the minnows,
will gambol and sport in the silver stream of air-bubbles
and water, darting up against the stream to the surface.
It is indeed a pretty sight.
Even when the water is supplied through a jet, by all
means introduce the water plants, snails, etc. ; but even
should these not thrive, the fishes will not suffer.
Given the above conditions, by the help of a good book,
THE AQUARIUM 139
such as Bateinan's Fresh-Water Aquaria (Upcott Gill), as
a guide to feeding, shade, etc., there should be no failure.
Of all water-plants, the Italian water-weed, Vallisneria
spiralis, is the favourite for many reasons, one being its
peculiar method of reproduction, and another its circula-
tion of sap, which can be seen by the aid of a microscope.
It is also a free producer of oxygen. Its air cells contain
air only, the juices of the plant being contained in separate
vessels.
Great pleasure may also be obtained during the summer
by making a partition with a sheet of glass for observing
the stages of development of the frog or the toad, from
the spawn, the tadpole, the growth of the hind legs,
followed by forelegs, and the absorption of the tail, finally,
the pretty little creature ready to jump out on the floor,
which he will do on the very first opportunity.
There is also the interesting triton, better known as the
water newt, which under suitable conditions will take to
tank life readily. It is very interesting to watch them
come to the surface to breathe, in doing which they make
a little popping noise, and to see the female lay her eggs
and wrap each in the fold of a leaf. Great pleasure is also
possible when these creatures shed their coats. The old
skin can, if care be used, be floated on to a piece of card-
board by the aid of a small brush; it will be found
complete even to its tiny toes.
This creature, in common with many other animals,
can reproduce its lost limbs. I trust the reader will accept
my word for this fact, and will not proceed to the cruel
sport of testing the statement.
There is the stickle-back, who will build a nest, if
conditions favour, like a muff. The female will lay her
eggs in it, guarded by the male, who will attack any fish
that may venture too near. He persuades many females
140 WATER : ITS ORIGIN AND USE
to enter the nest and deposit their eggs, until a sufficient
number be laid.
Nearly all fishes can be tamed and taught to feed from
the finger of their keeper, on whose approach they will
eagerly come to the near corner to be fed.
Instead of a partition in the aquarium, a separate globe
may be used for the purpose of observation, but space will
not admit of further treatment of this subject ; but there
are endless varieties of beetles, water-flies, bugs, scorpions,
snails, limpets, and worms, all equally interesting, and
worth a place where their development and peculiarities
may be studied.
" With plenty of light you will see," to quote Mr Gosse,
" thousands of tiny globules form on every plant, and even
all over the stones where the infant vegetation is beginning
to grow, and these globules presently rise in rapid succes-
sion to the surface all over the vessel, and this process
goes on continuously as long as the rays of the sun are
uninterrupted. Now these globules consist of pure oxygen,
given out by the plants under the stimulus of light."
Referring to the aquarium, Charles Kingsley says:
" These animals, their habits, their miraculous transfor-
mation, might give many an hour's quiet amusement to
an invalid imprisoned in a sick-room, and debarred from
reading, unless, by some such means, any page of that
great green book (of nature) outside, whose pen is the
finger of God."
CHAPTER VI
FORMS OF WATER
Dew
" The benediction of these covering heavens
Falls on their heads like dew."
SHAKESPEARE.
DEW is the water of the atmosphere deposited in minute
globules upon the earth. It does not fall, in the ordinary
sense of the term ; but after the sun has set, and the supply
of heat is cut off, vegetation that has been warmed by its
rays and has absorbed them, radiates its heat back into
space and becomes rapidly cooled, until it becomes lower in
temperature than the surrounding air. The result is that
the moisture from the lower stratum of air is condensed and
forms dew. The water vapour which is being continually
breathed out by plants also helps in the formation, for
on a still night it is supposed that the amount of water
deposited is more than could have condensed out of the
air coming into contact with the leaves of the plants, and
that the plant itself assists in the deposition of moisture
on its leaves. Dew is deposited, not on plants alone, but
on all objects that have become cooled by radiation.
Plants radiate their heat more freely than other bodies,
and so receive a greater proportion of moisture.
The annual amount of dew falling in Great Britain
is estimated as averaging a depth of 5 inches all over
141
142 WATER: ITS ORIGIN AND USE
the surface, and is always more abundant in maritime
countries than in the centre of large continents.
The surface of the earth is never cold, heat being radi-
ated from it continuously. For this reason dew is never
found on the earth.
Dew is not formed in cloudy or windy weather. The
clouds prevent the escape of heat into space by radia-
tion. Clouds, like grass and foliage, are good radiators,
sending back an amount of heat equal to that received,
and so the balance of the temperature of the earth and
atmosphere is maintained and no dew is formed, there
being no condensation. The wind, by continually chang-
ing the air in contact with the ground, prevents the
temperature from falling sufficiently low for the forma-
tion of dew.
Dew falls freely in some parts. Where it seldom rains
it falls heavily, and is nature's only means of preserving
vegetation in these thirsty regions of the globe, thus
providing every leaf with its allowance of moisture, night
after night, enabling it to grow and nourish.
Thus in the tropics during the intense heat of day the
amount of heat absorbed is very considerable. The vapour
also exists in great quantities owing to the excessive
evaporation. This, followed by the clear skies, makes the
conditions complete, and as a result we get dew deposited
very freely.
" In the South American forests," says Humboldt, " not-
withstanding the sky is perfectly clear overhead, rain
frequently falls in heavy showers, caused by the copious
formation of dew by the radiating powers of the tops of
the trees, in contact with the vapour-laden atmosphere of
the tropics."
In cold, damp climates little dew is deposited, as the
frequent presence of clouds prevents it. Fortunately, here
DEW 143
again nature has beautifully arranged for moisture to be
deposited where it is most needed ; for, as soon as the sun
shines, or the atmosphere becomes warmed, the dew
disappears, and is again absorbed by the atmosphere.
" Such did the manna's sacred dew distil,
White and entire, although congeal'd and chill ;
Congeal'd on earth, but does dissolving run
Into the glories of the Almighty Sun."
ANDREW MARVELL.
We often hear the pearly dew referred to as an emblem
of purity. This is far from right ; for dew, being princi-
pally condensed out of the lower stratum of air, naturally
contains a far greater amount of impurities than rain,
which is formed in the higher regions.
The instrument used for ascertaining the quantity of
dew which falls is called a drosometer (Greek drosos, dew),
consisting of a balance, one end of which receives the dew,
the other end carrying weights which are covered to
protect them from the dew.
Hartwig says : " The very name dew is refreshing, and
calls forth a host of pleasing ideas. How beautiful are its
diamonds, glittering, in all colours of the rainbow, on
verdant meads, or on the blushing petals of the roses ! "
Before leaving this interesting subject, it will be well
to mention one other useful purpose performed by the
condensation of the vapour in the atmosphere, and
deposited on the surface of pools, which are called dew
ponds, which, even in the driest weather, almost always
contain water. The origin of this supply is explained by
Professor Henry Kobinson in an article on water supply,
in which he says : " Under certain conditions evapora-
tion ceases, and water is condensed on the surface of
the reservoirs. On Salisbury Plain, and other elevated
districts on the Chalk formation, small ponds called " dew
144 WATER: ITS ORIGIN AND USE
ponds" are constructed on the tops of the hills, where
little or no surface water can run into them ; yet a small
supply of water is obtained, owing to the very heavy dew
arising from the condensation of the vapour which is
evaporated from the surface of the chalk."
Dew ponds are thought by many people to be natural
reservoirs ; but this is at any rate not always the case, for
the following description of their construction was given
me by an old " mist-pond " maker hailing from Wiltshire,
where these ponds are more or less common.
For a pond 60 or 70 feet in diameter, the depth in the
centre would be 7 to 8 feet. After the excavation is
complete, the surface is puddled, that is, made watertight,
a layer of clay being spread over the surface, and well
beaten down, or " puddled," to form an impervious bottom.
A layer of lime is then put over the clay ; this is covered
with wheat straw, which is well sprinkled with water.
The whole is then covered with chalk gravel.
My old friend would not agree with the theory that the
evaporation from the chalk assisted in replenishing the
ponds, which is no doubt correct ; but he could hardly
be expected to have grasped this point. He, however,
admitted that both dew and rain deposited on the surface
of the water helped to keep up the supply ; but it was
principally by the condensation on the vegetation trickling
into the pond that the supply was maintained. My
informant said that a dew pond could be made in any
convenient situation, and on any geological formation, but
that they were more successful on the chalk why, he
could not tell and that altitude had but little to do with
the spot selected. He preferred to make them on a dead-
level surface, as the objection to rain-water running into
the pond was that it carried dirt.
I pressed him as to why they are said never to dry up,
DEW 145
which he maintained is a fact, and added : " There is
always a certain amount of dew."
On the matter of the amount of yield of these ponds, I
could only gather, " All depends upon the season " a wise
and safe reply ! He was, however, keen to impress upon
me their entire independence of rainfall.
They are, it appears, ready for use, and yield almost
immediately on completion; and many farmers, at least
in Wiltshire, rely solely on these ponds for water for all
farm purposes.
" We have no water to delight
Our broad and brookless vales,
Only the dew-pond on the height,
Unfed, that never fails,
Whereby no tattered herbage tells
Which way the season flies,
Only the close-bit thyme that smells
Like Dawn in Paradise."
KIPLING.
On referring to White's Selbome, I find that in a letter
dated 7th February 1776, this interesting subject is treated
at some length : " To a thinking mind, few phenomena
are more strange than the state of little ponds on
the summits of chalk hills, many of which are never
dry in the most trying droughts of summer. One in
particular, on our sheep-down 300 feet above my house,
which, though never above 3 feet deep in the middle,
and not more than 30 feet in diameter, yet never is
known to fail, though it affords drink for 300 or 400
sheep, and at least twenty head of large cattle. Ponds in
the vales dry up, but those on the very tops of the hills
are but little affected." He sums up the reason as follows :
"The moister the earth is, the more dew falls on it at
night ; and more than a double quantity of dew falls on the
surface of water than on moist earth Hence water, by its
coolness, is enabled to assimilate to itself a large quantity
10
146 WATEK : ITS ORIGIN AND USE
of moisture nightly, by condensation, and the air,
when loaded with fogs and vapours, and even with copious
dews, can alone advance a considerable and never-failing
resource."
Surely there is ample scope for the energies of the pro-
fessional " dew-pond " maker on our north and south downs,
where there is the perpetual difficulty of finding a supply
of water for thirsty Hocks and herds.
Hoar-frost
When the temperature sinks below the freezing point,
after dew has fallen, the tiny globules of water take the
solid form ; the particles freeze, and hoar-frost is formed ;
and it is one of the prettiest sights one can see in winter,
the hoar-frost forming every conceivable pattern on the
bare branches, varying with the kind of tree, shrub, etc.,
on which it may be deposited.
"The mystery of crystallisation," says Kuskin, "by
which, obeying laws no less arbitrary than those by which
the bee builds her cell, water produced by the sweet
miracles of cloud and spring freezes into hexagonal stars
of the hoar-frost."
One can derive great pleasure from watching the manner
in which this most interesting form of ice will decorate
and beautify even barbed-wire fences, wire-netting, or iron
railings, and does not ignore the unsightly telegraph wires,
which now unfortunately make our main roads hideous ;
even the delicate spider-web is turned into an exquisite
sparkling net.
Sleet
Sleet is composed of snowflakes partially melted in
their fall by passing through warm air.
Mrs Aubrey Le Blond.
HOAR-FROST ON A TREE.
[To face p. 146.
HAIL 147
Of this least interesting form of all atmospheric conden-
sation, Eobert Burns says :
" The wintry west extends his blast,
And hail and rain does blow,
Or the stormy north sends driving forth
The blinding sleet and snow."
Hail
Hail is rain which has passed through a cold stratum
of air, and has been converted into ice. It is a curious fact
that hailstorms are most common in tropical regions, and
during the heat of summer, and they usually occur during
the hottest part of the day.
Darwin states that when at the foot of the Sierra
Tapalguen, he had ocular proof of the falling of large
hailstones. Hail as large as small apples fell with great
violence, killing a large number of deer and birds. He
also mentions that in 1831, in India, flat hailstones fell,
one being 10 inches in circumference, and concludes by
referring to the fact that their dinner consisted of hail-
stricken meat.
Hailstones have often fallen of enormous sizes. In 1697
Kobert Taylor, in Hertfordshire, found them 4| inches in
diameter. Hailstones of this size are fortunately rare.
There is no reason, however, to doubt the accuracy of the
statement, for, if it were not true, it would scarcely have
survived for 200 years. Hailstones up to 3 and 4 inches
in diameter have frequently been noted.
In referring to the curious shape and stratified appear-
ance at times assumed by hailstones, Professor Tyndall
concludes that it is due to the velocity with which they
fall, and that they must have encountered condensed hot
air in front of them, and rarefied cool air behind them.
The destruction of bloom and bud in orchard and vine-
148 WATER : ITS ORIGIN AND USE
yards by this visitant causes it to be greatly dreaded by
the fruit-grower.
On 2nd August 1906 very heavy losses were sustained
in portions of the counties of Huntingdon, Bedford, and
Cambridge by a terrible hailstorm which in many cases
completely ruined the crops. Hailstones, which were jagged
pieces of ice, were in many cases 5 inches in circumference.
They fell with a force sufficient to kill a flock of starlings
roosting on a tree. Rabbits were killed in the fields, and
many coveys of partridges. The damage to the crops was
estimated by practical valuers, who had carefully inspected
the storm area, at 20,000. The wheat, barley, and oats
were so threshed as to have the appearance of having
passed through the machine. At Stagsden the storm was
very fierce, the hailstones being larger than walnuts.
Windows were broken and the corn destroyed, while beans
were threshed and cut. In the village of Thurleigh many
windows were broken, and damage done to property, while
beans and oats were stripped.
A correspondent of the Daily Telegraph, writing from
Verviers, stated that damage to the extent of many thou-
sands of pounds was caused to property, fruit, and crops
by the phenomenal hailstorm. Orchards and nurseries
were completely ruined. The farmers were panic-stricken
on realising the damage that had been done, and feared
ruin. Nothing similar had ever been known. The hail,
in falling, was met by whirlwinds which massed it into
thick blocks, one of which weighed over 4 Ibs.
This recent visitation will serve to illustrate the severity
of a hailstorm.
Fog or Mist
Fog or mist is caused by a cloud formed near the ground,
or the surface of water ; or in river valleys where the air
FOG OR MIST 149
is nearly saturated with vapour rising from the water or
moist land, the cloud itself being caused by the condensa-
tion of the vapour in contact with the cold surface of the
earth, or a cold current of air.
Even this least interesting form of atmospheric precipi-
tates makes an attempt, as if to redeem its lost reputation,
of decorating all that comes in its way. It is attracted
by the delicate spider's web, on which it forms minute
pearly drops outlining every strand. Every twig and bud
will glisten with the transparent beads, which increase in
size until of necessity they fall to the ground, and their
places are taken by other tiny growing beads.
Ordinary white mist that we see in the country is the
unadulterated mist pure and simple, and is not nearly so
objectionable as its London relative.
The latter is practically the same as the former, but in
addition contains in suspension the smoke and impurities
of the city.
If a stream be warmer than the air, more vapour is
given off than can be dissolved in the air. This also causes
fogs, similar to those that prevail along the course of
the Gulf Stream. The Behring Strait is seldom free
from fog.
No words of mine are necessary to describe the injurious
effects of city fogs upon the respiratory organs ; but the
chief injury arises from the matter in suspension, and not
from the mist itself.
Kecent experiments prove that with fog, as with rain,
invisible dust particles in the atmosphere are necessary
for its formation. It will be well if we give some little
time to this matter of the dust particles in the atmosphere,
where they play such an important part.
From whence does the supply of these minute particles
come ? Dr Mill tells us that 20,000,000 meteorites reach
150 WATER: ITS ORIGIN AND USE
our earth daily. These are broken up by friction with the
air, thus supplying cosmic dust. He tells us that a puff of
smoke from a cigarette contributes about 4000 million
separate granules of dust. We have also the numerous
chimneys assisting in the work. All the elements of dis-
integration also provide their quota.
These dust particles are found even in the higher atmo-
sphere around the mountain tops, though in greatly re-
duced numbers.
It is to these minute particles of dust and vapour that
even more credit is now given, for their scattering of the
sun's rays gives the sky its clear blue appearance, the
finest particles giving the strongest blue to the light
reflected from it
The tints of sunrise and sunset, rain, vapour, twilight,
dawn, fog, mist, cloud, all rely on these invisible dust
motes for their formation and effect; for water vapour
never condenses except upon a solid substance, and the
dust particles provide the necessary nucleus. It is
stated that in air quite free from dust, water vapour has
been cooled far below the dew-point without condensa-
tion taking place. Upon admitting a puff of ordinary
dust-laden air, each dust mote becomes the centre of a
tiny globule of water, and condensation proceeds in the
usual manner.
Thus we see that fog or mist differs only from clouds in
the place of origin ; and, as Professor Huxley tells us,
" fog or mist is a cloud resting on the earth ; and a
cloud is a fog floating high in the air. In like manner
icebergs are often attended by fogs, simply because the
mass of ice cools the surrounding air, and thus precipitates
its moisture."
LIGHTNING AND STORMS 151
Lightning and Storms
" From peak to peak the rattling crags among
Leaps the live thunder, not from one lone cloud ;
But every mountain now hath found a tongue,
And Jura answers, through her misty shroud,
Back to the joyous Alps, who call to her aloud.
BYRON.
Lightning is a flash of light, resulting from a sudden
discharge of atmospheric electricity. How this comes to
pass, Dr Hugh Eobert Mill explains :
" When the electric potential of a cloud becomes much
higher than that of another cloud, or of the earth, a disrup-
tive discharge takes place between them, through the air.
The electrical energy is mainly converted into heat by the
resistance of the air, the particles of which become instantly
white-hot; but the passage of the electric current is so
rapid that only a brilliant flash is visible. The intensely
heated air expands suddenly, and then as suddenly con-
tracts, setting up a succession of air waves all along the
line of the flash, reaching the ear as a prolonged growl or
roar, or as a sharp, rattling explosion, according to the dis-
tance from the observer and to the direction of the flash.
" The sound is prolonged by the echoes from the earth's
surface and hills, or from the clouds."
The water in the atmosphere, no doubt, has a great in-
fluence on lightning and storms. It is found that clouds
are always charged with positive electricity, but during
heavy rains negative electricity has been observed.
It is supposed that the electricity is first developed or
generated on the molecules of water as they condense from
vapour, and combine to form clouds ; as there are billions
of billions of molecules in one drop of rain, we can more
easily account for the accumulation of electricity in the
atmosphere.
152 WATER : ITS ORIGIN AND USE
Thus water existing as vapour in the atmosphere and
in the ascending currents plays an important part in the
formation of thunderstorms ; for it is stated that where
the climate is dry and rainless, like that of Jerusalem in
summer, thunder is unknown.
Before a great thunderstorm, the lower air is usually at
an abnormal temperature and fully saturated with water
vapour.
Drops of rain are often individually electrified to a very
high potential, as is proved by the frequent occurrence of
"luminous rain," where the ground is feebly lit by a
multitude of tiny sparks given out by the drops as they
come near it. Flakes of snow are also at times strongly
electrified.
We have already seen how an ordinary fall of rain
purifies the air. The rain and thunderstorm combined not
only purify it by washing out the impurities, but freshen
it, storing it with ozone.
The electricity present in the air is at its maximum
twice a day in the morning and again a little after sunset.
In the evaporation of water electricity is evolved, and the
friction caused by the particles of watery vapour driven
by the wind also adds to its accumulation. The speed of
lightning is about 290,000 miles per second, or half as
fast again as the velocity of light.
Lightning is of four different kinds, viz. forked, sheet,
summer, and ball or globular. The first three are common ;
the latter fortunately rare, as it is very dangerous.
Sheet lightning is unaccompanied by thunder, and is
the reflection from the vapour and clouds of ordinary
lightning occurring at a considerable distance below the
horizon.
The ball or globular form moves more slowly than the
others, and when it comes in contact with any object
Mrs Aubrey Le Blond.
ON THE MATTERHORN THE WAY BLOCKED BY MIST.
Mr ft Aubrey Le Blond.
ABOVE THE FOG AND MIST, 12,000 FEET ABOVE SEA.
[To face p. 152
LIGHTNING AND STORMS 153
it explodes with a loud report, sometimes doing much
damage.
The distance of the storm may be gauged accurately.
Sound travels at the rate of 1120 feet in a second, in air
of ordinary temperature ; so when we hear the thunder five
seconds after the flash of lightning, we know it is about
one mile distant.
Here, again, water forms a factor for consideration.
Sound is more audible and will travel further in damp
than in dry air ; a sound that could not be heard in dry
weather could be heard distinctly in damp air.
Thunder can be heard at a distance of 30 miles ; an explo-
sion at 100. The firing at Waterloo was heard at Dover.
The eruption at Krakatoa was heard at Eodriguez, in the
Indian Ocean, 3000 miles away, the sound taking four
hours to reach this point. The air waves propagated by
the disturbance travelled round the whole globe seven
times with the same velocity as the sound waves, taking
thirty-six hours to complete each circuit.
Before leaving this subject, I cannot refrain from refer-
ring to the dread that some people have of thunderstorms.
The loss of life from lightning is, indeed, small compared
with that caused by storms of wind and the havoc they
play around our coasts, though they are not dreaded
nearly so much, at least by those on land, as thunder-
storms. I have known many instances where even adults
were prostrated with fear during a storm.
This fear is really the outcome of ignorance, combined
with superstition handed down from generations.
The poet Cowper may have had this in mind when he
wrote :
" Ye fearful saints, fresh courage take,
The clouds ye so much dread
Are big with mercy, and shall break
With blessings on your head."
154 WATER: ITS ORIGIN AND USE
We also find, in Longfellow's Golden Legend
" I hear the thunder
Mutter its curses in the air ;
The devil's own and only prayer."
Tf those who fear would only seek to know more of the
wonders of the heavens, instead of calling to mind the
superstitions of dark ages, there would be less fear. I
remember only too well being told when a child that
thunder was the voice of God speaking in anger ; it was
also supposed to be the forerunner of the last awful day.
Then followed the shutting or opening of windows, cover-
ing of looking-glasses, removal of fire-irons, etc., to the
basement. I have even seen adults, who should have
known better, sit with their heads buried in pillows, with
eyes covered and ears stopped. Such conduct is in itself
enough to frighten any sensitive child.
Lightning certainly causes death ; so does the innocent
orange peel. In fact, loss of life from lightning is so small,
that the possibility of danger may be altogether overlooked,
and the heavenly display enjoyed without fear.
The study of nature's wonders, which is becoming
general in our more enlightened times, enables us to
regard with reverent enjoyment spectacles which in by-
gone days were sources only of superstitious terror.
There is no doubt that many people have a genuine fear
of a thunderstorm without knowing why. I can only
assure them they will be well repaid by bravely trying to
admire this most sublime of nature's wonderful displays.
Waterspouts
We all have a vague idea what a " waterspout " is ; but
few of us have seen one. The dark spiral or tapering column
of cloud reaching down from the heavens, usually over the
RAINBOWS 155
sea, and more rarely on land, is caused by a whirlwind
which is itself caused by two currents of air being impelled
obliquely against one another and producing a whirling
motion. These two currents of air are usually of different
temperatures, causing the condensation of a considerable
amount of vapour, and producing heavy black clouds.
When a waterspout occurs over a large body of water,
its motion forms a conical column of vapour reaching
nearly down to the surface of the water, which is much
agitated, and it appears as if the sea is being sucked up.
This has been proved not to be the case, as the water
falling from the waterspout on the deck of a vessel is fresh.
Sometimes it travels over the land, and falls to the
ground with considerable force, making excavations in the
surface. The chief danger to shipping is from the violence
of the gusts of wind, though, should the waterspout strike
the vessel, which very seldom occurs, the effect is very
disastrous.
Rainbows
" Meantime, refracted from yon eastern cloud,
Bestriding earth, the grand ethereal bow
Shoots up immense ; and every hue unfolds
In fair proportion, running from the red
To where the violet fades into the sky.
Here, awful Newton, the dissolving clouds
Form, fronting on the sun, thy showery prism."
JAMES THOMSON.
Rainbows are the result of certain modifications which
light undergoes by reflection, refraction, etc., from drops
of rain and vapour, forming it into a bow or arc of a circle,
in which all the prismatic colours are shown, the radius of
the red bow being nearly 42.
A rainbow can only occur when rain is falling from
clouds opposite the sun while it is shining. The elevation
of the bow depends upon the altitude of the sun. The
156 WATER: ITS ORIGIN AND USE
rays strike the falling drops of rain and are refracted as
they issue into the air.
If the sun be on the horizon, it will form a complete
semicircle ; if the sun be at an altitude of 42, the bow
will be so depressed as to be hardly visible ; with the sun
at a greater altitude, the bow will be invisible, being
beneath the horizon ; therefore, if the observer be on a
mountain top, it is possible to see a complete circle.
A perfect rainbow has two concentric arches, the inner
(primary) and the outer (secondary), each formed of the
colours of the solar spectrum, but arranged in the reverse
order, the radius of the violet in the secondary bow being
almost exactly 54.
When a broken bow is seen, it is caused by the absence
of falling rain at the missing portion of the bow.
The manner in which the rays of light strike the
spherical surfaces of the individual drops of rain, or spray
of waterfall, etc., and issue from them, forming this most
interesting phenomenon, is beyond the scope of our story.
On more than one occasion the writer has succeeded in
making small portions of a bow in the simple process of
watering a tennis court with the garden hose. The display
was certainly feeble, but nevertheless interesting.
Halos, etc.
" The moon thro' banks of clouds unseen,
The glimmering streaks of light between."
Halos, coronas, aureolas, parhelia, and other phenomena
of this kind, are the names given to the coloured circles
sometimes seen round the sun or moon.
These optical phenomena are all more or less due to the
same cause as the rainbow, that is, the interference of the
rays of light by minute globules of vapour, rain, or minute
AURORA BOREALIS 157
crystals of snow, as in a cirrus cloud. When rays of light
pass through these a halo is formed.
When the light of either sun or moon passes through
fleecy clouds or globules of vapour, a corona is formed,
varying in accordance with the size of the globules.
When the constituent circles of a halo intersect, and an
image of the sun or moon appears, this is called a mock-
sun or a mock-moon, or parhelion and paraselene respec-
tively. These images are often tinted with prismatic
colours, as described by Professor Tyndall after an ascent
of Monte Eosa. " I looked upwards," he says, "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."
Anthelia are luminous rings, seen generally in Alpine
and Arctic regions, opposite the rising or setting sun ;
they are also due to the diffraction of light.
Aurora Borealis
The aurora as seen in the Polar regions is one of the
most interesting and beautiful sights it is possible for us
to imagine. It is considered by some to be of luminous
meteoric origin, caused by clouds of meteoric dust coming
into contact with our atmosphere ; but the more general
opinion is that it is caused solely by electrical discharges
in highly rarefied air, or in stellar space, and is not due to
any of the forms of water. But as some doubt exists as to
its real origin, I take this as an excuse for devoting a few
lines to the subject. The same phenomenon is seen in
equal, if not greater, splendour in the South Polar regions,
where, however, it is called Aurora Australia.
158 WATER : ITS ORIGIN AND USE
It is supposed to be caused by positive and negative
electricity emanating from the sun, which, coming into
the earth's magnetic field in the upper air, is attracted to
the Poles, discharging with a light similar to that emitted
by an X-ray tube.
The rays of the aurora have been known to reach the
earth. Sir W. R. Grove saw the rays between himself and
the houses, and other observers have had similar experi-
ences; but all altitudes up to 1000 miles have been given
by various observers.
If electricity be passed through rarefied air it exhibits
a diffused luminous stream of light characteristic of the
aurora, and magnetic storms are usually apparent in
connection with the display, accompanied by a noise like
the rustling of silk.
Although it is only in the regions more nearly approach-
ing the Poles that this phenomenon is usually seen, yet it
is occasionally visible even in the south of England. In
November 1905 the "northern lights" were seen as far
south as Kent.
There had been a fairly low temperature all day, with
hail at places (London), and snow was also reported in
many parts of the country.
About 6 P.M. the sky to the north appeared to be
covered with huge banks of vivid pink clouds, with shafts
or streamers of paler light running up and down every
few seconds. The colour of the sky deepened to a flame red,
then slowly faded away. In many parts it was thought,
by those who had never before seen the aurora, to be the
reflection of a large fire.
About 8.30 it reappeared, the sky presenting a glorious
spectacle, irregular clouds of a rich pink colour being
clearly visible even in the bright moonlight, which was
illuminating white fleecy clouds that filled the sky.
STALACTITES AND STALAGMITES 159
This is supposed to have been the most vivid display
ever seen in England, and those who saw it should indeed
be congratulated, for it was a rare sight.
What this display is like in the northern climes we can
only wonder. I have nowhere seen a better description
than that given in one of my old school-books :
" Darkness broods over the Polar world ; no object can
be seen moving over the wide expanse of frozen sea.
" Suddenly from east to west appears a beautiful arch
of living gold. The lights dart to and fro, their colours
rivalling those of the rainbow. Beyond the arch a stream
of golden rays shoots up far above the rest, and the stars
are obscured as ' the merrie dancers ' sweep along in waves
of light.
" There is something surpassingly beautiful in the
appearance of the true ' auroral curtain ' fringed with
coloured streamers : it waves to and fro as if shaken by
some unseen hand.
"Then from end to end there passes a succession of
undulations, and the curtain seems to wave in a series of
graceful curves.
" Suddenly, as it were by magic, there succeeds a perfect
stillness, as if the unseen power which had been displaying
the varied beauties of the auroral curtain were resting for
a moment. But even while the motion of the curtain is
stilled, we see the ultimate waxing and waning of its
mysterious light, and the noble span of the auroral arch,
from which the waving curtain seems to hang, gives a
grandeur to the spectacle which no words can adequately
describe."
Stalactites and Stalagmites
These interesting products of the work of water claim
a place in our study; for the knowledge gained in an
160 WATER: ITS ORIGIN AND USE
endeavour to follow the manner of their formation will
help us to understand many other curious works that
water, in a similar manner, performs, but producing
different, though not less interesting results.
We have seen that pure or distilled water, like rain,
readily absorbs, in various proportions, every gas with
which it comes into contact. The most prominent of all
is carbonic acid, without which there would be no stalac-
tites. Water at 60 will absorb its own volume of this gas.
Under normal conditions of temperature and pressure,
100 volumes of water dissolve 1'48 volumes of nitrogen,
2*99 volumes of oxygen, and 100*2 of carbonic acid, besides
ammonia.
This explains the manner in which the rain, originally
pure, becomes laden with such impurities as will enable
it to attack the rocks and to pick up matter in solution ;
carry it and deposit it as stalactites, and many other in-
teresting forms, a few only of which we shall be able to
describe. It is solely by the dissolving and removal of
solid matter, by the aid of water, that underground
channels, caves, etc., are formed in the solid rocks.
Stalactite Caves
In the boiling of water there is an escape of the free
and loosely combined acid, and the carbonate of lime is
deposited, forming a " crust " on the inside of the kettle ;
and when the water is sufficiently concentrated by evapora-
tion, the sulphate is likewise partly deposited. The de-
composition of the " bicarbonate," in fact, takes place, though
slowly, even at ordinary temperatures, where the water in
which it is held in solution is exposed to the atmosphere.
It is in this manner that the stalactites are formed.
Stalactites consist of a semi-crystalline deposit, usually
STALACTITE CAVES 161
of a conical or cylindrical form, found in caves of the
limestone rocks. They are formed by water percolating
through the rock becoming charged with carbonate of
lime, which is held in solution by free carbonic acid gas,
which the water gathers from the air and soil. When the
water reaches the roof of the cavern, from which it drips,
the gas escapes and so deposits the carbonate of lime in
the form of icicle-like pendants from the roof.
If the deposit be formed on the floor of the cavern the
shape is reversed, and pinnacles of this calcareous rock are
formed. These are called stalagmites. They sometimes rise
into columns, meeting and blending with the stalactites
above.
The rate of the accumulation of the stalactite and
stalagmite in caves varies. In the Ingleborough Cavern
a stalactite measured in 1839, and again in 1873, was found
to have grown at the rate of -2946 inch per annum.
The rate of growth varies with the amount of percolation
and the presence of varying currents of air.
These may be seen in the caves of the Kock of Gibraltar,
the grottos of Demoiselles, Arcy, and the Mammoth Cave
of Kentucky : this cave has been penetrated to a distance
of 14 miles. There is also at Buxton, in Derbyshire, a
stalactite cavern of considerable size, called Poole's Hole.
Kent's Hole, Torquay, has also a cave of this description.
A short description of the Adelsberg Cavern will be
of interest.
The grottos of Adelsberg are situated about 1 mile
from the market town of that name, in the province of
Carniola, Austria.
The cavern was known in the Middle Ages, but remained
undiscovered in modern times until 1816. The grottos
are of enormous extent, and fully 2| hours are occupied
in traversing them. The most extended of the ramifica-
11
162 WATER: ITS ORIGIN AND USE
tions cover a distance of over 2 miles, and consist of a
succession of stalagmite and stalactite chambers.
The temperature of this cavern is 48 F. The river
Poik flows into it some considerable distance, disappearing
into a subterranean passage, reappearing again lower down
under the name of Unz, only again to travel through
another stalactite grotto.
The largest grotto is the Franz Josef Elizabeth, which
is 665 feet long, 640 feet wide, and 100 feet high.
One of the grottos in this renowned cavern is called
the Cathedral, 72 feet high and 158 feet broad. From this
a staircase of 85 steps leads into the grotto called the
Ballroom, 150 feet long, 90 feet wide, 45 feet high, which
is illuminated every Whit-Monday, on which day the
annual ball is held.
There are many other remarkable grottos in this cave,
in which are statues, curtains, calvarys or crosses, columns,
and innumerable figures, all of natural stalactites and
stalagmites.
There are grand illuminations of the interior of this
cavern on certain days. Those who have been fortunate
enough to visit the grottos on these occasions, pronounce
the sight most impressive, and one not easily to be forgotten.
In Manville Fenn's Life of G. A. Henty, we read that
immediately below the entrance to the Adelsberg Cavern
a stream plunges into the earth, reappearing 10 miles
distant to the north. A piece of cork thrown into the
water does not emerge for twelve hours ; and it is stated
that this points to the fact that the underground ramifica-
tion of the stream must extend at least double that
distance.
In the same volume it is stated that in Carniola " rivers
of navigable size and depth issue from its mountains
rivers which far surpass the subterranean streams of
STALACTITE CAVES 163
Central France and these, after running for a few miles,
enter a cavern and lose themselves as mysteriously as they
appeared."
Nature's work in this direction is nowhere displayed
so marvellously or in such gigantic proportions as in the
Mammoth Cave in Kentucky, U.S.A., which was discovered
by a hunter named Hutchings, in 1809. Its entrance is in
a forest ravine 600 feet above the sea. The Main Cave is
40 to 300 feet wide, 35 to 125 feet high, 4 miles long.
The whole cavern and its innumerable winding passages
cover an area having a diameter of 10 miles, containing
about 150 miles of accessible avenues, cataracts of
falling water 250 feet high, lofty domes 300 feet high,
pits 190 feet deep. There is a wealth of crystal flowers,
ferns, canopies of fleecy clouds, and cascades of great
volume. Some of the underground streams are impassable
for seven months of the year ; and one of them, like the
Poik, disappears into the bowels of the earth. The
Mammoth Cave also contains extensive lakes. One called
the Styx is 40 feet wide and 400 feet long. The tem-
perature is 54 F., and the whole scene is really beyond
description.
The Luray Cavern, Virginia, U.S.A., is also of enormous
extent, containing innumerable grottos, corridors, halls,
avenues, etc. ; draped stalactite columns up to 50 feet
high, some 30 feet in diameter, some snowy white and
others pink, blue, and amber in colour. It contains no
stream, but has hundreds of little lakes varying up to 50
feet in diameter and from 6 inches to 15 feet deep.
It is indeed a wonderful work of nature cathedrals,
chasms, vales, balconies, bridges, cascades 40 feet high by
30 feet wide, with cataracts of milk-white, alabaster-like
cascades, every ripple of polished carbonate of lime de-
posited by the water.
164 WATER: ITS ORIGIN AND USE
Its area covers 100 acres, but there are several tiers of
galleries, the vertical depth between the highest and lowest
of which is 200 feet. The temperature of the cave is uni-
formly 54 F., similar to that of the Mammoth Cave,
Kentucky. It is visited by 12,000 people per annum.
The river Garonne is a notable example of a disappear-
ing river. It rises in Spain on the slopes of the Pyrenees,
and is fed by snow and ice waters of the Pic Nethou. It is,
however, swallowed up by a sink-hole known as Trou de
Taureau, reappearing 2 miles lower as a gushing spring
at the hill of Castellon.
There is a wonderful cave in Somaliland, situate about
30 miles south of Guinea. Here the river Web has carved
for itself a superb underground palace, as it dashes through
a mountain of quartz.
"It seemed," says Dr A. D. Smith, "as if nature had
confined herself to human ideas of the grand and the
beautiful in this work, so regular and ornate were her
designs. Passing columns and arches and altars of appar-
ently the whitest marble, the clear water disappeared into
the dark recesses of a pillared temple. I can give you,"
he says, " no idea of how ornate the columns were, with
their beautiful capitals and splendid bases, or of the
magnitude of the subterranean chambers."
Coming nearer home, we have in Belgium, 70 miles
south of Brussels, the vast limestone caves of Wamme,
Rochefort, Han, and Eprave ; also the subterranean river
Lomme, which disappears in the Rochefort Grotto and
reappears in the cave of Eprave. The caves of Rochefort
take some two hours to traverse : the principal chamber is
the Salle du Sabbat, nearly 300 feet high, draped with
stalactites.
The caverns of Han are of considerable extent, consisting
of galleries at various levels, leading to many large chambers,
STALACTITE CAVES 165
some decorated with stalactites : the largest, the Salle du
Dome, has no stalactites. It is 500 feet long, 450 feet wide,
and is about 180 feet above the river Lesse, which tra-
verses it. The visitors can also descend to the cavern Salle
d'Embarquement, on the Lesse, where they enter a boat
and are rowed out of the cave. The illustration of this
interesting chamber and subterranean river was kindly
given by Director Monsieur E. de Pierpont.
In the caves near Enniskillen (Ireland), of which the
marble arch is the most important, three rivers disappear
suddenly into three holes, and by erosion and corrosion
these underground rivers have enlarged the fissures in the
rocks, forming them into magnificent galleries of consider-
able area and length.
Near Gort, 1 miles east of Kiltarton (Ireland), is a river
which disappears into the earth and goes no one knows
where.
Peak Cavern (Derbyshire) is also a subterranean river
course.
The Manifold, in Staffordshire, also disappears into the
earth, through which it flows a distance of 3 miles.
Bagshaw Cave, at Bradwell, discovered in 1806 by
miners who were in search of lead, is also traversed by a
river which may be from 1 mile to 2 miles long. It ia
the torrent of Bagshaw Cave that feeds the source of the
river Bradwell.
In Yorkshire (Ingleborough) we have the cave of Gaping
Ghyll, which engulfs the large stream of Fell Beck, which
has a perpendicular fall of 300 feet into an abyss. At a
depth of 210 feet a large pipe, varying in diameter from
13 to 29 feet, opens in the vault of an immense subter-
ranean hall 480 feet long, 70 to 110 feet wide, and 80 to
100 feet high. Here the waters have excavated a reservoir
of 100,000 cubic yards' capacity, as well as about half a mile
166 WATER: ITS ORIGIN AND USE
of galleries. This stream comes out three-quarters of a
mile further on, through the grotto of Ingleborough.
A hole still deeper than Gaping Ghyll is Rowten Pot
in Kingsdale, described by and first descended by Cuttriss
in July 1897 (Geographical Journal, xiv.). " About 100 feet
from the surface a natural bridge spans the gulley ; while
at 235 feet, after two waterfalls have been passed, the
bottom of the main chasm is reached. Lower down other
waterfalls occur ; while the lowest point of all, 365 feet
below the surface, and more than 20 feet below the bottom
of the valley itself, is reached by winding passages. The
whole undertaking occupied over 14 hours."
These cavities, which are found all over the earth, and
are not at all uncommon, are no doubt formed by the
action of water continually removing soluble matter.
It is to this action that many chemically formed rocks
owe their origin, including travertine, gypsum, siliceous
tufa as deposited by the hot springs, selenite, rock salt,
and many others.
Salt
The formation of salt is essentially the work of water,
by which it has been deposited.
Chloride of sodium (common salt) exists in great
quantities, dissolved in sea-water, in salt springs, and
in the solid deposits of past ages. This last is known as
rock salt. When rock salt is flooded the resulting solu-
tion is termed brine. When common salt is obtained from
sea-water by evaporation it is called bay salt
Under the headings of sea and lakes we shall see how
fresh waters become salt, a process which is going on day
by day through the continual evaporation of the water,
leaving the saline particles behind.
The enormous deposit of marine salt, to which we
SALT 167
shall refer presently, belongs to the Keuper or Saliferous
Period, so named from the salt deposits it contains, which
can only be attributed to the enormous quantities of sea-
water, which, by the convulsions of nature, became separated
from the oceans, then evaporated, again flooded, and yet
again separated and evaporated. Hence the various layers
of salt between alternate layers of clay as we now find them.
What food for thought is here ! All the work of water,
absorbing the saline properties from the soil on which it
has fallen as rain, carrying them into the lakes and sea by
the streams and rivers, where, by the silting up of their
outlets, lagoons are formed ; then the water is evaporated,
leaving behind the salt, which by convulsion and upheaval
is buried and preserved for our use.
Chloride of sodium (common salt) is fortunately one of
the most widely distributed, as well as one of the most
useful and absolutely necessary, of nature's gifts ; and it is
a matter of much comfort to know that this mineral exists
in such enormous quantities that it can never be exhausted.
" Had not," says Dr Buckland, " the beneficent provi-
dence of the Creator laid up these stores of salt within
the bowels of the earth, the distance of inland countries
from the sea would have rendered this article of prime
and daily necessity unattainable to a large proportion of
mankind ; but under the existing dispensation, the
presence of mineral salt, in strata which are dispersed
generally over the interior of our continents and larger
islands, is a source of health and daily enjoyment to the
inhabitants of almost every region."
Even supposing that the whole of the mines, brine pits,
and springs become exhausted, we can fall back on the
sea, whose supply is as boundless as its restless self ; and
there is as little fear of its exhaustion as there is of the
failure of the sun's heat.
168 WATER : ITS ORIGIN AND USE
The salts contained in sea-water, which causes its bitter,
unpleasant taste, form about 3 per cent, of its weight, and
consist principally of common table salt, as will be seen
from the following analysis of the mineral constituents of
sea-water :
Per cent.
Chloride of sodium (common salt) . 75 '786
magnesium . . . 9*159
potassium . . . 3-657
Sulphate of lime (gypsum) . . . 4 '6 17
magnesium (Epsom salts) . 5'597
Bromide of sodium . 1'184
100-000
The residue from evaporated sea- water, after the common
salt has been taken from it, is used in the preparation
of Epsom salts (sulphate of magnesium), Glauber's salt
(sulphate of soda), etc.
Sodium is the metal of which soda is the oxide. It is
more abundant on our globe than any other metal, and
constitutes two-fifths of all sea salt.
Salt-gathering forms one of the oldest of our industries.
For over 1000 years it has been the staple industry of
Droitwich, and it is little wonder that subsidences in the
overlying rocks occur, with streets of tottering houses,
commonly seen in the neighbourhood of these salt-works,
so enormous has been the quantity of the brine pumped
up, and salt obtained.
Where it is found as rock salt, it is purified by dissolv-
ing it in water and then evaporating the solution in
shallow pans by artificial heat, leaving the salt crystals.
Saturated solutions do not boil at 100 C.
Water, when saturated with salt, boils at . . 109 C.
nitre, . . 115'6 C.
potassic carbonate, boils at 140 C.
SALT 169
The temperature at which a saline solution boils will
determine the proportion of salt present.
Generally it may be taken that all salt to be used in
connection with human food is obtained from brine, and
rock salt is the kind generally used for various agricultural
and manufacturing purposes.
The top of the rock salt at North wich is only 130 feet
below the surface, and the deposit varies in thickness to
about 200 feet at Winsford.
The beds in Cheshire and the neighbourhood cover an
area of 20 miles long by 15 miles wide, and the deposit is
estimated at 150 feet thick.
At Hartlepool the salt beds are from 800 to 1600 feet
below the surface. The chances of this salt ever being
required for use are very remote.
Northwich, in Cheshire, provides us with about 1 million
tons of salt per annum. Here, after passing through about
130 feet of soil and rock, we come to a bed of rock salt 75
feet thick, at the base of which there is another bed 30
feet thick ; and beneath this there lies a third bed 90 feet
thick. Here there has been excavated an enormous
chamber, 17 acres in extent and 25 feet high, the roof being
supported by pillars of salt about 10 feet square, at intervals
of about 25 yards.
The principal supply, however, is obtained from brine
springs. About 10,000,000 tons of brine are pumped
annually, from which are obtained over 2,000,000 tons
of salt.
One gallon of Cheshire brine fully saturated yields
2| Ibs. of salt ; while sea-water rarely contains more than
^ lb. This salt is also much purer than salt from
the sea.
In Saxon times a place where salt was dug was called a
" wich" ; hence Droitwich, Nantwich, Northwich, Middle-
170 WATER : ITS ORIGIN AND USE
wich. This fact alone reminds us of the antiquity of the
industry.
The revenue of the salt mines was one of the chief
sources of income to Worcester Cathedral in 816 A.D.,
when Kenulph, king of the Mercians, gave ten houses at
Wich, with the salt furnaces ; and in 906 A.D. five more
were given to this same church.
In the evaporation of brine, if fine table salt is being
obtained, a temperature of 226 F. (the boiling point of
brine) is required. For the manufacture of coarser-grained
salt, called " fish salt," the brine is only heated to 110 F.,
the evaporation being slower. The salt is then deposited
in larger crystals.
In the year 1900, 547,395 tons of salt, valued at
457,340, were exported from Great Britain ; and of the
amount consumed at home it is estimated that at least
200,000 tons are used for manufacturing purposes and
manure ; in the former case for glazing pottery, hardening
soap, and the manufacture of glass.
Salt is also the source of soda and chlorine, and is
largely used for fertilising the soil and for the manufacture
of artificial ice.
In England it is found in great abundance in Cheshire,
Yorkshire, and Worcestershire.
In the Sahara Desert there is an oasis called Bilma,
where it is said that there are large deposits of salt.
On the south-west coast of the Dead Sea is a range of
hills of rock salt 7 miles long, 300 feet high, called
Khashm Usdom, " The Kidge of Sodom."
Large quantities are found in New York, Pennsylvania,
and Wiirtemberg.
The salt mines of Wielicza, in Galicia, Austria, are but
a little depth below the surface.
These are the most celebrated mines in the world, and
SALT 171
have been worked continuously for 600 years. The mass of
salt is calculated to be 500 miles long, 20 miles broad, and
1200 feet thick. The galleries and chambers in this mine
extend to 30 miles, yielding 55,000 tons per annum.
In Cardona (Barcelona) there is a hill of rock salt 500
feet high, the appearance of which in the sunlight is of
dazzling brightness.
Near Kalabagh (India), on the Indus, are hills and cliffs
of solid rock salt which are extensively quarried.
Schonebeck, on the Elbe, is also an important salt-mining
centre.
In Michigan, U.S.A., salt of great purity occurs; the
basin containing the same covers an area of 8000 square
miles.
Salt is produced in large quantities in Ohio, U.S.A. The
brine of the Tuscarawas valley yields 1 Ib. of bromine to
1 barrel of salt. Half the bromine of the world is produced
in Ohio.
In Nevada, U.S.A., we have the salt lakes Walker,
Carson, and Pyramid. Here the mineral abounds, and is of
great purity.
In Eeichenhall (Bavaria) are most important salt-works,
the mineral being obtained from brine springs. Similar
salt springs abound in Jura, east of France, bordering on
Switzerland.
In Gironde (France) salt is obtained from lagoons. In
the south of France we have also Aigues Mortes (dead
waters), a small town near the mouth of the Rhone, where
a considerable amount is obtained from lagoons.
In Anegada, the most northern group of the British West
Indian Islands, salt is obtained from numerous salt ponds.
These few instances will give us some idea of the
universal distribution of salt, and the enormous quantities
in which it is found.
CHAPTER VII
SNOW
SNOWFLAKES
" Out of the bosom of the air,
Out of the cloud-folds of her garment shaken,
Over the woodlands brown and bare,
Over the harvest-fields forsaken,
Silent, and soft, and slow,
Descends the snow."
LONGFELLOW.
WE have, in the preceding chapters, given some atten-
tion to the several forms in which the moisture in
the atmosphere is precipitated, both in its liquid and solid
forms. We have, however, singled out that most beautiful
form, snow, for special consideration.
How Snow is Formed
Snowflakes are assemblages of minute crystals of ice
formed from the aqueous vapour in the atmosphere. As
we ascend from the earth the atmosphere becomes colder,
until freezing point is reached.
The aqueous vapour in the air can no longer be retained
as such, but is condensed and clouds are formed, which
ultimately become ice, in the form of snowflakes.
Snowflakes vary in size from one-fourteenth of an inch
to 1 inch in diameter. The smaller ones are found when
the temperature is very low, but the larger not until it
is near 32 F.
172
SNOW CRYSTALS 173
We frequently hear mention of Protoccus nivalis (red
snow). Darwin mentions having seen it in his passage of
the Cordillera. The footsteps of the mules, he states, were
stained pale red, as if their hoofs had been slightly bloody,
the snow being coloured only where it had thawed very
rapidly, or had been accidentally crushed. A little rubbed
on paper gave it a faint rose tinge. He at first thought it
was dust blown from the surrounding mountains of red
porphyry. This was not so, for the colour is due to the
presence of a genus of algae which appears on the surface
of snow. Extensive tracts, both in the Arctic and Alpine
regions, are in a short time frequently tinged deep crimson
by this minute plant, which consists of groups of microscopic
spheres, in colourless cases, each J-Q^^ part of an inch in
diameter.
Snow Crystals
"From the clouds to earth nature was busy marshalling her
atoms, and putting to shame by the beauty of her structures the
comparative barbarities of art." TYNDALL.
When produced in calm, cold air, these icy particles
form beautiful stellar shapes, each star having six rays.
There is no deviation from this hexagonal shape. The
clear spicules of ice always cross at an angle of 60, usually
forming six rays arranged symmetrically about a centre.
The flakes have great diversities of density and display
innumerable varieties of the most beautiful forms.
As will be seen in the illustration, though they vary in
figure, the six rays are common to all ; it will also give an
idea of the beautiful forms these stellar figures take.
During a fall of snow there will be a strong similarity
in the forms of the crystals, varying with the different
storms ; and we can but admire the inimitable delicacy and
beauty of nature's handiwork in their formation.
174 WATER : ITS ORIGIN AND USE
"Let us imagine," says Professor Tyndall, "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."
He also refers to these beautiful stellar forms in his
account of an ascent of Monte Kosa in 1858 : " Some snow
fell upon my hat ; it 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-leaved type. It was
wonderful to think of, as well as beautiful to behold.
" And thus prodigal nature rained down beauty, and had
done so here for ages unseen by man."
Professor Tyndall draws attention to the fact that snow
crystals differ from ice-flowers ; the former being " crystal-
lised," the latter the result of breaking down or "de-
crystallisation " of the ice.
Transparency of Snow
" As white as snow " is a common expression ; but snow
is colourless ; its apparent whiteness is produced by the
reflection and refraction of light from the minute surfaces
of the crystals.
When a snowflake is examined under a microscope, it
will be found to consist of perfectly clear, transparent ice.
There is no prettier sight in nature than that of a fall
of snow. Every branch and twig, every obstacle it meets in
falling, is enveloped in its feathery flakes : even the trees
bow their heads under the weight of their snowy burden.
Mrs Aubrey Le Blond.
CRYSTALLIZED SNOW.
Mrs Anbrei/ Le Blond.
A STUDY OP SNOW IN DETAIL, TAKEN AT ST MORITZ.
[To face p. 174.
TRANSPARENCY OF SNOW 175
Even in snow animal life exists, for the small worm
Enchytraeus lives in it at the temperature of freezing water.
It is curious, too, that in northern regions nature, in
addition to providing all birds and animals with suitable
covering to protect them against severe climatic conditions,
also, with the advent of the snow, changes their colour to
white as an additional protection from their enemies.
Some, of course, wear their white cloaks all the year round,
as do the Alaskan wild sheep, Polar bear, etc. ; but the
mountain hare, willow grouse, ptarmigan, ermine, Arctic
fox, and many others, change to white only during the
winter.
This interesting phenomenon can be seen in our
Zoological Gardens. An observer referring to this writes,
(28th December 1906) :
" What do the animals in Eegent's Park Gardens think
of an English winter, with its interesting surprises and
absolute uncertainty of mood ? To most of them it is
probably a sore subject. It interferes with the seasonal
changes of colour in many of them.
" The poor little Arctic foxes, for instance, when we had
a cold snap last November, hurriedly began to drop their
fine blue summer suits and get into the white livery they
ought to wear at the year's end. Then it turned warm
when December came, and the change in their fur stopped
responsively, and so went on by fits and starts in a most
inconvenient and unbecoming manner. The weasels, too,
who turn white down to the tips of their tails in winter,
like some of their betters, never know what to wear in the
between-times of English seasons ; and only a few of the
most strong-minded of those who dress according to the
equinoxes are courageous enough to get into cold weather
trim when the proper time comes, whatever may happen
to the thermometer."
176 WATER: ITS ORIGIN AND USE
A curious instance of change in colour has occurred in
one of my own fowls. The bird is one from a brood of a
first cross between a fine strain of Indian game and
Houdans. The chicks were all uniformly black, but during
the first year one of them became speckled black and
white all over, without changing feathers. Next year she
changed to pure white all over, during the summer ; and
now she has once more become spotted black and white in
nearly equal proportions. All the others of the same brood
have remained consistently black.
Snow as a Conductor
Snow is a bad conductor of heat, and is therefore a
suitable substance for use when we wish to resist external
changes of temperature. When snow throws its mantle
over the land it protects vegetation from the cold blasts
of winter and so preserves it. The Esquimaux of Green-
land defy the icy blasts of the Arctic regions by retiring to
huts built of snow and ice.
It is probably not within common knowledge that at
the approach of winter the female Polar bear retires to
some sunny recess among the rocks, but not merely to sleep
through the cold months. The snow covers her com-
pletely many feet deep, leaving no trace of her whereabouts;
but the warmth of her body keeps clear a small space in
which she may move freely, and in this space her young
are born and remain with their mother, protected by a
mantle of snow, until the spring comes and releases them.
A fresh fall of snow from 10 to 12 inches deep, when
melted and measured in a rain-gauge, has been found by
the writer to yield a quantity of water equal to a fall of
1 inch of rain. This confirms the results given by others
who have made similar tests.
IMPURITY OF SNOW 177
The water derived from old snow, however, is consider-
ably more. Sometimes 4 inches of old snow will yield
1 inch of water.
It is found that snow of average density offers four times
greater resistance to external changes of temperature than
does ice of equal thickness, and that independently of its
peculiar property of retaining radiant heat. This affords
a measure of the protective power of a snow- covering to
the surface on which it rests.
The comparison of the thickness of the snow-covering
with the amount of precipitation gives as a mean result
10 inches snow = 1 inch rain. The temperature observa-
tions show that while the minimum temperature on the
surface of the earth, under a thin layer of snow, is con-
siderably lower than that of the air, on account of
radiation, the snow is in general warmer than the air ;
and that while a thin coating of snow reduces the
temperature of the soil at the surface, a covering of 12
to 16 inches thick affords great protection.
It has been ascertained by experiment that during the
whole winter the temperature 4 inches below the surface
of the snow-covered soil never fell to the freezing point,
while on ground kept clear of snow it was below freez-
ing from 31st January to 1st April at a depth of
19 inches.
The specific gravity of newly fallen snow ranges from
0'038 at low temperature to 0*161 under humid conditions ;
and on a hard crust being formed by melting it, it rises to
0-489.
Impurity of Snow
The benefits we derive from a fall of snow are far
greater than we casually imagine. It has been called
" health-giving snow," and such it is. Its purifying effect
12
178 WATER: ITS ORIGIN AND USE
upon the air as it falls is said to be greater than if the
same quantity had fallen in the form of rain.
" Probably," says the Lancet, " when the snowflakes
are absolutely dry, they would fall to earth practically
unsullied by atmospheric impurities. It is rarely, how-
ever, that snow is quite dry, and thus it presents a more
or less moist surface to both the soluble and suspended
impurities of the air, and so carries them to the earth.
The action as regards impurities may be compared with the
clarifying effect of a fine, insoluble powder, which, when
thrown into impure water, gradually subsides, carrying
with it a large amount of the impurities. The process in
natural waters is known as purification by sedimentation.
Snow, of course, is colder than rain, and hence would have
a greater dissolving capacity for gases, since these are more
soluble in cold than in warm menstrua. Tradition has it
that after a fall of snow men feel stronger, owing to the
exhilarating effects of the snow-swept air. Science, at all
events, cannot quarrel with this conclusion, inasmuch as
it is easily demonstrable that the air is purer and sweeter
after a fall of snow."
Exercise in the snow is remarkably bracing, as is seen
in the glow of health invariably shown on the faces of those
who sleigh, ski, toboggan, or skate, or whose pastime is
the simple one of snowballing. Apart, however, from the
removal of impurities by snow, there is some reason for
believing that the vital qualities of air are intensified by
some obscure action of the snow on the oxygen of the air,
forming perhaps ozone, or even oxygenated water, as per-
oxide of hydrogen is sometimes called. Snow-swept air,
at all events, especially if it be dry, readily responds to
the ozone test paper, and the peculiar " metallic " smell of
the air after a heavy snowfall is doubtless due to ozone or
a closely related substance. That the heavy fall of snow
12,000 FEET ABOVE THE SEA.
OFF TOWARDS THE MATTERHORN.
Mrs Aubrey Le Blond.
A CORNICED RIDGE OX AN ENGADINE PEAK.
[To face p. 178.
SNOW-LINE 179
which took place in the early hours of the day after
Christmas Day 1906, removed a great mass of impurity
from the air in London, is plainly indicated in the results
of an analysis which was made of the snow taken from
the roof of the Lancet offices. The results of the analysis
of the clear snow-water were as follows :
Grains per gallon.
London. Kent.
Free ammonia .... 0-067 0'030
Organic ammonia . . . 0'039 Nil.
Nitrates and nitrites . . . Nil. Nil.
Chlorine 0-840 0-630
Common salt .... 1'400 1-030
Sulphuric acid .... 1-730 Nil.
Total solid matters . . . 5'60 1'68
Tarry compounds . . . 1-40 Traces
Hundreds of tons of these impurities tar, ammonia,
and sulphur must therefore have been brought to earth
in London by that snowstorm. The second analysis refers
to snow which fell at the same time, but on the lawn of a
country garden in Kent, some twelve miles south of the
Metropolis (Daily Telegraph, 5th Jan. 1907).
Snow-Line
" Mont Blanc is the monarch of mountains,
They crowned him long ago,
On a throne of rocks, in a robe of clouds,
With a diadem of snow."
BYRON (Manfred).
Snow-line is the limit of perpetual snow, or the line
above which mountains are perpetually covered by snow.
Here the snow may evaporate or the sun's rays may melt
some of it, but the cloak of snow never disappears. The
mountain Kilimanjaro, in Africa, is 19,400 feet high ; and
though it is but three degrees from the Equator, it keeps
180 WATER: ITS ORIGIN AND USE
its white crown of snow continually, in spite of the
tropical sun.
If we travel towards the Pole, the snow-line gradually
lowers, until in the chilly Polar regions it is at the sea-
level ; and here we find the perpetual snow- and ice-fields.
In England the freezing point is in summer 1J miles
from the ground, but in winter the level at which snow is
formed often comes down to the surface of the earth.
Many mountains only thrust their heads a little way
into the cold regions, and get but a small accumulation of
snow in the winter, which generally disappears during the
summer : such mountains are therefore said to be below
the snow-line.
The distance down a mountain that the snow reaches
varies with the seasons.
On the Swiss mountains the snow-line is 8500 feet
above sea-level; in the Caucasus 14,000 feet; the Hima-
layas 16,000 feet to 19,000 feet; at Spitzbergen only
1500 feet.
On the Himalayas the snow-line is from three to four
thousand feet higher on the north side than on the south,
notwithstanding that this side is nearer the Equator ; but
the winds that blow upon the south side have passed
over the Indian Ocean and are heavily charged with
moisture, which is deposited on the southern slopes in
the form of snow, while the snow-line on the north side
is raised by the hot, dry winds which blow across the
plains of Thibet.
As we have seen, the snow-line is subject to slight
variation from local circumstances ; outside these considera-
tions it depends primarily upon the latitude. Though it
may vary from year to year, if an average of many seasons
be taken it is tolerably uniform, and varies from the
heights given down to nothing ; for, as we travel towards
SNOWFIELDS 181
the Poles, the snow-line gradually lowers until it reaches
sea-level.
Mountain snow would accumulate to an enormous thick-
ness were it not for the annual melting and the quantity
which disappears in the form of glaciers and avalanches,
and, last but not least, by continual evaporation ; for snow
evaporates even above the snow-line, with the temperature
continually below freezing point.
" One very long, dry summer," writes Darwin, " all the
snow disappeared from Aconcagua (Central Chili), although
it attains the prodigious height of 23,000 feet." And he
concludes that it evaporated rather than thawed.
Snowfields
There are permanent fields of snow found on the tops of
mountain ranges above the snow-line.
" These vast piles of snow," says Darwin, " which never
melt, and seem destined to last as long as the world holds
together, present a noble and even sublime spectacle."
The snowfields of Norway are numerous ; one, Inste-
dalsbrae,is 580 square miles in area, and reaches an altitude
of 5000 feet, sending off numerous glaciers.
The temperature here in the land of mountain sriow is
different from the cold experienced in the Arctic regions ;
in the former regions the intense solar radiation by day
raises the surface when dry to a temperature of 80 F.,
alternating with nights of severe frost.
Half-way up the Alps the mean temperature has been
found to average 32 F., a height which in snowy regions
is never reached.
Even where the temperature is lowest, the solar radia-
tion by rocks and snow is very great, frequently over
120 F. being recorded.
182 WATER: ITS ORIGIN AND USE
Professor Tyndall describes his experience on Monte
Rosa as follows : " There was not a breath of air stirring,
and, though we stood ankle-deep in snow, the heat sur-
passed 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."
On the Himalayas, at an altitude of 15,000 feet, the
variation of the temperature in twelve hours (noon to mid-
night) shows an enormous range. A solar temperature of
157 (32 below boiling point at this altitude) was re-
gistered, and at midnight the thermometer fell to 24.
Among the Nun Kun Peaks, at an altitude of 21,300
feet, about 2.30 P.M., the sun reading of a black-bulb ther-
mometer was 192 F. There was a misty atmosphere,
and the heat was only rendered bearable by wrapping wet
towels round the head. At 4.30 the shade reading was 60
F. When the sun set at seven o'clock, the temperature
fell at once to freezing point, and at nine was nearly zero.
In the Arctic Circle the snowfields are of enormous
area and hundreds of feet in depth ; they are continually
receiving fresh accumulations of snow, which would go on
indefinitely but for the reasons stated.
Here we find a low, equable temperature is maintained,
rarely rising more than a few degrees above the freezing
point. The snow melts to some slight extent during the
heat of the summer day, and evaporates to a still greater
extent : the snow that remains is granular, owing to the
water trickling into its mass and freezing round the
crystals.
