UC-NRLF
SB 27D 7fiD
LIBRARY
UNIVERSITY OF CALIFORNIA.
RESEARCHES ON
THE EARTH'S ATMOSPHERE.
WORKS BY THE SAME AUTHOR
FAMILIAR LETTERS ON SOME MYSTERIES OF NATURE. (London, 1876.)
PHOSPHORESCENCE, OR THE EMISSION OF LIGHT BY MINERALS, PLANTS,
AND ANIMALS. (London, 1862.)
NOCTILUCINE, THE PHOSPHORESCENT PRINCIPLE OF LUMINOUS ANIMALS.
(Pamphlet from the Chemical News, 1875.)
THE UTILISATION OF MINUTE LIFE : PRACTICAL STUDIES ON INSECTS,
CRUSTACEA, MOLLUSCA, ETC. (London, 1864.)
METEORS, AEROLITES, AND FALLING STARS. (London, 1867.)
LA FORCE CATALYTIQUE, . ETUDES SUR LES PHENOMENES DE CONTACT.
(Gold Medal, Societe Hollandaise, Haarlem, 1858.)
PHENOMENES METEOROLOGIQUES OBSERVES SUR LE LITTORAL DE LA
FLANDRE OCCIDENTALS. (From the Comptes Rendus of the Paris
Academy, 1857.)
PHENOMENES LUMINEUX QUI ACCOMPAGNENT LES ESSAIMS D'ETOILES
FILANTES. (Id., 1868.)
SUR LES PROPRIETES OPTIQUES DES CORPS APPLIQUEES A L'ANALYSE.
(Gold Medal, Societe Royale des Sciences Medicales et Naturelles,
Bruxelles, 1868.)
OUTLINES OF A NEW ATOMIC THEORY. (4th Ed. London, 1886. Pamphlet.)
TRAITE DE CHIMIE A L'USAGE DES PHOTOGRAPHES. (i Vol. Paris, 1864.)
EXPLOSION ET CHUTE DES METEORES. (Comptes Rendus, Paris, 1869.)
ORIGINE DE L'OXYGENE ATMOSPHERIQUE. (Id., 1893 and 1895.)
AGRICULTURAL CHEMISTRY OF THE SUGAR CANE, (srd Ed. Manchester,
1884.)
MEMOIRE SUR LA FECULE. (Bruxelles, 1855. Pamphlet.)
HEALTH NOTES AND CURIOSITIES OF MEDICAL SCIENCE, (i Vol.
London, 1898.)
VOICE AND VIOLIN, (i Vol. London, 1898.)
FAMOUS VIOLINISTS, (i Vol. London, 1896.)
SCENES FROM THE REIGN OF Louis XVI. (London, 1878.)
(For other Writings, see " The Scientific and Literary Works of Dr. T. L.
Phipson, with a short Biographical Notice," by C. J. BOUVERIE
(London, Wertheimer, 1884), and Catalogue of Scientific Papers of
the Royal Society of London, Vol. IV. and Vol. VII.)
RESEARCHES
ON THE
PAST AND PRESENT HISTORY
OF THE
EARTH'S ATMOSPHERE
Including the Latest "Discoveries and their
"Practical ^Applications
BY
DR. THOMAS LAMB % PHIPSON
AUTHOR OF
"METEORS, AEROLITES, AND FALLING STARS"; "PHOSPHORESCENCE, OR THE
EMISSION OF LIGHT BY MINERALS, PLANTS, AND ANIMALS " J " THE UTILIZA-
TION OF MINUTE LIFE"; "FAMILIAR LETTERS ON SOME MYSTERIES OF
NATURE"; "HEALTH NOTES AND CURIOSITIES OF MEDICAL SCIENCE";
"VOICE AND VIOLIN," ETC.
LONDON:
CHARLES GRIFFIN & CO, LIMITED
EXETER STREET, STRAND.
1901
FRANK RUTTER, ESQ., B.A. (CANTAB.)
THIS LITTLE WORK
IS AFFECTIONATELY INSCRIBED BY
THE AUTHOR
TABLE OF CONTENTS.
PREFACE, . . . Pages xi-xii
INTRODUCTION.
The Science of the Atmosphere Its Numerous and Important Applica-
tions Origin of Modern Chemistry The Theory of Combustion
History of the Chemical Composition of the Air Discovery of
the Barometer, Pages 1-8
PART I.
THE EARTH'S ATMOSPHERE IN REMOTE GEOLOGICAL
PERIODS.
CHAPTER I.
The Atmosphere in the earliest Epochs of the Globe It contained no
Free Oxygen The views of Koene, Berzelius, Mulder, Liebig,
Dumas, and Ch. Martins The Author's Observations and
Experiments Plants the first producers of Atmospheric Oxygen
Fixation of Carbon in the Earth's Strata Diminution of Carbonic
Acid in the Air The changeable Composition of the Atmosphere
Gradual increase of Oxygen, Pages 9-14
CHAPTER II.
Respiration in the Lowest Forms of Life Eremacausis on the
Earth, . Pages 15-17
CHAPTER III.
Plants are essentially Anaerobic Experiments by the Author
Primitive Atmosphere of the Earth Vegetation in this Primitive
Atmosphere and in other Gases, .... Pages 18-21
133489
vi TABLE OF CONTENTS.
CHAPTER IV
The Discoveries made by Priestley Mutual Dependency of Animals
and Plants The Author's Experiments with Unicellular Algae
The Author's Experiments with Convolvulus arvensis and other
Plants, Pages 22-24
CHAPTER Y.
Attempts to Define the Primitive Conditions of the Globe from the
Results of Modern Research The Dawn of Animal Life Effects
of the Gradual Increase of Atmospheric Oxygen, * Pages 25-31
PAKT II.
THE ATMOSPHERE OF OUR PRESENT PERIOD.
CHAPTER VI.
The Atmosphere is only a Mixture of Gases, not a Compound
Irrefragable Proof of this by Berzelius Its Changeable
Composition The Inert Nature of Nitrogen Ammonia and
Nitric Acid The Author's Experiments on their Mutual
Conversion The Unexplained Phenomenon of " Nitrifica-
tion" Its Universality Ammonia, like Carbonic Acid, a
Volcanic Product Nitrification due to the Oxidation of
Atmospheric Ammonia, Pages 32-37
CHAPTER VII.
Definition of the Atmosphere of the Present Day Transparency
Spectral Lines of Oxygen not given by the Sun's Atmos-
phere Observations and Experiments of Janssen, Piazzi-
Smyth, Langley, Dewar, and Faraday, . . . Pages 38-40
CHAPTER VIII.
Sulphur always present in the Atmosphere Characin, the Cause of the
Odour of Marshy Air Odours of the Air in Different Countries
The Odour of the Sea- Air Detected by the Author in Marine
Fossils of the Tertiary Period Odour of the Air after a Summer
Shower Observations regarding Ozone, . . . Pages 41-47
TABLE OF CONTENTS.
CHAPTER IX.
The Electric Phenomena of the Atmosphere The Author's Researches
and History of Electric Discoveries Phosphorescence of the Air
Vibratory Nature of the Lightning- flash, . . Pages 48-54
CHAPTER X.
An Unexplained Condition of the Atmosphere- Effects of Glare
Snow-blindness Hemeralopia and Amaurosis, . Pages 55-58
CHAPTER XI.
Solid Substances in the Atmosphere which fall to the Earth, or can
be detected in suspension in the Air The Author's first Discovery
of Iron Particles after the Meteor Stream of November 1866
Confirmed by other Observers His detection of Fossil Bacteria
in the Air, and of minute Crystals of Ice His Observation of
Bundles of Grass transported for hundreds of miles A Similar
Observation by Boussingault in Venezuela Presence of Salt and
Sulphate of Soda in the Air Gossamer Birds and Insects
Cosmic Dust Explosion of Meteors Periodic Plants Trans-
portation of Frogs, Stones, Volcanic Ash, etc. List of Extraneous
Substances Mode of collecting Bacteria Observations by
Pasteur, Miguel, and the Author, .... Pages 59-72
CHAPTER XII.
Air essential to Sound Mountain Air Dr. Viault's important Observa-
tion on Hsematosis Height of the Atmosphere Determination of
Altitude Effects on the Barometer and Thermometer Tempera-
ture at the Limits of the Atmosphere Hermite's recent Experi-
ments with small Captive Balloons Heights of Clouds
Determination of Water-vapour in the Air The Rain-band of the
Spectroscope, Pages 73-80
CHAPTER XIII. .
Air the only Gas that can be breathed Important "Work of the
late Wilson Phipson The Compressed-air Work of Daniel
Colladon Dr. Junod's Application of rarefied Air Air-bath
Establishments Disinfection Special Action of given Disin-
fectantsAbsence of Microbes in Pure Air, . . Pages 81-88
TABLE OF CONTENTS.
CHAPTER XI V.
Air of Inhabited Districts, of the Country, of the Sea-coast, and of the
Ocean Quantity of Carbon in the Air of a London Music Hall
Quantity of Carbon in the Atmosphere of the Earth Quantity
of Carbon in Organized Beings The New Gas "Argon" Forest
Air The Author's Observations in Waldeck, etc. The Influence
of Trees on the Air of Towns Influence of Forests on Rainfall
known to Columbus The Author's Explanation based on direct
Observation, . . . . . Pages 89-95
CHAPTER XV.
Cold Air more dangerous than hot Air The late Dr. Meisser's
Opinion Effects of Sojourn in the Tropics Temperature
Observations Altitude, Dryness, Humidity Carbonic Acid
in London Fogs Air over Stagnant Water Hydrocarbon
Gases in the Air of certain Localities The Air of Mines Air
of Bedrooms Air of Fermentation Air of Wells and Sewers
Air over active Volcanoes Air of the Mountains Effects of
Arsenic Air of Treeless Plains Air of the Arctic Regions, and
that near the Snow-line on Mountain-slopes Air of the Tropics
Air in Cholera Epidemics, Pages 96-105
CHAPTER XVI.
The Movements of the Atmosphere Barometer and Thermometer-
Cause of their Reverse Movements Expansion of Air Diurnal
Oscillations of the Atmosphere Fluctuations of the Electric
State of the Air Velocities of the Wind Cause of the Move-
ments of the Barometer English Weather Cyclones History
of Rotatory Storms Small Local Cyclones, . . Pages 106-115
CHAPTER XVII.
Absolute Weight of the Earth's Atmosphere Various Optical
Phenomena caused by the Air The greatest height Man has
reached on Foot The Snow-line and Region of Perpetual
Ice, . . Pages 116-120
TABLE OF CONTENTS.
CHAPTER XVIII.
The Formation of Clouds The Vesicular Theory The Present
Theory Cirrus Cloud Cumulus Cloud Stratus Cloud Nimbus
Cloud Colour of Cloud and Sky as an Indication of coming
Weather Cause of Electric Phenomena in Thunderstorms-
Formation of Snow and Hoar Frost Formation of Hail Curious
Phenomenon of the "Cloud-arch" First seen in England by
the Author In Sicily by the poet Goethe In the Arctic Regions
by Sabine, Pages 121-130
CHAPTER XIX.
Influence of the Gulf Stream on the State of the Atmosphere over
Europe and the Atlantic The Curve of Average Temperature and
its Teachings, Pages 131-134
CHAPTER XX.
Aerolites, or Stones from the Air "Thunderbolts" A Stroke of
Lightning A Fall of Meteoric Stones Belt of Meteorites round
the Earth Shooting-star Orbits, and Comets Old Opinion of the
Indefinite Extension of the Earth's Atmosphere, Pages 135-139
CHAPTER XXI.
The Organic Matter of the Atmosphere Effluvia, Miasma, Malaria,
etc., Pages 140-144
CHAPTER XXII.
State of the Atmosphere in any given Locality Immediate "Weather
Table for the British Isles and Northern Europe generally
Rainfall, %* . Pages 145-152
CHAPTER XXIII.
Fogs and Electricity Ronayne's Discovery Luminous Fogs
Prevention of Thunderstorms and Hail, . . Pages 153-157
TABLE OF CONTENTS.
CHAPTER XXIV.
Atmospheric Tides Magnetic Storms Sabine's Observations
Absorption of the Moon's Atmosphere, , . Pages 158-162
APPENDIX A. Account of an Experiment made with Convolvulus
arvensis Additional Notes, .... Pages 163-180
APPENDIX B., , . Pages 181-186
INDEX, Pages 187-194
PREFACE.
THIS little work is to a great extent the result of my
own observations, which have spread over a considerable
number of years ; but I have also availed myself largely
of the labours of others, in order to make it more com-
plete, and more useful ; for, as Benjamin Franklin said,
" Knowledge is only valuable in proportion as it can 'be
rendered useful to mankind"
I owe to my excellent father, to whom I dedicated
one of my former works, everything that could foster
the prosecution of travel and research, and, though I
have not taken full advantage of the excessive liberality
which he accorded to all his children, and cannot recall
his memory without acknowledging the immense debt
of gratitude with which it is associated, yet I trust that
my numerous writings will prove " useful to mankind "
for many years to come. However, his kindness and
foresight have enabled me to devote my life to scientific
pursuits, music, and literature, thus doing all he could
to make it a life of happiness and contentment in spite
of the sorrows and afflictions to which we are all subject
in this world, and I have striven to make it also a useful
life.
The present volume contains the results of the latest
xii PREFACE.
discoveries connected with the vast aerial ocean which
encircles the Earth ; the physical and chemical proper-
ties of the air ; its geological history as far as we can
trace it into the remotest ages of the past, and the
useful deductions that can be drawn from all these
facts.
My discovery of the origin of atmospheric oxygen,
made known in a series of papers published from 1893
to 1895 (Chemical News, London ; Comptes-rendus, Paris),
and the curious results of that discovery, induced me to
write this book, as so much interest is now taken in the
subject, in all parts of the world.
In the Philosophical Magazine for September and
October 1900 are two papers by Mr. John Stevenson,
M.A., communicated by Professor G. F. FitzGerald,
F.E.S., on the chemical and geological history of the
atmosphere, in which allusion is most indulgently made
to "Dr. Phipson's beautiful and interesting experiments/'
and in which Lord Kelvin's views are discussed. After
a very long and interesting discussion, Mr. Stevenson
confirms my opinion, declaring that " there was a time
when there was no free oxygen upon the Earth," and
also that " our present supply of free oxygen has been
all produced by the action of sunlight on vegetation/'
which is precisely what my experiments and observa-
tions have established.
CASA MIA, PUTNEY, LONDON.
OF THE
UNIVERSITY
OF
RESEARCHES ON
THE EARTH'S ATMOSPHERE.
INTRODUCTION.
The Science of the Atmosphere Its Numerous and Important
Applications Origin of Modern Chemistry The Theory of
Combustion History of the Chemical Composition of the
Air Discovery of the Barometer.
THE Science of the Atmosphere embraces not only the
whole domain of Meteorology the laws that determine
the distribution of temperature, the cause of winds and
cyclonic storms, the formation of fogs, clouds, dew, rain,
snow, and hail, luminous manifestations due to electri-
city, the phenomena of thunderstorms, ignis fatuus, and
fire-springs, phosphorescent glows, mirage, halos, aurora,
waterspouts, avalanches, and glacier movement, sand
and dust storms, etc. but, also, the realms of Physical
Geography, Geology, Chemistry, and Physiology the de-
structive action of the air upon the Earth's surface, by
its physical or mechanical action, and by its chemical
action ; the phenomena of respiration in Plants and
Animals, and its important consequences.
2 THE EARTH'S ATMOSPHERE.
Hence the study of the Atmosphere includes certain
branches of Medicine, antiseptic Surgery, and Hygiene,
establishing the laws of Climatology, by which the
practitioner is guided in the choice of residence for
invalids. It also enables him to effect the promotion
of health, and prevention of disease, by the detection
of impure, noxious air, and by applying the art of
rendering it wholesome.
Moreover, it embraces, also, certain practical portions
of Astronomy and Physics the laws of reflection, re-
fraction, interference, absorption, pressure, electric con-
dition, and magnetism.
It is, indeed, a vast field of inquiry, and one that is
practically inexhaustible; full of surprises inciting to
research, and leading to endless useful applications.
The Chemist and the Naturalist, the Astronomer and
the Physician, are alike interested in acquiring the most
perfect knowledge of the nature and phenomena of our
atmosphere, which knowledge forms the basis of the
greater portion of the sciences, and promotes the
prosperity of the human race.
The history of Chemistry the dawn of scientific
chemistry is intimately connected with this subject,
for modern Chemistry, with all its marvels of industry
and invention, may be said to date from the discovery
of oxygen. The advancement of the mechanical arts,
promoted by the discovery of the barometer and its
laws, is no less dependent upon an intimate acquaint-
ance with the properties of that vast aerial envelope
which encircles our globe, and is generally supposed
INTRODUCTION. 3
to extend to a height of some forty-five miles from the
Earth's surface.
The knowledge of the chemical composition of the
air is closely connected with the phenomenon of com-
bustion the most wonderful of all the phenomena of
Nature the theory of which forms the basis of modern
science, and governs its useful applications to the wants
of man. The ancients imagined a certain elementary
body called fire, which possessed the property of
devouring other bodies and converting them into itself.
According to this view, which is still held by our
domestic servants, when we set fire to a grate of coals
we bring a small portion of the element fire which
immediately begins to devour the coal and convert it
also into fire. Whatever part of the coal is not fit
to be this food is left behind in the form of ashes.
It was in 1665 that the celebrated English philosopher
Dr. Hooke (Micrographia, p. 103) first found that there
exists in the Atmosphere a certain substance which is
like that fixed in saltpetre. The French physician
Jean Eey held a somewhat similar opinion thirty-five
years previously. 1 In 1675 Hooke's opinion was adopted
and extended by Mayow, a young man of Oxford, who
published a pamphlet on the subject : De sal-nitro et
Spiritus nitro-aereo, which is now celebrated in the
annals of Science.
1 But about a century before this, the physician to Henri IV.,
Joseph Duchesne, called Quercitanus, a disciple of Paracelsus, who
was also the inventor of laudanum, and the discoverer of the gluten
of wheat flour, got the first glimpse of nitrogen. It was about the
year 1573 he said that "saltpetre contains an air which extinguishes
4 THE EARTH'S A TMOSPHERE.
Beccher, and his follower Stahl, came next with a
singular theory (phlogiston) that threw men's minds,
for a time, out of the correct line; and, strange to
say, this phlogistic theory was kept up by Priestley,
whose experiments on air, with those of Scheele and
Lavoisier, finally led to the foundation of modern
Chemistry.
I cannot in this work devote space to the purely
chemical investigations which gradually led us to a
knowledge of the various gases which compose the
Atmosphere. They must be sought for in treatises on
the history of Chemistry and Physics. I can only
say that, like all great discoveries, this knowledge was
derived from the labours of a large number of ingenious
men, among whom the most conspicuous are Van Helmont
(of Brussels), Jean Eey, Bayen, Hooke, Mayow, Hales,
Stahl, etc. To Priestley, Scheele, and Lavoisier is due
the discovery of oxygen ; Black (of Glasgow) discovered
the nature of carbonic acid. Nitrogen was actually
discovered in 1772 by Dr. Eutherford, then Professor
of Botany in Edinburgh (De Aere mephitico). Oxygen
was discovered about the same time by Priestley,
Scheele, and Lavoisier. In 1773 the latter gave us the
first analysis of the air (finding 27 to 28 per cent, of
oxygen, instead of 21). He began his researches in
the flame of a candle" (Clavis philosophorum in Theatrum chemicum,
iv. 1141, and Hoefer, Hist, de la Chimie, i. 471).
In very ancient times Hippocrates recognized in air his "pabulum
mice " (oxygen), and Democritus knew that it contained a vital
principle which fixed itself in the body during the act of breathing.
(See Aristotle, De Respiratione. )
INTRODUCTION. 5
1770, and finally announced in 1774 that "m every ease
of combustion oxygen combines with the burning body"
and from that moment the Science of Chemistry was
revolutionized, or, rather, created. Yet years elapsed
before he could make a single convert to his views!
The labours of Cavendish on hydrogen (1774), and
the speculations of James Watt and others, led to the
knowledge of the composition of water. " Ozone," or
allotropic oxygen, was discovered by Schcenbein of
Basle in 1845, and " argon" (or " allotropic nitrogen " ?)
by Eayleigh and Eamsay in 1894.
The ancients, with Aristotle, considered air to be
one of the " four elements " : fire, earth, air, and water.
It was also believed to have no weight.
In the early part of the seventeenth century an
obscure apothecary named Brun, living in the little
town of Bergerac, in France, noticed that when tin was
melted over a hot fire, it formed a kind of earth (or, as
we should now say, an oxide), and gained in weight. He
asked a medical man of his acquaintance, Dr. Jean
Key, who practised at the neighbouring village of
Bugue, in Perigord, how he would explain this, and
the doctor repeated the experiment several tiines.
Finally, in 1630, he published a now celebrated
pamphlet on the question, in which he declared that
tin, when heated, absorbed air and increased in weight.
This was a remarkable conclusion to arrive at, for
in those days air was supposed to have no weight.
More than a century later, when this pamphlet by
Jean Key was quite forgotten, another French observer,
6 THE EARTH'S ATMOSPHERE.
named Bayen, found that the same curious phenomenon
occurred with mercury, and he concluded that all metals
increased in weight when they were calcined. Finally,
the celebrated Lavoisier repeated this experiment with
mercury, and found that metals only absorb a portion
of the air, that portion now known as oxygen gas. He
thus made the first analysis of atmospheric air, as I
have already stated. 1
The weight of the air was discovered in the following
singular manner by the illustrious Galileo in 1640, and
his opinion was soon confirmed by Torricelli (his pupil)
and by the French philosopher Pascal.
Galileo carefully weighed a large vessel full of
ordinary air, and then the same vessel full of com-
pressed air. A difference of weight was noticed, and
this showed that the air was a body possessed of weight.
Not long afterwards, some well-sinkers at Florence
endeavoured to get water to rise more than 32 feet in
a pump, and failing to do so, they asked Galileo the
cause of this failure. In those days the rising of water
in a pump was said to be due to the fact that " nature
1 Nevertheless, it has now been ascertained that this experiment
is much older than has hitherto been supposed. It has been dis-
covered that Eck von Sulzbach, a man usually confounded with the
German alchemists of the latter part of the fifteenth century, was
really the first to notice that metals increase in weight when calcined.
His experiment was made with mercury, and with an amalgam of
silver, and he distinctly states that this increase in the weight of
the metal after calcination is due "to a spirit which fixes itself to
the body of the metal," and he also says that when the latter " is
distilled, this spirit is set free." Eck von Sulzbach made his second
experiment in 1489, so that these facts had been ascertained nearly
three hundred years before Lavoisier's experiment. (Compare Dr. F.
Hoefer, Hint, de la Chimie.)
INTRODUCTION. 7
abhors a vacuum"; and to explain the failure just
alluded to, Galileo is reported to have replied: "Yes,
nature abhors a vacuum, up to 32 feet, but not beyond."
This little incident set his pupil, Torricelli, thinking
over the problem. He imagined the rising of the water
in the pump was due to pressure (or weight) of the air,
and that this pressure was only equal to a column of 32
feet of water. He took a long tube of glass, filled it
with another liquid, mercury, turned it upside down, and
allowed its open end to rest on a bath of that metal.
He saw that the column of mercury stood at a height
of about 13 times less than that of the column of water
in the tube of the pump, and as mercury is about 13
times heavier than water, it was evident that the same
cause acted in both instances, and that cause was the
weight (or pressure) of the air.
Such being the case, the mercury in the glass tube
should stand lower on the summit of a high mountain
than in the valley, since it would have a less weight of
air over it. This was proved to be so, by Pascal and
Perrier, and so the barometer became at last one of the
most useful of physical instruments in the hands of the
meteorologist, the chemist, the physician, the sailor, the
farmer, and the engineer.
In bringing forward these modest contributions to so
vast a field of research and observation, I must solicit
a large amount of indulgence on the ]5art of my readers.
It is not my desire simply to reproduce here what is to
be found in standard works on Meteorology, but to give,
as well as I can, the results of my own personal obser-
8 THE EARTH'S ATMOSPHERE.
vations with as many new facts as possible, whilst I rely,
for the rest, on the useful and interesting nature of the
facts recorded.
I trust that my little work will thus help to diffuse
more exact knowledge with regard to the nature and
properties of atmospheric air, and so contribute to
promote, in many ways, the welfare of mankind.
The atmosphere, as we know it at the present day,
forms over the surface of the globe a vast layer of
invisible gas, extending to a great height, and charged
with emanations of all kinds, but chiefly of aqueous
vapour. When we subtract from it this aqueous vapour,
and a minute amount of carbonic acid, it is found,
in all parts of the world, to consist of a mixture of two
gases, nitrogen and oxygen, in the proportion of 79 of
the former to 21 of the latter. 1
1 The new gas called "Argon " recently discovered in small quantity
in the air by Lord Rayleigh and Prof. Ramsay, to which I make
reference in another part of this little work, appeared to be a
peculiar form of nitrogen, similar to what ozone is as regards oxygen.
I was the first to call attention to this circumstance in a note inserted
iu the Chemical News (1894), and my opinion has been since confirmed
by Prof. Berthelot of Paris (Comptes-rendus, March 1895). Prof.
Dewar seemed to be of the same opinion. It might also be a compound
of carbon and nitrogen, containing half as much carbon as cyanogen ;
such a compound would have the same specific gravity. But it is
impossible at the present time to speculate upon the real nature of
this new substance, as so very little is known about it. One hundred
volumes of atmospheric air contain less than one volume of " argon,"
and its name is due to its inert nature, its negative properties being
apparently greater than those of nitrogen itself. But whatever may
be its real nature, argon is only present to such an insignificant amount
(barely 1 per cent.} that it can exert no influence upon the general
properties of the air, nor, considering its inert character, upon animal
or vegetable life.
PART I.
THE EARTH'S ATMOSPHERE IN REMOTE
GEOLOGICAL PERIODS.
CHAPTEK I.
The Atmosphere in the earliest Epochs of the Globe It contained
no Free Oxygen The views of Koene, Berzelius, Mulder,
Liebig, Dumas, and Oh. Martins The Author's Observations
and Experiments Plants were the first producers of Atmos-
pheric Oxygen Fixation of Carbon in the Earth's Strata
Diminution of Carbonic Acid in the Air The changeable
Composition of the Atmosphere Gradual increase of Oxygen.
WATER and air the first a chemical compound, the
second a mixture only have been considered by
modern authors as the Residues left in primeval times
after the cooling of the Earth, residues of stupendous
chemical action, the formation of which rendered the
surface of the globe fit for the existence of organized
beings.
But, was the air in those primitive periods such as we
now know it ?
Everything points to the fact that the chemical con-
stitution of the atmosphere has varied in successive
ages, just as the various flora and fauna of the Earth
have changed.
io THE EARTH'S ATMOSPHERE.
The presence of certain combustible substances, such
as iron pyrites, copper pyrites, molybdenite, graphite,
etc., in the primitive rocks, long ago appeared to me to
prove that no free oxygen could have l)een present in the
atmosphere when these rocks were formed.
The late Prof. C. J. Koene, of the University of
Brussels, admitted that carbonic acid must have been
present in the ancient atmosphere of the globe in much
larger quantities than at present, especially during the
period of the coal flora, which notion appears to be
proved by the enormous residues of coal and anthracite,
as compared with the more recent deposits of lignite
and peat.
Four great names appear also in connection with this
subject : Jean Baptiste Dumas and Justus von Liebig on
the one hand, Berzelius and Mulder on the other. The
two former appear to have considered the chemical
composition of the atmosphere of our globe to be per-
manently fixed for an indefinite period, and, perhaps,
they admitted it always to have been so since the first
appearance of life upon the Earth, resting their views
on the fact that whilst plants give out oxygen and
absorb carbonic acid, animals absorb oxygen and reject
carbonic acid. Dumas and Liebig looked upon the
animal and vegetable kingdoms as indispensable one
to the other, and believed that their mutual action
upon the atmosphere would keep its composition
constant.
Charles Martins, a celebrated French naturalist, and
a contemporary x)f Dumas, criticized this compensation
EARLY GEOLOGICAL CHANGES. 11
theory, by pointing out the extremely minute quantity
of air which is affected by the respiration of plants and
animals, as compared with the vast bulk of oxygen in
the atmosphere. Making use of Dumas' own calcula-
tions, he shows that the atmosphere containing, say,
134,000 cubic measures of oxygen, the entire animal
world only consumes about 15 of these in an entire
century. Hence, he says, "The constant composition
of the air does not depend upon a pretended equilibrium
between the respiration of plants and animals , but upon
the fact that the quantity of oxygen consumed by
animals is out of all proportion to that contained in the
entire atmosphere." 1 Berzelius felt convinced that
oxygen must gradually diminish in the air, for, he
declared he knew of " no de-oxydizing process sufficiently
great and general to set at liberty all the oxygen which
combines every instant with combustible material." 2
The great Dutch chemist, Mulder, went still further ;
he insisted upon the enormous production of carbonic
acid by the respiration of animals, fermentation, volcanic
action, and human industry, and noted the constantly
increasing destruction of forests, those vast manufac-
tories of oxygen gas. He concluded that carbonic
acid must increase, and that oxygen has continued to
decrease since the first appearance of life upon the
Earth.
With regard to volcanic action, I myself have
calculated roughly, on the spot, the quantity of car-
1 Mtttoroloyie et Physique du Globe.
2 Traite de CMmie t vol i.
12 THE EARTH'S ATMOSPHERE.
bonic acid produced by a small chalybeate spring
near Neubau in the principality of Waldeck (Germany)
in the year 1865. It was somewhat over a pound
in weight per hour, or about half a hundredweight
in the twenty-four hours. And this is only one of
some thousands of similar springs scattered over the
surface of Europe alone.
Dr. Koene upheld a precisely contrary opinion to
those just mentioned: he admitted that the carbonic
acid and nitrogen of the atmosphere have never ceased
to diminish since the origin of living creatures, whilst
the relative amount of oxygen has gone on increasing in
proportion.
I shall show that oxygen has really increased ;
and, such being the case, nitrogen and carbonic acid
will, of course, appear to have diminished.
It seemed very evident to me that as there could
have been no free oxygen in the primitive atmosphere
of the Earth, the first living beings must have been
formed in an air composed of nitrogen, containing
some carbonic acid and vapour of water. They must
have been anaerobic, that is, capable of existing without
free oxygen', and it is interesting to note that some
fifteen years after Koene professed his theory, Pasteur
actually discovered anaerobic microbes and described
their functions in fermentation, etc.
It then struck me that plants were the first producers
of atmospheric oxygen, and that they have produced it
in constantly increasing quantities as ages rolled by,
iintil the air acquired the composition it now has ; and,
EARLY GEOLOGICAL CHANGES. 13
finally, I undertook a long series of experiments l with
the view of testing this theory.
By adopting the views of Lamarck and Geoffroy de
St. Hilaire, followed up by Darwin and his friends,
it would be easy to admit that these first producers of
free oxygen these anaerobic beings, consisting, in the
first instance, of the lower orders of plants such as the
Protococcus, or unicellular algae, on which I experi-
mented many years ago, and found that, weight for
height, they produced far more oxygen than the higher
plants would, in process of time, as the quantity of
oxygen in the air became greater, gradually become
more or less aerobic, and finally completely so. ...
Ferdinand Hoefer's opinion that plants first appeared
is stated in the following lines :
" Starting from the theoretical view of the gradation
of organized beings, and looking upon vegetable life as
a necessary condition of animal life, the former must,
consequently, have appeared before the latter." 2
Alexander von Humboldt made a rather weak
attempt to disprove this by alluding to the fact that
the Esquimaux live almost exclusively on fish and
cetacea.
An immense quantity of carbon is fixed in the
Earth by the remains of plants and animals, and
never returns to the air. Nitrogen ,is also supposed
to be extracted from the atmosphere to form nitrates
1 Comptes-rendus de I'Acad. des Sc., Paris, Aout 1893 and 1895,
and Chemical News, London, 1893 and 1894.
2 Histoire de la Botanique.
14 THE EARTH'S ATMOSPHERE.
and ammonia ; but I shall show that this is not the
case.
Oxygen alone remains in relatively larger and larger
proportions ; it has increased since the first living beings
appeared, and its present maximum coincides with the
maximum development of the central nervous and brain
tissue of the animal world.
As for carbonic acid, for the last half century chemists
have noted it as only 6, 5, and 4 parts on 10,000 parts
(volumes) of air. The latest determinations by Eeiset
(a very careful chemist, pupil of Boussingault, and one
of the editors of Millon's well-known Annuaire), made at
a country place, many miles from Paris, gave only 3
volumes of carbonic acid on 10,000 volumes of air in
1889, and he could not get a fraction more. Pelouze,
master of the Mint at Paris, who was one of the most
expert chemists of modern times, held the opinion that
the atmosphere might be undergoing very slight variations
which will only become appreciable to analysis after a
great number of years. Baudrimont, and other eminent
chemists have held similar views, admitting that the so-
called fixity of composition is only apparent, not real.
CHAPTER II.
Respiration in the Lowest Forms of Life Eremacausis
on the Earth.
ANATOMY and physiology cannot teach us how respira-
tion is effected in the lowest creatures in the scale of
life, those which are supposed to have been the first
produced. All vestiges of a respiratory organ are
absent, unless it be the cell wall or outer envelope
that breathes.
Until my recent experiments were made (which,
however, were preceded in another direction by those
of Pasteur, when he discovered the anaerobic ferments),
no one could say whether these beings require free
oxygen or not ; though this could be proved for higher
organisms, such as fish and tadpoles, which live in
water. I found that the microscopic unicellular algae,
Protococcus pluvialis, P. palustris, etc., carry on their
respiratory functions much as the higher organized
plants do, but with more energy. In such animals as
ffolothuria tululosa, the functions of respiration is little,
if at all, separated from that of the intestine : water is
sucked in, three times a minute, and remains about
twenty seconds in the animal's body.
1 6 THE EARTH'S ATMOSPHERE.
It is not yet known with certainty whether these
lower forms of life may be able to derive oxygen from
water, or carbonic acid, or both. But it is evident that
oxygen is essential both for plants and animals, how-
ever low in the scale ; in fact, that oxygen arid life seem
to be synonymous terms in this respect ; only, we must
distinguish between oxygen in combination, and the free
oxygen of the atmosphere.
Koene's ingenious theory to which I have alluded is
based upon the incomplete eremacausis of organic matter
which is confided to the earth, and protected from the
action of the air, by which means enormous quantities of
carbon have always been, and are still being, slowly
subtracted from the atmosphere. He did not believe
that this element can be supplied from without from
cosmic space and it thus disappears for ever from our
atmosphere.
But is this eremacausis, or slow combustion, really so
incomplete ? Is not carbonic acid returning in immense
quantities to the atmosphere, not only by the respira-
tion of animals and volcanic action, but by the agency of
man himself ? In times, perhaps not so very far distant,
will not the whole of those vast deposits of coal and
lignite, formerly taken from the air, return to the atmos-
phere again as carbonic acid ? And if forests continue
to be constantly annihilated, as Mulder remarked, to
make room for clay and stone buildings, will not car-
bonic acid increase, until it once more predominates, as
it is supposed to have done in primitive times?
It seems evident to me that vitality, nervous power,
RESPIRA TIONEREMA CA US IS. 1 7
and atmospheric oxygen have increased together, from
the earliest ages of the globe, and that the history of
this increase can be read in the records of the Earth's
strata.
Although, as will be seen presently, my researches
bear out this theory of the increase of oxygen in the
atmosphere, it presents, at first sight, a curious para-
doxical aspect: oxygen is admitted to be the product
of life, whilst it is the condition of life, and its final
predominance in the atmosphere will, perhaps, be the
cause of universal death. Certainly this appears highly
paradoxical ; and it may be questioned whether the
solution of such problems is not beyond the powers of
Science, like all those which touch upon creation.
But, as I have already remarked, we must distinguish
between oxygen, and/m oxygen in the atmosphere.
CHAPTEE III.
Plants are essentially Anaerobic Experiments by the Author
Primitive Atmosphere of the Earth Vegetation in this
Primitive Atmosphere and in other Gases.
ADMITTING that no free oxygen could have existed in the
atmosphere when life first appeared upon our globe,
and that this atmosphere must then have consisted of
nitrogen, containing more or less carbonic acid, and
vapour of water, it follows that atmospheric oxygen must
originally have been derived from the vital functions of
inferior plants such as the unicellular algae, which were
the first created beings, having the power, under the
mysterious influence of the solar rays, of separating it
from its compounds, carbonic acid and water. Granting
that the ancient cryptogamic plants of the Coal flora
period, for instance, could thrive at higher temperatures,
and in an atmosphere far richer in carbonic acid than
that of our own day, it became very interesting to ascer-
tain to what extent our modern plants can vegetate
under similar circumstances.
It was in making experiments to this effect I dis-
covered that all plants are essentially anaerobic. I
have caused them to vegetate in carbonic acid, in
ANAEROBIOSIS. 19
hydrogen, and in nitrogen, as well as in a mixture of
nitrogen, carbonic acid, and vapour of water repre-
sentative of the "primitive atmosphere" at the time
life first appeared.
I was thus gradually led to conclude that the primitive
atmosphere of the Earth was nitrogen, into which
volcanic action poured more or less carbonic acid and
vapour, and that after vegetable life appeared, free oxygen
made its appearance in the air, and has increased in
quantity from those primitive times to the present day.
I had noticed many years ago that certain plants
(willow, lilac, etc.) did not thrive in pure carbonic acid,
and I concluded that the diminished quantity of this
gas now existing in our atmosphere was the condition
that suited them best.
In experiments carried out more recently, I have
placed various other plants, such as Poa, Agrostis,
Myosotis, Antirrhinum, and Convolvulus in an atmos-
phere composed of pure carbonic acid, and in one
composed of air with about a hundred times more of
this gas than exists in our atmosphere at the present
day. All other conditions of vegetation were normal :
there was ample water, mineral elements, and an
appropriate temperature ranging from 59 to 70 Fahr.,
during the whole course of the observations.
