Seneca, Naturales Quaestiones

THE treatise of which the present volume is a translation
possesses a twofold interest. In the first place, it is prob
ably the last literary work of a man who filled a large
space in the Roman world of his day. After a varied
career as philosopher, barrister, politician, statesman,
courtier, and man of letters, he at last incurred the
implacable enmity of Nero, to whom he had been tutor.
Having in his youth paid some attention to physical
inquiries, he had then been led to prepare and publish
a book on earthquakes. But in subsequent years the
absorbing cares of State probably left him little leisure to
continue these studies, for which, however, he had retained
his taste. Hence, when in his last days he sought in
retirement to devote himself to philosophical pursuits, he
naturally turned to some of the physical problems that
had interested him in earlier life. The earthquake which
on 5th February A.D. 63 had done much damage to the
towns of Campania, revived his youthful enthusiasm for
the investigation of such phenomena, and may possibly
have suggested to him the preparation of another volume
dealing with this and other scientific matter. We know
at least from the book itself that he wrote a part, if not
the whole, of it after that date (221, 2 so), 1 and that he
took pains to collect information about the catastrophe.

1 The numbers within parentheses throughout these Notes refer to the
pages of the Translation.

309



310 PHYSICAL SCIENCE

As he was in the habit of sojourning on the shores of
the Bay of Naples, he probably visited the scene of de
struction himself for the purpose of his book. We learn
from Tacitus that it was immediately after his return
from Campania to his villa near Rome, bringing with him,
we may suppose, his nearly completed manuscript, that
Seneca received the Emperor s order to commit suicide.

In the second place, Seneca s work on Natural
Questions stands out as one of the few treatises on
physical science which have come down to us from anti
quity. It is interesting alike for the quotations it contains
from the works of previous authors, some of which have
not survived, and for the criticisms and opinions which he
himself expresses on the various subjects of which he
treats. It can hardly, however, be regarded as an original
contribution to science. Its author s life had been spent
in other and widely different pursuits, which led him far
away from scientific inquiry. But as a summary of the
general state of knowledge in his day, made by a man of
strong intellect, who had been trained in the legal and
philosophical schools of the time, and had read widely and
reflected much on these matters, the book may be taken to
afford a fair presentation of the manner in which a number
of questions in astronomy, meteorology, and physical geo
graphy were regarded by thoughtful minds in the first
century of our era.

In judging of the intrinsic merit of such a work as the
present, the modern reader finds a difficulty in realising
from the broad platform of natural knowledge which, after
the labours of the intervening centuries, has now been
laid, how exceedingly narrow was the circle of ascertained
fact available to the student two thousand years ago. The
spirit of scientific observation and experiment had not then
been developed, yet the familiar phenomena of every
day life pressed, as they still do, for explanation. Man s
knowledge of nature was then too limited to furnish a
basis for distinguishing what was fact from what was mere
guesswork. In the infancy of our race, as in the childhood
of the individual, the tendency of the human mind is to



NOTES 311

perceive resemblances rather than differences. Analogies
are readily observed and, in default of knowledge of
the facts involved, are mistaken for identical sequences
of cause and effect Throughout the interpretations of
natural phenomena given by the philosophers of antiquity,
it is remarkable to what a large extent the meaning of
one appearance is explained by comparing it with another
to which in reality it may bear no resemblance. Seneca s
volume abounds in examples of this use of analogy.

The authority of great names exercised a wonderful
fascination on the minds of the early investigators of
nature. Generation after generation of writers were led
to accept with little or no modification the dicta of
eminent philosophers who had preceded them. An ob
server might sometimes recognise the erroneousness of the
opinion of a predecessor, and yet lack the means of
detecting the falsity of his own, which nevertheless he
propounded with full assurance of its truth. In such
circumstances criticism had no secure foundation, while
credulity, rampant in the world outside, could hardly fail
to show itself in philosophic circles. Even the most
cautious and truth-seeking inquirer might easily and almost
inevitably be led to accept statements which did not seem
to him unreasonable, and which no previous experience of
his own or others warranted him to disbelieve or even to
suspect.

It behoves us, therefore, to be on our guard lest, from
our much higher standard of knowledge, we may be
tempted to look with amused contempt on the puerile
conceptions of nature to be met with in the writings of
the ancients the grave assertion of absurdities as actual
facts, the inept analogies, the confident explanations which
are no explanations at all, and the complete absence of
any attempt to test by examination or experiment the
validity of statements which with but little trouble could
have been disproved.

These evidences of the exceedingly imperfect knowledge
of his time are fully illustrated in Seneca s chapters. He
quotes some two dozen of previous writers who had dealt



312 PHYSICAL SCIENCE

with the same or cognate subjects. It is needless to say
that they were Greeks, no place having yet been found
in Latin literature for treatises on Science. The author
most frequently cited by him is Aristotle, whose Meteoro-
logica he had evidently studied with care. He gives
frequent quotations from that work, but even where he
does not specifically quote, his views generally accord
with those of the great philosopher and naturalist. 1 Almost
the only quotations from the works of his own countrymen
are verses from some of the poets, especially from Virgil
and Ovid. It is remarkable that he makes only one
quotation from Lucretius, although he would have found
in that poet s noble work many passages more apposite
to his subject than those which he has taken from the
Aeneid, the Georgics, and the Metamorphoses. We may
suppose that these works were favourites with him, and
that he knew much of them by heart, but that he was less
familiar with the De Rermn Natura.

It is manifest from the present volume that its author,
like Lucretius before him, had a lofty conception of the
dignity and moral influence of the study of nature. This
pursuit seemed to him to raise us above the sordid things
of life and to withdraw the mind from the body a
dissociation so eminently beneficial to our higher aspira
tions. He believed that in the study of the hidden
phenomena of the universe a mental alacrity is developed
which will be found to be not without practical utility in
the conduct of affairs that lie nearer the surface (113).

With this clear recognition of the importance of his
theme he resolved in his old age to enter upon a task
which other less worthy pursuits had hindered him from
pursuing. He would now attempt to survey the universe,
unravel its secrets, and give the results of his studies to
the world (109). It was not, however, his aim to compose
a systematic treatise on Natural Philosophy, but rather
to take up some special subjects and deal with them in

1 Seneca s indebtedness to Aristotle is emphatically expressed by Barthelemy
Saint-Hilaire in the Dissertation prefixed to his translation of the Meteorc-
logica (Mttorologic d"* Aristote, 1863, pp. Ixix-lxx).



NOTES 313

the light of what had already been written upon them,
and of what his own reflections suggested. His under
taking assumed the form of a series of epistolary essays
addressed to his friend Lucilius Junior, procurator of
Sicily. The literary shape thus selected allowed the use
of an unconstrained, almost colloquial, style which would
not have been suitable to a more ambitious work.

Had Seneca designed to prepare a formal or methodical
treatise, he would doubtless have planned it to include
the three sections which he regarded as comprising every
inquiry that can arise as to the nature and constitution
of the Universe (Untversum) celestial, atmospheric, and
terrestrial (Caelestia, Sublimia^ Terrena, 51). The world
(Mundus) in his view comprehends all things that come
or can come within our cognisance (54). Instead of
entering upon a full discussion of any one of his three
sections, he selected from them a few topics which had
probably more particularly engaged his attention. Most
of these belong to the second or atmospheric division of
his scheme of arrangement, to which he devotes six of
his seven books, the remaining one being given to the
discussion of some celestial phenomena. Certain subjects
which we should naturally range in the terrestrial series,
such as the source and flow of rivers and the nature and
origin of earthquakes, he explicitly includes among his
atmospheric phenomena (5 i).

It appears to be probable that Seneca had neither
finished nor revised his manuscript at the time of his
death. Parts of the work are obviously incomplete, though
some of these gaps may be due to defects of transcription
or to the subsequent loss of parts of the text. The
obscurities of language, which are not infrequent, may like
wise have partly arisen from lack of the author s revision
of his original copy. His discussion of the problem of
the rise of the Nile suddenly breaks off in such an abrupt
manner as to suggest the loss of a portion of the original
volume. One of the most important omissions is the
absence of any account of the phenomena of volcanoes.
The author does indeed refer in several places to this