This alternate freezing and thawing year after year
causes the snow to become stratified, the different layers
being divided by dirt lines, each of which indicates the
previous year's snow, on which the wind has deposited
dust, leaves, insects, etc.
AVALANCHES 183
This granular mass is the ne*v or firn ; it is not ice, but
the beginning of the ice-river or glacier.
Avalanches
Avalanches are large masses of snow or ice detached by
heat, etc. , from the mountains. They usually occur after
a heavy fall of snow in still weather, which enables the
snow to collect on the steep sides of the mountain, where,
under more boisterous conditions, it would not remain
sufficiently long to accumulate ; it then overbalances by
its own weight, or, loosened by the warm sun, without
warning, slides down, bearing with it rocks, trees, etc.,
overwhelming everything in its path. Valley streams
then carry the debris down to the lakes, or on to the sea.
In this way the mountain summits mingle with the
sediment eroded from the valleys.
It is found that if the rocks lie at an angle of 60, very
little snow can accumulate, and this is soon removed by
the wind.
It is because of the perpetual danger from avalanches
that many of the beautiful valleys in the mountain regions
remain unpeopled.
In 1820, 64 persons were killed in the Engadine (at
Fettan), and 400 cattle and 23 persons at Brieg in the same
year.
This is only typical of what is continually happening in
these snowy regions, and I would refer the reader to the
Adventures on the Hoof of the World, by Mrs Aubrey le
Blond, for a graphic description of the sufferings of a family
who were buried for a month under an avalanche.
Periodically great devastation is caused by the mighty
snow-slips : villages are entirely buried, and forests
destroyed.
184 WATER: ITS ORIGIN AND USE
The sliding avalanches, caused by the melting of the
snow nearest the ground detaching the mass from the bed
on which it rests, move slowly at first, eventually carrying
all before them. These usually occur in the spring of the
year : they differ from the loose snow avalanches which are
common in the winter, and are the least dangerous.
Avalanches of ice and frozen snow, detached from glaciers
by the summer heat, are more serious, and are also of
common occurrence.
The velocity of these frozen masses is enormous, and one
has been known to descend with such momentum that it
ascended 400 feet on the opposite side of the valley.
It is no uncommon thing for an avalanche of snow and
ice to dam up rivers, the water eventually finding its way
underneath, and the avalanche forming a bridge of ice
which sometimes remains many months before completely
disappearing.
In some instances the damage done to life and property
by the wind set up by the rush of the avalanche exceeds
that done by the actual mass of snow ; and by this means
alone, buildings, trees, cattle, and human beings have been
destroyed. One would scarcely believe that the displace-
ment of the atmosphere from this cause could form such
violent artificial tornadoes, with such serious results.
It is said that the vibration of a single voice is at times
sufficient to start a catastrophe of this kind, and that in
some parts the guides insist on perfect silence. It seems
indeed terrible that a single exclamation may possibly
cause the death of a whole party of tourists.
Avalanches consisting partly of snow, ice, and stones,
including huge boulders, are at times hurled down the
mountains with great fury, sending clouds of ice-dust high
into the air, covering the ground with rough angular
stones, fragments of the towering peaks displaced by frost.
Mrs Aubrey Le Klond
THE REMAINS OF AN AVALANCHE
Mi-x Anhre>/ Le Blond.
A TRAIN STUCK FAST IN AN AVALANCHE OX ROCHER DE NAYE.
[To face p. 184.
FLOODS 185
Floods
Floods are often caused by the sudden melting of the
snow on the mountains, owing to a rise in the temperature,
when the water rushes down, as in the case of the Ganges,
where in the spring the water from the Himalayas over-
flows and floods the surrounding plains, at times to a great
depth.
Some of our rivers overflow their banks and flood the
surrounding country for miles, from the same cause, or
from an unusually heavy and continuous rainfall. The
Thames, for instance, has been in a state of flood several
times within the last few years.
Floods are also caused by the bursting of natural reser-
voirs. The great flood of the Dranse de Bagnes in 1818
was due to the outburst of the lake, which had been
dammed back by the glacier Gretroz.
A great portion of Egypt is flooded each autumn by the
river Nile ; but in this instance it is not a catastrophe, for
the greater the flood the greater the prosperity.
The Danube overflowed in 1877, rendering 12,000
persons homeless. The floods of the Loire did damage to
the amount of 8,000,000 in the year 1856.
Innumerable instances of similar catastrophes could be
given, but bearing in mind only those caused by the
melting of the snow, with which this chapter is principally
concerned, it is surely something little short of marvel-
lous, that the pretty feathery snowflake, by its accumula-
tion, should be capable of forming such sublime sights,
and causing, unfortunately, such devastating havoc and
loss of life.
CHAPTER VIII
ICE
From sunward rocks the icicle's faint drop,
By lonely riverside, is heard, at times,
To break the silence deep ; for now the stream
Is mute, or faintly gurgles far below
Its frozen ceiling ; silent stands the mill,
The wheel immovable and shod with ice.
JAMES GBAHAME.
THE properties of ice are most interesting, and will repay
us for the time spent in their study.
Freezing, congelation, or solidification, is the transforma-
tion of a liquid into a solid or non-elastic fluid (so termed
as possessing but little elasticity under the influence of
cold), a fluid being a body whose particles, on the slightest
pressure, move and change their relative positions, with-
out separation ; therefore ice is the crystalline form assumed
by water when exposed to a sufficiently low temperature.
In again melting into water, it occupies just 91 '675 per
cent, of its volume in the solid state, it having expanded
in the process of freezing, the density of ice compared with
that of water at C. being '92.
Each liquid always solidifies at a constant temperature
under the same conditions, which is called its freezing
point, and the solids melt again at the same temperature.
Formation of lee
Fresh water continues to contract with the cold until a
temperature of 39 '2 is attained (its maximum density),
186
Mrs Aubrey Le Blond
AN AVALANCHE BLOCKING A STREAM.
Mrs Aubrey Le Blond.
A TUNNEL 300 FEET LONG CUT THROUGH AN AVALANCHE.
[To face p. 186.
FORMATION OF ICE 187
when the reverse action commences, and continues until
32 is reached. This has already been referred to, but will
bear repetition here.
Water shares this peculiarity with few other substances,
as iron, bismuth, and antimony, each of which requires
more room in the solid condition than in the liquid, for
solid iron floats on molten iron as ice floats on water.
Silver thaw, sometimes called "glazed frost" or "icy
night," is an interesting form.of ice ; it is neither hail, hoar-
frost, nor snow, but rain, each drop of which solidifies as it
touches any solid body, forming small flattened pastilles
of ice. It usually occurs after a severe frost at the be-
ginning of a thaw, and is formed by a damp, warm air
passing over grounds of low temperature, depositing its
moisture in the solid form on any object on which it may
falL This occurred in London on 22nd January 1867,
when many serious accidents occurred owing to the glassy,
slippery state of the ground. It also occurred in a more
severe form in France (Loiret), 21st to 22nd January 1897,
when it accumulated to such an extent on the branches
of the trees as to snap them off at the base, split
them from top to bottom, or bear them over and
uproot them.
Ice also exists in the form of minute needles or spiculae
in the higher atmosphere : the enormous height at which
some clouds float, and the temperature encountered, make
it impossible that they can consist of water, and it is
through the refracted light of these banks of minute ice
particles, when we look at either luminary, we see the
formation of haloes and other similar phenomena which
are only possible when the light has passed through prisms
of ice.
Artificial freezing is attained by the liquefaction of
solids or the evaporation of liquids. These processes
188 WATER: ITS ORIGIN AND USE
absorb heat, and, by abstracting it from the surrounding
substances, freeze the latter.
There are also many freezing mixtures : for instance, 2
parts pounded ice or fresh snow and 1 part common salt
will cause the thermometer to fall to 4 F.; 3 parts snow
with 4 parts of crystallised chloride of calcium produce
54 F. With a mixture of liquid nitrous oxide and
carbon disulphide a temperature of 220 F. is reached.
lee-Flowers
Ice, like snow, forms six-rayed stars.
If a piece of ice be placed in the path of a sunbeam, the
passage of the light through the ice will be marked by a
number of glittering points, each of which, when examined
under a lens, will be found to consist of perfectly formed
six-rayed stars, called ice-flowers ; they consist of little
cavities filled with water, formed by the melting of a
single ice crystal.
Huxley tells us that these beautiful forms, which
commonly resemble blossoms, with six petals or floral
leaves, are not solid crystals, like the crystals of snow,
but are simply hollow spaces of regular shape filled with
water; they may indeed be called "negative" or "inverse
crystals."
Tyndall refers to this as being "the reversal of the
process of crystallisation. The searching solar beam is
delicate enough to take the molecules down without
deranging the order of their architecture."
Unfortunately, few of us have seen these pretty stars or
flowers.
Who can but admire the familiar ice-ferns and flowers
we see formed by the frozen moisture on our windows in
the winter ?
Airs Aubrey Le Blond.
AN AVALANCHE GULLY IN ARCTIC NORWAY.
Mrs Aubrey Le Blond.
AN ICE-CAVE IN THE MORTERATSCH GLACIER.
[To face p. 188.
ICE-FLOWERS 189
Although they are of countless designs, it is found that
the angle between the little shoots and branches is the
same as that between the rays of the star in the snow-
flake, or the petals of the ice-flower, viz. 60.
I wish that my readers would, when the occasion
presents itself, watch the process of the formation of these
ice-pictures; and if no opportunity be found naturally,
they may be produced artificially in a small room the
bath-room for convenience. By means of hot water
saturate the air with moisture, until it streams down the
window; then shut off the source of heat and keep the
door closed ; for the dry air will carry away the moisture,
and prevent the display. The room will quickly cool, and
if the temperature out of doors be low enough, the crystals
will soon form, and can be seen, commencing at the edges
of the pane, as crystal after crystal forms and joins with
others, visibly extending their fantastic figures until the
whole pane is covered.
These feathery pictures are admirably described by
Hannah F. Gould in lines entitled The Frost :
" He went to the windows of those who slept,
And over each pane like a fairy crept,
Wherever he breathed, wherever he stept,
By the light of the morn were seen
Most beautiful things ; there were flowers and trees ;
There were bevies of birds, and swarms of bees ;
There were cities ; with temples and towns ; and these
All pictured in silver sheen."
Keferring to the formation of ice, Tyndall writes : " The
deeper glacier pools are shaded in part by their icy banks,
and through the shadowed water needles of ice are already
darting ; all day long the molecules had been kept asunder
by the antagonistic heat : their enemy is now withdrawn,
and they lock themselves together in crystalline embrace,"
I give this extract with a definite reason. If the reader
190 WATER: ITS OKIGIN AND USE
would like to see these serrated blades of transparent ice,
of every conceivable form, he has but to put a glass vessel
in the way of a sharp, freezing current of air, and they will
quickly form.
I once saw, in my aquarium, lace-like spears of ice
spreading in fan-like form across the aquarium in all
directions ; and through them the fishes threaded their
way, as if wondering what change had come over their
home.
This was probably caused by a freezing current of air
striking the glass at various points, and it would eventually
have congealed the whole mass and burst the tank, had
the temperature not been raised.
Expansion and Pressure
We have previously stated that, by reason of expansion,
a piece of ice weighs less than an equal bulk of water. A
certain bulk of water will weigh 1000 Ibs., and a piece of
ice of similar bulk will only weigh 916 Ibs. ; hence it floats
with about only one-tenth of its volume above water. It
is a fact that ice always melts at 32 F., and is but slightly
influenced by pressure, to the extent only of 0*00757 C.,
for each additional atmosphere.
If water be put under pressure, it takes a greater amount
of cold to solidify it ; should the pressure be removed, it
will immediately congeal, and expand in the process.
The pressure required to prevent water from freezing
at 30 is 138 tons to the square inch, and so on in pro-
portion to the temperature.
Therefore, our water-pipes, that give so much trouble to
the householder in winter, and are such a source of work
and profit to the plumber at the same time, have no alter-
native but to burst their sides with the expansion caused
191
by freezing. Even if made strong enough to resist 138
tons to the square inch, they would only be able to resist 2
of frost ; 3 of frost would still cause them to burst.
Heat given out by Freezing
There does not appear to be much logic about this, and
to the uninitiated it appears at least curious or doubtful ;
but it is a fact.
The very freezing of water gives out heat. Any body,
in solidifying from the liquid state, gives up a quantity of
heat without exhibiting a decrease of temperature, and the
amount of heat given out by a pound of water as it freezes,
would suffice to raise it to 140 F. If the reader was able
to follow the explanation of "latent heat" previously
referred to, he will have no trouble in understanding
how these conditions arise.
Therefore, to put it shortly, the quantity of heat
absorbed or liberated in melting ice or freezing water is
sufficient to raise the temperature of seventy-nine times
its weight from C. to 1 C.
It is this singular property of water which greatly
mitigates the cold of the Arctic and sub-Arctic regions.
The cold is expended in freezing the water, not in lower-
ing the temperature still further.
The absorbing or liberating (as the case may be) of heat
or energy by freezing or melting, by condensation or
evaporation, goes on continuously ; whether it be in
evaporation from the bosom of the tropical seas, the
mighty snowfields, or the never-idle glaciers, or from the
domestic kettle.
The old saying, " It will be warmer after the shower,"
is founded on experience ; for the heat absorbed in the
evaporation and formation of the vapour in the atmosphere,
192 WATER: ITS ORIGIN AND USE
reducing the temperature of the latter, is given out when
the vapour is condensed into rain, causing a rise of
temperature.
Before leaving this subject, it will be of interest to many
to know a little of the action of heat on ice.
We have in previous chapters seen the effect of heat
upon water and ice from 32 F. upwards. The reader
will probably wonder what effect it has on ice at F.
" Suppose radiant heat," says Dr Mill, " be supplied to
1 Ib. of ice at F. Each unit of heat raises the tempera-
ture of the mass by 2 (hence the capacity for heat of ice
is only half that of water), and by the time 16 units of
heat have been absorbed, the mass of ice has expanded
considerably and its particles are vibrating with increased
energy, so that the temperature is 32."
Freezing of Lakes
We have but to remember the increase in volume of
water when freezing, and we shall see how miraculously
nature does her work ; and then imagine, if we can, what
would happen to the world and to us, if the contraction
with cooling of water continued throughout the scale of
the thermometer from 39'2 F. downwards : there would
simply be no life on the earth. Let us take the freezing
of a lake, and see what happens.
The surface of a lake cools down as winter approaches,
the water at the surface, being heavier, sinks, and the
warmer water from the bottom rises to take its place.
This circulation goes on as long as the surface continues
to cool, but when the whole of the water in the lake has
reached a temperature of 40 F., the surface-water, if
further cooled, becomes lighter and remains on the top,
and, should the cold be severe enough to reduce the water
FREEZING POINT OF SEA- WATER 193
to 32, a thin layer of ice will be formed over compara-
tively warm water.
This preserves the animal life in the water and forms a
barrier of protection to the water underneath, from the
cold ; were it not for this peculiarity, the lakes, etc.,
would be converted into a mass of solid ice.
"If ice had been heavier than water, the sea-bottom
in higher latitudes would have been covered with solid
crystal, till finally the whole sea, to far within the
temperate zone, would have formed one solid mass of ice.
The sun would have been as powerless to melt this pro-
digious body as it is to dissolve the glaciers of the Alps, and
the cold radiating from its surface would have rendered
all the neighbouring lands uninhabitable" (Hartwig).
Freezing Point of Sea- Water
Sea-water is heavier than fresh water, owing to the salt
it contains, and requires a temperature of about 2 C.
to freeze it.
The Greenland ocean does not freeze until a temperature
of 26 F. to 31 K, according to its saltness, is reached, or
about 3 lower than fresh water.
When concentrated till its specific gravity reaches
1*1045, sea- water requires a temperature to freeze it of
18J lower than fresh water. Even then the crystallising
force rejects four-fifths of the salt, and freezes the water
alone, with the result that the ice of sea- water, when melted,
produces fresh water. But this fresh water tastes bitter
and unpleasant, for it still contains some salt which was
entangled mechanically in the spaces between the ice-
crystals.
If a mixture of sulphuric acid and water be frozen, a
similar result is obtained, for the ice is pure and free from
acidity.
13
194 WATER: ITS ORIGIN AND USE
Ground, Bottom, OF Anchor lee
In addition to the ice formed on the surface of water, it
forms also at the bottom of rivers and seas where con-
ditions are suitable, and remains there for some time.
This curious phenomenon, the formation of ice at the
bottom of the sea, is apparently in direct opposition to
all theory in reference to the increase in bulk of ice
from that of water, or the relation between the densities
of water in its solid and liquid states.
Bottom-freezing occurs in the Cattegat, the Baltic, in
the Polar seas, in shallow water near land, and off the
coast of Labrador, etc., where ice forms at considerable
depths ; it has been found that seals caught in the lines
at those depths are at times frozen solid.
Darwin states that " in the shallow sea on the Arctic
coast of America the bottom freezes, and does not thaw
in the spring so soon as the surface of the land."
The surface of the sea, previously clear, has been within
half an hour or so covered with bottom ice, so as to be im-
passable by boats.
The ice forms in plates, coming to the surface edgeways,
with such force as to raise the upper edges several inches
out of the water.
Its formation is accounted for in the following manner :
although no lower temperature can be carried down
by the water than that to which it has been subjected at
the surface, the water that does not freeze at, say, 2'5
C. when lying upon the surface, changes into ice when
it comes in contact with the irregular bottom, prob-
ably through the more ready dissipation of the heat
set free in the act of congelation, and is retained for a
time by the cohesion between it and the stones of the river
bed ; when at last it is forcibly released from this contact,
ICE-FIELDS 195
it rises to the surface, bringing with it stones, rocks,
chains, etc.
lee-Fields
Vast fields of ice of enormous extent and thickness are
formed in Polar latitudes every winter, but are broken up
in the summer by heat and the force of the waves ; drift-
ing, by the aid of wind and ocean currents, they become
piled into dangerous heaps, forming a menace to the navi-
gation of ships in Polar seas.
The ice-fields of Iceland are of large area. The prin-
cipal, " Vatnajokull," covers 4000 square miles.
The average thickness of sea ice is about 8 feet. Some
writers affirm that, if undisturbed by heat and waves, it
will attain a thickness of 18 feet.
It is stated that a sheet of ice 1 inch thick will
support a man, 4 inches thick will support cavalry, 5
inches thick will support 84-lb. cannon, 10 inches thick
a multitude, and 18 inches thick will support a train.
During the war between Eussia and Japan, this method
of transit over Lake Baikal was resorted to ; this large
fresh-water lake is in Eastern Siberia, and is about 360
miles long, with a maximum breadth of 50 miles and
maximum depth of 400 feet.
Where sheets or fields of ice from 30 to 100 feet thick
are met with, they have been formed by the sheets being
forced one over another.
The ice-fields of Greenland are beyond our comprehen-
sion : how high the plateau rises we cannot say. Greenland
is 1400 miles long and 900 miles broad. No man has yet
penetrated more than 130 miles from the coast on the
west side, where the ice is nearer the sea. It is related
that explorers, after travelling 130 miles, saw a solid wall
of ice 6000 feet high, and rising towards the east. This has
196 WATER: ITS ORIGIN AND USE
been doubted, and is probably exaggerated, but from other
observations there seems to be no doubt that it attains at
least a thickness of 3000 feet. Here in June and July
the sun is constantly above the horizon : this short summer
is followed by a long and dreary winter.
The interior, which is lofty, and has the appearance of
being one vast glacier, is uninhabitable ; the tongues of
ice, 2000 to 3000 feet in thickness and over 50 miles in
width, steal down the valleys and push far out to sea,
breaking up and forming the dreaded icebergs.
Polar Expeditions
Considering the important part these regions of snow
and ice take, more particularly the effect produced on the
sea and the atmosphere of the world generally by the cold
counter-currents issuing from them, which influences the
climate, a few brief particulars of some of the Polar expedi-
tions may be of interest.
Expeditions of discovery into these regions, both north
and south, have long had a fascination for man.
In 1517 Sebastian Cabot searched for a north-west
passage round America to India. In 1850 M'Clure
attempted a similar task, discovering a passage from the
Atlantic to the Pacific, which he named the Prince of
Wales Strait. Becoming imprisoned in the ice at Melville
Sound, his further progress was prevented, and here he was
rescued by M'Clintock.
The voyage through this North- West Passage has only
lately been accomplished by that redoubtable sailor Cap-
tain Amundsen, who sailed from Christiania in the small
ship called the Gjoa on 16th June 1903. His voyage of
adventure occupied three years, during which period, to
use his own words, " the earliest dream of his childhood
Mrs Aubrey Le Blond.
No. 4. DETAIL OF PETALS OF THE ICE-FLOWERS.
Mrs Aubrey Le Blond.
No. 5. THE ICE-FLOWERS MEET WITH AN UNTIMELY END.
[To face p. 196.
POLAR EXPEDITIONS 197
was realised." In his small craft he had accomplished
the North- West Passage, a task fraught with many tragic
memories of previous aspirants for the honour ; for which
Captain Amundsen received the gold medal of the Royal
Geographical Society.
Since Cabot's time frequent attempts have been made
to lessen the distance between the known and unknown in
both the Arctic and Antarctic regions.
Of those attempting to reach the North Pole, space will
but admit of the mention of such names as Frobisher,
Davis, Bylot, and Baffin ; then, after a lapse of effort for
about two centuries, came Eoss and Parry in 1818,
followed by the fateful Franklin expedition, which set out
for the northern region in May 1845.
Numerous expeditions went in search of the missing
explorer, and at length, in 1853, Rae, and in 1855
Anderson, discovered relics of the Erebus and Terror ;
M'Clintock, however (1857-9), established the fact that
the Sir John Franklin expedition ceased to exist in 1847.
The writer recalls with pleasure the frequent stirring
descriptions of M'Clintock's expedition that were given
him by one of the party, with whom he was most
intimate ; the old sailor, with his snow-white hair, took a
never-tiring delight in relating his experiences, and would
proudly show the relics brought home, some being from
the actual lost expedition ; and the pride with which he
would produce the watch presented by Lady Franklin,
made no little impression on the writer. The good old man,
alas ! left these shores for a calmer port some years ago.
Since the above we have the names of Nares (1875),
Greely (1881-4), who reached the then farthest north,
viz. 83 24'. In 1888 Nansen beat all previous records,
approaching within 260 miles of the North Pole. This has,
however, been eclipsed by Peary, who reached 87 N. lat.
198 WATER: ITS ORIGIN AND USE
on 21st April 1906, or only about 200 miles from the Pole.
Here, however, unlike the South Polar explorers, he could
replenish his larder with musk oxen, reindeer, seal, walrus,
hares, and fish from Lake Hazen. Notwithstanding these
luxuries, the privations and sufferings of the explorers
were great, and the risk of life can only be appreciated by
reading the published accounts of the expedition.
Not less interesting are the accounts of those who have
endeavoured to pierce the Arctic region, in trying to
discover the North-East Passage, along the northern
coasts of Europe and Asia to the Pacific ; this attempt, like
all these expeditions, resulted in much suffering and loss
of life, for it will be remembered that Henry Hudson, dis-
coverer (in 1610) of the bay or strait bearing his name,
was put by his mutinous crew into an open boat with his
son John, and several of the most infirm of the sailors,
and cast adrift in these awful regions, never to be heard of
again : an action that needs no remark !
Frequent attempts were made during three centuries to
discover this North-East Passage, and it was at length ac-
complished (1878-9) by a Swedish explorer, Nordenskjold.
The first to discover land in the Antarctic Circle was
the Dutch navigator Dirk Cherrits, who was unwittingly
driven southward to lat. 64.
Cook was the first explorer to pass the 70th parallel, in
1772, reaching 71 10' on 30th January 1774.
All attempts at the exploration of the South Pole have,
up to the present time, been frustrated by an insurmount-
able barrier of ice.
Sail southward, and you will come to an ice wall 50 to
400 feet high ; as far as the eye can reach, there is nothing
but snow and ice.
Captain R. F. Scott describes it as " forming a frowning
obstacle 400 miles at least in length ; it is a solid wall of
POLAR EXPEDITIONS 199
ice, which nothing can penetrate or dislodge; here and
there the sea has eaten into its sides deep and treacherous
caves."
This region of desolation is without animal or vegetable
life, its cliffs of solid ice reaching to the sea.
Eoss was the first to penetrate the ice-pack, in 1841-2 ;
reaching 78'10, he sailed eastward along this marvellous
wall of ice (which was described as being 1000 feet thick)
for a distance of 450 miles, and found it without a
break.
He was the first man to gaze on this mighty " ice-wall,"
which he rightly christened " The Great Ice Barrier," for
it is truly a barrier; he saw only the face of the huge
" Ice Cap " which covers the whole of the South Polar
regions.
In 1899, Mr Borchgrevink reached 78*50 and located
the South Magnetic Pole. Many other expeditions have
also entered these regions.
Captain Scott, however, has the honour of penetrating
farthest into these regions ; by the means afforded by one
of the rivers of ice, the " Ferrar Glacier," he was able to
ascend to the surface of the Ice Cap. Here his party was
greeted by bitter, cutting, blinding winds, and after
suffering great privation, on 30th November 1903 they
stood where never yet man had been, in the heart of the
ice wilderness of " Victoria Land," lat. 82 17', about 600
miles from the South Pole.
Glaciers of the valley or Alpine type are found in the
Antarctic on the most stupendous scale. One mentioned
by Eoss, as being on the east coast of Victoria Land, fills
a valley bordered by mountains 6000 to 10,000 feet high,
sending a tongue of ice far out into the sea.
The reports as to the Southern Ice Cap are very con-
flicting.
200 WATER: ITS ORIGIN AND USE
Mr Croll estimated the accumulation of the ice and
snow at the South Pole as being 10 to 20 miles thick, but
recent investigation into the properties of ice, the relation
of its melting or freezing point to the temperature and
pressure, shows that this is impossible.
If the Ice Cap rests on rocks of a temperature half a
degree below the freezing point, then the greatest thickness
of the ice formed on the continent would not be likely to
exceed 1600 or 1800 feet: this is just a little more than
the greatest thickness of the Great Ice Barrier, when it is
floated off into the ocean as ice islands or bergs.
This great glacier or Ice Cap of the Antarctic is described
by Murray in the Geographical Journal as being pushed
out all over the low lands into the ocean, forming there
the true Ice Barrier, a solid perpendicular wall of ice,
probably from 1200 feet to 1500 feet in thickness, rising
from 150 to 200 feet above, and sinking 1100 to 1400
feet below the level of the sea. When the forefronts
of this great creeping glacier are pushed into the depths
of 300 or 400 fathoms, large stretches are broken off and
float away, giving birth to enormous icebergs.
It is stated that this ice cap has a movement of about
100 feet a month.
In these regions (Antarctic) Captain Scott, at a distance
of 142 miles inland, had reached an altitude of 9000 feet,
travelling miles over clear blue glacier ice.
Captain Scott, in an address delivered before the Royal
Geographical Society, stated that the great Southern Ice
Cap of to-day is but a remnant of what existed at a former
period of glaciation, and concluded that a great glacial
epoch was the result of a comparatively mild climate ;
he also expressed a belief that this mighty ice barrier is
really afloat, but this is open to doubt.
That this great ice barrier is receding, in common with
ICEBERGS 201
the European and American glaciers, is accepted by
scientific men. These facts, as well as the regular re-
currence of famines in Eussia and other most fertile
districts, point to the same cause the presence of less
moisture in the atmosphere.
Icebergs
As we have already seen, icebergs are the offspring of
the Polar glaciers, which are forced continually downwards
into the sea, and detach themselves in enormous masses.
Some of these rise hundreds of feet out of the water. It
must also be remembered that the specific gravity of ice com-
pared with sea-water is about as '920 is to T026, varying
with the density of the ice and the saltness of the sea, and
it is variously estimated that the weight of the ice sub-
merged is from eight to fourteen times that of the portion
appearing above the surface.
Another authority gives the different densities of ice
and sea-water as '92 and 1'03 respectively, so we may
conclude that only ^3- or about one-ninth of the iceberg
appears above water.
Another authority states that a floating iceberg will
have 89 - 6 per cent, of its volume immersed, if it has the
same temperature and consistency throughout.
The upper layers of these ice-islands are much less dense
than the deep blue lower layers, therefore the probable
height above water is about one-seventh of the total
thickness of the berg.
Sir John Murray estimates the submerged part of the
Antarctic berg as seven-eighths of the whole mass ; but, for
the reason that the mass throughout must contain large
quantities of air, Captain Scott considers the proportion to
be 5 to 1.
202 WATER : ITS ORIGIN AND USE
Vice- Admiral Marakoff, commander of the Kussian ice-
breaker Yermak, when in the Arctic regions made experi-
ments with twenty-six samples of ice, and found that the
specific gravity of the floating portion of the ice varies
from 6'5 per cent, to 16'4 per cent., while the average of
the whole is 12 per cent. The strength of ice was also
tested, glacier ice requiring 180 Ibs. to break it, floe ice
only 63 Ibs. ; other ice averaged 110 Ibs.
Where the ice forming icebergs is clear, compact, and
solid, it has a bluish-green or deep blue tint.
" The deep blue colour is due to the fact that the air has
been expelled by the constant melting and regelation
which takes place throughout the whole mass as it moves
over land."
" A cannon ball fired into the azure blue ice does not
penetrate, but large masses of ice fall away. When fired
into the upper areolar white layers of the table berg, it
penetrates without producing any visible effect."
Fragments of the latter were subjected to pressure and
impact, and could easily be deformed ; fragments of the
former behaved quite differently.
" Waves dash against the bergs, cutting caves and
caverns of the most heavenly blue. These cavities con-
tain fresh water, from the melting of the ice."
" As the bergs drift, they tilt and turn ; the submerged
prongs and spits are thrown high into the air, produc-
ing pinnacled bergs higher than the original table bergs."
Admiral Marakoff, when in the Arctic region, took the
temperature of the centre of a 14-foot ice-floe broken by
the Yermak and found it to be 28'2 F., or only 0-5 F.
below freezing point of sea- water. " I am not sure," he
says, " whether it shows that such thick blocks do not lose
entirely during the summer their excess of cold received in
winter."
ICEBERGS 203
His various experiments for melting point of ice from
different depths of the floe proved it to be very near the
freezing point of fresh water.
Sea ice was subjected to the influence of a current of
salt water at 29'8 F., and the ice melted in that temperature
very easily. " Tt is rather remarkable," he states, " that
ice melts in water the temperature of which is more than
2 below its melting temperature."
The specific gravity of liquefied ice was then tested,
proving it to contain very little salt indeed.
Surface ice gives the purest result ; but the bottom of the
floe gives a little more salt, salinity varying from O'Ol to
0*69, the latter from the spongy part of the floe.
The reader will probably ask what is the size of the
largest iceberg which has ever been seen.
Floating mountains of ice of all shapes and sizes up to
20 or 30 miles in length and about 12 miles in breadth
have been reported pretty often, while at least one berg
has been met with which towered no less than 1500
feet out of the water that is to say, the total height of
that block of ice was about 5000 feet ! But 30 miles is
not the record for length. On 17th January 1893 the
Loch Torridon fell in with a gigantic island of ice which
measured in one direction the almost incredible length of
50 miles ; and when she had sailed to the end of this side
of the berg, no end to the ice in the other direction was
visible, even from aloft.
In Baffin Bay Sir John Ross saw icebergs aground,
standing 1500 feet out of the water.
Reliable authorities have seen icebergs aground in 500
feet of water, standing 250 feet out of the same ; giving
the not unusual height of 750 feet for the greater icebergs.
An iceberg seen by Ross and Barry was 2 miles long
by 153 feet high, and supposing it was a cone reared on an
204 WATER: ITS ORIGIN AND tTSE
elliptical base, there would have been 150,000,000 tons of
ice above water ; the entire mass would equal 1,500,000,000
tons.
The largest iceberg seen by Captain Scott in the
Antarctic was apparently aground off King Edward Island,
5 or 6 miles long, and it seemed to run back an equal
distance. Many high ones were seen, one 240 feet.
The glaciers (Jakobshavn, Humboldt, etc.) of the Green-
land ice-field supply most of the Atlantic icebergs, and the
Antarctic ice-sheet those of the Southern Ocean.
Greenland has been called the mother of icebergs ; the
immense mass covers an area of 512,000 square miles ; the
whole of the interior is capped by an enormous glacier,
always moving towards the coast, breaking off in icebergs
which rise from 60 to 300 feet out of the sea.
Eecent observations of one of the principal discharging
glaciers of Greenland prove it to be 920 feet thick, 18,000
feet wide, having a summer advance rate of 47 feet
a day.
So enormous are some of the Arctic icebergs, and
the amount of heat required for their liquefaction is so
great, that they sometimes travel 2000 miles before
disappearing.
The means by which they travel such a distance is the
Polar Stream, which carries them southward from the
Arctic zone towards the Equator.
Referring to the icy monsters, Longfellow writes :
" Southward, for ever southward,
They drift through dark and day,
And like a dream in the Gulf Stream
Sinking, vanish all away."
The climatic effect of an iceberg is sometimes very
marked, frequently the lowering of the temperature warns
the mariner of its presence before it becomes visible.
ICE-FLOES 205
Notwithstanding frequent reference by many writers
to this lowering of the temperature in the vicinity of ice-
bergs, careful research and frequent experiment appear to
have exploded the idea that their presence is always in-
dicated in this manner, for Captain Magill tells us, in the
Geographical Journal, 1901, that if a ship is to the leeward
of an ice-field of vast extent, at a distance of a mile or two,
the temperature of the sea surface, and the air especially,
may be colder, but in the case of bergs no perceptible
difference will be noticed until too late to avoid a col-
lision. He states that he passed forty-five in four or five
hours, distant 1 to 7 miles, with no change of temperature ;
he also took the temperature of sea and air every ten
minutes from first sight to within one-quarter mile of a
large berg, and found no change whatever.
lee-Floes
Ice when formed on the surface of the sea is called field
ice ; when broken and piled up by wind and waves it forms
floe ice or solid masses of ice many miles in area. Unlike
the ice of icebergs, it is porous, incompact, and imperfectly
transparent.
When open sea freezes the first thin covering is called
" bay ice." Floe ice is a sheet of ice the limits of which
are visible ; ice-field a sheet of ice of such extent that
its limits cannot be seen.
Paek-Iee
This consists of fragments of an ice-field or floe forced
together by wind or currents.
The greatest thickness attainable by sea ice in Polar
seas is 7 feet. Old ice will become thicker in the second
year and attain 10 feet. Where floes 80 to 100 feet thick
206 WATER : ITS ORIGIN AND USE
are found, they reach this thickness only by the accumu-
lation of snow on the ice year after year.
Captain M'Clintock's ship Fox was frozen into an
ice-pack from August 1867 till the following April, and
during these 242 days the ship was carried southwards
1385 miles.
Many similar experiences are recorded, and many fine
vessels have been crushed by pack ice and their crews
have had to subsist for months on those floating islands of
ice until rescued by some passing vessel.
The following anecdote, from a most interesting little
book on ice by W. A. Brend, is an example of the hard-
ships referred to.
" In 1871 the Polaris, an American vessel exploring to
the north-west of Greenland, became frozen into the ice-
pack (lat. 79) near the entrance to Smith's Sound. On
the 15th October a storm arose and the pressure of the
ice threatened to crush the ship. Provisions were placed
upon the ice and nineteen persons retreated there for safety.
" During the night a channel opened between the floe
and the ship and the two parties drifted apart.
" Among the little party who thus commenced a drift
destined to last seven months were two Eskimos with their
wives and children, including a baby only four weeks old.
" Snow-huts were built on the ice-raft, and a fire was
sometimes made by using seal blubber as fuel.
" Great pieces of the floe broke off from time to time,
consequently diminishing the size, the portion of the ice
bearing the encampment fortunately remaining intact. "
The trials of this party, the weary months of anxiety
with the awful fear that after all they might be hurled
into eternity in a moment, the difficulties and want of
food, the awful exposure to cold, etc., need but a little
careful thought to realise. However, on 30th April they
SEA ICE 207
were rescued by the steamer Tigress, in latitude 53*35 N.
They had been 197 days on the ice, and had travelled
in this manner 1700 miles ; and, in spite of hardship and
privation, not a single life had been lost.
Similar experiences, with less happy endings, are unfor-
tunately well known ; it is little wonder that descriptions
of these Polar expeditions have such a fascinating attrac-
tion for all readers.
Sea Ice
Nansen has given us, as the outcome of his investi-
gations in the Polar regions, particulars of thickness
attained by the ice of the Polar seas by means of direct
freezing. The greatest thickness found without being
piled up was 13 feet 10 inches:
" As soon as ice is formed it grows very rapidly, but as
the thickness increases the growth becomes slower and
slower, as the loss of heat by radiation during the long
winter night has then more difficulty in penetrating down
to the underside of the ice. The ice which was formed
in October and November of the first autumn (1893) had
in April 1894 attained a thickness of 7| feet, but it con-
tinued to increase steadily during the summer. On 9th
June it had reached a thickness of 8 feet 3 inches, notwith-
standing there was already a severe thaw on the surface
caused by the rays of the sun. On 20th June the thick-
ness was still the same; the thaw on the surface was
considerable, and there were large fresh-water pools in
every direction. The rest of June the ice continued
about the same, until on 10th July it suddenly received a
new layer underneath, so that it measured a thickness of
9 feet, despite the decrease by thawing of an inch or two
a day on the surface.
208 WATER : ITS ORIGIN AND USE
" This formation of new ice on the underside was owing
to the layer of fresh water which, by reason of the surface
thaw on the ice, now floated above the cold salt water,
the temperature of which was considerably below the
freezing point of fresh water, and which cooled the latter
off so effectually that at the line between the fresh water
and the salt water, at a depth of about 8 feet, a layer of
fresh-water ice was formed.
" This lasted through the summer, but then the united
thickness of the old plus the new layer began to decrease
slowly until in September the thickness was about 6| feet.
The growth began again in October. On 10th November
the thickness had become 6 feet 7 inches; on llth
December, 7 feet, and continued to grow slowly through
the winter ; on 6th February the thickness was 8 feet
4 inches. During the spring the ice went on growing ;
on llth May 1895 it had become 9 feet 10 inches, and it
was the same on 30th May.
" It will thus be seen that the ice does not attain any
very considerable thickness by direct freezing, and this ice
had made the journey from the north of the New
Siberian Islands to the sea north of Franz Josef Land,
that is to say, across no inconsiderable part of the Polar
basin."
Icicles
Icicles vary in length from the tiny crystal spears we
see hanging from every ledge, sill, or window, to those 30
feet in length, found hanging over the sides of a crevasse,
where they usually form on the southern edges.
We will now try to find out how they are formed.
The rays of the sun melt the ice, but do not warm the air,
and the ice is melted though the air may be many degrees
below freezing ; as the water runs from the sunshine into
ICE FORMED IN CAVES 209
the shadow, it congeals and forms the nucleus of an icicle ;
this process continued builds up those beautiful spears of
transparent ice :
" Winter giveth the fields and the trees, so old
Their beards of icicles and snow."
LONGFELLOW (from Dante's Purgatoria).
Ice which accumulates under pressure (as in the case of
glaciers) differs from ordinary ice, which has a white
appearance, due to innumerable air bubbles in the mass.
In glaciers crystalline ice is formed ; the enormous pressure
squeezes out the minute air bubbles and leaves the ice
transparent and clear. I have seen the time by an
ordinary watch distinctly through a block of this ice
about 2 feet square, and a newspaper can be read easily
through the same.
Ice formed in Caves
Ice-caves so termed are seen where the formation of
subterranean ice occurs in caves. They are to be found
in various parts of Europe, Asia, and America, notably in
the Jura, Switzerland, the Italian Alps, the Eastern Alps,
in Tyrol, Russia, one in Iceland, one on the Peak of
Teneriffe, several in Siberia, one in Japan, and many other
places too numerous to mention.
This formation of ice in caves is supposed by one
writer (Mr E. S. Balch) to be "due to the cold air of
winter, which re-forms anew each year the ice which has
been destroyed by heat the preceding summer."
Another authority accounts for this interesting pheno-
menon of the forming of ice in caves by the theory that,
because of their depth below the surface of the earth, their
height above the sea-level, or their exposure to suitable
winds, or two or more of these conditions in combination,
14
210 WATER : ITS ORIGIN AND USE
they are unaffected by ordinary climatic changes, so that
the mean annual temperature is sufficiently low to ensure
the permanency of the ice.
An interesting reference is made to ice-caves in the Geo-
graphical Journal, 1902, by Mr H. H. Kimball, who states
that there are freezing caverns recorded in 300 places in
the entire world, sixty-five of these being in the United
States. In one of the Port Henry Mines, N. Y., which
contains ice all the year round, a temperature of 38 F.
has been recorded.
If water oozes into a cavern and then evaporates, the air
temperature of the cave is lowered, and ice forms.
In Iceland there is a cave of considerable dimensions
called Surtghellir, containing the most gorgeous ice stalag-
mites of all sizes and shapes, from the densest white to a
pale transparent blue. Here, as in the stalactite caves, the
icicles from above join the ice stalagmites from below,
forming glittering colonnades and screens, etc., in endless
variety. (The temperature of the cave is 33 F.)
The ice supply of the island of Teneriffe is obtained from
such a cave, which is 100 feet long, 30 feet broad, 10 to 15
feet high, situated on the Peak 10,000 feet above the sea-
level.
Extremes of Temperature (Arctic)
In the Arctic regions 73 to 84 F. below zero have
been recorded, but the coldest temperatures are not at the
Poles, for the circulation of the water tends to bring the
heat from the Equator.
The lowest temperature recorded by Captain Sverdrup
(of the Nansen expedition), taken north of Franz Josef
Land, was -62 F. ; the highest, -f 37 F.
Peary in these severe climes in 1898 experienced a
EXTREMES OF TEMPERATURE 211
temperature of 65 F. or 97 degrees of frost, the mean
temperature being stated as 53'18 F.
A few Antarctic temperatures will tend to make us
give some little thought to the hardships experienced by
explorers in the South Polar regions.
The Belgica records the minimum temperature for the
month of September as being 45'4 F. This was in 71
south latitude.
Captain Scott, at Cape Armitage on 16th May 1903,
recorded 677, or nearly 100 of frost.
The coldest regions are N.E. Siberia and N.E. America.
In Verkhoiansk in January the mean temperature is 55
F. below zero, and only reaches 5 above zero all through
the year.
It is stated that here 81 below zero has been recorded,
and that the soil is frozen to a depth of 400 feet.
In Siberia, at Irkutsk (50 to 52 N. lat.), mercury
freezes as early as November.
Labrador is described as the " most uninviting region
on the face of the earth, whose coast is blasted by frost
and beaten by waves : language fails to describe the awful
desolation of the Labrador peninsula."
Sir Archibald Geikie says : " England, clothed in peren-
nial verdure, and Scotland, where grass grows for eleven
months of the year, are in the same latitude as the frozen
and horrible coast of Labrador, the difference being almost
entirely due to the Gulf Stream."
The winter temperature of the Polar Sea is higher than
that of Siberia, proving that the sea tends to equalise the
temperature even in these rarely visited northern ex-
tremities, for in the former 62 F. has been recorded by
Nansen as the minimum, whereas at Verkhoiansk, in
Siberia, the minimum temperature is 90 F.
The capability of the human body to withstand extremes
212 WATER : ITS ORIGIN AND USE
of temperature differs according to temperament and
constitution. Some would rather suffer heat than intense
cold; some find the 78 F. below zero of Siberia quite
bearable, even pleasant on a calm day ; whereas, with a
temperature 60 higher, if the air be damp and wind high,
death might result.
Many feel a damp, foggy November day in London more
severely than the first- named temperature.
The men hewing ice on the Norwegian lakes may be
seen working in their shirt-sleeves. When arriving in
England with the blocks, they are muffled up, wearing
great-coats ; proving that it is not so much a matter of
degrees of cold as dryness and stillness of the atmosphere.
The same argument applies to heat : a moist heat of, say,
80 to 90 F. is simply overpowering, whereas a dry heat
of over 100 F. will not cause such inconvenience.
The general impression is that great cold is more easily
borne than great heat.
CHAPTER IX
GLACIERS
" The glassy ocean of the mountain ice."
BYRON.
INTERESTING as the forms of ice already mentioned may
have been, it is the glacier that will impress us most.
These rivers of ice move slowly ; yet, as Hartwig says,
" it might be supposed that the waters which congeal on
the sides of the mountains covered with perennial snow,
or fill Alpine valleys in the form of glaciers, were
eternally fixed on earth but there also we are deceived
by delusive appearances of immobility. Every year the
glacier slowly but restlessly makes a step forward into the
valley, and while its lower end dissolves, new supplies of
snow constantly feed it from above."
Let us see what we can learn of these ice masses, which,
formed by the congelation and compression of the moun-
tain snow, creep so stealthily down the mountain slopes
until they either evaporate or melt into rivers, or force
themselves into the lakes or seas.
They are, of course, common in the Polar regions, but
are not confined to these latitudes.
In the Himalayas we find rivers, up to 60 miles in
length, of ice coming from an altitude of 29,000 feet.
Mount Kenya and Mount Kilimanjaro in Africa, on the
Equator, send forth their rivers of ice, as also do the
mountains in South America.
213
214 WATER : ITS ORIGIN AND USE
Many glaciers terminate only after having thrust them-
selves down the valleys into the fields, orchards, and forests,
where their ends are being continually melted by the
sun's rays.
Formation of Glaciers
We have seen that above the snow-line more snow falls
than the summer sun can melt ; and it would go on
accumulating indefinitely, were it not carried away
regularly by means of glaciers.
That which is melted by the sun sinks down into the
mass, helping to consolidate it. Thus the deeper layers
become firm and compact, though there is a considerable
amount of air in them.
The mass, being on the sloping side of a mountain,
gradually acquires a gliding movement. The pressure
from above, and the narrowing sides of the valley, com-
press it still further, and this imperfectly consolidated
mass, partly ice and partly snow, is then known as neve
or firn. The air-bubbles imprisoned within its layers
cause it to be less transparent than ice formed from still
water. Eventually, however, by the continued and ever-
increasing pressure with which it meets in its tortuous
passage through narrow defiles, the air becomes expelled,
and the final product consists of clear, blue, compact
glacier ice.
The dazzling whiteness of the surface of a glacier is due,
says J. Y. Buchanan, F.R.S., " to the disintegration of the
compact blue glacier ice into its constituent grains under
the influence of the radiation of the sun.
" If a block of compact glacier ice be obtained from, say,
the extreme end of a glacier ice grotto, from such a dis-
tance as to be beyond the reach of direct daylight, when
brought out and exposed, in 20 to 30 minutes it will fall
RATE OF TRAVEL 215
into a heap of irregularly shaped pieces of ice, each of
which is a grain and a single crystalline individual."
In this compact and perfect form the glacier moves
much in the same manner as a river, though far more
slowly ; indeed, it may be described as a river of ice, carry-
ing away the unmelted snow from mountains.
"The entire mass of snow and glacier," says Ruskin,
"pass gradually and by infinite modes of transition one
into the other," and he goes on to describe it as " one great
accumulation of ice-cream formed on the top and flowing
to the bottom."
Rate of Travel
" The first great fact," says Ruskin, " to be recognised
concerning them is that they are fluid bodies, sluggishly
fluid indeed, but definitely and completely so ; they do
not scramble down, nor tumble down, nor crawl down, nor
slip down, but flow down, like what they are made of,
water."
Tyndall also refers to them as " issuing from the hollows
of the eternal hills, and stretching like frozen serpents
through the sinuous valleys."
The speed at which a glacier travels is governed by
the angle of its slope and the amount of pressure from
above.
In summer the melting of the ice causes more water to
flow through the cracks and crevasses, carrying fine matter
with it, and this, with the more yielding nature of the ice
under the influence of the warmth, no doubt accounts for
the increased movement in summer as compared with
winter. In winter the supply of water reaching the bed is
cut off by the frost, and the ice, at least to a certain depth,
is frozen hard and has greater resistance.
It has also been found that the upper portions or layers
216 WATER : ITS ORIGIN AND USE
of a glacier move more quickly than the lower ones, and
the middle travels faster than the sides, which are retarded
by friction against the rocky walls. This may be proved
by driving a row of stakes into the ice in a straight
line across a glacier thus .... It will be found in
time that those in the centre have outstripped those at
each end of the row, and the stakes, instead of being in a
straight line, form a bow, thus . . across the glacier.
The result is that the medial moraine is compressed
longitudinally and is spread out laterally, which explains
the widening of the medial moraine. The movement is
like that of a viscous body, the centre flowing past the
sides, the top flowing over the bottom ; and glacier motion
through a curved valley corresponds with fluid motion.
The space at our disposal will only admit of reference to
a few of the most prominent glaciers and their rate of
travel, but the information given will apply to all glaciers
generally.
The Mer de Glace of Chamonix travels at the rate of
209 feet per annum at the source of the Arveiron ; at the
base of the Montanvert, 822 feet. The motion is twice
as fast in spring and summer as in winter. The mean
daily rate of the Mer de Glace is, in summer and autumn,
from 20 to 27 inches in the centre, and from 13 to 19
inches near the sides.
If a spike were driven into the centre of this glacier on
a summer day, it would be found to move at the rate of
1 inch in an hour.
It is estimated that the mass of ice of the Aar Glacier
requires 133 years to descend from summit to extremity
a distance of 10 miles.
The average velocity of the Alpine glaciers varies from
50 to 120 yards a year, or from 6 to 15 inches a day.
BATE OF TRAVEL 217
Professor Hugi built a hut upon the glacier of the
Unteraar in 1827. In 1830 (3 years) it had moved down
330 feet ; in 1836 (9 years) it was 2354 feet lower; and
in 1841 (14 years) the hut was found to have travelled
4712 feet from its first position.
The ice-tongues of Erebus Bay travel at the rate of 3
feet per month.
The Ferrar Glacier (Greenland type) travels in winter
5 feet per month, in summer 12 feet ; the Ross ice-sheet
(Antarctic) 100 feet, Spitzbergen (Garwood) 800 feet,
Karajak Glacier (Drygalski) 1500 feet per month.
In Greenland the ice-field from the interior is constantly
relieving itself in the shape of icebergs, some over 400
feet high.
The breadth of this glacier (Jacobshavn) is 14,760 feet ;
the dip is less than half a degree ; the centre part in
summer travels at the rate of 65 1 feet a day ; midway
between the sides and the middle, 49 feet ; and close to the
sides, only half a foot a day.
The lowest ends of glaciers are found to advance and
retreat according to the greater or smaller fall of snow on
the mountains, and the increase or decrease of temperature
in the regions into which they advance. The speed of
travel of the sides of the glacier is regulated by the curves
in the valley down which it is passing. At one point the
western side is moving the faster, at another point the
eastern side has a quicker motion, the pace being retarded
always on the inside of the curve.
Ruskin says : " Never an instant motionless never for
an instant without internal change, through all the
gigantic mass, of the relations to each other of every
crystal grain. That one which you break now from its
wave-edge, and which melts in your hand, has had no rest
day nor night since it faltered down from heaven when
218 WATER : ITS ORIGIN AND USE
you were a babe at the breast ; and the white cloud that
scarcely veils yonder summit seven-coloured in the
morning sunshine has strewed it with pearly hoar-frost,
which will be on this spot trodden by the feet of others,
in the day when you also will be trodden under feet of
men in your grave."
Extent of Glaciers
Notwithstanding the fact that all the glaciers have
their periods of advance and retreat, yet they are
considerably smaller than they were in ages gone by ;
this diminution is no doubt steadily going on now, but
glaciers of enormous extent still exist.
There are in Switzerland 471 glaciers, which cover a
total area of 800 square miles. Austria claims 462. Of
those in Switzerland 138 are large, being over 4| miles long.
The longest glacier in the Alps is the Gross Aletsch
(Bernese Oberland), 15 miles long, which has a basin of
49'8 square miles and a maximum breadth of 1968 yards ;
the next in length is the Unteraar Glacier, 10'4 miles
long. The Gorner and Viescher are each 9 '4 miles. The
lowest point to which they descend is 3225 feet ; this was
attained by the Lower Grindelwald Glacier in 1818.
We can form but a vague idea of the amount of ice
contained in these, which may be termed small glaciers,
but it has been calculated that the ice of the Gorner
Glacier would be enough to build three Londons. The
depth of the Alpine glaciers varies, and some writers have
estimated that in certain instances it is as much as 1600
feet.
In the Himalayas we have enormous glaciers which have
their origin in the towering peaks some 29,000 feet high ;
these rivers of ice extend in some cases 60 miles in length,
filling the valleys.
EXTENT OF GLACIERS 219
Chimborazo, only 2 from the Equator, sends forth
glaciers in all directions.
The glaciers of North America are of enormous extent;
here there is a belt of snow-capped mountains over 3000
miles long and 80 to 100 miles broad, in which glaciers
are of common occurrence.
The glaciers of New Zealand are also very interesting,
the chief being Tasman, 13,664 acres in area, 18 miles long,
1 miles average width, and nearly 2 miles greatest
width.
The New Zealand glaciers, like those of nearly all
countries, including the Arctic, are receding. The Clyde
Glacier, between 1866 and 1871, had receded 305 feet ;
and in 1880, when again visited, the shrinkage was very
evident.
The giants of this branch of nature's work are found in
the Polar regions.
The area of Greenland is about 700,000 square miles. Of
this area 600,000 square miles are buried beneath a glacier
of the continental type, the central part of this covering
being 8000 feet above sea-level. Professor Russell says
the central ice-sheet is many hundreds of feet thick, and
possibly 7000 or 8000. This ice is drained off in ice-
streams, some from 10 to 30 miles broad ; one, the
Humboldt Glacier, which flows westward into Baffin's
Bay, has a breadth of 45 miles where it enters the sea,
and gives birth to enormous icebergs.
Nearly all the Greenland glaciers are tongues from the
internal ice-cap, and terminate in vertical faces from 100
to 1000 feet high. The glacier movement at the ice-borders
varies from a foot per day to a foot per week.
In Franz Josef Land the Great Dove Glacier is 60
miles wide.
One of the broadest glaciers known is in North-East
220 WATER: ITS ORIGIN AND USE
Land, Spitzbergen (area 6200 square miles). The island
appears like a broad plateau covered by an ice-sheet 2000
to 3000 feet in thickness, slowly moving towards the
east. This immense sheet of ice discharges into the sea
by a huge ice-wall, unbroken by any promontories for 150
miles, and is known as Dickson's Glacier.
We see therefore that, in comparison with the enormous
glaciers in Greenland, and in the South Polar regions,
those formed in the Alps are mere streaks of ice.
Tributary Glaciers
Tributary glaciers meet and form a large one just as
small streams combine to form a large river, but here we
are dealing with ice instead of water. Professor Tyndall
says they are " tributary valleys, which pour their frozen
streams into the great trunk valley." Let us take one
instance only, for it is interesting to see how they become
compressed in the process of formation.
Tributary Glacier du G^ant .. 1134 yards wide.
de Lechand . 825
Talefre 638
2597
" At Trelaporte these three rivers of ice are forced through
a gorge 893 yards wide, or one-third of their previous
width, at a rate of 20 inches a day " (Tyndall).
One of the above tributaries, Glacier de Lechand, has
to suffer a still greater compression, for from a width of
825 yards it has to pass a granite vice at Trelaporte 88
yards wide, or about one-tenth of its original dimensions.
In this process the ice is changed in form only, not in
volume ; it has to adjust itself by altering in shape from
|, in exactly the same manner as water would
PLASTICITY AND REGELATION 221
accommodate itself to the same circumstances. This
alteration in form of the solid mass, from the horizontal
to the perpendicular, is accounted for by the viscous
qualities of the ice particles of which it is composed, and
the mighty force necessary to effect the change is provided
by the weight of the vast superincumbent mass of the ice
above.
Plasticity and Regelation
Plasticity, as the word implies, is the quality of " taking
form," and regelation, or re-freezing, is a name given to
the phenomenon presented by two pieces of melting ice,
brought into contact either in the air or in water, when
congelation and cohesion (more simply, joining and re-
freezing) take place ; this will occur if the atmosphere, or
the water in which the operation is being conducted, has
a temperature of so much as 100 F. It is stated that this
was first observed by Faraday.
Ruskin sarcastically remarks : " Let good Professor
Faraday have all the credit of showing us that, and the
human race in general the discredit of not having known
so much as that, about the substance they have skated
upon, dropped through, and eaten any quantity of tons of
these two or three thousand years ; that the wonderful
phenomena of congelation, regelation, degelation, and
gelation pure, without preposition, takes place whenever a
schoolboy makes a snowball ; and that miraculously rapid
changes in the structure and temperature of the particles
accompany the experiment of producing a star with it on
an old gentleman's back."
In order to find the temperature of a mass of glacier
ice, an interesting experiment was carried out on the
Hintereisferner (Tyrol). Here a boring was made into the
glacier situated 8530 feet above sea-level, through 500
222 WATER: ITS ORIGIN AND USE
feet of ice, the precaution being taken to wash out the
borings with water to prevent their freezing again. It was
found that the temperature of ice, throughout the mass, is
at the melting point, and that the surface moves more
quickly than the bottom (Geographical Journal).
Water, when subjected to great pressure, freezes at a
lower temperature ; so when ice is subjected to pressure it
melts, and when the pressure is removed the water again
solidifies.
This may be demonstrated by placing a block of ice on
two supports and hanging an iron wire, weighted at each
end, over it. The weighted wire pressing on the ice melts
it and cuts its way through the block ; the water freezes
again behind the wire, and fills up the space, leaving no
trace of its passage beyond a few bubbles of air.
If ice is strained in any way, as by the travel of a glacier,
it relieves itself in the above manner and a similar regela-
tion follows.
This proves that ice, though hard and brittle, possesses
the property of plasticity to a remarkable degree, and
enables glaciers to adapt themselves to their tortuous
paths.
This, which is called the viscous theory of glaciers, has
been explained satisfactorily by Professor James Thompson
by the phenomenon of the melting and re-freezing of ice.
This gives, I hope, a complete explanation of the plas-
ticity of glaciers, and shows that, though imperceptible,
melting and re-freezing are continually going on, which will
account for the yielding at the points of stress. It will
also enable us to understand better how the glacier slides
not only on the bottom and sides of the rocky valley, but
slides more readily on itself, the centre moving faster than
the sides and bottom ; also how it winds its way, hard
and brittle though it be, squeezing through narrow valleys,
Mrs Aubrey Le Blond.
NEAR TOP OK MONTE ROSA TRIBUTARY GLACIERS AND MORAINES JOINING.
Mrs Aubrey Le Blond.
THE MONTE ROSA GROUP FROM WELLENKUPPE-GLACIER PASSING
THROUGH A NARROW GORGE.
[To face p. 222.
PLASTICITY AND REGELATION 223
turning at sharp angles, passing over rough, uneven surfaces,
always on its downward path.
The opportunity to watch this movement is given only
to a few ; we can, however, all do as Ruskin did. At
Hotel du Mont Blanc was a pot of Chamonix honey, stiff
and white ; he says : " It gave him command of the best
possible material for examination of glacial action on a
small scale."
" Pouring a little of its candied contents upon my plate,
by various tilting of which I could obtain any rate of
motion I wished to observe in the viscous stream, and
encumbering the sides and centre of the said stream with
magnificent moraines composed of crumbs of toast, I was
able, looking alternately to table and window, to compare
the visible motion of the mellifluous glacier and its trans-
ported toast, with the less traceable, but equally constant,
motion of the glacier of Bionnassay and its transported
granite."
Another simple experiment of his was to put a little
hot water on a lump of sugar in a teaspoon, and obtain an
artificial thaw of the mass, which he describes as " sub-
siding, by a series of, in miniature, magnificent and appal-
ling catastrophes, into a miniature glacier, which you can
pour over the edge of your spoon on to your saucer."
It is worthy of notice how great men find the simple
articles of food upon their tables useful in helping to un-
ravel some of the greatest scientific knots. The late Lord
Kelvin took a raw and a hard-boiled egg, suspended them,
and set them spinning, and observed that one revolved
longer than the other; from this he drew certain conclu-
sions as to whether the centre of our globe has a solid or
a liquid core. And Professor Tyndall, in studying crystal-
lisation, found that " in the formation of a bit of common
sugar-candy, there are agencies at play the contemplation
224 WATER : ITS ORIGIN AND USE
of which, as mere objects of thought, are sufficient to make
the wisest philosopher bow down in wonder, and confess
himself a child."
Moraines
Moraines are formed on the surface of glaciers by the
fragments of rock which fall from the side of the rocks
and are carried down by the ice.
When two or more tributary glaciers meet, a medial
moraine is formed, each moraine keeping its individuality
distinct, though the mass of ice has by compression formed
one solid mass.
Irrespective of the distance they have to travel, and the
narrow defiles through which they have to pass, these
separate moraines maintain their distinct positions, and
are eventually deposited at the lower end of the glacier ;
there they are called terminal moraines.
The ancient glaciers, no doubt, moved more rapidly than
their diminutive descendants of the present day, but at
the existing rate some of the large erratics would have
taken from 2000 to 4000 years on their journey.
It is from the terminal moraines, which we find left
behind in the valleys, that the original or maximum length
of any glacier can be calculated and its diminution noted.
These boulders are known as erratic blocks.
Erratic Blocks
" As a huge stone is sometimes seen to lie
Couched on the bald top of an eminence ;
Wonder to all who do the same espy,
By what means it had hither come, and whence."
J. C. SHAIRP.
Erratic blocks are huge boulders strewn on the tops
of promontories, carried by long-vanished glaciers, and
deposited in their present positions.
SAND-CONES AND GLACIER-TABLES 225
/
These blocks of stone receive their name (erratic) from
having wandered so many miles from their original homes ;
for instance, the Pierre-a-Bot, near Neuchatel, at a height
of 2200 feet, is 62 feet long, 48 feet wide, and 40 feet high,
and came from the Mont Blanc Range.
An erratic block of 24,000 cubic feet can be seen at
Mattmark Lake. It was left there forty-four years ago by
the Schwartzberg Glacier, which has now receded half a
mile from where it deposited its huge burden.
To come nearer home, at Wolverhampton there is a
wonderful concentration of thousands of granite blocks,
covering an area of 15 miles long and 4 miles broad.
These were, no doubt, deposited ages ago by glaciers.
Referring to these interesting wanderers, Tyndall states :
" On the solid waves of that Amazon of ice, the perched
boulders, the spoils of distant hills, quarried from summits
far away, and floated to lower levels like timber logs
upon the Rhone."
We find also, as the result of the work of glaciers,
roches moutondes, i.e. sheep-rocks, or stones scratched and
smoothed, rounded and polished; and deeply grooved
striated rocks, and many other indications which prove the
previous occupation of valleys by these rivers of ice in
past ages.
Sand-Cones and Glacier-Tables
Another interesting and curious result of the sun's rays
melting the surface of the glacier ice is seen when sand-
cones are formed. One of these is shown in the accompany-
ing picture, to the left of the erratic block that is in the
first stage of forming a glacier-table, being raised on its
icy pedestal only a little above the surface of the glacier.
The manner in which these cones are formed is worth
a passing notice. They have the appearance of consisting
15
226 WATER : ITS ORIGIN AND USE
of sand alone, but they are really solid ice, with merely
a covering of sand.
If dirt or sand be deposited by a mountain stream on
the surface of the ice, according to the thickness of the
sand, so will the sun's rays in proportion be prevented from
melting the ice ; therefore, where the sand lies thickest,
the melting will be least, and this point will form the apex
of the cone, being left higher and higher as the general
melting and lowering of the surface of the ice continues.
Under certain conditions they form groups and miniature
mountain ranges; and if the action referred to be suffi-
ciently prolonged, they will attain a height of 20 feet.
It is this protective action that also causes the moraine-
ridge, which has the appearance of having been raised by
pressure, but is really caused by the general lowering of
the surface of the ice around, leaving the ridge higher,
through having been protected from the direct rays of the
sun by the debris forming the moraine.