It was not long before I found that my plants could
exist for many days, or even weeks, in an atmosphere
of pure carbonic acid, but they did not thrive ; cell
formation became slower and slower, in spite of a
constant good light.
20 THE EARTH'S A TMOSPHERE.
In an atmosphere that contained so much carbonic
acid that an animal exposed to it would perish in a
few minutes, all my plants lived for many weeks, and
appeared healthy.
In an atmosphere containing one hundred times as
much carbonic acid as in the natural state of the air
in our day, my plants flourished remarkably well for
the whole time that the experiment lasted a month,
or six weeks.
It was thus rendered highly probable that in former
geological periods there existed plants which could
flourish in an atmosphere excessively rich in carbonic
acid, and that the quantity of that gas in the air has
really decreased from those times to the present day ;
the loss being represented by the vast deposits of peat,
lignite, coal, and anthracite found in the strata of the
Earth.
I also made some experiments in an atmosphere of
pure hydrogen, out of curiosity to see what would
happen when plants were placed in such a medium
a gas which many have looked upon as the vapour of
a metal all other conditions remaining normal, namely,
water charged with carbonic acid, and containing the
necessary mineral ingredients, and a steady source of
daylight.
The plants I placed in this atmosphere of pure
hydrogen were Convolvulus arvensis (a plant which
is very convenient for observation of this kind), and
a small specimen of Antirrhinum majus. For the
first few days nothing peculiar was noticed. From
ANAEROBIOSIS. 21
the 27th May to the end of the month a slight bleach-
ing of the leaves only was apparent, but by 3rd June
a singular phenomenon occurred: the volume of gas
began to diminish, and in the course of another month
the atmosphere of hydrogen in which the Convolvulus
vegetated was absorbed to the extent of about 80 per
cent.
The residue, 20 per cent., was found not to be
hydrogen; so it may safely be said that the whole of
the hydrogen had disappeared, the plant remaining
perfectly healthy. I can only explain this phenomenon
by assuming that the nascent oxygen emitted by the
leaves burns up the hydrogen, and converts it into
water. The same thing occurred with the Antirrhinum,
but the action was slower. In both cases the leaves
were slightly bleached, and as the water charged with
carbonic acid rose in the apparatus and covered them,
they became green again.
In all these experiments the plants were exposed to
the constant light of a northern sky, such as artists
use for painting.
The rapidity of cell formation in an atmosphere of
hydrogen gas, observed in the case of Convolvulus
arvensis, was highly remarkable.
CHAPTEE IV.
The Discoveries made by Priestley Mutual Dependency of
Animals and Plants The Author's Experiments with Uni-
cellular Algce The Author's Experiments with Convolvulus
arvensis and other Plants.
IN 1791, when Dr. Priestley's house was burnt by
the Birmingham mob, and he saved his life by escap-
ing in my grandfather's carriage, a considerable amount
of valuable silver plate, etc., was carried off, but none
of the still more valuable MSS., the results of years
of labour. These were destroyed, together with the
entire library and laboratory. It is therefore impossible
to say how far he may have pushed his investigations
with regard to the mutual dependency of plants and
animals after discovering, some twenty years previously,
that " a sprig of mint vegetating for a few days in an
air vitiated by a burning candle restored the purity
of that air sufficiently to allow the candle to burn in
it again."
In the seventh edition of the Introduction to Botany,
by Sir J. E. Smith, edited by William Hooker (1803,
page 104), the author, alluding to the absorption of
carbonic acid by plants, and its replacement, volume
OXYGEN AND ITS DEVELOPMENT. 23
for volume, by oxygen gas, says: "This beautiful
discovery, for the main principles of which we are
indebted to the celebrated Dr. Priestley, shows a mutual
dependence of the animal and vegetable kingdoms on each
other, which had never been suspected before his time."
It is not probable, however, that Priestley could have
made much further advance in this direction, owing
to the backward state of chemistry in his day, and to
his zeal for political and religious discussions. It was
reserved for the persevering researches of the Swiss
chemist, Theodore de Saussure, and to the splendid
genius of Justus von Liebig, to demonstrate this mutual
dependency in all its striking realities.
Yet it is greater than even Liebig imagined !
After having found that minute microscopic plants,
such as .the Protococcus pluvialis and P. palustris (uni-
cellular algae), could be easily transformed, so to speak,
into manufacturers of oxygen gas, 1 and that they
produced it more rapidly than do the higher plants
of our epoch, I placed several kinds of the latter in
pure carbonic acid, and found that it did not kill them
at once, as it would kill an animal, but that they lived
in it for some time, though they did not prosper. In
an atmosphere of hydrogen they lived and prospered ;
but the hydrogen gas was slowly absorbed, as we have
already seen, until it had all disappeared. In the next
place I exposed my plants to an atmosphere of pure
1 Phipson, "Production of Oxygen by Protococcus pluvialis" (with
figure of the apparatus), Chemical News, 1883 ; " The free Oxygen of
the Atmosphere," ibid., November 1894.
24 THE EARTH'S ATMOSPHERE.
nitrogen, and to what I may term a " primitive atmos-
phere," consisting chiefly of nitrogen, with some carbonic
acid and vapour of water, and I found that, in both
cases, vegetation was remarkably healthy, and even
luxuriant, for a lengthened period.
A small plant of Convolvulus arvensis, having its roots
in the soil, or in water containing ample carbonic acid
and mineral ingredients, vegetated in an atmosphere of
pure nitrogen for ten days (22nd June to 2nd July).
I then let in carbonic acid, an equal volume, which in
twenty-four hours was absorbed by the water to the
extent of about one-half ; so that the artificial atmos-
phere, on the next day, consisted of about three volumes
of nitrogen and one volume of carbonic acid. In this
atmosphere the vegetation became truly luxuriant from
the 2nd to the 15th July, and would doubtless have con-
jfcinued much longer had not the experiment been stopped
in order to analyse the gas, and because the plant had
reached the summit of the apparatus, and was pressing
against the glass.
In another similar experiment the residual gas, after
fourteen weeks of vegetation, was found to be richer in
oxygen than ordinary atmospheric air. 1
In these experiments the plant appears to absorb
carbonic acid by the roots (as well as the leaves), whilst
it evolves oxygen by the leaves ; so that, after awhile,
the nitrogen atmosphere contains a certain quantity of
oxygen and, in time, approaches, or even surpasses, the
composition of ordinary air.
1 See APPENDIX for fuller account of this experiment.
CHAPTER V.
' . ij '
Attempts to Define the Primitive Conditions of the Globe from the
Results of Modern Research The Dawn of Animal Life
Effects of the Gradual Increase of Atmospheric Oxygen.
Now, if I endeavour in thought to go back to the primi-
tive ages of the globe, I find that there was probably a
period at which the heat was so intense that no com-
pounds could exist. The matter of the Earth then
existed in the state of free elements, or, according to
my own theory, 1 in the state of atoms all identical.
As the temperature decreased, compounds of all kinds
were formed according to the laws of affinity; and,
finally, there remained, surrounding the solidified sur-
face of the Earth, an atmosphere of nitrogen a substance
which is known to have no tendency to combine directly
with other substances.
That there was no free oxygen in this primitive atmos-
phere is evident from t the presence of various oxidizable
substances in the primitive rocks of our globe. It is
into this primitive atmosphere of nitrogen that plants have
poured oxygen, year after year, for countless myriads of
1 Phipson, Outlines of a New Atomic Theory, fourth edition, London,
1886. See APPENDIX.
26 THE EARTH'S ATMOSPHERE.
ages, until it has attained the composition which it has at
the present day.
In remote geological periods it may have contained
much more carbonic acid than at present ; but carbonic
acid could never have predominated, from the fact that
it would have been absorbed by the waters of the oceans,
lakes, and rivers, and from my experiments, which show
that even our modern plants can live in an atmosphere
of nitrogen, but do not thrive in pure carbonic acid.
I was thus led to the conclusion that the original
atmosphere of our globe consisted of nitrogen alone, and
that the oxygen of the atmosphere is the product of vege-
table life (which must necessarily have preceded animal
life). 1 The production of oxygen by the minute uni-
cellular algae exposed to the light of the sun is a symbol
of what took place in the primitive ages of the Earth.
Carbonic acid must be looked upon as a volcanic pro-
duct, extensively diffused through the Earth's strata,
and into the atmosphere and waters. The primitive
atmosphere of nitrogen would derive abundance of
carbonic acid and vapour from volcanic action, which
continued to be very intense long after the Coal flora
period, and appears to have gradually diminished from
that period to the present time, though it is still very
active in many parts of the globe.
Now let me say a few words on the dawn of animal life.
1 It might be objected that the plants which first produced atmos-
pheric oxygen must already have contained oxygen as part of their
tissues. Whence did they derive that oxygen ? But I have never said
that plants were the creators of oxygen, only that they were the means
by which Nature has placed free oxygen in the atmosphere of the Earlh.
OXYGEN, PLANTS AND ANIMALS. 27
I have endeavoured to show that in the earliest ages
of the Earth, when life first made its appearance, plants
(anaerdbics) must have been formed long before animals
(aerobics), since free oxygen was absent from the primi-
tive atmosphere. My experiments on vegetation in
hydrogen show that free hydrogen could not have
existed in this primitive atmosphere any more than it
can exist for any length of time in the atmospheric air
of our days, without becoming oxidized, and converted
into water.
Nitrogen alone, on account of its inert nature, could
have formed the Earth's atmosphere in the earliest ages
of our planet's history ; and previous to the advent of
life, this primitive atmosphere was charged with carbonic
acid and vapour of water by volcanic action, such as we
see manifested to a considerable extent at the present
time.
Hence, the earlier vegetative life of the globe de-
veloped in an atmosphere devoid of free oxygen, con-
sisting of nitrogen gas, with a certain admixture of
carbonic acid and vapour, the whole of the oxygen now
present in the air being due entirely to vegetation
extending over immense periods of time.
As the ancient plants were evidently anaerobic, it
was very interesting to ascertain whether the plants of
our present epoch were essentially of the same nature ;
and my experiments have shown me that they are ; also,
that they must have preceded animal life.
Animal life has resulted naturally from the gradual
transformation of anaerobic cells into aerobic cells, as a
28 THE EARTH'S ATMOSPHERE.
consequence of the changing conditions, that is, the oxygen
constantly poured into the air by vegetation.
At what precise geological period oxygen became
present in sufficient quantity to allow of animal life
might appear an extremely interesting problem to solve ;
but no such period witt ever be determined, because the
change must have been exceedingly gradual, and the
study of the lower forms of plant and animal life show
us that there is no hard and fast line between the two
kingdoms. There is no such thing to be discovered as
" the first vestiges of animal life."
As the oxygen evolved from the anaerobic cells
became slowly and gradually a greater factor in the
composition of the air, these cells had to accustom
themselves to it, until some became more or less aerobic,
and, finally, entirely so, and by their vital functions
actually supplied carbonic acid to the air instead of
oxygen.
Between green plants, beings which are essentially
anaerobic, and the more perfect animals, beings which
are just as essentially aerobic, there exists a vast inter-
mediate class which presents, more or less, the character-
istics of both ; such are the various organized ferments,
fungi and bacteria, etc., which represent the gradual
transformation of the anaerobic cell into the aerobic
cell, under the influence of the gradual change of
medium; that is, the constantly-increasing amount of
free oxygen in the atmosphere since the earlier geological
ages. In the common yeast-fungus we have a familiar
example of a cell which has undergone the influence of
OXYGEN, PLANTS AND ANIMALS. 29
the change referred to a cell which combines the plant
and animal properties, and secretes carbonic acid in the
conditions in which the green unicellular algae secrete
oxygen. In the latter case, the oxygen evolved is
separated from carbonic acid, and the carbon retained
by the plant ; in the former, carbonic acid is secreted
by the yeast cell just as in the higher animals; the
function is far more complicated, and requires a special
nutriment, and the existence is rapid and short.
The French naturalist, A. Dissard, has recently
published a paper, La transpiration et la respiration chez
les Batraciens (Comptes-rendus, Paris), which gives us
some idea how the change in the medium determines a
change of function, such as I allude to here. Kespira-
tion is more active with aerial batrachians than in
the aquatic species; exactly the reverse occurs for
transpiration.
In one of my experiments, in which a Convolvulus grew
for fourteen weeks (25th July to 30th October 1893),
the confined " primitive atmosphere " lost all its carbonic
acid, and the atmosphere at the end of the experiment
was richer in oxygen than is ordinary atmospheric air.
This shows what would happen to the Earth's atmos-
phere if there were an excessive supply of carbonic acid,
and vegetation did not deteriorate : the oxygen of the air
would increase year by year.
In the present state of things ttiere is a kind of
equilibrium apparent (not real), as during the last fifty
or sixty years no great excess of oxygen gas has been
detected by chemical analysis of the air, in whatever
30 THE EARTH'S ATMOSPHERE.
locality, or at whatever elevation over the sea it may
happen to have been collected. But what are fifty or
sixty years compared to the thousands of centuries by
which Nature counts her periods !
At Palermo it has been found that there is a slight
diminution of oxygen in the air whilst the Sirocco
blows. At Dresden, Professor Ficinus found a slight
variation according to the direction of the wind ; with
the west and south winds the quantity of oxygen
was always the highest. Something similar has been
noted with regard to air analyzed at Copenhagen, at
Helsingfors, at Guadaloupe, and of the air over the
North Sea. In spite of the utmost care in the analyses,
there were considerable differences in the amount of
oxygen found in all these cases. The air of Calcutta
during an outbreak of Cholera in 1845 yielded only
20'35 of oxygen (instead of 21), and 0'13 of carbonic
acid (instead of 0*04 or 0'05); and there are other
examples tending to show that the volumetric proportion
of 79 of nitrogen to 21 of oxygen is anything but a
fixed quantity. However, I have little faith in the
accuracy of these analyses ; and they must always be
reduced to C. and 30 inches barometer, which some
of them were not. In former years also, analysis of the
air was very frequently performed with phosphorus,
which gives extremely erroneous results unless special
precautions are taken.
In concluding the first part of this little work, we
cannot help observing that it is a striking reflection
when we consider that all the superiority of Man upon
OXYGEN, PLANTS AND ANIMALS. 31
this Earth depends upon fire, and that this fire is got
by oxygen, originally the product of the minute cells of
such humble plants as the microscopic unicellular algae,
vegetating under the mysterious agency of the Sun's
rays !
Light, indeed, may be said to be the origin of Life.
PART II.
THE ATMOSPHEEE OF OTJR PRESENT PEEIOD.
CHAPTER VI.
The Atmosphere is only a Mixture of Gases, not a Compound
Irrefragable Proof of this by Berzelius Its Changeable
Composition The Inert Nature of Nitrogen Ammonia
and Nitric Acid The Author's Experiments on their Mutual
Conversion The Unexplained Phenomenon of " Nitrifica-
tion" Its Universality Ammonia, like Carbonic Acid, a
Volcanic Product Nitrification due to the Oxidation of
Atmospheric Ammonia.
THE ancients looked upon the air as an element, and
I have shown that in the earliest ages of the globe it
was really so, for the atmosphere must then have
consisted of nitrogen only, and the free oxygen which
now forms part of the air we breathe, and without
which animal life is impossible, is entirely the product
of plant life extending over countless ages.
At the present time the atmosphere of the Earth,
in accordance with the foregoing considerations, is not
a compound, but a mixture of nitrogen and oxygen.
This was amply proved by the great Swedish chemist,
Berzelius, in his TraiU de Chimie (vol. i, p. 88, Belgian
OF THF:
UNIVERSITY
CONSTITUENTS OF THE ATMOSPHERE. OF 33
edition). Here is the passage in question ;
an important page in the history of science :
" Some naturalists have endeavoured to prove that
atmospheric air is an oxide of nitrogen. They base
their opinion chiefly on the fact that it is almost
exactly composed of four parts of nitrogen for one part
of oxygen, and that consequently it contains half as
much oxygen as nitric oxide gas. But if such were
the case, atmospheric air would offer to us the first
known example of a simple mixture having absolutely
the same properties as a chemical combination of the
same elements. For, in fact, an artificial mixture of
four parts of nitrogen and one of oxygen does not differ
from atmospheric air as to its physical and chemical
properties ; and what proves clearly that this mixture
is not a chemical compound is that no change in the
volume, nor of the temperature, takes place at the
moment the mixture is made. As, moreover, nitric
oxide gas is converted into nitrous acid when it
comes in contact with the air, it would result from
this opinion that an oxide of a higher degree, and
containing more oxygen, would possess the property
of reducing, without the co-operation of any third
body, an inferior degree of oxidation of the same
radicle, a case of which Chemistry offers no example.
Atmospheric air is, therefore, not a gaseous oxide of
nitrogen, but a simple mixture of nitrogen and oxygen
gases"
This settled the question for ever. And it was this
knowledge that our atmosphere is but a mixture, and
c
34 THE EARTH'S ATMOSPHERE.
not a compound, that has hitherto been an enigma in
Science, ever since the fact was discovered.
The more so that, neglecting to take into account
that " time is the creation of Man," it was judged from
a few analyses extending over a small number of years,
that the proportion of oxygen and nitrogen in the air
is invariable, and never has varied !
If only a mixture, and not a definite compound, how
is it, people ask, that its composition remains fixed ?
how is it that it shows the same quantities of oxygen
and nitrogen in whatever part of the Earth it is
analyzed, and at whatever height above the sea the
sample of air is taken ?
All this is explained, of course, by allusion to the law
of diffusion of gases. But it must not be forgotten that
changes in nature are very gradual, and very slow in com-
parison with the short, rapid span of Man's existence.
Several eminent men have already supposed, as we
have seen, that the composition of the atmosphere is
changeable. A slight practical glimpse of such a fact
occurred in the analyses made by Levy, a Danish
chemist, of air lying over the waters of the ocean
between Havre and Copenhagen; and I myself made
similar experiments with air taken at the surface of
the sea many miles from the coast of Flanders. Such
air contains somewhat less oxygen than that which is
collected on the land. This was explained by the fact
that oxygen gas is slightly more soluble in water than
is nitrogen ; and free oxygen is required for the respira-
tion of aquatic animals.
CONSTITUENTS OF THE A TMOSPHERE. 35
The same slight deficiency of oxygen should be found
in air lying over vast inland lakes ; for, the air ex-
tracted from fresh water, by boiling, contains 33 per
cent, of oxygen, instead of 21 (the proportion in atmos-
pheric air). But the constant motion of the air keeps
its composition very similar in all its parts, like that
of a solution of sugar constantly stirred by a glass rod.
Then, the nature of Nitrogen formed a subject of
uncertainty. Here is a substance which, combined
with oxygen, forms one of the strongest acids, and,
combined with hydrogen, one of the most powerful
alkalies.
Now, other substances combine both with oxygen
and hydrogen, but, as Berzelius remarks, always to
form acids (Traite* de Chimie, vol. i. p. 146, Belgian
edition). It is true that phosphorus and arsenic imitate
nitrogen in this respect, but they form nothing com-
parable for energy with nitric acid and ammonia.
Berzelius did not perceive that nitrogen is essentially
neutral, or inert ; that is why it must have formed the
original atmosphere of the Earth. Hence, in nitric acid
all the electro-negative properties of oxygen are ap-
parent, and in ammonia all the electro-positive pro-
perties of hydrogen. In neither case does the neutral
nitrogen interfere. It is the only element of this ab-
solutely neutral nature. Hence, also, all the compounds
of nitrogen have to be formed indirectly, by round-
about processes.
We have no facts in the whole range of Chemistry
more striking than that the two substances ammonia
36 THE EARTH'S ATMOSPHERE.
and nitric acid, so essentially opposite in character, are
readily convertible one into the other. I have found,
for instance, that ammonia oxidized in the cold by
a solution of permanganate of potash, forms nitrite and
nitrate of potash ; and it has long been known that
when zinc, or tin, is dissolved in nitric acid ammonia
is found in the solution.
For many years it has been supposed that the nitrogen
of the atmosphere plays an important part in the process
of "nitrification," and many theories have been put
forth to explain it porous bodies, catalysis, electricity,
bacteria, etc. but we may safely assert that it is still
unexplained.
In several experiments I made, years ago, with the
view of thus forming saltpetre artificially, / never
obtained any nitrates unless some ammonia-yielding sub-
stance was present, and I look upon the phenomenon of
nitrification as due to the slow oxidation of ammonia in
nature. The process is universal ; it occurs constantly,
everywhere ; but it is only in those parts of the globe
where rain is scarce that the resultant nitrates are
easily discovered, or where they effloresce from the soil.
In all other places they are washed away by the rain as
fast as they are produced, and find their way into the
rivers.
Now, ammonia is not only a volcanic product (like
carbonic acid), but an organic residue a secretion that
has found its way into the superficial strata of the
Earth ever since life appeared upon the globe. Ammonia
is a poison to plants, but nitrates are absorbed by all
CONSTITUENTS OF THE ATMOSPHERE. 37
vegetables, and I have convinced myself that ammonia
is converted into nitric acid before its nitrogen can enter
the plant, and that ammonia will kill the plant unless
this conversion can take place.
In the earlier ages of the globe, there could have been
no nitric acid, nor even ammonia ; but when the Earth
had cooled sufficiently long before life appeared
ammonia could exist in the volcanic products as it
does at the present day, but no nitric acid. 1 Later
still, nitric acid formed from ammonia (" nitrification ")
was produced, and plant-life became possible.
Ammonia, like carbonic acid, must therefore be
looked upon as a volcanic product ; and, when organized
beings decay, their nitrogen and carbon return to
nature as ammonia and carbonic acid.
Hence it is evident that atmospheric nitrogen takes
no part in the important process of nitrification, unless
it be that which is directly converted into nitric acid
during combustion of various substances in the air, or
by the lightning flash, and which may, after all, be due
to the ammonia that is always present in the air.
1 Ammonia has recently been found in the mineral Apophyllite, to
the extent of 0'03 to 0*5 per cent.
CHAPTEE VII.
Definition of the Atmosphere of the Present Day Transparency
Spectral Lines of Oxygen not given by the Sun's Atmos-
phere Observations and Experiments of Janssen, Piazzi-
Smyth, Langley, Dewar, and Faraday.
A POPULAR writer on Science has said : " The Earth we
inhabit is surrounded by an atmosphere of air, the
height of which is known to be at least forty-five miles.
It presses upon the Earth with a weight equal, at the
level of the sea, to about 15 Ibs. on every square inch of
surface. As we ascend high mountains, this weight
becomes less; as we go down into deep mines, it
becomes sensibly greater. We breathe this atmos-
pheric air, and without it we could not live many
moments. It floats around the Earth, being in per-
petual motion; and according to the swiftness with
which it moves, it produces gentle breezes, high winds,
or terrible tornadoes."
It is hardly possible to give, in fewer words, a
general definition of the Earth's atmosphere.
The transparency of the air, cceteris paribus, must
increase with the height above the Sea; but this
increased transparency shows itself in a very remark-
OBSERVATIONS. 39
able manner : the absence of some of the spectral lines
of oxygen, when the Sun is viewed from the summit of
Mont Blanc, has recently led the well-known French
astronomer, M. Janssen, to the conclusion that there is
probably no oxygen in the Sun's atmosphere.
My friend, Piazzi-Smyth, when Astronomer-Eoyal
for Scotland, was the first, many years ago, to carry an
astronomical telescope into the higher regions of the
atmosphere. With the view of avoiding the influence
of a dense layer of air, he took his instrument to the
top of the Peak of Teneriffe, where he made some
very interesting physical and astronomical observations.
These were, on his return to England, the occasion of
the publication of one of the most curious and
delightful books in our language (An Astronomer's
Experiment, etc.).
Since then, we have had a number of similar observa-
tions by Professor S. P. Langley, of Washington, which
have been carried out on the heights of the Californian
mountains, in one of the districts of the globe where
the atmosphere is extremely pure, and where he was
provided with one of the finest telescopes ever con-
structed. Under these most advantageous circum-
stances, Mr. Langley made observations on the heat
and colour of the sun and planets, the distribution of
the lines of the spectrum, the constitution of the solar
surface, the distribution of light and heat upon the
disc, the extent of the absorbing power of the Sun's
atmosphere, and that of our Earth, the temperature of
the Sun (which he fixes at some degrees higher than
40 THE EARTH'S ATMOSPHERE.
the fusion point of platinum), and many other important
researches, to which we need not here refer.
I should mention, also, the recent curious experi-
ments made by Professor Dewar, of the Eoyal Institu-
tion, on the liquefaction of oxygen gas and of atmospheric
air, accomplished by the application of intense cold and
pressure. In following up the experiments of Pictet
and others in this direction, our English professor has
gone a step further (Chemical News, 19th January 1894),
and his results have excited general interest. Berzelius
recognized that the true colour of atmospheric air is blue,
and the liquefied oxygen of Professor Dewar is likewise
blue. It possesses the most singular properties, being
without any action upon such inflammable metals as
potassium and sodium, which shows what an enormous
influence is exerted by temperature on chemical action.
This became evident, years ago, in experiments by the
celebrated Faraday 1 as regards liquefied gases. He
found that liquefied protoxide of nitrogen would not act
on potassium, nor liquefied chlorine on antimony, etc.
1 See Dumas, filoge de Faraday, p. 12.
CHAPTER VIII.
Sulphur always present in the Atmosphere Characin, the Cause
of the Odour of Marshy Air Odours of the Air in Different
Countries The Odour of the Sea-Air Detected by the
Author in Marine Fossils of the Tertiary Period Odour of
the Air after a Summer Shower Observations regarding
Ozone.
PUKE air is odourless and tasteless, except when ozone
is strongly developed, or when lightning strikes an
object on the surface of the Earth. In the latter case,
an odour of sulphurous acid is distinctly noticed, as I
have had occasion to observe more than once. On one
of these occasions, in Paris in 1858, it affected the
neighbourhood for a considerable distance around, and
penetrated all the houses.
This odour of sulphurous acid is likewise perceived
at sea when a ship is struck by lightning. It proves
the existence of a certain amount of sulphur, or some
compound of sulphur, in the air, even hundreds of miles
from land.
That sulphur, in some form, is a constant constituent
of the Earth's atmosphere appears to be becoming less
doubtful every day. In the early part of this century
a writer in the Archiven der Pharmacie, named Dulk,
42 THE EARTH'S ATMOSPHERE.
reported that after a storm of thunder and lightning
which broke over Osterrode, in Prussia, on the 22nd
April 1836, a yellow powder was found in the water
collected from two streams. It was formed of coarse
grains, like small hailstones, some of which were nearly
as large as peas, and these formed semi-transparent
drops, which were fragile, and could be easily broken
between the fingers. Afterwards, the grains became a
darker yellow, and harder ; so that they could no longer
be broken by pressure between the fingers. It was
proved that these yellow grains were sulphur, much purer
than the ordinary brimstone of trade. Mr. Dulk, and
his friend Mr. Lange, then requested the Mayor of
Osterrode to enquire of the proprietors of the streams
what had happened. The latter, and their servants, all
declared that there had been no sulphur before the storm,
and that after the storm, sulphur had not only been
found in the two streams, but in the gutters, and empty
vessels, such as saucepans and tubs, belonging to
artisans in the neighbourhood.
The so-called " sulphur rain " due to the pollen of
the Pine trees, often observed in Norway and Sweden,
has been occasionally witnessed also at Oleron in the
Basses Pyrenees (France).
Another cause of odour in the air, extending over
wide districts of marshy lands, is due to the volatile
substance characin, which I discovered in 1879. 1 It
forms very thin iridescent films on the surface of stag-
nant waters where algae abound, and on the water of
1 Chemical News, London, 1879.
ODOUR OF THE ATMOSPHERE. 43
tanks in which these microscopic plants are cultivated.
It is soluble in alcohol and ether, and is volatile, it
possesses the characteristic odour of marshy air, so
intense during hot summer weather in the flat districts
of Flanders, especially along the wide ditches which
border the Chaussfos, where I first noticed it. It has
the odour of the Cham, hence the name I gave it, and
to most persons is very disagreeable (botanists call one
of the species Chara fcetida) ; but all fresh water Algoe
produce it, Conferva, Palmella, Oscillaria, etc. ; and it is
often to be noticed, during hot weather, in glass
tumblers which have been wiped out with a towel on
which microscopic Algce have developed, through want
of cleanliness, and neglect of soaking the glass-towels
in boiling water. Characin may, of course, be produced
by the influence of microbes, but it is quite distinct
from them, being a well-defined substance, approaching
to the nature of camphor.
I have noticed, during my travels in Europe, that
on passing from one country to another, a different
odour is perceptible in the atmosphere. If we take
the boat to Ostend, for instance, we are at once struck,
on arriving, by the peculiar odour in the air ; and the
traveller who proceeds from Belgium to France, from
France to Germany, etc., can scarcely fail to notice the
peculiar change in the odour of the air when he changes
his abode to reside in another country. The cause of
this must be looked for in the various modes of life of
the inhabitants, and has little to do with the natural
constituents of the atmosphere. But even a journey
44 THE EARTH'S ATMOSPHERE.
from an inland region to the sea-coast makes us
aware of what is commonly called the " odour of
the sea," which was noticed as early as the days of
Alexander the Great; for the old author, Quintus
Curtius Eufus, distinctly informs us that the soldiers
of Alexander knew when they approached the sea by
the odour it diffused in the air " agnoscere se auram
maris"
Now, I have found that the fossil marine worms
(Teredo), which I used often to obtain from the tertiary
sands of Brussels, gave a distinct odour of the sea (aura
maris\ when broken with a hammer, or scratched with
a knife, shortly after being taken from the strata in
which they have been imbedded for myriads of cen-
turies. 1 This is infinitely more astonishing than the
accounts of the extraordinary persistency of the odour
of a grain of musk diffused through the atmosphere of
a large room for a great number of years.
Travelling on foot in Germany, I was often able, dur-
ing the night as well as by day, to distinguish when I
was approaching a beech forest or a pine forest, by the
different odour diffused through the air by each of these
trees.
All these facts show that the lower regions of the air
become impregnated with various volatile substances
which are constantly produced on the Earth's surface,
and the most minute quantities of which affect the
delicate tissue of the sensitive olf active nerves. I need
1 Phipson, " Note sur les Teredo fossiles," in the Comptes-rwidus of
the Paris Academy of Sciences, 1857.
ODOUR OF THE ATMOSPHERE. 45
not develop this subject further; but there is one
observation 1 desire particularly to allude to, namely,
the very delicious odour perceived in the air of a
country garden after a heavy summer shower. For
many years the cause of this odour escaped me com-
pletely until, one day in 1863, I found that certain
specimens of chalk taken in the open country of
Picardy, in France, developed a similar fragrance when
they were dissolved in diluted hydrochloric acid. For
a long time I was unable to trap the odoriferous sub-
stance which thus escaped with the carbonic acid ; but
finally I succeeded by passing the gas given off by the
chalk through a solution of bromine in water. The
bromine compound thus obtained was found to be analo-
gous to bromo-cedren, showing that the odour was due
to some essence like that of cedar. Hence, I was led to
conclude that the pleasant fragrance diffused through
the air in a country flower-garden after a heavy shower
of rain, is due to the displacement by the rain of the
flower-essences (essential oils) absorbed by the dry
porous soil during the hot days of summer. Many
years afterwards a well-known chemist in Paris made
some experiments, which fully confirmed my views in
this respect (Chem. News, Lond. 1891).
So much has been written upon the peculiar state of
oxygen known as ozone, that my remarks on this subject
must be very brief. 1 With us in England, I find it
1 Phipson, " La Force Catalytique,"etc. (Soc. Holl. desSc., Haarlem,
1858). See also the same author's papers in the Chemical News,
London, from 1860 to the present time.
46 THE EARTH'S ATMOSPHERE.
occurs chiefly with westerly winds blowing direct from
the Atlantic, and is very perceptible on going into the
open air after being for some time in the close atmos-
phere of a room. Those who wish to know what this
odour in the atmosphere is like, should place a stick of
phosphorus in some water contained in a large glass
globe, in such a manner that about half the phosphorus
stands above the water. In the course of a few hours
the air of the glass globe will have a very strong odour
of ozone, and will act upon a strip of paper steeped
in starch with a little iodide of potassium, turning it
blue.
The presence of ozone in the atmosphere of any given
locality renders the air highly tonic, bracing, and anti-
septic. It is rarely present in the atmosphere of densely
populated districts, except when a westerly gale is blow-
ing, as it is readily destroyed by the effluvia of animal life,
and in presence of organic matter prone to oxidation, or
in a state of decay. It is often present in sea-air.
Some experiments which I published long ago (loc. cit.)
have proved that whenever the atmosphere acts upon an
organic substance, such for instance as a slice of apple,
which it turns brown, the oxygen is immediately trans-
formed into ozone (called by some "nascent oxygen,"
because when oxygen leaves a compound it is in the
same state).
Again, ozone formed in an atmosphere at a very low
temperature such as is met with in the Arctic regions,
is liable to affect the flesh of animals exposed to it
before being cooked, inducing all the effects of putre-
ODOUR OF THE ATMOSPHERE. 47
faction, as was observed by the young and ardent
explorer Dr. Kane in the famous Grinnell Expedition
in search of Sir John Franklin. 1
1 Phipson, " Sur la putrefaction a 35 sous zero," in the Comptcs-
rendus of the Paris Academy, 1859.
CHAPTER IX.
The Electric Phenomena of the Atmosphere The Author's Re-
searches and History of Electric Discoveries Phosphorescence
of the Air Vibratory Nature of the Lightning-flash.
THE electric phenomena of the atmosphere have
always been a source of the greatest interest, and the
discovery of the nature of lightning by Benjamin
Franklin was one of the greatest achievements of the
last; century. A history of Atmospheric Electricity is
given in one of my former works, 1 where I have traced
the progress of this important branch of physical science
from its birth to the present epoch, giving an account
of Franklin's celebrated kite experiment and what led
up to it. Long electric sparks had been obtained from
the extremities of isolated metallic rods, raised high in
the air, by Dalibard in France, some months before
Franklin made his experiment ; but it was at the sug-
gestion of the latter. Such experiments are very
dangerous, and the young Professor Eichmann was
killed in this way at St. Petersburg.
It is not necessary that storm-clouds should be
present, for if an isolated condenser be suddenly
1 Familiar Letters on some Mysteries of Nature, London, 1876.
ELECTRIC IT Y PHOSPHORESCENCE. 49
launched into the air at any time, strong currents of
electricity (usually positive) are obtained. This experi-
ment, which I performed for the first time in company
with William Thomson (now Lord Kelvin), many years
ago, at the Philosophical Institution in Glasgow, was
merely an extension of the ingenious experiments of
Benedict de Saussure (1767), made in the Alps with
his electroscope : x whenever he raised the little instru-
ment above his head, the pith-balls separated, showing
that the electric tension of the atmosphere increases with
the height above the ground, and is generally positive.
M. Ch. Andre 2 concludes from observations, made in
a balloon, on the variation of the electric state of the
higher regions of the air, that in fine weather the electric
tension certainly does not increase with the altitude ;
but he does not appear to be entirely satisfied, at
present, with these observations, and hopes to repeat
them.
During a thunderstorm, this tension will change its
sign many times, often, in fact, with every flash of
lightning. In the experiment just alluded to, the
isolated condenser, communicating by a long wire with
Thomson's galvanometer-electroscope upon the table,
was attached to a long pole : when this was thrust
suddenly out of a window to a great height in the air,
the needle of the galvanometer was immediately set in
violent motion.
1 Benedict de Saussure, Voyages dans les Alpes, 4 vcls., 1779-1796.
' 2 Ch. Andre in the Comptes-rendus of the Paris Academy, 27th
-November 1893.
D
So THE EARTH'S A TMOSPHERE.
In recent times Mr. M'Adie has succeeded in getting
electric sparks from a kite raised in the air when there
were no clouds in the sky.
In August 1894, four soldiers were struck down, and
severely injured, in presence of the Duke and Duchess
of Connaught, at Aldershot, by a flash of lightning that
destroyed a captive balloon to which they were attending.
The day was characterized by a series of small thunder-
showers of short duration.
In dry summer weather, the dust raised by the French
postilions in Languedoc, during the afternoon, has been
known to remain suspended in the air the whole of
the night, on account of its electric state. That this
electricity is due to the friction of the horses' feet,
may be demonstrated by throwing a little fine dry
sand upon the condenser of a galvanometer-electroscope,
and blowing it off again ; in each case the needle of the
instrument is vividly deflected.
I have described, in my work above mentioned, a
number of wonderful phenomena due to atmospheric
electricity, such as the emission of light from the hats,
and raised hands, of travellers on the summit of a
mountain, the buzzing noise emitted by their Alpen-
stocks when thrust into the soil, which has been com-
pared to that of a boiling kettle ; the marvellous field-
lightning of the Jura which, during electric disturbance
of the air, plays over the pastures on the slopes of the
mountains, and has also been witnessed in Mongolia.
There, also, I have recorded the history of the discovery
of lightning conductors by Benjamin Franklin (1749-
/
[UNIVERSITY }
ELECTRICITY PHOSPHORESCENCE 51
1752), and the discovery, a few years
Thomas Eonayne, of London, concerning the electric
nature of fogs (1761), a subject since investigated by
Peltier and others.
An electrometer thrust into a dense London fog
often shows enough electricity to send a telegram
round the globe; and, in 1876, I published the fol-
lowing lines: "If after ascertaining the nature (or
sign) of this electricity, the fog could be supplied with
a plentiful amount of opposite electricity, I have no
doubt that it would be entirely dispersed in the course
of a short time/' l
Independently of the beautiful phenomena pro-
duced by the Aurora borealis in the highly rarefied
regions of the atmosphere, I should notice here those
gleams and flashes of light, probably of an electric
nature, which I witnessed accompanying the remark-
able swarm of shooting stars in November 13-14, 1866,
and which were noticed by others in the star-shower
seen the following year in the West Indies. An
account of this phenomenon was given in my note
to the Academy of Sciences at Paris in 1868. 2
The phosphorescence of the air, which allows a
traveller on the darkest nights, when there is no
moon above the horizon, to find his way in the open
country, and the phosphoric shining of .isolated masses
of cloud, often noticed, and described in my little
1 Phipson, Familiar Letters, etc., p. 37.
2 "Sur les phenomenes lumineux qui accompagnent les essaima
d'etoiles filantes " (in the Comptes-rendus, Paris, 1868).