3 i4 PHYSICAL SCIENCE

subject, but with Aetna before him, of which so many
Greek and Latin poets had sung, and which had so often
been referred to in the writings of the philosophers, he
could hardly have meant to offer no commentary on so
notable a feature in the geography and history of his own
country. We know indeed that he was keenly interested
in this mountain, and that he wrote to Lucilius to ascend
the volcano and send him particulars about it. In the
letter conveying this request he alludes to some of the
Roman poets who had sung of its wonders, and urges that
a description of Aetna should form part of a poem on
which his correspondent appears to have been then en
gaged. 1 Another important subject in physical geography
finds no place in Seneca s volume the Sea. Of the outer
ocean it was not to be expected that he could have had
much to say, but we can hardly suppose that he would have
considered his essay complete without some discussion of
the various phenomena presented by the Mediterranean Sea.
A century before Seneca s prime, the immortal De
Rermn Natura of Lucretius had appeared at Rome, wherein
the origin and constitution of the world were sung with
the intense earnestness, brilliant imagination, and resound
ing cadence of a great poet and with the grasp and
penetration of a great philosopher. In this splendid work
some of the problems discussed by Seneca were considered,
and explanations were given of them with the usual un-
doubting confidence of olden time. In literary quality the
two writers stand far apart, yet it is not uninteresting to
compare their respective views of nature. The vivid and
often majestic diction of the one is not more diverse from
the somewhat familiar and conversational tone of the other
than are their respective creeds. Lucretius was a con
vinced and enthusiastic Epicurean, and in accordance with
the teachings of his master denied the existence of any
divine co-operation in the plan and government of the
Universe,

nequaquam nobis divinitus esse paratam

naturam rerum, 2

1 Seneca, Epist. Ixxix. 2 De Rerum Natura, v. 198.



NOTES 315

although no writer either of ancient or modern time
has had a more overpowering sense of the beauty,
majesty, and order of this world. It was his earnest
purpose to show men how, by a contemplation of the
face and ordered scheme of nature, they could free them
selves from the bond of religious superstition and the fear
of death. 1

Seneca, on the other hand, held the Stoic belief in an
all-wise and omnipotent Creator. In an eloquent exordium
to his volume, and in a peroration near its end, he affirms
his conviction that this Divine Being is all in all, at once
within and without his works ; He has clothed himself
with creation, but is hidden from our eyes and can be
perceived only by thought (3, 7, 305). Our philosopher
could not conceive of anything more beautiful, more
orderly, and more consistent everywhere in plan than the
world around us. That such a world should have resulted
from the tumult of chaos, by the mere chance collocation
of atoms, appeared to him the madness of vulgar error.
Yet it was only too true, though it might be thought
hardly credible, that even philosophers had been tainted
with this pernicious doctrine. Hence it would be in the
author s judgment a profitable task to inquire into the
truth concerning these matters. To explore this world,
he remarks, is far more than enough for a single lifetime.
Whether what we may be led to believe regarding it shall be
true must be decided by those who may attain the knowledge
of the truth ; we can but examine and conjecture, with no
certain assurance of discovery, yet not without hope (304).
It behoves us to be ever watchful against forming con
clusions rashly, disrespectfully, or ignorantly, and of being
knowingly untrue. In this quest after knowledge, while
much may be found out which will be of practical useful-

1 rursus in antiquas referuntur religiones
et dominos acres adsciscunt, omnia posse
quos miseri credunt, ignari quid queat esse,
quid nequeat, finita potestas denique cuique
quanam sit ratione atque alte terminus haerens. Op. cit. v. 86.

hunc igitur terrorem animi tenebrasque necessest

non radii solis neque lucida tela diei

discutiant, sed naturae species ratioque. i. 146.



3 i6 PHYSICAL SCIENCE

ness, we are encouraged to advance, not by any hope of
gain, but by the wonder with which the inquiry fills the
soul. To obtain a knowledge of Nature is the highest
reward to which the mind of man can aspire (230, 304).
Seneca s practical conclusion was thus much the same as
that of Lucretius. He does not, however, attempt in this
volume to enforce it with the solemn earnestness shown
by the poet, though he loses no opportunity of inveighing
against the follies and vices of his time. In discussing
natural phenomena his first desire is to explain them, and
in so doing to animadvert on the explanations of previous
writers, with perhaps a not unnatural wish to show his
own ability as a critic and expositor.

It was in due accordance with the principles of his
school, as well as with his own natural temperament, that
Seneca should continually be led to draw ethical lessons
from the physical phenomena which he discussed. The
interpolation of some of these reflections may occasionally
seem to a modern reader rather irrelevant and far-fetched,
but there can be no question as to the spirit of reverence
with which he approached his subject. Like other philo
sophers who had preceded him, he maintained this spirit,
while at the same time he had discarded the crowded and
confused polytheism of the prevalent mythology. But he
here keeps this antagonism in due restraint, only occasion
ally expressing his dissent from the popular creed. He
would not admit that even the old philosophers could
have been so foolish as to credit the gods with some of
the acts which had been popularly attributed to them.
He refused to believe that the guardian and ruler of the
Universe hurled thunderbolts with his own hand. Still
less could he suppose that the gods had lighter bolts with
which they amused themselves in play. His expression
(fulminibus lusoriis, 91) recalls the bitter irony of Lucretius
and the sarcasm of his question whether, when the gods
aim at lonely places or at the sea, they are only at
practice to strengthen their arms. 1 But Seneca held with
Lucretius that in the contemplation of nature we obtain

1 an turn bracchia consuescvmt firmantque lacertos? vi. 397.



NOTES 317

the courage and elevation of mind which fit us for the
trials of life and the coming of death (113).

In the treatment of scientific problems Seneca dis
plays the same unhesitating assurance of the truth of his
opinions, which was characteristic of the philosophers of
antiquity. These writers had hardly a glimmering concep
tion of nature s infinite complexity, of the extreme diversity
and intricacy of natural processes, of the unbroken and
endlessly ramifying relations of cause and effect, of the
long and patient investigation by which alone these
relations could be unravelled, and of the caution and
diffidence with which conclusions regarding them should
at least for a time be formulated. Seneca frequently
passes caustic criticisms on the views expressed by his
predecessors. He styles the philosophers, as a body, " a
credulous folk." Some of them he even goes so far as to
accuse of perpetrating deliberate falsehoods (276, 286,
289). Nor does he hesitate to banter his brethren of the
Stoic School, whose " absurdities," as he calls them, he
cannot refrain from quoting.

Yet when his own opinions are examined in the light
of the present day, they are found to be in many cases no
nearer the truth than those which he rejected with con
tempt. It is, indeed, sometimes difficult to realise the
mental position of a man who could adopt and propound
them. In many cases he accounts for a phenomenon by
the analogy of another to which it has no real affinity,
as where he explains halos by the circular undulations
produced on a surface of water into which a stone is
thrown (13). He sometimes suggests an experiment to
prove the truth of his assertion, but if he had made the
experiment he would have found how completely it failed
to support him, as, for instance, when he states that a
large pond of water reflects only one image of the sun,
but that, if it is divided into several smaller ponds by the
insertion of partitions, it will show as many images as
there are divisions (18). Striking also and numerous
are the examples of his credulous acceptance of statements
which, had it occurred to him to test them by actual



3 i8 PHYSICAL SCIENCE

examination, he could easily have found to be erroneous.
He affirms, for instance, more than once, that while
lightning melts metals, it freezes wine, and he gravely
alleges that when the wine is thawed and imbibed, it
either kills or drives mad those who partake of it (79, 97).
He asserts that the waters of certain rivers have the
power of dyeing whole flocks of sheep, black fleeces being
changed into white, and white into black (137), that some
waters are so dense that even the heaviest objects will
not sink in them (138); that the heat of the sun in the
Nile valley is so great as to melt silver and the joints of
statues (173). When he proceeds to explain the reason
of such abnormalities he expresses no hesitation, but
delivers his opinion with the assurance of a professor
who has obtained the experimental demonstration in
his laboratory.

It is remarkable that although some progress had been
made in astronomy, especially by Greek philosophers,
before the beginning of the Christian era, the conclusions
arrived at by these observers regarding the relations of
the earth to the other heavenly bodies met with but little
acceptance for many centuries, even among reflecting
minds. Lucretius, for example, still believed the earth
to be the centre of the Universe to which all the heavier
materials had converged, while the fire-laden ether escaped
to the outer boundaries of space, sun, moon, and stars
occupying an intermediate place. He did not think that
the sun can be much larger than it looks to be to our
senses, nor was he quite sure whether it is the same sun
which, passing under the earth, reappears in the morning,
or if at the close of each day the sun is extinguished and a
new collection of fires makes a fresh sun in the morning.
He was quite aware of the different views of Chaldaean
sages and astronomers, but in such questions he could see
no reason why one theory should be better than another. 1

Seneca, however, had, on the whole, a more advanced
appreciation of the relations of the earth to the heavenly
bodies. He believed the sun to be larger than our globe,

1 De Rer. Nat. v. 564, 650, 680, 727.



NOTES 319

and that a thousand stars might be put together without
equalling his mass (284, 288). He thought the heavens
to be so vast as to afford space for the swiftest of the
planets to rush along with uninterrupted speed during
full thirty years (7). He showed his enlightened outlook
upon astronomical possibilities when he surmised that
comets may have orbits that carry them far beyond the
Zodiac, and when he conjectured that other planets than
those then known remained to be discovered (296-299).
And yet, sharing these more enlarged conceptions, he
clung with curious pertinacity to some of the old childish
faith which was natural in the infancy of mankind.
He knew that some philosophers held that it is the
earth which revolves and not the heavens, and though
he does not deliberately reject this opinion, it is evident
that he still held that the heavens circle round the
earth. 1 Again and again he expresses his conviction
that the force which sustains the energy of the sun
and the stars consists of the exhalations that arise from
the surface of the earth. These exhalations, he says,
are the pasturage of the heavenly bodies, the breath of the
world. It would be impossible, he asserts, for the earth
to furnish so ample a store of nourishment to bodies
larger than itself unless it were full of breath which is
passing off from every part of its surface both by day and
night. To the obvious objection that the supply of this
energy would soon become exhausted, he has the reply
that this exhaustion would certainly take place were it
not that the elements are in a condition of continual
transformation, issuing in one form, passing into each
other, and returning to their original positions, thence to
begin their cycle anew (55, 198, 244-5). In this uni
versal transmutation water passes into air, air into water ;
air likewise is changed into fire, fire into air, while earth
is formed from water, and water from earth (120).