Small isolated stones, pebbles, or spots of dirt, however,
sink into the surface of the ice, by the action of the sun ;
the ice has then a honeycombed appearance.
Large isolated slabs of rock are frequently seen on a
glacier, standing on a pedestal or column of ice; these
columns are formed by the action of the sun and rain on
the ice surrounding them, for it is apparent that the sun's
rays cannot reach the ice underneath the rock, nor can the
rain wash it away.
The remainder of the surrounding ice gradually melts,
leaving the table of stone higher and higher in the air.
From the height of this pillar, the amount of ice that
has disappeared, since the stone first occupied that position,
can at once be seen ; eventually, however, the pillar
becomes so tall, and, by the action of the air, so thin,
that it gives way under the weight of the stone, which
CREVASSES 227
falls on to the glacier, only to repeat the process again
and again, until it is finally deposited at the end of the
glacier.
As will be seen in the illustration, the stones do not lie
horizonally upon the pillar of ice; it is found that the
degree and direction of the slope varies with the latitude,
owing to the position of the sun at noon, which melts the
ice on one side of the table, the other side being in shadow,
thus causing the stone to dip towards the sun.
It is in the heap of debris which forms the terminal
moraine that we find the polished and striated or scratched
stones, which tell us of their journey under the ice, where
the enormous weight above pressed them against the
surface and sides of the rocky valleys beneath the glacier.
" Although executed ages ago, they are as fresh and
unmistakable as if they had been executed last year."
Crevasses
A crevasse is a huge crack or opening formed on a
glacier, the result of the ice being severely strained.
Before leaving glaciers, we must spare a space for a
short description of a crevasse with its walls of clear
blue ice, which Tyndall mentions as being "filled with
ccerulean light, which deepened into inky gloom as the
vision descended into it, the edges of which were overhung
with fretted cornices from which depended long, clear
icicles, like spears of crystal."
There are three kinds of crevasses, each due to a
different action, viz. the transverse crevasse, the marginal
crevasse, and the longitudinal crevasse.
When glaciers are subject to tension, the ice breaks and
a report is heard like the firing of a gun. After a search
of some time a crack is seen, not sufficiently wide to insert
228 WATER : ITS ORIGIN AND USE
the blade of a knife; however, it widens out, owing to
the fact that the centre of the glacier is moving faster
than the sides, as we have already seen. When some
change in the channel occurs, altering or reversing the
stresses and strains, the old crevasses close up, and, under
the pressure, the sides freeze together again ; the glacier
thus preserves its continuity, a new crevasse forming at
the point of stress, and the process is repeated continually
during the passage of the glacier.
This can easily be proved. For, as already mentioned,
two pieces of ice placed together in water, above freezing
point, will freeze at the point of contact. Place several
pieces together in a line: they will all freeze together,
and can be moved as one piece, notwithstanding that each
separate piece is thawing.
Sometimes the crack will widen into one of those awful
gaping chasms (some being 500 to 700 feet deep) which
have claimed so many lives. A well-known instance is
the melancholy accident that occurred when Dr Hamel's
guides perished in a crevasse on the Grand Plateau (Mont
Blanc) on 20th August 1820. The bodies of these three
poor fellows were found in 1861, or forty-one years after they
were swallowed by this awful crevasse. Tyndall, describ-
ing his first ascent of Mont Blanc in 1857, predicted
the finding of these bodies, which really occurred about
four years after the following statement : " They are still
entombed in the ice, and some future explorer may per-
haps see them disgorged lower down, fresh and undecayed."
They were found, I believe, in perfect preservation, at the
end of the Glacier des Bossons, having moved some 4 miles
in forty-one years, or 500 feet a year.
To-day a crevasse still exists at this same spot, scarcely
distinguishable from the one that existed in 1820.
On 23rd August 1905 the remains of a tourist were
CREVASSES 229
discovered on the upper Grindelwald Glaciers, below the
ice-fall. It is supposed to be the body of a German
student from Sax-Weimar, who fell into a crevasse higher
up the glacier fifteen years before.
Mrs Aubrey le Blond, in True Tales of Mountain
Adventure, tells us how " a travelling seller of hats, cross-
ing the Tschingel Glacier on his way from the Bernese
Oberland to Valais, had fallen into a crevasse. Eventu-
ally his body and his stock of merchandise were found at
the end of the glacier. Near the Grimsel the remains of
a child were discovered in the ice. An old man remem-
bered that many years before a little boy had disappeared
in that locality, and must doubtless have been lost in a
crevasse."
The same writer has kindly given me permission to
quote extracts from the account of the Mont Blanc
catastrophe given in her book :
" In the year 1866, Henry Arkwright, a young man of
twenty-nine, aide-de-camp to the Lord-Lieutenant of
Ireland, was travelling in Switzerland with his mother and
two sisters. One of his sisters went with him as far as
the hut at the Grands Mulcts, and they were accompanied
by the guide Michael Simond, and the porters Joseph and
FranQois Tournier. Another party proposed also to go up.
It consisted of two persons only, Sylvain Couttet and an
employee of the Hotel Royal named Nicolas Winhart,
whom Sylvain had promised to conduct to the top when
he had time and opportunity. It was the 12th October
when they left Chamonix, and all went well across the
crevassed Glacier des Bossons, and they duly reached their
night quarters.
" While the climbers were absent next day, Miss Fanny
Arkwright employed herself in writing and finishing a
sketch for her brother.
230 WATER: ITS ORIGIN AND USE
" Meanwhile the two parties, having set out at an early
hour, advanced quickly up the snow-slopes. Sylvain
Couttet has left a remarkable description of the events
which followed, and portions of this I now translate from
his own words as they appeared in the Alpine Journal :
' We had been walking for about ten minutes near some
very threatening seracs, when a crack was heard above us
a little to the right. Without reasoning, I instinctively
cried, " Walk quickly ! " and I rushed forwards, while some-
one behind me exclaimed, " Not in that direction ! "
'I heard nothing more; the wind of the avalanche
caught me and carried me away in its furious descent.
" Lie down ! " I called, and at the same moment I desper-
ately drove my stick into the harder snow beneath, and
crouched down on hands and knees, my head bent, and
turned towards the hurricane. I felt the blocks of ice
passing over my back, particles of snow were swept against
my face, and I was deafened by a terrible cracking sound
like thunder.
'It was only after eight or ten minutes that the air
began to clear, and then, always clinging to my axe, I
perceived Winhart 6 feet below me, with the point of his
stick firmly planted in the ice. The rope by which we
were tied to each other was intact. I saw nothing beyond
Winhart except the remains of the cloud of snow and a
chaos of ice-blocks spread over an area of about 600 feet.
' I called out at the top of my voice no answer. I
became like a madman. I burst out crying, I began to call
out again. Always the same silence the silence of death.
' I pulled out my axe, I untied the rope which joined
us, and both of us, with what energy remained to us, with
our brains on fire and our hearts oppressed with grief,
commenced to explore in every direction the enormous
mountain of shattered ice-blocks which lay below us.
Mrs Aubrey Le Blond.
ICE-FALL, PERS GLACIER
(Formed by glacier passing over steep rocks.)
Mrs Aubrey Le Blond.
AN ERRATIC IN THE FORM OF A GLACIER TABLE, WITH SAND-CONE.
[To face p. 230.
CREVASSES 231
Finally, about 150 feet farther down, I saw a knapsack
then a man. It was Fra^ois Tournier, his face terribly
mutilated, and his skull smashed in by a piece of ice.
The cord had broken between Tournier and the man next
to him. We continued our search in the neighbourhood
of his body, but after two hours' work could find nothing
more. It was vain to make further efforts ! Nothing was
visible amongst the masses of de'bris, as big as houses, and
we had no tools except my axe and Winhart's stick. We
drew the body of poor Tournier after us as far as the Grand
Plateau, and with what strength remained to us we
descended as fast as we could towards the hut at the
Grands Mulets, where a terrible ordeal awaited me the
announcement of the catastrophe to Miss Arkwright.
' The poor child was sitting quietly occupied with her
sketching.
' " Well, Sylvain ! " she cried on seeing me, " all has
gone well ? "
' " Not altogether, Mademoiselle," I replied, not knowing
how to begin.
' Mademoiselle looked at me, noticed my bent head and
my eyes full of tears : she rose, came towards me " What
is the matter ? Tell me all ! "
' I could only answer, " Have courage, Mademoiselle."
' She understood me. The brave young girl knelt down
and prayed for a few moments, and then got up, pale, calm,
dry-eyed. " Now you can tell me everything, " she said,
" I am ready." '
"Thirty-one years had passed when, in 1897, Colonel
Arkwright, a brother of Henry Arkwright, received the
following telegram from the Mayor of Chamonix : ' Bestes
Henry Arkwright, peri Mont Blanc 1866, retrouvds.'"
During these thirty-one years the body of Henry Ark-
wright had descended 9000 feet in the ice, and now the
232 WATER: ITS ORIGIN AND USE
glacier had once more given up its victim, whose remains
were rendered back to his family at the foot of the glacier.
Many articles belonging to the lost one came to light by
degrees. A pocket-handkerchief was intact, and on it, as
well as on his shirt-front, Henry Arkwright's name, and
that of his regiment, written in marking-ink, were legible.
Though the shirt was torn to pieces, yet two of the studs
and the collar-stud were still in the button-holes and un-
injured. The gold pencil-case opened and shut as smoothly
as it had ever done, and on the watch-chain there was not
a scratch. A pair of gloves were tied together with a boot-
lace which his sister remembered taking from her own boot
so that he might have a spare one, and coins, a used car-
tridge, and various other odds and ends, were all recovered
from the ice.
The remains of the guides had been found and brought
down soon after the accident, but that of Henry Arkwright
had been buried too deeply to be discovered.
In 1906 a letter appeared in the Times from Lady Florence
Dixie saying that, according to a telegram from Geneva,
it was expected that the body of Lord Francis Douglas,
who lost his life forty years ago, during the first ascent of
the Matterhorn, would be delivered up by the slowly
moving glacier during the summer of that year.
It may be interesting to recall a few facts concerning
this first ascent of the well-known peak, renowned for its
steep, gaunt, granite summit towering to an altitude of
nearly 15,000 feet.
On 13th July 1865, Edward Whymper, Lord Francis
Douglas, the Rev. Charles Hudson, Mr Hadlow, and three
guides started off on what was to be one of the greatest
successes in mountaineering as well as one of the most
thrilling tragedies of the Alps.
After much laborious climbing, attended by the usual
Mrs Aubrey Le Blond.
MONT BLANC.
(The black line shows the probable course followed during nearly half a century by
Captain Arkwright's body in the ice.)
Mrs Aubrey Le Blond.
THE OVERHANGING CORNICEJlOF SNOW A FREQUENT SOURCE OF ACCIDENTS.
[To face p. 232.
MOULINS 233
dangerous experiences, the following day saw the hitherto
unconquerable task accomplished, Whymper and the guide
Croz reaching the summit first.
Having spent an hour enjoying a view never before seen
by human eyes, the return journey was commenced, all
being roped together, as is the usual custom.
Mr Hadlow unfortunately slipped, and fell upon his
guide Croz, knocking him off his feet ; both fell over the
precipice, pulling Hudson and Lord Francis Douglas with
them, when the rope broke, thus saving the lives of the
remainder of the party, who saw their companions dashed
to pieces 4000 feet below.
Three bodies were eventually recovered, but that of Lord
Francis Douglas has never yet been seen ; having fallen into
one of the innumerable crevasses, it is no doubt preserved,
frozen solid, in the glacier, which will some day yield him
up again to those dear friends who may be spared to
receive his body.
A ladder was lost in a fissure on the Mer de Glace (Mont
Blanc) in 1788, and was discovered in fragments in 1832,
forty-four years afterwards, having travelled at the rate of
130 yards each year.
Moulins
" The glacier to-day filled the air with low murmurs, which the
sound of the distant moulins raised to a kind of roar." TYNDALL.
Moulins are formed on glaciers in the summer, when
little rills and streams of water rush down the cracks in
the ice, forming deep shafts. These move forward with
the glacier, and new ones are continually being formed,
approximately in the same place, and so a succession of
moulins is formed. One on the Finster Aar Glacier had
a depth of 760 feet.
234 WATER: ITS ORIGIN AND USE
The water finds its way to the base or bed of the glacier,
and carries with it any fine particles of matter which
have been ground down by the action of the glacier on its
rocky bed, issuing from the terminal end of the glacier
as a muddy stream. For it is found that the layer of ice
in contact with the bottom and sides of the rocky valley,
by pressure of the enormous weight above, is usually in a
state of thaw or melting, and the water from the surface
of the glacier mingles with that of the bed. The Rhine,
Po, Ganges, and many other rivers owe their origin to
glacier streams.
It is this action that wears and grinds the rocks away.
The Rhone, for instance, which has its source in the
Rhone Glacier, carries a load of debris or matter into the
Lake of Geneva, where it is deposited, and the Rhone quits
the lake clear and blue. In the course of time this action
of glaciers will fill up the lakes.
Here again we see the wonders of the work of water
continually altering the configuration of the earth.
The water that gains access to the rocky bed of a glacier,
either through a moulin or a crevasse, frequently comes
into contact with large stones ; the combined action of ice
and water causes them to revolve ; this whirling in time
shapes and smooths the stones, at the same time wearing
in the rocky bed large pot-holes or "giants' cauldrons" as
they are termed in Scandinavia, where they are found of
considerable size.
In the glacier garden of Lucerne, which formed at one
time the bed of a glacier, there are a considerable number
of these interesting holes, with the stones in situ one pot-
hole or cavity measuring, it is said, 28 feet in width and
33 feet in depth.
Similar cavities are formed in the beds of swift streams,
where a large stone gets into a whirl of water or an eddy ;
Mrs Aubrey Le Itlund.
AN ACTIVE MOULIN OR GLACIER MILL.
[To face p. 234.
LAKES FORMED BY GLACIERS 235
they are also frequently formed at the base of a waterfall.
These are sometimes called " Devil's punch- bowls."
There is an old saying, " Continual dropping wears
away a stone " ; large quantities of water, falling from a
height, certainly excavate and polish enormous cavities.
lee- Barriers
When a glacier moves past the end of a tributary valley,
it sometimes dams back the stream, and the water thus
accumulated forms a lake, which continually increases in
extent until the barrier gives way under the pressure of
the water.
A lake of this description was formed in the valley of
the Dranse, Switzerland. Here an ice-barrier, half a mile
long, 400 feet high, 600 feet wide, stretched across the
valley, impounding 5,000,000,000 gallons of water.
To avoid a serious catastrophe, a tunnel was driven
through the ice and much of the water was drawn off ; but
before the lake was empty, the barrier gave way, causing
an immense amount of damage.
Other barriers of ice are of a semi-permanent kind, and
remain as long as the glacier is in existence. The beautiful
Marjelen See, on the Great Aletsch Glacier, with its float-
ing icebergs of snowy whiteness, is an instance of this.
When one of these reservoirs burst at Gietroz in 1818,
1,110,000,000 gallons of water were suddenly set free.
Crete Seche in 1894 and 1898 discharged 220,000,000
gallons, and in 1878 the Marjelen See evacuated in nine
hours 1,709,400,000 gallons.
Similar instances are more or less common to all
countries where glaciers of any magnitude exist ; some-
times the reservoir is formed on or in the glacier itself.
In most instances, however, they eventually burst with
236 WATER: ITS ORIGIN AND USE
most serious results, generally causing a flood, which
sweeps down the valley, carrying all before it.
Lakes formed by Glaciers
Several reliable authorities are of opinion that many
rock-basins, in which beautiful lakes are formed, were
scooped out by the grinding action of an ancient glacier.
The lakes of Killarney and many other well-known lakes
were doubtless hollowed out by this means.
" When glaciers teemed from the shoulders of Snowdon,"
says Tyndall, " and when the Eeeks of Magillicuddy sent
down giant navigators to delve out space for the Killarney
Lakes, and to saw through the mountains the Gap of
Dunlow."
All these now lovely spots were once held in the chilling
grip of ice, and it is supposed by some that these severe
conditions were passed long before the world was inhabited.
The pressure a glacier exerts on its bed is enormous. In
a glacier 600 feet deep, and allowing (according to Professor
Tyndall) 12'20 metres (or about 40 feet) of ice to an atmo-
sphere, we find that on every square yard of its bed a
glacier presses with a weight of about 300,000 Ibs.
Advance and Retreat of Glaciers
The terminal ends of some glaciers may remain station-
ary for many years, and then advance or recede.
Lord Avebury tells us that " during the Middle Ages the
Swiss glaciers appeared to have been increasing in size, and
to have reached a maximum about the year 1820 ; after
that they retreated till about 1840. They then again ad-
vanced until about 1860, since which time they have again
greatly diminished ; though some are now commencing the
Mrs Aubrey Le Blond.
A SHATTER OF BOULDERS, ARCTIC NORWAY.
(Illustrating how fragments of the peaks, loosened by the frosty air, poured in granite
avalanches down the mountains.)
Mrs Aiibrey Le Blond.
GLACIER LAKE, WITH POLISHED AND STRIATED ROCKS, ARCTIC NORWAY.
[To face p. 236.
THE GLACIAL PERIOD 237
advance again. Those of Northern Europe appear to be
also increasing."
In 1858 Tyndall visited the Gorner Glacier, of which he
states : " As is well known, the end of this 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. 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 had once passed over them."
Between the years 1845-1883 the end of the Vernaght
Glacier receded 2000 yards. This glacier has advanced
and retreated ten times since the beginning of the
seventeenth century.
That these oscillations occur at irregular periods is
beyond doubt ; and it is an accepted fact that, however
they may advance and retreat, the final result is a con-
tinuous retreat.
In many of the Swiss valleys the pressure of the ice must
have been very great. The Rhone Glacier at one time not
only occupied the basin of the Lake of Geneva (170 miles
below its present limit), but rose on the Jura to a height
of 3000 feet. This lake is 1100 feet deep, so that the
thickness of the ice must have been 4100 feet.
It is also agreed that the great ice-cap of the Antarctic
is but a remnant of its former self.
The Glacial Period
" It is a world disinterred by the sun from a sepulchre of ice."
TYNDALL.
We cannot leave this interesting subject without some
short reference to the Glacial Period or Ice Age, during
which both the old and new world, north of latitude 50
40, were covered with ice and glaciers, probably as thick
238 WATER: ITS ORIGIN AND USE
as that now found in Greenland. The mountains of
Scotland and Wales were covered with ice ; similar
conditions existed and were more or less general over
Northern Europe and North America. Where, as Tyndall
states, "the valleys were gorged by the frozen material
incessantly poured into them."
" A scene of unspeakable desolation it must have been,
when Europe was thus encased in frozen armour, and
when even the showers of her western isles fell solid from
the skies."
The Glacial Period has left us many traces of its exist-
ence. The vanished glaciers scratched and polished the
surfaces of the rocks, and by studying these their thickness
and the direction in which they moved can be calculated
approximately ; and no doubt can exist as to the circum-
stances under which they were formed, and of their
enormous extent. The vast sheet of ice buried North-west
Scotland 3000 feet; the hill-tops of the Cheviots, 2300
feet high, are distinctly glaciated ; this sheet of ice thinned
away to the south and east.
The great Scandinavian glacier occupied the North Sea
from Flamboro' Head to the mouth of the Thames. Erratic
blocks from Norway travelled on this ice-sheet and were
deposited at Cromer.
Coming nearer home, similar traces can be seen through
Borrowdale in Cumberland, the valleys near Beddgelert in
Wales, and many other places.
The British Isles at this period were almost wholly
covered by an immense glacier, as thick as that at present
to be seen in Greenland, on the recession of which England
and Ireland were found to be joined to the Continent.
"We see," says another authority, "the conditions
as existing in North Greenland extended to Middlesex,
Wales, and south-west of Ireland, vast fields of ice passing
THE GLACIAL PERIOD 239
over the Scottish Highlands, covering in the plains of
Perthshire to a depth of at least 2000 feet. The North Sea
was chilled with ice, and England and the north-west of
France were united."
In this period of the greatest cold 700,000 square miles of
Northern Europe was buried under a vast sheet of ice, which,
over Scandinavia, was said to lie about 6000 feet thick.
Another authority states that in Norway at this period
the ice must have been 7000 feet thick. " The high table-
land of Scandinavia," says W. A. Brend in his excellent
book on ice, " became a great centre of dispersal, from
which the ice radiated in every direction, north into the
Arctic, west into the Atlantic, south and east the glacier
pushed across Denmark and the Baltic, and invaded
Northern Europe."
Distinct traces of the mighty glaciers of the past are
also to be seen in the valley of Hasli, Switzerland ; here
the marks and polishing of the ancient glaciers can be
seen 2000 feet above the present valley beds.
"All around," writes Tyndall, "are evidences of the
existence and might of the glaciers which once held
possession of the place. The rocks are carved, fluted,
polished, and scored; here and there angular pieces of
quartz, held fast by the ice, inserted their edges into the
rocks and scratched them like diamonds."
In the Bernese Oberland the valleys were filled to the
brim with ice. Water, in the form of ice, played at this
period such an important part in both the old and new
world's history, that we must give some consideration in
our story to the probable cause of its action.
The climatic conditions of this period were probably
caused by some eccentricity in the movement of the earth
in its orbit ; which may occur again, bringing about a
repetition of the same conditions.
240 WATER : ITS ORIGIN AND USE
According to Mr Croll, cold periods recur regularly
every 10,000 or 1 5,000 years. The last great glacial period
occurred about 240,000 years ago, and endured with slight
alterations of climate for about 160,000 years.
Some writers suggest that there may be a recurrence
of these conditions in 21,000 years; others are of opinion
that, if it be due to astronomical reasons, it probably began
200,000 years ago, and that existing conditions only com-
menced to return 50,000 years ago : thus, as imperceptibly
as it began, the Ice Age came to an end.
At this period the mammoth and other animals migrated
to these shores, and in all probability man accompanied
them, and this was no doubt the first occupation of these
islands.
We know that among the remains of the first human
settlers those of the elephant, hippopotamus, rhinoceros,
horse, bison, deer, bear, etc., and all the smaller animals,
have also been discovered.
" Grand indeed was the fauna of the British Islands in
those early days. Tigers as large as the biggest Asiatic
species lurked in the ancient thickets ; elephants of nearly
twice the bulk of the largest now existing in Africa and
Ceylon, roamed in herds ; the lakes and rivers were tenanted
by hippopotami as bulky and with as great horns as those
of Africa."
Geology points out to us the successive changes the earth
has undergone, and in its various rocks we find embedded
and preserved remains of the various forms of life which
have passed away ; " the successive creation of which," says
Hugh Miller, " was to introduce man upon the surface of
our globe. Man is the end towards which all the animal
creation has tended from the first appearance of the first
Paleozoic fishes."
He also tells us of the tusks and grinders of 500
ONE OF THE MAMMOTH TUSKS FOUND IN THE DRV CHALK VALLEYS.
,SCTiON
B
3 EOT I ON -"T
SKETCH, SHOWING CURVE AND SECTIONS.
[To face p. 240.
THE GLACIAL PERIOD 241
mammoths dredged up by the oyster-dredgers on the
Norfolk coast from a tract of submerged drift.
The remains of several of these gigantic animals have
been found in the glacial drift in one of the dry chalk
valleys in Kent. The portion of the tusk shown in the
accompanying photograph was 9 feet long, and the writer
was unable to remove it, as it was too fragile. When the
tusk was cut through, each ring of ivory could be seen
distinctly ; they were perfectly white, and fell apart
separately ; the ivory, which in substance resembled very
soft chalk or hard soap, could be cut through easily with a
sharp knife.
Five of these enormous tusks were found, but could not
be removed, and about twenty large teeth were found.
Those in the brick earth near the tusks fell to pieces upon
exposure to the air ; those about 3 feet lower down, in a
mixture of rubble chalk and earth, were in splendid con-
dition ; several enormous bones, apparently of the legs,
were also found, in good preservation.
All these were more or less scattered, and pointed to
the fact that the animals did not" die there, but that these
remains had been deposited or carried there by the action
of water.
This goes a long way to prove that these dry valleys
were formed under severe conditions, similar to those that
must have existed in the Glacial Period.
A relic of this period was lately excavated in Russia
by M. Herz a male mammoth in complete preservation.
Portions of undigested food were found in the stomach and
between the teeth, so perfectly had the ice preserved it
for so many years. It was taken to St Petersburg in its
frozen state.
" The remains of the Elephas primogeniuA" says Hugh
Miller, " are so abundant in the frozen wastes of Siberia,
16
242 WATER: ITS ORIGIN AND USE
that what have been, not inappropriately, called ivory
quarries, have been wrought among their bones for more
than a hundred years."
Referring to these and similar discoveries of the remains
of prehistoric animals, Dr Buckland writes :
" "We have seen that the surface of the land, and the
waters of the sea, have, during long periods and at distant
intervals of time, preceding the creation of our species, been
peopled by many different races of vegetables and animals,
supplying the place of other racesthat had gone before them."
How these enormous creatures became extinct has
always been a subject of contention. "The old notion,"
says Darwin, " of all the inhabitants of the earth being
swept away by catastrophes at successive periods, is very
generally given up. On the contrary, we have every
reason to believe that species and groups of species
gradually disappear, one after another, first from one
spot, then from another, and finally from the world.
Certainly no fact in the long history of the world is so
startling as the wide and repeated exterminations of its
inhabitants."
Other proofs exist in these valleys of a considerable
amount of water having found its way to the sea by these
channels. In several the solid chalk is not reached until
about 50 feet of rubble chalk has been passed through,
which has the appearance of having been rolled and washed
by water, and re-deposited.
Here again, on one side of the valley, dry chalk banks
are found, with but little soil to cover them ; on the
opposite side of the valley, and at the junction of the two
valleys, rich earth has been deposited ; and brick earth is
found to a depth of over 20 feet.
This must have been deposited at about the termination
of glacial conditions.
THE GLACIAL PERIOD 243
The reader will probably ask, What has this to do with
our subject? Surely water in the form of ice at this
period did far more than we can comprehend in making
and forming this and other lands to be a fitting habitation
for man.
In the Glacial Period elements' that occupied different
districts were by its action mixed together as well as dis-
integrated, carried over, and deposited on the hard chalk,
rock, and other formations, covering them with rich soil
well adapted for the growth of vegetation.
Had it not been for the Glacial Period, many vast
districts now rich in the production of fruit and flowers
would have been almost barren wastes, and of little value
for agricultural purposes.
Here again the work of water in the Glacial Period
was to prepare the surface of the earth and provide a
source of agricultural wealth, so that posterity could sow
and plant, reap and gather into barns, the necessaries of
life, which, but for its influence, could never have been
produced.
CHAPTEK X
SPRINGS
" Then sing along the gushing rills,
And the full springs from frost set free,
That brightly leaping down the hills,
Are just set out to meet the sea."
BRYANT.
A SPRING is an outflow of water from the earth, or a
stream of water at the place of its source.
Having followed atmospheric water through the process
of evaporation and in the various forms in which it reaches
the earth, let us now trace its passage through the soil
and rocks, on its way back to the sea. It may fall on the
land, evaporate from its surface, be absorbed into the
tissues of animal life, or be built into the structures of
plants ; it may fulfil many mechanical duties, but the sea
is its ultimate destination, for these are but delays, trans-
formations, and changes ; eventually, by rivulet or stream,
it returns to the mighty reservoir, the ocean, from whence
it came.
" Thus," says Dr Buckland, " in the whole machinery
of springs and rivers, and the apparatus that is kept in
action for their duration, through the instrumentality of a
system of curiously constructed hills and valleys, receiving
their supply occasionally from the rains of heaven, and
treasuring it up in their everlasting storehouses, to be dis-
pensed perpetually, by thousands of never-failing fountains,
we see a provision not less striking than it is important."
244
SURFACE SPRINGS 245
From the surface of the ocean a continuous stream of
vapour is rising up into the atmosphere, to be re-
condensed and precipitated as rain, snow, sleet, etc. It is
estimated that ^ T of these precipitates returns directly to
the ocean (falling into the sea) ; the remaining ^ falls on
the land, collects, forms pools, lakes, rivers, or penetrates
into the earth, to appear again as springs, or to form our
supplies in underground reservoirs, into which we sink
deep wells.
Surface Springs
We have already seen how the rain percolates, forming
surface and deep-seated springs.
These springs of various types vary in strength from
time to time in proportion to the amount of rainfall, for it
is evident that as much water comes out of the earth in
the form of springs (visibly or invisibly) every year as
soaks into it ; for, like a sponge, when full it can hold no
more.
Dr H. K. Mill states that " one-third of the rain which
falls upon the surface of the earth, in a region like Great
Britain, for example, sinks into the ground, and the
greater part of it returns to the surface at a lower level
than it started from."
Dr John Murray calculates that 130 million million
tons of water, or about one-fortieth of the whole mass of
the atmosphere, are transferred from the sea surface to the
land, and find their way back again in streams and rivers
every year.
The manner in which these streams burst from the
sides of the rocks is as follows :
Where the outcrop of clay or other impervious deposit
has above it a porous rock, as Chalk or Sandstone, the
water passes from the surface through these strata, forming
246 WATER : ITS ORIGIN AND USE
subterranean reservoirs at various depths. On reaching
the clay its course is stopped, when the water accumulates,
and, by means of some natural channel, issues from the
base of the porous formation as a surface or crop spring,
so termed from the fact that it issues at the outcrop of the
underlying formation. (See Geological Section.)
Around these springs and the streams formed by them
are the ancient villages. These spots were no doubt
selected by our ancestors in consequence of the plentiful
supply of pure water.
Many springs of this description may be seen issuing
from the southern face of the North Downs, at the base
of the Chalk formation overlying the Gault clay, around
which luxurious vegetation thrives.
Deep-seated Springs
For an example of deep-seated springs, we cannot do
better than confine our attention still to the North Downs.
A part only of the water that falls on this formation issues
from its southern face as surface springs.
The slope or dip of this formation is in a northern direc-
tion. Before the mighty dome or arch of chalk, reaching
over the Weald and joining the South Downs, was removed
by denudation, the rainfall ran in this direction, forming
what are now the innumerable dry chalk valleys.
True, they are dry, no surface stream is to be seen.
Every valley possesses its watercourse, but here it is only
to be found at a considerable depth from the surface,
where not only is every crevice or cavern filled with
water, but every minute space ; the small interstices of all
permeable strata beneath the line of saturation are charged
with water, forming a plentiful source of water of great
purity, which, when not interfered with by man, secretly
discharges into the rivers and seas.
t?; /'
s ;f
lx ' ' ^ij&V.-p,A If
* it ' ' f - J 7"-l^ " /. v^v'*"*" "^ * 'Y-S
7/ ^ ->'- ; ^= - <: - . . - . v^.f - , ^:-2 *H-
: / / > "* ' * 7*" 1 " '.Sii*ii *. x <* its
. ^ ..' ?* ._*-'" / <- T*^* *"_ / . TT V^Vv ^
DEEP-SEATED SPRINGS 247
All over the earth large streams of water flow through
the natural cavities of the earth's crust unseen and
unknown, in a manner similar to that seen in the caves of
Adelsberg, the mammoth Cave of Kentucky, and innumer-
able other caves found in the limestone regions.
Many disappear and reappear on land, but many vanish
altogether, ultimately, no doubt, to well up from the
bottom of the sea.
Many suggestions as to the manner in which these dry
chalk valleys were formed have been put forward, but to
me the explanation given by Professor Phillips appears
the most probable ; he says : " The numerous undulations
upon the surface may be traced into connection as so
many ramifications of greater valleys, which themselves
unite, and pursue a considerable course without enclosing
even the smallest rill, or showing even the mark of a
watercourse. These dry valleys descend from their origin
in regular slopes and are clearly the work of water,
operating with great force, and for some time, but in the
present system of nature the watery agent has wholly
disappeared."
In the Geographical Journal (vol. xv. p. 215) Dr Mill also
states that their formation came about at the end of the
Glacial Period, when the whole mass of chalk was frozen
into a hard and impervious rock, in which the torrents
resulting from the melting of the higher snow cut out the
valleys.
If the reader will look carefully at the hill-shaded map
showing these dry chalk valleys, this will be most apparent.
The winding courses of these valleys can be seen dis-
tinctly, converging into the principal valley, like so many
tributary streams ; this principal valley itself leading
direct to the sea, it follows precisely the same winding
course that it would do if it were a river of water
248 WATER: ITS ORIGIN AND USE
instead of a dry valley. That these valleys were once
occupied by running streams of considerable force is
apparent ; and the large water-worn chalk boulders,
already referred to as having been redeposited by water in
these valleys 30 to 50 feet below the present surface, also
point to this conclusion.
Others attribute the cause to the fractures in the
formation by the upheaval of the soil, followed by ages of
excessive percolation, causing the destruction of the chalk
chiefly by the carbonic acid in the water dissolving it and
carrying it away.
In this formation it is generally found that water-
courses follow the valleys, also that percolation is quicker
in the valleys. This is due to the fact that in ancient
times, in severe weather, they carried a large amount of
water over their surface, and at the termination of the
frost absorbed an enormous amount of water during the
remaining seasons of the year.
Again, these dry chalk valleys have, by the above means,
had several hundreds of feet of their surface removed (by
denudation). The water therefore reaches the line of
saturation with less rock to impede its progress downward.
From actual experience I have found that percolation
is quicker in the valleys, and that the watercourses of the
different valleys are generally separate and distinct from
one another. This has been proved in the chalk valleys
between Chatham and Boxley, in Kent.
Here the well, marked "A" on the plan, is fed by a
powerful spring, which has for about fifty years supplied a
very large community with water.
More water being required, a well, " B," was sunk
in the adjoining valley to the westward, about mile
distant, where a very considerable amount of water was
found.
?
I
DEEP-SEATED SPRINGS 249
When wishing to connect the two wells " A, B " together
by means of adits from the bottom of the first well, the
water was found to come from separate sources.
For the purposes of driving this adit, the water in well A
was kept down on the bottom. During the work the water
in well B stood at a level 60 feet above A, and remained so
until the adit from A was within about 10 feet of well B.
Again a well was sunk in another valley J mile to the
south of well A, and the previous experience was repeated.
A very large watercourse was intercepted, which was
proved to be separate from both A and B.
We will now take the valley in which well A is sunk.
Here we find that all the wells throughout the valley,
which runs in a south-easterly direction, are influenced by
the pumping at A.
This influence has been felt for a considerable distance.
These separate valleys are therefore, as experience proves,
divided by masses of harder chalk, almost impervious.
Should a well be sunk in one of these harder masses,
the result would be disappointing.
- This was done (at D), and the yield of water was
practically nil, notwithstanding that the depth was below
the line of saturation, that adits were driven, and water
diviners predicted running streams.
I might also mention that two diviners were consulted.
Both predicted a supply, but gave different directions as
to the way in which the adits should be driven to intercept
the "flowing water," a term they frequently use. The
instructions of both were followed and both directions
tried, but both failed. This, I think, proves that "the
days of miracles are past," and that to predict the presence
of water successfully the hazel twig should be supplanted
by a geological knowledge of the district, coupled with
experience and common sense.
250 WATER: ITS ORIGIN AND USE
Another interesting experience in connection with wells
in the Chalk formation, bearing upon the same subject and
proving the density of these masses, is worth recording.
Several wells, indicated on the plan and section by
the letters E, F, G, H, I, exist close to each other and
alternately on either side of a little village street.
The depths of these wells are most remarkable, and
prove how, in some places, these blocks or bands of hard
and practically impermeable chalk will upset the most
careful calculations when searching for water. Curiously,
the deeper wells are not in use, owing to their great depth,
and yet the water never rises above the levels shown in
the section.
These dry chalk valleys are nevertheless a splendid
source of supply. They are bountifully provided with
deep-seated springs. They give us a pure, cool, refreshing
supply of water of a uniform temperature both summer
and winter.
This water, being naturally pure, requires no filtration
or other treatment, and under the modern methods of
pumping and distribution, does not see the light of day
from the time it leaves the underground natural reservoirs
in the chalk until it is drawn from the domestic tap.
How these wells are sunk and the water obtained will
be more fully described in Chapter XVIII.
Fault Springs
When a water-bearing stratum, bearing a hydrostatic
pressure (due to its " head "), is imprisoned between two
impermeable beds, and finds its way to the surface through
a fault in the upper impermeable strata, it is called a fault
spring.
Here the conditions are similar to an artesian well or
SUBMARINE SPRINGS 251
spring, the fault taking the place of the hole bored in the
formation.
In every formation there are faults, which vary in
importance according to the geological conditions, their
extent, and the effect produced; the smallest fault, in
certain cases, will cause a spring of water to issue in a
dry and barren land, bringing fertility ; other enormous
faults produce but little apparent results.
These great cracks are caused by upheaval on the one
side, or by the formation having been thrown down on the
other, in some instances the difference amounting to
thousands of feet.
Darwin, in his Origin of Species, mentions the Craven
Fault, which is 30 miles in length, the displacement
varying from 600 to 3000 feet ; also a downthrow of
2300 feet in Anglesey, and one of 12,000 feet in
Merionethshire ; yet on the surface there is nothing to
indicate these vast differences, so completely has subaerial
and littoral action, through the lapse of endless centuries,
smoothed down and obliterated all surface indications of
these mighty movements of our earth.
Darwin mentions this to impress on the mind of the
reader the vast duration of time, whereby agencies, " which
seem to work so slowly, have produced great results."
Submarine Springs
A " submarine " spring, as the name implies, is a fresh-
water spring bursting up from the bottom of the sea.
The manner in which these are formed will be seen by
reference to the geological section marked A, and described
as a submarine spring. Also by the larger sketch, which
shows it more distinctly.
These springs are pouring their contents into the seas
252 WATER : ITS ORIGIN AND USE
around our coasts. Some may be seen at low tide, but
many are never seen.
" Where the rainfall percolates," says Dr Fischer, " it
forms underground reservoirs for the supply of springs
and underground rivers : in some cases these are connected
by channels with the sea. Here the pressure of the salt
water holds up the water in the above channels to a
height above the sea-Jevel corresponding with the lower
specific gravity of fresh water.
When, however, the upper level of the fresh water is
raised, equilibrium is disturbed and fresh-water springs
rise up near the shore. Such are found in all parts of the
world.
Millions of gallons of water also escape from fissures in
the foreshore of St Margaret's, East Kent, and in Dover
Harbour fresh water rises up below the sea-line in great
volumes.
The amount of water passing into the sea around our
coasts in this manner is enormous.
Professor Dawkins states that in the course of a survey
of the estuary of the Humber for a projected tunnel, vast
volumes of clear water were noted rising like the head of a
column in the muddy tidal waters between Barton and
Hessle, locally known as the Hessle Whelps.
Innumerable underground caves, and rivers flowing
through them, have no visible communication with the
surface, and can never be discovered unless by chance,
as at the Strood Waterworks, Kent, when well-sinking
operations cut through the natural cavities. The sources
of similar supplies are the percolation of rainfall on the
mountains and hills in the limestone and other porous
rocks ; and, unlike the caverns caused by disappearing
rivers, are hidden from our sight.
These underground channels change their course, as
THE ORIGIN OF SPRINGS (after Prestwich).
The curved lines show the varying line of saturation.
g g s, the variable springs.
SECTION TO ILLUSTRATE INTERMITTENT SPRING.
DIAGRAM SHOWING HOW A FAULT MAY CAUSE A SUBMARINE
SPRING TO BE FORMED.
A A, rock impervious to water.
B B, permeable rocks.
C, fault by which water escapes under hydrostatic pressure.
[To face p. 252.
SUBMARINE SPRINGS 253
surface streams do, by altered geological conditions, disrup-
tion, etc. ; an instance of this can be seen in the Adlesberg
Grotto.
Hartwig tells us that in the Gulf of Spezia and in the
Port of Syracuse " large jets of fresh water mingle with
the brine."
Another author mentions this notable example, which
he describes as the Polla di Cadiinare, in the Gulf of Spezia.
It shoots up to a height of 60 feet from the sea bottom and
forms a small hillock on the surface ; the water that feeds
it falls as rain on the Apennines three miles distant.
Humboldt mentions a still more remarkable submarine
fountain on the southern coast of Cuba in the Gulf of
Xagua, a couple of sea miles from the shore, which
gushes through the salt water with such vehemence that
boats approaching the spot are obliged to use great caution.
Sailing vessels are said sometimes to visit these springs
in order to provide themselves, in the midst of the ocean,
with a supply of fresh water.
" And in the middle of the green salt sea
Keeps his blue waters fresh for many a mile."
TENNYSON.
In the West Indies, ^ mile off the coast of the Dutch
island of Saba, fresh water can be seen bubbling up in
small circles.
In a paper by H. Benest (Geographical Journal, 1899)
on this most interesting subject, we find : " Imagine such a
subterranean river as that of Bramabiau in the department
of the Gard, France, with its seven cascades, its tributaries
of Le Bonheur, De la Trouche, and La Riviere du Sud,
with its four miles of galleries, great halls, basins, tunnels,
fissures, avenues or swallow holes, and ramifications of
bewildering extent. Then the subterranean river of
Padirac, 2 miles long, at a depth below the Plateau du
254 WATER: ITS ORIGIN AND USE
Gausses de Gramat of 350 metres ; and only think that
such discoveries may yet be made as may probably outdo
these in extent, then it will not be wondered at that
submarine outbursts of pent-up waters occur below sea-
level."
"It is shown," says M. Benest in the same paper,
" that the hottest region of the earth is the south-west coast
of Persia, bordering on the Persian Gulf. The thermometer
during July and August never falls below 100 during the
night, while in the daytime it rises to 130 ; little or no
rain falls, and yet, in spite of this terrific heat, a compara-
tively numerous population contrive to live, slaking their
thirst from the copious springs of fresh water which burst
forth from the bottom of the sea."
Capillary Attraction
This is the name given to certain phenomena exhibited
by fluids, the scientific explanation of which is outside the
scope of this work; but briefly, it is molecular action
between liquids and solids, and plays a very prominent
part in nature ; it is by this means that the blood circulates
through the smallest blood-vessels in our body, even to the
very roots of our hair ; that the sap rises in plants ; that
moisture is absorbed by roots and leaves of trees ; that
water rises in the sponge, oil in the lamp-wick, etc. ; and
if we bear in mind these examples when we consider the
phenomenon of the height to which water rises in the
earth above its "natural" level, we shall be enabled in
some degree to grasp how it is that the line of satura-
tion varies in height in the various watersheds, causing
the water to stand higher than the theoretical line of
saturation.
Ill
q *"
s^i
55S5
S J
\ *
*,
.t,
Ifl
LINE OF SATURATION 255
Line of Saturation
The line of permanent saturation is that point in any
formation to which the water rises and whence it flows
out in the shape of surface and submarine springs. The
rainfall percolates to the line of saturation but does not
permanently raise it.
The line of saturation is usually considered as being
an imaginary straight line, drawn from the base of the
porous formation at the outcrop of the impervious stratum
to the sea-level.
This is hardly so, for the resistance of the rock and the
capillary attraction cause the water to rise to a higher
level in the formation, as shown in the accompanying
diagram, called the line of variable saturation.
These interesting phenomena, variable and intermittent
springs, are generally due to the temporary raising of
the line of variable saturation, by abnormal rainfall, or by
the melting of snow.
Intermittent Springs
A continuation of dry years, therefore, affects surface
springs, and when the line of saturation becomes reduced
to any considerable extent, they cease to flow. When it
returns to its normal level, they burst forth again. Where
this is of frequent occurrence, they are called intermittent
springs.
There is another kind of intermittent spring. This will
be more easily explained by the sketch in the accompany-
ing diagram. These springs discharge a large amount of
water for a time and then cease. The water percolates
and accumulates in the natural reservoir A, from which is
an outlet in the form of a syphon. The water rises in this
256 WATER : ITS ORIGIN AND USE
reservoir to the level of the top of syphon B. The
discharge then takes place, the whole of the water is
syphoned out of the reservoir down to level of C, and
the spring ceases to flow; when the reservoir is again
filled up the operation is repeated, and the contents of
the reservoir are again poured out.
Professor Prestwich, F.K.S., in writing of springs of this
description, states that " where the ridge of an anticlinal
curve in a water-bearing stratum is lower than the out-
crop of the bed, the water ascends the curve, which acts
as a syphon, there being no communication with the
surface, and drains off all the water between, and the
spring ceases to flow until recharged, which explains the
origin of the intermittent springs of Lavant, in Sussex ;
the Bourne, near Croydon ; and several at the foot of the
chalk downs at Folkestone, in Kent."
Intermittent springs are also formed in districts where
the rainfall is at times abnormal. The line of saturation is
then temporarily raised, and water flows out at a higher
level, ceasing as soon as the conditions again become
normal.
Variable springs are those which do not entirely cease
to flow, but yield a greater or less quantity of water
according as the climatic conditions are either wet or dry.
Effect of a Drought on Springs
Before leaving the subject of springs, let us note the
effect of a long-continued drought on deep-seated springs
in the Chalk formation.
A series of careful observations, extending from August
1894 to January 1902, showed that there was a deficient
rainfall, more fully given on the diagram on the opposite
page.
DIAGRAM SHOWING THE EFFECT OF A SUCCESSION OF DRY YEAKS (1895-1902) ON
THE DEEP-SEATED SPRINGS IN THE DRY CHALK VALLEYS OF THE NORTH
DOWNS, LUTON, CHATHAM.
(Plotted by the author from the Electrical
Recorder diagrams.)
1894
28-41
RECORD OF RAINFALL (1895-1902) IN INCHES.
1895
22-38
1896
2369
1897
21-88
1898
17-86
1899
21-56
1900
24-53
1901
17-58
1902
18-16
During this period there was a deficiency of one and a half year's rainfall, the average for
this district being 26 inches. The following year, 1903, was, however, a record year, 32 J inches
being recorded.
[To face p. 256.
INFLUENCE OF RAIN ON SPRINGS 257
The diagrams from which these curves were plotted
are recorded daily by an ingenious invention called the
electric water-level recorder.
These curves show the gradual diminution in the
strength of a large, deep-seated spring, in the chalk, as the
dry years followed with marked regularity.
The well is shown, and the adits at the bottom branch-
ing off in various directions.
The curves plotted on the section are only given from
9 feet from the well bottom, so as to avoid the adits ; and
only that portion of the curve is given (five hours' duration)
that was covered by the daily variations of the water for
the entire period under observation, and throughout the
period the daily amount of water pumped was practically
uniform or constant.
It will be seen that on cessation of pumping during
August 1897, in five hours the water rose in the well from
9 to 51 feet, or 42 feet rise, whereas in January 1902, in
the same number of hours, it only reached 29 feet, or a
rise of 20 feet.
No curves are given since January 1902, as from that
date there was an alteration of conditions, which would
cause them to be of no value for purposes of comparison.
These curves show the disastrous effect of a long-con-
tinued drought when the pumping at last exceeded the
amount of annual percolation of rainfall. This caused the
reduction in the rest-level, so far below the line of satura-
tion.
Influence of Rain on Springs
It will also be interesting to find out, as nearly as
possible, how soon after the end of a drought the deep-
seated springs begin to feel the benefit of the renewed
rainfall.
17
258 WATER : ITS ORIGIN AND USE
Some writers give three or four months as the time that
will probably elapse before the rainfall reaches the line
of variable saturation in the chalk hills. The following
observations were made with the view of finding some
reliable data as to what happens in the chalk valleys,
where the line of permanent saturation is about 169 feet
from the surface, and the variable line of saturation in
abnormally wet seasons 147 f feet from the surface (surface
level 160 feet above sea). [There had been removed, by
denudation, probably 200 feet of chalk from this valley, the
surrounding hills varying in height from 300 to 400 feet
above sea-level.]
A deep well was sunk in the chalk by the writer in
1902, after the eight years of deficient rainfall already
mentioned, the records of which are of sufficient import-
ance to be recorded in detail
The average rainfall for Chatham, Kent, is 26 inches.
From 1895 to 1902 there was a deficiency of 41 inches,
or an amount equal to about nineteen months' rainfall.
This well was finished late in 1902, when it contained
91 feet of water. This depth continued constant up to
the termination of the drought, and represented the
reduced line of saturation due to the drought, which
came to an end in May 1903. The following table
shows both the rainfall and the varying depth of water
in the wells, and demonstrates how quickly the rainfall
reaches the line of saturation.
inches. IQ feet<
1903
January j> w' ,.;.;, . 2'09 91
February v> v ., . 1-27 91
March " . . . . 1-88 91
April . If . ;> ' 1'82 91
May .... 2-40 91
INFILTRATION AND POLLUTION 259
Date.
inches. In feet
1903
June .... 5-88 92
July .... 4-70 93
August .... 2'91 94
September ... 1-66 96
October . . . 4*15 97
November . . . 2-42 100
December . .1-34 103J
32-52
1904 -
January . . 3'31 104
February . . . 2'84 109
March 1-4 112|
The improvement apparently commences from about one
month after the break-up of the drought. The well in
question was not influenced directly or indirectly by any
pumping operations, neither was any water abstracted
from it during the period tabulated.
These figures were taken by the writer personally, and
no trouble was spared to ensure accuracy.
For measuring the depth of water in this well, a special
instrument was designed by the writer which has since
proved to be most reliable.
Infiltration and Pollution
Before leaving the subject of springs, we must give a
passing notice to infiltration of sea or river water, etc.,
into pure-water springs.
The cause of infiltration is usually excessive pumping.
That is to say, that an amount of water in excess of the
v '
annual percolation has been drawn from the wells, the
level of the water being reduced until the natural order is
260 WATER : ITS ORIGIN AND USE
reversed. Instead of surplus water from the well passing
on to the sea, the sea or river water flows back into the
well and pollutes it.
This occurrence is not unusual, even in wells at a
considerable distance from the source of contamination,
for it is apparent that the channels by which the pure
surplus water from the well flows into the river or sea
will, if conditions be reversed, as readily conduct water in
the opposite direction.
It is frequently found that at high tide the sea- water
dams up the fresh water in the subterranean channels,
causing it to rise in wells and springs, so that more water
is obtained at high than at low tide. In some wells water
can only be obtained when the tide is high : the water is
pure and fresh. The tide here merely raises the level of
the spring water in the well by preventing its escape from
a lower outlet ; but if the distance from the sea or river be
considerable, the time occupied by the water in reaching
the well or boring produces the opposite result. For
instance, a boring at Fulham, 318 feet deep, yields less
water at flood-tide than during the ebb.
Darwin found that the natives of Keeling Island
obtained their pure water from " ebbing wells " or wells
sunk in the sand or porous coral rock, which is saturated
by sea-water. The rain which falls on the surface dis-
places the sea-water as it sinks into the rock, the fresh
water rising and falling with the tides. These ebbing
wells are common, he states, in the low islands of the
West Indies.
In some wells sunk in the sandy deserts of the southern
borders of Algeria fish have been found, proving that
water travels many leagues from where it has leaked into
the crevices and tunnels of the earth from lakes or rivers.
In the Argostoli peninsula, in the island of Cephalonia,
The Author.
A DEEP-SEATED SPRING IN THE DRY CHALK VALLEYS OF NORTH DOWNS.
This spring is bursting through the face of the rock into the artificial adit 240 feet below the
surface (100 feet below the line of saturation). It is yielding about 1,500,000 gallons per day.
[To face p. 260.
GEYSERS 261
2,000,000 cubic feet of sea-water disappear through the
fissures of the rock, and it is presumed that this reappears
in the brackish springs of the island.
Referring to the percolation of sea-water, Dr K. Natterer
concludes that, as a general rule, sea-water is percolating
through the capillary pores of the mud on the ocean
bottom, being sucked in by the underlying rock strata.
When sinking artesian wells, water of inferior quality
is often met with, and tubes are forced into the boring to
prevent it from contaminating the pure supply.
Under certain circumstances, water from a stratum
having a hydrostatic pressure will rise in the earth and
disappear in the porous formation at a higher level. Deep
borings have frequently been sunk and a larger source of
supply tapped, but the water has failed to rise to the
surface. This proves the necessity for water engineers
to study the geology of their district ; a boring of this
kind would apparently be yielding nothing, when a
plentiful supply might be obtained by inserting tubes in
the bore-hole to convey the water through the porous rock,
to the surface, without loss.
Geysers
" Into the sunshine,
Full of the light,
Leaping and flashing
From morn till night !
Into the moonlight,
Whiter than snow,
Waving so flower-like
When the winds blow !
Into the starlight,
Rushing in spray,
Happy at midnight,
Happy by day !"
J. R. LOWELL.
262 WATER : ITS ORIGIN AND USE
We will now pass on to the springs of a very different
kind, viz. " geysers." This word is derived from the Ice-
landic name of geysa, from gerso, to gush or rush forth.
Geysers are boiling fountains, which spout intermit-
tently. They are usually situated in volcanic districts.
The enormous power required to eject the mass of water
is supposed to be steam generated and accumulated in a
large cavern in the earth.
When the pressure sufficient to overcome the weight
of the water has accumulated, the water is ejected
periodically.
Referring to the geysers of Iceland. " Blasts of super-
heated steam," says Professor E. Suess, " entering the tube
laterally at great depths, are subjected to the pressure due
to the column of water in the tube, which raises the boiling
point, let us say, from 100 to 124 C. Successive hot
blasts eventually raise the temperature to 124 C. and the
explosion follows; the upper column of water is blown
into the air."
The " Bunsen " and other theories are put forward to
account for this enormous pressure.
In the south-west of Iceland, about 30 miles from the
crater of Hecla, there are over one hundred geysers within
a circuit of 2 miles. Eising through a bed of lava, they
throw their columns of boiling water into the air.
Few play for more than five or six minutes at a time,
and the periods of inactivity vary from about two hours
to thirty hours.
The principal one, which is called the Great Geyser, dis-
charges a column of boiling water from the summit of a
mound of siliceous deposit over 20 feet high.
The discharge is nearly always announced by rumbling
noises like distant firing of cannon, as a prelude to the
approaching activity.
GEYSERS 263
Of this geyser it is stated that it spouted eleven times
a day in 1770 ; in 1814 every six hours.
The height to which this column of water ascends has
also been variously stated as 360 feet in 1770 and 100 feet
in 1864 : the latter was an actual measurement.
Since this date a height of 200 feet has been recorded.
The water spouts higher and higher with each successive
pulsation until the maximum is reached.
The display occupies about 7| minutes, and the height
of the eight jets in which the water issues would average
about 45 feet.
The natural pipe or outlet through which the water is
ejected is 10 feet diameter, quite cylindrical, and no
irregularity was found to a depth of 68 feet ; but from 68
to 80 feet it is irregular. No measurements beyond this
depth are recorded.
One display, therefore, is equal to about 1,410,000 gallons,
or over 6000 tons of boiling water, which is hurled into
the air in 7 minutes.
Silica and soda are the chief constituents of this water ;
the specific gravity being 1*0008 (Faraday). The tempera-
ture of the water at the surface is 187. At a depth of
78 feet down the pipe it increases to 257 F.
The Earl of Dufferin visited this geyser in 1856.
" After watching over it for three days, he was at last
rewarded. He considered it a magnificent spectacle, the
display lasting seven or eight minutes. The height of
the column did not exceed 60 or 70 feet; he considered
100 feet as the probable maximum. Many trustworthy
records give 200 feet, but he considered 300 feet as
fabulous. "
If the heights recorded in 1770 and other years are
correct, it is evident that the powers of this mighty
fountain are waning ; we may then expect it to degenerate
264 WATER : ITS ORIGIN AND USE
eventually into a boiling spring only, and this is a reason-
able conclusion.
Boiling springs, many ages since, may have been
geysers; if so, there is no reason to suppose that this
fountain was not much more powerful 130 years ago than
it is to-day.
Another most interesting geyser is " The Old Faithful,"
in the Yellowstone Park in the United States. This
national reserve is 55 miles wide, 65 miles in length, and
comprises 2,288,000 acres.
It is entirely a region of thermal waters; scarcely a
foot of the 3575 square miles but has been honey-
combed by active, passive, or extinct fountains ; there are
now seventy-one geysers and some 3000 hot springs in this
district.
The eruptions of " Old Faithful " begin with a few
spurts lasting about four minutes ; they then become more
powerful, and jets rise with a roar in rapid succession to a
height of 130 feet, the steam ascending 500 feet. The
beauty of the display is often greatly increased by rain-
bows.
Geysers and hot springs are found also in New Zealand,
Arkansas, California, Nevada, British Columbia, Mexico,
Thibet in fact in nearly all parts of the globe.
The geysers of New Zealand deposit much common
salt and other mineral matter, which forms pools of
flinty rock of beautiful shape and colour, covering many
square miles with siliceous deposit, to which we shall refer
presently.
Water as a Solvent
Water is the most powerful and general solvent found
in nature, hence it is never found quite pure, for it will
hold in solution almost all bodies, and as a rule it holds in
THERMAL OR HOT SPRINGS 265
solution a greater quantity while hot than when cold : on
cooling, the surplus matter is precipitated in the form of
crystals, and if the remainder be evaporated, more crystals
will appear.
There is probably no terrestrial substance which, under
proper conditions, is not to some extent soluble in water.
All surface rocks contain water. No mineral substance
is strictly impervious to the passage of this liquid.
" Even in the rain which falls on the chalk hills and
passes into the deep-seated springs, about 1| ^ ons f
material per million gallons of water pumped is found,
and when this is abstracted additional storage is provided
for 110 gallons of water" (De Ranee).
Thermal OP Hot Springs
Thermal springs, as the name implies, are either hot,
warm, or tepid, which issue from the earth in a similar
manner to the ordinary surface springs, having a tempera-
ture far above that of the atmosphere. For instance, there
are the thermal waters of Carlsbad 165, Wiesbaden 158,
Baden-Baden 111 to 154, Bath 104 to 120, Aix-les-Bains
109 to 112, and Buxton 82.
Referring to " The Student's Lyell," it is stated that " the
comparatively small spring ' Bath ' has relieved the earth's
crust, in 2000 years, of as much heat as was dissipated in
the eruption forming Monte Nuovo during three days in
1538. Nor was the actual amount of matter brought from
the earth's interior, and deposited on its surface by the
Bath spring, less than that resulting from the outburst
that produced the Monte Nuovo ; but while in the latter
case the materials were piled up round the volcanic orifice
and remain to our view, in the former they were carried
into the Avon, from the Avon into the Severn, and by the
latter delivered to the ocean.
266 WATER : ITS ORIGIN AND USE
This is given as illustrating how much may be effected
by slow, continuous action, as contrasted with violent and
spasmodic activity."
It is an interesting fact that life is possible in these
waters : in the waters of Hamman-Meskoritin the little
beetle Hydrobius lives and thrives in a temperature of
130 F.
Thermal springs are not confined to volcanic districts.
The hot springs of Bath, for instance, are 900 miles from
the Icelandic volcano on one side, and 1100 from those of
Italy and Sicily on the other.
In many parts of the world hot springs issue from the
earth heavily charged with carbonate of lime, which cover
the country around with beds of calcareous tufa or
travertine.
The pink and white terraces of Kotomahana (New
Zealand) formed one of the most marvellous sights of the
world. These consisted of a series of basins formed by the
deposit of the siliceous matter in the water in the hot
springs, which fell in cascades from basin to basin, forming
a series of terraces with a flinty surface like polished
marble. These basins were fringed with stalactites and
filled with clear blue water of various temperatures.
The district covered by the hot lakes measures 120 miles
from north to south by 20 miles in width, the surface is hot
and crumbling, and it is an easy matter to get immersed
in boiling mud.
On 10th and llth June 1886, Mount Tarawera burst
into activity, and a series of volcanic explosions occurred.
Mountains were uprooted and hurled from the centre of a
range 2 miles long and to a depth of 1400 feet. With
these mountains disappeared the pink and white terraces
and springs of Rotomahana, and many of the natives in
a neighbouring village were overwhelmed.
THERMAL OR HOT SPRINGS 267
In the Grand Soufriere of Dominica there is a lake in an
active state of ebullition, 2400 feet above the sea. It is
600 feet wide, and no bottom was touched at 195 feet.
In Palestine there are many springs of hot water, which
issue forth on both sides of the Jordan Valley, the tempera-
ture of which ranges from 109 to 144 F.
Thermal springs, with an average temperature of 80 F.,
exist on each side of the Sea of Galilee. Hot baths south
of Tiberias include seven springs, the largest having a
temperature of 137 F.
In New Zealand, within a short distance of the terminal
face of the Fox Glacier, is a hot spring the temperature of
which is over 100 F. On the ice-bound top of Mount
Euapehu (in the North Island), 9100 feet high, there is a
boiling lake in the centre of the crater, into which the
surrounding ice melts.
Another remarkable instance is that of Chilian in the
province of the same name on the western flank of the
Sierra Nevada, 2050 feet above sea, where icy-cold and
boiling springs exist in close proximity to one another.
There are also the hot wells near Suez called " Eyoon
Moosa," or the " Fountain of Moses " ; also those called
" Hamman-Pharaoon," or the " Bath of Pharaoh," whose
waters resemble in their constituents those of the Dead
Sea.
At Hot Springs, a village in Arkansas, U.S.A., there
are sixty hot springs which together have a flow of
500,000 gallons per day, the temperature varying from 93
to 150 F. Many of the hot springs of Iceland have a
temperature of 208 F. and smell strongly of sulphuretted
hydrogen.
Earthquakes frequently influence mineral and thermal
springs. The springs of Cauquenes (Central Chili), after
the great earthquake of 1822, ceased to flow for nearly a
268 WATER : ITS ORIGIN AND USE
year ; the earthquake of 1835 also caused the tem-
perature of the water to fall suddenly from 118 to 92
F. (Darwin).
Climatic conditions have no influence on hot springs
they gush out even from under the snow in the
Himalayas.
Coming near home, we have within a short distance of
one another, at Buxton, both hot and cold springs, the
former at a temperature of 80, which supply water at the
rate of 60 gallons a minute.
Thermal and Mineral Waters
In referring to these waters, Hartwig says : " How truly
wonderful is the chain of processes which first raises
vapours from the deep and eventually causes them to gush
forth from the entrails of the earth, laden with blessings
and enriched with treasures more inestimable than those
the miners toil for."
The water in descending, percolating, and rising through
various mineral masses becomes impregnated with gaseous
saline or metallic admixtures which impart to them
particular properties. These waters are called mineral
waters, and are named according to the predominant
constituent.
There is apparently great difficulty in classifying these
waters, for nearly every spring contains some proportion
of the characteristic ingredient of another group.
One writer sarcastically remarks that "nature of her
bounty has furnished us with innumerable healing springs,
to help us to remedy the ills we have brought upon our-
selves by errors of diet and living." He speaks feelingly,
and as if from experience, and his rough classification of
these waters, with their principal element, is of interest.
THERMAL AND MINERAL WATERS 269
1. Thermal . Heat.
2. Muriated . Common salt.
3. Alkaline . Carbonate of sodium.
4. Sulphated . Sodium sulphite (Glauber's salt) or
magnesium sulphite (Epsom salts).
5. Chalybeate . Iron.
6. Arsenical . Arsenic.
7. Sulphur . Sulphuret of hydrogen, sodium, calcium,
potassium or magnesium.
8. Calcareous . Earthy substance.
Springs of this description, like all nature's gifts to man,
are more or less common in all countries.
We in England may be forced to travel to see many of
nature's wonders, but the spas of England, the remedy for
many ills, are fortunately near our doors, and of such
variety as to be unsurpassed by those abroad.
The very fact of their being near to hand, like other
things and scenes, seems to bring them into contempt,
the result being that our own mineral waters have
been, and still are, greatly neglected, people who can
afford to do so preferring to patronise those in other
countries.
In the Daily Telegraph on 5th June 1906 a correspondent
gave some interesting news of an accidental discovery of
mineral water in boring for water for the new public baths
in Camberwell.
The water was found to assume a rusty tinge on
exposure to the air, and to be rich in iron, comparable in
this respect to the water of Tunbridge Wells.
In 1678 Dulwich Wells were held in high repute, the
chalybeate waters being largely used medicinally. A
writer of that period describes them as being " a certain
cure for every ill to which humanity is heir."