52 THE EARTH'S ATMOSPHERE.
volume on Phosphorescence published in 1862 (my
first work in the English language), must doubtless,
as Humboldt suggested, be connected with the con-
stantly varying electric state of the higher regions of
the Earths atmosphere. These phenomena, which
were known to the Italian philosopher, Beccaria, in
the middle of the eighteenth century, have been often
witnessed by me.
I should also mention the phosphorescence of the
snow and ice on the glaciers of the Alps: the darker
the night the more brilliant is this effect, so that
it appears sometimes like a second sunset. The snow
which lies in the valleys of Piedmont, Switzerland, Valais,
etc., is likewise affected in the same way; the bluish
light emitted in these cases is due to phosphorescence ly
insolation. It is not remarked on snow which has fallen
shortly before night, and which, consequently, has not
been long exposed to the sun.
Although Franklin and his successors have per-
fectly demonstrated the identity of lightning and the
electric spark suspected years before by Otto von
Guericke and Dr. Watt yet the exact cause of the
light that flashes through the atmosphere, and of
its tiny representative which rushes between the poles
of an electric battery, is quite unknown. By modifying
the medium, we modify the spark; so that in highly
rarefied air, for instance, it takes the appearances of
the Aurora borealis. What is the cause of the sudden
light which issues from the storm-cloud, or through
the air how is that light produced ?
ELECTRICITY PHOSPHORESCENCE. 5 3
Some writers have imagined that lightning was due
to the combustion of hydrogen gas, supposed to exist
in the higher regions of our atmosphere ; or to that
of carburetted hydrogen (marsh gas) which has really
been detected on several occasions in the air ; or,
again, to that of nitrogen, as in the celebrated experi-
ments of Cavendish, who obtained nitric acid by
passing electric sparks through atmospheric air. Nitric
acid is, indeed, present, in minute quantities, in storm
rain, and I am of opinion that all rain likewise con-
tains it.
My own idea is that lightning is due to a vibration
of the air similar to what occurs in the little instru-
ment known as the briquet a air, where sudden
compression of the air in a cylinder by a blow upon
the piston will cause it to ignite a piece of tinder.
A similar vibration of the air is caused by the rupture
of the extremity of a Prince Eupert drop, which
causes a sudden light, and by the discharge of an
air-gun, also by the rupture of a glass vessel exhausted
of air.
Similar vibrations, producing light, occur when
crystals form in liquids, or by cooling after fusion, or
by sublimation, or when divided suddenly by cleavage
phenomena which I have witnessed scores of times. 1
So that the minutest molecular vibration is capable of
yielding a sudden flash of light.
The close calm weather which often precedes thunder-
1 Phipson, Phosphorescence, or the Emission of Light by Minerals,
etc., 1 vol., London, 1862.
54 THE EARTH'S ATMOSPHERE.
storms in our temperate climate, is accompanied by
an increase in the various odours perceived in the
air. The perfume of flowers is very much stronger
for awhile; and, in country places, it is not unusual
to perceive, at such times, the disagreeable odour of
cess-pools all over the district a fact which clearly -
points to the necessity of a more perfect system of
drainage and disinfection in our country homes.
CHAPTEE X.
An Unexplained Condition of the Atmosphere Effects of Glare
Snow-blindness Hemeralopia and Amaurosis.
THERE is a certain, hitherto unexplained, condition of
the atmosphere, which usually lasts for a few hours
at a time, and rarely more than one day, or, perhaps,
two days. During this condition the optic nerves
of men and animals are painfully affected. I allude
to what is commonly called " glare," not unfrequently
perceived at the seaside, and often when the sun
is not shining brilliantly, but is hidden by thin cloud,
or haze.
The existence of this painful "glare," even when
the sun is dimmed, is a subject which has not been
fully studied. I feel convinced that we have in the
solar spectrum, besides the rays of light and heat, and
the actinic, or chemical rays, others which specially
affect the nervous system in the higher animals, and
which appear to act also on those 'lower forms of
life, in some of which no traces of a nervous system
have, as yet, been discovered. This peculiar condition
of the atmosphere affects some people more than
others. Many are obliged to wear coloured glasses
56 THE EARTH* S ATMOSPHERE.
in order to avoid its effects, or to pull dowu the brim
of their felt hats to a level with the lower eyelids,
as they do at Naples.
Snow-blindness is supposed to be occasioned by the
vivid reflection of the solar light from the white mantle
of the brilliant white crystals which covers the ground,
and more or less complete amaurosis is produced,
especially in aged persons, by the bright solar radiation
on the sea-coast, or by the light from brilliant white
houses in inland cities.
One of the most remarkable cases of snow-blindness
ever reported is that by the late General Miller, in
the Edinburgh New Philosophical Journal (1835) : A
division marching from Cuzco to Puno, in Peru,
halted at Santa Kosa. During the night, snow fell
abundantly, nevertheless the march was continued
next day, when, with few exceptions, the whole of the
soldiers were attacked with sore eyes, " due to a disease
called by the natives norumpi. It produces almost
total blindness for some time, and great pain. There
is also delirium of a peculiar kind, and it is often fatal.
The division in question lost one hundred men in
fifteen hours from this affection. The disease generally
lasts two days."
Dr. August Berlin, of Stockholm, has proposed a new
theory for snow-blindness. He went on an expedition
to Greenland in 1883, during which he had ample
opportunities for observing it.
The geographical distribution of the affection closely
follows the isothermal lines in the three continents
GLARE AND EYESIGHT. 57
bordering on the North Pole ; it comes further south
in America and Asia than it does in Europe. It is-
also met with in very elevated regions, even under the
tropics. In the temperate zone it occurs occasionally,
but in a milder form. Its cause, according to Dr.
Berlin, resides in great dryness of the air, and intensity
of the solar rays.
To prevent snow-blindness the Esquimaux use a
disk of thin wood with a minute transverse slit in the
centre. They call these wooden spectacles their " snow-
eyes." Instead of this, goggles made of moderately
fine wire network, without glass, have been recom-
mended.
Medical men class these atmospheric effects upon the
optic nerve under the term of hemeralopia (or " night-
blindness," because they are chiefly observed at night).
It is not uncommon that a considerable number of
soldiers become thus completely blind during the night,
and recover their sight again at daybreak. The com-
plaint comes on periodically every evening, and may
last for a fortnight, or even for a whole month, when
it disappears without leaving any traces.
The army surgeon, Dr. Better, saw sixty of his men
struck down in this way at Wissembourg, just before
the Franco -Prussian war ; and the troops in garrison
at Strassburg suffered in a similar manner. Generally
speaking it is cured, in mild cases, by keeping the men
in the dark for two or three hours; or, sometimes, for
twelve hours. In 1891, Dr. Schirmer endeavoured to
explain this extraordinary atmospheric effect upon the
58 THE EARTH'S ATMOSPHERE.
eyes, by reporting it to an action upon the pigment-
cells of the retina. But it still remains a mystery.
That same year Dr. Venneman described an " epidemic "
of hemeralopia which he observed in the neighbourhood
of Louvain (Belgium). Forty-two cases of this peculiar
affection came under his observation, and embraced all
classes of people, children being more generally affected
than adults. Fever, with headache, preceded the affec-
tion of the eyes, and lasted for two or three days.
With the appearance of these symptoms the ophthalmo-
scope revealed a slight retinal oedema about the disc,
especially along the course of the vessels, with diffuse
streaks and markings of black pigment. When normal
vision returned these appearances gradually vanished.
It is, therefore, an atmospheric effect upon the retina,
or optic nerve; but no one has yet been able to
determine in what consists the special condition of our
atmosphere which produces these curious and painful
effects. So little does the last-named physician suspect
the real cause, that he looks upon the cases at Louvain
as an epidemic, similar to influenza, confusing it with
the amaurosis so often noticed, of late years, after
attacks of that disease.
CHAPTEE XL
Solid Substances in the Atmosphere which fall upon the Earth, or
can be detected in suspension in the Air The Author's first
Discovery of Iron Particles in the Air, after the Meteor
Stream of November 1866 Confirmed by other Observers
His detection of Fossil Bacteria in the Air ; and of minute
Crystals of Ice His Observation of Bundles of Grass trans-
ported for hundreds of miles A Similar Case observed by
Boussingault Presence of Salt and Sulphate of Soda in the
Air Gossamer Birds and Insects Cosmic Dust Ex-
plosion of Meteors Periodic Plants Transportation of
Frogs, Stones, Volcanic Ash, etc. List of Extraneous Sub-
stances Mode of collecting Bacteria Observations by
Pasteur, Miguel, and the Author.
As early as 1854, I examined a singular mucilaginous
substance mentioned by Mulder and Berzelius under
the name of "Mucilage atmosphdrique" It is found
lying in the low Flemish pasture lands in the neigh-
bourhood of stagnant pools, and the peasants of the
Netherlands believed it to be dropped by shooting-
stars, since it is occasionally seen at ight to be phos-
phorescent. I shall never forget the youthful ardour
with which I went through the early morning mist
in search of this mysterious atmospheric mucilage,
trudging over the damp fields which surrounded my
60 THE EARTH'S ATMOSPHERE.
father's house in the neighbourhood of Brussels, and
scattering hundreds of large blue crows, which rose, on
my approach, from the edges of the shallow patches of
stagnant water. On careful examination it was found
to be frog-spawn, which had been swallowed and then
voided by the immense blue crows which are so
numerous in those districts.
In connection with this curious subject I have since
found that in Donovan's British Birds (1794, vol. iv.,
plate 77, the Winter Gull) he says : " Mr. Pennant
observes that the gelatinous substance known by the
name of Star spot, or Star jelly, owes its origin to this
bird, or some of the kind, being nothing but the half-
digested remains of earth-worms on which these birds
feed, and often disgorge from their stomachs/' The
Winter Gull (Larus hybernus) is a common bird in
England, and frequents inland rivers, fens, and moist
meadows, hundreds of miles from the sea, in winter
time ; hence its name. Its general colour is white, with
a few brown spots on the wings, etc.
Mr. Morton, in the Natural History of Northampton-
shire, says : " In the course of my correspondence with
J. Platt, of Oxford, I recollect his having mentioned that
once meeting with a lump of this Star jelly, on ex-
amining it he found the toes of a frog or toad still
adhering and undissolved, and from thence he con-
cluded it to be the remains of one of these having been
swallowed whole ~by some bird, and the indigestible parts
brought up in the condition he found it."
About the same period, when prosecuting my studies
FALLS OF FOREIGN BODIES. 61
at the University of Brussels, I was called upon to
make a chemical analysis of the dust collected by one
of my professors from the air of houses in that city.
I found that it consisted almost entirely of organic
matter, leaving only a minute quantity of ash when
burnt, in which soda appeared to be the principal
ingredient.
Many years later, at the commencement of winter,
I examined the first fall of snow in the neighbourhood
of London, and found it teeming with organic germs and
unicellular Algce.
In 1866, shortly after the celebrated star-shower
of November, described in one of my former works, 1
I exposed to a south-westerly gale, plates of glass
covered with glycerine, which were afterwards ex-
amined under the microscope, and revealed some black
specks which contained iron, and gave yellow chloride
of iron by treatment with hydrochloric acid. This
was the first experiment of the Jcind ever made, and is
recorded in my book. Since then this observation
has been confirmed by Cunningham, Tissandier, and
others, who have all found iron, probably of cosmic
origin, floating in the atmosphere of our Earth.
Ten years previously I had used the same device
(with solution of gum instead of glycerine), both in
France and in Belgium, for collecting substances carried
through the air by the wind ; and among other curious
1 Phipson, Meteors, Aerolites, and Falling Stars, London, 1867.
The description is an Appendix, as the work was written long before
that famous star-shower occurred.
62 THE EARTH'S ATMOSPHERE.
objects thus collected I have met with the microscopic
hairs (pili) of certain Alpine plants, flourishing
hundreds of miles from the spot where the experi-
ment was made.
I have more recently collected in this manner ex-
tremely minute circular cells, which resisted a red heat
in contact with the air, and were found to consist
chiefly of silica. They appeared to be, in fact, fossil
bacteria, 1
It also fell to my lot, in my student days, to place
beyond doubt the existence of crystals of ice in the
atmosphere minute crystals of ice suspended in the
air, which are the cause of the phenomena known as
Solar and Lunar halos : One night during the spring of
1855, a magnificent halo of 22 degrees encircled the moon
as seen at Brussels. It is generally admitted that these
halos portend " rain within twenty-four hours," which is
explained by a change of wind a warm southerly
current mixing with the air in the higher regions
charged with ice-crystals, and bringing down the latter
as rain. On this particular occasion things occurred in
a rather different manner; for, the following morning
as I was proceeding to the University for the early
Chemical Course at eight o'clock, I found the air full
of minute floating crystals which glittered in the bright
sunshine like myriads of small diamonds. It was a
most curious sight, and one never to be forgotten. The
tiny crystals fell all the morning, covering objects on
1 Phipson, "Grains of Silica and Micrococci in the Atmosphere,"
published in the Chemical Neivs, 1881.
FALLS OF FOREIGN BODIES. 63
the Earth's surface with a thin layer resembling hoar-
frost, and finally changed to rain during the afternoon.
Here is another curious observation which I find
among my notes. Standing one morning during the
month of June 1861, on the banks of the Eiver Thames,
near London, I was a witness of the following singular
spectacle :
The day was calm, with only a slight westerly breeze,
there was bright sunshine, and the sky was blue.
Suddenly there appeared moving specks in the atmos-
phere to the west of the spot on which I stood, and
evidently at an enormous distance. They were like a
very distant flight of birds ; but they got much larger
than any birds, as they approached. At last some of
them began to fall into the river near Putney bridge \
and two or three of these curious objects fell into my
father's garden. On examination, they were found to
be recently cut grass, twisted into circular masses, much-
larger than a man's head. I knew that no grass had
been cut for hay within hundreds of miles of my
residence, and I at once assimilated this phenomenon
to the falling of volcanic ash upon ships far out at sea,,
and hundreds of miles from any volcanoes, of which
instances have occasionally been put on record.
Many years afterwards, I found that a precisely
similar phenomenon had been witnessed by the
celebrated Boussingault at Caracas, in Venezuela, and is
mentioned in the second volume of Humboldt's Views
of Nature.
M. Boussingault, who was then Professor at the
64 THE EARTH* S ATMOSPHERE.
School of Mines at Santa-Fe de Bogota, whilst climbing
the hills of Caracas, witnessed in the middle of the
day, during an excursion to the summit of Mount Silla,
a phenomenon which appeared to prove in a striking
manner the existence of ascending currents of air. He,
and his companion, Don Mariano de Eivero, saw
numbers of white, shining bodies rise from the Valley
of Caracas, and reach the summit of Mount Silla, 5400
feet high, whence they fell on the opposite slope. This
phenomenon lasted for an entire hour, without any
interruption. At first, M. Boussingault imagined it
was a flight of birds, but he was soon able to convince
himself that these bodies floating in the air were small,
round bundles of grass, chiefly composed of the species
Aira tenacissima, which is plentifully mixed with
Agrostis grass of the valleys of Caracas and Cumana. 1
The account of the phenomenon witnessed by me was
published in the Comptes-rendus of the Paris Academy 2
before I knew of Boussingault's observation.
The presence of salt (chloride of sodium) in the air
of the sea-coast, especially when a brisk breeze plays
upon the spray of the waves, is a matter of common
experience. But it is not so generally known that
-another sodium salt, namely, sulphate of soda, in the
solid state, appears to be constantly present in the atmos-
phere, at least in the lower regions.
A supersaturated solution of sulphate of soda
1 Humboldt, Tableaux de la Nature, vol. ii. p. 37.
2 Phipson, " Sur une pluie de foin," in the Comptes-rendus, Paris,
1861.
FALLS OF FOREIGN BODIES. 65
crystallises immediately the bottle containing it is
opened, in whatever place the observation may happen
to be made, whilst solutions, equally saturated, of other
salts do not present the same phenomenon.
This fact, which has been brought to light by
F. Parmentier and M. Margueritte, 1 appears to prove
most conclusively that sulphate of soda must be constantly
present in the lower regions of the atmosphere, and this
salt being universally suspended in the air, supplies the
necessary microscopic nucleus-crystal, which causes the
whole solution to solidify the moment the bottle is
opened.
It has long been known that butterflies and other
insects are occasionally transported, by aerial currents,
from the valleys to the summits of the highest moun-
tains, and far out to sea; and the spiders' webs which
are found floating in the air (generally, with us, in
October, though I have seen them also in March, both
at St. Cloud, near Paris, and in the South of England),
are alluded to by many of our poets as "gossamer."
In this respect I shall never forget a journey I once
made, in October, from Paris to Brussels, by the line
then recently constructed through Erquelinnes. On
alighting at the station of Erquelinnes, I noticed that
the funnel of the engine was covered with these spiders'
webs, and appeared just as if it had be^en wrapped in a
silk shawl several inches thick. The description of the
particular species of spider that migrates in this manner
by the currents of the atmosphere is given by Kirby
1 Comptes-rcndus of the Paris Academy, 1889.
66 THE EARTH'S ATMOSPHERE.
and Spence in their great work on Entomology. I
have since seen it rise in the air, like a fly, from the
summit of plants in my garden at Putney, in September,
by means of its invisible thread.
Doubtless, the migration of birds is aided in a similar
manner by currents of air. Our swallows usually
appear in great numbers after a stiff gale has been
blowing for many hours. It is difficult, however, to
account for the manner in which the minute red spiders,
known as social mites, are transported through the air.
Suddenly, some fine morning, they will be found
clustering by thousands, on nails, or other prominent
objects, at the top of gates, or fencing, disappearing, in
a few days, as mysteriously as they came. This singular
occurrence has been sometimes witnessed in Putney
and other westerly quarters of London.
In another place, I have given numerous instances
of what is supposed to be Cosmic dust?- as distinguished
from the better known dust, or ashes, due to volcanic
eruptions, such as those of Krakatoa which, not very
long ago, diffused into the atmosphere immense quanti-
ties of volcanic ash that remained suspended in the
atmosphere for several years, producing the most
gorgeous effects of sunset for two or three years in
succession. It is very probable that fine sunsets of
a less remarkable kind are often due to a similar
cause.
The whole subject of Cosmic dust, and other sub-
1 Phipson, Meteors, Aerolites, and Falling Stars, 1 vol., London,
1867.
FALLS OF FOREIGN BODIES. 67
stances observed to fall from the atmosphere, has
been discussed in Chapters XIII. and XVII. of my
work just alluded to. The late learned Baron von
Eeichenbach long ago collected virgin soil from the
summits of mountains in Germany, and found it con-
tained traces of nickel, a metal invariably present in
aerolites. I did the same, in Waldeck, in 1865, tak-
ing the earth from places where human industry had
not yet penetrated, and with similar results, which
shows that meteoric dust, the produce of meteors,
finds its way through the air to the surface of the
Earth.
Professor Nordenskiold asserts that he has, also,
collected meteoric dust in the snows and ice of the
Arctic regions. But all these observations require
more careful discussion than they have yet received,
and so does that one published by Mr. Baumhauer,
who found iron pyrites enclosed in hailstones which
fell in Holland. 1
The cause of the explosion of a meteor in the Earth's
atmosphere is due to the sudden rise of temperature on
the surface (which is thereby fused, whilst the interior
is most intensely cold), by the friction with the air
through which it rushes. It has been estimated that
if the speed of a meteor is only slackened by j<^<jth,
during its passage through the air, its. temperature is
raised on the surface to a much higher degree than
that at which iron burns ; and I have proved by actual
experiment, that the sudden heating of the surface of a
1 Comptes-rendus, 1872.
68 THE EARTH'S ATMOSPHERE.
body intensely cold in its interior, as a meteor coming
from cosmic space must be, is quite sufficient to
explain the explosion and rupture of the aerolite. 1
The great Italian naturalist, Spallanzani, has declared
that he was never able to discover that curious plant,
Nostoc commune, though he had often sought for it
along garden walks, after showers of rain; and he
thought botanists were mistaken in giving to it the
specific name "commune" Now, I have noticed that
the algae of the Nostoc group appear abundantly
in certain years and in certain places, without any
apparent cause ; and then disappear, apparently for
ever, from these localities. The same singular pheno-
menon is found to occur with more highly organized
plants ; for instance, with the rare " bloody-finger grass "
known to botanists as Digitaria sanguinalis, which
appeared one year in my garden near London, though
it is only to be found, now and then, as a great rarity,
in the county of Norfolk. I could cite many other
instances, not only of plants, but of animals, that pay
us periodic visits in this manner. In 1893, the summer
of which was unusually hot and dry, I found in my
garden a species of wasp which inhabits the South of
France, and is never seen in England; and I have
found a dead African locust on the wild, deserted
sandhills beyond Ostend, on the coast of Flanders.
All these facts are due, in the first instance, to
accidental transportation by gales of wind, which carry
1 Phipson, "Sur 1'explosion et la chute des meteores " in the Comptes-
rendus, 1869.
(UNIVEKG;TY
FALLS OF FOREIGN BODIES. OF 69
germs of algse, seeds of grasses, and other^laSfa, "lic.,
to immense distances, and they germinate and flourish
wherever the conditions are favourable. These con-
ditions appear to be periodically favourable only, for
any given point of the globe; and when they cease
to be so, the plant, or animal, disappears. It is a
subject well worthy of more investigation than it has
hitherto received.
Waterspouts have been known to carry frogs for
many miles from marshy districts, and deposit them
in large numbers in places where they were never seen
before.
In 1864 I analysed 1 some fragments of stone that
were carried through the air from the neighbourhood
of Dudley to Birmingham, where they fell in the streets
during a violent storm, and were supposed to be
aerolites. My examination showed that they were
really fragments of greenstone rock, known in the
locality as "Bowley Bag" (the "rock of Bowley"
which forms a hill near the village of Eowley in
Staffordshire).
Many old accounts of " rain of Sulphur " apply only
to a fall of the yellow pollen of the northern pine trees,
which is scattered by the wind; but there are well-
authenticated cases of real sulphur falls, to one of
which I have made special allusion mi a preceding
page. Volcanic ash of various colours red, grey, and
black is not unfrequently brought down by the rain
at great distances from its origin ; and storm rains in
1 Brit. Assoc. Report, 1864.
70 THE EARTH'S ATMOSPHERE.
the West India islands often yield a large amount of
sea-salt. The same thing occurs in other localities.
The principal extraneous substances which, according
to my personal experience, appear to exist at almost all
times in the atmosphere of the Earth, may be rapidly
enumerated as follows :
Water ; carbonic acid ; sulphur ; chloride of sodium ;
sulphate of soda ; iron (meteoric) ; silica (fossil bacteria,
or micrococci) ; desmids and foraminifera ; spores of
Algce ; unicellular Algce (always present in rain and
snow) ; carbonaceous matter of unknown nature ; hairs
(pili) of various plants; debris of human vestments (cotton
and woollen fibres of various colours) ; essences of flowers
(odour of the air after a summer shower); vapour of
characin (cause of the odour of marshy soils and
ditches) ; traces of iodine and hydrochloric acid (in sea-
air) ; traces of nitric acid (in the rain of thunderstorms) ;
ammonia ; dust of carbonate of lime ; volcanic ash, grey,
red, and black; organic matter of various kinds, that
can be condensed in strong sulphuric acid, which it
turns brown.
In the dense London fogs seleniuretted hydrogen has
been mentioned, but without sufficient proof, as the
cause of the choking sensation these fogs produce.
Sulphurous acid is often present (from the combustion
of pyritous coal, and in volcanic regions) ; it first
reddens blue litmus paper, and then bleaches it. Hydro-
chloric acid, present in the air near chemical works,
only reddens litmus, and turns the leaves of trees
yellow. Sulphuretted hydrogen is often present in town
FALLS OF FOREIGN BODIES. 71
air, and organic compounds of sulphur, due to the fer-
mentation of sewage and refuse of various kinds.
Ammonia is present in the air of the open country to
the extent of 3 parts for every 100 parts of carbonic
acid ; on some occasions it has been detected in much
larger quantities in the air of Regent Street, London,
where it turns to a blue colour a strip of moist red
litmus paper carried on the hat. London air, also, often
shows carburetted hydrogen, due to gas escapes ; and, in
the country, proto-carluretted hydrogen, or marsh gas,
constantly rises in bubbles from stagnant pools which
have much decaying vegetable matter in their mud, and
finds its way into the air. This is also the gas which
issues from the seams of coal in mines, and gives rise to
disastrous explosions. Boussingault has detected it,
more than once, in very minute quantities, in atmos-
pheric air taken from various localities, far from towns.
The germs of various pathogenic bacteria can be col-
lected in cotton wool, or on plates of glycerine, such as I
have before mentioned; they can then be transferred
to a sterilized gelatine mixture, in which they develop,
and can afterwards be inoculated into the tissues of
various animals to prove their toxic nature. 1
Dr. Miguel has collected the urea ferment in the
streets of Paris (and it may readily be met with in our
metropolitan railway stations). Previously to this,
1 Pasteur used guncotton for these experiments, which, after it
has collected the germs, etc., in the atmosphere, can be dissolved in a
mixture of alcohol and ether, and so set them at liberty for micro-
scopic examination.
72 THE EARTH'S ATMOSPHERE.
Pasteur collected the grape vine ferment during vintage
time in France. I was desirous of repeating this ex-
periment of the celebrated savant, whose friendship I
enjoyed during my four years' residence in Paris, and
whilst a heavy gale was blowing for about three days in
London, at the time of the vintage in France, I passed
some hundreds of gallons of air into a solution of sugar
with the hope of thus catching some grape ferment.
The solution was afterwards placed in a stove, kept, for
some days, at about 70 Fahr. to promote fermentation.
No alcoholic fermentation was obtained (I am afraid
my solution contained too much sugar) ; but the bottle
having been kept hermetically sealed for several months,
there developed in it an extraordinary brownish-white
fungus in long filaments, a species of Byssus, whilst the
liquid became of a golden-yellow colour, and slightly
acid.
CHAPTER XII.
Air essential to Sound Mountain Air Dr. Viault's important
Observation Height of the Atmosphere Determination of
Altitude Effects on the Barometer and Thermometer
Temperature at the Limits of the Atmosphere Hermite's
recent Experiments with small Captive Balloons Heights
of Clouds Determination of Water- vapour in the Air
The Eain-band of the Spectroscope.
ATMOSPHERIC air is a good conductor of sound, and a
better conductor when moist than when dry.
If no atmosphere existed, sound would be absent from
our world.
As we rise on the mountains, the air becoming less
and less dense, sound diminishes remarkably ; so that
the crack of a rifle is quite a slight noise in the hands
of a Chamois hunter in the Alps ; and even thunder is
far less terrible on the mountain heights than in the
valleys.
Mountain air affects the breathing of persons un-
accustomed to it : the air being less dease contains less
oxygen in a given volume, whilst the capacity of the
lungs, of course, remains the same. But Nature ensures
a proper degree of hsematosis by increasing the number
of Hood-corpuscles of those who reside for any length of
74 THE EARTHS ATMOSPHERE.
time on the mountain heights. This most remarkable
discovery is due to Dr. Viault, of Bordeaux (France),
who made it originally on the slopes of the Andes, in
South America, and has since confirmed it in his travels
on the mountains of Europe.
With regard to the action of mountain air upon the
mental powers, Professor Janssen, during his recent
ascent of Mont Blanc, found that when he was not
exhausted by physical exertion, his mental functions
remained perfectly clear. When he took physical
exercise he was rapidly fatigued, and quite unfit to
perform any calculations, or other mental labour.
A number of interesting questions and some remark-
able phenomena are connected with the height to which
our atmosphere extends above the level of the sea.
With this subject is connected the curious problem,
whether gases, deprived of all pressure, can expand in-
definitely, which formerly attracted the attention of my
late friend M. Babinet, the eminent successor to Francois
Arago, at the French Institute, and Bureau des Longi-
tudes, and to which I hope to refer again.
Some have thought, indeed, that the Earth's atmos-
phere has no limit. Others suppose that at an elevation
of forty to fifty miles the elasticity (tension) of the air,
and the attraction of gravitation, must balance each
other.
Applying to the total height of the Atmosphere the
law of the diminution of density as observed in the
lower strata of air in which we live, we arrive at the
conclusion that at a height of about forty-five miles,
SOUND HEIGHT AQUEOUS VAPOUR. 75
the atmospheric air must be as rarefied as in the
exhausted recipient of the best-constructed air-pumps.
From a practical point of view, it may be stated,
at once, that air in which man may live does not extend
to ten miles above sea-level, probably not to eight miles,
as proved by recent balloon ascents.
It has been attempted to ascertain the absolute height
of the Earth's atmosphere (which the eminent meteor-
ologist, Dr. Buist, declared to be unknown), by consider-
ing the height of the Aurora borealis, and that at which
meteors are seen to shine. A distinguished American
observer, Mr. Newton, once expressed the opinion that
there must be some kind of an atmosphere at 500 miles
above the surface of the Earth.
The height of luminous meteors, determined parallacti-
cally by various observers, gives results showing that
they shine at very different heights, namely, 48 miles,
72 miles, and 132 miles.
The ingenious polarization experiments made by the
French Astronomer, M. Liais, in his voyage to Eio de
Janeiro, alluded to in my work on Meteors (chap, xix.),
point to 200 miles as the height to which the Earth's
atmosphere actually extends.
It seems to be beyond doubt that the Aurora borealis
glows at a greater elevation than that at which shooting,
stars become visible.
The celebrated Laplace, in his Exposition du Systeme
du Monde, says the solar rays reflected from the molecules
of air before the rising, and after the setting of the sun,
producing what is termed dawn and twilight, which
76 , THE EARTH'S ATMOSPHERE.
spread to more than 20 degrees from the sun, prove
that the most distant molecules of the atmosphere are
at least 30 miles above the Earth's surface. Now, if we
suppose that a given volume of air, considered at the
surface of the Earth, increases, as we rise, according to
the square of the distance , the volume which corresponds
to 45 or 50 miles, where the barometer would be at
inches (that is, where all pressure ceases), would be
about 34,646 cubic miles, the cube-root of which gives
about 32 J miles, a figure approaching very nearly to
that of Laplace just mentioned.
As we rise in the atmosphere it becomes more rare-
fied; the diminished pressure affects both the baro-
meter and the boiling-points of liquids.
Practically speaking, the barometer falls about j^th
of an inch for every 100 feet of elevation. Whilst at
sea-level the atmospheric pressure of 15 Ibs. to the
square inch keeps the barometer at 30 inches, and
the boiling-point of water at 212 Fahr., these figures
both diminish in proportion to the altitude. 1
Travellers sometimes make a rough guess at the
altitude to which they have ascended on a mountain
slope, by boiling the thermometer : there is a difference
of some 4 to 5 Fahr. for every 1000 feet of elevation.
Actual experiment has given the following results :
1 Atmospheric pressure varies slightly at sea-level in various parts
of the world ; it is slightly less in the tropics, and increases towards
the poles. The same has lately been found to be the case for gravi-
tation (Defforges, 1893). This is as it should be, for after all,
atmospheric pressure is merely the effect of gravitation upon the
material of the Earth's atmosphere.
SOUND HEIGHT AQUEOUS VAPOUR. 77
At sea-level in England, water boils, according to my
thermometer, exactly at 212 Fahr., when the baro-
meter is at 30 inches. On the summit of the Waldeck
and Hartz mountains in Germany, at 2000 feet of
altitude, I found, with the same thermometer, 208 Fahr.
as the boiling-point of water. At a height of 6800
feet, on the summit of the St. Gothard (Alps), 200
Fahr. has been noted. At Quito (South America), at
9340 feet, water boils at 195 Fahr. ; on the summit
of Etna (10,900 feet), at 192 Fahr.; and on the
highest summit of Mont Blanc, at an elevation of
15,600 feet, the temperature of boiling water was found
to be 182 Fahr.
The refrigeration, or coldness of the atmosphere,
increasing as we ascend, the thermometer is usually
about 1 Fahr. lower for every 300 feet of altitude; but
this varies somewhat with the locality, and with the
direction of the wind at the time of observation.
The cold air of mountain heights throws out moisture
in the shape of cloud; but as we ascend beyond this,
the air becomes drier, and only on rare occasions, ac-
cording to Fitz-Eoy, have clouds been distinguished
actually above the summits of the highest moun-
tains.
Hitherto, no one has ascended in a balloon much
above the summits of the highest mountains, says the
eminent author just named ; and it is not likely that
it ever will be achieved, since man's existence at such
altitudes is impossible. Small captive balloons pro-
vided with self -registering thermometers, and very light,
78 THE EARTH'S ATMOSPHERE.
self -registering barometers made of aluminium, have
quite recently been used in France, by Gustave Her-
mit e, to ascertain the temperature of the atmosphere at
yreat altitudes. At a height of 12,000 metres a
temperature of 51 C., and at 10,000 metres 41 C.
were noted. 1 Mendeleeff s calculations show 42 C. ;
Vallot's observation on Mont Blanc -45 to -47 C.,
as the temperature at the extreme limits of the Earth's
atmosphere, 2 and G-laisher from his dangerous balloon
ascent in 1862, estimated 40 C. Forty degrees below
freezing-point Centigrade is the temperature at which
quicksilver becomes solid; it corresponds also to 40 a
Fahr. (72 below freezing-point Fahrenheit). Layers of
fog, or cloud, lie at various heights, generally not ex-
ceeding two miles, and currents of wind set in different
directions simultaneously; sometimes, clouds float in
one current, sometimes in another, and occasionally
between two currents (Fitz-Boy). On the slopes of
mountains, and by balloon ascents, depths of more than
2000 feet of cloud have been measured.
Fogs, or clouds, are sometimes dry, and sometimes wet \
in other words, they wet the Earth and objects on or
above its surface, or they do not. This appears to be
entirely dependent upon their electrical state (positive
or negative).
A fog is exactly the same as a cloud ; a traveller on a
mountain is sensible of no difference; but the very
1 Hermite, Comptes-rendus of the Paris Academy, 22nd January
1894.
2 Vallot, Comptes-rendus, 5th February 1894.
SOUND HEIGHT AQUEOUS VAPOUR. 79
highest clouds are supposed to consist chiefly of thin
layers of snow, or ice crystals. According to one of
our most eminent meteorologists, no trace of cloud has
ever "been observed at a greater height than seven miles.
The following heights to which the various kinds
of clouds rise in the atmosphere is now generally
admitted :
Cirrus cloud to 35,000 feet ; cirro-stratus to 27,000 ;
cumulus to 15,000; and the nimbus, or rain-cloud, not
above 5000 feet.
Two photographic cameras, placed half a mile apart,
and in telephonic communication, suffice to determine
the parallax of the clouds observed, and thus to get
their exact elevation. We shall say more on this
subject a little later.
The quantity of water vapour in the atmosphere, at
any given spot upon the Earth, varies incessantly with
the pressure and temperature, the time, and the direction
of the wind. The point at which it is saturated with
moisture, and deposits dew, or lets rain fall, is ascer-
tained by the difference of reading between the dry- and
wet-bulb thermometers.
Supposing the dry-bulb thermometer indicated 60
Fahr., and the wet-bulb 56 : the difference, 4, being
subtracted from the wet-bulb indication, leaves 52*
as the temperature at which the air would be saturated
with moisture. Or, if we double this difference and
subtract the sum from the dry-bulb indication, we get
the same result. The greater the difference of reading
between these two thermometers, hanging side by side,
80 THE EARTH'S ATMOSPHERE.
the drier is the air ; when the difference is very slight,
1 or 2 only, rain is about to fall.
The rain-band of the Spectroscope, first alluded to
by Professor Piazzi-Smyth as being due to aqueous
vapour in the Earth's atmosphere, and as being situated
on the red side of the line D of Frauenhofer, increasing
in intensity, or receding from the C line, according to
the nearness or quantity of rain to be expected, seems to
me to be less practical, and less reliable, than the
indications of the wet-bulb and dry-bulb thermometers.
The use of the spectroscope for this purpose requires
further investigation.
When the air of the atmosphere is saturated, at the
ordinary temperature of an English summer, it contains
about 1 per cent, of moisture : Carbonic acid varies from
0'03 to 0*06 per cent., and water from 0'6 to 0'9 per cent.
The quantity of ammonia is to that of the carbonic acid
as 3 is to 100, nearly.
Professor Macagno, in a series of interesting analyses
of the air in the neighbourhood of the Observatory at
Palermo, in Sicily, which stands only some 200 feet
above sea-level, has shown that carbonic acid, and
organic matter, increase in the air as the temperature
rises; that rain invariably purifies the air; and that
there is a slight diminution in the amount of oxygen
during the prevalence of the sirocco.
CHAPTEE XIII.
Air the only Gas that can be breathed Important Work of the
late Wilson Phipson The Compressed-air Work of Daniel
Colladon Dr. Junod's Application of rarefied Air Air-
bath Establishments Disinfection Special Action of given
Disinfectants Absence of Microbes in Pure Air.
THREE-QUARTERS of a century ago, the late Dr. Thomas
Thomson, of Glasgow University, pointed out in his
celebrated work on Chemistry, 1 that air is the only gas
which man and the higher animals can breathe for any
length of time. Many gases are promptly fatal ; others
can be breathed only for a very short time.
This shows the immense importance of good ventila-
tion in crowded edifices. Here I may be permitted to
refer to the splendid results obtained by my late
brother, Wilson W. Phipson, M.Inst.C.R, of London, to
whose marvellous energy and indefatigable labours
ending, alas! in premature death most of the largest
public buildings in Great Britain owe their superiority
in this respect, notably the Eoyal Albert Hall, the
Banks and Clubs of London, the Universities and
Medical Schools of Glasgow, Edinburgh, Liverpool,
1 Thomson, A System of Chemistry (in four vols.), London, 1820.
F
82 THE EARTH'S ATMOSPHERE.
Birmingham, etc., all works obtained in public com-
petition. His method is described in an excellent
paper read to the Institution of Civil Engineers, and
published in their Journal. 1 The application of air in
motion to chemical industries, such as getting rid of
acid vapours in gold refining, and chemical laboratories,
etc., was also carried out most successfully by him for
Baron Eothschild, and for the professors at the Glasgow
and Edinburgh Universities, as well as in many other
cases.