In his general conception of the universe, Seneca, as a
Stoic philosopher, recognised a principle of evolution.
He believed that the world embraces in its constitution

1 Seepostea, Notes on Book VII.



3 2o PHYSICAL SCIENCE

everything that it is destined to experience from its
beginning to its end. As a human embryo contains the
germ of the future man, so at the first creation of the
universe, sun and moon, the changes of the stars, and the
birth of living things were all embraced. And there were
likewise included the forces whereby the earth is affected,
and which will ultimately lead to the final destruction of
the globe (15 i). 1

With regard to the earth itself, whether it is to be
regarded as a soul or as an organised body, Seneca
announced his conviction that it has been constructed
much after the plan of our human bodies. As in these
bodies, veins and arteries are provided for the reception
of blood and breath, so in the earth there are passages,
some for the transport of water, others for the flow of
air (126). He was sure, also, that everything on the
surface of the earth has its counterpart beneath caves,
mountains, lakes, and rivers.

1 Lucretius, too, had his views on evolution, which are well expressed in
four lines of verse :

mutat enim mundi naturam totius aetas,
ex alioque alius status excipere omnia debet,
nee manet ulla sui similis res : omnia migrant,
omnia commutat natura et vertere cogit.

-De Rer. Nat. v. 828.



BOOK I

IN this part of his Essay the author has grouped together a
variety of phenomena, some of which are meteorological (in the
modern sense of that word), and belong therefore to his class of
Sublimia, while others are astronomical, and would be properly
placed among his Caelestia. They all have reference to light in
some form, and doubtless for that reason were considered as a
series. Seneca, largely swayed by the opinions expressed in
Aristotle s Meteorologica, agrees with that philosopher in the
belief that the earth gives forth various kinds of exhalations,
among which some contain the seeds of fire. He thought that
high up in the air, among dry and hot elements, these fires may
be kindled by the sun s rays, and further, that when the atmo
sphere becomes violently disturbed its friction may give rise to
fires (9, 10, 39).

With these ideas, which he held as established truths, it is
easy to understand that he should have regarded as extremely
foolish the notion that any of the lights which move rapidly
across the sky are of celestial origin. Had such been their
source, he felt sure that by this time there would have been none
left in the firmament ; yet although no night passes when some of
them may not be seen, each star in the sky is found to maintain
its place and its size. Hence he confidently concluded that the
meteors, which are seen at night, and sometimes even by day,
have their birth far below the stars, and are soon extinguished in
their course because they have no solid and abiding resting-place.
Single aerolites and even showers of stones had been recorded
in Roman literature as having fallen from heaven, but it had not
yet occurred to any observer to connect them with the shooting
stars which gleam across the nocturnal sky, and are now recog
nised to be due to meteorites of different sizes, entering our
atmosphere with planetary velocity, there breaking up with
varying luminosity, and remaining visible for shorter or longer
intervals of time.

The author appears to have regarded as akin to these meteors

321 Y



322 PHYSICAL SCIENCE

the star-like balls of light, which in stormy weather are sometimes
seen on the masts of vessels at sea, and which before his time
had been observed on the points of the spears of an army in the
field. This luminous appearance, regarded by the Romans as a
sign of the friendly presence of Castor and Pollux, is entirely
atmospheric, and has no connection with shooting stars. It is
now known as St. Elmo s Fire, and has been shown to be a gentle
continuous electric discharge from the earth towards a cloud.

Seneca next describes in some detail a series of optical appear
ances connected with the sun and moon. Until the laws of the
reflection and refraction of light had been discovered, it was
obviously impossible to account for these phenomena. There is,
therefore, much interest in following the lines of thought by which
the old philosophers attempted to explain them. Seneca clearly
perceived that the halos and coronae seen round the sun and
moon in certain states of the atmosphere do not belong to these
luminaries, but to our own air, and may furnish indications of
coming weather. He remarks shrewdly enough that appearances
akin to those seen in the sky may sometimes be observed in the
thick moist air of a bathroom. But when he confidently proceeds
to explain the meteorological phenomena he betakes himself to
analogy, as he is so fond of doing. He remarks that when a
stone is thrown into a pond a succession of circles is produced
on the surface of the water, which continually widen from the
point of impact until they lessen and disappear. In like manner
he believes that when the light of the sun or moon strikes the
cloudy air it produces a similar effect, for as every kind of light
is round in shape, the air is thus driven into a circular form.
His love of analogy generally, as in this instance, leads him far
away from the truth, and prevents him from seeing the palpable
flaws in his reasoning. But the apparent similarity of appearances,
which are in reality entirely dissimilar, contents him with his
explanations.

His discussion of the rainbow (16-33) i one f tne most
detailed and vivacious in the whole volume. It takes the form
of a sustained argument, in which the author cites various authori
ties, and replies to objections brought by a supposed opponent
to his thesis, which is that the rainbow is unquestionably an image
of the sun received in a very moist cloud which has the shape
of a round concave mirror (20, 27). He quotes with apparent
approbation the opinion that in a shower of rain each falling drop
is a mirror reflecting an image of the sun, and that when an
observer stands directly between the sun and the shower he sees
the reflections of the countless drops blended into one continuous
semicircle. But as the discussion proceeds the writer denies that the



NOTES 323

cloud consists of separate rain-drops, and he maintains that even
if it did they would not unite to give one unbroken image. In
proof of his contention he urges the fallacious assertion that if a
number of mirrors are joined together and a man is placed before
them, each gives its own reflection, and thus a single man becomes
multiplied into a crowd. If he had ever tried the experiment or
had visited the shop of a mender of mirrors, he would have seen
that the separate pieces, if strictly arranged on the same plane,
reflect a single image. His imaginary antagonist asks for an
explanation of the rainbow-like colours displayed by the spray
from a burst water-pipe, or the splash from an oar, which are, of
course, cases strictly parallel to the falling shower of rain (24).
The resemblance is at once granted, but is explained away on
the ground that the drops fall so quickly that they cannot form
reflections of the sun, and that to produce such reflections the
medium must be at rest. The objector once more strikes in
with a reference to the rainbow colours to be seen in a glass rod
which is placed obliquely in the path of the sun s rays (30).
These prismatic tints, as has long been known, are due to the same
decomposition of white light, as in the rainbow. But Seneca
claims the illustration as furnishing additional arguments in his
favour. He maintains that no colour is really produced in the
rod, but only a false appearance of colour, his idea being appar
ently that unless the colour is inherent in an object apart from
direct sunlight, it is only apparent and not real. The glass, he
says, tries to reproduce the sun s image, but fails because of its
unsymmetrical form, the reflections being crowded together and
confused into the appearance of a single band of colour. In
regard to the falling drops of rain in a shower he contends that
they receive the colour but not the image of the sun, and he is
led away by the false analogy of the varying tints of a peacock s
neck as the bird tosses its head (25). At one part of the dis
cussion he affirms that the colours of the rainbow come partly
from the sun and partly from the moist cloud (21). Further on,
however, he agrees that they proceed from the sun, but are only
apparent, for if another cloud comes across the face of the
luminary they at once vanish (29). The greater diameter of the
rainbow compared with that of the sun as seen by us he accounts
for by the analogy of a concave mirror, which greatly enlarges
the objects reflected from it. At the conclusion of the discussion
he repeats his belief that the rainbow and the corona or halo
have no definite material inherent in them, but are like a mirror
which reveals only a deception, the mere phantoms and empty
imitations of real bodies, which certainly do not exist in the
mirror, and therefore cannot come out of it (41).