Streatham is also stated to have possessed mineral
springs in the middle of the seventeenth century ; these
270 WATER: ITS ORIGIN AND USE
waters were supplied to many of the London hospitals as
late as the beginning of the nineteenth century.
Other famous springs existed in the environs of London,
including Hampstead, whose springs were in great request
in the seventeenth and eighteenth centuries (Well Walk
exists to-day), and at a period of their greatest popularity
were advertised and described as " inexhaustible fountains
of health." The same writer, however, tells us that when
George III. bestowed his patronage upon Harrogate and
Cheltenham, these waters declined sadly in popularity.
Harrogate is especially favoured, having, it is said,
eighty different wells which cannot be equalled for variety
and efficacy.
The muriated waters of Homburg and Wiesbaden are
also to be found at Llandrindod Wells and Woodhall Spa.
Sulphated waters, somewhat similar to those of Carls-
bad, Apenta, Hunyadi Janos, Friedrichshall, and Eubinat,
could also be obtained at Cheltenham and Leamington.
Chalybeate waters, more or less similar to Homburg
and Rippoldsan, can be found at Harrogate, Llandrindod,
Tunbridge Wells, and Buxton.
Indifferent waters are found at Wildbad, Baden, Gastein,
etc., also at Buxton,
Earthy waters such as Borinio, Dax, etc., are found at
Bath.
Saline springs as at Salzungen, Ischl, Keichenhall, etc.,
are to be found at Droitwich.
The cold sulphur springs of Challes, Enghein, etc., have
their equivalents at Harrogate.
Warm sulphur springs appear to be about the only kind
that are not to be found in this country ; they are not so
widely diffused, and for them we must go abroad, many
existing on the borders of the Dead Sea.
No hardship should, however, be experienced by those
THERMAL AND MINERAL WATERS 271
who, by force of circumstances, have to take their British
remedies with British scenery, for the few instances quoted
show how blest we are here, if we will only avail ourselves
of the benefits around us and leave our more wealthy
brethren to combine foreign scenes with foreign waters.
Mineral springs are found on the Alpine heights, under
the snow in the Himalayas, and arising from the bottom
of the ocean, as at Baiae and Ischia.
The warm salt springs of Caldas de Mombay, near
Barcelona, have a temperature of 158, and Jemez Waters,
in New Mexico, carry a temperature of 168. Mineral
springs abound in Austria in greater numbers than in any
other country, there being no fewer than 1500, the prin-
cipal being Carlsbad, Marienbad, Franzenbad, Teplitz,
Pullna, and Seidlitz.
At Kissingen, Bavaria, there is a salt spring which rises
to a height of 58 feet above ground from a depth of 1878J
feet ; this is not a natural spring : the boring was com-
pleted on 12th August 1850.
Indifferent waters, at a temperature of 85-95 F., are
found in the Pyrenees (Panticosa), 5110 feet above sea-
level.
Warm earthy waters 93 to 104 F. are found at an
altitude of 4400 feet at Leuk, Switzerland, and Bormio, in
Northern Italy.
Iron waters at St Moritz, Switzerland, at an altitude of
4464 feet.
Warm sulphur springs 113 F. at an altitude of 4100
feet at Bareges and other spots in the Pyrenees.
Alkaline waters 100 to 125 F. at Mont Dore" and
Bourboule (Auvergne), 3300 and 2800 feet in altitude re-
spectively. Also at 4000 feet in Lower Engadine (Trasp).
Many mineral springs have their waters heavily charged
with soluble salts. Where lime is present it is kept
272 WATER : ITS ORIGIN AND USE
soluble by the carbonic acid gas ; when this is given off by
heat or exposure to air, the lime is deposited in the form
of rock.
At San Filippo, in Tuscany, there is a spring of this
description, which deposits lime at the rate of 12 inches
a month ; this spring has formed a bed of rock 250 feet
thick, 1 miles long, and mile broad. The well-known
building-stone called travertine or Tiber stone, largely used
in Italy, is a mineral- spring deposit, being a concretionary
limestone, hard and semi-crystalline. The Colosseum and
a large proportion of ancient and modern Eome was built
with it.
The Carlsbad springs produce a considerable amount of
matter every year. Dr Schuman Leclercq of Carlsbad,
in a letter to the writer, states that there are fifteen of these
springs and that their combined yield is 870,000 gallons
of mineral water per twenty-four hours. The " Sprudel,"
with a temperature of 163'6 F., is the principal spring,
which deposits about 110 Ibs. per twenty -four hours of
" Sprudel Sinter." Each of the other fourteen springs has
a distinct temperature, varying from 47'6 F. to 147 '6
F., no two of them being identical. The waters of these
springs also contain a considerable amount of calcium
carbonate and carbonate of magnesium (a portion only of
which is deposited).
The hot springs and ponds of Tuscany deposit native
boracic acid called sassolin, which was first discovered in
the province of Florence, at a place called Sasso.
Springs of chloride of sodium exist in the Eastern
Cordilleras, and stretch from Princeima to the Llanoes de
Meta, a distance of 200 miles.
Water heavily impregnated with sulphur, from the
sulphur springs of Iceland (Krisuvik), is worth a passing
notice in our story.
THERMAL AND MINERAL WATERS 273
In many places the surface of the ground is covered
with a crust of almost pure sulphur 2 or 3 feet thick.
The water from which this sulphur is derived is ejected
with a hissing noise, to a height of from 5 to 8 feet,
accompanied hy steam impregnated with sulphuretted
hydrogen and sulphurous acid gas. The sulphur was at
one time mined for export, the surface clay containing
15 to 90 per cent, of sulphur.
These springs are due to the infiltration of water on vast
beds of pyrites, for it is found that after a continuance of
wet weather, the amount of steam, etc., issuing from the
springs is always greater.
In Chili there are numerous thermal saline and
sulphurous waters, at temperatures from 50 to 212 F.,
at an altitude of from 1150 feet to 10,690 feet.
Bagneres-de-Luchon, a small town in the province of
Haute-Garonne, at the foot of the Pyrenees, is celebrated
for its sulphurous thermal springs, which have a tempera-
ture of 88 to 180 F.
Some springs, like the " Wildbader " of the Continent,
and the Malvern Springs, are purely thermal ; there is an
entire absence of dissolved solids, the water being pure,
clear, soft and limpid.
Many waters are found to be naturally impregnated
with carbonic acid gas, which is found to aid digestion.
Some artificial table waters contain only carbonic acid
gas, others but little dissolved solid matter in addition.
Figuier says : " The last phase of volcanic activity is the
disengagement of carbonic acid gas, without any increase
of temperature.
" In places where the continued emanations of carbonic
acid gas manifest themselves, the existence of ancient
volcanoes may be recognised, of which these discharges are
the closing phenomenon.
18
274 WATER : ITS ORIGIN AND USE
"This is seen in the most remarkable manner in
Auvergne, where there are a multitude of acidulated
springs; that is to say, springs charged with carbonic
acid."
The greatly esteemed selters water, more commonly
known as seltzer, is a natural mineral water found in the
village of Niederselters, in the German province of Hesse-
Nassau and elsewhere; it contains chiefly carbonic acid,
carbonate of soda, and common salt. Artificial substitutes
for this water are largely manufactured.
Apollinaris is a natural aerated acidulated soda water,
obtained from a spring in the valley of the Aar, near the
Rhine : this water is in great demand as a beverage.
CHAPTER XI
RIVERS
" Ten thousand rivers poured at his command,
From urns that never fail, through every land ;
These like a deluge with impetuous force,
Those winding modestly a silent course."
WILLIAM COWPER.
A KIVER system consists of a number of small streams or
tributaries that drain a certain area, united and forming
one main stream, and the land drained thereby is called
the river-basin, the watershed being the higher ground
which divides or parts the basins of neighbouring river
systems from one another, each river system discharging
its water into the sea independently.
Rivers are among the most important of the natural
features of our globe. As important highways of com-
munication they are only equalled by the sea, and are
intimately connected with the history and condition of
mankind.
For transport of merchandise to inland towns their
utility is also unequalled, and tidal rivers especially form
in this aspect one of a country's greatest assets.
Rivers are the vehicles by which the atmospheric pre-
cipitates (rain, etc.) falling on the land are returned to the
sea. Rivers formed the most important consideration
in past ages, in the selection of a site for a settlement by
our ancestors as may be noticed on reference to a map.
275
276 WATER : ITS ORIGIN AND USE
This was, no doubt, a very wise move on the part of man ;
unfortunately, however, he no sooner set up his abode
there than he began to contaminate the very stream that
by its purity attracted him. This seemed an unimportant
or far from serious matter to him, and in his ignorance
the fouling of the stream continued, and to our shame let
us acknowledge the fact, that in our wisdom we do likewise
in an exaggerated degree, with the result that many of
our beautiful rivers, in which at one time salmon thrived,
are now only capable of supporting the commoner fishes ;
and even the delicious oyster may convey to us the
dreaded typhoid, the outcome of sewage contamination.
Charles Kingsley's Clear and Cool describes the present
state of our rivers admirably.
Some rivers have for their source a lake, or flow from
under glaciers.
In the accompanying illustration we see a typical source
of the glacial stream. It is an arch of enormous dimen-
sions, a perfect vault of crystal ice, with its blue horizontal
veins showing distinctly, from which issues the turbid
glacial stream. This arch is in the terminal end of the
Loen Glacier, Norway, and is 50 feet high ; with the aid
of a magnifying glass, groups of persons can be seen at
the entrance.
" Where from their frozen urns, mute springs
Pour out the river's gradual tide."
LONGFELLOW.
The Ehone has its source in and flows from under the
large Ehone Glacier (5581 feet above sea), turbid with
suspended matter, due to the grinding of the glacier on
its bed, to the Lake of Geneva, and on to the sea.
This river, at St Maurice, like the Rhine at Rheineck,
and most glacier-fed streams, is warmer than the air in
winter and colder in summer. In the months of April
Mr H. Wingent.
A NEARER VIEW SHOWING STREAM ISSUING FROM THE ICE-TUNNEL.
ICE-CAVE FORMED IN THE SNOUT OF THE LOEN GLACIER (NORWAY)
BY THE GLACIER STREAM.
[To face p. 276.
RIVERS 277
and October the temperatures of air and water are
equal. The Arveiron is another of the many rivers which
arise from glaciers, issuing from an arch of crystal ice
similar to that depicted in the Loen Glacier.
It may interest the reader to know that the influence
of the glacier on the temperature of its stream is con-
siderable, varying of course according to the different
conditions ; but as far as the Rhone and the Rhine, which
are typical of many other rivers, are concerned, its
influence is distinctly recognisable 84 miles from the
glacier of the former river and 99 miles from that of the
latter river.
Streams that originate in the melting of snows are
subject to periodical floods, and at times overflow their
banks and do much damage. Other rivers, which are
formed by rain falling on impervious rock, forming
streams and torrents, cut into the earth, and carry solid
matter into the sea.
Some rivers owe their origin to springs, where the
water falls as rain on a porous stratum, sinks into the
earth, bursting out at a lower level, forming numerous
tributary streams, which unite and form a river.
All rivers, whether swift or slow, are continually
assisting in the work of denudation in proportion to their
size and velocity.
Dr Hutton, referring to this part of the work of rivers,
says : " The summits of mountains are degraded, the solid
and weighty materials of the mountains have everywhere
been carried through the valleys, by the force of running
waters."
" Amidst the din of rushing waters," says Darwin, " the
noise from the stones as they rattled one over another
was audible from a distance. All were hurrying in one
direction : the ocean is their eternity, and each note of
278 WATER : ITS ORIGIN AND USE
that wild music told of one more step towards their
destiny."
The soil that is produced in the destruction of the
solid earth is gradually transported by the moving waters,
and is as constantly supplying vegetation with its neces-
sary aid. This drifted soil is at last deposited upon some
coast, where it forms a fertile country.
Lengrth of Rivers
Before proceeding further with the work of rivers, let
us try to obtain some idea of the immensity of the rivers
of other countries, by comparing them with a river we
all know well, the Thames.
Length in miles.
Thames, England . ... , ..[^ .,., 210
Tagus, Spain , . ... rft . . 510
Loire, France .' ' . . ! . ' . 570
Vistula, Prussia . . . ."'.' 630
Rhine, Switzerland yi ''-'.u< .' '-'> 'ft') 760
Danube, Germany, etc. . ^ !.,; . 1700
Indus, Hindustan , . w< = f ]tt V; . 1800
Volga, Russia ." .. ., . . 2100
Obi, Siberia . . . . ' ^ "'. '. 3000
Congo, Africa . "' ;' !V . "'- ; . ; ' . 3000
Yang tse Kiang, China . -U' 1 '-:^ > . 3200
Nile, Egypt *.,/ 4300
Mississippi, America >-,,'; ,4 .:,,*-- 4400
Amazon, America. ,., . . 4700
Compared with these lengths, the Thames is but a little
rill
When we remember that from Southampton to New
York is about 3000 miles, we may perhaps better compre-
hend the enormous length of such a river as the Amazon.
The length of a river, however, does not always denote
its comparative importance ; the area of its basin would be
VELOCITY OF RIVERS 279
a better guide. The area of the Thames basin is 6000
square miles, that of the Amazon 2,230,000 square miles.
Therefore, although the Amazon is only 23 times as long
as the river Thames, it drains an area 370 times as large.
When we are dealing with the work accomplished by some
of these mighty rivers, it would be as well to bear in mind
that the longest and largest river in the world (Amazon)
drains an area equal to four times that of the whole of
England and Wales.
Velocity of Rivers
The velocity of rivers forms the key to many statements
that will be made in reference to the work and destruction
caused by rivers.
The velocity of a river depends upon the inclination of
its bed, and partly on the volume of the water, and varies
throughout its course accordingly.
The swiftest portion of a river is about one-third of the
way below its surface, the mean velocity about one-tenth of
its depth ; at the bottom the velocity is least.
The velocity of the Thames is 2 to 3 miles an hour,
and the gradient of its bed is 21 inches per mile.
The Nile below Cairo has only a fall of 3 to 4| inches
per mile, while the Arve at Chamonix thunders down a
slope of 1 foot in 616, or 102 inches per mile.
The Danube, in the upper part of its course, falls 26 feet
in 2 miles. The Amazon, in the last 700 miles of its
course, falls only one- fifth of an inch in a mile.
Another remarkable river is the river Jordan, the
largest river in Palestine, whose valley forms one of the
most remarkable depressions in the world. Its several
streams unite in the Bahr-el-Huleh, where it flows rapidly
in a narrow rocky bed into Lake Tiberias ; from here, over
280 WATER: ITS ORIGIN AND USE
a straight line of 70 miles, it manages to cover, by innum-
erable windings, a length of 200 miles, or nearly three
times the distance covered, before falling into the north
end of the Dead Sea. The total fall is 2300 feet, the Dead
Sea being 1292 feet below the level of the Mediterranean
Sea.
Some rivers disappear inio the earth by percolation.
The river Murray (Australia), for example, loses on its
course vast quantities of water in this manner. It is cal-
culated that between Albany and Howlong alone 5,000,000
gallons per day percolate into the earth.
This same river at Mildura contains only 10 per cent, of
the rainfall over its basin, whereas higher up the stream
20 per cent, flows in its channel.
The loss by percolation in this district is so great that
the proportion of the rainfall visible here in the form of
rivers is smaller than in any other part of the world.
In Northern Chili (Copiapo) Darwin discovered a valley,
the bed of a streamlet ; following it up, he came to good
water. He found that, owing to the decrease in the
evaporation and absorption during the night, the stream
flowed a league further then than during the day.
The swiftest river in the world is the Sutlej, one of the
tributaries of the Indus, in the Punjab, British India,
which has its source in a lake in Thibet, at an elevation of
15,200 feet, and pierces the Himalayas through a gorge
with heights of 20,000 feet on either side. At one part
of its course it descends 12,000 feet in a distance of 180
miles.
Several Swiss rivers run through narrow gorges of great
depth. The Via Mala, from Schams to Thusis, in Swit-
zerland, is 5 miles in length and 1600 feet deep, and not
more than 30 to 50 feet in breadth.
We shall now better understand the enormous amount
SOLID MATTER IN SUSPENSION 281
of solid matter these monsters carry to the sea each
year.
Every river has its own peculiarity of some kind. Some
are too swift for transport purposes, as the Hoang-ho;
some are liable to floods, as the Loire ; some are very
shallow, as the Elbe ; others are subject to alteration by
various substances, gathered up by them on their course.
The Salt River of Australia and many others owe their
salinity to the soil over which they pass.
The Vinegar River of New Granada, in Central America,
owes its character to the presence of sulphuric acid in its
water.
In Algeria there is a stream one tributary of which is
strongly impregnated with iron, while another, from a
district of peat marshes, is rich in gallic acid ; and when
the two streams meet they form a river black as ink, for
its tributaries contain the two principal ingredients of
that fluid.
The Hoang-ho or Yellow River of China derives its name
from the yellow earth it carries in suspension. In 1887
this river burst its banks 300 miles from its mouth, causing
a loss of life estimated at at least 1,000,000.
The Tiber has been designated the " Yellow Tiber " from
the yellow mud held in suspension in times of flood.
Solid Matter in Suspension
The foregoing particulars as to the velocity of rivers
lead us to ask what substance water will carry at various
velocities.
At the rate of 3 inches per second it carries fine mud.
,, 6 ,, fine sand.
,, 8 ,, ,, sand the size of
a pea.
282 WATER: ITS ORIGIN AND USE
At the rate of 1 2 inches per second it carries fine gravel.
24 round pebbles 1
inch in dia-
meter.
,, 36 ,, angular stones as
large as an egg.
The reader must bear in mind that stone or other body
when submerged does not require so great an effort to
move it as when it is in the air ; its actual weight under
water depends on its specific gravity; if it be twice as
heavy as an equal bulk of water, it will lose half of its
weight when submerged ; if three times the weight it will
lose one-third ; if four times, one-fourth ; and so on. (See
Specific Gravity.)
The following table gives the amount of mud, etc., in
suspension, in the water of a few of the principal rivers,
in parts per 100,000.
Thames at Battersea . parts per 100,000, solid matter 3
Rhine. ,, 50
Mississippi ... 146
Nile . 160
Ganges ... 194
Tiber 456
Hoang-ho ... 500
(The low figure for the Thames is probably due to the
fact that by the time the water has reached Battersea it
has passed over many weirs, and the greater part of the
solid matter in suspension has been deposited on its way.)
The Ganges, in the 122 days of the rainy season, carries
to sea, a distance of 500 miles, 340,000,000 tons of mud.
Livingstone described the Zingesi, a river 60 or 70 yards
wide and waist deep, as being made up of as much sand as
water.
Water is continually moving stones and soil from higher
MATTER IN SOLUTION 283
to lower levels, where it is deposited and forms deltas, etc.,
to which we shall refer.
Were it not for the rivers, the valleys would gradually
be filled up.
We must not confound suspension with solution: the
former word refers to matter temporarily held up, princip-
ally by the velocity of the water, and continued agitation ;
in solution the solid matter is dissolved in the water.
Matter in Solution
All rivers are carrying matter in solution to the sea.
This is especially the case with rivers which flow through
calcareous districts.
The Thames, for instance, carries down no less than
450,000 tons of salts in solution annually.
The English rivers are now carrying down, in solution,
enough solid matter to lower the general surface of the
country by about 1 foot in 12,000 years. To this must be
added, of course, the amount previously mentioned as in
suspension, so that the total denudation in England from
both causes is about I foot in 3000 to 4000 years.
If so enormous a mass is carried by a comparatively
small river like the Thames, what must be the amount of
matter moved by all the rivers in the world in combina-
tion ? This problem is beyond the powers of the most
profound thinker to imagine.
As a typical instance of the outcome of this removal of
matter by rivers, we may instance the Grand Canon of the
Colorado Eiver, U.S.A., cut by the action of the water. The
river now runs for a distance of 300 miles more than a
mile below the level of the surrounding country, at the
bottom of a trough in places 10 miles wide, with per-
pendicular walls 6200 feet high ! This will give us perhaps
284 WATER: ITS ORIGIN AND USE
a faint idea of the enormous amount of solid matter
carried to sea by this means. The Colorado rises in
the Kocky Mountains and flows down to the Gulf of
California.
If so small a river as the Colorado works such mighty
changes, what are the larger rivers doing in this respect ?
The mighty Amazon alone delivers into the ocean on an
average about 500,000 tons of water every minute, and the
countless streams and rivers all over the globe are
similarly engaged, each bearing its quantum of the solid
earth to the ocean depths.
Here indeed one can see how water carries away the
material from one place, only to deposit it in a new
position, and slowly raises new continents, and so, gradu-
ally but surely, alters the configuration of this apparently
unalterable globe.
" Daily it is forced home on the mind of the geologist,"
says Darwin, " that nothing, not even the wind that blows,
is so unstable as the level of the crust of this earth."
Recession of Waterfalls
The erosive power of rivers is, as we have seen, enormous,
and is only equalled by that of the sea, and as a typical
instance of erosion we will take the recession of the Falls
of Niagara.
These falls at one period were at Queenstown, 7 miles
nearer Lake Ontario than at present. This retrograde
movement is still going on, it being estimated at from 1
to 3 feet per annum ; and considering that nature has an
eternity in which to carry out her work, the day will no
doubt come when the Falls of Niagara are no more, and
there will be one continuous gorge, reaching from Lake
Erie to Lake Ontario, through which the water from the
DELTAS, ETC., FORMED BY RIVERS 285
great American lakes will rush, forming a rapid, about 36
miles long, with a fall of 9 feet per mile.
In addition to the erosion of the bed, huge masses fall
in from time to time through being undermined by
both the running and falling water. In 1818 a mass
covering an area of 9000 feet collapsed. In 1829 two
masses of a similar size fell in. There was also a huge
fall in 1850, and others are also recorded at more recent
dates.
It has been calculated that the time occupied by the
water in cutting this gorge (7 miles long) must have been
anything from 10,000 to 35,000 years.
Professor J. W. Spencer, who has made extensive observa-
tions of the physical history of Niagara, concludes that
" the age of the Niagara Falls is 31,000 years, and of the
river 32,000 years; also that the Huron drainage turned
from the Ottawa River into Lake Erie less than 8000 years
ago. Lastly, if the rate of terrestrial deformation con-
tinues as it appears to have done, then in about 5000
years the life of the Niagara Falls will cease, by the turning
of the waters into the Mississippi."
The great element of uncertainty indicated by these
figures is due to the fact that no one can say definitely
that the rate of erosion has always been constant.
The recession of waterfalls is more or less universal ; the
St Anthony's Fall, in Minnesota, has receded over 900 feet
since the year 1680, in which year it was discovered.
Deltas, etc., formed by Rivers
The Po and the Nile, and the other rivers that flow into
the Mediterranean, bid fair to extend their deltas, so as to
form a chain of lakes by alluvial deposits. The Po has
produced, and is still producing, great geological changes
286 WATER : ITS ORIGIN AND USE
in its basin. The town of Adria, between the Po and
the Adige, now 17 miles inland, was once on the sea-
coast.
Professor Flinders Petrie tells us that in the valley of
the Euphrates, Babylon is now 400 miles from the river's
mouth ; and that sea-shells are found there, and that the
Plain of Babylonia has been extended by silting up, at
least from this point. The rivers of this valley now dis-
charge their waters into the Persian Gulf, some 350 miles
further seaward than in 10,000 B.C., 12,000 years ago,
having added this distance to their course.
The Mississippi and other great American rivers are at
work in a similar way. The delta of the Mississippi has
an area of 12,300 square miles, and that river carries
down and deposits 6,000,000,000 cubic feet of solid
matter per annum. Nearly all the erosion by rain,
snow, frost, glacier, waterfall, and torrent is thus re-
moved by water.
Between Bale and Bingen the Ehine has deposited 6
feet of mud in 100 years, and all rivers are proportionately
energetic.
The amount of solid matter only (not matter in solution)
deposited by some rivers has been calculated as follows :
Cubic feet.
Thames in one year carries and deposits 1,865,000
Mississippi 6,000,000,000
Ganges 6,368,000,000
Danube 67,000,000
Rhone 600,000,000
In Egypt, Memphis, which was on the borders of the sea
in the time of Herodotus, now stands 100 miles inland ; the
intervening land is composed of the disintegrated rocks of
the mountains of Abyssinia, brought down by the Blue
Nile and Atbara. These instances of the wonders of the
DELTAS, ETC., FORMED BY RIVERS 287
power of water could be multiplied indefinitely did
space permit.
The depth of the deposit forming these deltas is some-
what astounding: a well was sunk in the Mississippi
delta as high up as at New Orleans, to a depth of 620 feet,
and the bottom of the alluvial deposit was not reached.
The united deltas of the Ganges and Brahmapootra
cover an area of 60,000 miles, and the bottom is not
reached at a depth of 481 feet ; that of the Po is quite as
thick.
The formation of deltas also of necessity causes a corre-
sponding increase in the length of the river. To give one
instance only, the Shat-el-Arab mouth of the Tigris and
Euphrates has added 100 miles to its course since the
dawn of history.
The Po, Nile, Mississippi, Thames, etc., run between em-
bankments, partly of their own creation, and all periodi-
cally break their banks at times of flood, and would leave
their courses and begin again in a new direction the work
of widening, filling, and raising for themselves new beds
or courses, continually repeating the process, unless pre-
vented by man. The mouth of the Mersey, for instance,
was formerly at Widnes, and was considerably wider and
deeper than the present river at Runcorn.
Gaur, a ruined city in Hindustan, which from 1212 to
1574 was capital of Bengal, was on the old Ganges, and its
decay dated from the change of the course of this river.
Within our own time the Ganges has changed its course :
the main channel formerly passed Eajmahol, but it now
runs in a new direction, leaving this town 7 miles from its
banks.
The change, which is sometimes so gradual as hardly
to be noticeable in a lifetime, is due to the fact that the
water which flows along the concave parts of river-bends
288 WATER: ITS ORIGIN AND USE
has a greater velocity, and therefore exerts more pressure
and friction than that on the convex sides, the consequence
being a loss of soil at the inner side and an accumulation
at the outer side of the bends.
More rapid and destructive changes, of course, are
occasionally due to the bursting of the banks, geological
disturbance, etc., but nature generally carries out most of
her greatest works so slowly as to be scarcely apparent
except to the practical eye of the student of her works.
" At Lima," says Darwin, " is the dry course of a con-
siderable river. But a river has not flowed there for years ;
a ridge had been uplifted across its bed, and the water had
been thrown back and a new channel formed."
The lower Colorado Eiver, in Southern California,
suddenly broke through its banks, deserting its old channel,
and flowed into the Salton Sink, a low-lying area of con-
siderable extent on the borders of the United States and
Mexico. This area is considerably below sea-level, and
has hitherto been desert. Of late years successful irriga-
tion schemes have rendered much of it fertile, and it is
partly in consequence of these irrigation operations that
the Salton Sink has been converted into the Salton Sea.
A dam is now being constructed that will eventually
divert the river, but in the meantime a deep lake some
2000 square miles in area has been formed.
Some rivers, like the Thames, form submerged deltas ;
these form the various sandbanks, etc., requiring a skilful
pilot to navigate vessels in safety through the proper deep
channels, which represent so many different river-mouths.
Every little river is doing its share with its larger
neighbours; matter from the land has been, and is
steadily being, accumulated in all the river-mouths, except
where they are swept by the ocean tides and the matter
is carried far away.
DELTAS, ETC., FORMED BY RIVERS 289
This accumulation has gradually blotted out all evidences
of the former inhabitants of the banks and creeks forming
the river-mouth.
In the Kentish marshes, which are but the result of
silting up, remains of the ancient occupiers of these lands
are continually brought to light ; quite recently I dug out
a coin dated A.D. 286, and this very week one dated
A.D. 296. To some minds these are ancient relics buried
in the river mud ; but, indeed, they cannot lay claim to
antiquity in a study such as this, for we are dealing with
such vast ages that the Roman occupation of these islands
does not take us back any appreciable distance; it was
only as to-day, not even as yesterday, in the history of the
work of water.
Many lakes are gradually being filled up by the sedi-
ment deposited by the rivers which feed them. The Lake
of Geneva, for instance, once extended up the Rhone
valley to St Maurice, if not to Brieg.
Among the widest of rivers is the Congo, which is 25
miles wide in some parts, where vessels may pass and yet
be out of sight of one another.
The Nile is the only great river of Africa which flows
into the Mediterranean: for the last 1200 miles of its
course it has not a single tributary. It drains an area of
over 1,200,000 square miles.
The Zambesi, the only great river of South Africa
which flows into the Indian Ocean, has on its course the
Victoria Falls, one of the greatest in the world.
The Gambia, a river in West Africa, from June to
November becomes a torrent, and rises from 20 to 50 feet,
leaving, as it subsides, a rich alluvial deposit on its shores.
Other results of the work of rivers include the formation
of bars, estuaries, filled-up lakes, lagoons, broads, and the
dangerous sandbanks such as the dreaded Goodwin Sands.
19
CHAPTEE XII
WATERFALLS
NIAGARA
" There's nothing great or bright, thou glorious Fall !
Thou may'st not to the fancy's sense recall :
The thunder-riven cloud, the lightning's leap
The stirring of the chambers of the deep
Earth's emerald green, and many-tinted dyes
The fleecy whiteness of the upper skies
The tread of armies, thickening as they come,
The boom of cannon, and the beat of drum
The brow of beauty, and the form of grace
The passion and the prowess of our race :
And, till the conflict of thy surges cease,
The nations on thy banks repose in peace."
EARL OP CARLISLE.
Formation
A WATERFALL or cataract is the leap of a stream or river
over a ledge or precipice occurring in its course.
It is generally caused by an abrupt change in the
geological structure of the bed over which a river runs.
The Victoria Falls (Zambesi River)
The most remarkable waterfall in the world is without
doubt the one discovered by Livingstone in 1855. He was
the first white man to gaze upon the Victoria Falls, and
the sight moved him more than any other marvel he had
seen.
290
I I
If
THE VICTORIA FALLS (ZAMBESI RIVER) 291
This remarkable river rises at a distance of 1900 miles
from the east coast of Central Africa.
"The upper reaches of the river," says Mr A. J. C.
Molyneux (Geographical Journal, 1905), "from the falls to
its source, a distance of 800 miles, flow through a region of
singular beauty, with navigable waters for the greater part
of the distance, and it might be said that the river runs
along the very top of a plateau 3500 feet in altitude, for
the difference between the water level and the surrounding
country is very slight."
Across the bed of this river is a deep chasm, probably
caused by volcanic action or some other terrestrial
convulsion. This rift in the hard basaltic rock is only
about 80 feet in width at the ends, increasing to 240 feet
in the centre.
Its depth is 256 feet at the western extremity of the
chasm, 343 feet opposite the gorge, and 400 feet in the
gorge, at the approach of the Grand Canon, with a further
descent of some hundreds of feet during its zigzag course
through 40 miles of the Grand Canon, there being a
difference of 1000 feet between the central reaches of
the river and the level above the falls.
The Zambesi River, fully a mile wide, flows peacefully
along, so peacefully that boats can approach with safety
quite close to the brink of the fall. The enormous body
of water, which is collected over an area of 600,000 square
miles, is suddenly precipitated with a deafening roar into
this chasm, escaping through the gorge in an opening only
20 or 30 yards wide, at right angles to the fissure.
The length of the chasm is the same as the full breadth
of the river, viz. 1860 yards, but the fall or lip is sub-
divided by natural features as follows :
Nearest to the western bank, " Leaping Water," 36
yards wide, described as a sloping mill-race, carrying much
292 WATER : ITS ORIGIN AND USE
water when many other portions are dry. Next comes a
break in the fall formed by the island of Barauka, about
200 yards wide, with a fissure passing through it which at
flood-time forms a cascade, which pours its contents also
into the chasm. Then comes the Great Fall, 573 yards
broad, followed by a ledge of projecting rock called
Livingstone Island; then follows the Eainbow Fall,
another rocky ledge; and finally the Eastern Cataract,
similar to that on the western bank.
There is no difference of level in the bed, as is generally
found with other falls, but the river disappears into an open
chasm. This fall is of such magnitude that the better-
known Niagara is completely dwarfed by it.
The process by which nature formed these falls is
apparent, but the time occupied by nature in cutting the
40 miles of canon is a matter for conjecture. In the case
of Niagara its changes have been more or less observed
since 1697, when they were first sketched by Father
Hennepin ; but here there is no such record. But if this
fall receded through the 40 miles of canon at the rate of
1 foot per year, it must have taken about 200,000 years
to cut the channel to its present depth.
The spray from this stupendous fall of 347 feet springs
back into the air to a height of 1200 feet, and the thunder
of its voice can be heard for many miles.
The following lines by James Thomson describe these
falls in forcible language :
" Smooth to the shelving brink a copious flood
Rolls fair and placid, where, collected all
In one impetuous torrent, down the steep
It thundering shoots, and shakes the country round.
At first an azure sheet, it rushes broad,
Then whitening by degrees, as prone it falls,
And from the loud resounding rocks below,
Dash'd in a cloud of foam, it sends aloft
A hoary mist, and forms a ceaseless shower."
THE VICTORIA FALLS (ZAMBESI RIVER) 293
The columns of spray from this fall can be seen 20 miles
off, and at times, when the sun's rays shine on it, a rainbow
is formed : sometimes a complete circle can be seen.
I cannot refrain from quoting a description by Colonel
Molyneux of this interesting phenomenon.
" No mention of these falls would be complete without
some reference to the eternal columns of mist that rise
from the grey depths of the chasm, or to the brilliant
effects of the rainbows that irradiate them.
" As the vast masses of foaming water are precipitated
with the constant roll of thunder into the abyss, they are
broken up into comets' tails, again into spray, and still
again are comminuted into driven mist; the air forced
down with them sets up a current along the canon, and,
ascending in eddies in the chasm, carries with it the
spindrift of the dashing spray, and rises in vapoury columns
far above the falls. Baines, in July 1862, measured the
height by sextant, and found it to be 1144 to 1194 feet
above the bottom of the gorge, these misty clouds rising
higher in the coolness of the early morning than in the
noonday heat, while at the time of high water the spray
nearly envelops the whole length of the falls.
'' From the hill east of the Matetsi Kiver, 40 miles away,
it is especially noticeable against the red gleams of the
sunset as a dark smoky column ; from other places, and
at mid-day, it is of dazzling whiteness.
" At sundown, looking from the west, the ruddy glory of
the after-glow warms it up with orange and tints of flesh-
colour and seemg to quicken it into a blithesome guardian
of the falls.
" It is to this constantly lifting and rolling veil of spray
that the Victoria Falls owes its most peculiar and elusive
charm. No clear and complete view of the depths and
distances of the chasm can ever be obtained. The mist
294 WATER : ITS ORIGIN AND USE
throbs and moves across the scene, dimly revealing and
again hiding innumerable changing sights. Thus there is
always the suggestion of shadowy beauties beyond this
gossamer veil, a feeling that we but just touch the glories
of this earthly paradise, yet shall never grasp and under-
stand them, stay we never so long.
" And amidst this sunlit vapour is born the crowning
spectacle of the falls. At every turn and in every view of
the water, green foliage, and dazzling foam, the glorious
double rainbow follows one, whether in the rich prismatic
colours of the day-time or the neutral tints of the moon-
light. What wonder that the more ancient native term
was " Seonge," the place of the rainbow, for here surely all
the rainbows of the world must come to play in the sun-
light before they follow the thunderstorms across the land
to bless the rain-chilled beasts and birds.
" To the condensing vapour is also due the rich and ever-
green Rain forest and the trees of the Palm-kloof. This
vegetation includes a wealth of ferns, orchids, and palms,
rich treasure for the botanist, who must, however, be pre-
pared for a quick and thorough wetting from the never-
ceasing rain that descends from the foliage above.
"From the grey turmoil of the gorge below rises the
continuous diapason of rumbling thunder, grand chords
and voices are in the air, and under the deep-blue skies
the might and majesty of the falls sink deep into one's
soul. With the homage-paying native who comes here to
worship the deity, we too must feel the mysterious Pre-
sence, and that here, among the greatest of nature's
works, we stand upon the threshold of the 'tablelands
of God.'"
" It is not noon the rainbow's rays still arch
The torrent with the many hues of heaven."
BYRON (Manfred).
By permission of Dr Mill.
THE ZAMBESI GORGE.
[To face p. 294.
NIAGARA FALLS 295
Niagara Falls
The cataract of Niagara, on the channel between Lakes
Erie and Ontario, is only eclipsed in grandeur by the
Victoria Falls. This fall is due to the water passing from
a hard bed of limestone to one of soft shale.
The enormous quantity of water ceaselessly pouring
over these falls comes from some of the largest lakes on
the globe, Superior, Michigan, Huron, and Erie. These
lakes, with their tributary streams, drain an area of more
than 150,000 square miles ; their outflow passes over the
Falls of Niagara, through Lake Ontario and the St
Lawrence River, to the sea.
From Lake Erie to the falls the average depth of the
Niagara Biver is 20 feet, and at some points it is over a
mile wide. At the point where it takes its plunge over
the precipice it narrows down to 3600 feet, or less than
three-fourths of a mile. Between Lakes Erie and Ontario,
a distance of 36 miles, there is a fall of 336 feet, made up
as follows: to the rapids above the falls, 15 feet ; in the
Rapids, 55 feet; over the falls, 161 feet; from the falls to
Lewiston, through the gorge, 98 feet ; from this point to
Lake Ontario, 7 feet.
The enormous amount of water discharging over these
falls has been estimated at 1,500,000,000 cubic feet per
minute (another authority, 2,400,000,000), or in gallons
9,375,000,000 per minute, or sufficient to supply 1
millions of people with water for one year, allowing each
person 20 gallons per day.
The amount of water discharging over these falls in
twenty-four hours, at the lower estimate, would supply the
whole area now under the Metropolitan Water Board for
180 years. For this calculation the report for March 1904
was used. The population supplied was 6,459,048, the
296 WATER: ITS ORIGIN AND USE
amount of water consumed daily being 198,223,000
gallons, equal to 30'69 gallons per head per day (for all
purposes).
If the water passing over this fall in one day will supply
this enormous population for so long a period, the annual
amount passing here must be almost beyond our compre-
hension, and should cause us to admire nature's boundless
prodigality in the matter of water, as well as in all her
other gifts to man. It is estimated that half a million
tourists visit these falls each season. There is little
wonder that so many should be attracted by this gem of
nature's masterpieces.
" Where'er we gaze, around, above, below,
What rainbow-tints, what magic charms are found ;
Kocks, rivers, forests, mountain, all abound,
And bluest skies that harmonise the whole ;
Beneath, the distant torrent's rushing sound
Tells where the volumed cataract doth roll,
Between those hanging rocks, that shock yet please the soul."
BYRON (Ghilde Harold}.
In winter these falls are even more fascinating : here
King Frost can display his power to an unsurpassable
degree. The mists congeal upon everything, tree, ledge,
and rock, covering all with crystal ice and snow, the sun's
rays lighting up this gorgeous spectacle and turning the
crystal icicles into spears of light.
The scene by moonlight must be equally sublime.
The Great Kaieteur Fall, ete.
Another beautiful fall is the " Great Kaisteur " Fall, in
British Guiana, discovered 24th April 1870. Here the
Potaro Eiver falls from a hard on to a soft rock; the
cataract is 822 feet high and 369 feet broad, and is often
encircled by rainbows.
J. N. Bryan.
THE SWALLOW FALLS, BETTWS-Y-COED, NORTH WALES.
[To face p. 296.
THE GREAT KAIETEUK FALL, ETC. 297
Many falls are due to geological faults. The Yosemite
Falls in California are due to this cause.
Another notable waterfall is the Fall of Handeck, near
Meyringen, Switzerland, where the river Aar plunges into
a chasm 200 feet deep.
There are also the falls on the river Montmorency, a
tributary of the St Lawrence, 240 feet high. The cataract
on the Rjukan Fos, in Norway, 900 feet high. The cas-
cade of Gavarnie, in the Pyrenees, 13,000 feet, the loftiest
in Europe, but the volume is small. The falls at Schaff-
hausen, on the Khine, 300 feet broad and 100 feet high.
The waterfall " Tivoli," which provides the power for
generating the electricity for illuminating Rome, is re-
nowned for its beauty.
There is also the loftiest waterfall in Switzerland, the
famous Staubbach, near Lauterbrunnen, variously stated
as having a fall of 950 to 1001 feet; it is, however, a mere
brook, and almost dried up in summer.
The world abounds with beautiful waterfalls, but we
must not overlook those nearer home. The giants of
other lands may eclipse them, but they each have a
beauty of their own. The Scotch and Welsh falls, though
small in comparison, are sublime. The Falls of Foyers,
near the mouth of the river of that name, in Inverness-
shire, which falls into Loch Ness, are described by many
as being the most magnificent in Great Britain. The
upper fall is about 30 feet high, the lower is about
90 feet.
The Rheidol Falls, Devil's Falls, and Swallow Falls are
but three of the many that all visitors to North Wales
endeavour to visit. The writer once saw a splendid rain-
bow in the spray arising from the fall last mentioned,
which proves that even in the smallest of our waterfalls
we may find, on a reduced scale, many of the interesting
298 WATER : ITS ORIGIN AND USE
attractions that are common to the more magnificent falls
that are not within our reach. Here also
" As springing high the silver dew
In whirls fantastically flew,
And flung luxurious coolness round
The air, and verdure o'er the ground."
BYRON (Giaour).
One would imagine that every cataract of importance
had long since been discovered, and that no fresh laurels
were to be won in this direction.
As recently as November 1907, however, Dr Carl
Bovallius made an important discovery in British Guiana.
On an affluent of the river Ireng, near the Brazilian
boundary, at about 5 N. lat. and 60 9' W. long., he
found a waterfall which he describes as " rivalling Niagara
in height, and worthy of ranking with Kaieteur Fall and
the Mount Roraima as one of the greatest scenic treasures
of the country."
This new fall, which its discoverer proposed to name
the Chamberlain Fall, has a sheer drop of 300 feet, and is
some 200 feet in width; it falls over a slightly convex
cliff, showing red, highly polished jasper at places, into an
oval basin which empties, about a hundred yards from the
first fall, over a second, some 30 feet in height.
Mr* Andrei/ L>- lilond.
WATERFALL, RAGAZ, ON THE ROAD TO PFAFFERS, SWITZERLAND.
[To face p. 29
CHAPTER XIII
LAKES
Clear, placid Leman ! thy contrasted lake
With the wide world I dwelt in, is a thing
Which warns me, with its stillness, to forsake
Earth's troubled waters for a purer spring.
BYRON.
Lakes
A LAKE is a body of water lying in a hollow of the land,
and therefore is wholly surrounded by land, having no
direct communication with the sea or ocean, except by
means of a river or rivers. One of the principal functions
of a lake is to arrest, equalise, and regulate the flow of
water to rivers, and so prevent floods.
Formation of Lakes
The origin of various lakes is, to use the words of Lord
Avebury, " a complex question."
Lake basins are due to various causes. All the great
lakes, however, are formed in enormous natural depressions
on the earth's surface, due to change of level ; there are
also lakes formed by embankment as well as by subsidence.
Crater lakes are among the most interesting, occupying as
they do the craters of extinct volcanoes.
Lakes have been formed by the blocking of a stream by
a berg-fall, or by the terminal moraine of a glacier, as in
299
300 WATER : ITS ORIGIN AND USE
the case of Lago d'Alleghe ; or by the drift which a tribu-
tary has swept down, to which cause Mattmark See is due ;
and the level of many Alpine lakes has also been raised
by this means.
Barrier lakes are formed by an embankment being
thrown across a valley through which a river flows, the
accumulation of the waters forming a lake.
Landslips and earthquakes have also been known to form
lakes of this kind.
Other lakes arise through the subsidence of the surface
following on the removal of subterranean masses of soluble
salts by the action of the water ; typical instances have
occurred in Cheshire and Worcestershire, but these are
small and of little importance.
According to some authorities, many of the lakes found
in the vicinity of glaciers do not appear to owe their origin
to the action of ice, the general opinion being that the
action of glaciers is to wear away prominences and not to
excavate and form lake basins; but there are reliable
authorities on both sides, so we will content ourselves with
recording their various opinions on the subject.
Lakes are not due to river action, as some suggest;
the rivers fill them with water, and also tend gradually
to fill them with sediment ; they are due principally to
change of level, though perhaps some are due to glacial
action, the ice forming great hollows, and grinding them
deeper for many ages, until, when the glaciers recede,
they leave behind them mighty lakes as the result of
their erosion.
The only way in which rivers could assist in the forma-
tion of lakes would be by the removal of soluble rock, such
as salt or gypsum.
The English, Irish, Scotch, Scandinavian, and North
American lakes are declared by Sir A. Eamsay to be of
Mm Aubrey Le Blond.
A LAKE ON THE GORNER GLACIER BETWEEN THE ICE AND THE MORAINE.
Mrs Aubrey Le Blond.
A GLACIER LAKE FORMED BY A MORAINE (ARCTIC NORWAY).
{To face p. 300.
CRATER LAKES, ETC. 301
glacial origin , as he has failed to account for their forma-
tion by any other means.
The Lake of Geneva is also attributed to this cause ; it
is 1000 feet deep in the centre.
The altitude of Swiss and Italian lakes varies from
Garda, the largest in Italy which is about 213 feet above
the sea and 902 feet greatest depth, 33 miles long, 3 to 11
miles broad to Brunz, 1850 feet above the sea, and at
places as deep as 2150 feet.
River action could not form these depths, but erosive
action of glaciers has no doubt formed some of them.
Crater Lakes, etc.
Crater lakes are formed, as their name implies, in the
craters of extinct volcanoes, rain and snow having filled
them with water ; among the most interesting of these is
Lake Chala, on Mount Kilimanjaro, a snow-capped
mountain in Central Africa, 19,000 feet high. This lake is
3 miles long by 1 mile wide, and lies 400 to 800 feet
below the level of the summit. Descent to the water is
only possible at one spot. It is fed by melted snow and
rain, it is clear and eool and sweet, contains numerous
fishes, and is frequented by flocks of birds.
The Lake of Campania in Italy, near Baiae, occupies the
crater of an extinct volcano 1| miles in circumference.
It was supposed by the ancients to be the mouth of hell,
from the mephitic character of its exhalations, and its
gloomy surroundings.
There is a crater lake in Oregon which has an average
depth of 1500 feet, and at places is 2000 feet deep. Lonar
Lake, between Bombay and Nagpore, is 1 mile in
circumference and 300 to 400 feet deep.
The most remarkable crater lake is in the Cascade range,
302 WATER : ITS ORIGIN AND USE
Southern Oregon : it is 7 miles long by 5 miles wide, and
its depth varies from 853 feet to 1996 feet. It is elliptical
in shape and is encircled by cliffs 900 to 2200 feet high ;
the colour of the water is a beautiful ultramarine.
In the centre of this lake is a cone 600 to 700 feet high,
which leads to the conjecture that at some period the
whole of the top of this mountain was blown off, leaving a
portion of the cone projecting in the centre, as occurred
during the eruption of Toniboro, in the island of Sumbawa,
when from this sharply defined cone, 9000 feet high, the
upper 5000 feet were blown away in a single night. This
occurred in 1815, and the sky was darkened for about a
million square miles.
Lake Nemi, 17 miles south of Rome, 5 miles in circum-
ference, occupies, without doubt, the crater of an extinct
volcano.
The Lake of Tiberias (Sea of Galilee), in Palestine, is
generally supposed to have been formed by subsidence
and volcanic activity, its surface being 682 feet below the
level of the Mediterranean Sea.
There are many other remarkable lakes, such as the
fresh-water lake of Lusch, on the Heinzenberg, 6391 feet
above the sea. This lake has no visible outlet, the surplus
water percolating away through hidden channels.
In California the overflow of the beautiful Lake Tahoe,
on the summit of the Sierra (alt. 6200 feet), passes off by
means of the Truckee River, and enters Pyramid Lake,
where it sinks or disappears by evaporation.
Lake Baikal (Abundant Water), the great fresh-water
lake of Siberia, 12,500 square miles in area, 1360 feet above
level of sea, though fed by several rivers, has only one
visible outlet, the Lower Angara.
We have frequently heard of intermittent springs, but a
periodic lake is, I believe, a rare phenomenon.
CRATER LAKES, ETC. 303
The Eichener See, near Schopf heim, in the Black Forest
(Geographical Journal, 1900), is a remarkable lake of this
description. It makes its appearance sometimes after
intervals of several years, at others several times in the
same year. At the last high- water period, 1882-3, it
reached a depth of 11 feet, and persons have often been
drowned in it. The lake owes its origin to the swelling
of the underground watercourses which traverse the
" Muschelkalk." The high level is reached only when
some weeks have elapsed after the fall of heavy rain.
In the Life of G. A. Henty, already referred to, we find
mention of a periodic lake "Zirknitz," near Adelsberg,
which is emptied usually once a year, when, in the absence
of the water, the natives grow in its fructifying mud, crops
of coarse grass, millet, and buckwheat.
" About midsummer the waters of the lake begin to
shrink, growing lower and lower, and so rapidly that, after
about twenty days in July, the lake is empty, remaining
so till September or October, according to the season."
The lake, however, sometimes remains full for three or
four years together. Space will not admit of a detailed
description of the many interesting features of this strange
lake, or of the fish it leaves behind, when it dries up, thus
supplying the natives with at least a portion of their food ;
how it empties and refills, having no apparent inlet or
outlet, other than innumerable holes connecting it with
the caves, grottoes, and reservoirs in the mountains ; or how
it sometimes fills in twenty-four hours. I can only refer
the reader to Mr Manville Fenn's most interesting book.
Another remarkable lake mentioned by Mr A. T.
Drummond (G-eographical Journal, 1900) exists in Canada.
This is a lake with a subterranean inflow, probably
derived from a source 25 or 30 miles distant. It is
situated on the top of a cliff 180 feet high, on the south
304 WATER : ITS ORIGIN AND USE
side of the Bay of Quinte, an arm of Lake Ontario, and is
described as a fresh- water lake 1 miles long, f mile wide.
Though shallow, in the bottom of the lake is a great rent
nearly a mile long by J mile wide, 75 to 100 feet deep;
this rent, it is assumed, accounts for the subterranean
connection with the distant source of its supply.
Surface Level of Lakes
The beds of many of the English lakes are below the
present sea-level ; among them are :
Coniston . .143 feet above sea, 184 feet deep.
Windermere . . 130 220
Wastwater . . 200 258
These are but as pools compared to such lakes as
Maggiore (Italy), whose surface is 636 feet above the
sea, and its bottom about 1500 feet below sea-level ; it has
therefore a depth at places of over 2000 feet.
The surface level of some of the larger lakes will no
doubt be of interest, the figures representing feet above
the sea: Thun 1856, Geneva 1150, Como 653, Superior
and Michigan 627, Huron 595, Erie 565, Ontario 234. The
last five form a remarkable chain of lakes, having a total
area of 90,000 square miles of fresh water. They form
part of the national drainage system of North- West America,
discharging into the Atlantic via the Niagara Falls, through
the river St Lawrence.
Among the highest we have Titicaca, in the Cordilleras
of South America, which is 12,500 feet above the sea ; it
measures 90 x 30 miles, greatest depth 924 feet, bottom
temperature 54 P 6 F.
Lake of Chinchay-cocha, in Peru, 36 miles long, 7 miles
wide, is 13,000 feet above the sea.
The reader will probably ask which lake has the lowest
SALT LAKES 305
surface level, and which is the deepest ; these two questions
are answered as follows :
The deepest Baikal : surface, 1360 feet above sea-level ;
bottom, 2720 feet below sea ; total depth, 4080 feet.
The lowest the Dead Sea: surface level, 1292 below
sea ; greatest depth, 1308 feet.
Salt Lakes (Formation of)
Nearly all lakes are fresh, because their waters are
continually changing.
Salt lakes are formed when the amount of water flowing
into the lake is equalled by the evaporation from the
surface, there being no overflow or outlet, such as the
Dead Sea or the Great Salt Lake in Utah ; the saline
materials which have been dissolved out of the soil do
not disappear by evaporation, and therefore accumulate
in the lake.
Even here life is possible, for Darwin tells us that an
annelida, a kind of worm, exists in brine, and may be
seen crawling among the crystals of sulphate of soda and
lime on the borders of the salt lakes of Patagonia, and
that " every part of the world is habitable, whether lakes
of brine or those subterranean ones hidden beneath
volcanic mountains, warm mineral springs, the wide
expanse and depths of ocean, the upper regions of the
atmosphere, and even the surface of perpetual snow all
support organic beings."
The Dead Sea
This most remarkable lake is 46 miles long, its mean
width averages about 8| miles, and its maximum depth is
1308 feet ; it receives several other tributaries besides the
river Jordan, but has no outlet, and it does not require
20
306 WATER : ITS ORIGIN AND USE
any, as the evaporation even exceeds the amount of water
received, although the surface in the rainy season stands
10 or 12 feet higher than in the dry season, and the lake
is therefore getting smaller and salter.
The Dead Sea lies deeply embedded in lofty cliffs of
limestone, and its shores present a scene of indescribable
desolation and solitude, encompassed by the desert sands
and bleak, stony, salt hills; sulphur, rock-salt, lava, and
pumice abound along its shores. The water is intensely
bitter as well as salt. Chlorides of sodium, magnesium,
and calcium are the chief ingredients, and its density is so
great that the human body will not sink in it.
The presence of so much saline matter is accounted for
by the washings of the salt range of Sodom and the
brackish springs along the shore, as well as by the exces-
sive evaporation.
The following is the analysis of the water, which has a
specific gravity of 1*227, at a depth of 1110 feet :
Chloride of calcium . . * t t 3*107
magnesium . . . 14-889
sodium . . . 7 '855
potassium . . . 0-658
Sulphate of lime . . 0-070
Bromide of potassium . . . 0-137
26-716
A friend has given the writer a short description of his
experience of a swim in this salt lake, which is worth
repeating.
" The Dead Sea is rightly named : there is nothing but
death, in the shape of salt and sand, for miles round its
coasts. But have a dip in its waters, and you feel lively
enough ; in fact, you cannot sink. This buoyancy of its
water is due to the enormous quantity of mineral salts
held in solution : from 25 per cent, to 28 per cent, is said to
GREAT SALT LAKE, UTAH 307
be the quantity. Bathing here is particularly unpleasant
if there is any wind, the salt being extremely irritating to
the eyes ; for hours also after your dip, your person is left
uncomfortably sticky from the salt.
"The sensation in the water is also curious, the only
comfortable position is floating, or swimming on the side.
With the breast-stroke your legs and shoulders are forced
up high, with the consequence of a feeling that the small of
your back is going to break.
" Situated some 5 to 8 miles from the modern Jericho,
with a most barren and bleak desert around it, with salt
in the air, in the sand, and in the water, this inland sea
cannot be said to be an ideal bather's paradise."
The peculiar sensation referred to will be easily under-
stood when we remember that the specific gravity of the
water is 1*24, that of the human body being '89.
Archimedes discovered over 2000 years ago that " a
body immersed in a liquid is buoyed up with a force equal
to the weight of the liquid it displaced."
Therefore a man would have to displace a greater bulk
of water than that of his body before he could sink ; he
would thus be thrust upward, until a part of his body,
equal to the difference between the two specific gravities,
was above the water.
The specific gravity as compared with other water is :
Specific Weight of
gravity. a cubic foot.
Dead Sea . . . 1'240 77-5 Ibs.
Mediterranean . . 1-029 64-3
Rain water . . . 1-000 62-5
Great Salt Lake, Utah, etc.
The Great Salt Lake, to the west of the Rocky
Mountains, North America, measures 70 miles from north
to south, and 48 miles from east to west.
308 WATER : ITS ORIGIN AND USE
It has an area of 1900 square miles, and, unlike the
Dead Sea, is 4200 feet above the level of the sea. Its
maximum depth is only 56 feet, and it is subject to a
yearly rise and fall like the Dead Sea.
Its water contains 6| times more than the average
solid constituents of sea-water, being almost as heavily
impregnated (22*4 per cent.) as that of the Dead Sea
(24*5 per cent.), and the salt is so pure that it is used in
the city without artificial refining.
Its waters are so salt that 5 gallons water yield on eva-
poration 14 pints of salt, and its shores are whitened with
the salt ; and I need hardly state that it contains no fish.
This lake was at one time a fresh-water lake. Time
and geological changes have altered the drainage area
supplying it, so that now the evaporation more than
equals the amount of water running into it, and it has
become salt.
The opinion now prevails almost universally among
scientists that this body of water, which is 1000 miles
inland, is drying up, and is certain, within the course of
half a century, to disappear from the map.
The salt lakes of Africa are Assal Lake, which, like
the Dead Sea, is 600 feet below the level of the Red
Sea, and Schott Kebir, south of Tunis, a salt lagoon 100
miles long, which dries up in the summer, exposing its
bed, which is found to be thickly encrusted with salt;
this lagoon lies several feet below the level of the
Mediterranean.
In the shallow pools bordering on the Caspian there is
a constant deposit of salt. An overflow of this mighty
lake, called the Karabughaz, receives through a channel
150 yards wide, 5 feet deep, where flows a continuous
stream, 350,000 tons of salt daily, and it has become so
salt that the seals have forsaken its barren shores.
GREAT SALT LAKE, UTAH 309
The percentages of salt in seven principal salt lakes
are given in the following table :
Specific Percentage
gravity. of salt.
KokonorSea . . . 1-00907 I'll
Aral Sea . . .No record 1'09
Caspian (open) . . 1 '001 06 1'30
Caspian (Karabughaz) . 1-26217 28'5
Urumieh Sea . . . 1 '17500 22'28
Dead Sea . . . 1-2400 22'13
Suez Canal (Ismailia) . 1-03898 5'1
Some of the fresh-water lakes of North America were
originally salt lakes, but the reverse action has taken
place; the geological conditions were altered, and the
lakes received a larger supply of fresh water, which
circulated through them, and so their water speedily lost
its salinity, and they became, as we now find them, fresh-
water lakes.
There are many other salt-water lakes, though not
nearly so salt as the Dead Sea and Utah Lake. The Sea
of Aral, in Asia, is a salt-water lake 26,650 square miles
in area, 160 feet above the Mediterranean ; this lake has
also no outlet.
The Caspian Sea, the largest isolated sheet of water on
the globe, has an area of 120,000 square miles, its maximum
depth being over 3200 feet, and its surface 85 feet below
the Sea of Azof ; it is a salt lake also, and has no outlet.
" On account of the excess of evaporation," says Dr Mill,
" the surface of this lake is now 90 feet below sea-level,
and its salinity would be greater but for the peculiar
circumstance that its shelving shores and the wide, shallow
inlet of Karabughaz act as natural salt-pans, evaporating
the thin layer of water covering them, and causing a
deposit of crystalline salt which is thus being gradually
withdrawn from solution, while part of the evaporation
310 WATER : ITS ORIGIN AND USE
is made good by a continual supply of fresh river
water."
In Russia we have Lake Balkash, 330 miles long, area
8500 square miles, nowhere over 80 feet deep, extremely
salt, and with no outlet. It was formerly much larger, and
is still decreasing.
Lob Nor, a lake in the Desert of Gobi, is also without
an outlet.
Aullagas, a salt lake of Bolivia, has only one perceptible
insignificant outlet, and what becomes of the surplus water
it receives is unknown.
Gokcha, a lake in Russian Armenia, 540 square miles
in area, 6400 feet above the sea, receives its water from
several streams, but has no outlet of proportionate size.
In Australia there are many salt lakes which have no
outlet Eyrie, Torrens, Gardener, and Amadeus besides
many smaller ones, in all of which the size and saltness
vary with the seasons. In dry seasons Torrens is merely
a salt-marsh.
On the borders of the Mediterranean are several salt
lakes, of which Menzaleh is the largest. The Suez Canal
passes through this and several others.
From these instances we might naturally conclude that
all lakes not having outlets are salt lakes, but there are
exceptions.
Lake Tchad, in the Soudan (Central Africa), having an
area of about 20,000 square miles, has no outlet ; it is a
fresh-water lake, in which abound fish, turtles, etc. This
lake also varies in size according to the seasons.
Dried-up Lakes
In many parts are found the dried-up beds of lakes that
have long since disappeared.
AREA OF LAKES 311
The Desert of Gobi, the " Sand Sea " of the Chinese, in
Eastern Asia, which has an area of 360,000 square miles,
is said to have been once an inland sea. Its general
elevation, however, is now over 4000 feet above the sea.
In Egypt a dried-up lake basin called Moeris exists ;
this formerly contained a body of water 450 miles in cir-
cumference and 300 feet deep.
Many of the mud-flats, the remains of ancient lakes
and dried-up valleys of the Sierra in California, prove by
the terraces surrounding them that water was formerly
much more abundant and stood at higher levels than at
present.
In Southern Italy, in the province of Aquila, is an
example of an artificially dried lake. Here Lake Fucino,
11 miles long, 5 miles broad, 2181 feet above sea-level,
was drained by means of a tunnel constructed by Emperor
Claudius, the water being carried into the Garighano, thus
reclaiming 36,000 acres of rich arable land.
Area of Lakes
The size of our English lakes, as compared with those
of other countries, will help us to grasp some idea of
their immensity ; the figures given here are square
miles.
Windermere, 10 ; Lomond, 45 ; Lucerne, 40 ; Neagh,
in Ireland, 150 ; Maggiore, Italy, 150 ; Constance, Switzer-
land, 210 ; Geneva, Switzerland, 331 ; Wener, Sweden,
2306 ; Ladoga, Russia, 7156 ; Michigan, America, 26,000 ;
Superior, in America, 32,000; and Caspian, in Europe
and Asia, 170,000.
When we are told that the Caspian Sea is about 17,000
times larger than Windermere, and that Lake Superior,
the largest expanse of fresh water in the world, is as large
312 WATER : ITS ORIGIN AND USE
as Ireland, we can get an idea of the enormous extent of
these vast bodies of water.
Temperature of Lakes
The temperature of lakes may vary at their surface from
68 F. to 77 F. in summer according to the atmospheric
conditions, decreasing as we descend to a depth of about
400 feet from the surface, after which it is found that
the variation of temperature with increasing depth is
quite insignificant ; in a lake 1000 feet deep the tempera-
ture at 400 feet is only one- or two-tenths of a degree
higher than that at the bottom.
The Lake of Geneva in autumn is 78 at the surface and
41 at 950 feet ; in February the surface temperature is
only 42, while at 1000 feet down it is still 41 : so in all
deep lakes, there is a body of water beyond the influence
of the sun's rays.
The coldest temperature at the bottom appears to be
Lake Constance, 3 9 '6 F., the surface temperature being
64*6 F. This lake is only 394 feet maximum depth.
At the bottom of Loch Lomond there is at all seasons
a constant temperature of 42, which is the mean tempera-
ture of the atmosphere during the cold half of the year, the
mean annual temperature here being 47 '8. In winter the
surface water of lakes cools, contracts, sinks, warmer water
rising to take its place; this circulation goes on until
the whole lake cools down to 39 F. (if fresh water), the
maximum density ; further cooling causes the water to
expand, and it remains at the surface, forming a thin sheet
of ice. Thus no ice can form until the whole body of
water has reached 39 F., and it is for this reason that
deep lakes rarely freeze, except in countries where long
and severe winters are general
COLOUR OF LAKES 313
Colour of Lakes
Lakes differ greatly in colour. The depth of the intense
blue of the Lake of Geneva is almost unequalled in any
waters except the Mediterranean and the Grecian Archi-
pelago. This fact was apparent to Byron, for in Childe
Harold he says,
" By the blue rushing of the arrowy Rhone
Or the pure bosom of its nursing lake."
This unusual blueness is of greater transparency in
winter than in summer. From October to April a white
disc is visible at a depth of 41 feet ; during the summer
months at 21^ feet only, the thermal stratification of the
water keeping in suspension a greater quantity of dust
and organic particles.