The great Swiss engineer, Daniel Colladon, who has
recently departed from among us at 91 years of age, has
also left an imperishable name, by his talented applica-
tion of compressed air for the boring, and ventilation, of
tunnels and mines. His blowing machines, worked by
hydraulic pressure, by which the Mont Cenis and St.
Gothard tunnels through the Alps were bored, were
already under consideration as early as 1852.
The air-gun is one of the oldest applications of
compressed air (1650); and the briquet a air, by which
a lighted tinder is produced, by sudden compression,
as I have already mentioned, dates back about two
centuries.
Great economy would be realized if compressed air
could be used in place of steam for locomotion. Some
attempts have been made in this direction; among
others, one by the French inventor, M. Julienne, about
1 Wilson W. Phipson, Journ. of the Inst. of Civil Engineers,
London, 1878-79. For a notice of his career, see the same Journal
1892.
THERAPEUTIC ASPECTS DISINFECTION. 83
the year 1852 or 1853, when the Swiss engineer just
named first thought of his; and, also, by means of
the hydraulic press. But neither compressed air, nor
heated air (machines of Ericsson, etc.), nor electricity,
have, up to the present time, been made to compete
successfully with steam. In the case of such machines
as that of Julienne, steam or some other motive power
must be used to work the hydraulic press.
Air itself is the motor power in the windmill ; and
an ingenious apparatus of this description, known as
the " Kollaston wind motor," is at present being experi-
mented with in the neighbourhood of London, with the
view of applying it to electric lighting by wind power.
With regard to the use of compressed or rarefied air
as a therapeutic agent, Dr. Junod, a Swiss physician,
whom I met in Paris in 1856, had invented in the early
part of the century a metallic boot, coming up beyond
the knee, where it was fixed by an air-tight bandage.
A small tube near the foot, or ankle of the boot,
allowed the air to be extracted by means of a small
air-pump. This apparatus was used in cerebral con-
gestion, etc., with apparently good results. The last
occasion that came under my notice was in the case of
the celebrated chemist, Eegnault, after his fall through
the skylight at the Porcelain works at Sevres, of which
he was then director. By the production of a vacuum
in the boot, Dr. Junod hoped to withdraw the blood
from the congested parts (head, lungs, abdomen) into the
leg, and so relieve the congestion. The apparatus was,
in fact, an extension of the dry cupping-glass.
84 THE EARTH'S ATMOSPHERE.
Paul Berfc, many years later, drew attention to his
experiments with compressed oxygen ; and it was hoped,
at one time, that they would lead to a method of curing
phthisis, anaemia, asthma, etc. At the present day,
there are to be found in Paris, Berlin, and other cities,
one or two establishments where air-laths, or oxygen
baths, at various degrees of pressure, are in operation.
Although I have no personal experience of these
applications yet, having been for the last fifteen years
on the staff of two medical journals, it has been my
duty to record, from time to time, any progress that
has been made in this direction. The latest researches
on the subject are embodied in the observations of
Dr. Brugelman, of Berlin, who, after a lengthened
experience, has come to the conclusion that compressed
air is a better remedial agent than compressed oxygen.
He declares that it produces excellent results in the
treatment of asthma, emphysema, bronchial catarrh,
chlorosis (anaemia), pleurisy, and valvular disease of the
heart. He has reported two cases of chlorosis in which
much benefit followed the compressed air treatment.
Emphysema he found most benefitted by rarefied
air.
It must be remarked, however, that this kind of
treatment has not yet gained the suffrages of the
generality of practitioners.
Quite recently, the compressed air lath has been used
by Dr. Hovent, of Brussels, in the treatment of deafness
in a girl 13 \ years of age, who had gradually become
deaf, from birth, and had undergone several operations
THERAPEUTIC ASPECTS DISINFECTION. 85
with little or no benefit. The compressed air bath is
said to have cured this case in about a fortnight, which
is, certainly, very remarkable.
Another very important subject is the disinfection of
air impregnated with the germs of disease.
The best general disinfectant of the air appears to be
chlorine gas acting in daylight ; then come bromine and
iodine vapours, also sulphurous acid, obtained by burn-
ing sulphur, which is often used for disinfecting the
wards of the Paris hospitals. 1
The most powerful disinfectant of the air, among
organic substances, is the essence of cinnamon] then
come essence of cloves, essence of turpentine, carbolic
acid, thymol (essence of thyme), menthol (essence of
mint), salicylol, eucalyptol (essence of Eucalyptus), and
camphor.
The essential oil of cinnamon sprayed into the air
of a hospital ward where malarial fever raged, has been
found to hasten the cure of the patients, and to check
the spread of the disease very promptly. Unfortunately
it is rather expensive.
I have found chlorine gas (obtained by pouring
dilute hydrochloric acid on to chloride of lime) arrest
the spread of scarlatina and small-pox, in a very remark-
able manner, on more than one occasion.^
Eucalyptol vapour is said to arrest the spread of
influenza, and menthol vapour, sniffed violently into
the nostrils at frequent intervals until warmth is felt
1 See my Health Notes and Curiosities of Medical Science, London,
1898, p. 24 et seq.
86 THE EARTH'S ATMOSPHERE.
in the throat, will arrest coryza, or " cold in the head,"
in a few hours.
But I have observed that certain disinfectants have
a special action on certain disease germs ; thus, essence
of cinnamon appears most effective in malaria, essence
of mint for consumption, essence of eucalyptus for in-
fluenza, etc. These are facts which are only now
coming to light for the first time, and require careful
investigation.
That the most terrible diseases, such as cholera,
tuberculosis, diphtheria, scarlatina, small-pox, and
traumatic fever, not excepting puerperal fever, can
be mitigated, and perhaps prevented altogether, by
thoroughly disinfecting the air of a locality, is now
beyond doubt. The rapidly diminishing incidence of
cholera among the protected communities of Bengal,
is a striking proof of the capabilities of modern sanitary
science in this respect, no less than are the marvellous
results yielded by surgical antisepsis during operations.
According to Dr. Cortes there are no pathogenic
microbes, or disease germs, in the atmosphere of Cape
Horn. The Fuegians did not know anything of small-
pox, measles, scarlatina, or diphtheria, before the
inroads of civilization. Prior to the visits of the
missionaries, even pulmonary consumption was un-
known, and tuberculosis has only begun to establish
itself since the year 1881.
Dr. Contsand has made a study of the atmosphere of
the Arctic regions as regards its contents in bacteria
(microbes, disease germs). An examination of the
THERAPEUTIC ASPECTS DISINFECTION. 87
air, the water, and the soil of Spitzbergen brought
to light the extraordinary poverty of these regions
in bacteria. Whilst Dr. Miguel found in the streets
of Paris an average of 51,000 bacteria in the cubic
yard of air, the air of the Arctic seas contained only 3.
In the water of Spitzbergen no microbes of any kind
were found. A few were detected, however, in the
water of the island of Jan Mayen. The Bacillus
subtilis, so commonly met with in the different countries
of Europe, was not to be found in the soil of these
Arctic regions.
These remarks will, doubtless, be found to apply
with equal force to many other localities, hitherto
unexamined.
Some places have been noted as " health resorts/ 1
the atmosphere being remarkably pure there, neither
too hot nor too cold, with no sudden oscillations of
temperature, and the degree of moisture being likewise
moderate. Among other places, Southern California
has of late years been much extolled in this respect.
It is claimed that there is to be found the ideal climate
of the celebrated German physician and author,
Hufeland. Photographs have been taken of Indians,
whose great age appears to confirm the popular legend
that in Southern California and Arizona the aboriginals
never die " they just dry up, and &re wafted away
by the wind."
A few years ago, General G. M. Kober pointed out
that if inorganic dust can travel through the atmosphere
to such immense distances (as was noticed, for instance,
88 THE EARTH'S ATMOSPHERE.
in the case of the volcanic ash of Krakatoa), there is no
reason why disease germs should not be wafted by the
air to still greater distances. But the sea air appears
to destroy them : the distance to which infectious microbes
have been carried out to sea, as far as actual experience
has hitherto gone, is under 120 nautical miles.
CHAPTER XIV.
Air of Inhabited Districts, of the Country, of the Sea-coast, and
of the Ocean Quantity of Carbon in the Air of a London
Music Hall Quantity of Carbon in the Earth's Atmosphere
Quantity of Carbon in Organized Beings The New Gas
" Argon n Forest Air The Author's Observations in
Waldeck, etc. The Influence of Trees on the Air of Towns
Influence of Forests on Rainfall known to Columbus The
Author's Explanation based on direct Observation.
THE term Atmosphere should, properly, be applied only
to the gaseous envelope of the Earth ; whilst the term
air is used to denote a limited portion of the atmos-
phere, such as the lower portion in which we live, the
air of rooms, of mines, of forests, the air of the sea, etc.
Ordinary air, in inhabited districts, yields to analysis,
in round numbers, 21 volumes of oxygen and 79 of
nitrogen', it contains, on an average, 4 volumes of
carbonic acid in 10,000 volumes of air, and in the open
country this amount will fall as low as 3 parts in
10,000, whilst over the ocean, according to Beauvais,
there is a mere trace of this gas in the air, a fact,
doubtless, to be accounted for by the solubility of
carbonic acid in water.
My late distinguished friend, Dr. Verhaeghe, of
90 THE EARTH'S A TMOSPHERE.
Ostend (Belgium), found only 2-|- parts of carbonic acid
in 100,000 volumes of air on the coast, which is more
than 10 times less than is found in inland districts.
As carbonic acid is known to be very deleterious to
consumptive patients, its almost complete absence over
the waters of the ocean is one of the reasons that
has caused physicians to recommend sea- voyages for
sufferers of this kind.
Although the relative amount of carbonic acid in the
air appears, at first sight, to be exceedingly small, its
absolute amount in the whole atmosphere is exceedingly
great. Let us take the average contents of the atmos-
phere in carbonic acid at 4 parts in 10,000. A room
25 feet long, 25 feet broad, and 16 feet high, would
hold 10,000 cubic feet of air, with its 4 cubic feet of
carbonic acid ; and these 4 cubic feet of this gas would
weigh 2455 grains and contain 607 grains of carbon
(equal to a piece of charcoal about the size of a hen's
egg)-
A large music hall in London contains about 150,000
cubic feet of air, and consequently, the amount of
carbonic acid contained in it will be 15 times 4, or 60
cubic feet, and the amount of carbon 15 times 607
grains, or more than 1| Ibs.
When we pass from the consideration of the air, in
rooms, large or small, to that of the Earth's atmosphere
in its present condition, we get results almost beyond
conception :
The weight of the air overlying every square inch of
the Earth's surface is in round numbers about 15 Ibs.,
CARBONIC ACID OZONE FORESTS. 91
or 2160 Ibs. on the square foot. So that every square
foot of the Earth's surface has overlying it 2160 Ibs. of
air; and this quantity of air contains about \\ Ibs. of
carbonic acid, equivalent to nearly ^ Ib. of carbon.
The organized beings on the Earth's surface contain
on an average 45 per cent, of carbon (nearly half their
weight), and from a single acre of wheat land, some
2000 Ibs. of carbon are taken in a single season. Now,
if we reckon from acres to feet, we find that, during the
whole period of its growth, this crop of wheat, which
yields 2000 Ibs. of carbon, has overlying it some 20,000
Ibs. of carbon in the form of atmospheric carbonic acid,
which is infinitely in excess of the wants of vegetation
in this respect ; and the quantity of carbon in the entire
atmosphere, as carbonic acid, is far in excess of that
contained in all living beings, both plants and animals,
existing on the surface of the Earth, and in the in-
flammable carbonaceous minerals, such as coal, lignite,
peat, etc., which lie buried beneath its surface, as far
as we can estimate this quantity with any degree of
probability.
The supposed new gas in the atmosphere, which has
recently been brought before the public by Lord
Eayleigh and Professor Eamsay, who have given to it
the name of " Argon " (inert) on account of its abso-
lutely inert properties, and which, 'they say, forms
about 1 per cent, of atmospheric air, appears to several
chemists to be an allotropic form of nitrogen, similar to
what ozone is to oxygen ; or a protocarlide of nitrogen.
It remains as a residue when a mixture of oxygen and
92 THE EARTH'S ATMOSPHERE.
nitrogen is submitted to a long series of electric sparks,
until no more nitric acid can be formed in this way.
This inert residue was observed by Cavendish, who
first made this experiment, in the last century It
weighs rather more than ordinary nitrogen, just as
ozone is denser than oxygen. It is not absorbed by
red-hot magnesium, as ordinary nitrogen is ; and the
figures given in the author's paper, read to the Eoyal
Society, point to the probability of its being 3 molecules
of nitrogen condensed into 2 molecules, similar to
what the late Dr. Andrews of Belfast found to be the
case with ozone, as regards oxygen. Lord Eayleigh
had noticed that the nitrogen gas obtained from
ammonia, or from nitric acid, weighed slightly less
than the nitrogen obtained from the atmosphere, and
this caused him to believe that the atmosphere con-
tained some unknown constituent which increased the
height of its nitrogen. This led to a series of very
laborious researches, in which he was assisted by Pro-
fessor Ramsay, and ended in the discovery of the
gaseous substance they call " argon."
When oxygen takes the allotropic form of ozone, its
characteristic properties are enhanced, its tendency to
combine with other bodies is much greater, its activity
is wonderfully increased. In the case of nitrogen,
when it passes into the state of argon, its inert nature
becomes even more apparent than it usually is, which
is exactly what we should expect. 1 Argon may, never-
" } See Phipson, Cfomical News, February 1895, and Berthelot,
Comptes-rendus, llth March 1895.
CARBONIC ACID OZONE FORESTS. 93
theless, prove to be a carbide of nitrogen containing
half as much carbon as cyanogen, which would have
the same density.
The beneficial influence of forest air has often been
ascribed to a large amount of oxygen, less carbonic
acid, and the presence of balsamic, aromatic vapours.
But analysis shows that there is very little, if any,
extra oxygen during the day, and rather more carbonic
acid at night, than in the open air of the country.
The wind constantly tends to mix the forest air with
that of the fields and plains, and the hygienic influence
of the former must be ascribed in great measure to its
freedom from dust and disease germs. It is, so to say,
filtered air.
The diurnal variations of temperature are also slighter
in forests than in the open country. Woods are usually
warmer than the adjacent atmosphere. I have noticed
that the forests on the hills of Waldeck, in Germany,
appear to smoke, after heavy rain in June, an effect due
to the moisture rising with the warm air of the woods
into the cooler atmosphere above them. I have seen
the same effect on a garden wall in London, which
being heated by the summer sun for some hours,
emitted steam after a heavy shower of rain.
Once in a hot crowded room in Paris, I witnessed
a similar condensation of invisible moisture into visible
steam, from a reverse process. It occurred over plates
of ice handed to the guests : each ice appeared to smoke,
like a miniature volcano, producing a most singular
effect.
94 THE EARTH'S ATMOSPHERE.
The air immediately over the tree tops, and at the
edge of a forest, has been found to contain more ozones
than in the interior of the woods, where any ozone
would be at once absorbed by decaying leaves and
branches.
Investigations of cholera and yellow fever epidemics
have lately demonstrated that disease germs always
avoid towns and villages surrounded by forests ; and
that after the clearing of forest lands, these epidemics
appear in localities which, previously, had never been
visited by them. 1
The influence, of trees on the atmosphere of towns has
lately been examined by Dr. Jeannel. The problem
may be solved, he says, in the following manner : The
carbon converted into carbonic acid by one man, per
annum, is about 1400 Ibs. The carbon absorbed, per
annum, as carbonic acid, by an acre of forest is approxi-
mately 8050 Ibs. It results from this, that trees
planted in towns can have but little influence on the
purification of the air denied by animal respiration;
for, according to these figures, it would require some
300,000 acres of forest to absorb the carbonic acid pro-
duced in a year by a city which has a population of
two millions of inhabitants.
How, then, does it happen that the air of Paris, for
instance, which has been so often analysed, always
shows as nearly as possible the same composition :
oxygen 21, nitrogen 79 ?
It is the movement of the atmosphere, which wafts
1 Ann. of the Universal Med. Sciences, 1894.
CARBONIC ACID OZONE FORESTS. 95
away the carbonic acid to the vast forest tracts of the
globe the grand ventilation of Nature ; so that the
atmosphere, as a whole, gets back, volume for volume,
as oxygen, all the carbonic acid produced in densely-
crowded cities.
The influence of forests on rainfall, which was already
noticed in the days of Christopher Columbus, has been
so often written about that I need say little on this
subject. I have already alluded to the steam issuing
from the woods on the mountains of Waldeck after
heavy rain in summer, a phenomenon showing that the
atmosphere above the woods is cooler than the air in
their interior. I have also been struck by the rapid
manner in which the evenings cool after hot days in
these woody districts. The forests presenting a rough
surface radiate heat more rapidly than the smooth sur-
face of the open country. Thus, after very hot days in
June, when the thinnest cloth coat, or no coat at all,
was most acceptable, I found it necessary to put on an
overcoat some time before sunset.
This radiation, so marked from the rough surfaces of
forest lands, will readily account for the condensation of
more cloud, and consequently a greater rainfall in
wooded districts ; hence also increased fertility, and a
more prosperous condition of the inhabitants.
A well-known French hygienist traces the arrest in
the increase of population, and even depopulation, in
thirty departments of France to the disappearance of
forests in the mountainous districts.
CHAPTER XV.
Cold Air more dangerous than hot Air The late Dr. Meisser's
Opinion Effects of Sojourn in the Tropics Temperature
Observations Altitude, Dryness, Humidity Carbonic Acid
in London Fogs Air over Stagnant Water Hydrocarbon
Gases in the Air of certain Localities The Air of Mines-
Air of Bedrooms Air of Fermentation Air of Wells and
Sewers Air over active Volcanoes Air of Mountains
Effects of Arsenic Air of Treeless Plains Air of the Arctic
Regions, and that near the Snow-line on Mountain-slopes
Air of the Tropics Air in Epidemics of Cholera.
Cold air produces a higher death-rate than hot air, as
was professed in 1850 by the late Dr. Meisser, the dis-
tinguished Professor of Comparative Anatomy at the
University of Brussels, and his opinion was fully con-
firmed by Dr. Benjamin Ward Eichardson of London,
in 1890, or forty years later.
Meisser especially pointed out that cold was more
dangerous than heat to aged persons. The saturation
of the air with moisture increases the unfavourable
effects of a cold atmosphere. The danger from con-
sumption is much greater in winter than in summer.
With regard to hot air, it is known, at present, that
Europeans who have lived for some time in the tropics
are much less able to withstand the heat than are new-
AIR UNDER DIFFERENT CONDITIONS. 97
comers. The Anglo-Indian statistics supply us with
direct proof of the diminished vitality (or resisting
powers) of Europeans living for a long time in the
tropics.
The temperature of the air follows the course of the
sun ; it is coolest towards the break of day, just before
sunrise, and hottest about two or three in the afternoon.
To obtain a forecast for the day, it is necessary to
observe the thermometer always at the same hour, say at
nine o'clock in the morning. Its indications will then
serve to establish whether the day will be colder or
warmer than the preceding day.
In very variable weather the thermometer will
fluctuate considerably during the twenty- four hours,
both by day and by night, as cold or warm currents of
air affect it ; but such sudden changes are not common.
They are more frequently observed with us in England
during the cold winter weather, when the night tem-
perature is sometimes higher than the day temperature,
just as with a patient suffering from fever.
The air on a cloudy night is always warmer than it
is on a clear night when the Earth radiates its heat
into space. Clouds check this radiation. We cover up
plants to preserve them from cold on clear nights ; their
radiation often cools them down to freezing-point in
spring, and in summer causes them to bp covered with
dew. When the sky is overcast there is less danger from
frost, and no dew is deposited.
The temperature of the Earth's atmosphere is
evidently affected by the position of the planets. The
98 THE EA RTH'S A TMOSPHERE.
approach of Mars to the Earth in 1892, when it
appeared in the sky as brilliant as Jupiter, was followed
in 1893 by most intense heat at Bombay, New York,
London, etc., etc. (the law is that when bodies (or atoms)
approach, heat is the result, and when they move away
from each other cold results). The going away of
Mars was probably the chief cause of the intense and
prolonged winter of 1894-95, which will be long
remembered in London (especially by the Water Com-
panies), and in the South of France and northern Italy,
where its effects were first felt.
The cold days of May (about the 10th to 12th) are
most probably to be ascribed to the interposition at this
period between the Sun and the Earth, of the November
meteor streams (13th and 14th); to the melting of snow
and ice on the mountains, by which enormous amounts
of atmospheric heat are absorbed, and to the presence of
floating icebergs in the Atlantic.
With regard to altitude in the atmosphere, it has
recently been found in India that 7000 feet is about
the best height for a permanent residence for Europeans,
5000 feet being the lowest level at which malarial fever
can be avoided.
In South America yellow fever breaks out only in
localities where the temperature reaches to 70Fahr. and
above. At elevations where this temperature of 70 is
never exceeded, the inhabitants are almost exempt from
this terrible epidemic.
Dryness of the atmosphere,, with liability to dust, cold,
fogs, winds, and rapid fluctuations of temperature, con-
AIR UNDER DIFFERENT CONDITIONS. 99
stitutes a very bad climate for most invalids. The
chief reasons why sea air is so conducive to health
reside in its greater humidity ; greater purity as
regards carbonic acid and animal effluviae; greater
density, whereby the lungs take in a rather larger
amount of oxygen at each inspiration ; and, generally, a
larger amount of ozone. A modern American writer, Dr.
Baruch, is enthusiastic on the value of pure air for con-
sumptives, when this purity is combined with conditions
which afford the best opportunities for an out-door life.
On the summit or higher slopes of a mountain, there
is less carbonic acid in a cloud or fog than is found
in the air of the same locality in fine, clear weather.
This is a curious and interesting fact, since the very
reverse is found to be the case in large towns. For
instance, when the streets of London are obscured by a
dense fog, the quantity of carbonic acid in our atmos-
phere is greatly increased; this gas appears to be
absorbed by the fog, and its diffusion through foggy
air is much less rapid than through clear air.
Dogs that fall senseless in the Gfrotta del Cane, near
Naples, from the effects of carbonic acid that oozes
from the soil, soon recover when placed in the pure
open air, and Dr. Marcet has lately shown that the
effects produced on the chemical phenomena of respira-
tion by breathing and re-breathing eight gallons of air
in a closed vessel for the space of five minutes, pass
away in less than six minutes after the breathing of
fresh air has been resumed.
Hence it is evident that persons who are called upon
ioo THE EARTH'S ATMOSPHERE.
to make a prolonged stay in ill-ventilated rooms, should
go into the open air as often as possible, if only for a
few minutes.
The air over stagnant waters in the country shows
large quantities of carburetted hydrogen (marsh gas), as
well as carbonic acid, due to the gradual decomposition
of vegetable matter in the mud. When this mud is
stirred up, abundance of this inflammable carburetted
hydrogen gas can be collected, as was first shown by
Campi of Milan, a learned ecclesiastic, and friend of the
celebrated Volta, about the year 1760. It often bubbles
up spontaneously, and can be set alight on the surface
of the water. It is probably the cause of the will-o'-
the-wisp, or Ignis fatuus, and is the same gas that
oozes from the seams of coal and gives rise to colliery
explosions. 1
In some countries in the East, and in America, this
carburetted gas burns permanently at the surface of the
soil, and has done so for a very long period of years.
But it should be remarked that, in some cases, the flame
is not due to marsh gas, but to some other hydrocarbon
of the naphtha or petroleum nature. It is always easy
to distinguish between the two, as marsh gas burns
without smoke and without odour, other hydrocarbon
gases producing both smoke and a more or less fragrant
odour.
The air of mines also shows the presence of this same
marsh gas, which oozes spontaneously from the seams of
1 See Phipson, Familiar Letters on some Mysteries of Nature, where
an entire chapter is devoted to the phenomena of the Ignis fatuus.
AIR UNDER DIFFERENT CONDITIONS. 101
coal, especially when the barometer falls rapidly after
having remained very high for some time ; and, when
fired, occasions the dreadful explosions of which we read
too often. The putrefaction of animal matter, such as
the bodies of dead dogs, which are not unfrequent in coal
mines, may give rise to ignis fatuus, and some of these
accidents may, perhaps, be thus accounted for. They
will continue to occur so long as mines are constructed
in such a manner as to render complete ventilation
impossible. Hitherto chemists have not discovered any
substance that will absorb, or destroy, this gas as fast as
it is produced. I once imagined that chloride of lime
might prove effective, but have had no opportunities of
making experiments on the subject.
The air of bedrooms is rendered unwholesome by
animal effluvise, but chiefly by carbonic acid. In the
bedrooms of consumptive patients small buckets of
hydrate of lime (slaked lime) should be placed, to absorb
the carbonic acid as it is produced; and should be
renewed every two or three weeks. The air may also
be disinfected by exposing on the chimney shelf a little
essence of peppermint, or of eucalyptus. The air of
hospital wards is best disinfected with sprays of essence
of cinnamon, or of eucalyptol, the odours of which are
agreeable. They are quite as antiseptic as carbolic acid,
which is highly poisonous, and has a disagreeable odour.
But, as I have already stated, every disinfectant has its
appropriate use ; some appear to act better than others
in certain given circumstances.
The air of fermentation which is found in wine vats
102 THE EARTH'S ATMOSPHERE.
and breweries is fatal to man, on account of the large
amount of carbonic acid it contains : it extinguishes a
lighted candle. Deaths have occurred, during vintage
time, by men incautiously coming under the influence
of this air. Being much heavier than ordinary atmos-
pheric air, it flows over the vats, like water, and forms a
thick layer on the floor of the shed or cellar. A small
quantity easily induces sleep, during which a workman
will succumb to its effects.
The air of wells and seivers is likewise dangerous to
workmen who enter it before depriving it of its
carbonic acid. This can be done by means of slaked
lime, or by forcing in fresh air, to displace the foul
air. The workman should assure himself that a candle
will burn brilliantly in this air before he descends.
Besides carbonic acid, the air of sewers often contains
sulphuretted hydrogen, and volatile organic compounds
of sulphur, which have been observed to be rapidly fatal
to rats; and sulphuretted hydrogen was once actually
used to destroy rats in the Paris sewers by the celebrated
chemist, Baron Thenard, in the early part of this century.
The air over active volcanoes contains sulphurous acid
and hydrochloric acid. It is extremely dangerous to
excursionists on Vesuvius when the wind happens to
turn in their direction. It was this air that killed
Pliny the Naturalist, in the year 79.
The air of the sea, as I have already mentioned, is
often impregnated with salt, especially during rough
weather, and in hurricanes with rain at Barbados, and
elsewhere, the rain is often salt.
AIR UNDER DIFFERENT CONDITIONS. 103
The air of the mountains, to which I have also alluded
above, is purer, freer from carbonic acid and moisture,
but less dense than that of the plains. It affects re-
spiration most painfully, especially when the sufferer
is fatigued, as less oxygen is taken in at each breath.
But, as we saw when I alluded to the interesting dis-
covery of Dr. Viault, the number of red corpuscles of
the blood is increased by a continued sojourn in moun-
tain air, so that, in time, hcematosis, or oxidation of the
venous blood, is carried on as usual. To promote this,
the Tyrolean mountaineers have recourse, sometimes, to
arsenic, as a tonic. This is a dangerous practice, giving ex-
cellent results at first, but when once the period of arseni-
cal poisoning is reached (which comes on very gradually
and insidiously) the patients are often beyond the reach of
medical art, and many have thus succumbed early in life.
The air of treeless plains, distant from inhabited
districts, is remarkable for its dryness, its density (if
these plains are not elevated), and its dust. The wind
gives rise to dust-storms (or sand-storms) over the
deserts of Sahara, Gobi, etc., which have been often
described in works on Meteorology.
If the plains are covered with grass, the air is pure
and healthy, and devoid of dust.
Heated air, which causes the phenomenon of the
mirage in the hot, sandy deserts, produces the same
curious effect in our own temperate climate, as I found
as early as 1856; 1 only, in this country, on our sea-
1 Journal La Science, Paris, 1856, and Comptes-rendus of the Paris
Academy, 1857.
104 THE EARTH'S ATMOSPHERE.
coasts, or long straight thoroughfares, we must sit down
upon the ground in order to place ourselves in the
layer of heated air that produces this curious effect.
Then men and animals at a distance appear much taller
than they should, according to the laws of perspective,
and their images are seen as if reflected in a sheet of
water. Several times have I witnessed this pheno-
menon during the hot days of summer on the sandy
coast of Flanders, and also in the neighbourhood of
London. 1
The air of the Arctic regions, and that which lies
above the snow-line on mountains, is dry and cold.
When not in motion man can support its effects in spite
of its exceedingly low temperature ; but when in motion
it cannot be resisted with impunity; and it is then
absolutely necessary to seek shelter, as was vividly
pointed out by the American Arctic explorer, Dr. Kane,
who succumbed not long after his return from his
arduous enterprise, and at a very early age. But there
is a certain difference between the air of the Arctic
regions and that of a corresponding latitude on the
slope of a mountain, which is indicated by the structure
of the plants which grow in these regions : When the
air of the Arctic regions is compared with that of a
1 The results of my meteorological observations on the coast of
Flanders were described to the Paris Academy of Sciences in 1857.
It was there (and afterwards in Paris, and again near London) that I
first witnessed the curious phenomenon of rain without clouds ; and, on
one or two occasions, frozen rain which fell in pear-shaped solid drops.
Once also, at Ostend, I was able to convince myself that lightning
occasionally occurs among clouds near the- zenith, without being
followed by the slightest noise of thunder. .:\^
AIR UNDER DIFFERENT CONDITIONS. 105
corresponding station on the Alps, the former is found
to contain much more moisture, and the leaves of the
same species of plant (Saxifrage, or Salix, for instance)
are invariably thicker than they are when growing in
the mountainous district.
The air of the Tropics is generally hot and moist ;
furniture and musical instruments become unglued,
and valuable violins have been known to fall to pieces
in India, and the West Indies, soon after their arrival
from Europe. I have already alluded to its effects upon
the health.
With regard to the air in cholera epidemics, Glaisher
and others have drawn attention to a peculiar Hue mist
which occurred in London and its neighbourhood during
such an epidemic; but nothing at all satisfactory was
the outcome of this observation. Early in the present
century, it was noted by Figari, then Professor of
Botany at Abuzabel, in Egypt, 1 that during the cholera
epidemic of July and August 1835, several kinds of
grasses, especially Maize (Indian Corn), were killed,
over large districts, by blight; and the peasants who
used the leaves of these plants for their cattle, or for
themselves, contracted severe illness in every case.
1 This gentleman published in 1867-8 an important paper on the
cultivation of the opium poppy in Egypt. See Ann. pharmaceutiqiw
de Reveil et Paris, etc., Paris, 1868, p. 330; Sur la Culture du Pavot &
Opium, etc., par Figari Bey.
CHAPTER XVI.
The Movements of the Atmosphere Barometer and Thermometer
Cause of their Ke verse Movements Expansion of Air
Diurnal Oscillations of the Atmosphere Fluctuations of the
Electric State of the Air Velocities of the Wind Cause of
the Movements of the Barometer English Weather
Cyclones History of Rotatory Storms Small Local Cyclones.
THE movements of the Atmosphere have been exten-
sively studied in modern times. We are far away from
the days of Howard and Wells, whose ingenious
observations laid the basis of the modern science of
Meteorology ; but only men like Fitz-Koy and Maury,
who have navigated the seas for many years, can hope
to grapple successfully with the Physical Geography of
the Atmosphere.
The prime cause of the great movements of the air
is heat, that mysterious power which, confusing itself
with light and electricity, may justly be termed the
soul of the Universe. The terrestrial sources of heat,
and that derived from solar radiation, are at present
nearly equalized, but the evaporation of water (which
forms about two-thirds of the Earth's surface), followed
by its condensation from steam to water, and to ice,
yielding up enormous amounts of latent heat, exhibits a
AERIAL CURRENTS. 107
constant, alternant source of production, and distribu-
tion, of cold and caloric, upon which depend the various
climates, the regular, periodic, and variable winds, the
zones of vegetation, the currents of the ocean, and, in
fact, the whole life of the globe.
The same mysterious power, called heat, or caloric,
which causes the circulation of the sap in plants, and
of the blood in animals, circulates also the air of the
Atmosphere, and the waters of the Earth, and keeps
them in constant motion ; for, as I said many years ago
in a former work, " movement, like matter, is universal" l
The vane makes its rotation, in our hemisphere, in
the same direction as the Sun, a fact which was per-
fectly well known in the most remote antiquity (see
Thales, and other ancient philosophers, quoted by Dove,
in his Law of Storms), and the reverse occurs in the
Southern hemisphere.
The warm wind and the cold wind (originating,
respectively, at the tropics and the poles) alternate
one with the other. When the warm wind displaces
the cold wind, the change commences in the higher
regions of the air, and the barometer falls before the
thermometer rises. When the cold wind takes the place
of the warm wind, the change occurs in the lower
strata of the air, and the thermometer falls before the
barometer rises.
When cold air descends into warm air, fog is pro-
duced ; the descending current beats down the smoke of
our cities, and disperses it over the surface of the Earth.
1 Phipson, Familiar Letters, etc., The movements of plants.
io8 THE EARTH'S ATMOSPHERE.
According to the very exact researches of Magnus, of
Berlin, on the expansion of air from 32 Fahr. to 212
Fahr., it follows that air at the freezing-point of water
expands 4^ T th part of its bulk for every degree of heat
of Fahrenheit's scale.
Thus, 491 cubic inches of air at 32 Fahr., become 492
at 33, 493 at 34, and so on, increasing one cubic inch
for every degree Fahrenheit.
A contraction of one cubic inch occurs for every
degree below 32. Thus, 491 cubic inches at 32
become 490 at 31, 489 at 30, 488 at 29, and so on.
This shows that atmospheric air taken at the freezing-
point of water has its volume doubled at 491 Fahr. ;
and when heated up to 982 Fahr. (a low red heat) its
volume is exactly tripled.
With regard to the diurnal oscillation of the atmosphere,
the following little table is universally admitted :
At 4 a.m. there occurs a first minimum of the barometer.
10 a.m. maximum (highest).
4 p.m. second minimum (lowest).
10 p.m. second maximum.
These regular oscillations of pressure are easiest per-
ceived at the sea-coast in the equatorial regions, where
they are regular enough to allow us to judge of the
hour without resorting to a watch. They are difficult
to put in evidence in our temperate regions, but it can
be done, and they appear, like the daily magnetic varia-
tion, to be intimately connected with the position of the
sun in the heavens.
The fluctuations of the electric state of the atmosphere,
AERIAL CURRENTS. 109
as denoted by the needle of the galvanometer-electro-
scope, are as follows :
At 2 a.m., minimum.
10 a.m., maximum.
2 p.m., second minimum.
10 p.m., second maximum.
These are average results for our temperate zones, and
they correspond with the dryness and moisture of the air
(dry air, bad conductor ; moist air, good conductor).
If we add together the angles of oscillation of the
galvanometer needle during the summer, we get 33 ;
and during the winter, 799.
The rapidity with which the air moves over the
surface of the Earth, according to circumstances, can
be determined by means of the anemometer, an instru-
ment now in daily use in the Observatories. In round
figures it may be put down as follows :
Wind scarcely perceptible, . . 1 yard per second.
Moderate wind, .... 2 yards per second.
Fresh breeze (spread out the sails), 6 .,
Stiff wind (best for windmills), . 7
Strong breeze (quick sailing), 9
Half a gale (take in top sails), . 12
Very strong wind, . . . 15
Impetuous wind, or gale, . . 20 .
Very heavy gale, . . . . 27
Hurricane, . . . . . 36
Furious hurricane (overturning
buildings, etc.), . . . 45
no THE EARTH'S ATMOSPHERE.
A wind with a velocity of forty yards a second will
produce the most prodigious effects, carrying before it
all kinds of solid materials, such as tiles, bricks, beams,
stones, and even iron, to a considerable distance.
In 1715, the Academy of Bordeaux offered a prize
for the determination of the cause of the movements of the
barometer. It was awarded to M. 0. de Mairan, of
Beziers, who corroborated the opinions of the English
observers, Hawksbee and Halley, namely, that the chief
cause of these movements was the wind. This was estab-
lished on the principle that we must distinguish
between the absolute weight and the relative weight
of a body. The absolute weight (or pressure) cannot
be altered except by an addition, or subtraction, of sub-
stance ; but the relative weight may vary without any
change in the absolute weight ; and it is on this change
in the relative weight that the movement of the baro-
meter depends : When the atmosphere is in a state of
repose it presses upon the Earth with its whole absolute
weight, but when it moves it only presses by its relative
weight. Thus a ball that rolls on a flat table weighs,
or presses, less than when it is quiet.
This opinion is now generally adopted, though it was,
at first, objected to by some philosophers.
We should add, for our English climate, that north
winds, bringing heavier air than south winds (on
account of the greater moisture in the latter, and
because the air of the former is colder and denser),
invariably raise the barometer.
Barometric observations, carried on simultaneously
AERIAL CURRENTS. in
in the principal towns of Europe, have led to the
discovery of a curious phenomenon, namely, a vast
wave of high pressure, followed by one of minimum
pressure,, which traverses the whole of Europe, from the
English coasts to those of the Black Sea, in the space
of four days. They are real waves, like those of the
ocean, which, according to Professor Jamin, 1 flow
regularly across the Continent, from West to East.
The wave of low pressure brings tempestuous weather,
of which notice can be given beforehand by telegraph.
It has been long known that our English weather
comes chiefly from the West, that is, from the Atlantic.