324 PHYSICAL SCIENCE



In Chapters XVI. and XVII. the author indulges in one of
his favourite moralising episodes, suggested by the topics he has
been discussing in the previous pages. He takes the existence
of reflecting surfaces as his text, and from the calm surface of
still water passes on to artificial mirrors, contrasting the manners
and morals of early mankind, who had only pools and lakes in
which to see their faces, with the luxury and vice of later ages,
when the use of metals led to the invention of metallic mirrors.
In this retrospect, however, he places the discovery of the use
of iron before that of the other metals. The priority of bronze
and the reason for it are accurately stated by Lucretius :

et prior aeris erat quam ferri cognitus usus,
quo facilis magis est natura et copia maior. 1



BOOK II

In this division of his work the author discusses various aspects
of the atmosphere and offers an explanation of the phenomena
which he describes. He distinguishes between the very bright
ether on high, and the moist, denser atmosphere which underlies
it, but thinks that they must pass insensibly into each other (66).
The atmosphere he regards as a continuous non-composite body,
capable of great range in tension, and forming the vehicle through
which the exhalations from the earth pass outwards to the sky.
It does not everywhere possess the same qualities. In its lower
parts next the earth it is dense and misty, owing to the terrestrial
exhalations, and is there warmed by the earth s breath, by the
reflection of the sun s rays from the ground, and from the fires,
artificial and subterranean, as well as from the warmth communi
cated by living animals and plants, for life cannot exist without
heat. The highest portions of the atmosphere are exceedingly
dry, hot, and attenuated, owing to their nearness to the eternal
fires and the heat of the heavenly bodies. The middle parts, on
the contrary, are intermediate in character, but colder than what
lies above and below them (60, 61). It is the lower portions
that are subject to the greatest changes, for they receive the
earthly elements which involve such constant turmoil. The in
stability of the air arises also in part from the motions of the
earth and from those of the sun, moon, and stars, to which cold,
rain, and other atmospheric disturbances are due (56, 61).

Seneca, in passing on to discuss the nature and origin of

1 De Rer. Nat. v. 1287.



NOTES 325



thunder and lightning, divides the phenomena into three kinds
lightning -flashes, thunderbolts, and thunderings (62). After
citing and commenting on the opinions of various philosophers
he proceeds to give his own views regarding these appearances.
The lightning flash (Julguratw) he looks upon as fire widely
spread out, the thunderbolt (fulmen) as fire condensed and
hurled with violence (66). The difference between the two is in
force rather than character ; a flash is a bolt without strength
enough to reach the earth, while a thunderbolt is lightning in its
most intense form (69). With regard to the origin of the fire
he points out that fire may be artificially produced in two ways :
either by percussion, as when stones are struck ; or by friction,
as when two bits of wood are rubbed against each other. He
thinks that probably in both of these ways clouds may emit fire,
and that in the violence of storms a source of energy is supplied
whereby the warm or smoky exhalations from the earth may be
kindled and fall with a fierce glow to the earth (70, 101). These
exhalations contain dry and moist bodies, to which heavier ele
ments may be added. A combination of such materials will
form a thicker and more solid cloud than one of pure air, and
such a cloud may burst with a loud report (78). There can be
no peal of thunder unless the hollow clouds are broken up with
great violence (76). The characteristic path of the thunderbolt
is determined by the oblique current of air in which, while the
natural tendency of the fire is upward, the violence of its dis
charge presses it downwards and compels it to take up a zig-zag
course. The peculiar ozone odour noticed during thunderstorms,
and long popularly known as the smell of sulphur, is alluded
to by Seneca (69, 97) and by Lucretius. 1

The discussion of these subjects leads on to a disquisition on
the portents that may be drawn from different kinds of thunder
and various forms of lightning. Seneca infers from the effects
produced by it that lightning possesses an inherent divine power.
Among these effects he enumerates some in which he seems to
have thoroughly believed, such, for instance, as the smashing of a
wine jar already quoted, and the freezing of the wine for the
space of three days thereafter. He is thus disposed to attach
credit to the opinion that future events are foretold by both

1 Similar views on thunder and lightning are expressed in the De Rerum
Natura :

semina quod nubes ipsas permulta necessust
ignis habere. vi. 206.

post ubi conminuit vis eius et impetus acer,

turn perterricrepo sonitu dat scissa fragorem. Ibid. 128.

. . . notaeque gravis halantis sulpuris auras. Ibid. 221.



326 PHYSICAL SCIENCE

lightning and thunder. Yet he cannot change his Stoic faith
that fate, that is, the necessity for the happening of all things and
all actions, can be set aside by no force, can be altered by no
portents, nor averted by any prayer or sacrifice. Though he
admits that vows and supplications may be useful to the wor
shippers, he knows that even these also are included in the
decrees of fate.

These reflections lead the philosopher to a characteristic
peroration on the moral lessons to be derived from the subjects
he has been discussing. From the dangers incident to thunder
storms he passes to the enforcement of the Stoic doctrine that
death must be despised, and everything which leads to death will
then cease to have any terror.



BOOK III

The subjects comprised in this section of the treatise have
reference chiefly to the springs and rivers which appear on the
surface of the earth or flow underneath it. The Book begins
with a preface, which may have been originally designed to stand
at the beginning of the volume. It bears internal evidence of
having probably been written at the time of the author s resolve
to take up the discussion of physical problems, as it speaks of old
age pressing upon him and leaving him but a short while to cover
the immense field which he wished to survey. The years lost
among vain pursuits must be repaired by diligence in the task
now undertaken ; night must be added to day, and every social
or business care which can possibly be set aside must be aban
doned. The contemplation of the work before him then leads
the philosopher into his moralising mood, wherein he inquires
what should be the principal object of human life, concluding
with the reflection that the best thing a man can set before him
self, among the ups and downs of this world, is courage to accept
them calmly and to be ready to meet death boldly whenever
summoned. To the acquisition of such a courage a contempla
tion of nature will greatly conduce.

Seneca begins his discussion of the various forms of water by
grouping them into two chief classes, standing in collected sheets,
as in lakes, or running in channels, as rivers above ground and
springs underneath. After a brief enumeration of various qualities
of water, he inquires whence the vast volume of water comes that
is carried down by rivers to the sea, and how it happens that
neither is the earth sensible of this daily loss, nor does the ocean



NOTES 327

show any perceptible gain. He merely notices the opinion which
some philosophers had expressed that the sea does not get larger
because it restores to the earth as much water as it receives,
allowing its own saline water to sink through endless subterranean
winding passages wherein it is purged of its saltness and rises on
the land as pure fresh water. 1 Another view, that most of the water
supplied by rain eventually finds its way into the rivers, is approxi
mately that at which modern research has arrived, but it meets
with our philosopher s strong opposition. His first objection is
derived from his own observation. He tells us that, as a diligent
digger among his vines, he can confidently affirm that even the
heaviest rain does not penetrate to a depth of more than ten feet
from the surface. What is not absorbed by the upper crust of
the ground runs at once into river channels, and thence into the
sea. He next asks how rain, which immediately flows off the
surface of naked rocks, can possibly be the source of the springs
and rivers that issue from bare crags, or how springs that appear
on the very summit of mountains can be due to rain. Though
he could not but be aware of the close connection everywhere
observable between evaporation, rainfall, and the volume of
springs and rivers, he does not seem to have reflected on its
meaning how in seasons of drought the surface waters fail first,
how by degrees the springs begin to lessen and even to cease,
how the rivers dwindle until in many cases their beds become
almost or quite dry, and yet how, when welcome rains set in, the
springs and rivers gradually resume the bulk they had before the
dry weather impoverished them. He had made no study of the
way in which rain percolates through the soil, subsoil, and
rocks underneath, though there are places, such as his vineyard
may have been, where, from some impervious material, only a
feeble or inappreciable flow of moisture descends beyond a few
feet from the surface. Nor was he aware of the innumerable
lines of joint by which the most solid rocks are traversed, and
which serve as passages for the descent and ascent of water.
Had he climbed many mountains, he would have failed to find a
spring on the summit of any one of them, unless there had been
a sufficient area of higher ground at hand to serve for the supply
of the water.

The origin of underground water is regarded by Seneca as

1 This is the view expressed by Lucretius :

. . . ut in mare de terris venit umor aquai,
in terras itidem manare ex aequore salso ;
percolatur enim virus, retroque remanat
materies umoris et ad caput amnibus omnis
confluit, inde super terras redit agmine dulci.

De Rer, Nat, vi. 633.



328 PHYSICAL SCIENCE

due to three causes. The earth itself contains moisture which it
forces out at the surface ; it includes also air which in the dark
ness of the subterranean wintry cold is condensed into moisture
by the principle of interchangeability, whereby one element passes
into another, the earth in its interior resolves itself into moisture.
If it be urged that the rivers are too vast to draw their supplies
from these sources, the ready answer comes that the internal
reservoir is quite spacious enough for the purpose, and that it
might as well be matter of surprise that, with all the winds that
constantly blow, the supply of air does not fail, or that a single
wave of the sea should be left to follow so many breakers. If
the questioner, still unsatisfied, should demand to know how water
is produced, he is met with the query how air is produced on earth.
There are in nature four elements, and he is rtot entitled to ask
where one of them comes from. Each is a fourth part of nature,
and it is obvious that what has an element as its source cannot
fail. Hence the philosopher in pronouncing water to be an
element has given it enough, and more than enough, of strength.
In short, rain may give rise to a torrent, but not a river flowing
steadily between its banks. Heavy rains will swell such a river,
but cannot produce it.