The Lake of Lucel, in the Val d'Herins, is, however, bluest
of all. Glaslyn, on Snowdon, is indigo. Some lakes are
bluish green, green, or yellowish, while others are quite
colourless.
The bluest lakes are those that are the purest. The green
lakes contain in solution a minute quantity of vegetable
matter or peat. The varying tone and tint is also due to
the light of the sun and reflection of the sky.
CHAPTER XIV
OCEAN AND SEA
THE SEA
Roll on, thou deep and dark blue ocean roll !
Ten thousand fleets sweep over thee in vain ;
Man marks the earth with ruin, his control
Stops with the shore ; upon the watery plain
Time writes no wrinkle on thine azure brow.
Such as Creation's dawn beheld, thou rollest now,
Thou glorious mirror, where the Almighty's form
Glasses itself in tempest ; in all time,
Calm or convulsed, in breeze or gale or storm,
Icing the pole, or in the torrid clime,
Dark-heaving, boundless, endless and sublime,
The image of Eternity."
BYRON.
THE sea, unlike the land, is unaffected by time. It was the
same a million years ago as it is to-day. The mountains
disappear, continents alter their shape, rise and fall, islands
may arise or be submerged, but the sea remains the sea
always.
" We say firm as a rock, old as the hills. But no rock is
firm, and no hills are old : granite crumbles away and hills
are carried into the sea. The ocean, however, is outside
time. If we were to look back 100,000 years, the land
would show strange changes ; but the ocean would look
just as it does to-day " (Lord Avebury).
" The adjustments," says Dr Buckland, " of the relative
quantities of sea and land in such due proportions as
to supply the earth by constant evaporation, without
314
OCEAN AND SEA 315
diminishing the waters of the ocean ; and in the appoint-
ment of the atmosphere to be the vehicle of this wonderful
and unceasing circulation ; in thus separating these waters
from their native salt (which, though of the highest utility
to preserve the purity of the sea, renders them unfit for
the support of the terrestrial animals or vegetables) and
transmitting them in genial showers to scatter fertility
over the earth, and maintain the never-failing reservoirs
of those springs and rivers by which they are again
returned to mix with their parent ocean; in all these
circumstances we find such evidence of nicely balanced
adaption of means to ends, of wise foresight, and benevolent
intention, and infinite power, that he must be blind indeed
who refuses to recognise in them proofs of the most
exalted attributes of the Creator."
This forms a fitting introduction to a subject of such
absorbing interest as the sea !
It is found that the sea controls and keeps constant the
amount of carbonic acid in the air, preventing its accumu-
lation, which would be deleterious to health. This gas is
present to the extent of about '04 to '06 per cent. ; the
latter figure should not be exceeded.
The vital properties of the sea-water govern, by a
chemical process, this necessary but dangerous gas, which,
under varying conditions of temperature and pressure, too
complicated for full explanation here, is driven into
carbonate of magnesium in the sea-water; if there is a
deficiency of the gas, the sea in like manner adds the
required amount to the atmosphere, restoring the balance
so necessary to our health. The sea varies but little :
taking one part of the ocean with another, we may safely
conclude that its composition as a whole is constant,
subject only to the very slow progressive millennial
variation.
316 WATER : ITS ORIGIN AND USE
Area of Oceans and Seas
" Thou hast set them their bounds, which they shall not pass ;
neither turn again to cover the earth."
If we deduct the space occupied by Polar ice, the
eternal snows, sandy deserts, sterile mountains, marshes,
rivers, and lakes, the habitable portion of the globe will
scarcely exceed one-fifth of its entire surface.
The oceans and seas comprise the vast body of water
which covers nearly three-fourths, or more precisely eight-
elevenths, of the earth's surface.
The volume of this mass of water is said to be 308,710,890
cubic miles. " Natural philosophers," says Hartwig, " have
endeavoured to calculate the quantity of waters contained
within the vast bosom of the ocean ; but as we are still very
far from accurately knowing the mean depth of the sea,
such estimates are evidently based upon a very unsub-
stantial foundation. So much at least is certain, that the
volume of the waters of the ocean as much surpasses all
conception as the number of their inhabitants or of the
sands that line their shores."
"If we would offer to make a rude estimate," says
Goldsmith, " we should find that all the rivers of the
world, flowing into the bed of the sea, with a continuance
of their present stores, would take up at least 800 years
to fill it to its present height."
Darwin, referring to the immensity of the sea, says : " It
is necessary to sail over the great ocean to comprehend its
immensity. Moving quickly onwards for weeks together,
we meet with nothing but the same blue, profoundly deep,
ocean."
Depth of Oceans and Seas
The bed of the ocean is in many respects similar to the
surface of the land ; it has its plains, hills, valleys, ridges,
DEPTH OF OCEANS AND SEAS 317
and notwithstanding the great transporting power of
water, land-derived materials are not found at a greater
distance than 300 to 500 miles from the shore.
If one could stand on the bottom of the North Atlantic
Ocean, the shores of the earth would be 11,300 feet high,
or as high as Maladetta in the Pyrenees. Submarine peaks
exist in the oceans, some as high as Mount Everest.
Mighty submarine mountain chains also exist as high as
the Alps. Some of these mighty submarine mountain
peaks rise from the deepest depths, as Mount Conway,
which rises from the bed of the South Pacific to a height
of 15,600 feet, and its summit is actually awash, many a
ship having been stranded thereon.
These mountains are no doubt as picturesque as our
mountain ranges, but no eye will ever behold their
splendour.
" The average height of continents is 1000 feet ; the
average depth of the ocean," Professor Wyville Thompson
says, " is not so great as was at one time supposed, and
does not appear to average more than 12,000 feet, but is of
sufficient depth to cover the whole earth, if spread evenly,
to a depth of 8000 feet."
Many writers agree to the figure for average elevation
of the land ; but as to the average depth of the ocean, 2| to
3 miles is quoted, and its mass is said to be 1,300,000
million million tons (which agrees with the previous
calculation of cubic miles).
Calculations as to the mean depths of the oceans have
been made with the following results :
Feet.
By Krummel (1878) .... 11,280
De Lapparent (1883) . . . 13,980
Dr John Murray (1888) . . . 12,456
Heiderich (1891) .... 11,280
Dr Karsten . . 11,472
318 WATER: ITS ORIGIN AND USE
The last-mentioned authority also gives details of the
average depths of the four great oceans :
Feet.
Atlantic Ocean, with Arctic . . . 10,368
Indian Ocean ..... 11,790
Pacific 12,564
Antarctic 4,920
The reader must not test these figures expecting to get
an average of 11,472 feet above stated; the varying areas
have to be taken into consideration as well as the smaller
seas, for the sea with the greatest mean depth is no doubt
the Pacific ; this mighty ocean is equal in area to half the
water of the globe.
In the Atlantic the greatest depths are north of Porto
Rico (28,000 feet ; over 5 miles).
On the eastern margin of the Indian Ocean is the Sunda
or Java Deep (20,000 feet).
Several authentic sounded depths of oceans are given
in the Geographical Journal (vol. vi. p. 477, and vol.
xv. p. 426), as recorded by Commander Balfour, H.M.S.
Penguin, in South Pacific Ocean, lat. 23 40' S., long.
175 10' W. The wire broke before the bottom was
reached. This occurred at 29,400 feet (5 miles), which is
1470 feet deeper than" the previous record, of the Tuscarora
Deep. One hundred miles east of Macarthy Island 30,930
feet was obtained, and specimens were brought up. This
is about half a sea mile deeper than the Tuscarora Deep.
Soundings even deeper than these are reported to have
been taken off the coast of Chili, but with the few excep-
tions given, the depth of the ocean, as far as is known,'
nowhere exceeds 24,000 feet.
The greatest depth found in the North Atlantic was
correctly determined by the Challenger, sounding 23,000
feet (4-4 miles).
DEPTH OF OCEANS AND SEAS 319
Both on the European and the American side of the
Azores are two deep valleys in the ocean bed, 15,000 feet
deep.
A short distance from the edge of the shoal of Bermudas
(about 300 islands) a like depth exists.
In the Pacific the Challenger got soundings of 23,700
and 26,850 feet, or 4 and over 5 miles.
South- Western Pacific, by H.M.S. Penguin, 30,930 feet,
lat. 30 28' S., long. 176 39' W.
The deepest parts of the ocean were in all cases very
near land, and not, as one might expect, in the centre of
these vast sheets of water. One hundred and ten miles
outside the Kurile Islands, which stretch from the
northern part of Japan to the north-east, 27,000 feet has
been sounded.
Seventy miles north of Porto Eico, West Indies, 27,366
feet ; 50 miles from the coast of Peru, 25,050 ; among
the Tonga or Friendly Islands, 27,000 ; near the Ladrones,
26,888 feet; near Pylstaart Island, 26,568 feet.
Other deep soundings in North Pacific were made by
U.S. Survey ship Nero, which discovered a depth of 30,960
and 31,614 feet, and a temperature of 35-9 at 30,420 and
36 at 30,606 feet, and at the bottom 35 or 34 '9 were
obtained. This was named the Nero Deep, and was found
in surveying for a southern route to connect Guam with
the proposed cable from Honolulu to the Midway
Islands.
It is now clear that the greatest ocean depression
extends farther below sea-level than the highest mountain
ascends above it.
Various theories are advanced as to the cause of these
vast depths, but most probably it is more a matter of
elevation of the mass (leaving the hollows) than the
formation of depths.
320 WATER : ITS ORIGIN AND USE
Hartwig, referring to the subject, says: "It has been
found that the greater the depth of the ocean, the swifter
the tide- wave. This affords another means of determining
the approximate depth of the sea bottom. According to
this method, the depth of the Channel between Plymouth
and Boulogne has been calculated at 180 feet; and the
enormous rapidity of the flood-wave over the great open
seas (over 300 miles per hour) gives us for the mean depth
of the Atlantic 14,400 feet, and for that of the Pacific
19,500 feet"; but, as we have seen, these figures are far
too low an estimate.
Pressure and Depth
The pressure at an average depth of the ocean, viz. 2
miles, is as much as 320 atmospheres, and yet there is at
the bottom of the sea an abundance of animal life.
Referring to the pressure of the sea at great depths,
Professor Tait says : " Like fresh water, it suffers but little
compression, notwithstanding at the depth of 1 mile the
pressure is about 1 ton to the square inch, and so on in
proportion ; at the bottom of the deepest ocean about 4
tons to the square inch. At this level 11,000 cubic feet
of air would be squeezed to 22 cubic feet, but 11,000 cubic
feet of water would only be reduced to about 10,000 cubic
feet, the density being only slightly increased ; upon the
pressure being removed, however, the water would return
to its original volume/'
It is stated that 31,614 feet has been sounded near the
Island of Guam ; here Mount Everest could be completely
submerged, and still the waves would roll 2000 feet above
its crest.
At this depth (31,614 x -43) the waters are pressing on
the bottom of the abyss with a pressure of over 13,500
PRESSURE AND DEPTH 321
Ibs. per square inch, a pressure difficult to conceive ; it
would crush like paper the strongest ship.
Notwithstanding this pressure, owing to the incompressi-
bility of water, any substance of greater specific gravity
than water, which will sink in a shallow pool, will sink to
the uttermost depths of the sea. I mention this, for
some people imagine that there is a level and a pressure
in the ocean at which even iron will not sink further.
Shore fishes which inhabit the sea around the coasts do
not usually descend below 1800 feet, and the majority live
close to the surface.
Deep-sea fishes, which inhabit the lower depths of the
sea, are but little influenced by light or temperature, and
are of such construction that they would be unhealthy or
out of their element, metaphorically speaking, in surface
waters. It is assumed that the effect on a fish from the
deeps when brought to the upper water is similar to that
on man in entering the higher atmosphere.
It is found that the rays of the sun do not penetrate to
a greater depth than 1200 feet, as they do not affect a
photographic plate at 220 fathoms (1320 feet). Beyond
this depth is considered the home of deep-sea fish.
At a depth of 3000 feet the temperature would be 40
F., and beyond the influence of the surface temperature;
therefore temperature has little effect on the deep-sea
fishes.
The pressure of the atmosphere on a body at the surface
of the sea is 15 Ibs. per square inch, but under water the
figure would be 1 ton for every 6000 feet.
All deep-sea fishes are carnivorous, for vegetable life
ceases with the depth to which the sunlight penetrates
into the waters.
All marine creatures are subject to a pressure of 15 Ibs.
per square inch for every 5| fathoms in depth ; the tissues
21
322 WATER : ITS ORIGIN AND USE
of deep-sea animals must have a special structure to enable
them to exist at greater depths. If a fish from these
depths rises to the surface, death generally ensues from
rupture through the expansion of the gases on the
reduction of the pressure.
Deep-sea fishes, brought up in the traps set for that
purpose, sometimes arrive at the surface with their stomachs
pushed out of their mouths by the dilation of their swim-
bladders, owing to reduced pressure. If two fishes, one
from deep and the other from shallow water, attack and
seize one another, the one that is carried into the waters
for which he is not by nature constructed is certain to
perish from this cause.
As far as man is concerned, his system will not with-
stand more than an additional 88| Ibs. pressure, thus
limiting the depth he can descend into the sea to 204 feet.
This is a record dive, and death resulted, it is presumed,
not from the depth or pressure, but through a too rapid
ascent to the surface.
Some pearl-fishers reach a depth of 140 feet, and a cele-
brated diver named Lambert salved 100,000 at a depth
of 160 feet.
The Admiralty, however, adopt 120 feet as the limit mark
for their operations.
For experimental purposes two persons have been sub-
jected to an artificial air pressure of 75 and 90 Ibs. respec-
tively, and it is assumed that if great care were taken a
pressure of seven atmospheres (105 Ibs.) might be borne
without causing death ; the risk, however, is great.
Temperature of the Sea
The temperature of the ocean varies greatly ; this is
partly due to abrupt changes owing to currents.
TEMPERATURE OF THE SEA 323
An examination of the records of the sea temperatures
taken by the Challenger renders it highly probable that in
the open ocean the mean daily fluctuations of the tempera-
ture of the surface water amount to not more than 1 F.,
forming a striking contrast to what takes place on dry
land. The extreme ranges of temperature of the ocean
range from freezing point in Polar regions to 96 F. at the
head of the Persian Gulf.
The temperature of the sea under the torrid zone is
always about 78 F. to 81 F. at the surface, diminishing
as the depth increases.
The mean annual temperature of the surface of the sea
around the coast of England is 49 F. ; of the Indian Ocean,
89 F.; of the Red Sea, 94 F.
The maximum and minimum effects of temperature
appear to take place in the water about a month later than
in the atmosphere.
Enclosed seas carry a far higher surface temperature
than the oceans. In the Red Sea 90 F. to 100 F. has been
recorded, but the average is said to be 85 F. in summer
and 70 F. in winter. Here it is estimated that the
evaporation from the surface is from 15 to 25 feet, and
that if it were not for the warm water of the Indian Ocean
always pouring in, it would become a mass of solid salt
in 2000 years. But we are digressing.
Hartwig says : " The equinoctial ocean seldom attains
the maximum warmth of 83 F., and has never been known
to rise above 87 F., while the surface of the land between
the tropics is frequently heated to 120 F. In the
neighbourhood of the line the temperature of the surface
water oscillates all the year round only between 82 F.
and 85 F."
In the Polar seas we find the temperature of the water
higher than that of the atmosphere. Near Spitzbergen the
324 WATER : ITS ORIGIN AND USE
water has never been found below 33 F., and between
Norway and Spitzbergen 39 F., while the air only attained
37 F.
In both temperate and tropical regions the temperature
of the sea at great depths is usually from 36 F. to 38 F. ;
but 32 F. has been recorded, while in the high latitudes
water at 26 F. has been found.
This phenomenon is accounted for by the supposition
that the cold water at the Poles, by reason of its great
specific gravity, sinks to the bottom and spreads through the
ocean basin, proving that in both hemispheres and at all
latitudes the basic waters of the ocean are extremely cold.
The climates of the sea have been systematically
determined, and the extraordinary fact has been brought
to light that the great mass of the ocean water is cold, or
below 40 F.
Even in the equatorial parts of the Atlantic and the
Pacific Oceans a temperature of 40 F. is found within
1800 feet of the surface, while at depths of 15,000 or 18,000
feet the temperature is 32-4 to 33 F. (a little above the
freezing point of fresh water).
Between Scotland and Faroe Islands a temperature of
29*6, or 2'4 F. below the freezing point of fresh water,
has been found, proving that the cold, heavy Polar water
creeps towards the Equator and the upper, lighter, and
warmer water moves away towards the Pole.
Off the coasts of Nova Scotia and Newfoundland the
streaks of warm and colder water of the Gulf Stream alone
vary in temperature as much as 20 F.
South of the Cape of Good Hope the Agulhas current of
about 70 F., diverted by land, pours into a mass of water
to the southward, 25 F. colder.
The depth of warm surface water of the ocean is small.
For example :
TEMPERATURE OF THE SEA 325
The equatorial current between Africa and South
America has a surface temperature of 78 F. ; 600 feet
down it is 55 ; at a depth of 2400 feet, only 40.
The tropical Pacific has a surface temperature of 82 ;
1200 feet down 50; and at about 3500 feet we get a
temperature of 40. Below this depth the decrease in
temperature is very slow.
" Ninety-three per cent, of the whole ocean, or 66 per
cent, of the whole surface of our planet," says Sir John
Murray, "is the vast deep-sea region, and is entirely
removed from the direct influence of the sun, where not
only is there a constant temperature at any one spot
throughout the year, but the sun-rays are believed to be
nearly all absorbed by passing through the 600 feet of sea-
water by which this whole region is overlaid. Of the
entire sea floor 92 per cent, is overlaid with water
having a temperature of under 40 F., while of the entire
surface of the ocean only 16 per cent, has a mean
temperature of under 40 F."
Of the entire bulk of water in the ocean over 80 per
cent, has a temperature under 40 F., and less than 20
per cent, has a temperature exceeding 40 F.
The movement of water at great depths is almost im-
perceptible. Were it not so, the lower water would not
remain so isolated and permanently cold : any general
movement that could be called motion would tend to
equalise the temperatures by causing the lower waters to
surmount any ridges on the ocean bed, and so flow to the
surface.
The bottom of the North Atlantic is nowhere below
35 F. In the South Atlantic, at a depth of 16,800 feet, the
temperature is but a little over 32 F. Ice of the South
Pole does not influence the temperature of bottom water ;
this water, being fresher, though colder, will not sink. Here
326 WATER : ITS ORIGIN AND USE
the water is warmer a few hundred fathoms down than on
the surface.
The lowest temperature of the Arctic Ocean was obtained
by Sir John Boss in Davis Straits, where at a depth of
4080 feet 25 F. was recorded ; but this is doubtful, as the
accuracy of the instruments was questioned.
The temperature of the surface in sandy deserts in the
tropics rises to between 120 and 140 F., rarely more than
200 F., while during the night the temperature sometimes
falls below freezing point.
At Werkojansk, in Siberia, the difference in temperature
between the mean of the coldest and warmest months is
120 F. ; here in February 1892 the temperature fell to
93*6 F. How different are these variations of tempera-
ture from that of the sea !
Colour of the Sea
The sea possesses naturally a pure bluish tint. The
apparently clear water we drink, when seen in large
quantities of sufficient depth, has this beautiful colour;
the factor of quantity is not necessary, it is the depth
through which the light penetrates that gives the effect of
colour. (See Azure Cave, Capri.)
The Bay of Naples is noted for its colour of pure blue,
and the Mediterranean and Arctic Seas are both deep blue
in colour.
The green tint of the North Sea is partly due to the
reflection from its sandy bottom mingling with the blue
water.
The pure ultramarine of the Arctic Ocean is often in
parts turned into a muddy green owing to the presence of
small yellow medusae, so numerous that a cubic inch has
been found to contain sixty-four of these minute creatures.
COLOUR OF THE SEA 327
In the neighbourhood of Callao the Pacific has an olive-
green colour owing to the greenish matter at the bottom,
800 feet deep.
The Eed Sea is so called from the minute algae of a
beautiful red colour which are sometimes present in great
numbers.
In the Bay of Loanga the sea has the colour of blood,
caused by the reflection from the red soil forming the
bed.
The phosphorescent light that the sea sometimes
assumes is also of great interest. Hartwig says : " Many
creatures dredged from the North Atlantic off the west
coast of Ireland, from depths of 500 fathoms, were brilliantly
phosphorescent. In some places nearly everything
brought up seemed to emit light."
Darwin, referring to this, says : " While sailing in the
latitudes of Cape Horn on a very dark night, every part of
the surface glowed with a pale light. The vessel drove
before her bows two billows of liquid phosphorus. As far
as the eye reached every wave was bright, and the sky
above the horizon, from the reflected glare of these livid
flames, was not so utterly obscure as over the rest of the
heavens."
The minute, gelatinous animal that causes this light is
so small that a single bucket of water will contain
thousands, and they exist in such quantities that miles
and miles of the ocean are often turned by them into
sheets of living flames. The number of medusae in the
waters of Greenland seas is so great that in a cubic foot
as many as 110,000 of these minute creatures have been
found.
" Flash'd the dipt oars, and, sparkling with the stroke,
Around the waves phosphoric brightness broke."
BYRON (Corsair).
328 WATER : ITS ORIGIN AND USE
Power of Waves
" O thou vast ocean ! ever-sounding sea !
Thou symbol of a drear immensity !
Thy voice is like the thunder, and thy sleep
Is like a giant's slumber loud and deep."
BARRY CORNWALL.
The sea in its fury is terrible indeed, its power beyond
our comprehension. The roller of a ground-swell 20 feet
high has a pressure of one ton to a square foot, and this
will roll a 5-ton block of stone about like a pebble.
The horizontal pressure exerted by a strong Atlantic
wave is said to be equal to 3 tons to a square foot, and
when confined between the walls of the rocks it acts like
a hydraulic ram.
" The movement of the sea," says Humboldt, "is of a
threefold description; partly irregular and transitory,
depending upon the winds and occasioning waves ; partly
regular and periodical, resulting from the attraction of the
sun and moon (ebb and flood); and partly permanent,
through the unequal strength and rapidity at different
periods (oceanic currents)."
" The strongest storm," says Hartwig, " cannot suddenly
raise high waves : they require time for their development.
The wind blowing over an even sea sets water particles in
motion all over the surface, and this gives the first impulse
to the formation of small waves ; numberless oscillations
unite their efforts and create visible elevations and
depressions. As the strength of the waves rises gradually,
it also loses itself by degrees, and many hours after the
tornado has ceased to rage the mighty billows continue to
remind the mariner of its extinguished fury.
" The turmoil of waters awakened by the storm propagates
itself hundreds of miles beyond the space where the
howling voice was heard, and often during the most
POWER OF WAVES 329
tranquil weather the agitated sea proclaims the distant
war with the elements."
The waves of the ocean have been known to reach a
height from trough to crest of 40 to 90 feet, according to
some authorities. Probably 50 to 60 feet is a more correct
figure. These are termed storm or wind waves, as distinct
from waves set in motion by earthquakes, which have been
known to exceed the former considerably. " The eruption
of Krakatoa (27th August 1883) disturbed the sea, pro-
ducing waves 100 feet high, which rushed upon and over-
whelmed the neighbouring coasts of Java and Sumatra,
stranding ocean steamers, destroying lighthouses, washing
away and drowning over 36,000 persons."
These waves, which were of great length, moved, it is
stated, with the almost incredible velocity of 350 miles an
hour, and their crests were about that distance apart, as
they arrived on the shore at intervals of about an hour.
Similar waves reached Cape Horn, having travelled 7500
and 7800 miles in their course on either side of the South
Polar land, and were only 5 inches above mean sea-level ;
other waves reached the south of Africa, 5000 miles
distant, and were from 1 to 2 feet high.
The maximum speed of storm or wind waves is said to
be 80 miles per hour.
What a helpless thing even a powerful ship is when at
the mercy of such waves ! it is little wonder that the loss
of life by shipwreck is so great.
" Down came the storm and smote amain
The vessel in its strength ;
She shuddered and paused, like a frightened steed,
Then leaped her cable's length."
LONGFELLOW (The Wreck of the Hesperus).
It is not only at sea that the loss of lives is to be
deplored ; many disasters have been caused by storm
330 WATER : ITS ORIGIN AND USE
waves on shore. For instance, at Masulipatam, on the Bay
of Bengal, a storm wave swept over the town in 1864,
destroying 30,000 lives. Many similar catastrophes have
unfortunately occurred.
The depth to which the ocean is disturbed by a violent
gale is said by various writers to be not more than from
300 to 500 feet ; beyond this depth all is still, the most
dreadful hurricanes leave these depths undisturbed.
" There is no sound, no echo of sound, in the deserts of the deep,
Or the great grey level plains of ooze where the shell-burred
cables creep."
KIPLING.
A block of limestone weighing 7 tons is known to have
been carried by the sea a distance of 150 feet. This will
give an idea of its power ; and it has been stated that in
the erection of the Eddystone lighthouse, the engineers
provided in their design for a probable pressure of over
3000 Ibs. per square foot, this pressure being the power
exerted by the waves in a storm.
With such forces continually at work, there is little
reason to wonder at the general destruction going on
around our coasts.
The church at Reculver, in Kent, now on the verge of
the cliffs, was, in the time of Henry VIII., nearly a mile
from the sea.
The Lofoden Islands, on the north-west coast of Norway,
is a typical instance of the manner in which the sea has
swallowed up the solid land. Here groups of rocky
islands are all that remain. It has been appropriately
called " the sea of vanished lands."
These mighty waters and the amount of denudation
they effect is beyond our comprehension : the waves break
continually against the solid earth, until the sea claims it
for its own, forming the rugged coast-lines, with which we
COAST EROSION AT SOUTHWOLD, SUFFOLK.
(The work of one heavy sea.)
THE SAME SPOT TWO DAYS LATER.
(After a second high tide and sea.)
[To face p. 330.
POWER OF WAVES 331
are all familiar. " Here also water appears as the beautify-
ing element decorating inanimate nature with picturesque
forms."
The apparently mighty works of the ocean and seas
enumerated here are but as trifles when we remember that,
without doubt, at a remote period of the earth's history,
Australia was joined up to and connected with Asia, and
that the mighty seas that roll between represent but a lost
continent, claimed by the sea which now rolls over it.
The forces of the sea, however, are not solely employed
in destruction, for, as if by way of compensation, it is con-
tinually adding to some part of our coasts.
Romuey Marsh (24,000 acres) is an example of this
kind. In the ages gone by, this was the open sea, and ships
once sailed over the spot where we can now walk on dry
land.
We have another instance of this kind in the Norfolk
Broads, and there are many similar tracts of land due to
the same process, which begins with the formation of a
bar of sand, drifted by the tide across the mouth of an
estuary ; this is followed by the silting up of the sediment
deposited by the river inside the bar.
In this manner many square acres are added to our
coasts, but the extent of this restoration is small in com-
parison with the enormous destruction worked by the
waves in various parts of the earth.
In a lesser degree the tides do their part in the destruc-
tion and reconstruction of the land.
No description of the wonders of the ocean and sea
would be complete without at least some short reference
to the work of the reef-building Actinozoa and their work
of forming new lands with the carbonate of lime separated
from the waters of the sea. There are three kinds of coral
reef : the atoll or lagoon reef, the barrier reef, and the
332 WATER : ITS ORIGIN AND USE
fringing reef. Some are of considerable extent; the
Suadiva Atoll, for instance, is 44 miles in diameter,
while groups of atolls in various parts of the world cover
thousands of square miles ; barrier reefs are found up to
400 miles long, and fringing reefs of enormous extent are
common.
Keferring to coral islets, Darwin states: "Let the
hurricane tear up its thousand huge fragments ; yet what
will that tell against the accumulated labour of myriads
of architects at work day and night, month after month ?
Thus do we see the soft and glutinous body of a polypus,
through the agency of the vital laws, conquering the great
mechanical powers of the waves of an ocean which neither
the art of man nor the inanimate works of nature could
successfully resist."
While thinking of the awful power exerted by the ocean,
we should also give some consideration to the results and
benefits we derive indirectly from this source. Without
doubt the healthfulness of the ocean is greatly due to its
constant motion, which prevents stagnation and corruption.
How refreshing too is the sea breeze after a storm ! The
endless churning of the waves, every breaker imprisoning
the air, beating it down under its crested head, sends it in
endless repetition rushing through the water to gain the
surface. In this process it becomes washed and purified,
and probably electrified to some small degree : hence the
benefits derived from a sea-trip, where nothing but the
well-washed and purified, invigorating air can be breathed.
Notwithstanding all the benefits we derive from the sea,
it is curious to note what Hartwig says of its composition.
"Besides chloride of sodium (common salt) and other
chief ingredients, the sea-water contains lead, copper,
and silver, and sufficient arsenic to poison every living
thing."
OCEAN CURRENTS 333
Ocean Currents
An ocean current, so called, is a sensible movement of
the water in the ocean in a particular and traceable
direction.
The currents of the Indian Ocean, and of the sea off the
coast of Central America, are produced solely by the
prevailing winds, or trade winds, and they change their
direction twice yearly, with the monsoons. Tt is partly
due to the prevailing west winds that the waters of
the Gulf Stream reach our shores.
These variable currents, propagated by the winds only,
and varying with them, are more correctly described as
" surface drifts." The true ocean current, however, flows
steadily and continuously in a definite direction, keeping
itself distinct from the ocean through which it passes, as
distinct as a river is from the land through which it flows.
The primary cause of the motion of these currents is the
heat of the sun, which raises the temperature of the waters
in the tropical oceans, causing expansion and so setting
up circulation; excessive evaporation and great rainfall
also cause an alteration of density and level, and the
action of the wind, already referred to, also affects the
ocean. All these and many other circumstances, includ-
ing the irregular coast-lines, tend to promote and keep
constant the ocean currents.
Thus we see that every cause which tends to promote
circulation in the oceans, just as in the atmosphere, has
its origin in the centre of our universe, the sun. In
addition to holding the planets in their courses, millions
of miles away, it creates the ocean currents on this
diminutive earth of ours, and fulfils all the important
duties to which we have referred so frequently, and endless
work that has not been mentioned, as well as much that
334 WATER : ITS ORIGIN AND USE
cannot be conceived by us, and it was for this reason that
in the commencement of this book so much time was
devoted to the sun and solar heat.
There are numerous currents in the vast oceans of the
globe, the most celebrated of which is the Gulf Stream,
and we shall refer to it at some length, as it is a typical
example of an ocean current.
The equatorial current is very shallow, only about 50
fathoms. It flows at a speed of 18 miles a day on the
surface, which decreases to 9 miles at a depth of 50
fathoms (300 feet). The surface temperature varies from
75 to 80. At a depth of 100 fathoms the temperature
falls to 60. The temperature of this current is kept
down by the continual rising of the Polar water from
below.
The Guinea current runs at the rate of 30 to 50 miles
per hour, and occasionally at 80.
The contiguous bands of water forming current and
counter-current retain their respective temperatures quite
distinctly ; for it has been found, in crossing these bands
of water coming from different parts, that the temperature
at the bow of the ship has registered 70, while that at
the stern only recorded 40.
"It has been calculated theoretically," says Captain
Wharton, F.E.S., "that winds blowing steadily in one
direction, with the ordinary force of the trade winds, would,
in 100,000 years, by friction between the particles, put the
whole of a mass of water 2000 fathoms deep, not otherwise
influenced, into motion in that direction."
"An instance of the underrunning of one current by
another," continues Captain Wharton, " is brought plainly
to our notice in the North Atlantic, to the east of the great
banks of Newfoundland, where the icebergs borne by the
Arctic current from Baffin's Bay pursue their course to the
THE GULF STREAM 335
southward across the Gulf Stream running eastward.
These great masses of ice, floating with seven-eighths of their
volume under the surface, draw so much water that they
are all but wholly influenced by the undercurrent. A large
berg will have its bottom 600 to 700 feet below the sur-
face. The only reason that these bergs continue their
journey southwards is the action of the cold under-
current."
The Gulf Stream
The hot water of the Mississippi forces the water form-
ing the Gulf Stream from the Gulf of Mexico, where the
tropical sun has heated it to a temperature of 86, through
the Florida Channel. Here its breadth is 60 miles, and it
is about 350 fathoms, or over 2000 feet, deep (other
authorities, however, give 600 feet as the limit of its
depth), and it travels at the rate of 90 to 120 miles per
day (4 to 5 miles per hour). The velocity varies with
the course of the current : within the Florida Channel it
attains a mean of 65 miles per day; off Charlestown,
56 miles ; 36 to 46 off Nantucket ; and 28 miles to the
south of the Newfoundland banks; 300 miles to the
eastward of Newfoundland its movement is hardly
perceptible.
From the Gulf of Mexico, which has a coast-line of 3000
miles, it travels through the Strait of Florida across the
Atlantic. In the Florida Channel its temperature is 34
F. at the bottom, 80 to 84 F. at the surface ; in winter
77 F. But as it travels it gradually suffers a loss of
temperature. Off Charlestown, 75 F. ; off Cape Hatteras,
72 F. ; south-east of Nantucket shoals, 67 F. ; south of
Nova Scotia, 62 F. In winter, therefore, between these
points there is a loss of 15 F. ; in spring, 11 F. ; summer,
5 F. ; autumn, 13 F. In mid- Atlantic it has a tempera-
336 WATER : ITS ORIGIN AND USE
ture of 75 F. Here its breadth increases and its speed
diminishes.
In the Atlantic it divides : one current flows in the
direction of and follows the coast of Africa and is lost in
the equatorial waters ; the other current, millions of times
larger than our largest English river, washes the shores
of England and Ireland, bringing with it some of the
warmth of the West Indies.
Continuing its journey by the coast of Iceland and
Norway, it is lost in the Arctic regions, where, Sir
Archibald Geikie says, "the Gulf Stream is distinctly
traceable by its warmth into the Arctic seas."
The effect of this stream is that it brings us a tempera-
ture 10 F. higher than we are entitled to by our latitude.
Norway by 16 F. and Spitzbergen by 19 F. also benefit by
its genial warmth.
Were it not for this stream, the maritime borders of
Europe, where now a temperate climate prevails, would
be cold and frost-bound, like Southern Siberia and the
coast of Labrador, the latter being in the same latitude as
the British Isles.
How this body of water preserves so high a temperature
even when it reaches the Azores is little short of marvel-
lous, but we have already seen that though water does not
get heated so quickly as other substances, it will retain
its warmth longer. (See Latent Heat of Water.)
Water being able to absorb more heat, without having
its temperature unduly raised, is the only substance that
could possibly bring so enormous an amount of heat such
a distance, and give it out in the process of cooling. It
thus forms a mighty heating apparatus, distributing the
heat of the tropics to lands requiring warmth.
If the surface of the earth were entirely dry land, there
would be no transfer of heat by oceanic or atmospheric
Mrs Aubrey Le Blond.
VEGETATION IN NORWAY, 200 MILES WITHIN THE ARCTIC CIRCLE,
DUE TO THE GULF STREAM.
Mrs Aubrey Le Blond.
ICE-LAKE IN ARCTIC NORWAY, 2000 FEET ABOVE THE SEA, WHERE THE
ICE SELDOM WHOLLY MELTS IN SUMMER.
To face p. 336.
THE POLAR STREAM 337
currents, and the result would be a temperature of about
130 F. at the Equator, while at the Pole it would be 108
F. below zero.
The mean temperature day and night at the Equator is
about 80 F., while that at the Pole is only F., or zero.
Consequently, the effect of the circulation of the ocean
and the atmosphere together is to depress the tempera-
ture at the Equator about 50 F. and to raise it at the Pole
by no less than 100 F., and so make the earth fit for
habitation.
The Polar Stream
Every ocean current has a corresponding counter-
current, in this instance called the " Polar Stream."
This stream flows from the Arctic zone, down Baffin's
Bay, past the shores of Greenland, bearing on its bosom
the icebergs detached from the glaciers and ice-fields of
the Polar regions, bringing them down to the point off the
coast of Newfoundland, where the Polar Stream meets the
Gulf Stream. The difference between the temperature of
the Gulf Stream and this cold current sometimes amounts
to from 20 to 30 F.
During the drift of the Fram across the Polar seas,
exhaustive tests of the temperature at various depths were
carried out. It was found that the surface water of the
entire Polar basin is very cold, seeing that it keeps to
about the freezing point of salt water (29'3 F. to 2912 F.).
When penetrated, however, to a depth of 110 fathoms, the
temperature was from 32'9 F. to 33-44 F. ; this continued
to between 220 and 270 fathoms, after which it sank
slowly, though without reaching the cold temperature of
the surface water. Near the bottom it again rose quite
quickly. Of this Nansen remarks, referring to the
influence of the Gulf Stream in these latitudes : " Great,
22
338 WATER : ITS ORIGIN AND USE
however, was my astonishment when, as far east even as
the sea north of the New Siberian Islands, I found un-
doubted traces of such a warm current."
It is the Polar Stream which brings the bitter cold and
ice of the Polar regions to the coast of Newfoundland in
the summer.
Here, by the greater density due to its low temperature,
the Polar Stream sinks beneath the Gulf Stream, and thus
completes the circuit of these two ocean currents.
The joining of these two streams of different tempera-
tures, and the meeting of the warm air accompanying
the Gulf Stream with the cold aerial counter-current
accompanying the Polar Stream, causes condensation ;
thick clouds of mist arise and hang over the surface of the
sea in these parts, forming a source of great danger to
shipping.
Among the many other ocean currents, each having a
separate course, are the Cold Peruvian, the Equatorial,
the Japanese/ the North African and Guinea, the South
Connecting current, the Southern Atlantic, the Cape Horn
current, Kennel's current, the Arctic and Greenland.
The assistance rendered to navigation by these currents
can only be appreciated fully by those who spend their
lives on the great oceans.
We must also remember that these apparently per-
manent ocean currents are subject to the general
evolution that is going on universally, for Darwin tells
us that during the height of the Glacial Period the
ocean currents were widely different from what they
are now.
If this be so there can be no doubt that the changes
which brought about the present state of things are still
working, and further changes will probably take place as
time goes on.
HARVESTS OF THE SEA 339
Harvests of the Sea
" Lord, how manifold are thy works ! in wisdom hast thou made
them all : the earth is full of thy riches ; so is this great and wide sea,
wherein are things creeping innumerable, both small and great
beasts." Psalm civ. 24, 25.
The harvests of the land must be sown, and the increase
is great ; but it is insignificant when compared with the
unsown harvest of the sea.
The reproductive powers of the fishes are enormous : take
one example only, the cod-fish, the roe of which has been
found to contain 9,344,000 eggs.
The universal distribution of fish is also of interest.
They are found in the lakes at altitudes of 11,000 to 15,000
feet, and in many parts at the line of perpetual snow ; but
the sea is the world's storehouse of this most valuable
food.
In the waters of the sea we get the minute medusa
and the mighty Greenland whale (Balcena mystacocetus),
the largest of all living animals. It has been known
to measure 60 to 70 feet in length by 30 to 40 feet in
girth, and to weigh 70 tons, yielding 30 to 40 tons of
blubber.
Then we have the precious pearls, sponges, corals, and
the seaweed from which we obtain iodine, besides many
other products too numerous to specify.
The work of the ocean in the transport of vegetable
seeds must not be overlooked. It has been found that
very many seeds can endure immersion in the sea for a
long period without damage, and in this way numerous
plants have been introduced into countries many miles
from those in which they are indigenous.
340 WATER : ITS ORIGIN AND USE
Marine Caves
" It is here the sea, which stamps the seal of its might on van-
quished rocks, scoops out wide portals and hollows out deep caverns
in their bosom." HARTWIG.
What work of man's devising can equal that superb
piece of ocean's architecture, Fingal's Cave, in the Isle
of Staffa, which is composed chiefly of basaltic pillars,
resting upon a substratum of rugged rock ?
Here we have a grotto 250 feet long, 53 feet wide at
the entrance, spanned by an arch 117 feet high, with walls
and roof of hexagonal basaltic pillars, even at the farthest
end maintaining a height of 70 feet, the sea having slowly
excavated and formed " a magnificent temple of nature, "
with the sea for a floor, on which boats may venture
safely in calm weather.
Hartwig also tells us of the Azure Cave or Blue
Grotto at Capri, which, owing to its small entrance, the
top of which is only a few feet above the sea, was only
discovered by accident in 1826 by two artists, who were
swimming in the neighbourhood.
Within this narrow portal the cave widens out to
125 feet long by 145 feet broad. All the light that enters
the grotto must penetrate the whole depth of the waters
(several hundred feet) before it can be reflected from the
clear bottom. It thus acquires so deep a tinge that the
dark walls of the cavern are illuminated by a radiance
of the purest azure.
The visitor will find, should he arrive by steamer, a
number of small boats waiting for their harvest. The
day must be a calm one, for the aperture through the
rock into the cave is only large enough to admit a single
boat. The boats are small, and never carry more than
two passengers at a time, one in the bow and one in the
stern. On approaching the entrance, the boatman has to
MARINE CAVES 341
wait for a wave, and time it. With a shout to his
passengers to lie down flat, he gives two short strokes
with the sculls, and lies flat on his back. With a swish
the wave bears us to the mouth, and with a dig of the
oar on the side of the cave we are soon inside.
Inside the cave the colouring is one blaze of azure.
Naked boys are generally waiting for coins to be thrown,
for which they dive, stirring up the water, which sparkles
and scintillates in the light which penetrates from its only
point of access, the entrance.
The grotto of Antro di Nettuno, in the island of
Sardinia, also described by the same writer, must be an
awe-inspiring spectacle.
Here access is only possible on four or five days in the
year, on account of the prevalent adverse winds.
"The first vaulted cavern, forming an ante-chamber
about 30 feet high, has no peculiar beauty ; but on crossing
a second cavern, in which there are about 20 feet of
beautifully clear water, one finds oneself in an intricate
navigation among stalactites, with surrounding walls and
passages of stalagmites of considerable height.
" Proceeding westerly, one reaches another cavern with a
natural column in its centre, the shaft and capital of
which support the immense and beautifully fretted roof,
which reminds one of those in the chapter-house of the
cathedral at Wells, and the staircase in the hall at Christ
Church, Oxford.
" In parts are corridors and galleries 300 and 400 feet
long, reminding one of the Moorish architecture of the
Alhambra; one of them terminates abruptly in a deep
cavern, which it is impossible to descend.
" Some of the ceilings are covered entirely with delicate
stalactites, and the sides with fretted open work, so fan-
tastical that one might almost imagine that it was a
342 WATER : ITS ORIGIN AND USE
boudoir of the Oceanides, where they amused themselves
with making lime lace."
In concluding a graphic description of this wonderful
cave, he says : " Some of the columns are 70 to 80 feet in
circumference, and the masses of drapery, drooping in
exquisite elegance, are of equally grand proportions."
An interesting sea cave formed by the Mediterranean
waves is mentioned by Mr E. A. Martel. He considers
it of unusual size, and unparalleled, at least in Europe.
It is called the Dragon Cave, situate in the island
of Majorca, 8 miles east of the town of Manacor. This
cave has been visited by only two persons since 1878,
and contains about 1 mile of stalactite and stalagmite
galleries and lakes. In September 1896 Mr Martel found
here one of the largest underground lakes known, to which
he gave the name of Lago Miramar, 570 feet long, 100 to
125 feet wide, 15 to 30 feet deep. The vaults and walls
are covered with millions of thin, sharp stalactite needles,
pure and white as ermine.
Innumerable caves of this description exist in many
parts of the world, but are scientifically unexplored at
present.
A passing reference may also be made to the beautiful
fjords or sea lochs in Scotland and Norway. They are in
no way similar to the caves, neither is their formation due
directly to the sea. They are probably of glacial origin ;
at least it is certain that they were formed in remote epochs
of the earth's history.
They are usually of great depth, but barred from the
sea at their entrance by a rocky sill, rising, as in the case
of Loch Nevis, to within about 40 feet of the surface.
The Sogne Fjord, in Norway, well known to tourists, is
4200 feet deep and over 100 miles long.
The water in these fjords is much fresher than in the
HARDANGER FJORD, NORWAY.
SOR FJORD, NORWAY.
[ To face p. 342.
MARINE CAVES 343
sea, owing to the streams that flow into them from the
mountains which rise along their sides. The mixture of
rain water with the sea presents some curious and
interesting phenomena. Fresh water being lighter, keeps
at the surface ; the salt water forms the lower stratum.
"Where the Amazon, the La Plata, the Orinoco, and
other giant streams pour their vast volumes into the
ocean, the surface of the sea is fresh many miles from the
shore ; but this is only superficial, for below, even in the
bed of the river, the bitterness of salt water is found"
(Hartwig).
Truly, "they that go down to the sea in ships, and
occupy their business in great waters ; these men see the
works of the Lord, and his wonders in the deep."
CHAPTEE XV
MOUNTAINS AND VOLCANOES
" There is silence on the tall mountain peak, with its glittering
mantle of snow, where the panting lungs labour to inhale the thin
bleak air ; where no insect murmurs, and no bird flies, and where the
eye wanders over multitudinous hill-tops that lie far beneath, and
vast dark forests that sweep on to the distant horizon, and along
deep valleys where the great rivers begin." HUGH MILLER.
THE reader will probably wonder what mountains and
rocks have to do with water : we will try, without tres-
passing unduly on the domain of geology, to trace briefly
its work in this connection.
" There was a period," says Kuskin, " or a succession of
periods, during which the rocks which are now hard were
soft, and in which, out of entirely different positions, and
under entirely different conditions from any now existing
or describable, the masses, of which the mountains you
now see are made, were lifted and hardened in the positions
they now occupy."
We may at once dismiss the igneous rocks, or rocks
that were once in a molten condition and have cooled
down, such as lava and the granites ; metamorphic rocks
we will also pass over, as it is doubtful if water had much
to do with their formation ; we must confine ourselves to
stratified or aqueous rocks, which in past ages were
thrown up into mountain masses by mighty subterranean
movements.
344
FORMATION OF MOUNTAINS 345
Formation of Mountains
" The dust we tread upon was once alive." BYRON.
Many rocks and mountain ranges were formed mainly
by the action of water in the first instance, and, as all
mountains are being destroyed by water, slowly but surely,
we are bound, in this story of water and its work, to devote
some little time to them.
The building of mountains is even now going on : the
stratified rocks owe their very existence to water. They
contain, in a fossil state, the remains of animal and vege-
table life, principally the remains of marine life, and were
once sediment deposited at the bottom of the seas and
lakes.
Shells, fish, weeds, corals, etc., became embedded in the
sediment, and by process of time became the fossils we
now find. The word fossil is derived from the Latin fossus,
"dug up."
It is almost beyond our power to conceive how many of
the mighty mountains came to be composed of organic
remains, from base to summit. It is but the work of
ages; layer after layer of sediment or mud, containing
living creatures, was deposited by water, followed by
upheaval; for the sea has not been lowered that could
not be.
" The Maker ! ample in His bounty, spread
The various strata of earth's genial bed."
BROOKE.
Fossil shells which were once crawling on the bottom of
the seas, lakes, and rivers, and of forms such as now
abound in the same, are met with, far inland, both on the
surface, at great depths below it, and at great heights above
sea-level: in the Pyrenees at an elevation of 8000 feet,
10,000 feet in the Alps, 13,000 feet in the Andes, 14,000
346 WATER : ITS ORIGIN AND USE
feet in the Peuquenes ridge, on the Chilian side of the
Cordillera, and 18,000 feet in the Himalayas.
This action is now going on. In the making of rocks
no new matter is necessary : it is but the rearrangement
of the material in existence.
What is deposited in one place is but the outcome of
disintegration and denudation of other parts.
The slates which form the roofs of our houses provide
a familiar instance of a water-formed rock, being but
precipitated or deposited mud, turned first into clay, and
compressed into rock by varying geological conditions.
The chalk hills are but the accumulation of the shells of
myriads of small creatures.
" The endless kind of creatures which by name
Thou canst not count, much less their natures aim."
SPENSER.
But we will deal more fully with chalk in the next
chapter.
" The earth is never at rest ; it has had, and is undergo-
ing, endless vicissitudes ; even the matter that is seem-
ingly unchangeable, is in reality in a state of ceaseless
transformation. The mould of our garden is but the result
of the disintegration of the apparently solid and stately
rocks ; even the stately Andes are wearing away, and every
river which flows to the sea alters the configuration of the
country, and does its little to lay the foundation of new
lands, miles away" (Robert Brown).
The great mountain ranges were no doubt due to direct
upward pressure from below, caused by the pressure of the
earth's crust contracting as it cooled. Notwithstanding
their enormous heights at the present time, Professor
Ramsay proves that 29,000 feet have been removed from
the Welsh mountains (Snowdon, now 3571 feet high, is but
the stump of what was once a colossal eminence), and that
MONTE ROSA.
Mrs Aubrey Le Blond.
[To face p. 346.
FORMATION OF MOUNTAINS 347
in Switzerland an amount equal to their present height
has been removed from the mountains.
This must not be taken to mean that they were double
their present height, as elevation and erosion must have
gone on contemporaneously.
Our Welsh hills are far more ancient than their
larger brethren. They had been mountains for ages
and ages before the materials which now compose the
Kigi or Pilatus were deposited at the bottom of the
sea.
The Welsh mountains are older than the Vosges, the
Vosges than the Pyrenees, the Pyrenees than the Alps,
the Alps than the Andes, which last indeed are still
rising.
"The Cambrian period was an epoch of vigorous
volcanic action. The products of the volcanoes are seen
in the Skiddaw slates of the Lake District, where about
12,000 feet of volcanic ash and Andesite lava, of Honister
Crag and Seathwaite, mark the beginning of volcanic
action which continued through the accumulation of the
Borrowdale series of rocks " (Brend).
" Who can avoid wondering," writes Darwin, " at the force
which has upheaved mountains, and even more so at the
countless ages which it must have required to remove
and level whole masses of them ? "
As soon as a mountain range is raised, all nature
conspires against it : sun, frost, heat, cold, air, water, ice,
and snow ; all plants, from lichen to oak ; every animal,
from worm to man.
Water, however, is the most powerful of all the agents
of disintegration ; autumn rain saturates every pore and
cranny, and frost cracks and splits the hardest of rocks ;
spring comes, sun melts the snow, swelling the rivers,
which carry off the debris to the plains.
348 WATER : ITS ORIGIN AND USE
Altitude of Mountains
" In bluish white the farthest mounts arise,
Steal from the eye, and melt into the skies."
HAKTE.
By comparing Snowdon which many of us have ascended
with some of the monsters of other countries, we shall
get a more accurate idea of their immensity.
These heights, enormous as they are, are only in propor-
tion to the enormous rivers to which they give birth, and
the continents in which they are found.
Nature verily seems to work to a scale, and to maintain
a uniformity in these mighty works as well as in the
minutest form of creation.
Height in feet.
Snowdon, Cambrian system '*1 ' . 3,571
Ben Nevis, Inverness in*- ; ;*i;T- .4* 4,400
Hermon, Syria . . l( j, 3.", a : . >. 10,000
Maindetta, Pyrenees . - f . 11,500
Cook, New Zealand . . ';"' . 12,000
Columbia, Rocky Mountains . . 14,000
Ras Dashan, Africa . . **V'fl . 15,100
Mont Blanc, Alps . i "*i ><vi '< . 15,732
Ararat, Armenia rff . .... -,,- . 17,000
Elburz, Caucasus . .. ( [ . ^ t . '18,500
Demavena, Persia . . . . . 19,400
Logan, Calif ornian range . , F ' J . 19,500
Kilimanjaro, Africa .... 19,600
Chimborazo, Ecuador, Andes . i, 20,703
Aconcagua, Chilian Andes . i} #. . . 23,910
Sorata, Andes . . . . ?f ,, . 24,600
Everest, Himalaya . .. ' . . 29,002
Influence of Mountains on Rain
The cold crests of mountains aid in the work of conden-
sation ; hence the enormous rainfall in mountain districts.
It is found that the amount of rain collected increases
Mrs Aubrey Le Blond.
A MOUNTAIN SUMMIT, PIZ BERNINA.
Mrs Aubrey Le Blmid.
A HANGING GLACIER ON OBER GABELQORN.
[To face p. 348.
VOLCANIC MOUNTAINS 349
with the altitude, but only up to a moderate elevation;
after which there is a reduction, due to the fact that the
air is too cold to contain much vapour, and the amount
of rain decreases accordingly. This height of maximum
fall varies with the locality. At Cherra Punji, in the
Khasia Hills, Assam, to which we have previously referred,
the enormous annual rainfall recorded takes place at an
altitude of about 4000 feet only.
Lofty mountain ranges also greatly influence the dis-
tribution of heat and moisture. The west winds from the
Pacific, on reaching the coast ranges of California, are
turned southwards and thus become north winds.
We have only to refer to the figures given under Rain
and note the effect of our comparatively small mountains
on the rainfall. From these we shall be able to form
some idea of the influence of the mighty mountain ranges
on the rainfall of any country, which yields a copious
supply of water to the lakes nestling in the valleys below.
The deserts in Central Australia and Arabia are prin-
cipally due to the absence of mountains, and the distance
from the sea.
The Desert of Gobi, and many similar rainless regions,
owe their aridity to the fact that they are shut off from
the influence of moist winds by high chains of mountains,
which arrest the clouds, and by condensation almost
entirely exhaust them.
Volcanic Mountains
The building up of mountains by volcanic action is still
going on. Many of them are but extinct volcanoes, and
as the influence of mountains on atmospheric precipitation
is great, they claim a place in our story.
It is assumed that, notwithstanding the enormous
350 WATER : ITS ORIGIN AND USE
amount of denudation that is continually in progress,
the total area of land above sea-level remains uncli-
minished. "Running water," says Lyell, "and volcanic
action are two antagonistic forces: one labouring con-
tinually to reduce the level of the land to the sea, the
other to restore and maintain the inequalities of the
crust, on which the very existence of islands and
continents depends."
Ruskin says : " Having invented telescopes and photo-
graphy, you are all stuck up on your hobby-horses, because
you know how big the moon is, and can get pictures of the
volcanoes on it ! But you never can get any more than
pictures of these, while in your own planet there are a
thousand volcanoes which you may jump into if you have
the mind to, and may one day perhaps be blown up sky-
high by, whether you have the mind or not."
Von Humboldt gives the number of volcanoes as 323,
but according to Keith Johnston 300 are recorded, some
always active, but some only occasionally. Some of these
are probably now extinct. On the eastern slope of Mount
Loa (Mauna Loa), in Hawaii, which is 14,000 feet high, is
the crater of Kilauea, which opens at 4400 feet above the
sea. It is the largest active crater in the world, and has
a diameter of over 2 miles and a circumference of about 9
miles ; it is oval in shape, with vertical sides 1000 feet
deep, and the bottom is covered with red boiling lava ; the
heat and light given out by this vast lake are intense.
Most of the mountains of Iceland have been volcanoes ;
at least twenty-five of them have been active within the
last 1000 years. In 1766 Hecla threw out a column of
ashes 16,000 feet into the air.
What mind can grasp the magnitude of the extinct
volcano Askja, in the centre of Iceland, 4000 to 5000 feet
high, its crater being 17 miles in circumference ?
VOLCANIC MOUNTAINS 351
The famous Popocatepetl, or "smoking mountain," of
Mexico, is an interesting study. It rises in the form of a
snow-covered, regular cone to a height of 17,853 feet ; the
pine forests cease at 12,544, and the snow-line is 14,960.
On the summit is an enormous crater 5000 feet in diameter,
with a sheer depth of 2000 feet, which forms a cauldron
of sulphur, which is worked by the Indians.
Fujisan, over 12,000 feet, crater 500 feet deep, is now
apparently extinct : the last eruption took place in 1707.
Volcanic eruptions frequently occur under glaciers. On
llth May 1721, during the eruption of Katla (Iceland), an
enormous mass of glacier ice was carried from its position,
covering the sea to a distance of 3 miles from the coast,
and the Myrdalssandur was flooded to a depth of 300 feet.
By the well-known eruption of Eotomahana, in New
Zealand (to which reference has already been made), the
whole surrounding country was covered in places to a
depth of 200 feet by mud and scoriae, over which nature,
as if to cover her work of desolation, has caused the Scotch
thistle, ferns, and other vegetation to grow and form a
covering.
Many of these extinct volcanoes, that once belched forth
fire, now stand peacefully capped with snow, and call to
mind the lines
" But soaring snow-clad through thy native sky,
In the wild pomp of mountain majesty."
Ghilde Harold.
Another example of mountains of this description is
Mount Shasta in California. This mountain can be seen
at a distance of 100 miles. It is 14,400 feet high ; at its
base the circumference is 75 miles ; its crater is a mile in
diameter and 1500 feet deep.
In the Andes we have many enormous volcanic
mountains, both extinct and active. Among the active
352 WATEK : ITS ORIGIN AND USE
ones are Pichincha, 15,918 feet high, with a crater 2500
feet deep ; also
Tunguragua . . 16,685 feet high.
Sangay .... 17,460
Cotopaxi .... 19,550
Tolima . . . .17,660
Gualateiri .... 21,960
The moon's surface is pitted all over with craters of
enormous size, similar to those of the volcanoes on the
earth. Many of them are 50 to 60 miles in diameter,
some over 100 miles; small ones, up to 8 to 10 miles in
diameter, exist by the thousand. They are nearly all
circular, and surrounded by mountains up to about 20,000
feet high. In the centre of the craters is usually seen a
peak or peaks, rising to the same altitude as the surround-
ing mountains. Many craters are filled to the brim, others
are very deep.
Young, in his Astronomy, tells us that these are fossil
formations, the result of true volcanic eruptions ; for no
evidence of existing volcanic activity has ever been found,
all appears to be absolutely quiescent " still as death."
Volcanic Eruptions
M From the volcanoes gross eruptions rise,
And curling sheets of smoke obscure the skies."
GAKTH.
It is a remarkable fact that out of 323 active volcanoes
enumerated by Fuchs, all excepting two or three in
Central Asia, and the same number in America, are near
the ocean.
It is generally accepted that volcanic eruptions are
more or less due to the action of water, which, percolating
through the fissures in the surface, finds its way to the
hot regions beneath, where it is formed into steam at high
VOLCANIC ERUPTIONS 353
pressure, and forces a passage for itself through the crust
of the globe, which is practically floating upon an internal
nucleus of molten elements, and in an eruption these
molten elements burst forth as liquid streams of lava.
The reader will probably wonder what use in the
economy of nature the volcano and its attendant train of
forces have. " The detritus," says Dr Buckland, " of the
first dry lands, being drifted into the sea, and there spread
out into extensive beds of mud and sand and gravel, would
for ever have remained beneath the surface of the water,
had not other forces been subsequently employed to raise
them into dry land ; these forces appear to have been the
same expansive powers of heat and vapour which, having
caused the elevation of the first-raised portions of the
fundamental crystalline rocks, continued their energies
through all succeeding geological epochs, and still exert
them in producing the phenomena of active volcanoes,
phenomena incomparably the most violent that now appear
upon the surface of our planet.
" We therefore see that volcanic action is the principal
force at work in the elevation of land from the ocean bed.
" Volcanic eruptions, therefore, are not only a means of
destruction, but of reconstruction and renovation.
"The order that now reigns has resulted from causes
which have generally been considered as capable only of
defacing and devastating the earth's surface, but which we
thus find strong grounds for suspecting were, in the
primeval state of the globe, and perhaps are still, instru-
mental in its perpetual renovation.
" The great periods of upheaval, by volcanic and other
disturbances, took place long before the creation of man,
and may be looked upon as a series of mighty evolutions
to fit our globe for life, both animal and vegetable."
Many theories are advanced as to the cause of volcanic
1 23
354 WATER : ITS ORIGIN AND USE
eruptions, but all fail more or less to solve the problem to
the satisfaction of those competent to judge of their
accuracy.
Professor Milne finds some connection between this
phenomenon and the periodic shifting of the earth's axis.
Professor Doelter attributes it to the variation of
melting point with pressure.
" The lava of Vesuvius melts at a temperature of 1900 F.
under ordinary atmospheric pressure, but the temperature
at which fusion takes place is increased about one-
twentieth of a degree for each atmosphere. This is
not continuous ; for the rise of melting point gradually
reaches a maximum, after which any further increase of
pressure leads to a lowering of the melting point.
" There must, therefore, be a level below which all rocks
are in a state of fusion.
" Taking the mean rate of increase of 1 F. for each 60
feet, the underground temperature would overtake the
rising melting point at, say, 70 miles, while the maximum
melting point would not be reached under a depth of 100
to 200 miles.
" These conditions, combined with water and gases, given
off as solidification ensues, or, as some assert, which have
gained access by percolation and capillary attraction,
cause an increase of pressure which, becoming great
enough to overcome the resistance, leads to an eruption,
and the molten magma of the earth's interior is belched
forth."
It is concluded that the source of activity of Vesuvius is
at a depth of about 12| miles, and the temperature at that
depth would be about 2550 F.
As this volcano has recently been in a state of
eruption, the following particulars from the Daily Tele-
graph of 10th April 1906 may be of interest :
VOLCANIC ERUPTIONS 355
" Vesuvius is a comparatively recent mountain raised in
Tertiary times. For several centuries the Romans
regarded it as a force which was spent. In the second
Servile war Spartacus and his followers encamped within
the crater. The first eruption of which we have any
record took place in A.D. 63, when Pompeii suffered
seriously. Its citizens were still rebuilding or repairing
their shattered homes when they were overwhelmed by
the great eruption of A.D. 79, which blotted out the city.
Including the inhabitants of Pompeii and Herculaneum,
200,000 persons are supposed to have perished. Then
ensued another era of repose.
" It was six centuries later before another serious erup-
tion occurred, that of 1631, in which, it is reported, 18,000
persons perished. Thereafter the intervals grew shorter,
and since 1701 the great volcano has been chronically
perturbed. In the eighteenth century twenty-six con-
siderable outbursts were recorded ; and in the nineteenth
century twenty-seven. The most disastrous of these
occurred in 1767, 1794, 1822, 1867-8. The latest note-
worthy displays were in 1872, 1879, 1885, 1892, 1897,
1900-1."
During the eruption of Imbaburu, Ecuador, in 1691,
floods of mud were emitted in which were an immense
number of dead fish, the stench of which caused a
pestilence in Huera. This points to the breaking in of
the sea, and its coming into contact with the internal heat.
The steam ejected by one of the parasitic cones of Etna,
during an eruption of 100 days, is estimated to have been
equal to 460,000,000 gallons of water.
In the year 1883 Krakatoa poured forth a vast volume
of steam which escaped from an opening 30 yards wide.
This was followed by the greatest volcanic eruption ever
known : the atmospheric vibrations encircled the globe,
356 WATER : ITS ORIGIN AND USE
and the dust from this eruption was suspended in the air
for about two years, causing beautiful sunsets all over the
world.
Lord Byron, in The Corsair, gives us a beautiful descrip-
tion of a glorious sunset :
" Slow sinks, more lovely ere his race be run,
Along Morea's hills the setting sun :
Not as in Northern climes, obscurely bright,
But one unclouded blaze of living light !
O'er the hushed deep the yellow beam he throws,
Gilds the green wave, that trembles as it glows."
These eruptions give us an idea of the power of the
elements when they break their bounds and fire and water
meet.
The volcano Antuco, in Chili, sent stones flying 36 miles.
Cotopaxi is said to have hurled a 200-ton block of stone
9 miles.
The heat of a volcano is intense. The lava emitted from
Vesuvius melted copper wire when thrust into it. This
requires a heat of 2000 F., which is the fusing point of
copper.
Mauna Loa, an active volcano, already mentioned, has a
terminal crater 8000 feet in diameter, with nearly vertical
walls, inside, 600 feet high. In 1843 there issued from
this three streams of lava 5 or 6 miles wide, 20 to 30
miles long ; in 1859 a stream, which continued to flow for
two months, was 50 miles long, 1 to 5 miles wide, from
10 to hundreds of feet thick, reaching the sea-coast in
eight days ; again, in 1885, there was a flow of 70 miles
long, 7 miles wide.