It is to the predominance of the westerly winds that
we owe the best qualities of our climate. But besides
these genial and refreshing breezes, wafting their
warmth and moisture, and ozone, beneficial alike to
men, animals, and plants, we are visited occasionally
by gales, or storms of wind and rain, as disastrous to
crops and shipping as the milder airs are agreeable.
Many years have elapsed since it was first imagined
that these heavy gales of wind and rain might be
circulating, travelling storms. It was De Foe, the
author of Robinson Crusoe and a considerable number
of other works, who in 1704, in his essay on The Storm
(where special allusion is made to that of 1703), was
the first to suggest this. His observation has cul-
minated in the discovery of the nature and probable
origin of cyclones, or rotatory storms, which travel
across the Atlantic and visit our European shores at
1 Cours de Physique, second edition, vol. i. p. 259.
iii THE EARTH'S ATMOSPHERE.
certain intervals. We may show in a few words on
what data the practical warnings now issued are
based.
Winds are due to Solar heat affecting various
portions of the Earth's surface in an unequal manner,
and they are affected by the rotation of the Earth,
which deflects the currents of air produced by this
unequal distribution of temperature. But besides the
regular winds ("trade winds"), which navigators have
long ago learned to take advantage of, there is produced,
frequently, in the regions comprised between the
equator and the tropics, a translation of vast masses
of air, having a rapid rotatory motion around a central
axis. This axis is never precisely vertical, and whilst
the air circulates around it, the entire mass is trans-
ported in a given direction, forming what is termed a
cyclone. The direction of the rotation is tolerably
constant : in the Northern hemisphere, it is the reverse
of the motion of the hands of a watch the wind blows
or circulates from East to West through the North.
In the Southern hemisphere, the contrary occurs : the
wind blows round from East to West, by South, that
is, the rotation is in the same direction as that taken
by the hands of a watch.
These cyclones constitute the great tropical storms
called hurricanes, or typhoons ; they are the more
severe, generally speaking, the smaller their diameter.
At their origin, this diameter is comparatively small,
but increases as the cyclone travels away from the
locality of its birth. Thus, some cyclones which had,
AERIAL CURRENTS. 113
at starting, a diameter of about 180 miles, end in attain-
ing a breadth of 1500 miles.
The central portion of the cyclone is relatively calm ;
the maximum velocity of the air is found at a certain
distance from this centre, beyond which it again
diminishes gradually in force. In certain points of
the cyclone the wind is very violent, and in some
instances has been known to blow at the rate of
upwards of 120 miles an hour.
The rate at which a cyclone travels from one part of
the ocean to another appears to vary very little in the
same quarter of the globe. From the American shores
to Europe, it almost always progresses at the rate
of about thirty miles an hour ; so that we can calculate
approximately the time which a cyclone will take to
reach Europe, after it has left the American coasts.
The curve which, on a Chart of the World, would
represent the course of the central point of the cyclone,
has its concavity usually turned towards the east.
Every cyclone that travels thus across the ocean, has
one side, one half-circle, in which the wind is more
violent than on the other. This is termed the
" dangerous side," because ships are more exposed
there than in other parts. If we suppose an observer
travelling in the same direction as the central point,
the dangerous side is always on his right hand in the
northern hemisphere. This is natural, because on this
side of the cyclone the direction of the wind in its
rotation and that of its progression are the same, and
consequently add to each other. On the opposite side,
H4 THE EARTH'S ATMOSPHERE.
the wind rotates in a contrary direction to the pro-
gressive motion, and the latter, therefore, diminishes
the intensity of the former.
One of the consequences of this rotation of the air
around a central space, is to produce a rarefaction
or diminution of pressure, in the latter region, so that
in this central part of the cyclone the barometer falls
very low. The course followed by this depression
(lowest barometer) is that of the cyclone.
The data collected by vessels crossing the Atlantic,
compared carefully with those supplied by the various
meteorological stations in Europe, point more and
more to the truth of the old opinion that the Gulf
Stream is the "parent of tempests" of the Atlantic
and its coasts. Its comparatively high temperature,
the abundant moisture of the air above it, the opposite
winds blowing towards its course, all help to make it
the theatre of frequent atmospheric perturbations.
The aerial current which reigns above the Gulf Stream
naturally flows towards the east, in the direction of
Europe.
Besides these larger commotions that travel so
far, it is now admitted that small local cyclones are
occasionally formed in our latitudes, by the sudden
combination of a northerly and southerly current.
Such was the case in September 1876, when a minute
storm of this description produced such havoc at Cowes,
in the Isle of Wight. The author was at Bournemouth
at the time and experienced nothing. Again, in 1878,
a similar occurrence took place when the Eurydice
AERIAL CURRENTS. 115
was lost in the English Channel. It may also be
recalled that on the 25th and 26th October 1859,
when the Royal Charter was lost, the gale appears to
have commenced in the Bay of Biscay and terminated
in the Baltic.
The whole question of cyclones is, however, far less
simple than this brief sketch might lead my readers to
suppose. It has been ably grappled with by Dove, of
Berlin, who began his investigations as early as 1827,
and his most recent work, the Law of Storms, embodies
his views on this important subject. 1
1 The Law of Storms, by H. W. Dove, translated into English by
Robert Scott, M.A. My copy of this important work was presented
to me by the late Admiral Fitz-Roy, F.R.S., together with his interest-
ing work, The Weather Book, a manual of practical meteorology ,
second edition, 1863.
CHAPTEE XVII.
Absolute Weight of the Earth's Atmosphere Various Optical
Phenomena caused by the Air The greatest height Man
has reached on Foot The Snow-line and Kegion of
Perpetual Ice.
absolute weight of the Atmosphere is a very simple
problem, though it has long been considered one of
the most extraordinary achievements of modern science.
The mercury, in a barometer, standing at 30 inches,
can be poured out of the tube into a balance and
weighed. This weight is that of a column of air, of
equal basis to the column of mercury. If the basis
of the column of mercury is equivalent, say, to* one
square inch, the weight of the metal in the tube will
be about 15 Ibs.
If we can find how many square inches cover the
surface of the globe and multiply them by 15 Ibs., the
result will be the entire or absolute weight of the Earth's
atmosphere.
In this manner a great astronomer and geographer
(Francoeur) found that the weight of the entire
atmosphere, in tons, is represented by the figure:
523,260,000,000,000 tons.
ALTITUDE RE FRA CTIONSNO W-LINE. 1 1 7
We have already touched upon this subject when
alluding, in a previous section, to the absolute amount
of carbonic acid in the Earth's atmosphere.
The various optical phenomena presented by our
atmosphere are so fully described in works on Physics,
and Meteorology, that only a few words need be
devoted here to this portion of our subject. As we
have already said, the atmosphere is transparent and
invisible, except when seen through an immense thick-
ness ; it is then blue, the colour of the pure sky.
The presence of much moisture lightens this tint, so
that it becomes grey. As we rise in the pure air, the
vault of heaven becomes of a darker and darker blue,
almost black, and the stars become visible, as they
do when the sky is viewed from the bottom of a
deep pit.
The average refraction of light passing through the
entire thickness of the atmosphere causes the sun to be
seen for eight minutes after it has set, and eight minutes
before it actually rises, so prolonging our day by six-
teen minutes at all seasons of the year. In some states
of the air, refraction also distorts the figure of the sun
near the horizon. It is not, as many have thought,
the cause of the apparently increased size of the full
moon near the horizon. This is an effect of contrast,
f
caused by viewing the moon in comparison with
objects on the Earth's surface ; and if viewed through
a narrow tube of cardboard, so as to shut out these
objects, it appears of the same size as when seen at
the zenith.
1 1 8 THE EARTH'S A TMOSPHERE.
To refraction of light is also due, as we have already
said, the curious phenomenon of the mirage, the pris-
matic colours of the rainbow, of the solar and lunar
halos, and of the sky at sunset and sunrise. Another
optical effect that used to be much talked about, is
the so-called Spectre of the Brocken that is, the magni-
fied images of travellers standing at sunrise on the
summits of the Hartz mountains, their shadows being
thrown upon the mist or clouds by the rising sun at
their backs. I have often seen this phenomenon in the
neighbourhood of London, at night, when the light from
a lamp upon a table at the back of the observer throws
his magnified shadow through an open window upon
a dense fog.
The electric glows, or phosphorescence of rain-drops,
in thundery weather, which have been witnessed on
several occasions at Geneva and other places, the light
which sometimes issues from the summit of the masts
of a vessel (St. Elmo's fire), or from the hats of
pedestrians during a thunderstorm, the glow of the
Aurora borealis, during which the magnetic needle
is disturbed, and a number of other curious emissions
of light, often connected with electric perturbations
of the atmosphere, have been fully described by me
in other works. 1
1 Phipson, Familiar Letters on some Mysteries of Nature, London,
1876 ; Phosphorescence, or the Emission of Light ~by Minerals, Plants,
and Animals, London, 1862. (A spurious edition of this work was
issued without the author's knowledge in 1870.) Noctilucine (pam-
phlet), London, 1875. " Phenomenes lumineux, etc.," Comptes-rendus,
Paris, 1868.
AL TITUDEREFRA CTIONSNO W-LINE. 1 1 9
The greatest height to which anyone has travelled
on foot into the atmosphere, was that reached, some
years ago, by the brothers (Herman, Adolph, and Eobert)
Schlagintweit, namely, 21,000 feet, on the 20th August
1856, on the Abi-Gumin, one of the highest summits
of the Himalayas. 1 Their barometer stood there at
about 15 inches; they had, therefore, only half the
ordinary weight of the air to support (say 7|, instead
of 15 Ibs., to the square inch). Headache, difficulty of
breathing, spitting of blood, irritation of the lungs,
and great lassitude, were experienced. These symptoms
gave way as soon as they reached lower ground. These
travellers, like Dr. Kane in the Arctic regions, suffered
less from the cold than from the wind; and they
generally felt better in the morning than in the even-
ing. Muscular action induced immense fatigue; even
the act of speaking was fatiguing, and the lassitude was
such that they could have fallen down and gone to
sleep, for ever, upon the snow, had not supreme moral
courage vanquished this great physical weakness.
Water, in the form of steam or vapour, which always
exists to a certain amount in the atmosphere near the
Earth's surface, is, as we said before, thrown out in the
shape of cloud, or mist, as the air becomes colder.
Now, as cold increases with the altitude, the vapour
thus thrown out, and rendered visible* where, before, it
was invisible and only to be detected by our physical
instruments, or by chemical analysis, assumes the form
1 Some of our British troops have since been even higher than this,
in the recent border warfare in North-Western India.
120 THE EARTHS ATMOSPHERE.
of snow or ice at a certain elevation on the slopes of
high mountains. At a given altitude, which varies
according to a multitude of circumstances, we come
upon snow, or, as it is usually termed, perpetual snow,
corresponding to \k& perpetual ice of the Arctic regions.
The term snow-line has been given to indicate the
height which forms the lower limit on a mountain slope
at which this phenomenon occurs. But this is not a fixed
line at any given latitude, nor at any given point of the
globe ; it varies, by one to three thousand feet, according
to the "climate" of the locality. But, in any region
outside the Arctic zones, it is generally met with at
altitudes exceeding 10,000 or 12,000 feet. On the
volcano of Peuquenes (latitude 33 S.) it lies at about
15,000 feet; in the Himalayas at 12,000 to 13,000 feet;
in Thibet at 16,000 feet, and so on. 1
Alex, von Humboldt. who paid much attention to
this subject, calls attention to the interesting fact that
we are only acquainted with the lower (not the upper)
limit of perpetual snow ; for the mountains of the
Earth do not attain to those higher regions of rarefied
and dry air in which no water can possibly exist.
1 See Humboldt, Asie Centrale, vol. iii., for table of height of
perpetual snow in both hemispheres, from 71 N. to 58 S. lat.
CHAPTEE XVIII.
The Formation of Clouds The Vesicular Theory The Present
Theory Cirrus Cloud Cumulus Cloud Stratus Cloud
Nimbus Cloud Colour of Cloud and Sky as an Indication
of Weather Cause of Electric Phenomena in Thunderstorms
Formation of Snow and Hoar Frost Formation of Hail
Curious Phenomenon of the " Cloud -arch " First seen in
England by the Author Seen in Sicily by the poet Goethe
And in the Arctic Kegions by Sabine.
THE formation of clouds and their various aspects have
been the subject of a considerable amount of speculation.
The vapour of water is colourless, and is transparent
like the air in which it rises and diffuses: it rises,
because it is lighter than air (air = 1000, vapour = 623).
But if the air is a few degrees colder than the vapour,
the latter at once becomes visible, and takes a certain
form. 1
1 This sometimes occurs so suddenly that I remember, one evening,
in Paris, the celebrated M. Babinet, member of the Institute and
Bureau des Longitudes, who was a neighbour of mine, came to my
rooms and brought me out on to the Place St. Sulpice to witness the
variation in brightness of the star Algol, which is still a mystery to
astronomers, when, just as we had succeeded in finding it, the sky
became suddenly overcast with large mottled clouds, over the whole
heavens. A clearing of the sky of equal rapidity is never witnessed,
so that clouds can be formed by precipitation much more rapidly than
122 THE EARTH'S ATMOSPHERE.
What then happens ? Theodore de Saussure, and
the older naturalists, asserted that the microscope
solved this question ; that the ingredients of clouds are
minute vesicles of water filled with air, like the most
minute soap bubbles it is possible to imagine. This
was termed vesicular vapour ; and when these little
vesicles burst, they are converted into drops of rain.
Modern naturalists do not admit this "vesicular
theory " ; they contend that the water of the clouds is
in the state of extremely minute drops which, when
they coalesce, form larger drops that fall as rain. The
minute drops remain suspended, just like certain
powders, which are considerably heavier than water,
will remain for a long time suspended in that liquid.
In the highest regions of the air these minute drops
become frozen, and form tiny crystals of ice, which also
remain suspended in the air for a length of time, as
does volcanic dust, to which allusion has already been
made.
The cirrus clouds, which appear like long wisps
("mares' tails"), at a great height in the air, are formed
of these minute ice crystals. Although they usually
appear motionless to persons on the flat lowlands, to
those on the summit of a high mountain their move-
ment becomes apparent, and they may be seen to travel
with considerable, speed. They are often six or seven
they can be dispersed by absorption or dissolution in the air. And
this is just what occurs in the chemical laboratory, when a precipitate is
formed instantaneously ; but its re-dissolution is always much more
gradual.
CLOUDS. \ * oP
thousand yards high, and generally mctfeafe iT'CrTange of
weather : their presence in the atmosphere, after several
days of fine weather in Spring, Summer, or Autumn,
announces rain within twenty -four hours; and this
sign rarely fails. During the winter, if the weather be
mild, they announce frost; but if cold, they indicate
the approach of a thaw. The direction of their move-
ment is often opposite to that of any clouds that may
be seen beneath them.
The cumulus clouds are always lower ; they appear
at various heights, rising during the day as the heat of
the sun increases. They make their appearance in
Spring and Summer, and look like great bales of wool,
or like mountains. When the sun shines on them, they
resemble the snowy chains of the Alps, or the Pyrenees.
When they disperse in the evening, it indicates a fine
day for the morrow ; but if they increase in size, or
become more numerous at nightfall, and especially if
cirrus cloud is seen above them, we may expect rain, or
thunderstorms.
The stratus clouds form long, horizontal bands, often
very wide, seen about sunset, and sometimes most
gorgeously coloured. They disappear at sunrise, are
common in Autumn, and rare in Spring (but they
were very beautiful in London during the early part of
April 1895). They rise less high tharf the two kinds
of clouds previously mentioned.
Lastly, the nimbus, or rain-cloud, is usually of a
uniform dark grey colour, and massive, though without
any particular form.
124 THE EARTH'S ATMOSPHERE.
These four divisions, not being sufficient for the
classification of all forms of cloud, a few sub-divisions
have been made, such as the cirro-cumulus, small rounded
clouds spreading over a great portion of the sky, forming
what is called " mackerel sky," or a "mottled sky." The
French term is " del moutonne" as they often resemble
a vast flock of sheep. They generally indicate fine
weather, or heat.
The cumulo-stratus are cumulus clouds which have
become more numerous towards the end of the day, and
taken the character of the nimbus. They announce
rain. Cirro-stratus are, also, often a sign of rain ; they
form long filaments, more closely packed than the
ordinary stratus, and are not penetrated by the solar
rays. Near the horizon they appear black, or bluish-grey.
If clouds are white, and the sky between dark blue, it
is an indication that the drops of water are small, and
that the air around the cloud is dry. There will be no
rain. But if the clouds are grey and the intervals
between them dull, or very light blue, the drops are
larger, and the surrounding air damp. Eain will
probably follow.
The cloud does not usually resolve itself into rain
until the drops of water attain to a certain size. These
drops are the cause of coloured circles (not halos) round
the sun and moon. The smaller the drops, the wider is
the diameter of the circle. As the drops become larger
the circle gets smaller, and nearly touches the disc of the
sun or moon. Eain is then near at hand; but wider
circles often disperse without rain.
CLOUDS. 125
These coloured circles are more frequent than many
believe ; at night they are easily seen round the moon,
but by day they can rarely be seen round the sun,
unless the image of the latter be viewed on a sheet of
glass, one side of ivhich is blackened ~by smoke from a
lamp or candle. On misty mornings it is often possible
to say whether the day will be wet or fine, ~by inspection
of the width of the circle round the sun ; with drops that
increase in size the circle gets smaller, and vice versa.
The eminent Belgian meteorologist, Houzeau, says
that at the moment of condensation, that is, when the
invisible vapour is cooled down till it takes the form of
minute drops of water, electricity is abundantly produced.
This evolution of electricity is the more sudden, the
more rapid the condensation. Thus, when rain falls
calmly, and clouds resolve themselves slowly, the
electric phenomena are not very remarkable. But
when the downpour is sudden, and the clouds are
instantaneously transformed into a mass of water, the
electricity has not sufficient time to disperse gradually,
and there comes a clap of thunder. This explains why
lightning in thunderstorms usually accompanies a
sudden increase of rain. This sudden downpour is
due to the mixing of two masses of air of different
temperatures ; it is the effect of a sudden wind in
the cloud region. The result is a brisK condensation
torrents of water are precipitated to the ground, and
with them, torrents of electricity. Eain and lightning-
issue at the same time from the cloud, and if we usually
observe that the downpour follows the lightning, it is
126 THE EARTH'S ATMOSPHERE.
because a certain interval is required for the rain to
reach the Earth, whilst the light of the electric flash
reaches it instantaneously.
We can therefore admit this law, which is precisely
in contradiction to common opinion, that the, electric
phenomena of the atmosphere are the consequence and not
the cause of thunderstorms.
Ordinary rains do not differ from thunderstorm rains,
except in degrees of intensity ; both give birth to
electricity in the one case, almost imperceptible; in
the other, terrible by its intensity.
The formation of snow from the vapour contained in
the atmosphere, like that of hoar frost, is an example of
crystallisation precisely similar to what occurs in the
sublimation of benzoic acid, iodide of cyanogen, etc. ; the
nucleus of a crystal is formed by the fall of temperature,
and the crystal rapidly increased, by contact of the vapour.
Snow is not exactly frozen water : when rain freezes, as
I have sometimes witnessed, it forms pear-shaped solid
drops. Crystals of snow and hoar frost are formed
differently; they are the result of a true crystallisa-
tion, giving rise to exceedingly beautiful forms of the
hexagonal type ; whilst frozen rain, and ice generally,
are the result of a sudden coagulation, a solidification in
which crystalline structure is much mixed up, confused,
and indistinct.
With a slight frost snow is abundant ; it then falls in
large flakes; but during long frosts snow is rare, the
flakes are smaller. They end in forming tiny grains, a
kind of dust of snow, such as was experienced during the
CLOUDS. 127
recent prolonged winter 1894-95. It is very rare,
indeed, to have any fall of snow when the thermometer
sinks to many degrees below freezing-point, to 15 C.
(5 Fahr.), for instance. At this very low temperature
the quantity of vapour which the atmosphere can contain
is not sufficient to form clouds of any size. 1
The formation of hail is still an unsolved problem ; it
varies in size from the weight of a few grains to as
much as nearly half-a-pound ; the latter being, however,
quite exceptional. It precedes, or accompanies storm
rain, never follows it. It rarely lasts more than a few
minutes ; very rarely as long as a quarter of an hour.
It is much rarer at night than in the daytime. I
explain the fact of its dancing on the ground by its
highly electrical state. It is quite possible to conceive
that it may sometimes enclose solid particles which
happen to be in suspension in the atmosphere, as in
the singular observation of Baumhauer referred to in a
preceding chapter.
Houzeau explains the phenomenon of hail by saying
that if the drops of rain are formed in the higher warm
current of air, or in some cloud heated by the sun's
rays, and if they meet on their descent with a cold
1 During a recent severe winter a number of persons were dining
together in St. Petersburg. The room was very warm and contained
much moisture from the steaming dishes and the breath of the persons
present. One of the guests accidentally broke a window, which
caused a stream of intensely cold air to flow into the apartment. Jn
an instant, flakes of snow began to fall, and soon covered everybody
in the room, just as if the guests had all been in a fall of snow out of
doors. A similar occurrence has been previously observed, on several
occasions, in the Arctic regions, at Nova Zembla, and in Siberia.
'128 THE EARTH'S ATMOSPHERE.
current, they arrive at the ground in a frozen condition
as hail. This, he continues, is why hail "is most
frequent in Spring " ; the conditions for its formation
being best fulfilled at that season. But the most severe
hail is that which falls in Summer, during thunder-
storms, and proves so disastrous to the crops in Central
and Southern France.
Why it is more frequent in the daytime than at night,
the same eminent writer says, is a question that applies
also to thunderstorms : it is because sudden currents of
air (which are termed in French, "grains" "coups de
vent") are more common in the daytime. "They are
due .to the inequalities of temperature produced by the
sun's rays on certain portions of the air, whilst other
portions are in the shade."
If we admit Faye's theory (Comptes-rendus, 1895),
the phenomenon of hail may be explained by assuming
that it is due to the minute crystals of ice sucked down
from the higher regions of the air into the vortex of the
storm-cloud.
A few years ago I was witness in England of a most
-remarkable phenomenon, which I may call a cloud-arch,
and the only observation of a similar kind that I have
ever met with is contained in a few words inserted in
the Memoirs of the poet Goethe, who witnessed it
during his visit to Girgenti in Sicily. I will endeavour
to describe, first, exactly what I saw.
We were travelling, my wife and I, from London to
Bournemouth in August by a train which left London
shortly after noon. We had not gone many miles into
CLOUDS. 129
the country before I noticed, in the far distance, a
singular arch of light cloud, which lay about 20 above
the horizon, exactly in the direction we were proceeding,
that is, nearly due south-west of us. As we progressed
on the journey the arch rose higher and higher above
the horizon, so that in about two hours its summit
approached the zenith of the spot where we then were,
and beneath it was a pale, lavender-blue sky, quite
devoid of cloud.
After awhile, when our train reached Eingwood
junction, only a short distance from Bournemouth, we
passed right under the arch of cloud, the summit being
then at a great elevation in the atmosphere ; and as we
did so, we were sensible of having passed into quite a
different climate ; we had come, if I may so express it,
from a season of Spring^ into one of Summer. One of
the feet of the arch appeared to rest on the land some-
where beyond Eingwood, and the other over the sea, on
the Isle of Wight. This singular " cloud-arch " remained
perfectly still, apparently, during the whole evening.
Next day, I saw nothing of it.
This is what Goethe says of a similar observation in
Sicily :
" Girgenti, 27th April. Standing by the side of the
sea, my attention was attracted by a long streak of cloud
over the southern horizon, like an immense chain of
mountains. These clouds indicated the African shores.
Another phenomenon appeared to me still more singular ;
it was light cloud forming a vast half circle, leaning on one
side on the soil of Sicily, rising boldly into a clear blue
j 30 THE EARTH 'S A TMOSPHERE.
sky, and bending down towards the position of the
Island of Malta ; and this half circle, I was told, often
appeared in the air. Could it be a mysterious mani-
festation of the attractive force existing between these
two islands ? "
This quotation proves that the phenomenon was an
unusual one to Goethe (who was a man accustomed to
observe the phenomena of Nature), and, therefore, by no
means common in our northern climates, though he was
told it was often seen in Sicily. I find no description
of this singular phenomenon in any work on Meteor-
ology ; but I have related in my little work on Phos-
phorescence (London, 1862) an account of an auroral arch
witnessed by the late General Sabine in the Greenland
seas, who kindly gave me a description of it, at the time
he was President of the Royal Society. His vessel, the
Isabella, sailing south, passed into one of the legs of the
arch, at night, during which time everything on board
the ship became visible by a diffused yellowish light,
which was left behind as they proceeded on their
voyage ; the luminous arch then appearing in the
distance, as it had done before they approached and
entered one of the sides of it.
The two phenomena just related are difficult to
explain in a few words ; but, according to my ex-
perience, there is a marked difference of climate (if I
may so express it) on each side of the arch.
CHAPTER XIX.
Influence of the Gulf Stream on the State of the Atmosphere over
Europe and the Atlantic The Curve of Average Tempera-
ture and its Teachings.
THE influence of the Gulf Stream upon the state of
the atmosphere over Europe and the Atlantic Ocean
has been vividly brought to light, more especially by the
indefatigable labours of Maury. This immense current
of warm water is referred, to several causes, the principal
of which is the tendency of the warm tropical waters to
flow towards the poles, their high temperature making
them lighter than the waters of the colder regions.
The direction of the current is due, partly, to the rota-
tion of the globe, which naturally deflects towards the
east both the winds and the ocean currents.
Leaving the Gulf of Mexico, whence it derives
its name, and passing the Straits of Florida, the
Gulf Stream flows through the canal of the Bahamas,
and pours itself into the Atlantic Orfean, where its
waters preserve, for thousands of miles, their high tem-
perature, and their direction towards the north. In the
Gulf of Mexico this temperature is about 75 Fahr. ;
and when it merges into the Atlantic about 72 Fahr.
132 THE EARTH '5 A TMOSPHERE.
some twelve degrees higher than that of the Ocean in
the same latitude. When it has flowed over ten degrees
of latitude, still further north, it has only lost about
4 of heat ; and after a course of 3000 miles, in a
northerly direction, it still preserves, even in the depth
of winter, the mild temperature of summer.
Thus it arrives at the 40th parallel of north latitude,
and then, spreading out, it covers many thousands of
square miles, bestowing upon this vast surface its con-
genial warmth. Meeting with the banks of Newfound-
land, where it gives rise to dense fogs which are so
dangerous to navigation in winter, it deviates towards
the east, and continues its course with less impetuosity,
until it reaches the British Isles. There it divides into
two branches, one continuing towards the north to the
polar basin of Spitzbergen, whilst the other, flowing
down the English coasts, throws itself into the Gulf of
Gascony, both branches preserving a temperature several
degrees higher than the ocean. 1 Its influence on the
Orkney Islands is such that although situated at 60
north latitude, ponds rarely freeze in winter, and the
climate of Liverpool, for instance, which is more
northerly than Newfoundland, is quite rnild and
agreeable; whilst Labrador, which corresponds to
England on the American coast, is almost uninhabit-
able. If the temperature and velocity of the Gulf
Stream were the same at 200 fathoms as at the surface,
the quantity of heat evolved from its waters into the
1 Ships that are covered with snow and icicles experience the effects
of a rapid thaw the moment they enter the waters of the Gulf Stream.
f TEMPERA TURE. 1 33
Atlantic would, according to Maury, suffice to raise
from freezing-point to summer temperature the entire
bulk of the atmosphere lying over Great Britain and
France.
Most of the atmospheric perturbations of the At-
lantic Ocean can be traced to the influence of the Gulf
Stream. Not only the fogs of Newfoundland, but the
disastrous tempests of wind, or hurricanes, which
occasionally blow in certain parts of the Atlantic,
appear to be due to the difference of temperature
between the waters of this vast current and those
which surround it. Storms have been traced from the
west coast of Africa and followed across the ocean until
they meet with the waters of the Gulf Stream, when,
instead of continuing their straight course, they
suddenly change their direction, and blow again across
the Atlantic, till they reach the coasts of Europe,
marking their trajectory by a series of calamities.
The mild climate of the British Isles is very greatly
due to this immense current of warm water, without
which we should be no better off, in this respect, than
people who live in the Arctic circle.
There can be little doubt that, as there exist in the
Earth's atmosphere, fluctuations of temperature, of
electricity, of barometric pressure, and of magnetic
force, this vast stream of warm water may, also, have
its periodical fluctuations of quantity, or temperature,
and I am of opinion that it may thus affect what is
known as the curve of average temperature.
After a careful consideration of this curve of average
134 THE EARTH'S ATMOSPHERE.
temperature in our climate, for every day of the year
for forty years, I find that, in any given month of the
year, this line tends to rise in a very marked manner
from the 10th to the 25th of each month. The only
remarkable exception to this law is during the few
cold days about the 12th May, which, as I have
previously hinted, are probably due to the absorption
of atmospheric heat by the melting of the winter
snows and icebergs, and to the position of the belt of
November meteors, which, at that period, is between
us and the sun.
CHAPTER XX.
Aerolites, or Stones from the Air "Thunderbolts" A Stroke of
Lightning A Fall of Meteoric Stones Belt of Meteorites
round the Earth Shooting-star Orbits and Comets
Old Opinion of the Indefinite Extension of the Earth's
Atmosphere.
THERE was a time, not so far distant from us, when
aerolites stones from the air were supposed to be
formed in the atmosphere of the Earth, from the
exhalations of the soil* becoming condensed in the higher
regions, and then falling heavily to the ground.
The phenomena which accompany these falls of
aerolites, of which one, at least, occurs every year upon
some part of the Earth's surface, are so similar to what
is observed when lightning strikes any object, that
they were once called " thunderbolts " ; and as aerolites
always contain more or less sulphur, the common rolled
pyrites (sulphide of iron), found on the sea-shore, also
got this appellation of " thunderbolts ," and these rounded
stones of common mundic, were often put away in
collections as "aerolites," or " meteorites" that is,
stones which have fallen from the sky.
When lightning . strikes an object on the Earth's
136 THE EARTH'S ATMOSPHERE.
surface (as it did on the 17th April 1895, at about
4 p.m., between Putney and Barnes, a few yards from
where I stood), the effect is like that of a large piece
of artillery. The light and sound are instantaneous ;
a ball of vivid red light, about the size of a child's head,
shoots from the sky to the earth with greater rapidity
than a ball from the mouth of a gun, and the single
report of the explosion is coincident with the flash.
In the case of a fall of aerolites, the noise occurs
like a rumbling of loud thunder, which is heard only
some considerable time after the fall of the stones.
There is also a peculiar metallic ring in the thunder
of the aerolite ; but I have heard that, also, when
lightning strikes, as it did in July 1894, a short distance
from where it fell on the 17th April 1895, as just
mentioned. It is like the shaking of huge chains. I
have heard it on some other occasions also ; so that
the metallic sound may occur in both cases.
The lightning stroke leaves nothing behind it save
a slight mist, an odour of sulphurous vapour, and its
peculiar effects on trees, animals, or houses, etc. In
many cases, houses have been struck by lightning, and
the inmates have experienced nothing but alarm from
the noise, little or no traces of any effects being after-
wards found. After a fall of aerolites the stones are
found either on the ground or buried a few feet below
the surface.
In my volume on Meteors, Aerolites, and Falling Stars,
published in 1867, I have given a complete history
of these phenomena, and their distinctive character-
AEROLITES SHOOTING-STARS. 137
istics. I have there given the chemical composition of
all the principal aerolites which have been picked up
shortly after they were seen to fall, and then submitted
to analysis; also, a classification of the three kinds
according to the amount of metallic iron they contain.
This amount may vary from less than 1 per cent., to
98 or 99 per cent., the rest consisting of silicates and
sulphides, but it is always present, and it always
contains some nickel (another magnetic metal, like
iron).
In the work just mentioned, I have also given a
theory of my own with regard to the origin of aerolites,
namely, that they form a ring of minute satellites
around the Earth, like the ring of Saturn which is
now, also, being found to consist of a vast number of
minute satellites, and so far confirms my theory of
1867.
At certain intervals, the position of the Earth in its
orbit is such with regard to other planetary bodies, that
some fragments from this dark ring are attracted to its
surface, and crash through the atmosphere as " fire-ball
meteors" which explode with violence, and shower down
stones, or metallic fragments of various sizes from that
of a walnut or less, to that of a man's head ; or, even,
far greater than this, if the immense masses of iron
found in Australia (now in the British Museum), and at
Ovifak, Greenland, are really aerolites.
These falls of stones from the atmosphere have been
observed for some hundreds of years before Christ,
down to the present time. Formerly, they were
J38 THE EARTH'S ATMOSPHERE.
thought to be shot from volcanoes in the Moon. They
are, no doubt, of the same chemical composition as the
Moon; and are, I believe, minute satellites of our
Earth, thrown off like our larger satellite was thrown
off, in the earliest ages of its existence.
That is, perhaps, a better theory than supposing them
to be shot out from our terrestrial volcanoes in activity
at the present time.
Shooting-stars are quite different. Formerly, they
were thought to be the same phenomenon as bolides, or
aerolites : and I myself classed them all in one category,
which a learned writer in the Saturday Review thought
rather premature and he was right. Since the dis-
covery made by the Italian astronomer, Schiaparelli
(made known since my work on Meteors was published),
that the swarms of shooting-stars which arrive in our
atmosphere at certain stated intervals, present the same
orbits as comets, these two classes of natural pheno-
mena (comets and shooting-stars) are believed to be one
and the same. Before Schiaparelli's time, Keichenbach
held a similar opinion.
This is what I wrote on aerolites in 1867 : " Taking
especially into consideration the chemical composition
of aerolites, we may be tempted to suppose that these
meteoroids have orbits round the Eartli, not round the
sun, and that they constitute a series of dark rings
around our globe, similar, perhaps, to the rings of
Saturn." (Meteors, etc., loc. cit.)
This quotation is interesting now that Professor
Keeler, and others, are endeavouring to prove that
AEROLITES SHOOTING-STARS. 139
Saturn s ring is composed of small asteroids (meteoroids,
aerolites).
There was also a time, not yet more than a century or
so removed from us, when many philosophers held that
the Earth's atmosphere extended indefinitely around the
globe, becoming more and more rarefied the density
decreasing in geometrical ratio, whilst the distance from
the surface increased in arithmetical ratio, according to
the celebrated Halley until it blended with the rarefied
atmospheres of other planets. But when it was found
that no atmosphere of any kind could be detected
around the Moon, this theory began to give way ; and
it was supposed, henceforward, that the Earth's atmos-
phere, whether it extended to 50 or to 500 miles,
was limited; that it participated in the diurnal and
annual movements of the globe, and was held to the
Earth by gravitation, just as a pebble on a garden walk.
But just as the pebble may, under the influence of the
spade or rake of the gardener, have its own independent
motions, so our atmosphere, under that of the Sun's
rays, is in a constant state of change and activity.
CHAPTEK XXL
The Organic Matter of the Atmosphere Effluvia, Miasma,
Malaria, etc.
THE organic matter contained in the Earth's atmosphere
has been touched upon in several previous sections of
this little work, but a few more observations are
requisite to complete our notions upon this important
subject.
When a current of atmospheric air is passed, for a
certain length of time, into pure sulphuric acid, this
liquid, which is originally as white and transparent as
water, becomes more and more coloured, and finally
dark brown. The quantity of air thus passed, before
the brown colour is obtained, supplies some indication
of the 'absolute amount of organic matter present in the
atmosphere of a given locality at the time the experi-
ment is made.
This organic matter has been found to consist chiefly
of microscopic cells, quite invisible, and not affecting to
any great extent the transparency of the air. These
cells are brought down in large quantities by snow and
rain ; they can be filtered from the air by passing it
through cotton wool, as two German chemists, Schroeder
MICROBES. 141
and Dusch, showed many years ago ; and they are com-
pletely destroyed by fire, which is the most effective of all
disinfectants.
These microscopic cells are constantly present in the
atmosphere in all parts of the globe, to a greater or less
extent, according to circumstances ; they are organized
beings which play an important part in the economy of
Nature. Before they had been scrutinized by the
scientific methods of modern times, their existence had
long been suspected; and they have been successively
alluded to as effluvia, malaria, miasma, bacteria, microbes,
germs of disease, ferments, etc. They are extremely
numerous, and varied, infinitesimally minute, and are
the promoters of fermentation, decay, and diseases of all
kinds, both in animals and plants; at the same time,
they contribute to the fertility of the soil, and the
purification of air and water, thereby promoting health
and vitality.
One of the greatest achievements of the science of
the nineteenth century is to have brought to light the
nature of what the old naturalists and physicians used
to speak of vaguely as miasma and virus. The successive
experiments and observations of Schwann of Berlin in
1837 (who calcined his air), followed by those of
Schultze, who passed the atmospheric air through
sulphuric acid, and found it incapable of producing life
in organic liquids which had been boiled, whilst air not
so treated allowed the production of algce and infusoria
of all kinds; of Schroeder and Dusch (in 1854 and
1859), who filtered air through cotton wool, and found
142 THE EARTH'S ATMOSPHERE.
it, also, incapable of promoting the decomposition of
sterilized beef -broth, the cotton wool having retained
the germs ; and finally, the observations of Dr. Davaine
(1856), and M. Pasteur (1859), have brought this branch
of knowledge to a great degree of perfection. At the
present time hundreds of investigators are following up
the researches of these clever observers in all parts of
the civilized world.
When water is boiled for some time, these microscopic
organisms which, like the air, it always contains, are
destroyed. The water is then "sterilized," as it is
termed, and no life can be detected in it. But by
exposing it for a certain time to the atmosphere, and to
sunlight, green matter is seen to form in it : microscopic
plants, the germs of which have fallen from the air,
develop in it rapidly, and are soon buoyed up to the
surface of the liquid by the bubbles of oxygen gas which
they secrete.