Having, as he believed, cleared the ground in this way, Seneca
proceeds to consider the distribution of water within the earth.
He opines that as in our body, so in the earth, there are channels
by which both air and liquids flow. He states his conviction
that the earth contains not only veins of water, but also large
streams, and in a later part of the volume he speaks of both
underground rivers, huge lakes, and a hidden sea from which
rivers at the surface are supplied (154, 233, 235). He is aware
that some of these subterranean reservoirs contain fish, about
which he has some incredible tales to tell. He makes mention
of rivers that sink underground and reappear, as if a matter for
great astonishment. But examples of it may be found in many
limestone districts, where the solution of the rock by underground
water has given rise to tunnels, passages, and caverns into which,
when their roofs give way, surface streams may be engulfed, to
break out again from other openings at lower levels (141). The
author concludes this part of his argument by asking if anybody
is ignorant that there are some standing waters which have no
bottom, whence, he contends, it is shown that this water is the
perpetual source of large rivers.

The various kinds of taste possessed by natural waters are then
discussed, and some marvellous illustrations are given of their
effects. Allusion is made to medicinal springs, to petrifying
waters, to some with extraordinary dyeing properties, and to



NOTES 329

others with neither taste nor smell, but rapidly fatal to the drinker
by immediately hardening and binding the intestines. Refer
ence is also included to certain kinds of springs, of which the
volcanic tracts of Italy supply good examples. Such were those
which killed visitors who peered down into the caverns where
their waters lurk, and suffocated birds that flew over them.
Doubtless many tales were told of the effects of such emanations
of carbonic acid gas, like that of the Grotto del Cane which, near
Naples, still preserves their classic reputation (134, 261). Again,
the same volcanic districts furnished instances of warm, sometimes
even boiling, springs, and in alluding to them the author quotes
the opinion of Empedocles, who was doubtless familiar with them
in Sicily. To complete his record of marvels, the author cites
some lakes on which islands float to and fro, of which good illus
trations, due to a matted growth of vegetation, were then well
known in the Vadimonian Lake (Lago di Bassano), 1 and he
mentions other lakes in which he had equal faith, with water so
heavy that brickbats would float upon it, and nothing, however
heavy, not even hard solid stones, would go to the bottom.

Seneca is inclined to agree with some philosophers that
certain rivers of peculiar and inexplicable character were created
along with the world, and he specially cites the Danube and
Nile as examples, these vast streams being too remarkable to have
had the same origin as other rivers. Accordingly he reserves
the Nile for consideration in a later part of his volume (166).
There is another kind of water which, with his Stoic brethren,
he places at the beginning of the world the great ocean and
every sea that flows from it between the lands. Yet he found no
place in any part of the treatise for a discussion of the phenomena
of the ocean.

The Book closes with a vivid description of the probable
catastrophe by which the end of the world will be brought about.
That the present condition of things will be swept away to make
room for another and better race of men he assumes as a matter
of certainty, and he tries to picture by what Dhysical means the
destruction will probably be effected. He is certain that it will
be by no one agency, but that all the energies of the world will
be called forth to compass the destruction of the human race,
nothing being difficult to nature, especially when she is hurrying
towards her end. The picture which is given of the progress of
the great deluge forms by far the most striking piece of writing
in the volume. It ends somewhat inartistically in some gibing
criticism of a quotation from Ovid. But the poetic afflatus had
not been quite quenched. The author immediately returns to
1 Pliny, Hist. Nat. ii. 96. Pliny the Younger, Epist. viii. 20.



330 PHYSICAL SCIENCE

the subject in the succeeding and final chapters, and after enume
rating the different agencies that may be called out to effect the
destruction of the world, he draws a lurid scene when a single
day will see the burial of the whole human race. 1 After this
act of divine wrath has been accomplished, the waters will
disappear below ground, the sea will retire to its own abode, and
on the renovated earth every animal will be created afresh, and a
new race of men will be installed, ignorant of sin and born under
better auspices.



BOOK IV

This section of the treatise begins with a denunciation of
flattery and ends with another against luxury. Neither the
preface nor the concluding chapter have any obvious connection
with the text between them. It is curious to note that while
Seneca here warns his friend Lucilius against flatterers, and in
culcates how their approaches are to be met, he himself in this
very volume perpetrates four pieces of flattery to the despicable
but all-powerful Nero. He quotes a prosaic line from a poem of
the emperor s, which he characterises as " most elegant " (dis-
ertissime^ 25). He refers to Nero as most devoted to truth as
well as to the other virtues (235); he refers to the advent of a
comet which appearing in Nero s reign had redeemed these
heavenly bodies from their evil repute (290), and he describes
that reign as "most joyous " (laetisstmus, 294). The old courtier,
so long habituated to the language of flattery, was perhaps hardly
conscious that he was here making use of it, or he may naturally
have reflected that at a time when the emperor had ceased to
bear him any good will, the absence of the customary adulation
might cause as much offence as if a direct insult were intended.

When from his ethical lecture he turns to resume his physical
disquisitions, it is the mysterious Nile to which he devotes atten
tion. After a brief contradiction of the statement of some
philosophers that the Nile and the Danube are similar in their
characters, he enumerates some of the well-known peculiarities
of the river of Egypt. A problem which greatly exercised the
minds of the philosophers of antiquity, and which has only been
finally solved in our own day, was the cause of the annual rise
of the Nile on which the fertility of Egypt depended. Seneca

1 So Lucretius :

. . . maria ac terras caelumque
una dies dabit exitio.

De Rer. Nat. v. 92, 94.



NOTES 331

says with justice that if the point of the river could be ascertained
where the rise begins the question would be settled. He does
not appear to have known much about the river, for he believed
that the water is for the first time collected into a single channel
at Philae. In his account of that place and of the cataract
there (168, 169), he speaks of the river s egress from Ethiopia,
and of deserts which are crossed by the trade route to the Red
Sea. In a subsequent part of the treatise he gives the inter
esting and important information that he had himself seen and
conversed with two centurions who had been despatched by Nero
to discover the source of the Nile (235). From them he learnt
that they had penetrated far into the heart of Africa, and had
reached a region of illimitable marshes where the river was so
covered and impeded with vegetation that neither on foot nor by
boat could it be ascended. There can be no doubt that these
enterprising explorers had come to the sudd, which in recent
years has been found so serious an impediment to navigation.
They informed Seneca that in the marsh region they had seen
with their own eyes " two rocks from which an enormous body
of the river came out." There are apparently no rocks along
the course of the Nile in the present marsh region, which is a
vast flat, and it is therefore difficult to conjecture to what the
two military surveyors allude. Possibly they saw the mouth of
some affluent of the main stream such as the Khor Adar, or the
sudd may have extended further north than it does now.

Seneca s account of the Nile derived from travellers and
previous writers gives a clear summary of what was then known
about the river, but of more interest is his discussion of the
opinions that had been propounded before his time as to the
cause of the annual rise. He first quotes the view of Anaxagoras,
shared by the Greek tragedians and widely accepted, that this
rise was due to the melting of snow on the uplands of Ethiopia.
This idea he cogently combats by adducing various kinds of
evidence of the great warmth of the climate in those southern
regions. Some of these proofs, indeed, are exaggerations, as where
he affirms that silver is unsoldered or melted. But one of his
proofs, drawn from the habits of the animals of the country, is
worthy of notice. He remarks that no hibernating creature is
found there, and that even in midwinter the serpent is seen above
ground. He argues that in Africa, as in Europe, melting snow
would swell the rivers in spring and early summer, whereas the
Nile flood continues to rise later during four months.

In a subsequent part of this treatise (235) allusion is made to
an explanation which had been given of the rise of the Nile, that
it is due not to the fall of rain from above but to the outflow of



332 PHYSICAL SCIENCE

water from within the earth, and it is in connection with this
opinion that he cites the experience of Nero s two centurions
above referred to, as if he were disposed to believe that what
these explorers saw was really a vast body of water issuing from
underground.

The opinion of Thales is next criticised that the Etesian or
northerly winds drive the waters of the Mediterranean against the
mouths of the Nile and consequently pond back the waters of
the river. This view was of course entirely erroneous, but though
Seneca rejects it, he does not seem to have quite understood it,
for he argues that, coming from the same quarter as the winds,
the Nile water should not have been turbid, but clear and blue,
like that of the sea. In commenting upon the futile support
given by Euthymenes of Marseilles to the idea of Thales, Seneca
throws light on the wide extent to which the coasts of the outer
sea had then been made known by trading vessels.

In rejecting another explanation proposed by Oenopides of
Chios, the author shows that he is aware of the fact that caves
and wells are warm in winter and cool in summer, and that he
has partly divined the reason, when he states that in winter they
are warm since they do not admit the frosty air from without and
in summer they feel cold because the warm air from outside has
not penetrated into their recesses. He returns to this subject in
Book VI. (241).!

After mentioning and dismissing a grotesque suggestion of
Diogenes of Apollonia, Seneca suddenly drops the discussion of
the Nile and passes on to the subject of hail. It is obvious that
there is here a serious gap in the text. It is not probable that
he meant to leave off his examination into the probable sources of
the Nile without stating his own view of a matter which had been
so long the subject of wonder and debate. Either, therefore, he
never completed this section of his treatise, or a portion of the
work has been lost.