The lava stream ejected from Skaptar-Jokul, in Iceland,
in 1783, was 50 miles long, with a depth of 500 feet.
Tomboro, a volcano on the Island of Surnbara, in 1851
cost more lives than fell in Waterloo ; and 30,000 to
40,000 people perished at Krakatoa.
EARTHQUAKES 357
During modern times the greatest eruption was on
Coseguina, where for 25 miles the ground was covered with
16 feet of muddy water, and clouds of dust and ashes
extended 20 to the west.
Volcanic eruptions have been known to influence greatly
the fall of rain. Darwin tells us that almost unprece-
dented rain, which fell in Central America at a time of
year most unusual for it, was entirely due to the eruption
of Coseguina, and suggests that there is some intimate
connection between the atmosphere and subterranean
regions.
In the earlier stages of the earth's history the flows of
lava were such as absolutely to eclipse any modern example.
The Deccan basalts of India, for instance, attain a thickness
of 4000 feet, and cover an area of 200,000 square miles.
Earthquakes
Earthquakes, like volcanic eruptions, are generally sup-
posed to have their centres of disturbance under or near
the sea, and they are attributed to the filtration of water
down to igneous matter.
"A bad earthquake," says Darwin, "at once destroys
our oldest associations. The earth, the very emblem of
solidity, has moved beneath our feet like a thin crust over
a fluid ; one second of time has created in the mind a
strange idea of insecurity, which hours of reflection would
not have produced. "
Sir Archibald Geikie, in the Encyclopaedia Britannica,
says : " We must conceive a vast reservoir of melted rock,
impregnated with superheated steam, and impelled upward
by the elastic force of the vapour. It is the pressure of
the imprisoned vapour and its struggles to get free which
produce the subterranean earthquakes and explosions and
358 WATER : ITS ORIGIN AND USE
outpourings of lava. Mallet took this view. An earth-
quake, he said, is an incomplete attempt to form a volcano.
In Mexico the cone of the burning mountain Jorullo was
thrown up in a single night, on 29th September 1759,
after months of subterranean rumblings ; a small volcano
there doubtless took the place of an earthquake, or a series
of shocks. Mallet supposed that under Montemurro a
cavity in the earth had filled with steam, and that at the
computed depth there would be a temperature of 884 F.,
which would give a pressure of 684 atmospheres, or
10,260 Ibs. per square inch. He reckoned the walls of
this cavity as equal to 27 square miles, and so arrived
at a total pressure of at least 640,258 millions of
tons. The force with which volcanoes like Etna and
Vesuvius can throw up masses of rock 10,000 feet and
20,000 feet, furnishes some indication of their subterranean
energy. But these outbursts are probably feeble com-
pared with the powers that cause such earthquakes as
those of Lima in 1746 ; Lisbon in 1755 ; Calabria in
1783 ; Eiobamba, in Ecuador, in 1797 ; and Peru and
Ecuador in 1868. Professor John Milne says: 'The
Riobamba earthquake, which projected bodies with an
initial velocity of 80 feet per second, appears to have been
the most violent earthquake, so far as impulsive effect is
concerned, of which we have any record. It occurred
among the Andes, where there are volcanoes from 16,000
feet to 21,000 feet high.' The town of Riobamba was
annihilated, and 30,000 persons perished."
On 26th October 1891 an earthquake devastated Central
Japan, causing a loss of 10,000 lives.
Earthquakes are mentioned in Japan as early as 286 B.C.,
when, according to ancient legends, Mount Fuji rose and
the Biwa Lake was formed. The earliest authentic record
is A.D. 416.
VOLCANIC ISLANDS 359
Earthquakes have caused lakes to become dry and land
to be depressed, forming sites for lakes.
They are also prolific in the formation, by upheaval, of
geological " faults," and they have in many ways helped to
make this world a fit place in which to live ; and although
at times awful from the damage they cause, and from the
number of the lives that are sacrificed by their fury, they
are not only forces of destruction.
Volcanic Islands
Submarine volcanoes are no doubt caused by the infil-
tration of sea-water. They are of frequent occurrence,
and many new islands have arisen through volcanic action.
" There be lands also," writes Holland, " that put forth
after another manner, and all at once in some sea ; as if
nature cryed quittance with herself e, and made even, paying,
one for another, by giving againe that in one place which
those chawmes and gaping gulfes took away in another."
Early in July 1831, Graham Island, in the Mediter-
ranean, arose out of the sea. In the following August it
attained a circumference of 3 miles, and a height of 200
feet. In less than three months, the sea again claimed it
and lowered it to sea-level, and shortly afterwards reduced
it to a dangerous shoal. It disappeared in 1864.
In the year 1795, on the coast of Alaska, an island
(Bagosloff) rose out of the sea 42 miles from the land. In
four years it was a cone 3000 feet high, 2 or 3 miles in
circumference ; two years later it was still too hot to
walk on, and has since then again been in a state of
eruption.
On the 19th October 1885 a volcanic island arose
in the Pacific near the island of Tonga ; and it has been
recorded that a year after some of these submarine erup-
360 WATER : ITS ORIGIN AND USE
tions, the sea has been so hot as to melt the pitch off the
hull of a vessel passing the vicinity of the eruption.
In May 1883, when Krakatoa, in the Sunda Straits, was
in eruption, an immense wave swept over the shores of the
neighbouring islands, and two new islands appeared where
the morning before there had been from 30 to 40 fathoms
of water.
On 15th December 1906 a new island suddenly appeared
to the north of the Cheduba Island, on the Arakan coast of
Burma. When visited on 30th December by the officers
of the Marine Survey of India, it was found to be com-
posed of mud and still very warm ; 3 feet below the
surface the temperature was 148 F. This island was a
quarter of a mile long, the main crater being 20 feet above
high water.
CHAPTER XVI
CHALK
" He brought water out of the stony rock, so that it gushed out
like the rivers." Psalm Ixxvii. 17.
CHALK has been selected for fuller description as a typical
example of aqueous rock, and, as such, frequent reference
has of necessity been made to it.
Chalk is the rock which forms the higher part of a
series or group of strata, comprising rocks of various kinds,
and termed the Cretaceous system.
It forms our beautiful Downs, Chiltern Hills, Salisbury
Plain, Beachy Head, and the white cliffs of the English
coast.
" Already British coasts appear to rise,
And chalky cliffs salute their longing eyes."
FALCONER.
Its composition varies, but it has been found to consist
of 96 per cent, carbonate of lime, the remaining 4 per cent,
being silica, clay, etc.
It is estimated that the enormous masses of carbonate
of lime are equal to about one-eighth part of the entire
mass that forms the superficial crust of the globe.
Formation
" Chalk was probably formed by the decomposition of
sea- water ; then, holding lime and silica in solution, the
carbonate of lime and silica fell to the bottom together,
361
362 WATER : ITS ORIGIN AND USE
forming chalk and flints. The silica was especially
attracted by the organic remains lying on or beneath the
beds, and collected around the same, forming the familiar
flint " (Phillips). Frequently fossil sponges, Echinoderms,
and other Cretaceous organisms are completely turned into
flint, as well as being embedded in it.
" In a similar manner the Oolitic matter has collected
around shells, the Lias limestone round ammonites, the
carbonate of iron round ferns, etc." (Phillips).
Flint is found in the Upper Chalk in horizontal layers ;
in the Middle Chalk, however, it is only found in scattered,
irregular-shaped pieces of all sizes ; it is rarely met with
in the Lower Chalk, but I have occasionally had to pierce
hard masses of it in this part of the formation.
It was from this product of the work of water, by which
this hard siliceous stone was formed, that our ancestors
made their first implements of peace and warfare; the
flint axe, with which they hollowed out their rude boats
and of which they made their arrow and lance heads,
knives and wedges, similar to those still used by some of
the savage tribes. Truly, the slaughter of animal and man
with such weapons must have been a gruesome operation.
It was this same rock, pulverised and put through
certain processes, that formed the original material from
which the glass called flint-glass was made. This was
formerly used largely for the object-glasses of telescopes and
microscopes, etc., but it is now more or less supplanted.
The varied uses to which chalk is put in the form of lime,
cement, etc., are too well known to need mention here.
The carbonate of lime is composed almost entirely of
shells. A microscopical examination of a piece of chalk will
show thousands of perfect shells in a cubic inch, and that
it consists largely of parts of bodies of minute animals.
" Every stratum was the burial-ground of its time." LYBLL.
FORMATION 363
" It is surprising," says Dr Buckland, " to consider that
the walls of our houses are sometimes composed of little
else than comminuted shells that were once the domicile
of other animals at the bottom of the ancient seas and
lakes." Vast areas of the bed of the Atlantic Ocean are
said to be covered with calcareous mud, which consists
principally of living Foraminifera, engaged in secreting
lime from the water and forming their shells.
These minute marine animals, which are diffused
abundantly in all but the Polar seas, collect by imbibition
the carbonate of lime, etc., held in solution (not solid
particles in suspension) by the sea-water, building it into
their structures. In this manner they have formed and
are still forming limestone and chalk, which are composed
almost entirely of these little creatures, chiefly of the
genus Globigerina.
Minute animals similar to those forming the chalk hills
of our country are found in the " Levant mud," the white,
chalk-like deposit on the bottom of shallow seas. This
mud, when dried, corresponds in every particular with
the chalk.
Over a large portion of the Atlantic basin is an abund-
ance of minute Foraminifera, the accumulation of whose
shells and disintegrated remains forms a calcareous deposit
of unknown thickness, which also corresponds in all
essential particulars with chalk. We have here chalk
beds in the course of construction, and can see nature
carrying on the process of building up rocks.
One writer, referring to these minute and apparently
useless creatures, states :
" For all are equally
A link of nature's chain,
Formed by the hand that formed me,
Which formeth naught in vain."
364 WATER : ITS ORIGIN AND USE
Although we can safely assume that chalk is formed in
this manner, it still remains a mystery from whence the
sea obtained such enormous supplies of this substance as
to have formed and still be forming rocks of this descrip-
tion ; for carbonate of lime, unlike sand, clays, etc., is not
the result of disintegration : " The only remaining hypo-
thesis," says Dr Buckland, " being that lime was continu-
ously introduced into the lakes and seas by water that had
percolated rocks through which calcareous earth was
disseminated."
Thickness of Chalk
The thickness of the chalk in England is seldom less than
500 feet, and rarely so much as 1000 feet. In the Isle of
Wight, however, the section at Culver Cliff gives from
1200 to 1300 feet. It is also about 1200 feet thick in
Dorset and Hampshire.
The maximum thickness of the chalk found in England
is said to be 1700 feet. A deposit of this depth would
require 2,000,000 years for its formation, for it has been
estimated that 1 inch only of chalk is deposited in 100
years.
Flint and Gravel in Chalk
Flint, gravels, and clay are formed by the destruction
of the chalk, thus providing the natural soil of the chalk
districts. This is solely the work of water, and is a very
slow process ; it is estimated that the chalk rocks are worn
away at the same rate at which they are formed, viz.
1 inch in 100 years.
In a similar manner, in districts in which granite or any
other rock forms the surface rock, the soil is formed by
the disintegration of the same. In the granite districts
DISINTEGRATION 365
the apparently indestructible formation is found to have
been subjected to the ravages of chemical action to a depth
of 30 to 40 feet in places.
Disintegration
When we consider these periods of formation and
destruction of chalk rocks only, it requires but little
stretch of the imagination to grasp Lord Avebury's state-
ment : " We can hardly estimate at less than 100,000,000
years the time which must have elapsed since the com-
mencement of life on our planet. Out of this the Tertiary
Period might occupy, say, 5,000,000 years, the Glacial
Period may have commenced about 200,000 years ago, and
lasted down to within about, say, 50,000 years of the
present time."
" How long ago ? " is a question often asked of geologists.
As a rule no answer can be given. A unit of time is still
wanted. Mr E. A. Martin, F.G.S., attempts a general
reply in the Geological Magazine for August 1907. He
observes that Professor Huxley's willingness to confine
himself to 100 million years is not now altogether approved,
since the discovery of the energy lying dormant in radio-
active bodies has shown the possibility of the far greater
age of the sun than the physicists would formerly allow.
" I am justified from many points of view," he writes, " in
assuming that a solid crust had formed about 250 million
years ago, that strata had formed at an average rate of 1
foot in 700 years, and that the older the rocks the more
the strata have been compressed into thinner layers." On
this basis Mr Martin computes that " the Coal Age came
to a close over 70 million years ago, and the Chalk Age
31,680,000 years ago; and that the winged reptiles of
Jurassic times took 21,875,000 years for their evolution."
366 WATER : ITS ORIGIN AND USE
The author gives good reason for these computations, and
there is no more antecedent motive for cutting down time
than limiting space. We should be inclined to think, with
Professor Sollas, that the rate of deposition, 1 foot in
700 years, is on the average too slow (Daily Telegraph).
The chalk escarpment usually forms the highest ground ;
this is the case in the Weald of Kent ; and at Blue Bell
Hill, in the neighbourhood of Chatham, it reaches an alti-
tude of 600 feet.
Chalk as a Natural Filter-Bed
Where rivers obtain their supply direct from the rain-
fall, they only flow in rainy seasons and cease to run in dry
weather.
Where supplied by rain indirectly, as through the inter-
mediate agency of springs fed by Chalk formation, they
continue to flow in dry weather, the undergound sources
supplementing and continuing the direct supply, as the
Chalk formation maintains the summer flow of the Thames.
This formation was tested for this purpose in 1859, when
the river Wandle was found to continue its yield of water
(from the chalk springs) at least eighteen months after it
had practically ceased to receive a supply from the surface,
so great is the amount absorbed by the chalk.
The chalk springs at Chadwell, near Ware, the source
of the New Kiver (opened in 1613), alone yield 4| million
gallons a day.
The Chalk formation is one of the best natural filter-beds
for water; it absorbs a large quantity and yields it up
again in the form of springs, as we have already seen. The
chalk practically forms a reservoir, preserving the water
pure and at an even temperature of about 50 F., cool and
refreshing in summer and far from freezing in winter.
WATER CONTAINED IN CHALK 367
Water contained in Chalk
The specific gravity of chalk is 2'315 ; a cubic foot weighs
145 Ibs. and will hold 2 gallons of water ; a cubic yard
will hold 54 gallons, and 1 acre 1 yard thick will hold
261,360 gallons; a square mile the same thickness holds
167,270,000 gallons. These figures give some idea of the
water contained in the chalk.
All rocks absorb water in proportion to their degree of
porosity.
Per cent, of water
by weight.
Granite will absorb . . . O'l to 0*4
Gypsum ... 0'5 , 1-5
Slate ... 2-0
Sandstone 3'0
Limestone . . . 5'0
Chalk ... 15-0
Plastic clay . 19'0
Marl and loam . 30*0
10-0
8-0
8-0
20-0
24-0
50-0
In the Geographical Journal, 1902, it is stated by W. G.
Cox, C.E., that chalk of the Cretaceous formation of the
London Basin has, by careful research, been found to contain
for each square mile 1 yard thick 3| million gallons of
water. The same quantity of rock is capable of absorbing,
if saturated, 200 million gallons.
In England this formation has a surface area of 3794
square miles, upon which falls as rain 4000 million gallons
daily, a quantity equal to five times the summer flow of
the Thames.
Water experiences little difficulty in obtaining ingress
to chalk but considerable resistance to its egress, as the
capillarity of chalk appears to accelerate the inflow of
water and to impede its discharge.
Professor Boyd Dawkins evaporated 2'542 gallons of
water from a cubic foot of chalk, but on resoaking found
368 WATER : ITS ORIGIN AND USE
it to absorb only 2 '437 gallons, or 95'86 per cent, of that
previously evaporated ; this loss was no doubt due to the
obstructive action of the air in the pores of the chalk.
Eeferring to this subject, Mr Charles Bird, F.G.S., says :
" If a cubic foot of sand will bear the addition of 3 gallons
of water, it is apparent that there is only a little over half
the solid capacity of sand, 6 gallons being equal to 1 cubic
foot. This does not follow that 3 gallons of water could
be obtained as the yield from every foot of sand, or 18
pints for every cubic foot of chalk, for in the latter case
it would retain by imbibition 10 pints, yielding only
8 pints.
" A cubic foot of chalk below the water level will contain
18 pints of water (35 per cent, of its own bulk of water
of saturation) ; above this level it will be found to contain
10 pints to the cubic foot (19 per cent, of its bulk) : this is
called ' water of imbibition, ' or ' quarry water. '
"The force which causes this phenomenon is called
' capillary attraction/ and as moisture is removed from
the top by evaporation fresh supplies rise by ' capillary
attraction ' from the saturated portion below. The inter-
stices of the chalk which are not filled with water making
the difference between 35 per cent, and 19 per cent, above
stated are filled with air, the explanation being that some
of the cavities are too large to retain water by capillary
attraction."
Natural Chambers
A considerable amount of water is stored in the joints
and fissures in the chalk, which are sometimes of enormous
size. The natural adit at the Strood waterworks, the
property of the city of Eochester, is well known to the
writer, and a short description may be of general interest.
By kind permission of the engineer, Mr William Banks,
I fc
NATURAL CHAMBERS 369
I am enabled to reproduce plan, sections, and photographs
of this remarkable adit or natural passage.
As will be seen by the sections, there is a large natural
chamber, over 17 feet high, of considerable width and
length, and from this chamber there is a natural adit,
through which a person can walk for about 60 feet ; after
this it gradually gets smaller, but a considerable distance
further can be seen.
The whole of the water for the supply of Strood, Kent,
flows through this adit and chamber. The adit is a sight
not easily forgotten ; here, at a depth of 120 feet below
the surface, flows a small stream of clear, sparkling water
through enormous cavities not made by hand.
To enable the photographs to be taken, the water was
pumped out. This necessitated long, continuous pumping
to overcome the inflow of the water from the springs, by
which all these adits and the chamber are quickly filled,
as they are almost entirely below the line of saturation.
Professor Prestwich states that in sinking a well in the
chalk near the edge of the escarpment at Knockholt, the
workmen discovered, at a depth of 270 feet, a cave of 30
feet long, 12 feet broad, 18 feet high, of irregular shape, at
the bottom of which ran a stream of water.
Another curious natural opening in the chalk was found
by the writer during the extension of some adits ; this
natural opening was cut completely through.
It was large enough for a man to stand up in, and after
going a few feet, a pipe or branch passage turned sharply
upwards in a spiral form towards the surface ; the end was
hidden from view, but a distance of over 30 feet upward
could be seen, as shown in the section.
This, like many similar spaces in the chalk, appeared to
have been at one time partly filled with a brown, soapy,
laminated clay.
24
370 WATER : ITS ORIGIN AND USE
Some authorities are of opinion that the soapy clay so
often found in these seanis and adits is now being deposited
by water which percolates through them and fills up the
various cavities, but it is more probable that these deposits
were formed long since, for the seams cut in the upper
chalk above the line of saturation, where there is no
running (or free) water, are also frequently found full of
the same material.
This cavity or fissure, like many others, was yielding
but a small supply of water at D, out of all proportion to
the size of the opening, but no water was running down
the vertical adit C C.
These large natural watercourses are a part of nature's
system of drainage, and under prehistoric conditions,
when the rain and melting of the ice (which helped to
form these dry valleys) were at the most active period of
operation, they carried off the water in greater quantities
than we can well imagine, delivering it, probably as sub-
marine springs, into the rivers and sea.
Water-worn fissures, now dry, are frequently seen high
above the present rest-level of the water, proving that the
variable line of saturation was much higher in remote
ages than to-day.
Another interesting cavity was found by the writer in
sinking a deep boring. At the commencement of the lower
chalk, 250 feet from the surface, the boring tool met with
practically no resistance through 40 feet of descent. No
debris was brought to the surface during that distance ;
what little was cut at places disappeared down a fissure.
Some time was spent in ascertaining whether there was
water in this cavity. A little ingenuity was necessary here,
for the boring commenced from the bottom of a well 150
feet deep, containing about 80 feet of water. This upper
water was kept from entering the boring by means of
THE NATURAL CHAMBER, STROOD WATERWORKS, KENT.
Muskett and Sills.
THE NATURAL ADIT, STROOD WATERWORKS, KENT.
[To face p. 370.
PERCOLATION IN THE CHALK 371
tubes driven through the bottom of the well. A tubular
pump was lowered into the boring and set to work, and
the fissure, 100 feet below an immense body of water, was
tested, and there was found to be no yield.
The Lower Chalk rarely yields any quantity of water,
the most favourable conditions for water being where the
Upper Chalk is below the line of saturation ; here a con-
siderable quantity may generally be obtained if there is
a corresponding watershed behind it.
Percolation in the Chalk
" The salts with curious percolation strain,
And kindly through the porous strata drain."
BROOKE.
From a report of the Royal Commission when the Dover
and St Margaret's area was tested, a drainage basin of 12
square miles yielded 5| to 6 million gallons per day. On
a basis of 5 millions we get 10 inches of percolation on the
square mile of chalk ; at Croydon 11 inches were found to
percolate. Other trials have shown that 10 '6 out of a
rainfall of 25 to 27 inches find their way through the
chalk.
The Royal Commission (Balfour) on London water
supply reported that not more than 3| inches of percola-
tion in the chalk north and south of London could be
relied on.
The average rainfall for the Chatham district is about
26 inches. Allowing, say, 8 inches for the annual percola-
tion, the difference, 18 inches, would represent the loss by
evaporation and absorption by vegetation.
Adits in the Chalk
We have seen what enormous quantities of water are
held in the pores of the chalk, but it is not wise to rely
372 WATER : ITS ORIGIN AND USE
on all this quantity as being available for consumption,
for it will yield only 8 parts and retain 10 parts, as we
have seen ; but rather the free water in the seams, joints,
and cavities, that has percolated from the surface and is
passing on to its original outlet resembling an underground
stream similar to the natural chambers and adits already
described.
The writer has frequently found, after driving a large
adit many hundreds of feet into the chalk at a depth of
about 100 feet below the rest-level, that the chalk does
not yield even a trickle of water. When approaching
within a distance of, say, 4 or 5 feet of a large spring, the
only indication would be a kind of sweating. Beads of
water would be seen, hardly sufficient to trickle down the
sides of the adit ; a few feet further, and a blow with a
pick would necessitate a quick withdrawal for safety.
This proves how tenaciously the saturated chalk clings to
the water it absorbs. It does, of course, contain 2 gallons
per cubic foot, and it holds very tightly to it.
Description of Adits
It is only at certain periods, when works are being
carried out during the course of which it is necessary to
keep down the water by pumping, that it is possible to
visit these underground reservoirs, both natural and
artificial. There is always a certain amount of risk in
penetrating the water-bearing strata, and permission to
do so is not readily granted.
Familiarity breeds contempt, and one who has spent
many hours daily in these subterranean passages forgets
about risk, and takes it as a matter of course.
It is a fascinating experience. On reaching the bottom
of the well, say, 250 feet deep, you alight on a stage: the
water is rushing under your feet on its way to the pumps.
AN ARTIFICIAL ADIT IX THE CHALK FORMATION, WITH BRANCHES RUNNING
IN ALL DIRECTIONS TO INTERCEPT THE WATER-BEARING FISSURES.
[To face p. 372.
DESCRIPTION OF ADITS 373
Artificial adits are usually at least 9 to 10 feet high and
nearly as wide, cut in the pure white chalk, and for
scientific reasons they are generally parabolic in section.
Branching out in all directions are other passages and
crevices, down which the separate streams from the various
springs are conducted to the pumps. You will have been
provided with Sou'wester, oil-skins, and top-boots, and
are standing perhaps 100 feet below the level to which
the water will rise when the pumps stop. You will then
wade perhaps 1800 or 2000 feet up one of these passages,
through 18 inches of pure bright water, by the light of
lamps or dozens of candles fixed on the sides of the adit
to illuminate it. At last you come to a spring, spurting
out of the chalk in front, overhead, and on either hand,
also bubbling up under your feet, as may be seen in the
picture.
This spurting and bubbling is at once suggestive of
great force: at times it will bowl along large pieces of
chalk, or easily knock down a man. The reason is not far
to seek. We have already stated that you are now
standing 100 feet below the rest-level of the water, which
means that all around you the rock is charged with water
to a height of 100 feet ; and the water is rushing to the
point at which you stand, naturally escaping at its lowest
vent. A pressure of 43 Ibs. per square inch would be
required to hold back the water (100 feet x '43 Ibs.).
Here you see, beneath the parched surface of a dry
chalk valley, cool, sparkling waters welling forth :
" How without guile thy bosom, all transparent
As the pure crystal, lets the curious eye
Thy secrets scan."
LONGFELLOW (from the Spanish).
On retracing your steps you may find that the water
will overflow the tops of your boots. To reach the
374 WATER : ITS ORIGIN AND USE
surface again you either use a seat like a swing, called a
boatswain's chair, or, standing with others round the rim
of a large bucket, you are hauled up by a windlass, and you
go home without hose, unless you have provided a spare
pair for such emergencies, thinking of bounteous nature
and her wonders, how you have been deep into her bosom
and have seen the manner in which she provides water for
our use, as is so beautifully expressed by the Psalmist
in the words quoted at the head of this chapter.
By permission of Mr William Ranks, O.K.
AT THE BOTTOM OF THE WELL.
(The bucket ascending with the excavated chalk.)
[To face p. 374.
DENUDATION
The Forces at Work
" There was a period when the mountains we now see were hewn
or worn by forces for the most part differing both in mode and
violence from any now in operation." RUSKIN.
DENUDATION, or the wearing and washing away of the
surface of the earth by the elements, began as soon as land
appeared above the surface of the water, and this work of
destruction and reconstruction has never ceased.
This is the greatest of the works performed by water,
and its name, which means " to strip, or make naked," is
most appropriate, for the action continually exposes the
hard surface of the rocks, that they may be riven asunder
by cold and heat.
The principal forces which carry on this operation are
water, change of temperature, chemical action, and growth
of vegetation ; but water is the principal agent.
Subaerial denudation is the destruction, or, more cor-
rectly, the disintegration, of the rocks by the forces of the
atmosphere sun (heat), ice (cold), wind, rain, lightning,
and all mechanical and chemical forces above the surface
of the sea.
Marine denudation is the work of waves and tides, and
submarine denudation the work of the sea and ocean
currents, at depths beyond our immediate observation,
375
376 WATER : ITS ORIGIN AND USE
but nevertheless work in direct proportion to their own
immensity.
No doubt in ages gone by the whole of the forces
referred to acted with far greater violence than at present ;
the heat, torrential rains, deluges of heated waters, and, in
a later epoch, intense cold, added their powers to the
denudation, thus assisting to destroy the surface of the
earth.
Mr Croll concludes that the whole terrestrial surface is
lowered one foot in 6000 years by subaerial denudation.
The tops of the mightiest mountains have by these
means travelled downward, fertilising the plains and
ministering to the wants of the animal and vegetable
kingdoms ; but their ultimate destination is the great ocean,
where again, after ages of repose, they accumulate and form
massive beds, and will be raised once more above the
waters, and repeat the cycle of changes.
" Here then," says Sir Archibald Geikie, " is a vast system
of circulation ceaselessly renewed. And in that system
there is not a drop of water which is not busy with its
allotted task of changing the face of the earth. When the
vapour ascends into the air, it is almost chemically pure.
But when, after being condensed into visible form and
working its way over or under the land, it once more
enters the sea, it is no longer pure, but more or less
loaded with material taken by it out of the air, or from
rocks or soils through which it has travelled. Day
by day the process is advancing. So far as we can tell,
it has never ceased since the first shower fell upon the
earth. We may well believe, therefore, that it must
have worked marvels upon the surface of our planet in
past time, and that it may effect a vast transformation in
the future."
SUBAERIAL DENUDATION 377
Denudation by Change of Temperature
We have seen that the direct rays of the sun raise the
temperature of the earth about four times as much as
that of the water, the effect being to heat the surface
of rocks by day. causing expansion, as the temperature
falls quickly by radiation at night. This infinitesimal
expansion and contraction, however, splits and disintegrates
the rock, giving freer access to the rain, which accelerates
the work of destruction, to which we shall refer on a later
page.
The wind in a similar degree also assists this work, for
it is found that the amount of sand in the great deserts is
increasing ; clouds of sharp, hard grit or dust, carried by
the wind, beat against the exposed surfaces of the rocks,
and cut into them.
It is stated that in Kerguelen Island, situated in the
Koaring Forties the stormy belt of the ocean between
40 and 50 S., where strong west winds prevail all the
year round all the exposed rocks are grooved in this
manner from west to east.
Denudation by the Atmosphere
The amount of destruction wrought by the chemical
action of the acids contained both in the atmosphere and
rain on rock surfaces is enormous, producing changes
known as weathering.
Here again water and vapour show their handiwork.
The gases in the atmosphere, that is, the oxygen and the
carbonic acid, are continually attacking the rocks, so
affecting the exposed surface as to render it capable of
being acted upon by the rain and its co-partner in the
work of denudation, that is, frost.
Keferring to this weathering of the rocks, Tyndall writes :
378 WATEK : ITS ORIGIN AND USE
" Detached spears and pillars of rock stood like a kind of
defaced statuary along the ridge."
Denudation by the atmosphere is not so apparent ; the
process is slow, but nevertheless sure.
The great Sahara Desert, 3 million square miles in
area, is not, as is generally supposed, a great level desert
and the dried-up bed of a former inland sea; on the
contrary, its configuration disproves that theory.
Its surface level ranges from sea-level to 8000 feet above
it, and it is but the result of the disintegration of the
Sandstone formation by atmospheric influence. In like
manner the principal agents of destruction of the large
stone buildings, cathedrals, etc., in our great cities are the
rain and the atmosphere, and the gases contained in them.
Professor Phillips refers to the subject as follows : " The
wasting effects of the atmosphere are those initial or
preparatory processes by which the earthy materials are
provided for rivers and the sea to transport and deposit
in new situations. The crumbled granite of Muncaster
Fell, Cumberland, is surrounded by heaps of its disinte-
grated ingredients."
In many parts of the earth portions of sculptures broken
from old ruins and buried in the ground are in good pre-
servation, but all traces of workmanship have been obliter-
ated from such parts as have remained exposed to the air.
Denudation by Rain
So slowly does the work of destruction by frost and rain
proceed, that in the short span of a life but little effect is
noticed on the rocks under observation. It is, nevertheless,
an undoubted fact that this work never ceases. Ruskin
says : " The forms of rocks in this manner are so softly
modified that eyes can scarcely trace, or memory measure,
the work of time."
Mrs Aubrey Le Blond.
A GENDARME, NEAR THE ORTLER.
To illustrate the action of the atmosphere on rocks.
[To face p. 378.
DENUDATION BY KAIN 379
The manner in which rain becomes charged with car-
bonic acid has already been explained, as has also the
manner in which it absorbs and holds in solution, by a
chemical process, certain matter with which it comes into
contact ; little remains to be said on this point.
" The chemical properties of water," says Dr Mill, " and
its effects as a solvent, are brought into action by sun-heat,
which separates it from the salts of the sea, shakes it with
the gases of the atmosphere, and pours this powerfully
solvent and oxidising solution over the rocks."
Presuming that one-third of the rain which falls on the
land is evaporated, the remaining two-thirds, whether they
flow into rivers or sink into the earth, are at nature's dis-
posal for use in the work of denudation either chemically
or mechanically or both.
It has been stated that the acid-laden rain of the town
will remove one-third of an inch from the surface of a
marble monument in a century. This seems of little
importance, but with nature's work a century is but a
span long.
This reference to monuments calls to mind a carved
figure which the writer has periodically watched for some
six years. The stone saint stands on an elaborate
truss, formed on one side of a church door ; there is a
stone canopy over the head, so carved that channels cut in
it conduct the few drops of rain that fall on to it directly
on to the nose of the figure. This nose is now all but a
thing of the past, which shows that designers of churches
should give their saints larger canopies or shorter noses.
The following quaint lines also refer to the rapid
destruction of carvings in stone by rain :
" Or find some figures, half obliterate,
In rain-beat marble, near to the church gate."
BISHOP HALL.
380 WATER : ITS ORIGIN AND USE
The carbonic acid in the air is derived from the decay
of organic matter, the breathing of animals, the combustion
of coal, and many other sources. It is partly taken up
by the rain in falling, as well as any other soluble con-
stituents of the air. In its passage through the soil it
accumulates a still further quantity, and is thus enabled
to bring about the changes which we shall describe,
changes which could not be effected by water free from
carbonic acid.
The apparently indestructible granite and harder
crystalline rocks are not proof against this action of
rain ; no known rock can entirely withstand the chemical
action of the carbonic, sulphurous, and other acids in
the air.
Under the action of rain and air the chalk hills are
slowly being dissolved away, the soil and flints that cover
the surface being the undissolved parts which remain.
These form about 4 per cent, of the rock, the remaining 96
per cent, being pure carbonate of lime, which is readily
dissolved by the rain.
In many quarries in Cornwall the rock has been found
to be disintegrated to a depth of 30 to 40 feet, in China
even to 200 feet. This is due to the felspar, the alkaline
salts of soda and potash being decomposed by the carbonic
acid, leaving the silicate of alumina, the mica, and the
quartz.
Thus we see all underground water springs, thermal
waters, geysers, mineral springs is aiding the work of
denudation. Vegetation also assists disintegration : the
roots of plants insinuate themselves into the crevices, grow
and expand, and so help to break up the rocks ; one often
sees rocks and strong walls cracked, lifted, and ever
thrown down by the roots of trees.
SECTION OF THE WEALD OF KENT.
A, Chalk. B, Gault and Upper Greensand. C, Lower Greensand.
D, Weald clay. E, Hastings beds.
C. Spencelayh,
OLD WELL-HEAD, SNODHURST FARM, KENT.
(To face p. 380.
DENUDATION BY RIVERS AND STREAMS 381
Denudation by Rivers and Streams
We have seen how the rivers carry the disintegrated
matter into the lakes and seas, also the amount of solid
matter contained in the water of the various rivers.
" As we watch some tiny rivulet, swelling into a little
brook, joined by others from time to time, grow into a
larger and larger torrent, then to a stream, finally into a
great river, it is impossible to resist the conclusion, gradu-
ally forced upon us, that, incredible as it must at first
sight appear, even the great river valleys and plains, and
the general configuration of the land, though their origin
may be due to the initial form of the surface, are due
mainly to the action of rain and rivers " (Lord Avebury).
The transporting power of water depends on its velocity,
and it increases as the sixth power of that velocity ; or, if
the velocity be doubled, the motive power becomes 64
times as great ; if trebled, 729 times.
The Ganges transports in the four rainy months, to a
distance of 500 miles from its mouth, 577 cubic feet of
solid matter per second. Its annual discharge is computed
at 6,368,000,000 cubic feet, which is equal to raising the
whole of the surface of Ireland 1 foot in 144 years.
Looking nearer home, we find an interesting example of
denudation and transportation.
The Weald of Kent
In the Weald of Kent, between the North and South
Downs, the whole of the Upper Cretaceous formation has
been removed. The Geological section shows the four
principal divisions, Chalk, Greensand, Weald clay, and
Hastings beds. The axis of elevation runs from Win-
chester by Petersfield, Horsham, and Winchelsea to
382 WATER : ITS ORIGIN AND USE
Boulogne. On each side of this axis are two ridges or
escarpments of Chalk and Greensand.
At one time the greensand and chalk formed one
mighty dome across the Weald, joining together the North
and South Downs. In the centre of this district, say at
Crow borough Beacon, where the Hastings beds appear on
the surface, some 2500 feet must have been removed by
denudation.
Here again, as with mountain ranges, it does not of
necessity mean that the altitude of this mighty dome of
chalk was 2500 feet above the present level, as denuda-
tion and elevation no doubt proceeded together.
It is certain, however, that this 2500 feet of the Upper
Cretaceous formation has been removed by the action of
the elements and transported to sea by the rivers.
Thus the rivers chemically and mechanically destroy,
wear away, and transport to the sea the aqueous rocks
which, as the name implies, owe their origin in the first
instance to water, and are constantly re-forming stratified
deposits.
The word " chemically " here refers to the matter carried
away by solution, that is, dissolved. As a typical instance
of this we have the water of the glacier-fed Rhone, which
in January contains 33 parts of dissolved matter per
100,000, diminishing to 10 parts in July and August ; in
this manner 750,000 tons of dissolved matter are carried
into the Lake of Geneva every year by the Rhone, and
400,000 tons by other streams. This will enable us to
form some vague idea of the amount of erosion by solution.
The word '* mechanically " signifies the carrying away
and depositing elsewhere of the solid matter held in
suspension.
The delta of the Po has increased in the last six cen-
turies by 198 square miles, adding that area to Italy, or a
A MOUNTAIN STREAM.
THE ENGLISH CHANNEL 383
gain of ^Q of its previous area. This is a typical instance
of the work water is doing in building up new lands.
These deposits will again be solidified into rock in the
ages to come, and will again be raised above the surface of
the waters, forming new lands, which will in their turn
suffer destruction.
"This let me further add, that nature knows
No stedfast station, but or ebbs or flows ;
Ever in motion, she destroys her old,
And casts new figures in another mould."
DRYDEN.
When we consider that flints form only a fractional
proportion of the whole of the Chalk formation, and note
the immense beds of flint, gravel, and shingle in the
Thames valley, along our south coast, and elsewhere, we
can get a faint idea of the enormous amount of chalk that
has been removed.
The flint was formed in the upper bed of the Chalk for-
mation, in which it occurs as a series of concretions, the
silica in sponges and other marine animals which lived on
the sea-floor while the chalk was being deposited, being
attracted into nodules.
" The calcareous and siliceous dun," says Lyell, " of
which whole hills are composed, has not only been once
alive, but almost every particle albeit invisible to the
naked eye still retains the organic structure which, at
periods of time incalculably remote, was impressed upon it
by the powers of life."
The English Channel
The commencement of a second dome of chalk occupies
the southern half of the Isle of Wight, and rises so
abruptly that at Scratchells Bay, near the Needles, the
layer of flints can be traced distinctly ; at the base it is
384 WATER : ITS ORIGIN AND USE
absolutely vertical, and it curves over in a grand arch
which was obviously once continued over where the
Channel now is.
We must again go back to the time when the greensand
and chalk were continued across the Weald. The rivers ran
down the slope of the dome, and gradually weathered back,
a process still in operation, carrying the chalk in suspen-
sion and solution into the sea.
The English Channel is only a valley 130 feet deep at
Dover Strait, but it widens and deepens to 500 feet towards
the Atlantic. It seems probable that the anticlinal axis
of the Weald extended across the Channel and marked the
old watershed from which the rivers at one time ran to the
Atlantic on the one side and to the North Sea on the
other, when the southern rivers of England, with those of
Northern France, ran down the great valley, now the
English Channel, into the Atlantic. The Thames joined
the Rhine, and subsequently the Humber ran northward
into the Arctic Ocean. Along the banks of these rivers
roamed the bear, lion, bison, elk, rhinoceros, hippopotamus,
and elephant, whose remains are abundant in the North
Sea and river valley.
Animal Remains
The writer has on several occasions seen large pieces of
mammoth teeth among the gravel dredged from the bed of
the river Thames, proving that these monsters existed
there in great numbers. The teeth of smaller animals are
also frequently found, and tend to prove that they reached
these districts before this country was severed from the
continent and became an island as we now find it, for the
Channel proper was but a river channel which has since
been widened by the action of the waves.
DENUDATION BY LANDSLIPS 385
Referring to this severance of England from the
Continent, the quotation by Waller is worth repeating :
" Whether this portion of the world were rent,
By the rude ocean, from the continent,
Or thus created it was sure design'd
To be the sacred refuge of mankind."
In previous chapters we have dealt shortly with the
work of rivers in the transportation of matter, formation
of deltas, filling of lakes, etc.
Denudation by Landslips
Landslips are also due to the action of water, the
excessive saturation of the soil by rain causing the slipping
or sliding of the land from a higher to a lower level, thus
assisting the work of denudation. A typical instance of
this is Goldau, a valley of Rossberg Mountain behind the
Rigi in Switzerland, where on 2nd September 1806 a
portion of the Rossberg, 3 miles long, 1000 feet broad, and
100 feet thick, fell into the valley, burying villages with
over 800 inhabitants.
Denudation by Glaciers
When water solidifies, the resulting ice is greater in
volume than the water of which it is formed.
The irresistible power of ice, which forms in the fissures
of the rocks, literally bursts them in pieces, and in time will
disintegrate the hardest rocks, reducing them to powder.
" The Alps are crumbling and being washed away, and
if no fresh elevation takes place, the time will come when
they will be no loftier than their rivals in point of age,
Snowdon and Helvellyn.
"From the summit of Mont Blanc 10,000 to 12,000 feet
of strata have already been removed. The conglomerates
25
386 WATER : ITS ORIGIN AND USE
of Central Switzerland, the gravels and sand of the Rhine
and the Rhone, the Danube, and the Po, the Plains of
Dobrudscha, of Lombardy, of South France, of Belgium
and Holland, once formed the summits of Swiss mountains "
(Lord Avebury).
It has been calculated that at the present rate of denu-
dation the Andes will have disappeared in 9,000,000 million
years ; another estimate is 156,000,000 million years.
This period is, however, more difficult to realise than it
was to calculate ; in fact, it cannot really be brought home
to the mind, the vast duration of time indicated ; if it but
leaves a vague impression, these figures will have served
their purpose well. In Europe we have the huge granite
mountain mass of the Pennine Chain of the Alps, which
includes among its summits Mont Blanc ; in this district,
from an area of about 30 miles long by 10 miles wide, issue
about thirty glaciers, including Des Bossons, Argentiere,
and Mer de Glace.
Here we have an instance of the work of glaciers : thirty
glaciers alone (without taking into consideration the
atmospheric changes, etc.) are at work, slowly grinding
and wearing away this mountain mass. The process is
very slow, but it certainly is very sure.
As these and all other glaciers recede, either periodi-
cally or continuously, and expose their channels at the
lower end, we are able to see the results of the work of
denudation and destruction. On each side are mounds of
debris, the lateral moraines, and, in some cases, medial
moraines as well. We also find the various terminal
moraines, marking the respective stages of retreat.
"In large tracts of Norway and Sweden," says Lyell,
"where there have been no glaciers in historical times,
the signs of ice-action have been traced as high as 6000
feet above the level of the sea."
FORMATION OF PLAINS 387
It is stated that the Isortek Eiver, in Greenland, which
flows from under a glacier, carries away as sediment
4,000,000 tons of eroded matter every year.
All this disintegrated matter is in course of transport
by water slowly but continuously, from the scene of its
destruction.
Formation of Plains, etc.
Rivers also form plains and broads by denudation, and
by the deposit of silt, gravel, etc.
The Norfolk Broads, which rest on drift and alluvium in
some places 150 feet deep, were no doubt formed by bars
being thrown by the sea across the outlets of the valleys
in which they lie, and the consequent silting up of the main
channels by the sediment brought down by the rivers.
All our beautiful valleys were also formed in this
manner ; and the present configuration of our globe is
but the work of disintegration, denudation, transportation,
and reconstruction.
The chalk cliffs, promontories, bays, channels, even the
shingle and the sandy beaches on which the children
love to play, are the handiwork of water.
River Terraces
It is generally agreed that, where river terraces exist,
they represent the shore-lines of ancient rivers and
lakes.
They show us the different levels at which a river
flowed in the ages gone by, under conditions no doubt
very different from anything we can imagine.
Nothing short of a deluge of water must at one time
have assisted in forming these terraces. The enormous
width between the topmost shore-lines compared with the
388 WATER : ITS ORIGIN AND USE
present diminutive beds seems to point to the above con-
clusion.
To obtain an accurate conception of the magnitude of
the work of denudation effected by rivers, let us take two
examples: The valley of the Ticino, which is 12,000 feet
below the highest river terrace ; and, coming nearer home,
though on a smaller scale, the parallel roads of Glenroy, a
narrow valley in Inverness-shire, where we have three
natural terraces at corresponding altitudes on opposite
sides of the valley. The lowest of these is 862 feet, and
the highest 1155 feet above the present valley. These
were no doubt the respective levels of ancient lakes, the
three levels representing three stages of the recession, at
long intervals, of the ancient glacier dams at the extremity
of the valley.
Denudation by the Sea
" So swelling surges, with a thundering roar,
Driven on each other's backs, insult the shore ;
Bound o'er the rocks, incroach upon the land,
And far upon the beach eject the sand."
DRYDEN.
We have seen how rain, rivers, waterfalls, and water
generally carry on this great work. We have but touched
the fringe of the subject, for all previous instances sink
into insignificance beside the mighty sea, a giant among
his brethren at the work of denudation that is going on
all over the world.
" Where has the great destroyer not been the devourer
of continents, the blue, foaming dragon, whose vocation is
to eat up the land ? His ice-floes have alike furrowed the
flat steppes of Siberia and the rocky flanks of Schiehallion
(in Perthshire), and fish lie embedded in great stones of
the Pyramids, hewn in the times of the Pharaohs, and in
the rocky folds of Lebanon, still untouched by the tool.
DENUDATION BY THE SEA 389
" As long as the ocean exists there must be disintegration,
dilapidation, change; and should the time ever arrive
when the elevatory agencies, motionless and chill, shall
sleep within their profound depths to awake no more,
and should the sea still continue to impel its currents
and to roll its waves, every continent and island would at
length disappear, and again, as of old, when ' the fountains
of the great deep were broken up,'
" ' A shoreless ocean tumble round the globe.' "
HUGH MILLER.
Longfellow, in The Lighthouse, gives us a vivid picture
of denudation by the sea :
" It sees the ocean to its bosom clasp
The rocks and sea-sand with the kiss of peace,
It sees the wild winds lift it in their grasp,
And hold it up and shake it like a fleece.
The startled waves leap over it, the storm
Smite it with all the scourges of the rain,
And steadily against its solid form
Press the great shoulders of the hurricane."
Dr Hutton observes : " The billows of the ocean agitate
the loose material on the shore, wearing away the coast
with endless repetitions of this act of power and imparted
force ; the solid portion of our earth, thus sapped to its
foundations, is carried away into the deep, and sunk again
at the bottom of the sea, whence it had originated, and from
which, sooner or later, it will again make its appearance."
We are thus led to see a cycle of destruction and
renewal in the matter of which the globe is formed, and
a system of beautiful economy in the works of nature.
Keferringto coast erosion, Mr Clement Keid, F.R.S., in
a paper on the changes on the coasts of the British Islands,
says : " Our present coasts have not always been where
they are now. About 4000 years ago there set in a rapid
but intermittent subsidence of the land or a rise of the
390 WATER : ITS ORIGIN AND USE
sea. The rise of the sea-level was probably completed
about 3500 years ago, and then commenced the coast
erosion, which we now see. Then our present shingle
beaches and sand dunes began to form, and these constitute
our best protection against further inroads. Some com-
pensation for the loss on the coast we have in the great
gain of alluvial land in sheltered estuaries, though against
this must be set the silting up of harbours."
In the discussion of the paper, Mr E. R. Matthews
stated that no less than 115 square miles of land had
been lost by sea erosion in Holderness.
On 10th January 1905, between St Margaret's Bay and
Dover, a strip of rock about a quarter mile long and esti-
mated to weigh about 250,000 tons, fell into the sea ; and
in January 1906 an enormous mass of Shakespeare Cliff,
between Dover and Folkestone, was claimed by the ocean.
All along our coast there is a more or less continuous
loss of land from the action of the sea. In some parts, as
on the coast of Yorkshire, from Bridlington to Spurn, some
36 miles, the waves erode 2 yards annually. In parts of
the coast of Norfolk and Suffolk, 14 feet a year is claimed
by the sea.
This loss must amount to many square miles in the
course of 100 years ; and though the material is deposited
in other parts, this does not counterbalance the loss which
is apparent, for the formation of new land is so slow that
it is hardly appreciable.
According to some authorities, our east coast especially
is getting smaller, wasting away. The author of the
story of Lost England asserts that " in the last hundred
years a fragment of our kingdom as large as the county
of London has been buried beneath the sea. In Yorkshire
alone there are no fewer than twelve buried towns and
villages. In Suffolk there are at least four. Some
DENUDATION BY TIDES 39 1
eminent geologists who have examined this problem
believe that quite as much new land is created as is lost
by the sea's erosion ; but the farmer at Withernsea, or
Cromer, or Southwold, who loses part of a field, may not
be consoled to learn that in Pegwell Bay, or at Pevensey,
new land is being formed, and that hundreds of thousands
of sheep graze on marshes at Komney, where in Eoman
times there was sea. The land-owners of Norfolk and
Suffolk are justified in approaching the Government to ask
that something shall be done to save ' this England ' from
the waves. There is reason to believe that a large area
might every year be saved from the sea by some such plan
as Rennie proposed for the Wash. At present mere
defensive measures, which prove insufficient, are costing
some of the local authorities large sums. Cromer has
spent 36,000 in protective works, Lowestoft 57,000
Sheringham 19,950, Southwold 13,582, and Felixstowe
16,602."
If the sea is playing such havoc under our very eyes and
in parts where there are attempts to stay its encroachment,
what is it doing on the coasts of the mighty continents ?
It is indeed a question which we cannot answer, but can
only vaguely guess.
Dickens, in the Christmas Carol, says : " The thunder-
ing of water, as it rolled and roared, and raged among the
dreadful caverns it has worn, fiercely tried to undermine
the earth."
Denudation by Tides
'As surely as the pale moon draws,
By nature's fix'd, unerring laws,
The refluent tide of ocean's stream
By magnet power in its cold beam."
ANON.
The tides are the rising and falling of the water of the
sea, which occur periodically (12 hours 24 minutes, on an
392 WATER : ITS ORIGIN AND USE
average, elapse from one high tide to another), and are
caused by the attraction of the sun and moon. The great
tidal wave takes its rise in the Antarctic Ocean. Here only
is there a free water-ring completely encircling the globe,
unbroken by land, and the water is not raised more than
a few feet ; but in other places, where the natural order of
things is interfered with by obstacles in the form of con-
tinents, groups of islands, coast-lines, etc., the rise is from
12 to 70 feet, and the navigation is dangerous. At the
mouth of the Wye it is about 40 feet; Bristol Channel,
36 feet; the Wash, 24 feet; Cromer, 16 feet; Lowes toft,
7 feet ; Wexford, 4 feet. Were the whole earth covered
with water to an equal depth, the tide would flow regu-
larly from east to west and everywhere attain the same
height under the same latitude.
In the Mediterranean there is no perceptible tide.
Byron, in the Siege of Corinth, says :
" There shrinks no ebb in that tideless sea
Which changeless rolls eternally."
The cause of the existing variation is beyond the scope
of our story. We may, however, state that the oceanic
tides do not vary more than from 2 to 3 feet in height ; it
is when the masses of water from the ocean approach the
shore, or roll over shallows, or through channels or gulfs
that the above variation in depth occurs.
In our tidal rivers we have a typical instance of power
practically running to waste. It has been calculated that
if the waters of the Severn were dammed up in the Bristol
Channel, an available power of 240,000 electrical h.p.
could be obtained. This is but a trifling example of the
tidal power that is wasted in rivers only.
Tides form an important factor in the work of denuda-
tion and transportation, carrying sand and solid matter, as
DENUDATION BY TIDES 393
the rivers do, from one place to another, forming flats,
marshes, sands, etc., which in the course of time will rise
above the sea and create new lands.
" As the spring tides with heavy splash,
From the cliffs, invading, dash
Huge fragments, sapped by ceaseless flow,
Till white and thundering down they go."
BYHON.
We have now shortly described the manner in which
the mountains are being gradually carried into the ocean,
swept by tides, and deposited over a large area of its bed.
Were this process alone in progress, in the course of time
(time is here used in the geological sense, meaning, of
course, millions of years) the whole earth would eventually
disappear, and the waters, as " in the beginning," would roll
unobstructed round the globe, and the world would consist
of one universal sheet of water only.
Here we see clearly the absolute necessity of the elevat-
ing forces about which we so much concern ourselves,
earthquakes, volcanoes, subterranean disturbances, and
upheavals, and the less apparent but slow and sure up-
heaval of continents and ocean beds by the gradual cooling
and contraction of the earth's crust ; thus nature counteracts
her work of denudation, that it may not amount eventually
to complete destruction.
We cannot do better than conclude these remarks on
denudation by quoting Sir Eobert S. Ball, who says:
" Change is the order of nature ; many changes, no doubt,
take place rapidly, but the great changes by which the
system has been wrought into its present form, those pro-
found changes which have produced results of the greatest
magnificence in celestial architecture, are extremely slow.
We should make a huge mistake if we imagined that
changes even immense changes are not in progress,
394 WATER : ITS ORIGIN AND USE
merely because our brief day is too short a period wherein
to perceive them."
I would suggest that the reader substitute for the words
" celestial architecture " the words the configuration of our
globe, and it will be found to be as true and forcible as
when applied to our solar system, to which the celebrated
astronomer referred.
Of these immense changes that are still going on, so
slowly as to be noticed but by the keen observer, Tennyson
writes :
" There rolls the Deep where grew the tree.
O Earth, what changes hast thou seen !
There, where the long street roars, hath been
The stillness of the central Sea.
The hills are shadows, and they flow
From form to form, and nothing stands ;
They melt like mists the solid lands,
Like clouds they shape themselves and go."
CHAPTEE XVIII
WATER, HOW OBTAINED
" Drink waters out of thine own cistern, and running waters out
of thine own well. Let thy fountains be dispersed abroad, and rivers
of waters in the streets." Proverbs v. 15, 16.
WE have seen in the foregoing chapters that all sources of
water supply have but one common origin, viz. rain,
snow, etc., from the clouds, and that it ultimately either
evaporates and returns invisibly to the atmosphere, is
absorbed by vegetation, percolates into the earth, or, as
a stream or spring, eventually joins the mighty ocean,
whence it returns, by evaporation, to the clouds.
The importance of a supply of pure water cannot be
exaggerated.
The Eivers Pollution Commission states that : " In respect
of freedom from the most objectionable of impurities,
organic matter (organic carbon and organic nitrogen),
waters range themselves in the following order :
1. Spring water,
2. Deep-well water,
3. Rain water,
4. Upland surface water,
the last being much inferior to the first three."
In respect to wholesomeness, palatability, and general
fitness for drinking and cooking, the waters derived from
various sources may be classed in the following order :
395
396 WATER : ITS ORIGIN AND USE
,,7., , f 1. Spring water.
Wholesome < .
( 2. Deep-well water.
surface water,
rain water.
/ 5. Surface water from cultivated land.
Dangerous < 6. River water to which sewage gains access.
( 7. Shallow well water.
c, . . (3. Upland su
Suspicious < , c,, r , .
( 4. Stored ran
Shallow Wells
We are all familiar with the common shallow well, from
which water is drawn by a hand-winch and rope with
bucket attached, such as is usually seen in villages and in
parts where there is no proper water supply. In Eastern
countries we find still more crude methods of raising water.
Water from this source is usually of the worst descrip-
tion, and is classed as dangerous.
It is surprising how people cling to the fallacy that
their wells contain pure water simply because it looks
clear ; the fact that a cesspool may exist within a few feet
is of no importance to them.
Badly fitting covers allow all kinds of vermin to fall
into the water; defective drains also frequently pollute
it. The writer knew of an instance where, in rainy
seasons, the farmyard pond overflowed into the well, and
yet, miraculously, the folks survived and were apparently
little worse for the contamination.
It is at times amusing, when a shallow well containing
impure water is condemned by the sanitary authorities,
to listen to the heated discussion that arises. The occupier
recalls in anger the various ages of his ancestors who
drank this water, the general trend of the remarks being
that some secret collusion exists between the medical
officer and the water authorities who have supplanted
this beautiful well, and insist on being paid for a far
SHALLOW WELLS 397
inferior water. These shallow wells, supplying only a
cottage or two, hardly deserve the name, as they are in
most cases supplied by a little local percolation. Where-
ever the geological conditions are favourable, a considerable
amount of water can be obtained from shallow wells.
Even in parts of the Sahara Desert the water falling on
the mountains makes its way long distances underground,
and breaks out as artesian springs, or is obtained by shallow
wells sunk into the sand, in which the water is held as in
a sponge.
Deep wells are found in the Egyptian Soudan, where,
in the Province of Kordofan, in the rainy season the water
quickly percolates through the sand, and what does not
disappear in this way evaporates quickly, leaving the
surface parched.
" The downward progress of the water is, however,
stopped by a bed of mica-schist, and the water lies in the
hollows of the same formation. Wells are sunk down to
these depressions and water is met with in more or less
abundance, according to the position in which the well is
sunk ; here there are about 900 wells, in depth varying
from a few feet to 200 feet. But for these wells life in
Kordofan would not be possible."
In Yucatan, however, different geological conditions
exist ; here the inhabitants have to obtain water from cave
springs 1000 feet below the surface.
We have also the larger, and generally deeper, wells for
farm and village use, from which water is obtained by the
help of a horse harnessed to a pole ; by walking in a
circle the rope or cable is wound on to a drum and so the
water is brought to the surface. There is also the common
hand well-pump, and pumps actuated by the wind, which
are too well known to require description.
" Shallow " and " deep " here refer rather to the depth
398 WATER: ITS ORIGIN AND USE
of water in the well than to the depth from the surface to
the water, for some shallow wells, or wells in which
there is only sufficient water to enable the bucket to fill,
are at a great depth from the surface, but the bottom is
only a few feet below the line of saturation, and as a rule
only just below the line of variable saturation, for wells
of this description are quickly pumped dry. The writer
has frequently had to increase the depth of these wells,
in order to continue their supply, owing to the under-
ground extensions of adits, etc., at the adjoining pumping
station.
Deep Wells
If water is required in large quantities, wells pene-
trating far below the line of saturation must be sunk deep
into the chalk and other porous rocks.
A short description of the manner in which deep wells
are sunk may be of interest.
Some persons, when requiring a supply of water, send for
a diviner, with his rod, to point out the most likely spot.
This rod is indeed a source of wonder to many.
In a book before me I find the rod and its use most
carefully described as follows : " A rod, usually of hazel,
with two forked branches, used by persons who profess to
discover minerals or water underground. The rod, which
is carried slowly along by the forked ends, dips and points
downward, it is affirmed, when brought over the spot
where the concealed mineral or water is to be found."
"We will presume that the site for the deep well has
been selected in such a locality, where, judging by the
geological position and not by any hazel-twig manoeuvring,
there is likely to be a considerable amount of free water
in the chalk, passing on to the sea.
Here a strong structure of timber or iron, called a gantry,
SCT/0/V$
WCLL
HOW VffLLS ARC SOHK BfLOW rHf L/NC
(To face p. 398.
DEEP WELLS 399
is erected similar to that shown in the illustration. A
boiler for generating steam and a steam-winch are fixed,
and the work of sinking the well (usually 8 to 10 feet
diameter) is carried on in the usual way, i.e. by digging
down to water, or to the line of saturation.
This sounds fairly simple : in some cases it may be so,
but generally there is some trouble to contend with, either
faulty rocks, large seams of slippery clay, which may at
any moment cause a few tons of material to slip in and
crush the men, rubbly chalk which will not stand alone,
infiltration of water, impure air, and the ever-present
liability of a small piece of rock falling from the bucket ;
such a fragment, when falling from a height, acquires the
volocity of a bullet, and it is not an unusual experience for
a piece to come whizzing by one, and embed itself in the
bottom of the well. These and similar contingencies have
to be provided for and overcome.
Unsound ground is usually remedied by inserting rings
of masonry as the work proceeds, carefully underpinning
each ring as the sinking proceeds, but this method is not
practicable if there is much water to deal with. Eesort is
then had to iron cylinders, which are bolted together in
sections, and so the well is practically one long iron tube,
all objectionable matter being shut out.
This part of the work will bring us to the bottom of the
" sunk well," perhaps 150 feet below the surface, at the line
of saturation and water. (See section, fig. A.)
When this point has been reached, boring tools of required
size (up to 5 or 6 feet diameter) are brought into use.
A large hole is bored from the bottom of the sunk well to
a further depth of, say, 100 feet, as fig. B. The usual method
of sinking cannot be adopted here, as we are piercing the
fully charged rocks, below the line of saturation.
Well-boring is not generally dangerous, but it is a
400 WATER : ITS ORIGIN AND USE
laborious task, and I know of no single employment so
drearily monotonous. In boring on the percussion system
a hardened steel chisel of a width equal to the diameter of
the borehole is attached by rods and a punching chain to
the revolving drum of a steam-winch, which raises the tool
a few feet and drops it with a thud. This process is termed
" punching " ; men control the chisel as it falls, slightly
turning it at each fall or stroke. In this manner a truly
cylindrical hole is bored, or, more correctly, jumped or cut.
When some distance has been cut in this manner, a
cylindrical bucket made of steel, called a shell, with a
hinged door opening upwards, in the bottom, is lowered
into the debris and water, which fills it ; it is then drawn
to the surface and emptied.
There is a system of boring in which this process of
" shelling out " is not necessary, hollow rods being used,
down which water is forced, which escapes at the extremity
of the chisel, through holes provided for the purpose ; this
keeps the debris in a liquid condition, and it overflows
continually at the surface in the form of a thin " slurry " :
where conditions are favourable this is a most economical
and expeditious method.
This process is continued day by day : each day the
chisel works deeper, rods being added, until at last, after,
maybe, weeks, months, and in some cases years, the
required depth is reached (fig. B). But now we have a
well, say, 8 or 10 feet in diameter down to the water, and
only a bore-hole 5 or 6 feet in diameter through the
water-bearing rock. We must have the 8 or 10 feet well
all the way ; how shall we do it ?
We must now, either in a temporary or permanent
manner, fix a powerful pumping engine, then, length by
length, ton after ton, the suction rose and working
barrels, rising mains, valves, rods, plungers, and other
-;
o a
ffl |
X 3
63 O
ADITS 401
necessary machinery, are lowered into the sunk well and
bore-hole, to the extremity of the latter, say, 300 feet
below the surface (fig. B).
The engine is then started, the pumps conducting water
from the 100 feet of bore-hole to the surface, keep the
water pumped down, so that the well may be sunk at
its full diameter to the bottom of the boring, as shown in
fig. C.
When we begin sinking through the fully saturated
rock the work proceeds with greater difficulty, for as we
get lower the pressure against us increases, water spurts,
froths, and bubbles everywhere, rushing to the pump ;
everybody employed is more or less wet continually ;
masonry and steel lining-cylinders are put in if necessary.
At last we reach the depth required ; the engine is stopped
and the men come to the surface ; the well fills with water
and preparation is made to test the yield of the deep-
seated spring.
The capacity of the pumps is known, and the number of
strokes is recorded. From these data the amount of water
is calculated.
Adits
If sufficient water has not been met with at this stage,
adits are driven from the bottom of the well in all
directions, as shown in fig. D, the pumps still keeping
the water down.
Adits are tunnels cut in the chalk. A light, temporary
tram-line is laid down at the bottom of the well and is
extended as the work proceeds, a trolley running to and
fro bringing the excavated chalk to the foot of the shaft,
whence it is drawn up to the surface by the steam-winch
in large buckets.
These adits are driven a considerable distance until
26
402 WATER : ITS ORIGIN AND USE
some fissures or natural pipes are cut and the water
rushes into the adit.
In the photograph we see a typical adit in the water-
bearing chalk 150 feet below the surface, with branches
running in all directions
If any considerable length has to be cut, or if the depth
be great, fresh air must be forced down the well and
carried along the adits to where the men are at work,
for if the air contain more than 30 parts of carbonic
acid in 10,000, it becomes poisonous and will cause
death, as in the open country only 3 parts per 10,000
are found.
One great difficulty, which the reader will appreciate,
is to carry out these underground excavations and at the
same time to maintain the supply of clear water for the
community, for the water coming from the adits in which
the men are at work is of course soiled.
The writer has found it of great utility, and a source of
great economy, where there are several wells, adits, and
engines (all adits and wells being connected on the bottom
level), to provide these separate adits with dams of clay
or concrete, fitted with valves and pipes, so that the water
from the various springs may be kept more or less under
control.