The ease with which the germs of these extremely
minute organisms are dispersed through the atmosphere
became very apparent in one of my recent experiments ;
a few bubbles of carbonic acid gas having been passed
into a long tube nearly full of nitrogen, through water
in which this green matter had developed, I noticed in
a few weeks some excessively minute specks at the very
top of the tube, a foot and a half from the surface of
the water. In time, these tiny specks turned green
and increased in size; they were found to be algce,
identical with those in the water below. Their germs
had been carried up through the nitrogen gas, and had
MICROBES. 143
developed on the moist sides of the tube, near its upper
extremity.
All these minute mono-cellular organisms, which are
quite invisible in the air, have always played a most
important part in Nature, from the earliest geological
ages of our globe to the present time. They were, as I
have shown, the first producers of free oxygen gas in the
atmosphere of the Earth, by which, alone, animal life
became possible. They are the cause of biological
phenomena of all kinds, by which the Earth retains its
fertility. They multiply with the most astonishing
rapidity, which compensates for their minute size and
short cycle of existence. They are the first principles
of life, and of vital activity in health and disease.
These microbes, as they are now often called, have
been classed into two categories those which appear to
be harmless, and those which give rise to disease in
plants and animals. But this classification is very
arbitrary. Certain kinds appear to be present in
greater numbers in times of epidemics ; and it is
generally supposed that epidemics of measles, scarlatina,
diphtheria, small-pox, cholera, influenza, typhoid fever,
etc., are due to the prevalence, at certain times, and in
certain localities, of the special microbes of these various
maladies. However that may be, it is quite clear that
the whole population of a district is not' attacked at once,
and that, in the most virulent of epidemics, a great
number, we may say by far the greatest number of people,
are never affected at all, though they must all have been
penetrated with the microbes in the same manner as
144 THE EARTH'S ATMOSPHERE.
those who were affected. This shows that it is only in
the blood and tissues of persons who are more or less
delicate that the microbes of the atmosphere find a soil
suited to their development, and that on persons in
tolerably perfect health they have no effect at all.
For more ample details on this important subject, I
must refer to my History of Bacteria, which appeared
in the early numbers of my medical journal. 1 The
cause of disease must be looked for beyond bacteria.
1 Phipson, " A History of Bacteria," and " Supplements to a History
of Bacteria," in Journ. of Mecl., etc., London, 1880-1894. See also my
Health Notes and Curiosities of Medical Science, London, Routledge,
1898, one vol.
CHAPTER XXII.
State of the Atmosphere in any given Locality Immediate
Weather Table for British Isles and Northern Europe
generally Rainfall.
FROM a practical point of view, the instruments which
are the most useful in supplying data regarding the
state of the atmosphere in any given locality are the
barometer and thermometer.
Before the present system of telegraphing the weather
to be expected in any particular quarter was put into
practice, it was quite possible, by a careful observation
of these two instruments, to foretell by about twenty-
four hours what kind of weather was coming. But such
observations were rarely made; few seaports were
properly provided with these instruments, and their
indications were nowhere precisely understood.
I have already mentioned several important indica-
tions supplied by the barometer and thermometer ; and
I will now add a few practical detaite as regards the
immediate weather of any given locality that is, the
weather that may be expected in the next twenty-four
hours as it can be foreseen by scrutinizing the move-
ments of the mercury in the barometer, the direction of
K
146 THE EARTH'S ATMOSPHERE.
the wind at the time of observation, and the aspect
presented by the sky.
Fitz-Koy has laid down the rules for the barometer in
a very clear manner. 1 It rises in our north latitudes for
cold, northerly (K, N.E., N".W.) winds, less wind, and
dry air ; and it falls for warm, southerly (S., S.E., S.W.)
winds, for more wind, and wet, the only exception
apparently being, occasionally, with wet from the north-
east (when it remains high). In the Southern hemi-
sphere the words "south, southerly," etc. must be
substituted for " north, northerly," etc.
The barometer expresses the connection of the present
wind with that ivhich is about to Mow ; and this alone is
sufficient to render its indications of very great service
to us.
Such being the case, I will give here a little table, the
indications of which are the results of long experience,
feeling certain that it will prove extremely useful.
The first thing to be done is to ascertain the direction
of the wind by observation of the weathercock, or, better
still, by the direction of the lower clouds. Then, we
must observe with care the state of the barometer and
the thermometer. It will be best to make these
observations always at the same hour, say between nine
and ten in the morning, regularly.
Here is the little table in question : it applies to the
British Isles, Belgium, Germany, France, and northern
Europe generally.
1 Fitz-Roy, The Weather Book, second edition, p. 10.
WEATHER.
147
IMMEDIATE WEATHER.
Direction
of wind.
State of the
barometer.
State of the sky.
Weather to be expected.
Rising.
Clear sky.
Cloudy sky.
Cold and dry weather.
The sky clears.
Rain or snow.
Wind passes to N.E. ;
Nj
showers and sunshine.
<
After a gale.
Air cools and remains
fine, then gets warmer
by the sunshine.
Falling.
Clouds rise, weather gets
warmer for a time.
Rising. .
Cold rain, or snow.
Clear sky.
The wind continues ; dry
weather established.
Cloudy sky, with
Wind continues ; fine
Steady. (
rain or snow at
weather returns.
the commence-
ment of the
N.E. wind.
Fine ; small
Heat, without rain.
mottled clouds,
very high.
N.E. ,
Fine ; slight haze
Rain in summer, thaw
Falling.
over the sky,
stars pale.
in winter.
Showers at in-
Wind passes to E. or S. ;
tervals.
the sky gets covered
with small round clouds,
or becomes quite fine.
Continuous and
Fall of freezing rain :
rigorous cold,
" silver thaw," soon
apparition of
followed by milder
white haze over
weather.
the sky.
+
\
Overcast.
Wind goes S.E. or) S. ;
sky clears ; cold is in-
tense, then cloudy and
thaw within 24 hours.
148 THE EARTH'S ATMOSPHERE.
IMMEDIATE WEATHER continued.
Direction
of wind.
State of the
barometer.
State of the sky.
Weather to be expected.
Rising.
Cold rain, or snow, ac-
cording to the season.
(
Fine
Wind persists ; dry
Steady.
Cloudy, after
weather lasts.
The wind persists ; sky
(
rain or snow.
gets fine.
Fine, little light
Heat, without rain.
/
clouds.
Overcast or
Rain.
E. \
Falling.
cloudy.
Heat continuing
More rain.
after rain.
V
Snow.
Turns to rain ; milder
weather.
t
Fine.
Tempest of wind from
Falling
rapidly. J
the S. ; sometimes ac-
companied by thunder-
storm.
^
(
Overcast.
Wind passes suddenly to
S. ; sky clears ; air gets
dryer for several days.
S.E. 1
Rising.
Cloudy sky, passing
showers.
1
Falling.
Clouds increase ; wet
weather generally
comes on soon.
/
Rising.
Fine weather ; rarely
durable.
i
Fine.
Clouds form ; weather
S. <
Falling.
Cloudy.
changes.
Clouds increase ; rain.
(
After a gale.
Close, rainy weather.
Falling
Storm of wind, especially
rapidly.
in winter, and generally
when the thermometer
is very high for the
season.
WEATHER.
IMMEDIATE WEATHER continued.
149
Direction
of wind.
State of the
barometer.
State of the sky.
Weather to be expected.
Rising very
quickly.
Wind soon goes to N.E.
Prolonged cold ; especi-
ally in spring.
Variable and un-
Rain almost certain.
certain weather.
Fine rain, low
Wind goes W. ; clouds
Rising.
clouds.
increase, heavy rain ;
air colder.
Violent wind
As soon as the barometer
\
(gale).
begins to rise, the wind
passes in a few hours to
S.W. <
N. W. , still strong and
then N.E. with cold.
Rising slowly
after being
...
Wind goes to N.W. and
remains there. We
very low.
may expect westerly
winds for the rest of
the season.
Falling.
Warm weather
Wind soon goes round
after westerly
with rain.
rains.
Falling very
...
Persistent rain.
low and for a
>
long time.
/
Rising
N. winds of short dura-
rapidly.
tion. Wind goes again
S.W. and the baro-
meter falls again ;
generally not so low as
W. ,
before.
f
With falling ther-
Rain almost certain.
mometer.
Without an im-
E. or N.E. wind; sky
mediate fall of
charged with cloud ;
,
Rising. \
the thermo-
raii>, snow, or fog. But
meter.
the weather gets fine,
and cold if E. wind
continues.
Rain.
The thermometer falls ;
wind goes N.W. ; rain
persists, and in winter
becomes snow.
i$o THE EARTH'S ATMOSPHERE.
IMMEDIATE WEATHER continued.
Direction
of wind.
State of the
barometer.
State of the sky.
Weather to be expected.
Rising.
Snow.
Cold. If the N.W. wind
brings more snow the
cold increases and
becomes severe.
Rising slowly.
Oscillating.
Constancy of N. winds.
Scuddy, changeable
m
weather.
W.
Falling.
Weather gets warmer ;
rarely rain is immedi-
ate, but falls as the
rotation of the wind
is re-established.
Falling very
Abundant rain.
Gale from the S.W.
low.
,
Uncertain, or
Clear sky, cold.
fine weather.
Rain or snow.
Wind goes N. or N.E. ;
showers and sunshine ;
blue sky between the
Rising. 4
Snow, after other
showers.
Cold ; which will be
snow from W.
severe.
N.W.!
Wind very strong
Cold ; wind goes N.E.
after a gale,
thermometer
Falling.
falling briskly.
Milder interval without
rain, until the baro-
meter rises and the
wind goes round ; at
this moment rain falls.
This table, which was drawn up by Houzeau, first
assistant to the celebrated Qnetelet, director of the
Brussels Observatory, has been tested by me on many
occasions in Belgium, France, and Great Britain ; it has
proved generally correct for the first two countries, and
WEATHER. 151
tolerably so for England, where the weather is more
changeable, and at the same time more temperate,
than in other parts of Europe. Nevertheless, it is only
an indication of probable results; it contains nothing
absolutely certain.
It is now almost a century since our great English
meteorologist, Howard, turned his attention to the
amount of rain which falls in a given locality and at
a given season. Speaking of England, some have said
that April is the driest month, and October the wettest ;
but Fitz-Koy says March and July.
Howard showed, long ago, that the quantity of rain
which falls in London in one year is very variable :
In 1802 he found 14 inches; in 1810, 27|; and in
1816, 32 inches.
Symons puts the mean rainfall per annum for London
at %5 inches, and for all England at 31 inches. The
proportion for the various seasons is roughly stated as :
Winter 5*8; Spring 4'8 ; Summer 67; Autumn 7*4;
total = 24*8 inches. But averages (or means) are only
useful for comparison. Engineers require to know the
extremes', for these are what are actually experienced,
and what we have to deal with in practice. For in-
stance, more rain may fall in an hour than is due
to one month, according to averages. If the flow of
water in our rivers during a dry season is taken as
unity (one volume), the volume in wet weather is
generally 300, and in extreme cases 500. A river in
England may rise, from floods caused by rain, as much
as 23 vertical feet; and in South Africa, and America,
152 THE EARTH'S ATMOSPHERE.
etc., as much as 60 or 70 feet. As regards waterworks,
we must know the minimum ; for bridges, culverts, and
embankments, the maximum of water which the atmos-
phere will yield in a given locality.
It is not generally known that the rainfall of all
towns in Great Britain is more than sufficient, if it
were collected, to supply all the wants of their inhabi-
tants as far as water is concerned.
CHAPTEK XXIII.
Fogs and Electricity Konayne's Discovery Luminous Fogs
Prevention of Thunderstorms and Hail.
THOUSANDS of tons of water are evaporated daily from
the waters of the ocean by the heat of the sun's rays ;
this water rises as vapour into the air, forms clouds,
fogs, and dew; falls again as rain, produces springs,
streams, and rivers, which flow to the sea, and whilst
protecting the surface of the Earth from the effects
of undue radiation, gives to the soil that degree of
moisture which is essential to life and fertility.
Fogs, in the days of Sir Humphry Davy, were
thought to be always due to the cooling of the air lying
over water ; and, no doubt, a mist is often formed from
this cause ; but that is not invariably the case. George
Harvey, in 1823, contradicted Davy's statement, and
showed that fogs were sometimes formed when the
temperature of the air on the land is higher than that
of the water and the air above it, ir> which the fog
exists. As early as 1814 five years before Davy's
observation Thomas Young showed, on the occasion
of a remarkable fog which lasted from 27th December
1813 to 23rd January 1814, in London, the tempera-
154 THE EARTHS ATMOSPHERE.
ture varying during this period from 21 to 34 Fahr.,
that difference of temperature between the air and the
water could not explain such a phenomenon.
The fact is, that electricity plays a great part in the
production and duration of fogs. An English observer,
Thomas Eonayne, first discovered (in 1761) that fogs
are highly electrical, quite as much so as clouds. His
observations were published in the Philosophical Trans-
actions, but attracted no attention till they were re-
peated in 1774 by Henley. In more recent times,
much attention has been given to the subject by
Peltier, a Belgian observer. 1
The Earth being always electro-negative, the fogs
are sometimes electro-positive, and sometimes electro-
negative. In the latter case, being repelled by the
soil, they do not wet the Earths surface. But there
exists a rare kind of electro-positive fog which does not
wet the ground either. Such was, for instance, the
celebrated dry fog of 1783, which made its appearance
at about the same time in many distant places, spread-
ing from North Africa to Sweden. It exhaled a
disagreeable odour, was remarkably dry (not affecting
the hygrometer at all), and was decidedly luminous at
night ; sufficiently so to enable a person to see objects
at a distance of 600 feet ; and it lasted about a month.
Fogs are often so electrical that they diffuse much
light at night. 2 A remarkable instance of this was
1 Peltier, Memoire sur les diverses espece de JBrouillard, Bruxelles,
1842.
2 Phipson, Phosphorescence, etc., London, 1862 ; and Familiar
ELECTRICITY. 155
noticed by Professor Wartmann, of Geneva (18th to
26th November 1859). The moon, being new, was
invisible, but a vast fog, not damp enough to wet the
Earth, but so opaque as to render invisible the borders
of the river Leman and the Mont Saleze, lay over
Geneva and its environs. It diffused so much light,
that a person walking from Annemassa, in Savoy, on
the 22nd November, saw his way as clearly as if it
had been a moonlight night. Auguste de la Rive, the
well-known electrician, made a similar observation
about the same time.
In 1863, Dr. Meissner, of Gottingen, 1 showed that
moist air submitted to the action of electricity in closed
tubes produced a mist, which did not disperse on being
passed through water, but appeared again on the surface
of the water, and lasted about half an hour, after which
it gradually disappeared, depositing dew on the sides of
the glass vessel.
It is probable that if a few high towers, surmounted
by very long metallic rods communicating properly
with the Earth, were erected around our large cities,
the latter would be rarely or ever troubled by
thunderstorms. Such an arrangement would likewise
prove very beneficial in the wine districts of France, in
such places, for instance, as the little town of Tonnerre
(ominous name !), where thunderstorm^, with hail, cause
so much destruction to crops and property. It has been
Letters, London, 1876. Peltier, Memoirs of the Acad. of Sc., Brux-
elles, 1842.
1 Meissner, Untersuch. iiber den Sauerstojf, Hanover, 1863.
156 THE EARTH'S ATMOSPHERE.
recorded that the late Professor Charles, a well-known
French scientist and aeronaut, more than once succeeded
in arresting the progress of a thunderstorm, which was
approaching Paris, by sending up an immense kite with
a metallic string. When I resided in Paris, before the
Franco-German war, the wooden stand to which this
kite was attached was still preserved at the Conservatoire
des Arts et Metiers \ the wood appeared to have been
thoroughly calcined by the numerous electric discharges
that had fallen upon it from the atmosphere. Dr.
Lining, of Charlestown, U.S., and De Romas, of Nerac,
in France, seem to have entertained no doubt on this
subject ; and once Frangois Arago said that he believed
the problem of transforming thunder-clouds into ordinary
clouds had been solved. Ib is admitted that, by sub-
tracting their electricity, thunder-clouds can be pre-
vented from forming hail; and if this be really the
case, it would be most important to establish in certain
districts a catching agency of captive balloons, kites, or
towers with metallic rods, communicating with a water-
course, or with the moist soil ; for not a year passes
but hail does great damage at such places as Rieux,
Comminge, Lombez, Tonnerre, etc. Some time ago I
saw an official report that showed damage to crops
amounting to one million pounds English money, after a
single thunderstorm in France.
The kite which M. De Romas flew at Nerac, the
string of which was surrounded by fine copper wire,
effectually subtracted electricity from the storm-clouds ;
and whilst these experiments lasted, no lightning was
ELECTRICITY. 157
seen, nor thunder heard. Yet this kite only rose about
160 yards into the atmosphere ; and in presence of com-
paratively small thunder-clouds, he drew from the string
flashes of lightning from 7 to 10 feet in length. In less
than an hour he got as many as thirty of such flashes.
CHAPTER XXIV.
Atmospheric Tides Magnetic Storms Sabine's Observations-
Absorption of the Moon's Atmosphere.
THE attraction of the Sun and Moon upon the waters
of the Earth, giving rise to the phenomenon of tides, it is
evident that atmospheric tides must be produced in the
same manner, and affect the weather to some extent.
But no exact laws in this respect have yet been
established, and it is impossible to refer change of
weather, in any given locality, to the influence of the
Sun and Moon upon the atmosphere. Popular notions
on the effects of a " change of moon " upon the weather
are not borne out by scientific observations. 1
In reading the works of Maury, a modern scientific
observer cannot fail to be struck with the immense
amount of work which still requires to be done with
regard to the origin or cause, and even as to the
directions of the various currents of the ocean and the
atmosphere. His writings bristle with hypotheses
1 See on this subject P. Garrigou-Lagrauge, "Relations entre les
mouvements barometriques et les mouvements en declinaison du
Soleil et de la Lune '' (in the Comptes-rendus of the Paris Academy of
Sciences, llth February 1895, p, 342). See also a note by another
author in the Comptes-rendus for the 10th February 1896.
TIDES MA GNETISM ABSORPTION. 1 59
which observation has not yet confirmed, though he
has given us a considerable amount of useful experience.
Nevertheless, his notion of the cloud-ring of the equatorial
regions, which he likens to the ring of Saturn, his belief
in a current of air that reaches us from South America,
carrying red dust, in which Ehrenberg found the same
kinds of infusoria in whatever part of the globe this red
dust was collected, the statement that the magnetic
condition of the Earth may produce a retardation in the
progress of winds, and many other haphazard statements,
where imagination plays a much larger part than direct
experiment or observation, must not be allowed to mis-
lead us in the calm investigation of Nature's mysteries.
Humboldt is one of the few observers who have never
allowed hypothesis to take too large a place in his
writings ; and, at the present day, the patient labours
of the scientific expeditions, like that of the Challenger,
or even the more modest work of the Prince of Monaco
and the late Georges Pouchet, will, in after years, enable
us to reap far finer practical results than can ever be
expected of mere theory.
We have yet said little of the magnetic condition of
the atmosphere, the most difficult, complicated, and least
known of all its phenomena.
The wonderful discovery made by Faraday of the
paramagnetic property of oxygen gas, ''showing that it
takes polarity by the action of a magnet, just as iron
does, can have little or nothing to do with the beautiful
phenomenon of the Aurora borealis and australis,
which must have existed long before free oxygen gas
160 THE EARTHS ATMOSPHERE.
existed in the Earth's atmosphere, that is to say, long
before the advent of plant life.
During the Aurora the magnetic needle is affected
very powerfully, just as an ordinary electric current
affects it. The so-called magnetic, storms, which occasion-
ally interfere with the working of the electric telegraphs
in all parts of the world, mostly come on without any
previous warning, as we observe to be the case with
earthquakes. It is not yet certain whether these
magnetic storms are connected solely with the gaseous
envelope of our planet, with the Earth's solid crust, or
with some region underneath this crust.
The observations of Sabine l have shown conclusively
that the periodic variations of the magnetic activity of
the Earth cannot be based on periodic changes of
temperature in those parts of the atmosphere which
are accessible to us. Nor do the epochs of these periods
coincide with the maxima and minima of the tempera-
ture of the atmosphere. Nevertheless, the influence
of the Sun's position upon the manifestation of the
magnetic force of the Earth was known at a very early
period. Kepler discovered the horary variation of the
magnetic needle, and believed that all the axes of the
planets were magnetically directed towards one portion
of the Universe; he thought that the Sun may be a
magnetic body, and, on that account, the force which
impels the planets may be centred in the Sun.
Horrebow in 1730, who did not confound gravitation
and magnetic attraction, thought that light was the
1 Phil. Trans., 1850.
TIDES MA ONE TISM ABSORPTION. 1 6 1
effect of a perpetual aurora produced in the Sun's
atmosphere.
In both hemispheres, the epoch at which the intensity
of the terrestrial magnetic force (whether in the atmos-
phere or elsewhere) is greatest, is identical with the
period at which the Earth is nearest to the Sun, and
consequently when its velocity of translation is greatest.
Whether magnetism increases as we rise in the
atmosphere is a disputed question of minor importance,
since the great currents of the air keep its temperature
and electric condition in a constant state of change,
though its chemical composition remains apparently
constant. When the electric current, to which the Earth's
magnetism may possibly be due, is caused to flow through
very rarefied air, it gives rise, as everyone knows, to
appearances similar to those of the Aurora.
Humboldt observes that " it would be inconceivable
if, amid the harmonious co-operation of all the forces of
Nature, the paramagnetic property of oxygen gas and its
modifications by an increase of temperature should not
participate in the production and manifestation of
magnetic phenomena." But all this is mere suggestion ;
and it is far more probable that magnetic phenomena
occurred, as I have already intimated, before any free
oxygen existed in the atmosphere. It is certainly a
singular fact that oxygen, hitherto, is the only gas which
has been found to be paramagnetic.
The atmosphere is not only an essential medium for
the life of man, but for the life of the entire globe. No
manifestation of life on the Earth would be apparent
1 62 THE EARTH'S ATMOSPHERE.
if there were no atmosphere ; and should it be finally
proved that our satellite, the Moon, is quite devoid of
an atmosphere, it must be considered as a dead globe,
like the meteorites, which in all probability circulate
also round the Earth. But, strange to say, traces of
organic matter, which may or may not have been
derived from organized beings, have been discovered
in meteorites.
Some believe that the Moon once had an atmosphere
like that of the Earth, but that it has been absorbed.
What would happen if the Earth's atmosphere were
to be absorbed is too dreadful to contemplate. The
whole life of the globe depends upon it ; and we could
conceive nothing more desolate, cold, soundless, dark y
and dead than the Earth deprived of its essential
envelope.
APPENDIX A.
I. Account of an Experiment made with Convolvulus arvensis
vegetating in an Atmosphere devoid of Oxygen.
IN addition to the experimental notes I have already
published to demonstrate the truth of my new theory as
to the origin of atmospheric oxygen, I give here the details
of an experiment made with Convolvulus arvensis, a plant
which I have often used for this purpose, vegetating in an
atmosphere quite devoid of free oxygen, whilst two other
plants of the same species were growing alongside of the
apparatus as "witnesses," in ordinary atmospheric air.
This is one of the experiments which first showed me
that the plants of our present epoch are truly anaerobic,
like those of former geological periods, and that free oxygen
in the air is not essential for their existence.
This experiment with Convolvulus arvensis, vegetating in
what may be termed a "primitive atmosphere," is typical
of what occurs with all the phanerogamic plants previously
mentioned, and with the green unicellular algae such as
Protococcus palustris and the minute Microcystis or Chalmi-
domonas, etc., which develop in spring water exposed for
some weeks to the light.
The nitrogen was obtained from pure sulphate of ammonia,
1 64 APPENDIX A.
or by the action of potash and pyrogallol on atmospheric
air. It will be seen by what follows that the same volume
of nitrogen may be used over and over again, as it under-
goes no alteration in volume or properties, except such as
are due to oscillations of temperature and pressure.
The apparatus consists of a graduated tube, wide enough
to admit the plant easily, standing over water containing
minute quantities of all the substances known (or supposed)
to be necessary to vegetation, and kept supplied with carbonic
acid.
Alongside the graduated tube stands a smaller tube full
of water. Into this smaller tube carbonic acid is introduced,
at first once a day ; it displaces the water ; but in the course
of twenty-four hours the water has absorbed this gas, and
the tube is again full of water.
Carbonic acid is again passed into it next day, and the
water displaced, now saturated with carbonic acid, thus
finds its way to the roots of the plant. In this manner
the water of the basin in which stand the two tubes is
kept supplied with an appropriate quantity of carbonic
acid.
The whole apparatus is exposed to a constant northern
light, such as is used by artists, which I have found
preferable to a southern aspect, or to the direct rays of
the sun.
The temperature of the laboratory whilst this experiment
was carried out varied from about 60 to 90 Fahr.
One-half of the water in the little basin is covered with
a piece of plank, to procure darkness for the roots, and
a certain amount of carbonic acid is let into the wide
graduated tube from time to time.
APPENDIX A. 165
In this " primitive atmosphere " of nitrogen, containing
some carbonic acid, and vapour of water, vegetation is found
to be tolerably prosperous, in spite of the confined condition
of the air: the carbonic acid is absorbed and replaced by
free oxygen, so that after a certain lapse of time the gas in
the graduated tube approaches the composition of ordinary
atmospheric air, and can even be made richer in oxygen than
the latter.
First 75 cubic centimetres of pure nitrogen (reduced to
C. and 30 inches barometer) are introduced, and the little
plant being put in, makes the whole 102 centimetres.
Then a small amount of carbonic acid is let in, and the
volume of gas oscillates during the experiment from 102
to 130 c.c., according to the temperature and barometric
pressure at the time of observation.
The little plant of Convolvulus arvensis was introduced
on the 25th July 1893, its height being then 30 divisions
of the graduated tube.
On the 26th July it had grown to 37 divisions.
8*th 44
29th 48
30th ,, 51 when it began
to curve.
On the 31st July it had formed a new leaf and was
curving ; it now occupied 52 divisions of the tube.
On the 1st August it had curved considerably, as all
plants of the genus Convolvulus do, and measured only 50
divisions in height ; but on the 2nd August it had shot up
again to 64 divisions.
It appeared very healthy.
On the 3rd August it attained to 68 divisions.
166 APPENDIX A.
On the 5tli August there were new leaves formed, and
the plant measured now 70 divisions in height.
During the 6th, 7th, 8th and 9th of August, the plant
was healthy and two more new leaves had formed.
The water being well supplied with carbonic acid, and
a little of this gas again introduced into the graduated tube,
I left the experiment (in order to make a journey) until
the 18th September.
On the 18th September my Convolvulus had grown to
90 divisions ; and by the 30th of that month to 94 ; nearly
to the top of the tube.
On the 2nd October, it began to turn yellow, as did also
the two plants growing in water outside the apparatus as
" witnesses " ; they all three put on their autumnal tints
at the same time, and had ceased to vegetate by 30th
October.
The gas in the graduated tube (reduced to C. and
30 inches barometer) then measured 95 cubic centimetres.
It was analysed on the 30th October, and gave exactly the
following result:
Nitrogen, . '"' * 75 cubic centimetres.
Carbonic acid, . none
Oxygen, . 20
Total, V . 95
Thus in the course of three months and seven days, or
ninety-eight days, the little plant had grown from 30 to 94
divisions, not counting the curve, natural to the Convolvulus,
and had converted all the carbonic acid into oxygen, leaving
the nitrogen exactly as it was at the commencement of
the experiment.
APPENDIX A. 167
At the end of these fourteen weeks the atmosphere of the
graduated tube was richer in oxygen than ordinary atmos-
pheric air.
II. ADDITIONAL NOTES.
1. BUMBLING THUNDER. There is a curious passage in
Galvani's paper, De Viribus Electricitatis, etc., 1791
(Bologna), on the use of a frog's leg, properly prepared, as an
electrometer, or electroscope.
Dr. Galvani wished to try whether the electricity of the
atmosphere, or the clouds, would produce the same effect
on the prepared limbs of a frog as is produced by the
artificial electricity of ordinary machines. He had already
noticed, independently of the convulsions caused by the
direct contact of the limbs with the conductor of an electric
machine, that whenever a spark was taken from a large
conductor situated at some distance from the prepared
limbs, the legs moved with a kind of spasmodic contraction,
sometimes strong enough to cause them to jump a little.
In order to ascertain whether atmospheric electricity
would act in the same manner, he placed a conductor at
the top of his house in Bologna, and put this conductor
in connection with the prepared frog placed upon a table
in the open air, or enclosed under a glass bell, and he
soon observed that lightning produced the same effect
as the sparks of an electric machine at,, a little distance.
The same contractions of the limbs occurred, and they
were stronger, or weaker, according to the distance and
quantity of the lightning.
Thus far the effects might, naturally, have been expected ;
168 APPENDIX A.
but a remarkable circumstance was observed which seems
to explain another phenomenon of nature : it was found
that instead of one contraction at every clap of thunder,
the frog's limbs were affected with a sort of tremor, or
succession of convulsions, which seemed to be nearly
equal in number to the repetition of the thunder, namely,
that succession of explosions which cause the rumbling
noise of thunder. This observation, he imagined, proves
that the rumbling noise is not the repeated echoes of a
single explosion, as had been generally admitted, but
that it is produced by a quick succession of several ex-
plosions. This is, no doubt, very true; but the effect
of echo may likewise play its part, as Galvani himself
would have admitted could he ever have heard a pistol
discharged on a Ehine boat passing the famous Lurleyberg
on a fine summer day.
2. BOOMING NOISES IN THE AIR. I have, on more than
one occasion, whilst sitting of an afternoon on the sand-
hills of Ostend on hot, calm days of summer, heard booming
sounds in the air, just like the reports of distant cannon.
This subject gave rise, many years ago, to some correspond-
ence in certain geological journals, and it was sought to
prove that what I had heard so distinctly, was really due
to the sound of cannon, during artillery practice carried
by the water from the English or French coasts.
However, I have since met with accounts of similar
sounds being heard in South America, and in India, at
places where no sounds of cannon could by any possibility
be heard; and these singular booming sounds, which only
occur in the calmest weather, when there are no clouds,
APPENDIX A. 169
and no wind, still require explanation. At the time I
first heard them, I took every means of assuring myself
that they could not be due to ship's guns at a great distance,
or to artillery practice hundreds of miles distant. More-
over, I never heard them more than twice or three times
in an afternoon. Still, from the nature of the sound this,
in the present state of science, would be the only explana-
tion possible, had I not met with accounts by travellers
in South America, and India, of precisely similar effects
having been noticed by others under circumstances that
precluded the idea of their being reports of guns at a
great distance.
3. LATEST OBSERVATIONS ON ATMOSPHERIC ELECTRICITY.
A history of these observations is given in my work
Familiar Letters on Some Mysteries of Nature (1877), and
in my previous work Phosphorescence (1862). Since the
dates at which they were published, many thousands of
observations have been made, confirming all that is there
stated, but adding no new discoveries of importance. The
recent work of the Austrian philosophers, Elster and Geitel,
on the higher Sonnblick (about 10,000 feet above sea-level),
add little or nothing to what was known in the time of
Frangois Arago (Notice sur le tonnerre, 1838). They have
found, at this height, that in storm-clouds there is a change
in the sign of the electricity after every flash of lightning,
just as we observe in the plains or valley s % They also find,
that St. Elmo's fire is a constant accompaniment of storms,
and is sometimes positive and sometimes negative not more
frequently one than the other. Negative St. Elmo's fire
follows bluish lightning, and positive St. Elmo's fire follows
1 70 APPENDIX A.
reddish lightning. This fact was frequently confirmed ;
whence these observers conclude that the direction of the
electric current which traverses the atmosphere appears to
have an influence on the colour of the lightning.
To this I may add, that whenever I have witnessed a
stroke of lightning, it has always appeared as a red globe,
about the size of a cannon-ball, which, taken in connection
with the fact that the Earth is always negative, is worthy of
note. Nevertheless, it is known that the electric spark is of
various colours when passing through different gases, being
very white in carbonic acid, reddish or purple in hydrogen
or ammonia, etc. Hitherto, without the aid of direct
experiment, I have thought that blue lightning occurred in
dry air, and red lightning in wet air.
In 1889, M'Lean and Goto, in Glasgow, showed that an
enclosed mass of air is electrified negatively by the burning
of a paraffin lamp, coal-gas, sulphur, magnesium, and many
other substances. But the burning of charcoal electrified
a room positively. When ventilation is active no electriza-
tion of the air of a room is perceptible by these means,
4. SMOKE IN THE AIR OF TOWNS. Dr. Cohen of Leeds
has calculated that in that town alone, about one ton of
smoke is launched into the atmosphere every hour (the exact
figures found were twenty tons a day). A large amount of this
falls as soot, darkening the air, and fogs, and blackening the
skins of men and the leaves of plants. He finds in this
soot 14 to 15 per cent, of what he calls a "nasty, sticky oil,"
which has an unpleasant odour, and causes the soot to adhere
so firmly to the leaves of plants, that it requires an immense
amount of rain to wash it off. The carbon and coal-oil of
APPENDIX A. 171
soot, nevertheless, act as antiseptics, and are not so harmful
as many people suppose.
5. THE DUST THEORY OP KAIN. Of late years a new
theory has been put forth regarding the formation of mist,
fog, cloud, and rain. It is asserted that without dust in the
air that is, microscopic fragments of sand, sea-salt, organic
matter, etc. there would be 110 mist or rain. The starting-
point, it is said, of each drop of water is a minute nucleus of
dust- an infinitesimally minute fragment of salt or sand ;
" a microscopic speck of sand, around which the vapour of
water condenses,' 7 as a man puts on an overcoat. Without
this dust, which is always present in the lower atmosphere,
the vapour of water, on a cooling of the air, would be
deposited on the ground in sheets of dew that would soak
the buildings, and gardens, etc., but there would be no mist,
fog, or rain.
This theory is based upon a simple experiment, which con-
sists in exhausting some air from a large glass globe full of
moist air. If that air be perfectly free from dust, no mist
is formed when the air is thus cooled ; but if a little dust is
blown in, mist forms as soon as the piston is worked again.
It is probable, however, that electricity may be capable of
forming mist or fog in perfectly pure air saturated with
moisture. When ozone is passed through water into air,
confined in a glass vessel, a mist is formed in the latter,
whether there be any dust or not.
6. ODOUR OF THE ATMOSPHERE. In addition to what I
have already said on the odour of the air, experienced in
travelling from one country to another, on the odour of the
172 APPENDIX A.
air after a summer shower, on the fact that ancient fossils of
the tertiary period have revealed to me that sea-air had the
same odour as now in times excessively remote, I may record
here that, according to Dr. Varigny, the atmosphere itself,
which is generally considered to be inodorous, really has an
odour sui generis. In his opinion the air that usually
surrounds us is full of all kinds of scents and odours, but we
are so accustomed to them that they attract no attention.
But after spending some time in an atmosphere where the
most ordinary odours cannot gain access, and then returning
to our ordinary surroundings, the case is altered and a very
powerful odour is perceived. This fact has been noticed by
various observers who have sojourned for a considerable
interval in deep caves. The air of these caves is nearly
odourless, and when, after a few hours spent in this
"scentless air," the visitor emerges into the open air of the
country, he perceives that the atmosphere has a peculiar
and very intense odour, by which delicate people in these
particular circumstances have been, more or less, strongly
affected.
But, after all, it is not the atmosphere itself which affects
the olfactory organs in these circumstances, but the numerous
extraneous substances that are constantly present in its lower
strata. So that Dr. Varigny's supposition that the atmos-
phere has an odour sui generis is by no means proved.
7. FREE OXYGEN IN BIVER WATER. The amount of
free oxygen found in the air dissolved in river waters varies
according to the purity of the water. In the absence of
impurities, there is far more oxygen than when impurities are
present ; and we can determine the degree of purity of a
APPENDIX A. 173
river water by simply ascertaining the amount of. free oxygen
which it contains.
For instance, the Thames at some distance above London
yields 7*4 parts of free oxygen, at Hammersmith 4*7 parts,
at Somerset House 1'5, and at Woolwich 0'25. These figures
speak for themselves.
Most river waters yield from 4 to 8 cubic centimetres of
free oxygen gas per litre (or quart) of water, according to
circumstances. The more oxygen gas thus found, the purer
is the water, and better for drinking. The pure water of the
Khone, far from towns, will give 8*4 cubic centimetres of
oxygen gas to the litre of water, whilst the water of the
river Seine at Paris only yields 3*9 cubic centimetres.
8. IMPORTANCE OF THE FREE OXYGEN KATIO IN THE AIR,
In a recent pamphlet on Air and Life, Dr. Yarigny states that
living beings are adapted, at the present period of the life of
the globe, to exist in an atmosphere containing J of oxygen, and
f of nitrogen. Experience shows that if the ratio of oxygen
be decreased even by th part, life can no longer be main-
tained. Paul Bert has shown that a change in the contrary
direction is, also, most deleterious. If the oxygen acquires
a certain tension in the atmosphere or, what amounts to the
same thing, if it be present in a certain ratio above the
normal it becomes an agent of death, both for plants and
animals. This he demonstrated by causing plants or animals
to live in a normal atmosphere, but under a high degree of
pressure ; or by placing them in an artificial atmosphere
containing a large excess of oxygen. In both cases death
was the result.
174 APPENDIX A.
9. OZONE IN THE ATMOSPHERE. The absolute quantity
of ozone, or condensed oxygen (3 volumes condensed into
1), rarely exceeds 1 part in 10,000 parts of air.
Its presence is a fair guarantee of the purity of the
air, but an excess of ozone is deleterious to persons suffer-
ing from bronchitis.
Ozone has been liquefied at 100 C. below zero, with a
pressure of 127 atmospheres. It then forms a liquid of a
dark indigo-blue colour. Gaseous ozone, viewed endways
through a tube a yard long, also shows a blue colour.
10. WATER VAPOUR IN THE ATMOSPHERE. The average
quantity of water vapour in the air near sea level, in most
countries, is from 60 to 75 per cent, of that required for
complete saturation.
The phenomenon of the rainbow proves that rain-drops
are perfectly spherical in form ; for this phenomenon can
only arise from the regular dispersion of white light by
transparent globules of a perfectly spherical shape. In-
stantaneous photographs also show them as perfectly
globular in form.