The remainder of Book IV. is taken up with a desultory
discussion of the subjects of hail and snow, written when the
author must have been in a somewhat frivolous mood. He
begins by telling Lucilius that if he were to assert that hail is
produced as ice is with us, a whole cloud being frozen, he would
be rather audacious. So he will imitate the chroniclers, who
after they have told a great many lies, refuse to be responsible
for some one statement, and refer for its truth to the authorities.

1 The various ancient interpretations of the cause of the Nile s annual rise
are succinctly given by Lucretius (De Rer. Nat. vi. 712-37), but he does
not indicate a preference for any one in particular, though he devotes most
space to the influence of the Etesian winds.



NOTES 333

If, therefore, his friend doubts his word, he will call in Posidonius,
who will tell him that hail is formed from a watery cloud just
turned into liquid. No teacher is needed to explain why pellets
of hail are round, for all drops take that shape. Hail is nothing
else than suspended ice, and snow is suspended hoar-frost. In
this light vein Seneca thinks he has finished the subject and
might dismiss it, but he cannot resist the temptation to continue
the persiflage a little further. He quotes in a bantering style
some of the opinions of his brother Stoics, and after this long
preamble begins an inquiry into the distribution of density and
temperature in the atmosphere.

It would have been interesting had he seriously and fully
stated what was known or surmised on this last topic, but he
dismisses it in three short chapters. We learn from these that
he regarded the air to be densest next the earth, and that as all
things retain heat better the denser and more compact they are,
so the air becomes less warm in proportion to its height (iS/j.). 1
The opinion of some persons, that the air on mountain summits
ought to be warmer because they are nearer the sun, is sagaciously
controverted, and the insignificance of all inequalities on the
surface of the earth in comparison with the distance from the
earth to the sun is forcibly expressed and illustrated.

The subject of snow and hail is briefly reintroduced at the
end of the Book, probably for the purpose of affording a con
venient introduction to the invective against luxury which fills
the concluding chapter. The preservation of snow in ice-houses,
and its use in the reparation of jaded appetites by cooling drinks,
calls forth a denunciation of the young rakes of his day, which
closes the discussion.



BOOK V

The movements of the atmosphere form the subject of dis
cussion in this part of the treatise. In the first chapter the
author seeks for an exact definition of the term " Wind " (ventus),
and ends by adopting one which is obviously inaccurate " wind
is air flowing in one direction," for as he afterwards speaks of
whirlwinds he was well aware that the movement may be in every
direction, or vorticose. Dismissing the opinion of Democritus
as to the origin of wind, he states that in his judgment wind may
arise from four different causes. First ; The earth itself breathes
forth a vast amount of air from its interior, where there are large

1 This view hardly agrees with what is expressed in Book II. (60, 61),
but it more accurately expresses the fact.



334 PHYSICAL SCIENCE

rivers and lakes, and where the moist air naturally gives rise to
blasts of wind. Second ; Long-continued evaporation carries the
terrestrial emanations aloft, where the intermingling of the breath
results in wind. Third ; Much more important is the fact that the
air in its very constitution possesses an innate power of motion ;
we cannot imagine that while we ourselves are endowed with a
capacity of movement and water has this power also the atmo
sphere should be left inert and immovable (197). Fourth ; Some
times the sun is itself the cause of wind, when he loosens and
expands the thick air (198).

In this enumeration allusion is made to one or two features
of natural history which the author appears to accept as fact.
He thinks there must be some vital force in water, otherwise it
could not bring forth animals and plants, as we know it does.
But not only water; fire, too, which devours everything, possesses
this generative capacity, for, unlikely as it might be thought, it
is nevertheless true that fire gives birth to some animals. The
air, too, has some vital energy, as it alternately thickens, con
tracts, and expands, and rids itself of its impurities. The portion
of it contained within the earth is asserted in a later part of the
volume to be the source of the life of the vegetation at the surface
(244).

The local winds, now known as "land and sea breezes," are
next discussed (198). Instead of the simple explanation which
in our own day has shown these aerial currents to be beautiful
examples of the results of diurnal variations of atmospheric pres
sure, the ancient theory represented that during the day the
exhalations from the land are borne on high to supply the sun
with nourishment, while at night, as they are not needed for that
purpose, they accumulate until they have filled up a given space
enclosed by mountains. When in such a space there is no more
room, they move towards the quarter to which they can most
easily escape ; hence the wind. It is curious, however, to note
that Seneca only describes the land breeze, which falls away as
the morning advances. He does not specially refer to the
equally characteristic sea breeze, which springs up after the other
dies down, and continues during the day, until in the evening it
is again replaced by the land breeze.

The important Etesian or northerly winds, with all their
important local modifications in the Mediterranean basin, must
have been a subject of constant observation to the Greeks and
Romans. There was a general belief that as these winds reap
peared regularly in summer, they were in some way connected
with the position of the sun in the firmament. Seneca, after
briefly stating this opinion, dissents from it on the ground that,



NOTES 335

as the sun reduces the strength of the morning or land breeze, it
cannot be through his influence that the Etesian winds then
begin to blow. But he does not explain how he would him
self account for their occurrence. They are now known to
be further illustrations of the influence of atmospheric pressure.
In summer, when the hot region of the Sahara becomes a vast
area of low pressure, the air streams into it from the north across
the Mediterranean basin.

The account given of cloud winds (203) is an excellent illus
tration of the utter ignorance of the philosophers of antiquity
of the very rudiments of meteorology, and, at the same time, of
the confidence with which they offered their explanations of the
phenomena of the atmosphere. Even now, after prolonged
investigation, the laws that regulate the production of furious
winds and gusts connected with clouds are far from being fully
understood. The boldest meteorologist of to-day, with all his
detailed experience, would hesitate to express his opinion as dog
matically as is done in the text. The idea that air accumulating
either above ground or below acquires a vast disruptive force,
obtained wide credence in early times. It was this pent-up
accumulation which was supposed to burst clouds asunder and
produce thunder-storms, while the same energy in caverns under
ground led to earthquakes and the eruptions of volcanoes.

The occurrence of whirlwinds is explained by Seneca from the
analogy of eddies in a river. As the water meets with impedi
ments in its flow, it is driven back and made to whirl round
before it can continue the onward current, so the wind, as long
as it meets with no obstacle, sweeps on, but when it is thrown
back by any projection in its course, or is collected together into
a highly inclined narrow pipe, it whirls round upon itself like the
eddies of a river. But the cause of the vorticose movement
where there is no visible impediment is, of course, left un
accounted for.

In the fifteenth chapter of this Book a story is told of Philip
of Macedon, who sent down a party of miners to examine an old
mine. The men brought back to daylight a wonderful tale of
vast caverns with high over-arching roofs, and filled with huge rivers
and vast lakes. If the author s intention was to connect the
spaciousness of these underground chambers with the operations
of ancient miners, he was sadly mistaken, since at no time has
metal-mining led to the excavation of huge caverns ; on the con
trary, it has always been pursued in narrow shafts and passages.
If the report brought back to the king was veracious, his emis
saries had only come upon a series of natural grottos and tunnels,
such as are of common occurrence in limestone districts, and



336 PHYSICAL SCIENCE

which have no connection whatever with mining. 1 But the
narrative served Seneca s purpose, since it furnished him with the
occasion for a diatribe against the cursed love of gold, which had
apparently been rampant in days long before those of Philip,
and allowed him to supply from his own imagination some addi
tional lurid horrors of the underground world.

When he gets back to his subject, he enters upon an enumera
tion of the various winds known to the ancients. He himself
thinks that as the heavens are divided into twelve sections, so
there are twelve distinct winds, not all felt everywhere, but never
exceeding that number. He does not attempt, however, to
account for them. In his reference to the names given to the
various winds, he gives a quotation from Ovid s Metamorphoses,
in which the more conspicuous winds from the different quarters
are mentioned. To this quotation he adds a line from Virgil s
graphic picture of the storm in the first book of the Aeneid, where
Aeolus opens his cave and the south-east, south, and south-west
winds rush out in fury upon the sea. Seneca remarks, in passing,
that such a collocation of winds as Virgil enumerates could
never have happened in a single tempest. The poet, however,
has made no mistake. In a great cyclonic storm the wind
veers round with the compass from south-east by south to south
west. And even if Virgil had added the north wind, which the
philosopher says he left out, he would only have followed the
invariable course of the winds in the cyclones of the northern
hemisphere, which circle round towards the north as the storm
area is passing eastward.

In conclusion, the author points out the teleological signifi
cance of the winds, and is thence led to repeat the time-honoured
reproach against human iniquity which turns the winds from
their beneficent intention to purposes of war.



BOOK VI

This is, perhaps, the most valuable part of the volume, for it
contains more of the author s own observations than the rest of
the work. It deals more particularly with the great earthquake
of 5th February A.D. 63, which occurred in his own country,
and about which he could collect information at first hand. As
already mentioned, the subject of earthquakes had long fascinated

1 It is possible that these ancient mines were driven in search of metal
seams or veins traversing limestone, like those of lead among the caverned
limestones of Derbyshire.