If this be done, and men are working in the adits and
soiling the water, the soiled water can then be isolated
and caused to flow to one pump ; the clear water flowing
down the other adits can be led to other pumps that are
keeping up the supply.
In this way the underground water can be controlled
within certain limits, and where the supply of pure clean
water has to be maintained while the extension of the
underground works is in progress, these means are of great
assistance.
Cliarlex Speiicelayh.
AN ARTIFICIAL ADIT IN THE CHALK.
A, bottom of artificial adit 150 feet below surface.
B, water flowing to pumps.
C C, natural horizontal fissure crossing adit.
D, natural spiral vertical fissure.
E E, laminated clay.
[To face p. 402.
ADITS 403
In some cases it has been found very convenient and
economical to lay mains at this depth and carry the clean
water in pipes for some distance through the soiled water,
in order that the two waters shall reach their respective
pumps (see plan).
When a sufficient supply has been obtained, the
temporary dams and pipes are removed and all the water
flows clear and clean.
This work is surrounded by difficulties, and it is at
times attended by dangers from various sources. If the
pumps break down we must run for life, impeded by
heavy water-boots, etc., wading through water to reach the
well, before the water rises, for we are 250 feet below the
surface of the ground and 100 feet below the rest-level of
the water, and it is trickling or spurting through the
seams ; unsuspected huge pieces of rock may slip in, not-
withstanding every care we have used, for this frequently
occurs. We often hear of accidents, and loss of life by
drowning is not uncommon in carrying out the work of
searching for water in the bowels of the earth. This
should make us more careful than we generally are to
avoid wasting this most precious of nature's gifts.
If great demand is made on the source of supply, in a
few years the water-bearing rock becomes so depleted
that the adits must either be extended or deepened. The
latter course is frequently adopted : periodically a few
feet are removed from the bottom, thus increasing the
depth. These tunnels measure as much as 30 feet from
crown to bottom, having been deepened by degrees, say,
20 feet.
In these cases, unless piers of masonry be inserted at
intervals, the rock would slip in ; timber is used as a
temporary precaution, as will be seen in the illustration.
404 WATER : ITS ORIGIN AND USE
Horizontal Wells and Upward Borings
This heading will probably puzzle some readers, but
boring in this direction is actually adopted. There is
an instance of a well " sunk " in this manner at Folkestone,
where the necessary geological conditions exist which
make it possible.
There, as will be seen by the section, an adit is
driven almost horizontally into the face of the North
Downs, in that part of the Chalk formation called the
marl, which is almost impervious, and above which the
Middle and Upper Chalk strata lie. This adit or tunnel
is extended for a considerable distance, when branches are
driven from the main adit at right angles to the original
direction.
In these adits a number of small borings are made in an
upward direction, piercing the water-bearing chalk above,
and the water passes down through these borings into the
adit, flowing by gravitation into the reservoirs.
In percolating through the chalk the soft rain, which
has an average hardness of only O62, becomes hardened
to an average of 27 ; in other respects it is, as a rule,
absolutely pure and needs no filtration or treatment of
any kind.
Cause of Accidents in Wells
The engineer in charge of well-sinking or adit-driving
operations must be careful to ascertain if there are any old
wells, adits, or disused workings in the vicinity of pro-
posed new works, especially at a waterworks where large
supplies are used, and the normal level of the water
lowered many feet by heavy pumping. He must also see
that the accuracy of any plans relating to old workings is
verified as far as possible.
. . 9 '< He BB
,sB5SI;:
AN ARTIFICIAL ADIT
IN THE CHALK
FORMATION.
To illustrate how an
adit some 150 feet below
the surface, being at first
only 8 feet high, becomes
30 feet high, and fre-
quently, at last, aban-
doned and new ones
formed at greater depths
owing to what is termed
frequent "bottoming
out, " that is, the repeated
lowering of the bottom,
to follow the continued
lowering of the rest level
brought about by exces-
sive pumping; that is,
pumping continuously
more than the amount
of percolation, thus
drawing on the reserve
water stored up in the
chalk.
D. C. Graham.
[To face p. 404.
CAUSE OF ACCIDENTS IN WELLS 405
The water in existing workings, when near to new ones,
must also be kept at the same level in the old as in the
new works. The neglect of these precautions has, to the
writer's knowledge, been the cause of disaster and death on
more than one occasion.
At a certain waterworks in Kent, the line of the old
adits was said to be 15 feet from a point where it was
proposed to sink a new shaft. Presuming this to be
correct, the water in the old workings was allowed to rise
60 feet above the bottom of the new shaft. The work was
almost completed when the accumulated water in the old
system burst suddenly through the side of the well and
two men out of the three who were working on the bottom
of the new shaft or well were drowned.
The distance between the new shaft and the old adit
was proved to be, not 15 feet, as stated, but only 13
inches. No indication was given by the strata, which
was chalk, that the old workings were so near, until a
piece of the side, about 18 inches square, blew out. The
water rose almost instantly to the level of the water in
the old system, 60 feet above the bottom of the new well,
submerging the two men as described.
In sinking shafts for coal at Dover, the water was
allowed to accumulate to a depth of several hundred feet
in a shaft sunk to the Lower Greensand formation.
Another shaft was then sunk in close proximity to the
first, and on nearing the same formation the bottom burst
upwards, resulting in the loss of several lives. This was
brought about by the water not being kept balanced in the
two shafts, the great force exerted by the weight of
water in No. 1 causing the bottom of No. 2 to give way,
when, as the sinking proceeded, it became too weak to
resist the pressure.
In some parts of the world there are very deep wells : in
406 WATER : ITS ORIGIN AND USE
the state of Jaisaliner, in Eajputana, where water is scarce,
there are some nearly 500 feet deep.
In deep wells the noxious gases in the air are a source of
danger, and frequently cause loss of life.
The well-known precaution of lowering a candle should
always be resorted to; if it will not burn, it is certain
that the percentage of oxygen in the air is less than is
necessary for the support of life.
Artesian Wells
We will now turn our attention to the sinking or boring
of artesian wells, so called from the French province of
Artois, where they were first sunk on an extensive scate.
They are perpendicular borings, through which the water
rises to its rest-level, not necessarily the surface, produc-
ing a constant flow of water.
The force by which the water is enabled to rise is
derived from the natural hydrostatic pressure, when the
overlying impermeable strata are pierced ; there must, of
course, be no natural flaw in either the upper or lower
confining layers of impermeable strata, by which the water
might escape and disappear into another formation or
stratum.
Where the water-bearing stratum lies at a great depth
below the surface, this method of boring for water is
usually adopted in preference to the more expensive well-
sinking.
We are naturally, especially in this country, liable to
associate artesian borings exclusively with a domestic
supply of water for our towns and villages ; in other
countries, however, they are also used for purposes of
irrigation. Water for these purposes is usually obtained
from rivers, but where this is not available the under-
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ARTESIAN WELLS 407
ground supplies have been tapped, as in many places in
India, Algeria, and America.
It is stated by W. G. Cox, C.E. (Geographical Journal,
1902), that in the Madras Presidency alone millions of
acres are irrigated from artesian wells. In Central Asia
and Persia 200,000,000 persons depend solely for their
food upon areas irrigated by water drawn from under-
ground sources in the form of wells, springs, etc.
In Algeria, principally in the Sahara, over 329,000
square miles have been brought under cultivation by means
of artesian wells. Here 15,000 borings have been made into
the underground water of the arid deserts.
Artesian wells can be numbered by thousands in U.S.A.
with results exceeding those in any other country.
In Queensland 532 borings are yielding over 350,000,000
gallons per day. Other borings in Australia yield, by
pumping, enormous quantities ; one, for instance, at
Coongoola, 6,000,000 gallons per day.
The preliminary arrangements for making an artesian
well are very similar to those necessary for sinking deep
wells ; but here the boring is continued from the bottom
of the well until no further progress can be made, owing
to the sides of the borings falling in, which usually occurs
if a bed of clay or running sand has to be passed through.
At this period of the work tubes are lowered into the
boring, a steel shoe having been screwed on the end, to
assist in cutting off any obstruction in the passage of the
tubes through the rock, etc.
These tubes prevent the falling in of the sides or the
choking of the bore-hole with debris, and boring may be
resumed, the tool being lowered inside the tubes ; a few
feet are bored and the debris removed, and the tubes are
lowered, or, if necessary, forced down, still further.
This process is continued until the friction on the
408 WATER: ITS ORIGIN AND USE
exterior of the tube is so great that the tubes cannot be
forced further into the earth.
A smaller set of tubes is then inserted through those
already in position ; these have also a steel shoe similar to
the larger ones. The work again proceeds, until at last the
water-bearing stratum is pierced, and the water rises in
the tube. Perforated pipes are then forced down and pro-
trude into the water-bearing stratum. The holes allow the
water to enter the tube, but prevent the sand or rock from
choking the pipe.
There are various methods of carrying out this work,
necessitating the use of different tools.
Should the boring be through hard rock, rows of Brazilian
black diamonds, on which the rock has but little effect,
are embedded in the edges of the tools, projecting so as to
cut through the rocks. This system of rotary boring with
diamonds is the invention of a Swiss engineer, Leschot.
The diamond rock drill is now more or less supplanted
by the shot drill. In this the principle is somewhat similar
to the former, but instead of using expensive diamonds,
hard steel shot run loose, underneath the crown of the
drill ; the pressure on them by the weight above as they
revolve crushes and cuts the rock, leaving a solid core,
which is brought to the surface, the finer debris or slurry
being washed to the surface as described in percussion
boring.
In the Sahara Desert, on the borders of Algeria, artificial
oases have been created by means of artesian wells, from
which water, generally of good quality, is obtained, though
sometimes it is slightly saline, so that by these means
" He maketh the wilderness a standing water, and water-
springs of a dry ground."
Artesian borings seem to have been used here by the
Arabs in bygone days.
THE PASSY AND OTHER BOEINGS 409
Traces of more ancient bored springs are also found in
Lombardy, Asia Minor, China, and Egypt.
In Chicago there is a boring only 5 inches in diameter
which yields 800,000 gallons per day. In St Louis
(Missouri) a well 3147 feet deep yields brine. In Louisville
(Kentucky), one 2086 feet deep, though only 3 inches in
diameter, yields nearly as much as Grenelle, which has a
delivery of about 800,000 gallons per day.
In Budapesth there is an artesian well 3182 feet deep,
and at St Louis, U.S.A., one 3843 feet deep ; one of the
deepest wells near us, at Grenelle, Paris, is only 1798 feet
deep.
The Passy and other Borings
The " Passy " boring, in Paris, is a notable example. The
geological section of the Paris basin shows distinctly that
the water falling on the Lower Greensand at Verdun keeps
the formation charged. (See Geological Section.)
The average depth of the water-bearing strata around
Paris is six times that of the chalk-beds underlying
London.
The Passy boring, which pierces the same water-bearing
strata as the Grenelle, was started on 15th September 1855 ;
it is 1923 feet deep, and has at the bottom a diameter
of 2 feet 4 inches. It throws a continuous stream of water,
54 feet above ground, at the rate of 5| million gallons
per day.
This formation, bearing an enormous supply of water, is
1798 feet below the surface of Paris. It is imprisoned by
the Gault clay overlying it, above which are the Upper
Greensand and Chalk, and finally the Tertiary formation.
When these strata have been pierced, the water
rushes quickly upwards through them, until it finds its
rest-level.
410 WATER : ITS ORIGIN AND USE
The water from the Grenelle boring, when confined in
pipes, rises to 128 feet above the surface.
The operation of sinking this boring extended from 1834
to 1841. During the progress of the work (May 1837),
when a depth of 1254 feet had been reached, the boring
rods broke, and they were only recovered after fifteen
months' incessant labour.
At a depth of 1798 feet the subterranean water-bearing
stratum was reached, and water with a temperature of
82 F. spouted up at the rate of 600 gallons per minute,
corresponding with the amount of the rainfall, which
percolates through the permeable strata of Champagne,
100 miles distant.
Another gigantic boring 5 feet in diameter was sunk
into the Paris basin at La Chapelle in January 1886 ;
another, 6^ feet in diameter, is at Butte aux Cailles ; and
there are many others of small dimensions.
At Aire, in the province of Artois, is a well of this
description from which the water has spouted steadily and
continuously 11 feet above ground for more than a century;
another, in the old Carthusian convent at Lillers, dates
from the twelfth century, and is still flowing.
At Sperenberg, Berlin, there is a boring 4194 feet deep
through rock salt, which produces brine. This is one of
the deepest borings in the world.
At Schladebach, near Leipzig, in Germany, there is a
boring, though not for water, 5631 feet deep; at the
bottom the diameter is no larger than one's little finger.
The increase in temperature recorded in the Sperenberg
boring as the work progressed was as follows :
At a depth of 1000 feet . . 1 P. for each 42 feet.
2000 . . 1F. 57
3000 to 4000 feet . 1 F. 95
At Kissingen, Bavaria, there is a salt spring which
m*m
A TYPICAL ARTESIAN BORING.
(Showing the water overflowing from the top of the tube which conducts it from the water-
bearing strata below to the surface.)
[To face p. 410.
THE PASSY AND OTHER BORINGS 411
throws up a column of water 58 feet high, from a depth
of 18781 feet.
The projecting force here is not hydrostatic pressure,
but carbonic acid gas, generated at the junction of the
gypsum with the magnesium limestone at a depth of about
1680 feet.
The following are the temperatures of the water from
several renowned borings, and they show an average
increase of temperature, due to the earth's internal heat,
of 1 F. for a descent of from 40 to 55 feet :
Crenelle } same 82 F. St. Louis, 73'4 F.
Passy J source, 82 F. Louisville, 76 '5 F.
Kissingen 66 F. Charlestown, 87 '0 F.
As far as England is concerned, some of the most prolific
borings are in Lincolnshire.
Eecently a boring was made at Bourn for supplying
Spalding with water; and here, at a distance of 66 feet from
the surface, chalybeate water was met with: this was
excluded by inserting tubes 13 inches in diameter.
At a depth of 78 feet springs were tapped in the
Lincolnshire Oolitic Limestone, but water rose slowly,
taking twenty-four hours to overflow at the surface.
At a depth of 100 feet the yield increased to 1,872,000
gallons per day. Boring was continued to a depth of 134
feet, the yield at that point being 5,011,000 gallons in
twenty-four hours. This is one of the most prolific
borings in England.
At Scunthorpe, Lincolnshire, a boring was sunk to a
depth of 1767 feet into the New Eed Sandstone. An abund-
ant supply was obtained, free from organic impurities ; but,
to the great disappointment of all concerned, it was found
that mineral impurities were present in excessive quantities,
viz. 388'5 grains per gallon, due, no doubt, to the presence
412 WATER : ITS ORIGIN AND USE
of calciferous beds in the lower sandstones, making the
water unfit for use.
Lincolnshire has also the distinction of possessing the
deepest boring (for water) in the United Kingdom, the
first 400 feet being a sunk well 12 feet in diameter, the
next 1102 feet being reduced to 9 feet in diameter, followed
by a boring 33 inches in diameter 59| feet deep=1561|
feet. "A contract for sinking this boring at Boultham,
Lincoln," says Professor Hull, " was entered into in 1901.
On Sunday, 10th June 1906, the top bed of the New Eed
Sandstone was reached, at a depth of 1561^ feet. The
rush of the water when the formation was pierced could
be heard distinctly above ground, the water eventually
reaching and overflowing at the surface.
" This boring passed through Lower Lias clay 641 feet ;
Rhaetic beds 52 feet ; red marl and sandstone (Keuper)
868 feet into the New Eed Sandstone conglomerate ; which
formation reaches the surface in a broad tableland at an
altitude of 300 to 400 feet above sea-level to the north
of Nottingham, and constitutes the source of supply for
that town, and a large district ranging into Yorkshire. Its
nearest border is about 20 miles from Lincoln.
" Owing to its extreme porosity, its absolute continuity
in the direction of the dip of the beds (there being no
faults between), and the constantly increasing hydrostatic
pressure of the water in the direction of Lincoln, there
are all the conditions for a successful artesian water
supply."
Future developments, however, proved that these san-
guine expectations would not be realised. After allowing
the water to overflow at the surface, and pumping it to
waste for several months, with the hope of improving the
quality, it was found that the water would not be fit for a
public supply.
EXPLODING A CARTRIDGE IX A DEEP BORING TO INCREASE
THE YIELD OK WATER.
[To face p. 412.
BORINGS IN THE MEDWAY VALLEY 413
It was then decided to continue the boring to a depth
of 2200 feet. This was done ; the quality of the water,
however, becoming slightly worse.
Let any who think lightly of the duties of those respon-
sible for maintaining a pure water supply for a community,
digest these few facts, as an instance of disaster which could
not be foreseen, when, after about seven years' (1901-8)
patient, difficult, and anxious work, and the spending of
about 30,000, the result could only be abandonment !
There are innumerable artesian borings all over the
country. At Croydon there are two, yielding, it is said,
1,000,000 gallons per day. Also at Brighton the yield
from similar wells is about 1,000,000 gallons per day.
Sometimes, with a view of increasing the yield of a
boring, a powerful explosive cartridge is lowered, and
ignited by electricity. The result at the surface can be
seen in the picture : here the boring is 400 feet deep in
hard rock, and 7 inches in diameter. This method of
shattering and opening the crevices and fissures frequently
has a marvellous result, greatly increasing the supply
from these deep-seated sources.
Borings in the Medway Valley
Many borings of artesian wells exist in the valley of
the Medway, Kent, and though for yield they are eclipsed
by those of Lincolnshire, some are worth consideration.
The deepest in this district is at Chattenden Barracks.
It is sunk 1162 feet deep into the Lower Greensand, and
water rises to within 100 feet of the surface.
The next of importance, at Chatham Dockyard, was
sunk in 1868.
This boring passes through 12 feet of alluvial mud,
gravel, etc., 684 feet of chalk, and 19 1 feet of gault.
414 WATER : ITS ORIGIN AND USE
The rock at the base of the Gault was pierced, and the
Lower Greensand entered at a depth of 903 feet.
Owing to the several reductions in the sizes of the
tubes as the work proceeded, at completion the tube
entering the water-bearing stratum was only 4 inches in
external diameter. The water overflowed at the rate of
115,000 gallons per day, and reached a height of 19 feet
above the surface. The temperature of this water is 65,
that of the Upper Chalk in the adjoining well being 54.
In order to obtain a larger supply a larger boring was
sunk in 1880, the result of which was at least dis-
appointing.
Pumps were inserted in the boring, and water was
pumped from a depth of 122 feet below its rest-level, and
the yield was only 300,000 gallons per day.
This boring was then, for experimental purposes,
carried down to a depth of 965 feet, into the Oxford clay.
This water showed a rise of temperature of 1 F. for every
57 feet.
One other boring only will be mentioned, that at the
pumping station at Luton, Chatham, which was carried
out under the supervision of the writer.
This boring was commenced in one of the many chalk
wells at the station, in which there is a depth of about 80
feet of water from the chalk.
To avoid soiling this water, 20-inch tubes were driven
into the chalk bottom of the well, and through these
tubes the work of sinking the artesian well was carried
out.
Like the dockyard boring this was carried through the
Chalk, Gault, and rock into the Lower Greensand at a
depth of 664 feet.
Here, fortunately, only one reduction in the size of the
tube was made. The 18-inch tubes were carried through
E as
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and driven on to the rock overlying the water-bearing
stratum.
The rock was then pierced, and perforated tubes 14
inches in diameter were inserted.
Water rose to its rest-level, which was found to be
75 feet above sea-level. It had a temperature of 65 F.,
whereas the chalk water in the same well was 53 F.
This boring was a complete success, yielding about
200,000 gallons per day ; but the quantity can be
increased from time to time as required.
This is done by the removal of a tube or tubes from the
top, allowing the water to deliver at a lower level, and so
reducing the hydrostatic pressure on the delivery, in-
creasing the flow proportionately.
These conditions are unique, the same well yielding
both water with 20 of hardness, and soft water having
only "78 of hardness ; the latter welling up through the
tubes inserted in the bottom of the well.
We must not attempt a description of the various fossils
brought to the surface ; but there is food for thought in
one little find that came up in almost the last shell, which
was being emptied when the writer saw a glittering,
irregular piece of matter roll out. It sparkled in the
sunlight as if closely set with diamonds. Upon examina-
tion it proved to be a piece of fossilised wood, probably
oak. The silver streaks and grain can be seen distinctly,
the sparkling stars embedded in it being iron pyrites or
marcasite. Here, 664 feet below the Chalk, Upper
Greensand, Gault clay, rock and Lower Greensand. the
product of ancient forests was found, and brought once
more into the light of day. If we add the 200 feet
removed by denudation, we get a total depth of 864 feet,
and, presuming that this formation was laid down at the
rate of 1 inch a century, we get over one million years.
416 WATER : ITS ORIGIN AND USE
Then a considerable number of millions of years must be
added for the time that has elapsed since the Upper
Cretaceous formation was laid down. Surely this is a
most ancient piece of wood !
Rest-Level and Area of Exhaustion
The rest-level in a well or boring is that level to which
the water rises upon cessation of pumping ; this is fairly
constant if the amount extracted is not in excess of the
percolation. The rest-level and pumping-level vary in
different formations and according to local circumstances.
The writer has known cases where there has been a differ-
ence of over 100 feet; that is, the level is reduced over
100 feet by pumping.
Where these conditions exist, a special kind of pump is
necessary, for here there would be over 70 feet of water
above the pumps ; and should they require repairing or
the valves have to be changed, grave difficulties might
arise; so pumps are used that can be controlled, re-
paired, or changed from the surface, with the well full of
water.
If extensive pumping is carried out, it will be found
that the water-level, or line of saturation, will vary, being
governed by the amount of rainfall absorbed.
If it has been lowered locally by these means, the
original level will be restored on the cessation of the
pumping, if sufficient time be allowed, and provided the
volume abstracted annually is not more than is absorbed
annually from the rainfall.
When the demand increases and more water is required,
either the pumps have to be placed at a lower level, the
well having been sunk deeper and fresh adits driven also
at a lower level, or the existing adits must be extended
ENLARGED SECTION OF THE ARTESIAN BORING, LUTON, CHATHAM, KENT.
(Passing through the Upper Cretaceous formation into the Lower Greensand.)
WELL
too
9-OO-
600
B S
i/A/f VF AHTtSAA T/O/V
S.LEVCL
UPPER AWO
CH/^ LK
i*
.-;-> } HCL BOURN
E > eELCNNlTC P1ARL
-j-.r v
-I"*!
i ~4
?r-*<
- j
SCH/H.K
BED
ROCK
J-LOWE W
'
REFERENCE.
A, top of tube conducting the soft water from the Lower Greensand, 665 feet deep, from
which it flows by hydrostatic pressure.
B, surface of water (hard) from the Upper and Middle Chalk, into which the softer water
falls and mixes with as shown.
C, adits conveying chalk water to the well.
D, the formation that yields the soft water.
[To face p. 416.
REST-LEVEL AND AREA OF EXHAUSTION 417
and more water-bearing fissures cut, thus increasing the
area of exhaustion around the well.
In some formations the area of exhaustion resembles
an inverted cone, the apex of which is formed by the point
at which the water is abstracted, but from experience and
systematic experiment this is found not to apply to wells
in the chalk. The amount of water that can be obtained
in this formation is proportionate to the amount of rain-
fall, the capability of absorption, and the area of the water-
shed in which the operation is being carried out. The
amount actually obtained, however, depends upon the
number and size of the water-bearing courses or fissures
intercepted.
The height to which the water rises in artesian borings
is called the artesian rest-level.
Pumping will reduce the level, as in ordinary wells, and
this reduced level is called the artesian pumping-level.
An instance of this is seen in the artesian wells in the
chalk under London. Where formerly the water rose
above the surface in the lower-lying portions of the Thames
valley, now, through the multiplication of artesian wells,
the amount of water obtained has increased to such an
extent that the level has been greatly reduced, until it
now stands about 100 feet below the Thames, the percola-
tion of the rainfall on the outcrop being less than the
quantity of water pumped.
Reference to the geological section will help to explain
the position of the Chalk formation under London, from
which source all the artesian borings are supplied ; here it
is over 300 feet down to the chalk, which formation is
650 feet thick.
The Thames basin has been riddled with borings ; many
of the large London breweries, railways, prisons, asylums,
as well as the Bank of England, the Mint, and the fountains
27
418 WATER : ITS ORIGIN AND USE
in Trafalgar Square, derive the water from the chalk by
means of artesian wells.
Should these conditions continue, the supply will event-
ually decrease so much that the amount will be limited
to that of the annual percolation ; the accumulation of ages,
stored away in the formation which now supplements the
supply, will then have been used up, leaving the rainfall
only.
The water from the artesian wells sunk into the Lower
Greensand is stored in the interstices between grains of
sand, just as water is stored when poured into a pail
previously filled with shingle.
Great care has to be used in pumping water from these
borings in the sand, for if it be taken too freely the sand
is carried with it, which either ruins or breaks the pumps
or chokes the tubes, and so shuts out the water.
Should this occur, special tools are employed for the
removal of the sand, and the water is again enabled to flow
up the tubes.
The manner in which this water, of a distinctly
different character from that found nearer the surface,
bubbles up from depths of hundreds of feet, is not
generally understood.
A short time devoted to the study of this phenomenon
will prove its simplicity so far as the work of nature is con-
cerned. The work of sinking deep borings is, however,
beset with difficulties. The wells consist of a shaft, sunk
or bored through impermeable strata into a permeable
or water-bearing stratum.
The water obtained from this source is derived from the
rain falling at the outcrop of the permeable stratum,
generally many miles from the spot where the well is
being sunk, and percolating into the formation.
This water is confined, and unable to rise to the level it
s *
~ /.
WATER FROM LAKES AND RIVERS 419
otherwise would reach, by the impermeable strata over-
lying it. When these have been pierced the water is
forced up the artesian tube by the hydrostatic pressure,
due to the level at which the water (as rain) was received.
(See Geological Section.)
Water from Lakes and Rivers
" Streams never flow in vain ; where streams abound,
How laughs the land, with various plenty crown'd ! "
COWPER.
A very large proportion of our supply of water is
derived from the lakes and rivers.
Some lakes are preserved exclusively for this purpose.
The natural Loch Katrine, in Scotland, for example, is used
as a reservoir for the supply of water to Glasgow ; it has
an area of 3000 acres, and a capacity of about 5,600,000,000
gallons.
Some natural lakes have their water-level artificially
raised by dams, so that a greatly increased amount of
water is made available, as in the case of Thirlmere, from
which Manchester derives its water. Where these con-
ditions prevail, the impervious stratum of the watershed
or gathering ground is of clay or rock.
The amount of water obtained from lakes and rivers, as
in the case of wells, is in proportion to the area and the
rainfall, less, of course, the amount of annual evaporation,
etc. Here, in the rainy seasons, the water rapidly finds
its way back to the sea in the form of rivers, unless it be
impounded.
It is estimated that, on the Scotch and Welsh hills,
60 inches out of the rainfall of 70 inches is available,
evaporation claiming only 10 to 12 inches per annum.
Many large towns obtain their water from these sources.
Unlike the well and spring waters, which are generally of
420 WATER : ITS ORIGIN AND USE
a high standard of purity, the streams, rivers, and lakes
contain more or less matter in suspension, gathered up,
as we have seen, by the water in its journey over the rocks ;
hence its lower place in the scale of purity of waters.
This impurity must be removed before the water is
used for supply ; for this purpose it is passed over filter-
beds, and if the work be efficiently carried out, all
objectionable matter should be removed.
These upland waters differ considerably in their
chemical composition, according to the rock on which
they fall and the soil by which the rock is covered:
vegetation and many other things tend to give each its
own peculiarity.
Water from the Elan Valley, from Lake Vyrnwy, etc.
The manner in which artificial lakes are formed by
impounding the waters of streams or rivers may be
described briefly as follows:
If water flowing from a spring or a stream be taken
by any water authority, compensation can be claimed by
those who previously had the use of the same.
Hence the term "compensation water," which is the
amount of water given or passed down the stream to
enable manufacturers and others to continue their re-
spective works as before the waters were impounded. In
this way they do not suffer any loss, for when the dam
is completed, the flood water that originally ran to waste
is stored, and the working power of the stream is increased.
Thus all benefit : a town is supplied with water, the mill-
owners get a regular and efficient supply in times of
drought, when otherwise there would be but little water
in the stream, and the damage from floods arising from
heavy rainfall, or melting of the snow, is averted.
In underground water, however, it is different. If a
well be sunk in any locality, and pumping operations
deprive a community of its water, there is no redress,
there being no legal title to underground water.
A typical instance of a supply for a large community
from these sources is found in the city of Birmingham,
which now obtains its water from the rivers Elan and
Claerwen, tributaries of the Wye.
This watershed has an area of over 70 square miles, the
average rainfall being 63 inches per annum, and the
storage will be sufficient to provide 75,000,000 gallons a
day for 200 days, in addition to 27,000,000 gallons a day
for compensation water, or the amount of water allowed
to flow continually down the valley for the requirements
of those who were users of water before dams were con-
structed across the valleys.
Strong dams of masonry were built to impound the
water. The bed of the river at the lowest dam (Caban Coch)
is 700 feet above mean sea-level, the top water-level being
822 feet above the sea. The Peny-Gareg Dam is 945 feet,
and the Craig-yr Allt-Gosh Dam 1040 feet above sea-level.
Thus a vast body of water is accumulated, turning the
once peaceful valley into a series of artificial lakes.
When this scheme is fully completed there will be six
artificial lakes retained by six massive dams of masonry
varying in height from 98 to 125 feet, and in length from
500 to 900 feet. The first four only of these reservoirs
have a combined top-water area of 1000 acres, and contain
12,700,000,000 gallons.
The water is conducted from the reservoirs, by means
of large iron pipes, to Birmingham, a distance of 80 miles.
The complete scheme will cost about 6,000,000.
Liverpool obtains its water from a similarly constructed
artificial lake, Lake Vyrnwy, in Montgomeryshire.
422 WATER : ITS ORIGIN AND USE
One of our illustrations of the Vyrnwy reservoir shows
the excavation of the trench for the massive dam in pro-
gress. In the centre of the valley the depth down to the
solid rock was 60 feet, the width of the trench at this
point being 124 feet.
This splendid example of waterworks engineering is
more or less typical of all dams of this kind ; it has a top
length of 1350 feet and a width of 20 feet, and has to sus-
tain a body of water 70 feet deep. The total height of
the masonry, in the centre of the river valley, from the
rock to top water-level, is about 140 feet.
This artificial lake has a surface area of 1100 acres, and
will supply 40 million gallons per day to Liverpool, a
distance of 68 miles, the aqueducts passing through the
bed of the river Weaver, and under the bed of the river
Mersey.
The surface level of this lake is about 550 feet above
the reservoirs at Prescot, into which the water is delivered.
Manchester, in like manner, also derives its supply of
water from Thirlmere, which is a natural lake in the Lake
District, but its level has been artificially raised 20 feet,
to a height of 554 feet above sea-level.
When this lake has been raised to its full extent, it will
be 584 feet above sea-level, over 3 miles long, and 793
acres in area, containing 8,135,000,000 gallons, which will
provide 50 million gallons a day for 160 days, even if no
rain should fall. The reader has seen how remote these
chances are in the Lake District.
From Thirimere to Manchester is 95 miles, and provision
is made to convey 50,000,000 gallons a day this distance.
When we consider these distances over which water has
to be conducted, and the great pressure some of the pipes
must be capable of withstanding, and then see the old
wooden pipes through which the water passed to supply
WATER JFKOM LAKE VYRNWY 423
our ancestors in the great Metropolis and other places,
we can realise the stride that has been made in this branch
of engineering. The first attempt to supply London
with water by mechanical methods was in 1581, the
conduits fed by springs being no longer sufficient for the
increasing population.
The Corporation of London granted a lease to Peter
Morrys, of Dutch nationality, who erected a water-wheel
under the first arch of London Bridge ; this was actuated
by the tide, and drove the pumps which forced the water
through the pipes in the streets.
This first mechanical supply of water to the Metropolis
only extended to Gracechurch Street. In the presence of
the Lord Mayor, as the result of his invention, Peter
squirted a fine jet of water over St Magnus Church steeple.
" This performance," says G-. P. Bevan, F.S.S., " so pleased
the city fathers, that they granted the Dutchman a lease
of the Thames water for 500 years, including the ground
on which his forcier stood, and one of the arches of the
bridge, wherein to erect more works. All this was granted
at the very moderate rental of ten shillings a year, and it
is quite certain that no inventor ever got such good terms
out of the city either before or afterwards.
" Two years later the knowing Peter obtained another
arch, also for 500 years.
" When in 1601 the New Eiver scheme was first proposed,
Peter sold his right to Eichard Soane for the sum of
38,000. Soane then applied to the city, and obtained a
lease of one more arch."
We must not, however, be led into a further description
of this ancient supply, interesting as it may be. It is, how-
ever, stated by the same writer that " far-seeing citizens,
who had acquired property in the lanes on the riverside,
laid claim to a wayleave, which was such a disagreeable
424 WATER: ITS ORIGIN AND USE
form of water-rate that a popular commotion took place
in the time of Edward III., with the result that the above
was remedied."
He concludes that it was no doubt this sharp practice
of " the brigands of the lanes " extorting revenue in
this manner from the citizens, that set Peter Morrys's
ingenious brain to work.
The water pipes of this period were merely trunks of
trees roughly trimmed to shape, bored out, pointed, and
recessed to fit each other.
Aqueducts
"It is entertaining to observe how little springs and rills, that
break out of the sides of the mountain, are gleaned up, and conveyed
through little covered channels, into the main hollow of the aqueduct."
ADDISON (Italy, near Rome).
In ancient times, before the introduction of iron pipes
for the conveyance of water to a distance from the reservoir,
aqueducts were built for this purpose.
These were used extensively by the Komans, and were
in some instances works of considerable magnitude, as
will be seen in the pictures. They consist of tiers of
arcades ; the upper tier, upon which is formed the water
channel, is more clearly defined in the second picture.
Many aqueducts remain in various parts of the
continent of Europe ; generally as ruins, but some are
still in use.
The Aqua Marcia, 56 miles long, which was constructed
146 B.C. and restored in 1869, now brings a supply of
water to Rome from the Sabine Mountains.
In Rome we have also the Porta Maggiore, commenced
A.D. 38, which was completed in ten years. This has a
double water channel, one above the other. One was con-
structed to bring water from a distance of 45 miles,
AQUEDUCTS 425
the other 62 miles; the arches at one place being 109
feet high.
There are twelve others that assisted in supplying water
to the city of Rome, but space will not admit of a description.
The Pont du Gard, of which we give an illustration, in
the south of France, 14 miles from Nismes, consists of three
rows of arches, striding across the valley of the river
Gardon. It is built of large stone blocks, and has a
total height of 180 feet, the upper arcade, which contains
the water passage, being 882 feet long. It is indeed
a grand monument of the Roman occupation of France,
and is said to have no rival for lightness, boldness, and
beauty of design.
At Segovia, in Spain, another example is to be seen. This
was also built by the Romans. In places it has two tiers of
arcades, reaching the height of ] 02 feet. Its length is nearly
3000 feet, and it is considered to be one of the finest
works of antiquity.
We have also illustrations of the Roman aqueducts at
Merida and Terragona in Spain, the latter being 876 feet
long and 83 feet high.
Swinburne, in his Travels in Spain, writes : " This
aqueduct is not only an admirable monument of antiquity
for its solidity and good mason's work, which have with-
stood the violence of so many barbarians, and the incle-
mencies of the seasons during so many ages, but also
wonderfully beautiful and light in its design."
Another similar witness of Roman occupation is to be
found at Mayence. Here the ruined aqueduct is 16,000 feet
long. Other ruins exist in Dacia, Africa, Greece, and many
other parts.
There are, however, aqueducts of more modern construc-
tion now in use in many countries, but they are now
constructed principally in connection with canals, though
426 WATER : ITS ORIGIN AND USE
some of them are used for the purpose of waterworks
supplies ; one, which conveys the water to New York, may
be seen at Croton, U.S.A. It is one of the most magni-
ficent works of this kind, but we dare not attempt a
description for want of space.
The Coolgardie Water Supply
Before closing this chapter, a few particulars of this
kind of work in a foreign country will be of interest, and
we will take the water supply of the Coolgardie Goldfields,
Western Australia, as an example.
These great groups of mines at Kalgoorlie and
Coolgardie are some 363 miles in a direct line from Port
Fremantle. The area is practically waterless, the rainfall
being 7 '14 inches, and the evaporation is equal to 82'6
inches, with a temperature often over 100 F. in the
summer.
Gold was discovered here in paying quantities in 1892,
near the present town of Coolgardie. When the great
rush of 1893 set in, the want of water caused indescribable
suffering, and many men died from typhoid fever.
Here inferior water, hardly fit for human consumption,
was worth 2s. 6d. per gallon, and even at this price the
supply was very limited.
As the mines developed, salt water containing 30 oz.
of saline matter to the gallon was found in the lower
levels. This was condensed and sold at 70s. per 1000
gallons, and typhoid fever still raged for want of an
adequate supply of pure water.
In 1894 the railway was extended to the goldfields
(Southern Cross to Coolgardie, 130 miles), and the cost of
the water for the railway alone amounted to 1000 per
day in the summer. It was then decided to obtain water
Mrs Aubrey Le Blond.
RUINS OF A ROMAN AQUEDUCT AT MERIDA, SPAIN.
Mrs Aubrey Le Blond.
PUENTE DEL DIABLO, TARRAGONA, SPAIN.
[To face p. 426.
THE COOLGARDIE WATER SUPPLY 427
from the Helena Eiver, near Mundaring, in the Darling
ranges, 30 miles from Perth. A gigantic dam of concrete
was built across the river, closing up the valley. This
dam is 760 feet long and 100 feet high, and the founda-
tions were carried down nearly 100 feet below the level
of the river.
The thickness of the dam varies from 85 to 120 feet,
tapering to 15 feet at the top. In this way an artificial lake
was formed, 8 miles long, with a capacity of 4,600,000,000
gallons of water, the watershed area being 850,000 acres,
chiefly granite hills, the water being exceptionally good.
The next consideration was to pump these 5,600,000
gallons per day, a distance of 330 miles, against a pressure
equal to a head of 2700 feet, at the rate of 2 feet per
second, through a main having a diameter of 30 inches.
This main consists of 60,000 pipes, each 28 feet long, ^
to | inch thick, weighing about 1 ton. They are tested
to a pressure of 400 Ibs. per square inch, and about 76,000
tons of steel plate were used in their manufacture.
To do this work twenty pumping stations were erected
along the route of 330 miles. These will consume, in the
course of twelve months, if working continuously, 30,000
tons of coal
We in England have many obstacles to overcome in
obtaining and distributing a supply of water, but they fade
to insignificance compared with the scheme referred to.
The manufacture of the machinery alone, the packing
and transport of the same by rail, ship, etc., the delivery
of 5000 cases each at its respective pumping station, along
these dreary 330 miles of granite ranges and sandy, parched
plains, with the loss of only one small hydraulic valve, is
a tribute to the splendid management of those who under-
took and carried out such a task in the short period of
twenty-seven months.
428 WATER : ITS ORIGIN AND USE
"We should also remember that all these stations are
many miles from any place where the men could obtain
food or lodging, and that there was a perpetual scarcity
of water.
Before deciding on this colossal undertaking, boring
was tried, a depth of 3300 feet being reached through
granite, in hopes of obtaining water, but the attempt
was then given up.
Where, on account of local conditions, it is impossible
to impound the water in the manner described, as in the
case of the Thames, a certain portion only of the water is
drawn from the river. There is probably no catchment
basin so richly endowed with springs of pure drinking
water as the valley of the Thames. The manner in which
the great Metropolis is supplied with water, its different
sources, the geological and historical facts concerning it, are
of great interest, but we dare not start on such a subject
for want of space.
The following extract in reference to the river Thames
will, however, be of interest :
" The Thames basin includes within its area," says De
Eance :
" 170 square miles of Lias.
931 Oolites.
5 Hastings sand.
13 Weald clay.
453 Greensand and Gault.
2096 Chalk.
945 Tertiary deposits.
" The Chalk above Kingston occupies 1047 square miles,
and the deep-seated springs in this formation maintain the
dry-weather flow of the rivers, which amounts to at
least 350,000,000 gallons per day. About one-third of
this amount is taken for supply (after filtration)."
The amount obtained from this formation is enormous.
Mrs Aubrey Le Blond.
A ROMAN AQUEDUCT, PONT DU GARD.
Mrs Aubrey Le Blond.
THE WATER CHANNEL, PONT DU GARD.
[To face p. 428.
RESERVOIR DAMS 429
The largest water board in the world, the Metropolitan,
supply 6 million persons with water principally derived
from the Chalk.
The amount consumed by this vast population each day
during the month of March 1904 was nearly 200,000,000
gallons ; this was derived from
River Thames . . . 107,219,000 gallons
River Lea, etc. . . 51,041,000
Wells and springs . . 39,962,000
198,222,000
Here we see that the supply from the river is augmented
from wells and borings sunk into the chalk, water from
this source being free from organic impurity. Is it not
wonderful that the sediment of the ancient seas, raised
to its present position, should fulfil such marvellous duties,
absorbing any amount of rain that may fall in the wet
seasons, and dispensing it more or less regularly in dry
weather, when otherwise no water would be available ?
Reservoir Dams
The construction of these dams for impounding the
waters of rivers and forming artificial lakes varies accord-
ing to the geological conditions ; some are perfectly
straight, as at Lake Vyrnwy ; some, like the dam across
the Eifel valley, are constructed in the form of a curve.
This gives additional strength, where the valley is narrow,
and the height of the water to be impounded proportion-
ately great. In this case the dam is 180 feet high, the
depth of water being 150 feet. It is stated that this
reservoir will be 7 miles long. Not only will this artificial
lake prevent serious floods, which have occurred owing to
the destruction of forests, but the waters will also provide
the electric light to the district of Aix-la-Chapelle.
430 WATER: ITS OEIGIN AND USE
The most difficult part of the work, in constructing these
dams, consists in the controlling of the water while the
excavation for the foundations is in progress.
The stream must either be diverted to some other
channel for the time being, or, if a small one, carried in a
temporary aqueduct, clear of the works, until the excava-
tion is carried down to the rock and the masonry is raised
up to the level of the river-bed. The large valves and pipes
are then built in, some few feet of masonry added, and the
stream is then allowed to follow its own course, through
the pipes which have been inserted. In larger schemes
other methods are adopted ; for instance, temporary dams
are made, excluding the water from certain portions of
the river-beds, which are then pumped dry, and thus,
section by section, the dam is raised above the water-level.
The foundations for these works are most important.
After the solid rock is reached, across the valley and up the
flanks of the hills on either side (to top water-level) every
little piece of loose rock is picked off, the mass scraped and
cleansed, so that the rock and dam shall form one homo-
geneous mass. This seems a simple matter, but it is
difficult indeed ; in some cases, as in that of the Nile dam
at Assuan, under pressure of the water the fissures in the
rock became so many little springs, each of which had to
be dealt with separately and controlled, and the water
pumped away while the foundations were being put in.
It is in these first works, that part unseen, the founda-
tion, that the chief engineering problems arise, and on
them the stability of the dam depends. The contour of the
surface rocks has to be traced, however irregular it may
be, down to the solid, even, as in the case of the Helena
dam, to a depth of 100 feet below the river-bed.
No crevice, crack, or fault may be overlooked, or all your
after efforts will be in vain, and the water, under pressure
FILTRATION 431
of a full reservoir, will escape. We can hardly appreciate
the difficulties of the task, or the anxiety that must fill
the minds of those responsible, when these dams are for
the first time subjected to the full pressure they have to
withstand. From this point the work of fixing valves and
overflows, building water-towers, and all the other
engineering contrivances necessary to the distribution and
control of the water, is more or less familiar to every
reader, and a detailed description of them cannot be
attempted here.
There is no set method or design in the construction of
a reservoir : every dam differs in some way from others,
local conditions requiring a special design in every instance;
no doubt exists, however, as to the beneficial effects that
accrue from these and similar works of man's ingenuity.
Filtration
When the dam is completed and the valves closed, the
water fills the lake: here the bulk of the suspended
matter is deposited. Much finer matter, however, has to
be removed mechanically, as no objectionable matter must
be allowed to reach the consumer; therefore, on leaving
the lake or river, the water is passed on to filter-beds,
which consist of large concrete tanks, about 7 or 8 feet
deep, the floors of which are covered with brick, laid so as
to form a network of channels all over the bottom of the
" bed." On the top of these bricks is placed 6 inches of
coarse stone (say from f to 2 inches in size). This is
followed by 3 inches of finer material (f to f inch), 6
inches of still finer gravel (f to inch), then about 15
inches of sand ; on top of this a final layer of 6 inches of
fine sand, 10 per cent, of which would pass through a
screen having 4900 holes to the square inch. According
432 WATER : ITS ORIGIN AND USE
to Mr C. H. Priestley, a bed thus constructed, 200 feet by
75 feet in area and 7 feet deep, would filter 1,000,000
gallons in twenty-four hours, allowing 278 gallons per
superficial foot of filtering area per hour.
By percolation through these beds the remainder of the
suspended matter is removed from the water and is retained
in the sand, but we must remember that only the sub-
stances mechanically suspended are removed ; matter in
solution, or dissolved substances, are not removed by
filtration, for these can only be eliminated by other methods.
From these beds the water passes on to the consumer,
either by gravitation or, where the natural fall is not
sufficient, by means of pumps.
When the filter-beds become foul from use, the water
percolates more slowly and filtration is less perfect ; the
material of the bed is then thoroughly washed in machines
constructed for the purpose, and when thoroughly cleansed
it is used over again.
Covered Reservoirs
Although hard spring water and that from deep wells
may be, and generally is, bright and clear, when exposed
to the direct rays of sunlight it becomes covered with
confervoid growth, which has a most objectionable appear-
ance. That the sunlight is the chief offender is patent,
for open reservoirs in winter will keep fairly free in
this respect for many weeks ; in summer, however, this
growth will attain considerable prominence in a fortnight.
It is to prevent this that " covered service reservoirs " are
constructed ; they are usually placed on elevated ground,
and the pumps deliver the water into them ; it then
flows by gravitation all over the district to be supplied.
These reservoirs are usually constructed to contain enough
water for from seven to fourteen days' consumption.
A COVERED SERVICE RESERVOIR, 5,000,000 GALLONS CAPACITY, IN
COURSE OF CONSTRUCTION.
THE IKON COLUMNS AND GIRDERS THAT SUPPORT THE ROOK, WITH THE
CENTERING TO FORM THE ARCHES.
[To face p. 432.
COVERED RESERVOIRS 433
The first work in the construction of a " covered service
reservoir " is to remove the vegetable soil, and the ground
is then excavated to the desired depth, and a solid bottom
reached ; the whole area is covered with concrete. The
necessary timbering is erected to enable the massive walls
to be carried up ; heavy iron columns are then placed in
rows, to secure the girders that are to carry the roof;
wooden " centering " (in the form of arches) is then fixed
between the girders and covered with concrete ; the whole
of the reservoir is then carefully coated with neat cement
worked to a smooth surface, and made perfectly water-
tight. The arches forming the roof also receive a similar
coat on the outside to ensure that no water shall penetrate
from above. The excavated earth is embanked round the
sides. The vegetable soil previously referred to is spread
on the top and sown with grass, thus protecting the water
from changes of temperature. These reservoirs are, of
course, fitted with necessary supply valves, washouts, over-
flows, etc., which it is not possible to describe in detail ; also
usually an electric water-level transmitter, which sends
down to the pumping station either positive or negative
currents to the electric receiver actuating an electric
recorder, which registers on a roll of paper every variation
in the depth of water, as it rises or falls, during the twenty-
four hours.
Space will not admit of a description of the various
kinds of artificial reservoirs constructed for the storing of
water. But whether it be the ordinary open service
reservoir, or the more expensive but more wholesome
covered reservoir, or the large impounding reservoir,
occupying an enormous valley, with powerful masonry
dams for holding up the water, great engineering skill is
necessary for their construction. Particular mention of
the obstacles to be overcome and the various circum-
28
434 WATER : ITS ORIGIN AND USE
stances to be considered and the forces to be controlled
would take too much of our space.
Badly constructed reservoirs have many times caused
death and destruction through the waters breaking loose.
We all know the old proverb, " Water is a good servant, but
a bad master," as was proved in 1889, when Conemaugh
Lake and reservoir (Pennsylvania, U.S.A.) burst. Johns-
town and district was laid waste, and 9000 people perished.
Artificial Distribution of Water
This branch of engineering requires much skill and
foresight, and applies exclusively to the manner in which
the water is conducted from the reservoir to the consumers,
some near, others many miles away, in valleys or on tops
of hills, those requiring only a domestic supply, and those
using water for factories, breweries, and works of all de-
scriptions. The different sizes of mains must be calculated
exactly so that all may be efficiently supplied, and with
an eye to the probable increase in the demand in various
parts of the district ; in fact, for this work one should be
blessed with second sight, so that he can foretell the
quantity likely to be required at any time from thirty to
fifty years ahead, for the first great expense of dis-
tribution must be planned with a view to its meeting the
demand for many years to come.
This is difficult, for the unexpected usually happens;
the district supposed to offer the best chances of develop-
ment stands still, and a locality not expected to make rapid
strides increases and flourishes beyond all anticipation.
Thus " the best laid schemes o' mice and men gang aft
agley." Shortly, the artificial distribution of water may be
compared to the circulation of our blood ; our throbbing,
beating heart is the pumping engine, which sends the fluid
ARTIFICIAL DISTRIBUTION OF WATER 435
through the larger arteries or trunk mains, at every point
sending off branches to nourish or supply separate parts,
to the extreme limits of the district, which may be com-
pared to our fingers and toes, the limits of our anatomy.
How all these things run in parallels, is strange ; there is
hardly anything in nature which does not point to some
similarity in our very selves ; indeed, we are fearfully and
wonderfully made.
The first mention of an engine is supposed to refer to a
heat engine, made in 130 B.C., by Hero of Alexandria, but
no real progress was made until the sixteenth century.
The first mechanical contrivance possessing any ingenuity
whatever, for raising water, was the Archimedean screw,
named after its inventor Archimedes, a Greek physicist
and geometrician, about the year 287 B.C.
Denis Papin produced a vacuum by condensation, under
the piston of an engine, in 1690. Slavy patented a water-
raising engine in 1698. Newcomen's engine for pumping
water from mines was introduced in 1711.
James Watt, an instrument-maker of Glasgow, when
repairing one of Newcomen's engines in 1763, was struck
by the waste of fuel, and introduced the steam jacket,
which is a means of keeping the cylinder warm by live
steam. He was also the inventor of the modern condens-
ing engine.
From this date improvements and fresh adaptations of the
steam engine followed, the first railway engine, named the
Rocket, being constructed by George Stephenson, in 1829.
The year 1802 saw the first steamboat being tried on
the Firth of Clyde.
These improvements all culminate in the powerful
Parsons turbine, which is now adopted for driving war-
ships, liners, etc., and bids fair to supplant the recipro-
cating engine. But we must resume our story.
436 WATER : ITS ORIGIN AND USE
A full description of the various kinds of pumps used
for raising water would be out of place in the present
volume. Briefly, however, we have the suction pump (the
common household pump), which only removes the atmo-
spheric air or pressure from above the column of water in
the pipe. If a perfect vacuum be created, the water will
rise only to the height of about 32 or 33 feet, according
to the height of the barometer : but the water rises only
to a height in proportion to the power of the pump to
create a vacuum. The efficiency of the suction pump,
therefore, is limited.
The force-pump, however, will, as its name implies,
force water to any distance and height, provided sufficient
power is available.
The method by which we ascertain the amount of power
required to raise a given amount of water from a well of
certain depth in a given time, and pump it to a reservoir
at a certain height situate at a certain distance, forms but
one of the everyday problems that come before a water
engineer, but a description of the calculations involved
would hardly be of interest to the general reader.
In addition to the foregoing there are also centrifugal
pumps, pulsometer pumps, and the air-lift pump. The
last of these has no valve whatever, the water being raised
to the surface by compressed air alone.
CHAPTER XIX
USE, ABUSE, AND WASTE
The Use of Water
" Flowing waters have not only power to wash out material stains,
but they also clear away the cobwebs of the brain the result of
incessant work and restore us to health and strength." LOKD
AVEBURY.
IN the previous chapters we have closely followed water
in its various forms: from its invisible flight from the
surface of the ocean into atmosphere, its condensation,
and the many forms in which it is returned for our
benefit. In this chapter we will endeavour to trace a
few of the important duties it fulfils.
The everyday domestic uses to which this marvellous
and necessary fluid is put we will not discuss : its indis-
pensability in this direction is patent to all. Its circula-
tion through, and the amount of it contained in, the
tissues of animals is also a matter of general knowledge ;
and that in one way or another, if we wish to keep in
good health, we must consume about one twenty-fifth of
our own weight of water per day, is sufficient proof of
what a short time we could exist without this precious
gift of water.
Some of my readers, however, may not be aware of the
fact that men and animals generally can subsist for a
longer period without food than without water.
437
438 WATER : ITS ORIGIN AND USE
There are, so far as I am aware, few exceptions to this
rule.
The camel is, as we well know, designed by nature
to do an enormous amount of work in arid deserts,
covering many miles of parched sands under a heavy
burden, with but little inconvenience from want of water.
A camel has been known to travel 510 miles in forty days
and only drink 6 J gallons of water on the journey, drinking
3 gallons on the thirty-second day and 3 gallons on the
fortieth day.
It has been stated that a camel has existed for two
months without water.
The manner in which the vegetable kingdom relies
almost exclusively on water for its life and propagation
may also be passed over.
No doubt irrigation forms the most important work of
water, and to its work in this manner we will devote some
serious attention.
Irrigation
" The rivers of God are full of water ; thou preparest their corn,
for so thou providest for the earth."
Irrigation is the art of increasing the productiveness
of soils by the artificial supply of water to them.
Here in England there are but few districts that do not
receive an ample supply of water in the form of rain, and
a serious drought is of rare occurrence.
Famine is usually associated with drought, or failure of
crops from want of rain. One of the greatest famines of
history occurred when the overflow of the Nile failed for
seven successive years. This was about the year 1060.
Two provinces of Egypt were wholly depopulated, and in
another, half the inhabitants perished.
It is, however, stated that " the worst famines or
IRRIGATION 439
periods of great scarcity recorded in Britain were in the
years 272, 306 (Scotland), 310, 739, 823, 954 (lasting
four years), 1087, 1193, 1251, 1315, 1335, 1353, 1438, 1565,
1748, 1795, 1801. Some of these were occasioned not by
drought but by excess of rain."
Excess of rain has also contributed to the list of these
disasters. Torrential rains destroy seeds and crops, and
cause rivers and lakes to overflow their banks, which are
not able to retain the abnormal quantity of water.
Water, again, in the form of hail, does incalculable harm
to crops ; but fortunately hailstorms are only local in their
effects, rarely exceeding an area of 60 miles long by 6
miles in width, and usually of much smaller area.
Many parts of the world are not so blest ; some periodi-
cally experience long droughts, and but for some system
of irrigation, large tracts of land would become useless and
go out of cultivation, which is in itself a great loss to
mankind, as well as the famine and death which follow in
the wake of such a catastrophe.
Darwin mentions the " gran seco " or the great drought
at Buenos Ayres in 1827-1830, where at the lowest
estimate a million head of cattle perished, and dust ac-
cumulated to such an extent as to obliterate all boundaries
and landmarks, and people could not tell the limits of their
estates.
It is in such regions as these that resort is had to irriga-
tion, or the artificial means of watering the land by storing,
diverting, and distributing the flood water of a river or
rivers.
The primary conditions for successful irrigation are,
therefore, a sufficient supply of water, and that at such an
elevation as to admit of its being stored up in flood time,
preparatory to being drawn off into the irrigation canal
formed for this purpose.
440 WATER : ITS ORIGIN AND USE
The practice of irrigation has existed for many ages,
both in India and in Egypt, where the remains of ancient
systems have been discovered.
In Australia especially irrigation is greatly needed : the
dreaded drought and loss of cattle and crops from want of
water is only too well known.
"It is estimated," says a correspondent of the Daily
Telegraph (24th April 1906), " by the U.S.A. Reclamation
Service, that in the West some 50,000,000 acres could be
won from the desert by irrigation. Of this area, about
the size of England and Scotland together, 10,000,000
acres have already been rendered productive, at a cost of
18,000,000. This reclaimed area now yields every year
harvest valued at 30,000,000, and supports a population of
2,000,000 souls. That would seem to be a fair investment.
The difficulties of the problem in Australia are not greater
than they seemed in the Far West. The crying want of
the Southern Continent is water. Cannot the Australian
people do something better with the waters of the Darling,
the Lachlan, and the Murray, than pour them into the
Southern Ocean ? "
An article in the Geographical Journal, by Captain
C. H. Buck, illustrates strikingly what may be done in
tropical lands by irrigation. This contribution relates
especially to the Punjab, where the rivers Chenab, Jhelam,
Ravi, Beas, and Sutlej have all been tapped, and deserts
turned into productive country. The Chenab irrigation
canal serves 3,000,000 acres, and yields a net profit to the
State of 450,000 a return of 23 per cent, on the capital
cost. The crops raised are worth 4,000,000 sterling.
The other works are similarly profitable. Some idea of
the magnitude of these undertakings may be formed from
the fact that the main line of the Chenab Canal is 250 feet
wide, carries nearly 11 feet of water, and discharges 10,800
THE NILE AND THE ASSUAN DAM 441
cubic feet per second about fourteen times the quantity
ordinarily discharged by the Thames at Kichmond. The
Eavi River sometimes runs short of water, whereas the
Chenab has a surplus, and a work is designed which will
feed the Ravi from the Chenab. By means of these
schemes a large and prosperous population has been settled
on what used to be waste lands, and famine in the Punjab
is practically a thing of the past.
The Nile and the Assuan Dam
Egypt has been the scene of vast works of this
description.
In 1843 French engineers commenced a great dam
or barrage across the river Nile at Cairo, but the work
was not completed.
Since the country came under British influence, this
work has been completed, and so efficiently, that the
summer flow is actually all drunk up by the land, and
none goes on to the sea, the level of the river below Cairo
being only the same as in the Mediterranean.
The White Nile rises in the great lakes of Central
Africa (3800 feet above the sea, and about 2000 miles
south of Cairo), viz. Victoria Nyanza, Albert Nyanza, and
Albert Edward Nyanza. It is fed on its way north-
wards by the Gazelle and Sobat rivers, and joins at
Khartoum the Blue Nile, which rises in Lake Dembea and
the Abyssinian mountains. The river is then known as
the Nile. At 200 miles north of Khartoum it is joined
by its only tributary, the Atbara. The Nile enters Egypt
at Assuan, 1125 miles north of Khartoum and 750 miles
from the Mediterranean.
The water begins to rise about the end of May. In
August and September it is in full flood, being charged
442 WATER : ITS ORIGIN AND USE
with rich, fertilising mud, which the Atbara and the Blue
Nile bring down from the Abyssinian hills, while the
White Nile carries the decayed vegetation from the
swamps of Fashoda.
The discharge of the river during this period rises from
14,000 cubic feet to 353,000 cubic feet per second.
The mud deposited by the Nile has been proved by
analysis to consist of
Water -11
Carbon -09
Oxide of iron ...... '06
Silica -04
Carbonate of magnesia .... '04
Carbonate of lime . . . . '18
Alumina '48
1-00
The White Nile does not attain its maximum until a
month later than the other two rivers.
There are two systems of irrigation in Egypt, basin
irrigation and perennial irrigation. In the former case the
Nile when in flood is turned on to the land, where the
mud is deposited ; the water covers the land to a depth of
5 feet for about forty days, and is then turned into the
river again, and under this system one crop per year is
obtained.
With the perennial system the land is irrigated all the
year round, and two crops are obtained every year from
this portion of the ground.
The Assuan Dam extends across the valley, as shown
in the illustration. The waterway, when in flood, is 1530
yards wide, with a maximum depth of 56 feet, when the
top water-level will be 348 feet above sea-level.
The storage capacity of this enormous reservoir is esti-
mated at 37,612,000,000 cubic feet.
THE NILE AND THE ASSUAN DAM 443
To control this enormous amount of water and to empty
the reservoir there are provided 180 large sluices fixed at
four different levels.
The full length of this dam is 6400 feet. It is built
principally of granite and cement, for which purpose 75,000
tons of the latter, made from the Chalk formation, to
which such frequent reference has been made, were sent
from England.
The excavations for the foundations of this dam had in
places to be carried down five times deeper than was anti-
cipated. This work was carried out in a most trying
climate, the summer temperature (for three months) being
from 108 F. to 115 F. in the shade, and at times as high
a temperature as 120 F. was recorded, the mean tempera-
ture at night being 85 F. ; and sometimes it did not fall
below 100 F. at night.
On some days in June the thermometer in the sun
registered 160 F., and no day during the month less than
140 F. There is, therefore, little wonder that cases of
sunstroke, some fatal, were of daily occurrence among the
men employed.
The work occupied 3| years, and cost 2,450,000, or
about 10 per million gallons of water impounded.
The benefit to the vast population consequent upon
the construction of this dam has already been most
apparent.
In the year 1907 the Nile was the lowest on record.
This would have involved the death of thousands, for in
past times a low Nile meant not only famine, but all the
diseases that go hand in hand with starvation and un-
wholesome food : but this work of man's construction has
changed all, and a low Nile now, if not producing plenty,
at any rate no longer brings in its train misery, suffering,
and starvation.
444 WATER : ITS ORIGIN AND USE
The Temple of Philse
At first the dam was to have been of such height that
the Temple of Philae, situated on an island in the middle
of the river, about 1 mile above the dam, would have
been submerged, but under the existing scheme the water
only rises to the floor of the temple.
A considerable amount of time, ingenuity, and money
was expended in underpinning and strengthening the
foundations of this temple, so that the submerging of the
base should not cause its destruction.
It has, however, now been decided to raise the height of
the dam by 7 metres, or about 22 feet. The raising of the
existing dam was the only possible plan. No other
suitable place for a dam could be found, which would
give such enormous storage, although an exhaustive
survey of the Nile valley from Wady-Halfa to Khartoum
was made.
The quantity of water stored by the new dam will be
2^ times greater than is impounded at present.
This additional water will irrigate about one million
acres of land, at present untilled and unproductive, and it
is estimated that the increase in the value of the cotton
crop, made possible by this heightened dam, will be between
3,500,000 and 4,000,000 sterling annually.
The cost of adding these 22 feet to the dam will be
1,500,000, which figure includes the compensation to
the inhabitants of Nubia whose lands will be submerged.
The work will occupy six years.
The raising of this dam will further submerge the Philae
Temple, and it is with regret that we hear that it will be
covered for about five months annually. Many opinions
are given as to the effect of this submersion : it probably
means eventual destruction.
THE TEMPLE OF PHIL^S 445
Irrigation works are also contemplated, and will no
doubt shortly be carried out, whereby the waters of the
Gash will be utilised to enrich the plains in the neighbour-
hood of Kassala.
Extensive irrigation works have also been carried out
in India. In Sinde 80 per cent., and in the North-
West Provinces 32 per cent., of the cultivated area is
irrigated.
The Ganges and Jumna Canal, opened in 1854, alone
irrigates 3,000,000 acres. It has a main artery 525 miles
long.
The Ganges, 200 miles from its mouth, spreads out,
forming a mighty delta which, during the annual inundation,
has the appearance of an immense sea : here hundreds of
miles of rice-fields are submerged, the ears of grain only
appearing on the surface.
For the irrigation of the Lombard Plain, 762,000 cubic
feet of water per minute are drawn off by canals.
The water not only supplies moisture, but furnishes
mineral constituents, etc., that it gathers on its journey
from its source, and so manures as well as irrigates.