Observations made, of recent years, from the earth, on
mountains, and in balloon ascents, have shown that the
tower of a cumulus cloud often exceeds 10,000 or 15,000
feet, and in great storms may be 25,000 to 40,000 feet from
base to summit.
11. LATEST CONSIDERATIONS ON "ARGON." Lord Kay-
leigh has said, " We are not able to state with certainty
whether argon is a mixture, or, if it be, of how many
elements it consists. The spectroscopic evidence points in
APPENDIX A. 175
favour of at least two components, but of itself is not
conclusive." And, again, " the density of argon is approxi-
mately 20."
This causes me to believe that argon may ultimately be
found to be a carbide of nitrogen, CN, having half the
quantity of carbon contained in cyanogen. Such a com-
pound would have a density of 20, and may yet be
artificially prepared in the laboratory. This, in spite of
the fact that considerations, derived from the specific heat
of this new gas of the atmosphere, show that it must be
considered an element, according to our present experience.
"Helium" is another gaseous body, which is still under
investigation by Dr. Ramsay, and this chemist has recently
(1898) found still another gas, which he calls " Crypt on"
(or "hidden"), and has obtained as a residue from the
evaporation of liquid air. He believes it is present in the
atmosphere to the extent of-1 part in 20,000 parts.
The new gas "Argon" is found to form about 1 per cent.
of our Earth's atmosphere, and, like nitrogen, has little or
no affinities for other substances. It was first seen by
Cavendish in the last century, and by Van Marum, a
Dutch chemist, when they subjected atmospheric air to the
action of the electric spark, with the view of obtaining
nitric acid. There always remained a residue in these
experiments, and this residue consisted largely of " argon,"
together with the other gases which had escaped the action
of the electric sparks. 1 ^
12. HIGH READINGS OF THE BAROMETER DUE TO THE
1 A letter published in the Chemical News of 17th June 1898 shows
that Rayleigh and Ramsay have really isolated no new elements, but
only mixtures of gases.
176 APPENDIX A.
MOON'S ACTION. I have sometimes been surprised at the
remarkably high, reading of the barometer extending over
a month or more in England, and Northern Europe gene-
rally, and independent of the direction of the wind or state
of the weather. Such was the case, for instance, in January
and part of February 1896. This phenomenon has been
carefully observed by Mr. Dechevrens, of Jersey (director of
the St. Louis Observatory in that island), and he attributes
it decidedly to cosmic influence, that is, to the position of
the Sun and Moon with regard to the Earth, and especially
to the distance of the Moon : the greater the distance of the
Moon the higher the glass stands, and the nearer the Moon
is to the Earth, the lower the barometer.
The Moon acts upon the atmosphere as it does upon the
ocean to produce the tides ; and the nearer our satellite
happens to be to the Earth the greater is its attraction,
and the lower the barometer.
By studying the fluctuations of the barometer since 1750
to the present time, Mr. Dechevrens has discovered that
this high reading has a period of 19 years, and in making
these researches he has, moreover, discovered a general
increase of atmospheric pressure having 63 years between
the maximum and minimum points, or a cycle of 126
years.
13. HYDROGEN GAS IN THE HIGHER EEGIONS OF THE AIR.
It will be remembered that one of our greatest chemists,
the late Professor T. Graham, who was for some time
Master of the Mint, discovered a small quantity of hydrogen
gas in meteorites (aerolites), composed chiefly of iron and
nickel, more especially on the Leanarto meteorite, which
APPENDIX A. 177
contains 90 parts of iron and 8 parts of nickel, with a
little cobalt. When heated in a porcelain tube a quantity
of hydrogen gas, amounting to about double the volume
of the meteorite, was obtained. Hence he concluded that
meteors traverse a region of the heavens in which hydrogen
gas is contained; and he calls attention to the fact that
the rays of hydrogen have been found in the spectra of
certain fixed stars, and in the sun.
The conclusion is not warranted, as this remarkable
aerolite was, like all others, at an excessively high tempera-
ture on passing through the air, and as our atmosphere,
at least in the lower regions, is abundantly supplied
with vapour of water, which would instantly be decomposed
on the aerolite entering these lower regions, the conclusion
is not necessary. It may be, also, that the hydrogen found
in his experiment was simply due to the absorption of
water into the pores of the -meteorite after it had fallen,
which water would be decomposed when the meteorite was
heated in the porcelain tube, and yield hydrogen gas.
14. ELECTRIC STATE OF THE AIR DURING CHOLERA
EPIDEMICS. We must not pass over the very interesting
results obtained by Professor Denza at the Observatory
of Moncalieri in Italy, during an outbreak of cholera,
which was very severe at Turin and other towns of
Piedmont in 1867.
These observations on atmospheric electricity by Denza
were commenced regularly in December 1866, and were
the first regular researches of this kind carried on in
Northern Italy since Beccaria made the first experiments
on the electricity of the air in fine weather about the
M
178 APPENDIX A.
year 1775, in the days of Benjamin Franklin and De
Saussure.
In these researches the tension of the atmospheric
electricity was determined by Denza with the bifilar electro-
meter of the late distinguished Professor Palmieri, of the
Royal University of Naples. During the months of August
and September 1867, when the outbreak of cholera was at its
height in Turin, the electric tension of the air fell to almost
nothing, except on two days when there occurred storms
(temporali).
15. LIQUID AIR. The liquefaction of gases by the appli-
cation of cold and pressure combined has occupied many
experimentalists for the last century, or more. It has now
culminated in the liquefaction of atmospheric air by Pro-
fessor Dewar of the Royal Institution.
The curious chemical properties of this new fluid have
been alluded to already, but its physical property as a
motor power is no less wonderful.
Liquid air is simply the air we breathe compressed in a
series of cylinders, each successive cylinder pressing the air
into a smaller and smaller compass, the air after each pressure
passing through cooling tanks until, finally, when squeezed
into about g^th of its original volume and cooled to about
312 below the freezing-point of water, it changes from a
gaseous state into a liquid.
When this liquid is again exposed to the ordinary tempera-
ture of our rooms or streets, it expands to its original volume
with such power and rapidity as to exert a pressure of more
than 12,000 Ibs. to the square inch, which is a truly explosive
force exceeding that of dynamite itself.
APPENDIX A. 179
One gallon of liquid air weighs 7 Ibs., and we are assured
that, in round figures, about 1 Ib. of coal is required to make
1 Ib. of liquid air. Hence it must be a very economical
source of power.
It has been asserted that one cubic foot of liquid air will
develop, on gradual expansion, 5J horse-power per hour, or
1 horse-power for 5 J hours ; and it is believed by some
practical men, that this enormous power will soon supersede
steam, electricity, and all other sources of power, and that it
can be controlled and managed as easily as any of them.
To make liquid air is one thing, but to devise machinery
for its utilization as a motor power is another ; but both these
results, I am told, have been recently carried out by an
Anglo-American firm, which has already placed on our streets
motor cars driven by the gradual expansion of liquid air
confined in a powerful cylinder; and there seems some
probability of liquid air being produced cheaply in large
quantities and applied economically as a motor power in
various branches of industry.
16. FIELD LIGHTNING. I find that the singular pheno-
menon described in my Mysteries of Nature as Field light-
ning, and alluded to in Chapter IX. of the present work, has
been witnessed in Mongolia as well as in the Jura Mountains.
Mr. A. B. Freeman Mitford, C.B., in a work on Peking, issued
quite recently, describes a storm he experienced in Mongolia
on 7th May 1867. He says : " About two njiles from Llama
Miao, where the storm had lashed itself to its greatest fury,
we came to a small plateau surrounded by low hills. Here
we witnessed a phenomenon, new to me, and which I
certainly never wish to see again. The thunder, which
i8o APPENDIX A.
seemed to circle round the hills, roared savagely and cracked
with deepening peals, while the lightning ran along the ground,
criss-crossing in every direction, until the little plain was
covered with a perfect network of Hue liquid flames, from the
meshes of which escape seemed impossible"
APPENDIX B.
Outlines of a New Atomic Theory.
By Dr. T. L. PHIPSON, F.C.S., etc. ; read at the British
Association for the Advancement of Science, Sept. 1886.
IN what follows, the term phlogiston is used in a somewhat
different sense to that in which it was employed by the
older chemists. Some other term might have been equally
acceptable, but this one already belongs to chemistry, and
therefore we have a predilection for it.
On a general survey of organic and inorganic nature, our
attention is arrested by a number of facts, which, though
they have hitherto defied explanation, the present considera-
tions appear to account for, so far as we can account for
anything by connecting facts with theory. Nevertheless,
the theory we now put forth does not necessitate any great
change in the nomenclature or teaching of chemistry ; if it
represent truth, it should be given to the world, though
for many years we have hesitated to publisji it.
In chemistry we have an immense list of substances, all
of which present themselves as colourless fluids, or white
powders, though differing as widely in their properties as
pure water and prussic acid on the one hand, or arsenious
182 APPENDIX B.
acid and sugar on the other. Wine-glasses filled with
water, alcohol, ether, sulphuric acid, solution of potash,
etc., present no difference to a child or a savage ; neither
would their contents be considered anything else than
water if they contained a solution of some nitrate, chlorate,
sulphate, sugar, strychnine, veratrine, ammonia, cyanide of
mercury, and so forth. In like manner, all the metals
present what is termed the "metallic aspect"; they all
show a great similarity of physical and chemical properties,
so that tin, silver, cadmium, zinc, antimony, sodium, mag-
nesium, aluminium, lead, etc., would readily be mistaken
one for the other by a child or inexperienced person.
Again, the alkaloids, sugars, glucosides, essences, etc., all
present a great similarity in their physical and chemical
properties, a likeness which extends to their therapeutic
qualities also.
Another fact, which has often struck chemical philoso-
phers, but has hitherto baffled all attempts at explanation,
is that of all the numerous elements, or simple bodies,
which compose our globe, four alone are found sufficient
to build up the whole of organic nature, and to form the
thousands upon thousands of substances known as organic
compounds.
One more fact, which is amply demonstrated by the
numerous analyses given in one of our works, is that
meteors or aerolites coming from distant regions of space
bring no unknown matter to our globe ; they are composed
of the same materials as our earth. It will be seen by
what follows that the same materials may possess different
properties, according to the circumstances in which they
are placed.
APPENDIX B, 183
A phenomenon, readily explained by our new atomic
theory, though it has hitherto not been accounted for
satisfactorily by any hypothesis, is that observed when two
substances of heterogeneous natures, such as two metals,
are brought into contact, an electric current, or electric,
calorific, or magnetic manifestations, immediately occur.
The old notion that matter is composed of " atoms and
spaces" is doubtless correct, and it can be argued success-
fully that atoms are extremely minute spheres. When one
substance is divided by another (as when an apple is cut
by a knife), the latter passes between the atoms, for matter
is impenetrable, that is to say, the same space cannot be
occupied at the same time by two groups of matter or by
two substances ; one must make room for the other, and
the space betiveen the atoms is what we designate as
phlogiston.
The whole question of the atomic constitution of matter
is contained in the theory of equal gaseous volumes, or
better, of the combining volumes of matter in the state of
gas. When we consider this subject, we are met at once
by a dilemma. Physical experiment having shown that
between certain limits of temperature equal gaseous volumes
dilate or contract equally for equal amounts of heat or
pressure, it was argued that equal volumes of gases contain
the same number of atoms of the same size and placed at
the same distance apart. This, of course, implies that the
atoms are of different weights (for instance, the atom of H
weighing 1, that of N weighs 14, etc.).
But it soon came to be seen that this could not be, because
in equal volumes of certain compound gases we know that
there cannot be an equal number of atoms.
i84 APPENDIX B.
The next supposition was that the atoms in equal gaseous
volumes may be of different sizes. Thus the atom. of H
would be 14 times smaller than the atom of N, etc. There
is nothing to be said against this hypothesis, except that
it does not explain anything ; it merely asserts that the
atom of N is 14 times as heavy as the atom of H, because
it contains 14 times more matter. This notion is, on many
accounts, improbable, unphilosophical, and explains nothing.
But another proposition, which we shall now put forward,
does explain a number of phenomena that otherwise we
find it impossible to account for.
This proposition is that equal gaseous volumes contain a
different number of atoms all of the same size and same
weight. This implies that the atoms are all of the same
nature, and proclaims the unity of matter.
Whatever substance may be under consideration, its
atoms are all of the same nature, and they are separated
by space, which we call phlogiston, a term that implies
movement, light, heat, electricity, etc. The greater the
amount of phlogiston the greater the energy of the system
of atoms termed element. Thus H is the most energetic
system of atoms yet known ; it has the greatest amount of
phlogiston; in other terms the motion of its atoms is the
most extensive.
The matter of all the elements is therefore identical ; the
phlogiston alone varies, that is, the distance or space between
the atoms (considered at rest), or their extent of motion.
A chemical element is therefore a system of atoms, the
nature or properties of which system depends on its
phlogiston, and the amount of the latter is deduced
directly from the balance from the weights which combine
APPENDIX B.
together. Thus in equal gaseous volumes of
we admit that there exist, say, 10, 140, 350 atoms of the
same size, same weight, and same nature ; and if we could
volatilize without decomposing solid bodies such as sulphate
of iron, for instance, so as to consider them under the same
gaseous volume, we should find the same law hold good
for them, and that an equal gaseous volume of ferrous
sulphate, for example, would give, as compared with the
substances above-named, 760 atoms of the same nature as
those of H, N, or Cl.
It will be seen by this that the properties of a substance
depend not on different kinds of matter, but on the different
amounts of phlogiston that separate the atoms and cause
them to move in certain set systems. The atomic system
called H is different from the atomic system called N,
because the atoms of the latter system are separated by
less space; the system possesses less phlogiston.
We thus see that, as everything depends on gravitation,
the systems of atoms (elements) known as iron, oxygen,
sulphur, etc., on this globe, may possess very different
properties on the planets Venus or Jupiter, for instance,
on account of the different distances of these planets and
our globe from the sun.
Spectral analysis, like the fall of aerolites, proves that
the same nature of atoms exists in far-off globes as with
us ; but we see that the properties of a substance depend
on its phlogiston, which in its turn depends on gravitation,
so that although the matter is identical with that of our
earth, the physical and chemical properties must be different
from what they are upon this globe.
We also see how the whole organic world is made up of
1 86 APPENDIX B.
a few systems of atoms (elements) only; they are those
which contain the most phlogiston, and consequently possess
the most energy; they constitute the nearest approach to
vitality.
Again, when two heterogeneous systems of atoms are
brought in contact, a vibration ensues such as astronomers
have termed perturbation ; it is caused by a slight deviation
of the movement a slight change in the phlogiston (which
may be temporary or permanent), and is carried away
along a "conductor," in the form of what is called an
electric current, or otherwise. In allotropic bodies the
original phlogiston is more or less permanently modified ;
and could this allotropism be pushed far enough, the
" transmutation " of the elements would undoubtedly ensue.
It will be perceived that this theory explains a mass of
facts, which are not even alluded to in the foregoing notes ;
and though it leaves unaccounted for a certain number of
physical phenomena, these will probably be explained in
time without disturbing it.
INDEX.
ABSORBING power of the atmos-
phere, 39.
Aerolites, phenomena of, 135,
136.
Air, compressed or rarefied, in
medical treatment, 83, 84, 173.
its disinfection, 85, 8fi.
electrified by combustion of
paraffin, etc., 170.
history of discovery of the
gases in, 4.
gun, 82.
hot and cold, 96.
of inhabited districts, 89.
at sea off coast of Flanders,
34.
of sea coast, 90.
liquid, 40, 178.
phosphorescence of, 51.
sudden vibration of, 53.
not an oxide of nitrogen, 33.
variations of quality at
Palermo, 30, 80.
variations during cholera,
30, 105, 177.
Algse in first fall of snow, 61.
unicellular, as producers of
oxygen, 26.
Alps, air of the, 104, 105.
phosphorescence of snow on
the, 52.
Altitude attained by British
troops, 119 (note).
best in India for Europeans,
98.
Altitude, total, 75.
Ammonia, its quantity in country
air, 71.
a volcanic product and a
secretion, 36.
and nitric acid, 35, 36.
Anaerobic beings, 13.
cells, their transformation,
27.
ferments, 15.
Analyses of air, 30, 89.
Andre, Ch., observations in a
balloon, 49.
Anglo-Indian statistics, 97.
Animal life, dawn of, 26.
Antirrhinum, author's experi-
ments with, 20.
Apophyllite, ammonia in, 37
(note).
Arctic regions, air of, 104.
Argon, the gas called, 8, 91, 174.
Arsenic, its danger as used by
mountaineers, 103.
Atlantic, atmospheric perturba-
tions of, 133.
Atmosphere of Cape Horn, 86.
an unexplained condition of,
55.
definition, 38.
its height above sea-level,
74, 76.
old opinion on its extension,
139.
the primitive, 19.
in remote geological periods,
9.
of our present epoclj, 32.
188
INDEX.
Atmosphere, the science of the, 1.
its temperature at great
altitudes, 78.
the term, 89.
Atmospheric tides, 158.
mucilage, 59.
oxygen, 18.
Atomic theory, a new, 25, 181.
Aurora borealis, 51.
effects on the magnet, 160.
Auroral arch, 130.
B
BACTERIA, their place in nature,
28.
of the Arctic regions, 86.
collected on cotton-wool, 71.
and micrococci, fossil, in the
air, -62.
Barometer, history of, 7.
its fall, as we rise in the
air, 76.
high readings of, 175.
rules for the observation of,
146.
wind, chief cause of its
movements, 110.
and < thermometer, opposite
indications, 107.
Baudrimont, his opinion on the
atmosphere, 14.
Bayen, his experiment, 6.
Beccaria, his knowledge of phos-
phoric phenomena, 52.
Bedrooms, the air of, 101.
Berlin, Dr. A., researches on
snow-blindness, 56.
Bert, Paul, observations on effects
of air pressure, 173.
Berzelius, his views on the ancient
atmosphere, 10.
his proof that air is a mix-
ture and not a compound, 33.
Birds, migration of, 66.
Blood, effects of mountain air on,
73, 74.
Bloody-finger grass, 68.
Booming noises in the air, 168.
Boussiugault, curious observation,
63, 64,
Breathing affected by mountain
air, 73.
Breweries, the air of, 102.
Briquet a Air, the, 53, 82.
Bran, account of his experiment
on air, 5.
CAMPI, his discovery of marsh
gas, 100.
Captive balloon experiments, 77,
78.
Carbon fixed in the earth, 13.
as carbonic acid in the
atmosphere, 90.
Carbonic acid could never have
predominated, 26.
quantity of, issued by a
chalybeate spring, 12.
amount of, in music halls, 90.
in London fog, 99.
quantity in the earth's
atmosphere, 14.
a volcanic product, 26.
Cavendish, his experiment on air,
92.
Characin, cause of odour of
marshy lands, 42.
Charles, Prof., attempt to arrest
the progress of a thunderstorm,
156.
Chemistrj 7 , dawn of scientific, 2.
Cholera epidemics, air in, 30, 1*05,
177.
Cirrus cloud, 122.
Climate for invalids, 87, 99.
Cloud, its formation, 77.
height of, 79.
checks radiation, 97.
Clouds, their formation, nature
and forms, 121.
Cloud-arch, curious phenomenon
of the, 128. , tjCA
Coal flora, 26. v "\~
Cold air more dangerous than hot
air, 96.
Colladon, Daniel, his use of com-
pressed air, 82.
Colour of atmospheric air, 40,
117.
INDEX.
189
Coloured circles (not halos), as
indicators of weather, 124.
Combustion, ancient views of, 3.
Consumptive subjects, best air
for, 99.
Convolvulus, author's experi-
ments with, 20, 163.
Cosmic dust, 66.
Cumulus cloud, 123.
Currents, aerial, 106, 115.
Curve of average temperature, 133.
Cyclones, their discovery, and
nature, 111.
local, 114.
D
DALIBARD, his experiment on
lightning, 48.
Davaine arid Pasteur, their obser-
vations, 142.
Dawn of animal life, 26.
De Foe, his suggestion of circular
storms, 111.
Denza, electric observations, 177.
Dewar, liquefaction of air, 40, 178. -
Digitaria sanguinalis, 68.
t Disinfection of impure air, 85.
of hospital wards, 101.
Dissard, A. 0., effects of change
of medium, 29.
Diurnal oscillations of the atmos-
phere, 108.
Dove, his " Law of Storms," 115,
117.
Dry fog, 154.
Duchesne, his first glimpse of
nitrogen, 3.
Dumas, J. B., his calculations,
10-11.
Dust, analysis of, 61.
raised by postilions, 50.
of snow, 126.
theory of rain, 171.
E
ECK VON SULZBACH, CUHOUS
experiment, 300 years before
Lavoisier, 6.
Egypt, culture of opium in, 105
(note).
Electric dust, 50.
light from hats of travellers,
50.
spark, colour of, 170.
state of the air during
cholera, 177, 178.
state, fluctuations of, in the
atmosphere, 108.
Electricity, atmospheric, 48, 169,
108, 177.
currents of, obtained from
the air, 49.
produced by condensation
of vapour, 125.
Elements, the, of the Ancients, 5.
Elster and Geitel, observations by,
169.
Epidemics, 143, 177.
Eremacausis of organic matter, 16.
Esquimaux, ; their "snow eyes,"
57.
Expansion of air by heat, 108.
Explosions in coal mines, cause
and remedy, 101.
of meteors, experiment by
the author, 67.
FALL of sulphur during a storm,
42.
Falls of foreign bodies through
the air, 59.
Faraday, his experiments on
gases, 40.
discovery of magnetic pro-
perty of oxygen, 159.
Fermentation, the air of, 101.
Ferments collected from the air,
71, 72.
their place in nature, 28.
Field lightning, 50, 179.
Figures of sun and moon dis-
torted, 117.
Fitz-Roy, his observations, 77, 78.
rules for the barometer, 146.
" Weather Book," 115.
Flora and Fauna of the earth, 9.
Fog of Dec. 27, 1813, 153.
190
JNDEX.
Fogs, carbonic acid in, 99.
electric nature of, 51, 153.
in London, 70.
^Forests, air of, 93.
Fossil microbes, 62.
Teredo, 44.
Franklin, his celebrated experi-
ment, 48.
Frogs transported by waterspouts,
69.
Fungi, the class of, 28.
G
GALILEO, his discovery of the
weight of air, 6.
Galvani, remarkable experiment
by, 167.
Gautier, A. (see Hydrogen).
Glare, its nature discussed, 55.
Goethe, his observations at Gir-
genti, 129.
Gossamer, 65.
Grass, bundles of, transported
through the air, 63.
' ' Green matter " of water exposed
to sunlight, 142.
Grotta del Cane, near Naples, 99.
Gulf stream, 114, 131.
H
HAIL, the phenomena of, 127.
damage by, in France, 156.
Halos, solar and lunar, 62.
Hsematosis, 73, 103.
Hartz mountains, 118.
"Health resorts," 87.
Heat, the "soul of the universe,"
106.
Height of the atmosphere dis-
cussed, 74, 76.
to which man can live, 75.
Hemeralopia, or night-blindness,
57.
Hoar frost, nature of, 126.
Hoefer, F., on the apparition of
plants, 13.
Holothuria, respiratory functions
of, 15.
Hooke, Dr., detection of oxygen
in 1665, 3.
Houzeau, his theory of thunder-
storms, 125.
his weather table, 147, 150.
Humboldt, an argument by, 13.
observations on the snow
line, 120.
Hydrogen gas in the higher
regions of air, 176.
(A. Gautier, by passing sea
air over red hot copper oxide,
pretends to have found 2 vols.
of hydrogen in 10,000 vols. of
air.)
vegetation in, 21.
I J
ICE CRYSTALS, fall of, 62.
Ignis fatuus, 100.
Immediate weather, 145, 147.
Insects transported by the air,
65.
Iron particles discovered in the
atmosphere, 61.
Julienne, his air machine, 82, 83.
Junod, Dr., his use of rarefied air,
83.
K
KEELER, Prof., on Saturn's ring,
^138.
Kepler, his magnetic discoveries,
160.
Koene, Prof. C. J., on changes in
the atmosphere, 10.
Krakatoa, eruption of the volcano,
66.
LAMARCK, views of, 13.
Langley, experiments on the
Californian mountains, 39.
Lavoisier, his first analysis of the
air, 4.
Levy, analyses made by, 34.
Liebig, on the composition of the
atmosphere, 10.
INDEX.
191
Light from crystallization, 53.
phosphoric, in the air, in
snow, etc., 50, 53.
Lightning conductors, discovery
of, 50.
drawn from the air, 156.
flash, its cause, 52.
on the ground, 50, 179.
stroke on a captive balloon,
50.
stroke on the earth, 135,
136.
Liquefaction of atmospheric air,
40.
Liquid air as a motor power, 178.
Local cyclones, 114.
London fog, substances present
in, 70.
Luminous fogs, 154, 155.
- meteors, height at which
they shine, 75.
M
E, experiment by, 50.
Macagno, Prof., analysis of air at
Palermo, 80.
Magnetic conditions of the at-
mosphere, 159, 161.
Mairan, his prize essay on the
barometer, 110.
Maize killed by blight, 105.
Marcet, Dr., experiment on re-
spiration, 99.
Marsh gas, 100.
Martins, Ch. , respiration of plants
and animals, 11.
Maury, researches of, 131.
- his hypotheses, 158.
May, cold days of, 98.
Mayow, his celebrated pamphlet
on oxygen, 3.
Meissner, Dr., experiment on
electrified air, 155.
Meteoric dust in the Arctic re-
gions, 67.
Meteors, aerolites and falling
stars, 61.
- history of, 136.
- cause of their explosion, 67.
Miasma and Virus, 141.
Microbes, 86, 87, 141, 143.
Mines, air of, 100.
Mirage seen in England, 103.
Moisture, quantity in the air, 79.
Monocellular organisms, 143.
Moon, its influence on the atmos-
phere, 158.
action on the barometer, 176.
Mountain air, 73, 103.
Movements of the atmosphere,
106.
Mulder, on changes in the atmos-
phere, 11.
N
NAPHTHA, vapour distinguished
from marsh gas, 100.
Nervous system, its increase with
that of oxygen, 14.
Night blindness in Franco-Prus-
sian war, 57.
Nimbus, or rain cloud, 123.
Nitrification, its explanation, 36
.Nitrogen, first glimpses of, 3, 4.
the primitive atmosphere of
the earth, 25.
the nature of, 35.
supposed extraction from air,
13.
Nostoc commune, 68.
ODOUR of the atmosphere, 171.
air in beech and pine forests,
44.
air after a stroke of lightning,
41.
air of foreign countries, 42.
in the air of marshy lands,
43.
of sea air, 44.
after a summer shower, 45.
of fossil Teredo^ 44.
Odours before thunderstorms, 53.
Opium culture in Egypt, 105
(note).
192
INDEX.
Optical phenomena of the atmos-
phere, 117.
Organic matter of the atmosphere,
140.
Origin of aerolites, 137.
Oscillations of atmospheric pres-
sure, 108.
Overcasting, sudden, 121 (note).
Oxygen, its discovery, 4.
its absence from the primi-
tive atmosphere of the globe,
10, 25.
its appearance in the primi-
tive atmosphere, 19, 25.
(free) in river water, 172,
173.
Ozone, its nature and effects, 45.
liquid, 174.
PARIS hospitals, disinfection of
air in, 85.
Pasteur, discovery of anaerobic
ferments, 15.
and Davaine, 142.
Pelouze, his views on the atmos-
phere, 14.
Peltier, his observations on fogs,
154.
Period that will never be de-
termined, 28.
Periodic plants, 68.
Perpetual snow and ice, 120.
Phipson, Wilson \V., his en-
gineering works, 81.
Phlogiston, new signification of,
181.
Phosphorescence of the air, 51.
rain drops, 118.
work on, 52.
Piazzi - Smyth, experiment at
Teneriffe, 39.
rain band of the spectroscope,
80.
Planets, their effects on our
atmosphere, 97.
Plants, anaerobic, 18.
first producers of oxygen, 12.
experiments on the growth
of, in various gases, 19, 163.
Plants, microscopic hairs of, 62.
Primitive atmosphere, the, 19.
conditions of the globe, 25.
Protococcus as a producer of oxy-
gen, 13.
respiratory functions of, 15.
Pyrites in hailstones, 67.
R
RADIATION effects, 95, 97.
Rain band of the spectroscope, 80.
dust theory of, 171.
fall, influence of forests on,
95.
fall, its quantity, 151.
frozen, 104, 126.
"of sulphur,'* the so-called,
69.
without clouds, 104 (note).
Rapidity of motion of the air, 109.
Rayleigh and Ramsay, discovery
of " Argon," 92, 174.
Refraction of light, its effects, 117.
Refrigeration of the atmosphere,
77.
Reiset, his analyses of air, 14.
"Residues" left in primitive
times, 9.
Respiration in lower forms of
life, 15.
equilibrium of plants and
animals, 11.
Richman, Prof., death by light-
ning, 48.
Romas, De, experiments on at-
mospheric electricity, 156.
Ronayne, Thomas, his discovery
of the electric nature of fogs,
154.
Rotation of the vane, 107.
Rumbling thunder, 167.
SABINE, auroral arch, 130.
results of his observations,
160.
INDEX.
193
Salt in the atmosphere, 64.
rain, 102.
Saltpetre, its formation, 36.
Saussure, Benedict de, experi-
ments of, in 1767, 49.
Theodore de, researches of,
23.
Schiaparelli, opinion on comets,
138.
Schlagintweit, the brothers, alti-
tude attained by, 119.
Schroeder and Dusch, observa-
tions by, 141.
Schultze, his experiments, 141.
Schwann, experiment on air, 141.
Science of the atmosphere, the, 1.
Sea, the air of the, 102.
Smoke of towns, 170.
Snow-blindness, 56.
Snow, formation of, 126.
Snowfall in a dining-room, 127
(note).
Snow line, the, 120.
Social mites, mysterious appari-
tion of, 66.
Sound, conduction by air, 73.
Spectral lines of oxygen, 39.
Spectre of the Brocken, seen in
London, 118.
Spiders' webs in the air, 65.
Stagnant waters, air over, 100.
"Star jelly, "60.
Star shower of Nov. 1866, 51,
61.
Stars, shooting, 138.
St. Elmo's fire, 118.
positive and negative, 169.
St. Hilaire, Geoffrey de, his
views, 13.
Stone, fragments of, which fell in
Birmingham, 69.
Stratus cloud, 123.
Sulphate of soda in the lower
atmosphere, 64.
Sulphur always present in the
air, 41.
" Sulphur rain," 42.
Sunsets, gorgeous, 66.
Symons, his researches on British
rainfall, 151.
Symptoms observed at great
altitudes, 119.
TELEGRAPHING the weather, 145.
Temperature, curve of average,
133.
at great altitudes, 78.
affected by position of the
planets, 97.
Thames water, free oxygen in,
173.
Thermometer, how to observe
the, 97.
for ascertaining altitudes,
176.
dry and wet bulb, 79.
" Thunderbolts, "135.
Thunder-clouds, 156.
Thunder-storms, electric tension
in, 49.
means of avoiding their
effects, 155.
Thunder, rumbling of, 167.
Tides, atmospheric, 158.
Tin and mercury in experiments
on air, 5, 6.
Torricelli, originator of the baro-
meter, 7.
Transparency of the air, 38.
Transportation of germs, 142.
Treeless plains, the air of, 103.
Trees, their influence on air of
towns, 94.
Tropics, air of the, 105.
Tunnels of the Alps, 82.
U V
UREA ferment in street air, 71.
Ventilation, 81.
Vesicular theory, 122.
Viault, Dr., his remarkable dis-
covery, 74.
Vibration of t}ie air, 53.
Virigny, Dr., air and life, 172.
Vitality, its increase with that of
oxygen, 16.
Volcanic action, 11.
ash, 66, 69.
effects on sunsets, 66.
Volcanoes, the air over active,
102.
N
194
INDEX.
W
WARTMANN, Prof. , on a luminous
fog, 155.
Water, its boiling point at various
altitudes, 77.
discovery of its composition,
5.
sterilized, 142.
vapour in the air, 79, 174.
Waves of pressure, 111.
Weather forecast by cloud obser-
vations, 123.
forecast for the day's tem-
perature, 97.
of a given locality, 145.
Weather table, 147.
Weight, absolute and relative, of
the air, 110.
of the entire atmosphere,
how found, 116.
Wells and sewers, the air of, 102.
Will-o'-the-wisp, 100, 101.
Wind motor of Rollaston, 83.
prodigious effects of, 110.
warm and cold, effects of,
107.
YELLOW- FEVER, altitude to which
it extends, 98.
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THE DESIGN OF STRUCTURES:
A Practical Treatise on the Building of Bridges, Roofs,
BY S. ANGLIN, C.E.,
Master of Engineering, Royal University of Ireland, late Whitworth Scholar, &c
With very numerous Diagrams, Examples, and Tables.
Large 8vo. Cloth.
SECOND EDITION, Revised. 16s.
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1. It supplies the want, long felt among Students of Engineering and
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the reader a knowledge of ELEMENTARY MATHEMATICS only.
2. The subject of GRAPHIC STATICS has only of recent years been generally
applied in this country to determine the Stresses on Framed Structures ; and
in too many cases this is done without a knowledge of the principles upoB
which the science is founded. In Mr. Anglin's work the system is explained
from FIRST PRINCIPLES, and the Student will find in it a valuable aid in
determining the stresses on all irregularly- framed structures.
3. A large number of PRACTICAL EXAMPLES, such as occur in the every-day
experience of the Engineer, are given and carefully worked out, some being
solved both analytically and graphically, as a guide to the Student.
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Joints, Punching, Drilling, Rivetting, and other processes connected with the
manufacture of Bridges, Roofs, and Structural work generally, are the result
of MANY YEARS' EXPERIENCE in the bridge-yard ; and the information given
on this branch of the subject will be found of great value to the practical
bridge-builder.
" Students of Engineering will find this Text-Book INVALUABLK ." Architect.
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TEXT-BOOK on the subject, but also to the professional engineer as an HXCKKDINGJLT
TALUABLK book of reference," Mechanical World.
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chosen to use as little of the higher mathematics as possible, and has thus made his book of
XKAL USK TO THB PRACTICAL ENGINEER. . . . After careful perusal, we have nothing bwt
praise for the work." Nature.
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A PRACTICAL TREATISE ON
BRIDGE-CONSTRUCTION:
Being a Text-Book on the Construction of Bridges in
Iron and Steel
FOR THE USE OF STUDENTS, DRAUGHTSMEN, AND ENGINEERS.
BY T. CLAXTON FIDLER, M. I N s T. C. E.,
Prof, of Engineering, University College, Dundee.
GENERAL CONTENTS.
PART I. ELEMENTARY STATICS: Definitions The Opposition and
Balance of Forces Bending Strain The Graphic Representation of Bending
Moments.
PART II. GENERAL PRINCIPLES OF BRIDGE-CONSTRUCTION : The
Comparative Anatomy of Bridges Combined or Composite Bridges
Theoretical Weight of Bridges On Deflection, or the Curve of a Bended
Girder Continuous Girders.
PART III. THE STRENGTH OF MATERIALS : Theoretical Strength of
Columns Design and Construction of Struts Strength and Construction of
Ties Working Strength of Iron and Steel, and the Working Stress in
Bridges Wohler's Experiments.
PART IV. THE DESIGN OF BRIDGES IN DETAIL : The Load on
Bridges Calculation of Stresses due to the Movable Load Parallel Girders
Direct Calculation of the Weight of Metal Parabolic Girders, Polygonal
Trusses, and Curved Girders Suspension Bridges and Arches : Flexible
Construction Rigid Construction Bowstring Girders used as Arches or as
Suspension Bridges Rigid Arched Ribs or Suspension Ribs Continuous
Girders and Cantilever Bridges The Niagara Bridge The Forth Bridge
Wind-Pressure and Wind-Bracing : Modern Experiments.
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8IMPLICITT OF TREATMENT displayed on every page. . . . Theory is kept in
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M to students of Bndge Construction." The Architect.
" Of late years the American treatises on Practical and Applied Mechanics
have taken the lead . . . since the opening up of a vaat continent has
giyen the American engineer a number of new bridge -problems to solvt
. . but we look to the PRESENT TREATISE ON BRIDGE-CONSTRUCTION, and
the Forth Bridge, to bring us to the front again." Engineer.
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application to Bridge-Construction. . . Well repays a careful Study. "-
Engineering.
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GAS, OIL, AND AIR ENGINES:
A Practical Text - Book on Internal Combustion Motors
without Boiler.
BY BRYAN DONKIN, M.INST.C.E., M.INST.MECH.E.
THIRD EDITION, Revised throughout and greatly Enlarged. With
numerous additional Illustrations. Large 8vo, Handsome Cloth.
GENERAL CONTENTS. Gas Engines: General Description History and Develop-
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Theory of the Gas Engine Chemical Composition of Gas in Gas Engines Utilisation of
Heat Explosion and Combustion. Oil MotOPS : History and Development Various
Types Priestman's and other Oil Engines. Hot-AiP Engines : History and Develop-
ment Various Types: Stirling's, Ericsson's, &c., &c.
"The BEST BOOK NOW PUBLISHED on Gas, Oil, and Air Engines. . . . Will be of
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PRACTICAL EXPERIENCE, Combined with HIGH SCIENTIFIC AND EXPERIMENTAL KNOWLEDGE,
and an accurate perception of the requirements of Engineers." The Engine fr^
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In Quarto, Handsome Cloth. With Numerous Plates. 253.
THE HEAT EFFICIENCY OF STEAM BOILERS
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With many Tests and Experiments on different Types of
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Analyses of Gases and Amount of Evaporation,
and Suggestions for the Testing of Boilers.
BY BRYAN DONKIN, M.INST.C.E.