NOTES 337



him, and he had published, in his youth, a volume about it. The
calamity which brought so much injury to the towns of Campania
was more especially likely to enlist his vivid interest, for the
region that had been convulsed was with him a well-known and
favourite part of Italy, where he often came to spend, on the
shores of the Bay of Naples, such leisure as the life in Rome
allowed him. Besides, it was the native district of Lucilius, to
whom the volume was addressed, and whose town of Pompeii
had suffered from the shock. 1 Hence he here plunges at once
into details of the damage caused by this particular earthquake.
As a prelude to his inquiry into the whole question of the origin
of such catastrophes, he indulges in reflections on their appalling
nature. Some of the unfortunate residents in the convulsed dis
trict had fled from it, vowing never to return. But where, the
writer asks, can they be sure of safety, seeing that no quarter of
the world is exempt from this form of danger ? He urges that it
is at least some consolation to be assured that such calamities
are not the work of angry gods, as was popularly believed, but
are traceable to their own special causes in the processes of
nature (228).

He then considers the various opinions entertained on this
subject by earlier writers, which, on the whole, he regards as crude
and inexact. The cause of earthquakes had been found in water,
fire, air, and the earth itself, or in a combination of several of
these agencies, or even in the co-operation of the whole of them.
As regards the action of water, he dismisses the opinion of
Thales (231), but in the statements of other authors, who maintain
the power of internal water in causing earthquakes, he sees a greater
probability of truth. He fully admits the existence of large rivers
and extensive lakes inside the earth, and that in these dark unin
habited regions flooded rivers undermining their banks, and a
swollen sea lashed into fury by the subterranean winds, may com
municate shocks to the surface of the earth (234).

That fire is the origin of earthquakes had been held by various
philosophers, who, however, differed as to the manner in which
the fire acts. Anaxagoras thought it was by explosions caused
from the collision of underground clouds (236); others held that
the immense mass of vapour produced by the subterranean
conflagrations as it accumulates may exert such a pressure as to

1 In Seneca s letters, frequent reference is made to his visits to the district.
He seems generally to have taken a villa at Baiae, or some adjacent place on
that western part of the coast. He appears to have been a poor sailor, glad
to make for the nearest landing-place between Baiae and Naples, so as to
escape from the pangs of sea- sickness. On one of his excursions he revisited
Pompeii, and was set into a reverie of his youth there. See his Letters,
49, 5i, 53, 55, 57, 7, 77-



338 PHYSICAL SCIENCE

disrupt all obstructions ; or when the pressure is less may cause
no more than a heaving of the surface. The idea that the shock
of an earthquake results from the removal of material underneath,
whereby the stability of the overlying portion is undermined, and
a collapse of the ground ensues, was held in various forms.
Some thought that this destruction arose from extensive combus
tion within the earth. Anaximenes supposed that just as at the
surface, rocks and old buildings yield to the ravages of time and
fall down, so in the interior of the earth similar landslips may
occur and cause shocks to the districts above them (237). 1

But the favourite opinion of antiquity regarded earthquakes
as primarily due to the violent commotion of air. Seneca com
ments on the views of various philosophers, and more especially
Aristotle s, as to the way in which the air acts, and he then pro
ceeds to deliver his own judgment. He has no doubt that,
though some of the other agencies may co-operate, the chief
motive force in earthquakes is air. By no part of nature, he
affirms, is such violent energy displayed as by air ; it kindles fire,
tosses the surface of the waters into waves, destroys large tracts
of the earth, uplifts new mountains, and raises in the midst of
the sea islands never seen before. Not only does air exist above
ground, but it also fills the hollows and interstices of the interior
of the earth, into which it freely enters from the surface.
Nothing in nature is so restless as air, and the earth cannot but
be affected by the movements of the air included in its inside.
The author agrees with the general opinion that when the air
begins to be agitated in a subterranean cavern which it has filled,
pressed by that which is still entering, it struggles to escape, and,
when it does so, emerges with a violence proportionate to the
narrowness of the passage for its exit. But if unable to make
its way out, it becomes furious, acts like a swollen impetuous
river, and that overthrows everything in its path. 2

It is not difficult to realise how this explanation should have
been accepted in antiquity, and should have held its ground
down even into modern times. The violence of the commotions
of the atmosphere was a familiar feature on the surface of the
earth, although its physical causes, variously guessed at, were
utterly unknown. To minds that had no conception of the very

1 The collapse of the roofs or sides of underground caverns may un
doubtedly be in some instances the cause of local earthquakes. This
origin is enforced by Lucretius :

terra superne tremit magnis concussa ruinis,
subter ubi ingentes speluncas submit aetas.

De Rer. Nat. vi. 544.

2 Lucretius gives a picturesque recital of these views (-De Rer. Nat.



NOTES 339

rudiments of meteorology, there seemed to be no reason why air
inside the earth should not be affected by as violent hurricanes as
the air outside. And as such hurricanes were the most powerful
natural agencies known, their action was not unreasonably in
voked to account for the phenomena of earthquakes. Assuming
that the air in a large subterranean cavern would behave as the free
open atmosphere does, the old philosophers did not find them
selves under the necessity of explaining what was to set the air in
motion within the subterranean recesses and lash it into fury there,
any more than they had to account for tempests above ground.

Obviously, if the air found its way from the outside into the
internal parts of the earth, it must have had equal facilities for
egress. And in the convulsions of an earthquake it might be
supposed to issue with violence through some of the previous
openings or from the rents made at the time. In corroboration
of the truth of the prevalent opinion, it was asserted that after an
earthquake air was found to issue from the ground, but no
account appears to have been preserved of any violent outrush
of air. As a further evidence that it is to the force of air that all
these internal disturbances are due, the author remarks that after
a violent earthquake another shock of equal violence cannot occur,
because the first has opened a passage for the struggling winds.

The progress of investigation has, in modern times, thrown a
flood of light on the phenomena of earthquakes, though there
still remain many problems in the subject which await solution.
It is needless to say that no foundation whatever has been found
for the ancient faith that the air plays the chief part in these
subterranean commotions.

Seneca discusses the nature of earthquake motion. He recog
nises three kinds of movement quaking (succussio], tilting (incli-
natio\ and trembling (vibratio) and he gives illustrations of the
kind of causes to which they may be referred (252). He believes
that the extent of country convulsed by an earthquake depends
upon the area of the subterranean cavern in which the wind
performs its exploits, and as these internal cavities do not con
tinuously underlie vast tracts of the earth s surface, no large
spaces of that surface are simultaneously shaken. In his day
there appears to have been no record of a shock affecting the
whole basin of the Mediterranean Sea. He thinks that no earth
quake ever extends as much as two hundred miles. He cites the
recent calamity in Campania, which did not pass beyond that
district, though marvellous tales about it had spread far and
near, and he gives other examples of the markedly local character
of the phenomena, so far as then known. He affirms that
maritime districts are those most frequently shaken (255, 257),



340 PHYSICAL SCIENCE

in proof of which he gives various instances, including the late
disaster to Pompeii and Herculaneum in a region which had
never been known to be shaken before.

He had received information about the Campanian shock, and
the narrative in which he embodies it has the interest of being
the most detailed account of an earthquake that has come down
to us from antiquity. First of all, as already mentioned, he states
that the movement was confined to the district of Campania, no
mention being made of its having been felt even so near as Rome.
He notices the injury done to Herculaneum and to Naples by
the damage of public and private buildings ; bronze statues were
split open and some people were driven out of their minds. He
records that Campania continued to tremble for some days after
the great shock. He had heard that a flock of six hundred sheep
was said to have been killed near Pompeii. Accepting the report
as true, he sees no reason to suppose that the animals died of
fright, but thinks it not unlikely that they were poisoned by the
ascent of pestilential vapours from the ground. This conjecture of
his receives perhaps some support from the fact that in this volcanic
district, after an eruption of Vesuvius, so much carbonic acid gas
has been said to escape from the ground as to suffocate hundreds
of hares, pheasants, and partridges. But the most vivid experience
of the earthquake which he narrates is that of a grave philosophic
friend who, when in his bath, saw the tiles of the floor separate
from each other, allowing the water to sink through the opened
joints, while the next moment, as the pavement closed again, the
water was forced out all bubbling. A better illustration of the
transit of a wave of shock could not be desired.

Seneca was prepared to believe that great changes had been
wrought by earthquakes on the face of the land. He cites in
support of this view some remarkable examples which had
occurred within the times of human history, such as the sinking
of the towns of Buris and Helice, the disappearance wholly or
partially of the island of Atalanta, and the subsidence of Sidon
(256). He refers also to various striking features of landscape
in different regions which had been popularly assigned to the
work of earthquakes, such as the separation of Ossa and Olympus,
the disruption of Sicily from the Italian shore, and the severance
of Spain from the continent of Africa (263).