The river Orinoco, in South America, in the rainy season
inundates vast plains, forming a large expanse of water as
far as the eye can reach.
Eeferring to these and similar works of man, Hartwig
says : " By planting or destroying woods, he is able to
compel nature to a more equitable distribution of her gifts.
In marshy and low countries he may remove the super-
fluous water by drainage, and increase the productiveness
of arid plains by judicious irrigation. Thus man is the lord
and master of the earth, but hitherto he has done but
little to reap all the advantages he might have obtained
from his dominion."
446 WATER : ITS ORIGIN AND USE
Canals
Canals are really artificial waterways, and form generally
short routes for the passage of ships and barges bearing
passengers or merchandise.
The most important of these is the Suez Canal, which
connects the Mediterranean with the Red Sea, a distance
of about 100 miles. It was begun in 1859 and finished
in 1869. It has no locks. It is of great importance, and
shortens the journey from London to Bombay by 4800
miles, for before it was constructed all vessels had to sail
round the Cape of Good Hope.
Canals existed in Egypt before the Christian era. They
are mentioned by Aristotle, Pliny, and others.
The Mahmoudieh, in Lower Egypt, connecting Alex-
andria with the Rosetta branch of the Nile, was dug
under Mehemet Ali, and is 50 miles long by 100 feet broad :
12,000 labourers died in ten months while the work was
in progress; this estimate of the reckless disregard of
human life is, unfortunately, well known to be accurate.
The largest canal in the United States is 363 miles long,
from Buffalo to Albany, connecting the Hudson with Lake
Erie. It has seventy-two locks, and is carried over several
large streams on stone aqueducts ; it was opened in 1825,
and cost 2,000,000.
There are also in America the St Lawrence Canal,
which was made to avoid the rapids on the river of that
name, 70 miles long; the Welland Canal, to avoid the
Niagara Falls, 27 miles long ; and St Mary's Canal, to com-
plete the navigation of the St Lawrence to Lake Superior.
In Holland, where canals were constructed as early as
the twelfth century, we have the great Ship Canal, connect-
ing Amsterdam with the North Sea; also innumerable
smaller canals.
CANALS 447
The Imperial Canal, China, commenced in the thirteenth
century, is said to pass over 2000 miles and to 41 cities.
In France there are 3000 miles of canals. In Germany
the North Sea and Baltic Canal (Kiel), costing 8,000,000.
The Ganges Canal, North India, already referred to, for
irrigation and navigation, from Hardwar to Cawnpore,
cost about 2,800,000.
In this country we have the Caledonian Canal, a
waterway from Moray Firth to Loch Eil and the sea,
passing through the great glen of Scotland, the whole
length, including Lochs Ness, Oich, and Lochy, being 60
miles. There are twenty-seven locks, the highest of which
is 95 feet above the sea. There is also the Manchester Ship
Canal, which cost 15,000,000. In the British Isles there
is a total length of canals of 3800 miles, the earliest being
the Bridgewater Canal (1761-65), 38 miles long.
Locks enable canals to be made where geological condi-
tions prevent the construction of a level waterway. Boats
are transferred from one level to another by the opening,
emptying, and filling of the locks, raising and lowering the
water in them. Locks (on canals) were not invented
until the fifteenth century.
Merchandise can be sent by water for the same amount
of money at least fifteen to twenty times as far as by land.
What an interesting sight it is to see the ships ploughing
their way, laden with the necessaries of life, to and from
our shores. The tramp steamer, the worker of the busy
hive (it has been called the " shuttle in the empire's loom "),
coming and going year in and year out. The mighty modern
ocean liner, exquisitely fitted, and arranged more like a
palace than a ship. Mail-boats, with their thousands of
sacks of correspondence, mostly letters of love and hope to
friends abroad ; linking together nations by bonds stronger
than iron ; by their speed practically bringing all corners
448 WATER : ITS ORIGIN AND USE
of the earth close together, running with such regularity,
seeming to defy the very elements, that their movements
are timed and marked with great accuracy ; considering
the distance, more accurately than some railway trains.
Even in this age of steam we see here and there the tall,
straight mast of some sailing vessel, whose sails and
innumerable ropes remind us of the pre-steam period,
when the oceans were dotted and our rivers crowded with
these graceful but fast disappearing vessels.
May the time be far distant when they will have dis-
appeared absolutely, for little do we realise what we owe to
them in the past ; 'twas in such vessels as these that the
British sailor,by hardships, exposure, and hard work, became
possessed of the mettle which made the nation what it is.
History repeats itself. What if the future should see
these "white-winged clippers" again hold their own
against steam, in the days when the world has learnt the
price it pays for hurry, bustle, tear, and drive, and a slower
pace in all is adopted for our national good.
Here we see the uses of water : borne on its bosom are
the fruit, vegetables, meat, cattle, corn, timber, gold ; but
who could attempt to complete the list of what comes to us
in this manner, or who could find words to express what we
owe to the oceans and rivers for the comforts around us ?
Power of Falling Water
" The work done against gravity in raising water- vapour to the
height at which it condenses to the liquid state, as rain, is converted
into potential energy, like a clock wound up before it has run down.
The height to which a quantity of water is raised by the sun's heat
is a measure of the dynamic power which the water can exert in its
descent." Dr H. R. MILL.
That part of mechanical science which has to do with
the various means of raising, conducting, confining or apply-
ing water as a mechanical power is called hydraulics.
POWER OF FALLING WATER 449
The word power may be used in a variety of senses : it
is used here as denning a capacity for work. Wind and
water were, without doubt, the first mechanical powers
used, followed by heat derived from the combustion of
wood, coal, oil, and gas, steam, and electricity.
Man's control of water is of great and ever-increasing
importance; great strides in this branch of engineering
have been made since our ancestors erected the crude
watermill as a means of replacing animal and manual
labour.
The idea of converting the whole of the power of falling
water into motive power was first suggested to a solicitor
while fishing near an old watermill in Dent Dale in York-
shire, where the amount of power wasted in this manner
attracted his attention, and in it he found a matter
worthy of study. He made a series of experiments, and in
1845 he gave a lecture at Newcastle-on-Tyne on "The
employment of a column of water as a motive power for
propelling machinery."
This solicitor was no other than the renowned Lord
Armstrong, of the famous gun-works at Elswick, and his
experiments resulted in the invention of the hydraulic
crane and other machinery whose motive power is derived
directly from water.
Speaking generally, the power of waterfalls is univer-
sally wasted, though of recent years a considerable increase
in the employment of this force has taken place, chiefly in
connection with the production of electrical energy. The
reason for this is plain : many of the most powerful
sources of this description are hundreds of miles from the
locality where the energy could be utilised, but distance
presents few difficulties to the transfer of the electric
current ; theoretically there is no limit to the distance to
which it may be transmitted.
29
450
WATER: ITS ORIGIN AND USE
Tramways are being worked at Oakland in California
by power developed 140 miles away.
The Californian Gas and Electric Company are also
supplying current at a distance of 350 miles. This is
the greatest distance yet traversed ; here the voltage
is 100,000.
On 19th November 1906 electrical energy equal to 40,000
h.p., generated at Niagara, was delivered at Toronto, the
distance being 80 miles.
A far greater undertaking, however, is in course of con-
struction, whereby the energy of the Victoria Falls on the
Zambesi shall be transmitted electrically to the goldfields
of the Witwatersrand, 600 miles away, by which means a
saving in the cost of working the mines of about a million
pounds annually will be effected. The voltage will probably
approach 150,000, transmitted by cables suspended from
steel towers 1000 feet apart.
The force exerted by falling water depends upon two
factors, the quantity falling and the height of the fall or
" head." The effective energy equals the number of gallons
per minute flowing over the fall, x 10, which gives the
number of pounds of water per minute ; multiply this by
the vertical height of the fall in feet, and we have the
energy in foot-lbs. ; this, divided by 33,000, will be the
horse-power of the waterfall.
One horse-power is equal to 33,000 foot-lbs. per minute.
This factor was first used by James Watt as a means of
comparing the power of his various engines, viz. 33,000
Ibs. raised 1 foot per minute, or 1 Ib. raised 33,000 feet
per minute, or 1000 Ibs. raised 33 feet in one minute,
or any number of pounds raised any number of feet,
the two numbers multiplied together equalling 33,000 per
minute. If the calculation be per second, we must divide
33,000 by 60 = 550 foot-lbs. per second per horse-power.
POWER OF FALLING WATER 451
There are several methods of calculating the available
horse-power of a waterfall.
If the amount of water be given in cubic feet per
minute, this must be reduced to pounds by multiplying it
by 62'28, the weight of a cubic foot ; for example, if 5000
cubic feet are falling per minute over a fall of 150 feet
high, the power would be computed in the following
manner :
Cubic feet Ibs. feet.
5000x62-28x150
33-000
Some, however, adopt the following simple formula (cubic
feet per minute x height of fall X '001887) :
Cubic feet.
5000 x 150 x -001887 = 1415 H.P.
Thus we find that Niagara is at present wasting an
available energy of over 9,000,000 h.p., and the Victoria
Falls 35,000,000 h.p.
It may be more easily remembered if we state that
530 cubic feet per minute gives 1 h.p. per foot of fall.
The practical available energy is, however, considered
to be 80 per cent, of the theoretical amount. A good
turbine will develop this, whereas a steam engine only gives
us about 25 per cent, return in actual work ; this proves
falling water to be by far the cheapest source of power
known.
It is stated that the cost of the power generated at
Niagara Falls is only 0-24d. (pence) per horse-power hour.
As far as the Niagara Falls are concerned, charters
have been granted recently to various companies for the
development of about 900,000 additional h.p. The average
water-power of this fall is said to be equal to 5,000,000
h.p., with a minimum of 4,000,000 h.p. It is also cal-
culated that when all existing and contemplated works
452 WATER : ITS ORIGIN AND USE
are in full operational per cent, of the minimum discharge
of the river will be utilized. Here we have 1,000,000 tons
of water per hour falling 160 feet, so the present and pro-
jected plants should produce a total of 1,000,000 h.p. It
is contemplated that no visible effect on the beautiful fall
will be apparent.
Enormous as these figures are, they are completely
dwarfed by the Victoria Falls on the Zambesi, already
described. The volume is less than that coming from the
Niagara, but the fall is considerably higher. Here even in
the driest seasons, when the flow is least, 500,000 h.p. can
be developed, and in this fall we find running to waste a
power equal to seven Niagaras, or between 35,000,000 h.p.
and 45,000,000 h.p. It is, however, proposed by the
Chartered Company to harness the Victoria Falls and
distribute electrical energy for industrial purposes.
Who can foretell the far-reaching results of such an
undertaking ? Here is power sufficient to supply all
Rhodesia with light and power for many years. This in
itself is sufficient to revolutionise the present conditions
of life in British Central Africa.
New Zealand is also taking up the consideration of
similar works, for it is estimated that there is sufficient
power available in her waterfalls to do all the transport
work and lighting, and to drive all the factories in the
Colony.
At Geneva it is proposed to develop 630,000 h.p. by
the aid of falling water.
" In California, the water of the Sierra Nevada range,
at altitudes up to 9000 feet, covering an area of 550 square
miles, is impounded and carried by powerful steel mains
to the power-house. With a head of 1500 feet, this altitude
would develop a pressure of 645 Ibs. per square inch, a
pressure that only the initiated can fully grasp.
POWER OF FALLING WATER 453
" Here it rotates enormous turbines, and they in turn
rotate dynamos, dispensing power and light over an area
of 26,000 square miles, driving tram-cars, and illumining
the towns 200 miles distant " (Sphere).
Rochester, U.S.A., owes a great part of its prosperity to
the power furnished by the Falls of Genesee, which are
situated within the city limits ; this power is principally
employed in driving flour-mills and other industrial estab-
lishments which exist on a great scale.
" A dam has lately been erected across the Eifel valley
(Aix-la-Chapelle district). It is a semicircular dam 180 feet
high, forming an artificial lake about 7 miles long and
150 feet deep, and holding up about 7,500,000,000 gallons
of water. This water will be utilised in driving eight
turbines of 2000 h.p., which will supply electric light and
power to the factories and towns: 35,000 volts will be
available for the purpose " (Sphere).
A large tangential water-wheel, with a capacity of
13,000 h.p., which has been built for California, when
operated under an effective head of 660 feet, delivers
8500 h.p. It is intended eventually to increase the
pressure by delivering the water through a new pipe-
line under an effective head of 1050 feet. This will bring
the output of the unit up to the full capacity of the water-
wheel, viz. 13,000 h.p., and make it the most powerful
tangential hydro-electric unit in existence. It will operate
at a speed of 300 revolutions per minute, and will drive a
5500 kilowatt generator.
Queensland is awaking to the value of its water power.
A scheme is described in the British Australasian for
utilising the Barron River Falls, near Cairns, Queensland,
to generate electric power. The river has a fall of 700
feet, and pours over the precipice a large volume of water.
Cairns is situated in a rich mineral country, and the power
454 WATER : ITS ORIGIN AND USE
generated at the falls can be used in the treatment of
copper, tin, wolfram, and other ores, found within a wide
area stretching 150 miles inland.
The cataract on the river Yguassu is situated in the
wild and uninhabited regions on the boundary of Brazil
and the Argentine Republic. It is stated that the amount
of water coming over this fall (15,000 feet wide, 210 feet
high) is 50 per cent, more than that of Niagara ; but here
there is little chance of its power being converted to
man's use.
In reference to our waterfalls at home, the following
extract from Science Notes of the Daily Telegraph gives us
a good idea of what is contemplated :
" Whoever possesses a mountain, let him see if he can-
not form a lake or loch somewhere on its slope and so
produce a waterfall. Throughout the world, falling water
according to a paper read before the British Association
by Mr Campbell Swinton, electrical engineer at present
yields to man's use an amount of energy equal to 1,483,390
h.p., of which total Great Britain figures for the insignifi-
cant quota of 11,906 h.p. But more is going to be done.
The British Aluminium Company gets 7000 h.p. from the
Falls of Foyers, and they expect presently to procure
17,000 h.p. from Loch Leven. The North Wales Electrical
Power Company are about to tap Lake Llydaw, on
Snowdon, and hope to obtain 8200 h.p. for every working
day of nine hours. Finally, the Scotch Water Power
Syndicate is peering round the land of the mountain and
the flood in quest of waters that they can imprison at lofty
levels, and so generate electric power. From Loch Sloy,
757 feet above Loch Lomond, they are going to get 6000
h.p., and at Ardlui, higher up, they propose to get
further energy. All around Wales, Cumberland, West-
moreland, Devon, and Cornwall, as well as in stern and
HYDRAULIC RAMS 455
wild Caledonia, local authorities, as well as owners and
syndicates, should be on the lookout. Even a modest
stream that drops several hundred feet may be a source of
power."
When we consider the endless centuries that these
powers have been running to waste, we can but admire
nature's sublime extravagance, or, as expressed by Sir
Eobert Ball, nature's boundless prodigality.
Hydraulic Rams, etc.
The use of water in the working of hydraulic machines
is most interesting.
Water-power is silent and strong, and is capable of
being developed up to a working pressure equal to 14,000
tons, or, on the other hand, to that only sufficient to crack
a nut.
We have hydraulic rams, lifts, engines, cranes, swing-
bridges, railway turn-tables, movable railway platforms,
grids for raising ships above water, and trains, complete
with engines, to higher levels ; presses used in the manu-
facture of oils, sugar, and numerous other industries. By
hydraulic power we bend armour plates for ships, do all
kinds of punching, shearing, and riveting of iron and steel
plates; cutting and bending rails and girders of steel,
stamping and forging ; opening and closing enormous dock-
gates, and raising the massive cantilevers of the Tower
Bridge.
When launching one of our mighty battle-ships, it is the
hydraulic ram that gives it the first thrust out into the
waters. There is no work water will not do under the
influence of and by the aid of man's ingenuity.
We have also the floating dock which, when emptied,
rises, lifting right out of the water our largest ironclads,
456 WATER : ITS ORIGIN AND USE
fully equipped for war, and, as gently, lowering these
thousands of tons back again into the sea.
Some hydraulic appliances use but little water ; others, of
course, require a considerable quantity. Up to the present
time a turbine, recently fixed in Canada, is the greatest
consumer, 400,000 gallons of water per minute flowing
through its inlet, which is 10 feet in diameter.
The hydraulic ram is simply a small piston which
forces water into a cylinder of larger area. There is
practically no limit to the power that can be developed
in this way, the governing factor being the ability of the
cylinder to withstand the enormous strain developed.
If the end of a small tube, say of an inch diameter
and 46 feet long, be inserted upright into a closed cask full
of water, and sufficient water to fill the tube (say 2 Ibs.)
be poured in at the top, this small quantity of water will
transmit a pressure of 20 Ibs. per square inch all over
the 2000 square inches of the cask, giving a pressure of
40,000 Ibs. on the cask, and will quickly burst it.
This simple example of the pressure exerted by water,
with a height of only 46 feet, will give the reader an idea
of the care that must be taken in the distribution of water
to a town from a reservoir at a considerable altitude.
In the town of Chatham, one reservoir, from which a
part of the district is supplied, is over 460 feet above sea-
level, and in some parts of the district the pumping mains,
service-pipes, valves, etc., have to withstand a pressure of
about 170 Ibs. per square inch.
The manufacturing uses to which water is put are too
numerous to attempt mentioning, and the domestic use of
water is well known.
We should not, however, forget the many uses to which
water in the form of ice is put, principally for preserving
food. Enormous quantities are shipped from the Nor-
THE CASCADES AND FOUNTAINS OF THE ROYAL PALACE OF CASEBTA,
NEAR NAPLES.
Mrs Aulirey Le Blond.
THE BATH OF VENUS.
(To illustrate the ornamental uses of water.)
[To face p. 456.
HYDRAULIC RAMS 457
wegian and other lakes ; from Drobak, near Christiania, the
amount shipped is said to be 150,000 tons per annum.
The ice is cut into large blocks. In some places, where
the lakes are at a distance from the sea and at sufficient
altitudes, rough railways are constructed ; the ice then
travels by gravitation down these lines direct to the ship.
Artificial ice is also largely manufactured by various
processes, but not at a sufficiently remunerative price to
prevent the import of the natural article.
We can do little more than record several other uses of
water, including the peculiar property it possesses for
absorbing heat, making it an ideal medium for heating our
homes and conservatories. The work it performs by the
tides and ocean currents, in the shipping world, can only
be mentioned here ; we can also only refer shortly to the
useful and beautiful part water plays in ornamental gardens
and beautiful lakes, fountains, and artificial cascades.
We cannot all have beautiful fountains, and few of us
can boast of one so fine as that in the accompanying
picture, but many who do not might possess a tiny pond,
a little spurting, refreshing jet of water in a snug corner
of their gardens, tastefully surrounded by pieces of old
rock, with ferns and creepers running riot over them.
Water plants, even small pieces, will thrive and bloom;
the Aponogelon distachyon (Cape fragrant water-lily) will
display its fragrant, graceful, curious-shaped flower, re-
sembling the open mouth of a shark exposing its jagged
teeth.
Other equally beautiful water-flowers will in their turn
put forth bloom ; even the despised duck-weed (Lemna
minor), which many consider only fit to be destroyed, will
greatly interest : a few pieces put in will quickly cover the
water with a bright green carpet, most refreshing to the
eyes.
458 WATER : ITS ORIGIN AND USE
Then the great variety of animal life that will exist in
even a tiny pond, even if no more than 4 feet in diameter,
is astounding. Such a pond will give scope for the enlarge-
ment of our knowledge of water plants and aquatic
animals at our very door, thus increasing both our content-
ment and our intelligence.
Only those who have experienced it can form an idea
of the comfort and serenity to be obtained, after a bustling
day of business, by sitting beside such a tiny patch of
water and listening to the gentle dropping from a tiny
jet, perhaps no larger than a darning needle.
Hugh Miller, in giving his advice to young men desirous
of adding to the amount of their enjoyment, says : " Do not
seek happiness in what is misnamed pleasure ; seek it rather
in what is termed study. Keep your conscience clear,
your curiosity fresh, and embrace every opportunity of
cultivating your minds. Learn to make use of your eyes ;
the commonest things are worth looking at. If you are
jealous of others (referring to those better off), there is
only one way in which your jealousy of them can be well
directed : do not let them get ahead of you in intelligence."
Sports and Pastimes
Our story would not be complete should we omit all
reference to the inestimable boon, the tonic to muscle and
brain, consequent upon games and exercises, especially
those intimately connected with water yachting, rowing,
swimming, ski-ing, skating, sleighing, and even snow-
balling, and many other sports.
Eeferring to the benefits to be derived from the study
of nature in the Alps, Tyndall writes : " The glaciers and
mountains have been to me well-springs of life and joy.
They have given me royal pictures and memories that
SPORTS AND PASTIMES 459
cannot fade. They have made me feel in all my fibres the
blessedness of perfect manhood, causing mind, and soul,
and body to work together with a harmony and strength
unqualified by infirmity or ennui."
The opportunity must not be missed to refer to
swimming. How few, comparatively, know the pleasure of
swimming ! Of those that do, the greater part are fair-
weather swimmers : conditions similar to those obtaining
in Hampstead ponds are to them ideal.
One cannot but notice, at the seaside, first, how few
bathe ; of these again, how few swim. Many only clutch the
ropes of the bathing machines and bob up and down with
blue and cold fingers and a colder body. Go down to
the beach on a " choppy " morning ; the bathers can be
counted on the fingers of one hand ! We hear continually
of swimming lessons and prizes, but surely we are on a
wrong tack. The main idea in learning to swim is to save
your own or another's life in an emergency. This is more
likely to occur at sea and in rough weather, when all our
fancy, smooth-water efforts will not avail much. Prizes
for swimming should be given for the best work in the
open sea, not under ideal conditions : a prize thus gained
is one to be proud of. Young folks should be taught how
to enter the sea safely by diving through the breakers, and
how to avoid being hurled by them on to the beach. The
swimming usually taught amounts to little more than a
healthful exercise.
Especially at the seaside resorts, one cannot but notice
the utter absence that exists of any form of encourage-
ment or attempt to get the mass of the visitors to bathe ;
the energy of " the powers that be " seems rather to put a
premium on bathing, especially beach-bathing ; any paltry
excuse is sufficient for them to put obstacles in the way
and discourage the bather.
460 WATER : ITS ORIGIN AND USE
Surely, as a national good, people should be given every
encouragement to bathe, instead of driving them into the
beastly "machines" to extort a sixpence or ninepence
from those who care to pay. But the existing conditions
keep thousands from indulging in the pleasure of a swim.
Why should a father, with three or four boys, be mulcted
in twelve or fourteen shillings per week for a bathe in
the glorious ocean ?
If the local rates are at times used for purchase of
pianos, for children to march to in dusty schoolrooms,
those who are fortunately able to go to the seaside in their
holidays should not be forced to stand, looking with longing
eyes at the beautiful sea, because they do not possess the
sixpence to admit them to a musty bathing machine !
It cannot be denied that the rivers and seas were given
by the same good God that gave the air; surely they
should be as free, and as a national possession should not
be grasped by individuals; and the foreshore, where the
geographical and geological conditions are such as to supply
a national want, should be free for national use.
Of all sports and pastimes, none can eclipse aquatic
sports in their benefit to the human frame: skating,
mountaineering, and snow games come in a good second ;
cricket, football, and the similar games come third, at least
in our story of water. But we must not overlook the
educational advantage of the combination games, such
as cricket and football ; their value in the teaching of self-
denial, discipline, co-operation, and esprit de corps, as well
as individual excellence, is very great indeed.
Waste of Water
We will now proceed to a subject of great interest to
those responsible for the water supply of a town, but not
Mrs Aubrey Le Blond.
TOBOGGANING, DAVOS PLATZ.
[ To face p. 460.
WASTE OF WATER BY FROST 461
generally of interest to the ordinary consumer, viz. the
waste of water.
One of the principal causes of waste is the inevitable
wearing out of the mains and pipes ; sometimes the water
escapes underground for considerable periods. There are,
however, means of locating these leaks, and if careful
records of consumption be kept, the authorities are soon
aware when a pipe has given way, and remedy the defect.
Waste of Water by Frost
The loss of water when a thaw succeeds a severe frost
is enormous.
The accompanying diagram is compiled from the register
of an electrical recorder.
The line ABC represents the amount of water going
out of a large reservoir, to supply a population of about
100,000 persons.
Each separate step or drop in the line indicates that 1
inch of water has gone out of the reservoir. The amount
of water is not given in gallons, as this is unnecessary for
our purpose, the idea being to show only comparative
differences, not defiaite quantities.
The line ABC, which was recorded on the third day
of a rather sharp frost, shows that at 6 A.M. there was
20 feet 8 inches of water (see large figures in centre), while
twenty-four hours later the surface had fallen to 12
feet 6 inches (C).
The following day the atmospheric conditions remained
the same until 6 P.M. (B), when the thaw set in. This was
immediately apparent, the electrical recorder registering a
more rapid loss, caused by the bursting of a considerable
number of pipes about the district ; the line which, if the
thaw had not set in, would have fallen to about point (C)
462 WATER : ITS ORIGIN AND USE
as on the previous day's record, in the twelve hours 6 P.M.
to 6 A.M. fell nearly 4 feet lower (B D). This enormous
loss in only twelve hours will give an idea of what happens
after a more severe frost. The work of repairing all defects
takes a considerable time, and it is found that on the
termination of winter a considerable period elapses before
the district regains its normal state, although the district
is thoroughly inspected at the termination of these
conditions, and every care is taken to see that all repairs
are executed as quickly as possible.
Waste from this cause, serious as it is, is only periodical ;
it is the waste that goes on all the year round, through the
ignorance or neglect (generally both) of the consumer to
this cause principally are due the disgraceful records of
some water boards.
The daily consumption of water per head in some towns
has even reached 50, 60, and 70 gallons, and this where
the population is not noted for its cleanliness ; and the
writer's experience is that the dirtier the family, the less
the use and the greater the waste of water.
In school the young are taught to utilise carefully even
waste food, but I have never heard of any instruction being
given as to the seriousness of wasting water.
If we look carefully into the same diagram, line ABC,
we shall see that from 11 P.M. to 5 A.M. there is a loss of
12 inches (these conditions are normal) for the period of
six hours of midnight, when there should be but little
water consumed. Presuming half only (say 6 inches) of
this is waste, we must remember it is only a quarter of
the day of twenty-four hours, and no doubt the same waste
continues for the remaining three-quarters of the day, and
is included in the first part of the line ; we therefore have
4 x 6 = 24 inches of water from the reservoir per day
running to waste.
WASTE OF WATER BY FROST 463
Line A B C, 20 feet 8 inches to 12 feet 6 inches, recording
a full day's consumption, indicates the withdrawal of, say, 8
feet of water from the reservoir, out of which 2 feet, or 25
per cent, at least, is waste ; so, roughly, in every four days
water enough for one day is wasted. No further remarks
of mine are necessary to show the seriousness of this. I
can also assure the reader that these figures are considered
favourable and satisfactory compared with the experience of
some water boards, and there is no attempt at exaggeration.
Before leaving this diagram, it is of interest to note
that after a succession of hot. dry days the consumption
would, roughly, follow the line A E, which will be seen
to run parallel with that caused by thaw after a frost
(B to D). proving that as far as consumption of water
is concerned a severe winter is as bad as, in fact worse
than, a dry summer; for in summer, on the fall of the
first shower, the excessive demand or use ceases, and a
normal state of supply immediately ensues: this is not
so in winter.
The other line, FGH, is recorded by the well trans-
mitter, to which the smaller figures on either side of the
diagram refer.
It shows that after incessant pumping the water in the
well was reduced from, say, 85 feet to 8| feet (G) ; pumping
was discontinued at 1.40 P.M. ; the water rose in the well
as shown, at first very rapidly, slowing down towards
night, and at the end of 16 hours' rest it had risen to 54
feet (H).
It is from similar records that the diagram (Strength
of Springs) was compiled, which shows conclusively that the
deeper the well is below the line of saturation (generally)
the greater the amount of water ; the strength of the
spring being on the bottom, as is apparent from the curve
on the diagram.
464 WATER : ITS ORIGIN AND USE
Lavish Use OP Abuse of Water
The term waste does not mean even lavish use, of which
there is no doubt a considerable amount, for I have seen a
person use, in the preparation for the table of two cabbages
and a score of small potatoes, enough water to wash or
rather bathe a whole family.
In my own home I have a fountain, which is a source
of great pleasure to me. I need hardly say that, although
the water is not metered, and I do not pay for it, it is
periodically turned on for a short time, for the pleasure
of myself or friends or for the benefit of my fishes ; but as
soon as my friends cease admiring it, it is turned down,
and is never allowed to play unseen or unnecessarily.
I mention this, for it is a common thing for fountains to be
left continually running, day and night, almost perpetually.
I have seen lawn-sprinklers busily at work on a rainy day ;
and the consumer consoles himself that he is paying a small
sum per quarter for the privilege (?) of wanton waste !
The mention of the sprinkler reminds me of a funny
story in connection with this useful appliance. A friend,
who loved the cool appearance of fresh green grass, was,
one hot day last summer, showing his sprinkler to a lady,
who thought it very clever, but said, on turning away :
" But doesn't it make the lawn very damp ? "
Domestic Waste
There is also the individual with a mania for " flushing
the drains," who pulls up the lever of the closet, and in an
ingenious manner puts a clothes-peg on the rod so that it
shall pass water continually, or drives a nail into the wall
at a convenient spot, hooks the waste-preventer chain over
it, to gain the same end, goes off for a fortnight's holiday,
feeling sure that the drains will be clean, etc., on his return
DOMESTIC WASTE 465
(forgetting it may choke them and perhaps flood the place).
These are facts, and unfortunately there are innumerable
similar ingenious contrivances all tending in the same
direction.
There is also our friend who, when washing a carriage,
puts the hose-pipe into the pail, argues with his mate about
the Liberal majority, the Licensing Bill, free trade, or any
other topic likely to lead to the final drink (not of water)
which usually clenches most arguments. He returns in
perhaps one hour, and proceeds to complete the washing of
the carriage. The water has been pouring down the drain all
this time, but what does it matter ? his master pays so many
shillings per quarter for the use of the water ; he evidently
thinks it includes the waste, or he would not permit it.
Similar cases are innumerable ; I will trouble the reader
with only one other instance in conclusion.
A poor woman had heard the water rushing down a
drain in her yard, from a broken pipe, for over four months.
At last the channel by which it had been escaping got
filled up, and the water began to rise in her scullery floor.
It had wet a half-worn-out door-mat, worth only a few
pence, and this serious misfortune led her to inform the
water authorities of the trouble she was in. This broken
pipe had probably been wasting at least 10,000 gallons a
day for four months, or about 1,000,000 gallons of water !
It will be seen from these instances that much waste
is the outcome of sheer thoughtlessness or ignorance.
Nature has supplied us bountifully with water, but our
duty is, irrespective of what we pay, to appreciate the gift
at its true worth, and not to waste it.
We have learned something of the difficulties that have
to be overcome in providing water, or rather in obtaining,
pumping, and distributing it, and this should tend to make
us more careful in its use.
30
CHAPTEE XX
LESSONS FROM NATURE
" Does it not seem to you that there must surely be many things
worth looking at earnestly, and thinking over earnestly, in a world
like this, about the making of the least part whereof God employed
ages and ages, further back than wisdom can guess, or imagination
picture ?
" Happy truly is the naturalist. He has no time for melancholy
dreams. The earth becomes to him transparent ; everywhere he sees
significances, harmonies, laws, chains of cause and effect endlessly
interlinked, which draw him out of the narrow sphere of self-interest
and self-pleasing into a pure and wholesome region of solemn joy
and wonder." CHARLES KINGSLEY (Wonders of the Shore).
NEXT to the study of the distant worlds which engage the
contemplation of the astronomer, our highest aim should
be the study of the world in which we live, and the many
evolutions through which it has passed ; these can only
be traced by diligent research and patient observation.
In this manner the geologist deciphers the Eosetta stone of
our globe, which unfolds such an abundance of evidence
of the goodness of God and the marvellous perfection of
His works.
We have not here discussed the discrepancy between
the various periods given and the Biblical account of the
wonders of the Creation as in the book of Genesis : that
has been done by many able scholars.
No doubt millions of years elapsed between that period
referred to in the words, " In the beginning God created
the heaven and the earth," and the first day of the
Creation, in which " God said, Let there be light."
466
LESSONS FROM NATURE 467
The study of geology will prove, rather than disprove,
the Biblical story of the Creation, if we only look broadly
into the subject.
" There is no employment more ennobling to man and
his intellect than to trace the evidences of design and
purpose in the Creator, which are visible in all parts of
the Creation. Hence, to him who studies the physical
relations of earth, sea, and air, the atmosphere is some-
thing more than the shoreless ocean, at the bottom of
which he creeps along " (Maury).
In the present study of water the reader will have seen
at least many of the wonders worked by its agency.
The subject is so vast here we have but touched the
fringe of it we can hardly take up any book, periodical,
or even newspaper, without finding something in connec-
tion with this most interesting subject.
The first point to be considered, as well as our knowledge
permits, was the manner in which the world was created,
for beyond this we cannot go : our finite minds, our power
of comprehension, must stop there, be we ever so learned.
We have seen that our earth is but one of a little
family, and this family one of innumerable families, for
we are told by Dr Mill that " 100,000,000 stars or suns
have been proved to exist, and still there is no end."
" An infinite of space,
With infinite of lucid orbs replete :
In motion all, yet what profound repose !
What fervid action, yet no noise ! as awed
To silence by the presence of their God."
Darwin, referring to space, in which these countless
worlds revolve, states : " The blue sky tells us there is a
heaven, a something beyond the clouds above our heads."
We have learned that meteorites by the million are daily
burning themselves into dust in their impetuous passage
468 WATER : ITS ORIGIN AND USE
through our atmosphere. And why ? This dust is now
proved to be absolutely essential to the formation of
atmospheric precipitants in the form of rain, etc.
We have also seen how water first comes to be upon the
surface of the earth and in the atmosphere. How it forms
clouds, condenses and falls as rain or snow; how it
becomes impure ; its influence on vegetation and life ; its
composition and properties.
" I have watched," says Professor Tyndall, " clouds
forming and melting and massing themselves together.
It was nature's language addressed to the intellect." He
writes elsewhere on the same subject : " The clouds were
very grand ; some seemed to hold thunder in their breasts,
those at a distance lay like angels sleeping on the wing."
If acknowledged clever, scientific men can draw inspira-
tion and find an education in nature's works, what a grand
opportunity presents itself to us, for
" He who through nature's various walk surveys
The good and fair her faultless line pourtrays,
Whose mind, profaned by no unhallowed guest,
Culls from the crowd the purest and the best."
ROGERS.
We have also seen the influence of water on, and the part
it plays in, natural phenomena ; its beauty in the various
forms it takes ; the many points of interest that surround
it when it takes the form of ice, as in glaciers, etc.
It is equally interesting to us, as we see it in springs
and streams, rivers and lakes, and in the ocean :
" The earth with its store of wonders untold,
Almighty, Thy power hath founded of old ;
Hath 'stablish'd it fast by a changeless decree,
And round it hath cast, like a mantle, the sea."
Reference has also been made to the action of water in
conjunction with the earth's internal heat, causing volcanic
LESSONS FROM NATURE 469
movements of subsidence as well as of elevation, also its
work of disintegration and reconstruction.
"The general inference seems to be that there have
been long periods of subsidence during which strata were
settled in shallow seas, these being followed by periods of
compression and upheaval. The crust was then buckled
into hills and mountains. In Britain these movements
took place long ago, but in other parts of the world
mountain ranges have been built up of recent, strata, so
that we have cause to wonder that the internal forces of
the globe have left us quiet so long, not to imagine that
those forces have ceased to exist " (Aubrey Strahan, F.K.S.).
It is equally interesting to note its work both in nature
and in the service of man. If all these wonders can be
traced in connection with water, what a field is open to us
in other directions, for nature abounds with marvellous
works !
By the study of nature is implied not only " things as
created and existing," but the tracing and following these
things through the changes that they undergo, noting their
causes and effects, for, as Glanville remarks, " we cannot
know anything of nature but by an analysis of it to its
true initial causes ; and till we know the first springs of
natural motions, we are still but ignorants."
Sir Oliver Lodge says : " Every object we come across,
even a stone, raises unanswerable questions : how came it
into existence ? Take a piece of sandstone, for instance ;
what is it ? Compact sand pressed together. What was
sand ? Fragments of previous rock ground to powder.
That rock was therefore compacted sand, and that was
compound of previous rock.
" The earth has gone through long preparation for man,"
and in this sense Sir Oliver considered that the doctrine
of evolution had a religious aspect.
470 WATER : ITS ORIGIN AND USE
" This peak, and those adjacent," writes Professor Tyndall,
" which are similarly shattered, exhibit a striking picture
of the ruin which nature inflicts upon her own creations.
She buildeth up and taketh down, she lifts the mountains
by her subterranean energies, and then blasts them by
her lightnings and her frost."
The study of the wonders of nature which surround us
in no way tends to diminish the mystery and fascination
that we may at first find in it; it rather increases our
desire to learn more. As our knowledge expands our
thoughts will deepen, and we shall be provided ceaselessly
with new wonders that require our consideration and
energy to unravel. In this manner, by pursuing our
inquiries into nature's work, we, however wise, soon
come to realise our own limitations and capabilities, and
have to confess, after all, that we are still surrounded
on every hand by mysteries and wonders passing our
comprehension.
The late Lord Kelvin admitted that, after fifty-five years
of strenuous effort, he had not yet solved many of the great
mysteries that had engrossed his attention for so long;
he could not, for instance, answer the self-imposed question,
" What is electricity ? " although he knew more of the
subject than any living man. Few men, possessing such
knowledge as he, would have been so modest, I fear.
Professor Tyndall, writing in much the same strain, asks
himself a question also : " Are other grander powers still
latent in nature, which shall come to blossom in another
age ? Let us question fearlessly ; but having done so, let
us avow frankly, that at the bottom we know nothing."
The glacier has been compared to human life. Mrs
Aubrey le Blond, an enthusiastic mountaineer, and first
president of the Ladies' Alpine Club, says : " The spotless
snowflake, descending from above, keeps for some years its
ICE-FERNS ON WINDOW PANE.
PORTION OF ABOVE PHOTOGRAPHED NATURAL SIZE.
I To face p. 470.
LESSONS FROM NATURE 471
whiteness and purity. Then the dust that falls upon it
sullies its surface ; its struggles in its life's journey leave it
wrinkled and scarred. It has carried with it many a
burden, sometimes of precious ores and sometimes of
worthless stones and mud ; but as it shrinks and wastes, it
drops them one by one, till at last it lays itself to rest on
the bosom of the earth.
" But this is not the end, for from within it leaps forth
an arrowy stream, that starts on a new existence till it
joins itself with the ocean."
The river is most frequently taken as a symbol of life.
The following comparison was written by a personal friend ;
I give it, for it is full of deepest thoughts :
" And trickling down the mountain side
The rivers, snow sun-melted, glide ;
A murmuring harmony, that flows
Eternal from the eternal snows ;
Heaven's manna on the mountain top
To earth below, first drop by drop,
Then in the rushing river sent,
Leaping iu boisterous descent
O'er crag and scar, and rocky tract ;
Then like the mighty cataract
Bursting in swollen torrents, till
What first began the little rill,
Noiseless and quiet, sweeps and roars
In hoarser current to the shores
Of gorges, or the broader sea,
Lost in its vast eternity.
How like to man, how like our race !
Our starting-point a loftier place,
From God Himself, so small at first,
The infant, scarcely life, has burst
Into the youth, still broadening down
To riper manhood, then the town
And roar of busy commerce, life
In all its changes, headlong strife.
Then hoary age,
Life's silvery foam, the later stage
When, tired with toil, earth's busy roar
It seeks that far-off brighter shore."
472 WATER : ITS ORIGIN AND USE
There are similar lessons and parallels in all water's
work, the boundless ocean, as well as the tiny flower, the
roaring tempest, and the song of the skylark.
Some of nature's wonders thrust themselves upon our
notice by their very magnitude and beauty, so that almost
" he who runs may read " ; but as a rule nature requires us
to " seek and find," and it is by study only that her rarest
beauties are revealed to us.
" Thus studied, used, and consecrated thus,
On earth what is, seems formed indeed for us :
And sees, by no fallacious light or dim,
Earth made for man, and man himself for Him."
COWPEB.
The ceaseless murmur of the ocean waves as they break
upon the shore, which Longfellow calls " the grand, majestic
symphony of the ocean," cannot but attract the attention
of the most idle observer ; but nature's masterpieces are not
so easily discovered there is no royal road to them, only the
student becomes acquainted with them. And what does he
find ? Perfection everywhere ; even the wing of the common
house-fly is of marvellous and beautiful construction.
Surely this teaches us at least one lesson : that nothing is
so small and mean in nature that it did not require infinite
care and thought in its design ; nature knows no jerry-
building ; scamping and make-believe are outside her
domains ; all is done thoroughly. Surely it tells us that
nothing but our very best is acceptable, and our ambition
and aim should be the gift of taking infinite pains with all
that comes to our hands to do.
The pleasure to be derived from the study of nature
must be experienced to be appreciated. This pleasure is
not limited to the rich, the clever, or the man of leisure.
The poor, those of limited ability, or those occupied by
daily labour, can all, according to their gifts, enjoy such
-JJ "*
LESSONS FROM NATURE 473
recreation. How many take country walks and see
nothing, neither bird, flower, butterfly, nor bee ? To such
nature exists in vain.
Let me again refer to the field that nature offers to a lad
of deficient education, whose early life was perhaps one of
stern work, not systematic education. Let him take heart,
for he may succeed where others have failed ; his very
deficiencies may prove an advantage, for some of the well-
educated take so much for granted, presuming on their
knowledge, and so pass over innumerable treasures in
" nature's realm " that are quickly discovered by one who
perforce has had to look for, search after, and find out all
he ever knew ; his very life has made him naturally a keen
observer, and has given him a disposition that will not shirk
the idea of work, which in the study of nature is essential,
for it is almost exclusively a matter of work and healthy
recreation ; the lackadaisical, " slack " youth, be his
education of the best, will be left far behind. There are,
of course, fortunately for science and the world, here and
there men who possess every qualification and advantage,
and the energy necessary to use them for the benefit of
their fellow-men. From such I have not scrupled, as the
reader will see, to draw freely, and quote often, I hope
for the general benefit, their words of wisdom, the result
of education and research, in the realms of which I am
but a casual observer.
Canon Barnet says one of the saddest sights of the
Lake District tourist season is the aimless wandering of
the hard-worked folk, who have waited a whole year for
their annual holiday, and having obtained it, do not know
what to do with it. " They stand, with Skiddaw, glorious
in its purple mantle of heather, on one side, and the blue
hills of Borrowdale and the shining lake on the other, and
ask, ' Which is the way to the scenery ? ' "
474 WATER : ITS ORIGIN AND USE
" How differently nature affects individuals ! " says
Professor Tyndall. " To one she is an irritant which evokes
all the grandeur of the heart, while another is no more
affected by her magnificence than are the beasts which
perish."
What greater real joy can we have than that obtained
in the study of natural works, both in heaven and on
earth ?
" The sun shines brightly from his throne,
Pavilion'd in the eastern sky ;
The thousand tints that deck his crown
In beauty with the rainbow vie !
The modest daisy in the field,
Amidst the meadow half concealed,
The dew that sparkles in his ray
He kisses from his cheek away."
In nature the worker, whether mental or physical, can
find a welcome change, recreation, and rest, a change that
the idle can never know, for true pleasure and recreation
come from within and not from without the man.
Many men roam the world over, exhausting every
pleasure, place, and thing, and still complain of nothing to
interest them.
From them the sublime works of nature cannot extort
a single responsive thought, or call forth the faintest
praise.
Let such beings follow nature in her works : they will
find her a subject for study full of inexhaustible variety,
endless surprises, and astounding revelations.
"The world we live in," says Lord Avebury, "is a
fairyland of exquisite beauty, our very existence is a
miracle in itself, and yet few of us enjoy as we might, and
none as yet appreciate fully, the beauties and wonders
that surround us."
What we do see depends mainly upon what we look for.
Those who love nature can never be dull ; they may have
LESSONS FROM NATURE 475
troubles and temptations, but at least they will run no risk
of being beguiled by ennui, idleness, or want of occupation.
It is said : " Beautiful is God's earth, and beautiful it is
to be a man thereon." We should also remember that it
is possible to have eyes and see not, to hear and not to
understand.
By interesting ourselves in nature we shall probably
prolong our lives, and we shall certainly add to our
pleasure and knowledge.
" I have so long," says Kingsley, " enjoyed the wonders
of nature, never, I can honestly say, alone ; because, when
man is not with me, I have companions in every bee, and
flower, and pebble."
Now that we are approaching the end of our survey, let
us ask ourselves what we have to learn from it? what
does it teach ?
Surely that nothing is permanent, nothing lasting:
" change and decay in all around we see " ; but we see
also renewal (rearrangement, reconstruction), endless
evolution. Applying the lesson to ourselves, we, like
everything in nature, change gradually day by day,
from birth to death, slowly indeed, but surely it is said
that " something dies in us the moment we are born, and
something is born in us the moment we die " ; birth, life,
death, are all part and parcel of our natural existence.
Over the first we have no control, of the second but little
control is in our hands ; the last we should not fear, being
as natural as the first, and probably, if we knew, shrouded
in oblivion at the last, and not so fearful as we think.
This brings us to the crucial point, where to look for
pleasure ; for
" The world can never give
The bliss for which we sigh ;
'Tis not the whole of life to live,
Nor all of death to die."
476 WATER : ITS ORIGIN AND USE
Lord Avebury tells us that it is by no means the most
prosperous men that are the happiest : many are indeed
miserable. " If a man has not got the elements of happi-
ness in himself, not all the beauty and variety, the pleasures
and interests, of the world can give it him. Misfortunes
we must all expect in this beautiful and glorious but com-
plex world, but the darkest shadows of life are those which
a man himself makes when he stands in his own light."
At times a man wearies of his possessions, as a child
does of his toys ; therefore, with our pleasure as with our
investments, " we must not put all our eggs in one basket " ;
put some interest in gilt-edged securities. Get at least
some recreation by the study of nature ; observe her habits,
look into her secrets, whether it be the action of water,
the testimony of the rocks, the wonders of the deep,
the beauties of plants, the mysteries of the heavens, etc. ;
otherwise, if our pleasure comes from relying on others,
or in aimless wandering about in search of new amuse-
ment, we may become bored. Let us seek, anyway, some
recreation from a sure source, where it will not fail us,
whereby we become refreshed, not wearied.
An eminent writer calls attention to the general idea
that the good God created for man all the wonders of
which we have read. That God created our universe and
all the unknown worlds of space for His pleasure, and man
for a similar purpose, may be, but all this marvellous
display was not for man. " Are those immense bodies,"
says Dr Buckland, " the fixed stars, hung up for nothing
but to twinkle in our eyes by night, or to find employment
for a few astronomers ? Surely he must have an over-
whelming conceit of man's importance who can imagine
this stupendous frame of the universe made for him alone."
The same writer, in concluding one of his works, says :
" The whole course of the inquiry, which we have now
;
1 i' %
n M-
\\
:. f'
LESSONS FROM NATURE 477
conducted to its close, has shown that the physical history
of our globe, in which some have only seen waste, disorder,
and confusion, teems with endless examples of economy
and order and design ; and the result of all our researches,
carried back through the unwritten records of past time,
has been to fix more steadily our assurance of the exist-
ence of one Supreme Creator of all things."
Surely this is an ideal conclusion of our study of water.
" The world," says Channing, " from our first to our last
hour, is our school ; and the whole of life has but one great
purpose education."
This will also lead us to look from nature to nature's
God. We may then hope to say :
" This our life, . . .
Finds tongues in trees, books in the running brooks,
Sermons in stones, and good in everything."
THE END
INDEX
Accidents in wells, 404.
Adelsberg Cavern, 161.
Adits, 368, 371, 401.
the making of artificial, 372.
Africa, aqueducts in, 425.
Air. See Atmosphere.
Air-lift pump, 436.
Alcohol, boiling point of, 125.
Altitude, its effect on temperature,
44.
highest reached, 51.
Animal remains, 241, 384.
Antarctic ice, 81.
Antro di Nettuno Grotto, 341.
Apollinaris water, 274.
Aqua Marcia, 424.
Aquarium, an, 136.
Aquatic sports, 458.
Aqueducts, 424.
Arabs, artesian wells made by, 408.
Archimedean screw, 435.
Area of exhaustion, 417.
Arkwright, Captain H., 229.
Artesian rest-level, 417.
wells, 261, 406.
statistics of, 407, 409.
in London, 417.
Artificial distribution of water, 434.
Assuan Dam, 441-442.
Atmosphere, 25.
composition of, 25.
compressibility of, 46.
denudation by, 377.
expansion and contraction of,
48.
height of, 50, 51.
pressure of, 53.
saturation of, 38.
temperature of, 42.
Atmospheric refraction, 40.
Aureolas, 156.
Aurora Borealis, 157.
Aurora Australis, 157.
Australia, water in, 426, 427.
Avalanches, 183.
Azure Cave, Capri, 340.
Barometer, the, 54.
Barometrical pressure, 53.
Bathing, 459.
Behring Strait, the, 149.
Blue Grotto at Capri, 340.
Bovallius, Dr Carl, 298.
Brine, existence of life in, 305.
Buenos Ayres, 439.
California, water power in, 452.
Calms, 73.
Camel, water consumed by, 438.
Canals, 446.
Capillarity of chalk, etc. , 368.
Capillary attraction, 254, 367.
Carbonic acid, 30, 377-380, 402.
gas, 411.
Caspian Sea, 82.
Caves, 161.
marine, 340.
Chalk, 84, 346, 361.
a natural filter-bed, 366.
adits and chambers in, 368-37 1 .
area of, 367.
capillarity of, 367.
composition of, 361.
formation of, 361.
percolation in, 371.
retention of water by, 372.
specific gravity of, 367.
thickness of deposits, 364.
under London, 417.
water in, 367.
Chamberlain Fall, the, 298.
Chenab irrigation canal, 440.
Cherra Pungi, 87, 349.
Cloud-banner, 68,
478
INDEX
479
Clouds, altitude of, 72.
classification of, 71.
colour of, 75.
dust particles in, 77.
formation of, 66.
velocity of, 72.
Coal, consumption of, 104.
formation of, 102.
heat in, 104.
Coast erosion, 25, 330, 388.
Colour, vibrations causing, 42.
" Compensation " water, 420.
Condensation of vapour, effect of
vegetation on, 101.
Conemaugh Lake, 434.
Consumption of water per head, 462.
Continents, height of, 317.
Coolgardie water supply, 426.
Coral, 331.
Coronse, 156.
Covered reservoirs, 432.
Crater. See Volcanoes.
Crevasses, 227.
Crowborough Beacon, 382.
Currents, 333.
Dams, 422-429.
Dead Sea, the, 305.
analysis of, 306.
buoyancy of, 306.
Denudation, 283, 330, 346, 375.
" Dephlogisticated air," 108.
Deserts, extension of, 82.
Devil's punch-bowls, 235.
Dew, 141.
ponds, 143.
point, 17.
Diamonds, temperature necessary to
form, 4.
Distribution of water, 434.
Divers, 322, 323.
Diviners, water, 249.
" Divining-rod," 399.
Domestic waste of water, 464.
Dragon Cave in Majorca, 342.
Drills used in boring wells, 408.
Droughts, 438.
Dust, 150.
Earth, axis of the, 354.
density of, 114.
earliest life on, 365.
formation of, 3.
internal heat of, 20.
size of, 9.
thickness of crust, 5.
Earthquakes, 357.
Eifel valley dam, 429, 453.
Elan valley, 420.
Electricity, 151, 152, 449.
Engines, early, 435.
English Channel, 383.
Erosion by rivers, 281, 284.
coast, 330, 388.
Erratic blocks, 224.
Eruptions, volcanic. See Volcanoes.
Etesian winds, 74.
Evaporation, 31, 34, 83.
Falls of Foyers, 454.
Famines, 439.
Fashoda, 442.
Fata Morgana, 42.
Ferrar Glacier, the, 81.
Filtration, 431.
FingaPs Cave, 340.
Fishes, distribution of, 339.
effect of water-pressure on, 321.
reproductive powers of, 339.
variable specific gravity of,
115.
volcanic, 355.
Fjords, formation of, 342.
Flint, formation of, 362, 364, 383.
where found, 362.
Floods, 186, 439.
Fog, 148.
Foraminifera, distribution of, 363.
Forests, destruction of, 98.
extent of, 97.
Fossils, 241, 345, 415.
Fountains, 457.
Fram, voyage of the, 337.
Freezing, 186.
heat evolved in, 191.
of lakes, 192.
of sea- water, 193.
Frost, waste of water by, 461.
Ganges, the river, 381, 445.
Geysers, 261.
" Giants' cauldrons," 234.
Glacial Periods, 237, 240.
Glaciers, 82, 211, 213.
denudation by, 385.
Gobi Desert, 349.
Graham Island, 359.
Great Salt Lake, the, 305, 307.
Great Kaieteur Fall, 296, 298.
Greece, aqueducts in, 425.
Grenelle boring, the, 409, 410.
Gulf Stream, the, 149, 324, 333,
335, 337.
Hail, 147.
Hailstorms, 439.
480
INDEX
Halos, 156.
Han, caverns of, 164.
" Hardness " of water, 415.
Harmattan, the, 74.
Harvests of the sea, 339.
Heat of the sun, 8.
earth, 8.
effect on vapour and dry air,
17.
of various fuels, 18.
penetration of rays in land and
water, 16.
thermal unit of, 17.
Helena River, Western Australia,
427.
Hoar-frost, 146.
Horizontal wells, 404.
Hydraulics, 448.
Hydraulic rams, etc. , 455.
Hydrogen, 111.
Ice, 186, 194.
artificial, 187.
barriers, 235.
formed in caves, 209.
greatest thickness, 205.
uses of, 456.
Icebergs, 201.
Ice-flowers, 188.
Iceland, 350.
Icicles, 208.
India, irrigation in, 440, 445.
Infiltration, 259.
Intermittent springs, 255.
Irrigation, 438, 442.
Isortek River, the, 387.
Jupiter, 45.
Kaieteur Fall, the, 296, 298.
Kalgoorlie water supply, 426.
Kamsin, the, 74.
Kent, the Weald of, 381.
Kerguelen, 377.
Khasia Hills, 349.
Krakatoa, eruption of, 77, 153, 329,
355.
Lakes, 299.
area of various, 311.
colour of, 313.
deepest, 305.
dried up, 310.
glacier, 236.
in craters, 301.
life in salt, 305.
origin of, 299.
purity of, 313.
salt, 305.
Lakes, surface level of, 304.
temperature of, 312.
with no outlet, 309.
Landslips, 385.
Lava. See Volcanoes.
Lea, river, 429.
Lessons from nature, 486.
Levant mud, 363.
Life, existence of, at extreme tem-
peratures, 266.
origin of, 7.
Light, rate of travel, 40.
production of, 105.
Lightning, 151, 152.
Line of saturation, 255, 416.
Liverpool, 421.
Lochs in Scotland, formation of,
342.
Locks on canals, 447.
Lombard Plain, the, 445.
London, artesian wells in, 417.
first water supply, 423.
the New River, 423.
water supply, 428.
Manchester, 422.
Marine caves, 340.
Mayence, aqueduct at, 425.
Medusae, 327.
Medway valley, borings in the,
413.
Mercury, freezing point of, 125.
Merida, aqueduct at, 425.
Meteors and meteorites, 2, 50, 150.
Mineral waters, 268.
Mirage, the, 42.
Mist, 148.
Mistral, the, 74.
Monsoon, the, 74.
Moon, the, 39, 45.
Moraines, 224.
Morrys, Peter, 423.
Moulins, 233.
Mountains, 344.
age of, 347.
altitudes of, 348.
formation of, 345.
influence on rain, 348.
volcanic, 348.
Nansen, Dr, 337.
Naples, the Bay of, 326.
Nebulae, 2.
Newcomen, 435.
New Siberian Islands, 338.
New Zealand, water power in, 452.
Niagara Falls, 292, 295, 450.
Nile, the River, 438, 441.
INDEX
481
Norfolk Broads, the, 331.
" Northern lights," 157.
Ocean. See Seas.
Ocean currents, 338. See also
Gulf Stream and Polar
Stream.
Original water pipes, 424.
Orinoco River, the, 445.
Oxygen, discovery of, 108.
distribution of, 110.
Papin, Denis, 435.
Parhelia, 156.
Paris, water-bearing strata in, 409.
Parsons turbine, the, 135.
Passy boring, the, 409.
Phila?, Temple of, 444.
Phosphorescence, 327.
Plains, formation of, 387.
Pluveometer, 85.
Po, delta of the river, 382.
Polar exploration, 196.
Polar Stream, the, 337.
Pollution of water, '259.
Pont du Gard, the, 425.
Popocatepetl, 351.
Porta Maggiore, 425.
Power in falling water, 448.
Pressure of water in pipes, 456.
Pumps, 47, 416, 434, 436.
Pumping-level, 416, 417.
Queensland, water-power in, 453.
Radiation, 16, 17.
Rain, absorption of, 82, 84.
analysis of, 92.
cause of, 78, 102.
decreasing rainfall, 81.
denudation by, 378.
distribution of, 85.
dust particles in , 93.
extremes of, 86.
greatest, 81, 89.
"hardness" of, 404.
hot, 4.
influence of trees on, 96, 102.
mountains on, 348.
impurity of, 91, 93.
"luminous," 152.
not always formed in the
clouds, 80.
percolation of, 82.
prehistoric impressions of, 94.
quantity of, 85.
re-evaporation of, 69.
Rain, signs of, 106.
size of drops, 80.
tropical, 88.
total annual, 89.
Rainbows, 155.
Rain-gauge, the, 85.
Rainless districts, 90, 98.
Rain-prints, 94.
Rain-water, hardness of, 93.
impurity of, 93.
Reafforestation, 97, 98.
Reclamation of laud by irrigation,
440.
Rod Sea, the, 327.
Reservoirs, natural, 419.
covered, 432.
dams, 429.
Rest-level of water, 416.
Rhone, water of the, 382.
Rivers, 275.
changes in beds of, 287.
deltas of, 285.
denudation by, 281, 283.
erosive powers of, 284.
lengths of various, 278.
matter in solution in, 283.
matter in suspension in, 281,
286.
prehistoric, 384.
subterranean, 163.
swiftest, 280.
velocity of, 279.
Rivers Pollution Commission, 395.
River terraces, 387.
Roaring Forties, the, 377.
Rocks, absorption of water by
various, 367.
impressions on, 95.
Roman aqueducts, 424.
Rotomahana, eruption of, 351.
Sahara Desert, the, 378, 397, 408.
Salt, 166.
Salt lakes, 305.
comparative salinity of, 309.
existence of life in, 305.
Sand-cones, 225.
Saturation, line of, 255.
Seas, 314, 328-330.
areas of, 316.
colour of, 326.
currents, 333.
denudation by, 388.
depths of, 316, 318, 320.
depths reached by divers, 322.
fishes in, 321.
influx of rivers, 343.
pressure at various depths, 320.
31
INDEX
Seas, temperature of, 319, 322.
Sea-water, 133.
composition of, 135, 315, 332.
distillation of, 135.
freezing point of, 337.
Segovia, aqueduct at, 425.
Selters, or Seltzer, water, 274.
Simoom, 74.
Sirocco, 74.
Slates, origin of, 346.
Slavy, 435.
Snow, 32, 172.
impurity of, 177.
red, 173.
Snow-line, 179.
Solar System, the, 63.
Soudan, the, 397.
South Pole, ice-cap retreating, 81.
Specific gravity of chalk, 367.
elastic fluids, 30.
various substances, 115,
282.
various waters, 307, 309.
heat of various substances, 123.
Springs, 244.
intermittent, 255.
strength of, 463.
submarine, 251.
sulphur, 272.
thennal, 266, 273.
See also Wells.
Stalactites and stalagmites, 159.
Stars, the, 63.
Steam, 117.
latent heat of, 120.
Steam-boat, the first, 435.
engines, 435.
Stephenson, George, 435.
Storms, 151-153.
Strength of springs, 463.
Subterranean rivers, 163.
Sulphur springs, 272.
Sun, corona of, 15.
distance from earth, 10.
heat of, 8, 13, 16, 17, 43.
incidence of its rays, 44.
size of, 10.
weight of, 11.
Sunset, 40.
Swinton, Campbell, 454.
Temperature, Arctic, extremes of,
210.
at various places on the earth,
15.
at various depths, 22, 337,
410, 414.
denudation by, 377.
Temperature, equalisation of, 16.
highest known to science, 14.
lowest artificial, 49.
lowest recorded, 42.
mean, at equator, 337.
of atmosphere, 42, 52.
ranges of, 44.
variations of, 42.
what it is, 1 9.
zero, absolute, 49.
Temple of Philse, 444.
Terragona, aqueduct at, 425.
Thames basin, the, 417, 428.
Thennal waters, 268, 273.
Thermometer, the, 19.
Thunder, 151.
Tide, denudation by, 391.
power of, 392.
range of, 96, 391.
Trade winds, 73.
Trees and rivers, interdependence
of, 101.
effect on health, 99.
climate, 101.
temperature, 100, 102.
famous, 100.
their influence on rain, 96,
101.
See also Forests.
Trilobites, 8.
Turbines, 435, 456.
Twilight, 39, 40, 41.
Typhoon, the, 74.
Upward borings in chalk, 404.
Use of water, 464.
Vapour, 35.
condensation of, 39, 80.
re-evaporation, 69.
Vegetation, effect on condensation,
101.
Vesuvius, 354.
Volcanic islands, 359. See also
Volcanoes.
Volcanic mountains. See Volcanoes.
Volcanoes, 344-857.
active, 351.
eruptions of, 351, 352.
largest active crater, 350.
lava, 354.
number of, 350.
product of, 347.
Vyrnwy Lake, 420, 421, 429.
Water, amount absorbed by chalk,
367.
analysis of, 132-135, 306.
INDEX
483
Water, artificial distribution of, 434.
as a solvent, 265.
- -bearing strata, 371.
boiling point, 19, 168.
classification of, 395.
"compensation," 420.
composition of, 108.
compression of, 125, 126.
congelation of, 124, 125.
consumption per head, 462.
contained in human body, 137.
articles of food, 137.
density of, 124-135.
effects of, 39.
temperature on, 115, 124.
evaporation of, 116.
freezing point, 19.
from lakes and rivers, 419.
wells. See Wells, Artesian, etc.
" hardness " of, 92, 127.
heat required to evaporate, 33.
how obtained, 395.
latent heat of, 121.
molecules of, 112.
of imbibition, 368.
percolation in chalk, 371.
pollution of, 259.
power, 448.
precipitation of lime in, 130.
pure, 91.
salt lakes, 306.
sea-water, 133.
softening of, 131.
specific gravity of, 113.
heat of, 122.
Water, thermal, 268.
use and waste of, 463.
Waterfalls, 290.
Great Kaieteur, 296, 298.
Niagara, 292, 295, 450.
recession of, 284.
Victoria Falls, Zambesi River,
290, 450.
Watersheds, prehistoric, 384.
Waterspouts, 154.
Waste of water, 460, 463.
Watt, James, 435-450.
Waves, height of, 329.
power of, 328, 330.
speed of, 329.
See also Seas.
Weald of Kent, the, 381.
Wells, artesian, 261.
boring, 398, 404, 418.
deep, 397, 398.
pollution of, 396.
shallow, 396.
sinking, 370, 398, 404.
See also Springs.
Welsh hills, antiquity of, 347.
Whirlwinds, 75.
Wind, classification of, 73.
velocity of, 61.
See also Storms.
Worcester Cathedral, revenue from
salt, 170.
Yucatan, 397.
Zero, absolute, 49.
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