GENERAL CONTENTS. Classification of different Types of Boilers
425 Experiments on English and Foreign Boilers with their Heat Efficiencies
shown in Fifty Tables Fire Grates of Various Types Mechanical Stokers
Combustion of Fuel in Boilers Transmission of Heat through Boiler Plates,
and their Temperature Feed Water Heaters, Superheaters, Feed Pumps,
&c. Smoke and its Prevention Instruments used in Testing Boilers
Marine and Locomotive Boilers Fuel Testing Stations Discussion of the
Trials and Conclusions On the Choice of a Boiler, and Testing of Land,
Marine, and Locomotive Boilers Appendices Bibliography Index.
With Plates illustrating Progress made during the present Century,
and the best Modern Practice.
"A WORK OF REFERENCE AT PRESENT UNIQUE. Will give an answer to almost any
question connected with the performance of boilers that it is possible to ask." Engineer.
" Probably the MOST EXHAUSTIVE resume* that has ever been collected. A PRACTICAL
BOOK by a thoroughly practical man." Iron and Coal Trades Review.
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ENGINEERING AND MECHANICS. 29
In Crown 8vo, extra, with Numerous Illustrations. [Shortly.
GAS AND OIL ENGINES;
AN INTRODUCTORY TEXT-BOOK
On the Theory, Design, Construction, and Testing of Internal
Combustion Engines without Boiler.
FOR THE USB OF STUDENTS.
BY
PROF. W. H. WATKINSON, WHIT. Son., M.INST.MECH.K,
Glasgow and West of Scotland Technical College.
THIRD EDITION, favited and Enlarged. Pocket-Size, Leather, 12*. Bd.; alto Larger Sin for
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Boilers, Marine and Land:
THEIR CONSTRUCTION AND STRENGTH.
A HAITDBOOK 0* RULES, FORMULA, TABLES, &c., RELATIVE TO MATERIAL,
SCANTLINGS, AND PRESSURES, SAFETY VALVES, SPRINGS,
FITTINGS AND MOUNTINGS, &a
FOR THE USE OF ENGINEERS, SURVEYORS, BOILED-MAKERS^
AND STEAM USERS.
BY T. W. TRAILL, M. INST. 0. E., E. E. K N.,
Late Engineer Surrtjor-in-Chief to the Board of Trad*.
%* To THE SECOND AND THIRD EDITIONS MANY NEW TABLES for PRESSURE*
up to 200 LBS. per SQUARE INCH have been added.
"THB MOST VALUABLE WORK on Boilers published in England." Shipping World.
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30 CHARLES GRIFFIN & CO.'S PUBLICATIONS.
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A MANUAL OF
LOCOMOTIVE ENGINEERING;
A Practical Text-Book for the Use of Engine Builders,
Designers and Draughtsmen, Railway
Engineers, and Students.
BY
WILLIAM FRANK PETTIGREW, M.lNST.C.E.
With a Section on American and Continental Engines.
BY ALBERT F. RAYENSHEAR, B.Sc.,
Of Her Majesty's Patent Office.
Contents. Historical Introduction, 1763-1863. Modern Locomotives: Simple.
Modern Locomotives: Compound. Primary Consideration in Locomotive Design.
Cylinders, Steam Chests, and Stuffing Boxes. Pistons, Piston Rods, Crossheads, and
Slide Bars. Connecting and Coupling Rods. Wheels and Axles, Axle Boxes, Hornblocki,
and Bearing Springs. Balancing. Valve Gear. Slide Valves and Valve Gear Details.
Framing, Bogies and Axle Trucks, Radial Axle Boxes. Boilers. Smokebox, Blast Pipe,
Firebox Fittings. Boiler Mountings. Tenders. Railway Brakes. Lubrication. Con-
sumption of Fuel, Evaporation and Engine hfflcUncy. American Locomotives Con-
tinental Locomotives. Repairs, Running, Inspection, and Renewals. Three Appendices.
Index.
"Likely to remain for many years the STANDARD WORK for those wishing to learn
Design." Engineer.
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Railway Official Gazette.
44 We recommend the book as THOROUGHLY PRACTICAL in its character, and MERITING A
PLACE IN ANY COLLECTION of . . . works on Locomotive Engineering." Railway News.
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In Large Svo. Handsome Cloth. With Plates and Illustrations. 16s.
L i cua T RAILWAYS
AT HOME AND ABROAD.
BY WILLIAM HENRY COLE, M.lNST.O.E.,
Late Deputy-Manager, North- Western Railway, India.
Contents. Discussion of the Term " Light Railways." English Railways,
Rates, and Farmers. Light Railways in Belgium, France. Italy, other
European Countries, America and the Colonies, India, Ireland. Road Trans-
port as an alternative. The Light Railways Act, 1896. The Question of
Gauge. Construction and Working. Locomotives and Rolling- Stock. Light
Railways in England, Scotland, and Wales. Appendices and Index.
"Mr. W. H. Cole has brought together ... a LARGE AMOUNT of VALUABLE INFORMA-
TION . . . hitherto practically inaccessible to the ordinary reader." Times.
" Will remain, for some time yet a STANDARD WOKK in everything relating to Light
Railways." b. nginter.
'* The author has extended practical experience that makes the book lucid and metal.
It is EXCEEDINGLY well done." Engineering.
" The whole subject is EXHAUSTIVELY and PRACTICALLY conBidered. The work can be
cordially recommended as INPISPENSABLE to those whose duty it is to become acquainted
with one of the prime necessities of the immediate future." Railway Official Gazette.
" THERE COULD BE NO BETTER BOOK of first reference on its subject. All clasaen of
Engineers will welcome its appearance." Scots man.
LONDON : CHARLES GRIFFIN & CO,, LIMITED, EXETER STREET, STRAND.
ENGINEERING AND MECHANICS. 31
Large Crown 8vo. With numerous Illustrations. 6s.
ENGINE-ROOM PRACTICE ;
A Handbook for Engineers and Officers in the Royal Navy
and Mercantile Marine, Including the Management
of the Main and Auxiliary Engines on
Board Ship.
BY JOHN G. LIVERSIDGE,
Engineer, R.N., A.M.I.C.E., Instructor in Applied Mechanics at the Royal Naval
College, Greenwich.
Contents. General Description of Marine Machinery. The Conditions of Service and
Duties of Engineers of the Royal Navy. Entry and Conditions of Service of Engineers of
the Leading 8.S. Companies. Raising Steam Duties of a Steaming Watch on Engines
and Boilers. Shutting off Steam. Harbour Duties and Watches Adjustments and
Repairs of Engines. Preservation and i.epairs of "Tank" Boilers. The Hull and its
Fittings. Cleaning and Painting Machinery Reciprocating Pumps, Feed Heaters, and
Automatic Feed -Water Regulators. Evaporators. Steam Boats. Electric Light
Machinery. Hydraulic Machinery. Air-Compressing Pumps. Refrigerating Machines.
Machinery of Destroyers. The Management of Water-Tube Boilers. Regulations for
Entry of Assistant Engineers, R.N. Queitions given in Examinations for Promotion of
Engineers, R.N. Regulations respecting Board of Trade Examinations for Engineers, <fec.
" The contents CANNOT FAIL TO BE APPRECIATED." The Steamship.
"This VERY USEFUL BOOK. . . . ILLUSTRATIONS are ot GREAT IMPORTANCE in a work
of this kind, and it is satisfactory to find that SPECIAL ATTENTION has been given in this
respect." Engineers' Gazette.
SECOND EDITION, Revised. With Numerous Illustrations.
Price 7s. 6d.
VALVES AND VALVE-GEARING:
INCLUDING THE CORLISS VALVE AND
TRIP GEARS.
BY
CHARLES HURST, Practical Draughtsman.
" CONCISE explanations illustrated by 115 VERY CLEAR DIAGRAMS and drawings and 4 folding-
plates . . . the book fulfils a VALUABLE function. "A thenasum.
"MR. HUBBT'S VALVES and VALVE-GEARING will prove a very valuable aid, and tend to th
production of Engines of SCIENTIFIC DESIGN and ECONOMICAL WORKING. . . . Will be largely
ought after by Students and Designers." Marine Engineer.
44 USEFUL and THOROUGHLY PRACTICAL. Will undoubtedly be found of GREAT VALUB to
all concerned with the design of Valve-gearing." Mechanical World.
44 Almost EVERY TYPE of VALVE and its gearing is clearly set forth, and illustrated in
uch a way as to be READILY UNDERSTOOD and PRACTICALLY APPLIED by either the Engineer,
Draughtsman, or Student. . . . Should prove both USEFUL and VALUABLE to all Engineer!
eeking for RELIABLE and CLEAR information on the subject. Its moderate price brings it
within the reach of all." Industries and Iron.
44 Mr. HURST'S work is ADMIRABLY suited to the needs of the practical mechanic. . . .
It Is free from any elaborate theoretical discussions, and the explanations of the varioua
types of valve-gear are accompanied by diagrams which render them EASILY UNDERSTOOD."
The Scientific American.
LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAND,
S* GHARLB8 ORIFFIN A CO.'S PUBLICATIONS.
THIRD EDITION. Very fully Ittuttrated. Cloth, 4. fct
STEAM - BOI LERS;
THEIR DEFECTS, MANAGEMENT, AND CONSTRUCTION.
BY R D. MUNRO,
Chief Engineer of the Scottish Boiler Insurance and Engine Inspection Company.
GENERAL CONTENTS. I. EXPLOSIONS caused (i) by Overheating of Plates (i) By
Defective and Overloaded Safety Valves (3) By Corrosion, Internalor External (4) By
Defective Design and Construction (Unsupported Flue Tubes ; Unstrengthened Manholes ;
Defective Staying ; Strength of Rivetted Joints; Factor of Safety) II. CONSTRUCTION OF
VERTICAL BOILERS : Shells Crown Plates and Uptake Tubes Man-Holes, Mud-Holes,
and Fire-Holes Fireboxes Mountings Management Cleaning Table of Bursting
Pressures of Steel Boilers Table of Rivetted Joints Specifications and Drawings of
Lancashire Boiler for Working Pressures (a) 80 Ibs. ; (b) 200 Ibs. per square inch respectively.
" A valuable companion for workmen and engineers engaged about Steam Boilers, ought
to be carefully studied, and ALWAYS AT HAND." Coll. Guardian.
" The book is VERY USEFUL, especially to steam users, artisans and young Engineers."
Engineer.
BY THE SAME AUTHOR.
KITCHEN BOILER EXPLOSIONS: Why
they Occur, and How to Prevent their Occurrence. A Practical Hand-
book based on Actual Experiment. With Diagrams and Coloured Plate,
Price 33.
NYSTROM'S POCKET-BOOK OF MECHANICS
AND ENGINEERING. Revised and Corrected by W. DENNIS MARKS,
Ph.B., C.E. (YALE s.s.s.), Whitney Professor of Dynamical Engineering,
University of Pennsylvania. Pocket Size. Leather, 155, TWENTY-
FIRST EDITION, Revised and greatly enlarged.
Pocket Size, Strongly bound in Leather. 3s. 6d.
THE MINING ENGINEERS' REPORT BOOK
AND DIRECTORS' AND SHAREHOLDERS' GUIDE TO MINING REPORTS.
BY EDWIN R. FIELD, M.lNST.M.M.
With Notes on the Valuation of Mining Property and Tabulating Reports, Usefut
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ENGINEERING AND MECHANICS. 33
FIFTH EDITION. Folio, strongly half-bound, 2i/.
TRAVERSE TABLES:
Computed to Four Places of Decimals for every Minute
of Angle up to 100 of Distance.
For the use of Surveyors and Engineers.
BY
RICHARD LLOYD GURDEN,
Authorised Surveyor for the Goyernments of New South Wales and
Victoria.
*%* Published with the Concurrence 0f ike Surveyors- General for New South
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half an inch, and this BY REFERENCE TO BUT ONE TABLE, in place oi the usual Fifteen
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Engineering Drawing and Design
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THIRD EDITION. In Two Parts, Published Separately.
VOL. I. PRACTICAL GEOMETRY, PLANE, AND SOLID. 3s.
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BY
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A.M.INST.C.B., A.M.INST.MKCH.K.,
Principal of the Battersea Polytechnic Institute, and Head of the Engineering Department
therein ; formerly of the Engineering Departments of the Yorkshire College,
Leeds ; and Dulwich College, London.
With many Illustrations, specially prepared for the Work, and numerous
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11 The first book leads EASILY and NATURALLY towards the second, where the technical pupil
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to brought into contact \
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34 CHARLES GRIFFIN d, CO.'S PUBLICATIONS.
WORKS BY
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A POCKET-BOOK of ELECTRICAL RULES and TABLES,
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ENGINEERING AND MKCHANICS. 35
WORKS BY
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IMPOETANT NEW WORK. READY IMMEDIATELY.
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THE PRINCIPLES AND CONSTRUCTION OF
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BY HENRY DAVEY,
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CONTENTS Early History of Pumping Engines Steam Pumping Engines
Pumps and Pump Valves General Principles of Non-Rotative Pumping
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Engines Pit Work Shaft Sinking Hydraulic Transmission of Power in
Mines Valve Gears of Pumping Engines Water Pressure Pumping Engines
Water Works Engines Pumping Engine Economy and Trials of Pumping
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SECOND EDITIOM, Revised and Enlarged.
In Large 8vo, Handsome cloth, 34&.
HYDRAULIC POWER
AND
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38 CHARLES GRIFFIN & CO.* 8 PUBLICATIONS.
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THE CONSTRUCTION AND MAINTENANCE
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1SNQINEERINQ AND MJSOHANIOS. 39
Fourteenth Edition, Revised. Price 21s.
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A MANUAL OF
MARINE ENGINEERING:
COMPRISING THE DESIGNING, CONSTRUCTION, AND
WORKING OF MARINE MACHINERY.
By A. E. SEAT ON, M. Inst. C.E., M. Inst. Meeh. E.,
M.Inst.N.A.
GKNERAL CONTENTS.
Part I. Principles of Marine
Propulsion.
Part XL-Principles of Steam Valves, &e.
Engineering.
Part III. Details of Marine
Engines: Design and Cal-
culations for Cylinders,
Pistons, Valves, Expansion
Part IV. Propellers.
Part V. Boilers.
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WORKS BY PROF. ROBERT H. SMITH, Assoe.M.I.C.E.,
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ENGINEERING AND MECHANICS. 41
In Large 8vo. Handsome Cloth. 10s. 6d.
CHEMISTRY FOR ENGINEERS.
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SEWAGE DISPOSAL WORKS7
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BY W. SANTO CRIMP, M.lNST.C.K, F.G.S.,
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CALCAREOUS CEMENTS:
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Wi.ii 1m. aoxx&e texra.c.x*ka upon. Gexx*exvt; T
BY GILBERT R. REDGRAVE, Assoc. INST. C.E.
GENERAL CONTENTS. Introduction Historical Review of the Cement
Industry The Early Days of Portland Cement Composition of Portland
Cement PROCESSES OF MANUFACTURE The Washmill and the Backs
Flue and Chamber Drying Processes Calcination of the Cement Mixture
Grinding of the Cement Composition of Mortar and Concrete CEMENT
TESTING CHEMICAL ANALYSIS of Portland Cement, Lime, and Raw
Materials Employment of Slags for Cement Making Scott's Cement,
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ELECTRICAL ENGINEERING. 43
IMPORTANT NEW WORK. READY SHORTLY.
In Large Svo. Handsome Cloth. Profusely Illustrated with Plates^
Diagrams, and Figures.
CENTRAL ELECTRICAL STATIONS:
Their Design, Organisation, and Management.
Including the Generation and Distribution of Electrical
Energy.
BY CHAJS. H. WORDINGHAM,
A.K.C., M.lNST.C.E., M.INST.MECH.E.,
Member of the Council of the Institute of Electrical Engineers, and Electrical
Engineer to the City of Manchester.
CONTENTS.
Introductory. Central Station Work as a Profession. Central Station Supply as an In-
vestment The Establishment of a Central Station Systems of Supply. Choice of Site
Architectural Features. Choice of Plant and General Design. Boilers Systems of
Draught and Waste Heat Economy. Methods of Firing Boilers. Coal Handling, Weighing,
and Storing. Feeding of Boilers. The Transmission of Steam. Generators. Condensing
Appliances. Switching Gear, Instruments, and Connections. Distributing Mains. Drawing-
in Systems. Built-in Systems, Dielectrics. Insulation, Resistance, and Cost. Distributing
Networks Service Mains and Feeders. Testing of Mains. Recording and Laying of
Mains. Meters and Appliances on Consumers' Premises. Standardising and Testing Labor-
atory Secondary Batteries. Street Lighting Cost of Production. Methods of Charging.
Regulations of Consumer's Installations. General Organisations of a Central Station
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ing. The Clerical Department. The Consumer. The Routine and Main Laying. INDEX.
MUNRO ft JAMIESON'S ELECTRICAL POCKET-BOOK.
FOURTEENTH EDITION, Revised and Enlarged.
A POCKET-BOOK
or
ELECTRICAL RULES & TABLES
FOR THE USE OF ELECTRICIANS AND ENGINEERS.
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A TEXT-BOOK OF PHYSICS;
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PROPERTIES OF MATTER; SOUND; HEAT; MAGNETISM
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8C.D., P.E.S., A ND M.A., F.K.8.,
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Volume I., SECOND EDITION, Price 8s. 6d.
S O TJ
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Notes. - Resonance and Forced Oscillations. Analysis of Vibrations. The Transverse
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Membranes. Vibration* maintained by Heat. Sensitive Flames and Jets. Musical
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THE MEAN DENSITY OF THE EARTH;
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iot fail to be of GREAT and OEKBBAL IXTBRBST to the scientific
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NAUTICAL WORKS. 45
6, GRIFFIN'S NAUTICAL SERIES.
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Elementary Seamanship. By D. WILSON-BARKER, Master Mariner*
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"PRECISELY the kind of work required for the New Certificates of competency.
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Latitude and Longitude : How to find them. By W. J. MILLAR,
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" Cannot but prove an acquisition to those studying Navigation." Marine Engineer.
Practical Mechanics : Applied to the requirements of the Sailor.
By THOS. MACKENZIE, Master Mariner, F.R.A.S. 3s. 6d.
" WELL WORTH the money . . . EXCEEDINGLY HELPFUL." Shipping World.
Trigonometry : For the Young Sailor, &c. By RICH. C. BUCK, of the
Thames Nautical Training College, H.M.S. " Worcester." Price 3s. 6d.
"This EMINENTLY PRACTICAL and reliable volume." School master.
Practical Algebra. By RICH. C. BUCK. Companion Volume to the
above, for Sailors and others. Price 3s. 6d.
" It is JUST THE BOOK for the young sailor mindful of progress. Nautical Magazine.
The Legal Duties of Shipmasters. By BENEDICT WM. GINSBURG,
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4s. 6d.
" INVALUABLE to masters. . . . We can fully recommend it," Shipping Gazette.
A Medical and Surgical Help for Shipmasters. Including First
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Hospital, Greenwich. SECOND EDITION, Revised. 6s.
"SOUND, JUDICIOUS, REALLY HELPFUL." 7 he Lancet.
LONDON: CHARLES GRIFFIN & CO., LIMiTED, EXETER STREET, STRAND,
46 OHAMLB8 QXIFPIX * OO.'B PUBLICATIONS.
GRIFFINS NAUTICAL SERIES,
Price 8s. 6d. Post-free.
T 131 IE
British Mercantile Marine.
BY EDWARD BLACKMOUE,
MASTER MARINER; ASSOCIATE OF THE INSTITUTION OF NAVAL ARCHITECTS;
MEMBER OF THE INSTITUTION OF ENGINEERS AND SHIPBUILDERS
IN SCOTLAND; EDITOR OF GRIFFIN'S "NAUTICAL SERIES."
GENERAL CONTENTS. HISTOKICAL : From Early Times to 1486 Progress
tinder Henry VIII. To Death of Mary During Elizabeth's ReignUp to
the Reign of William III. The 18th and 19th Centuries Institution of
Examinations Rise and Progress of Steam Propulsion Development of
Free Trade Shipping Legislation, 1862 to 1875 " Locksley Hall" Case
1884 to 1894
s Mariners
ition: what it
should be Present Means of Education Hints. DISCIPLINE AND DUTY
Postscript The Serious Decrease in the Number of British Seamen, a Matter
demanding the Attention of the Nation.
" INTERESTING and INSTRUCTIVE . . . may be read WITH PROFIT and ENJOYMENT."
&latgou> Herald.
" EVERY BRANCH of the subject is dealt with in a way which shows that the writer
'knows the ropes' familiarly." Scotsman.
"This ADMIRABLE book . . . TEEMS with useful information Should be in the
hands of every Sailor." Western Morning Newt.
WORKS BY RICHARD C. BUCK,
of the Thames Nautical Training College, H.M.S. ' Worcester. 1
1. A Manual of Trigonometry:
With Diagrams, Examples, and Exercises. Post-free 3s. 6d.
%* Mr. Buck's Text-Book has been SPECIALLY PREPARED with a view
to the New Examinations of the Board of Trade, in which Trigonometry
is an obligatory subject.
"This EMINENTLY PRACTICAL and RELIABLE VOLUME." Schoolmaster.
2. A Manual of Algebra.
Designed to meet the Requirements of Sailors and others. Price 8s. 6d.
%* These elementary works on ALGEBRA and TRIGONOMETRY are written specially for
those who will have little opportunity of consulting a Teacher. They are books for "SELJP-
HELP." All but the simplest explanations have, therefore, been avoided, and ANSWERS to
the Exercises are given. Any person may readily, by careful study, become master of their
contents, and thus lay the foundation for a further mathematical course, if desired. It ii
hoped that to the younger Officers of our Mercantile Marine they will be found decidedly
erviceable. The Examples and Exercises are taken from the Examination Papers set for
the Oadets of the "Worcester."
" Clearly arranged, and well got up. ... A first-rate Elementary Algebra.
Nautical Magazine.
%*For complete List of GRIFFIN'S NAUTICAL SERIES, see p. 45.
LONDON : CHARLES GRIFFIN & CO,, LIMITED, EXETER STREET, STRAND.
NA UTICAL WORKS. 47
GRIFFIN'S NAUTICAL SERIES,
SECOND EDITION, Price 5s. Post-free.
JPL JVLAJ&JJl^JLt OF
ELEMENTARY SEAMANSHIP.
BT
D. WILSON-BARKER, MASTER MARINER; F.R.S.E., F.R.G.S.,&o., &o.;
YOUNGER BROTHER OF THE TRINITY HOUSE.
With Frontispiece, Twelve Plates (Two in Colours), and Illustrations
in the Text.
GENERAL CONTENTS. The Building of a Ship; Parts of Hull, Masts,
&c. Ropes, Knots, Splicing, &c. Gear, Lead and Log, &c. Rigging,
Anchors Sailmaking The Sails, &c. Handling of Boats under Sail
Signals and Signalling Rule of the Road Keeping and Relieving Watch
Points of Etiquette Glossary of Sea Terms and Phrases Index.
** The volume contains the NEW RULES OF THE ROAD.
" This ADMIRABLE MANUAL, by OAPT. WILSON-BARKER of the ' Worcester,' seems to u
PERFECTLY DESIGNED, and holds its place excellently in ' GRIFFIN'S NAUTICAL SERIES,' . . .
Although intended for those who are to become Officers of the Merchant Navy, it will b
found useful by ALL YACHTSMEN. " A thenaeum.
u Five shillings will be WKLL SPENT on this little book. CAPT. WILSON-BARKER knowa
from experience what a young man wants at the outset of his career." The Enginur.
Price &?. 6d. Post-free.
NAVIGATION:
JPRACTICAU, A**X> TSiEORETICAJLu
BY DAVID WILSON-BARKER, R.N.R., F.R.S.E., <fec., <fcc. f
AND
WILLIAM ALLINGHAM,
FIRST-CLASS HONOURS, NAVIGATION, SCIENCE AND ART DEPARTMENT.
TOlttb Bumerous JUustratfone anfc ^Examination <aue0tfon$,
GENERAL CONTENTS. Definitions Latitude and Longitude Instruments
of Navigation Correction of Courses Plane Sailing Traverse Sailing Day's
Work Parallel Sailing Middle Latitude Sailing M creator's Chart
Mercator Sailing Current Sailing Position by Bearings Great Circle Sailing
The Tides Questions Appendix : Compass'Ewor Numerous Useful Hints,
&c. Index.
" PRECISELY the kind of work required for the New Certificates of competency in gradei
from Second Mate to extra Master. . . . Candidates will find .1 INVALUABLE." Dundet
Advertiser.
4 A CAPITAL LITTLE BOOK . . . specially adapted to the New Examinations. The
nd
MB. ALLINGHAM, a well-known writer on the Science of Navigation and Nautical Astronomy. "
Shipping World.
V For complete Liat of GRIFFIN'S NAUTICAL SERIES, see p. 45.
LONDON: CHARLES GRIFFIN & CO,, LIMITED, EXETER STREET, STRAND,
4* OHARLSS OKI f FIX <* OO.'B PUBLICATIONS.
GRIFFIN'S NAUTICAL SERIES.
Crown 8vo, with Numerous IllustratioDs. Handsome Cloth. 3s. 6d.
Practical Mechanics:
Applied to the Bequirements of tJae Sailor.
BY THOS. MACKENZIE,
Master Mariner, F.R.A.S.
GENERAL CONTENTS. Resolution and Composition of Forces Work done
by Machines and Living Agents The Mechanical Powers : The Lever j
Derricks as Bent Levers The Wheel and Axle : Windlass ; Ship's Capstan ;
Crab Winch Tackles : the ''Old Man" The Inclined Plane; the Screw
The Centre of Gravity of a Ship and Cargo Relative Strength of Rope :
Steel Wire, Manilla, Hemp, Coir Derricks and Shears Calculation of the
Cross-breaking Strain of ]?ir Spar Centre of Effort of Sails Hydrostatics :
the Diving-bell ; Stability of Floating Bodies ; the Ship's Pump, &c.
" THIS EXCELLENT BOOK . . . contains a LARGE AMOUNT of information."
Naturt.
" WELL WORTH the money . . . will be found EXCEEDINGLY HELPFUL."
Shipping World.
No SHIPS' OFFICERS' BOOKCASE will henceforth be complete without
CAPTAIN MACKENZIE'S * PRACTICAL MECHANICS. ' Notwithstanding my many
years' experience at sea, it has told me how much more there is to acquire."
(Letter to the Publishers from a Master Mariner).
" I must express my thanks to you for the labour and care you hare taken
in 'PRACTICAL MECHANICS/ . . . IT is A LIFE'S EXPERIENCE. . . .
What an amount we frequently see wasted by rigging purchases without reason
wid accidents to spars, &c., &c. ! 'PRACTICAL MECHANICS' WOULD SAVE ALL
THIS." (Letter to the Author from another Master Mariner).
Now READY. Handsome Cloth. Fully Illustrated. 7s. 6d.
MARINE METEOROLOGY,
FOR OFFICERS OF THE MERCHANT NAVY.
BY WILLIAM ALLINGHAM,
Joint Author of "Navigation, Theoretical and Practical."
With numerous Plates, Maps, Diagrams, and Illustrations, and a facsimile
Reproduction of a Page from an actual Meteorological Log-Book.
SUMMARY OF CONTENTS.
INTRODUCTORY. Instruments Used at Sea for Meteorological Purposes. Meteoro-
logical Log-Books. Atmospheric Pressure. Air Temperatures. Sea Temperatures.
Winds. Wind Force Scales. History of the Law of Storms. Hurricanes, Seasons, and
Storm Tracks. Solution of the Cyclone Problem. Ocean Currents. Icebergs. Syn-
chronous Charts. Dew, Mists, Fogs, and Haze. Clouds. Rain, Snow, and Hail.
Mirage, Rainbows, Coronas, Halos, and Meteors. Lightning, Corposants, and Auroras.
QUESTIONS. APPENDIX. INDEX.
\* For Complete List of GRIFFIN'S NAUTICAL SERIES, see p. 45.
LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAND,
NAUTICAL WORKS. 49
GRIFFIN'S NAUTICAL SERIES.
In Crown 8vo. Handsome Cloth. 4s. 6d. Post-free.
THE LEGAL DUTIES OF SHIPMASTERS.
BY
BENEDICT WM. GINSBURG, M.A., LL.D. (CANTAB.),
Of the Inner Temple and Northern Circuit ; Barrister-at-Law.
General Contents. The Qualification for the Position of Shipmaster The Con-
tract with the Shipowner The Master's Duty in respect of the Crew : Engagement ;
Apprentices ; Discipline ; Provisions, Accommodation, and Medical Comforts ; Payment
of Wages and Discharge The Master's Duty in respect of the Passengers The Master'!
Financial Responsibilities The Master's Duty in respect of the Cargo The Master 1 !
Duty in Case of Casualty The ^Master's Duty to certain Public Authorities The
Master's Duty in relation to Pilots, Signals, Flags, and Light Dues The Master's Dutj
upon Arrival at the Port of Discharge Appendices relative to certain Legal Mattera :
Board of Trade Certificates, Dietary Scales, Stowage of Grain Cargoes, Load Line Regula-
tions, Life-saving Appliances, Carriage of Cattle at Sea, fec., &c. Copious Index.
44 No intelligent Master should fail to add this to his list of necessary books. A few line*
of it may SAVE A LAWYER'S FEE, BESIDES ENDLESS WORRY." Liverpool Journal of Commerce.
44 SENSIBLE, plainly written, in CLEAB and NON-TECHNICAL LANGUAGE, and will be found of
MUCH SEBVICB by the Shipmaster. 11 British Trade Review.
Crown 8vo, with Diagrarni. 2s. Post-free.
Latitude and Longitude:
to Find
BY W. J. MILLAR, C.E.,
Late Secretary to the Inst. of Engineers and Shipbuilders in Scotland.
" CONCISELY and CLEARLY WRITTEN . . . cannot but prove an acquisition
to those studying Navigation." Marine Engineer.
" Young Seamen will find it HANDY and USEFUL, SIMPLE and CLEAR." Th*
Engineer. _
FIRST AID AT SEA.
SECOND EDITION, Revised. With Coloured Plates and Numerous Illustra-
tion*, and comprising the latest Regulations Respecting the
Carriage of Medical Stores on Board Ship.
A MEDICAL AND SURGICAL HELP
FOR SHIPMASTERS AND OFFICERS
IN THE MERCHANT NAVY.
BY
WM. JOHNSON SMITH, F.RO.S.,
Principal Medical Officer, Seamen's Hospital, Greenwich.
%* The attention of all interested in our Merchant Na7y IB requested to this exceedingly
useful and valuable work. It is needless to ay that it is the outcome of many year*
PRACTICAL EXPERIENCE amongst Seamen.
" SOUND, JUDICIOUS, REALLT HELPFUL " The Lancet.
\* For Complete List of GRIFFIN'S NAUTICAL SERIES, see p. 46.
LONDON: CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAND.
CHARLES GRIFFIN & CO:S PUBLICATIONS.
GRIFFIN'S NAUTICAL SERIES.
FOUBTH EDITION. Revised throughout, with additional Chapters on
Trim, Buoyancy, and Calculations. Numerous Illustrations.
Handsome Cloth, Crown 8vo. 7s. 6d.
mm SHIP.
BY THOMAS WALTON, NAVAL ARCHITECT.
SPECIALLY ARRANGED TO SUIT THE REQUIREMENTS OF SHIPS* OFFICERS,
SHIPOWNERS, SUPERINTENDENTS, DRAUGHTSMEN, ENGINEERS,
AND OTHERS.
This work explains, in a simple manner, such important
subjects as :
Displacement,
Deadweight,
Tonnage,
Freeboard,
Moments,
Buoyancy,
Strain,
Structure,
Stability,
Rolling,
Ballasting,
Loading,
Shifting Cargoes,
Admission of Water,
Sail Area,
&c., &c.
" The little book will be found EXCEEDINGLY HANDY by most officers and
officials connected with shipping. . . . Mr. Walton's work will obtain
LASTING SUCCESS, because of its unique fitness for those for whom it has been
written." Shipping World.
" An EXCELLENT WORK, full of solid instruction and INVALUABLE to every
officer of the Mercantile Marine who has his profession at heart." Shipping.
" Not one of the 242 pages could well be spared. It will admirably fulfil its
purpose . . . useful to ship owners, ship superintendents, ship draughts-
men, and all interested in shipping." Liverpool Journal of Commerce.
" A mass of VERY USEFUL INFORMATION, accompanied by diagrams and illus-
trations, is given in a compact form." Fair play*
" A large amount of MOST USEFUL INFORMATION is given in the volume.
The book is certain to be of great service to those who desire to be thoroughly
grounded in the subject of which it treats." Steamship.
" We have found no one statement that we could have wished differently
expressed. The matter has, so far as clearness allows, been admirably con-
densed, and is simple enough to be understood by every seaman." Marine
Knyineer.
LONDON: CHARLES GRIFFIN & CO,, LIMITED, EXETER STREET, STRAND.
CHEMISTRY AND TECHNOLOGY. 51
A SHORT MANUAL OF
INORGANIC CHEMISTRY.
BY
A. DUPRE, Ph.D., F.R.S.,
WILSON HAKE, Ph.D., F.I.C., F.C.S.,
Of the Westminster Hospital Medical School
THIRD EDITION, Revised, Enlarged, and brought up-to-date.
" A well-written, clear and accurate Elementary Manual of Inorganic Chemitry. . .
We agree heartily with the system adopted by Drs. Dupri and Hake. WILL MAKE EXPKRI-
MENTAL WORK TRBBLY INTERESTING BECAUSE INTELLIGIBLE." Saturday RevifW.
"There is no question that, given the PERFECT GROUNDING of the Student in his Sciokc*,
the remainder comes afterwards to him in a manner much more simple and easily acquired
The week is AN EXAMPLE OF THE ADVANTAGES OF THE SYSTEMATIC TREATMENT of a
Science over the fragmentary style so generally followed BY A LONG WAY THB BEST qf th
waall Manuals for Student*. A nalyst.
LABORATORY HANDBOOKS BY A. HUMBOLDT SEXTON,
Professor of Metallurgy in the Glasgow and West of Scotland Technical College.
Sexton's (Prof.) Outlines of Quantitative Analysis.
FOR THE USE OF STUDENTS.
With Illustrations. FOURTH EDITION. Crown SYO, Cloth, 3s.
'* A COMPACT LABORATORY GUIDE for beginners was wanted, and the want ha
been WMLL SUPPLIED. ... A good and useful book." Lancet.
Sexton's (Prof.) Outlines of Qualitative Analysis.
FOR THE USE OF STUDENTS.
With Illustrations. THIRD EDITION. Crown 8vo, Cloth, 3s. 6<t
" The work of a thoroughly practical chemist." British Medical Journal.
" Compiled with great care, and will supply a want." Journal of Education.
Sexton's (Prof.) Elementary Metallurgy:
Including the Author's Practical Laboratory Course. With many
Illustrations. [See p. 66 General Catalogue.
SECOND EDITION, Revised. Crown 8vo. Cloth, 6s.
" Just the kind of work for students commencing the study of metallurgy."
Practical Engineer.
LONDON : CHARLES GRIFFIN & CO., LIMITED, EXETER STREET, STRAND.
52 CHARLES GRIFFIN & CO.'S PUBLICATIONS.
SEVENTH EDITION, Price 6.
PRACTICAL SANITATION:
A HAND-BOOK FOR SANITARY INSPECTORS AND OTHERS
INTERESTED IN SANITATION.
By GEORGE REID, M.D., D.P.H.,
follow, Mem. Council, and Examiner, Sanitary Institute of Great Britain,
and Medical Officer to the Staffordshire County Cottncil.
TDdUtb an BppenMj on Sanitary 3Law,
By HERBERT MAN LEY, M.A., M.B., D.P.H.,
Medical Ojficer of Health for the County Borough <?/ West Bronvwich.
GENERAL CONTENTS. Introduction Water Supply: Drinking Water,
Pollution of Water Ventilation and Warming Principles of Sewage
Removal Details of Drainage ; Refuse Removal and Disposal Sanitary
and Insanitary Work and Appliances Details of Plumbers Work House
Construction Infection and Disinfection Food, Inspection of ; Charac-
teristics of Good Meat ; Meat, Milk, Fish, &c., unfit for Human Food-
Appendix : Sanitary Law ; Model Bye-Laws, &c.
"Dr. Reid's very useful Manual . . . ABOUNDS IN PRACTICAL DETAIL.''
British Medical Journal.
"A VERY USEFUL HANDBOOK, with a very useful Appendix. We recommend
it not only to SANITARY INSPECTORS, but to HOUSEHOLDERS and ALL interested
in Sanitary matters." Sanitary Record.
Now READY. Crown 8vo, Handsome Cloth. Fully Illustrated. los. 6d.
FLESH FOODS:
With Methods for their Chemical, Microscopical, and Bacterio-
logical Examination.
A Practical Handbook for Medical Men, Analysts, Inspectors and others.
BY C. AINSWORTH MITCHELL, B.A.(OxoN),
Fellow of the Institute of Chemistry ; Member of Council, Society of Public Analysts.
With Numerous Tables, Illustrations, and a Coloured Plate.
CONTENTS. Structure and Chemical Composition of Muscular Fibre. of
Connective Tissue, and Blood. The Flesh of Different Animals. The Examina-
tion of Flesh. Methods of Examining Animal Fat. The Preservation of Flesh.
Composition and Analysis of Sausages. Proteids of Flesh. Meat Extracts and
Flesh Peptones. The Cooking of Flesh. Poisonous Flesh. The Animal Para-
sites of Flesh. The Bacteriological Examination of Flesh. The Extraction and
Separation of Ptomaines. INDEX.
*** This work is a complete compendium of the CHEMISTRY OF AMIMAL TISSUES. It con-
tains directions for the detection of morbid conditions, pujje&ctive changes, and poisonous
or injurious constituents, together with an account of J^\f bauses and eflfe^ts. Publisher's
Note.
LONDON : CHARLES GRIFFIN & CO., L!ltEV, l ttfoR STREET, STRAND.
JLJFOR1
UNIVERSITY OF CALIFORNIA LIBRARY
BERKELEY
Return to desk from which borrowed.
This book is DUE on the? last date stamped below.
I NOV 13 1947
1 , l3Nov'56 J
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