That the phenomena of earthquakes are closely connected
with those of volcanoes was the general belief in antiquity, and
continued to be accepted up to the middle of last century. It was
believed in early days that just as the collision of clouds during
storms produces the fire seen in lightning, so during the tempes
tuous agitation of the air within the earth, such heat is generated



NOTES 341

as to set fire to beds of sulphur or other combustible materials,
and thus that rocks are melted and are forced up to the surface
by the vast energy of the escaping air. 1 It is to be regretted that
Seneca has not left an account of his own opinions on this subject,
but from the allusions in the present treatise he may be inferred
to have held the prevalent opinion. He alludes in various
passages to volcanic eruptions that had taken place in his own
time, or not long before, in the Mediterranean basin. An eruption
of Etna is briefly noticed, when the mountain was in violent
eruption, ejecting such a quantity of fine burning sand and dust
as to turn day into night, accompanied with much thunder and
lightning (77). This may have been the eruption alluded to in
similar language by Cicero, who adds that for two days nobody
could see his neighbour. 2 Seneca further cites two eruptions in
the Aegean Sea, one of which had taken place in his own time,
when a new island was upraised "by the force of air." He
alludes to Thera and Therasia, and the interesting account
given by Posidonius of the uprise of an island in the same sea,
with attendant circumstances closely resembling those of the
eruptions at Santorin in modern times (73, 252). According to
Asclepiodotus, the fire, after overcoming the resistance of the
thick mass of sea, shot up above sea-level to a height of two
hundred paces.

From a consideration of the causes of earthquakes the author
is led by his accustomed train of thought to draw the ethical
lessons which the subject suggested to him. He repeats his
belief that against the perils of earthquakes, as against all the
other dangers and fears of life, the only assurance is to be
obtained from elevating studies and a contemplation of nature
(265). It matters not when or in what form we shall quit life,
whether from some trifle or from a world-wide catastrophe. To
be happy without fear of anything that may befall us, we must
carry our life in our hands, steeling ourselves against fear, and
prepared even to welcome death as the advent of a friend.



BOOK VII

After a brief introduction, marked by no little elegance and
literary skill, the author introduces the subject of the heavenly

1 This view of the nature of volcanic energy is graphically expressed by
Lucretius (op. cit. vi. 639-702).

2 De Nat. Dear. ii. 38. See also Lucretius (ib. vi. 641), who describes
the more conspicuous features of an eruption, and concludes with the line
ne dubites quin haec animal turbida sit vis (693).



342 PHYSICAL SCIENCE

bodies, and more especially of Comets which he is to discuss in
this Book. He proposes at the outset to endeavour to ascertain
whether the earth stands still while the universe revolves round
it, or if it is the universe that remains at rest while the earth
revolves. But he is led on from one topic to another, without
having arrived at a definite solution of this problem when the
volume comes to an end. From various expressions, however,
it may be inferred that he adhered to the primitive belief that it
is the universe which goes round the earth. Thus in Chapter IX.
he speaks of the movement that drags the universe along and
asks what is swifter than that revolution (281). The heavenly
bodies may not stand or turn aside, they all move onward with
the irrevocable movement of this eternal creation (299).

The opinions of various philosophers on comets are quoted
and criticised. He is especially severe in his comments on
Epigenes, who thought that comets are produced somewhat as
fires are excited by whirlwinds. The Greek threefold classification
of comets is cited, and then Artemidorus comes in for his share
of vituperation ; to disprove his theory of the firmament being a
solid roof to the world would be, in the author s opinion, nothing
but beating the air. Ephorus fares no better, being briefly dis
missed as often deceiving and often deceived. Apollonius of
Myndus held that many comets are distinct planetary bodies,
which wax and wane like the planets, being brightest when they
are nearest us and growing dimmer as they recede to a greater
distance. But Seneca refuses to admit that they have the
character of true planets ; in his view they are insubstantial
irregular fire (291). But he does not agree with his Stoic
brethren in regarding them as generated in dense air and pursuing
their course according to where they can find fuel to sustain
them (292-4). He conceives that they are not mere sudden
and transient fires, but belong to the eternal works of nature.
They steadily traverse their course, and he can understand that
they may have such wide orbits as to carry them far beyond the
limits of the Zodiac (296). He can see no reason why the five
planets then known should be the only stars that move across
the sky, though others had not yet been discovered. Astronomy,
he remarks, is in its infancy, many mysteries of nature remain
still to be discovered, and the day will come when posterity will
marvel at our ignorance of things which will then appear to be
so evident. Some future observer will demonstrate the paths of
the comets, why they wander so far from the other stars, and
what is their size and constitution. We may be content with
what we have found out, and leave something for posterity to
discover.



NOTES 343

In a tone of sad pessimism he brings his volume to a close.
From a contemplation of the glories that might be achieved by
mankind in searching out the marvels of creation he turns to his
own age and his own country, only to see on every side proofs
of decadence. No one now cared for the pursuit of wisdom.
Philosophy and every liberal study were neglected. The schools
of philosophy were dying. If his countrymen even now would
set themselves with all their energy to the task, if the young
would give their sober attention and the elders would teach them,
they would scarcely succeed in reaching the bottom of the well
in which truth lies. Meanwhile they were searching merely on
the surface of the ground and with but a slack hand.



NOTES BY TRANSLATOR

"AIR"

THE word "air" occurs in the text over 200 times, but not
always as a translation of the same Latin word. With a term so
elastic and so ambiguous it would have been mere pedantry to
attempt a uniform rendering ; and indeed such uniform rendering
would have been more misleading than the course adopted of
rendering according to the context, which the idiom of our language
seemed to demand.

Seneca has two main terms for air aer and spiritus.
Aer means, generally speaking, either air generically, or the
atmosphere specifically. Spiritus, on the other hand, denotes
air under certain conditions of tension, or strain, or pressure,
when it is capable of exerting force or violence ; to its influence
are attributed many effects due in reality to gases, or other causes.
On p. 52, 1. i, we have the definition "air (spiritus} is the atmo
sphere (aer) in violent motion"; and on p. 205 the concluding
words of V. xiii. are "air differs from wind in degree alone. A more
violent air is a wind; air in turn is gently flowing atmosphere,"
where again spiritus is "air" and aer "atmosphere."

Again, in the Aetna, 1. 212, we read, "The winds when
inflated are called spirit ; when in subsidence, air " (Professor
Ellis s translation), where the same terms spiritus and aer are
employed. 1

Now if our author had been consistent in the use of the
words, there would have been a strong case for a uniform adop
tion of " air " and " atmosphere," whenever they occurred. But
numerous passages might be cited to show that he interchanges
the words without apparent motive, just as we do " air " and
"atmosphere." For example, on p. 69, 1. 2, "So fire will pass

1 For a discussion of the meaning of the term spiritus and the parallelisms
in its use by Seneca and the author of the Aetna, see Professor Ellis s edition
of that poem, Prolegomena, pp. xl-xliii.

344



NOTES B Y TRANSLA TOR 345

into air (spiritus)" while on p. 71, 1. 9, "the air (acr\ which is
interchangeable with fire." Again, on p. 75, 1. 6, "When the
clouds have enclosed air" (spiritus); 1. 26, "atmosphere (aer)
shut up in a hollow cloud." A still more conclusive case,
though the passage is probably in other respects corrupt, occurs
in the last sentence of c. xxix. p. 77, where the first "air" is
spirituS) the second, a mere synonym or variant, is aer.
Cf. p. 187, 1. 27, and the passages cited below from pp. 245,
249, 251, 259, 260.

The translator has little choice. He must follow his author,
and, where the latter makes a distinction, must endeavour to
reproduce it ; otherwise he must, as the author did, observe the
idiom of his own language.

In accordance with this principle aer is usually translated
"atmosphere," and spiritus "air"; but circumstances have
rendered unavoidable a considerable number of exceptions.

The discussion of phenomena in which air plays a part is
contained chiefly in Books II. and VI., and here the distinction
of terms in English has been, so far as practicable, maintained.
In Book II. "air" is a translation of aer about a dozen of
times out of a total of over fifty times that " air " occurs, and in
Book VI. about half a dozen out of a total of nearly seventy.

The following is a list of the places in which " air " translates
aer :

Book I. throughout.

Book II. pp. 56, 11. 20, 21 ; 57, 11. 17, 22; 58, 1. 3; 59,
1. 26; 61, 1. 18 ; 66, 1. 12; 71, 1. 9; 72, 1. 22; 77, 1. 17; 98,
1. 26 ; IOT, 1. 28.

Book III. pp. 1 20, 11. 8, 9 (four times); 121, 11. 11-20
(five times); 123,1.28; 129,1.3; 134, 11. 26, 28 ; 135, 1. i ;
140, 1. 29.

Book IV. pp. 176, 11. 6, 9; 184, 1. 2 ; 186, 1. 16.

Book V. pp. 195, 1. 32 ; 196, 1. 7 ; 198, 1. 3 ; 199, 1. 16 ;
202, 1. 6 ; 205, 1. 1 1 ; 206, 1. 3 ; 211, 11. 14, 20.

Book VI. pp. 245, 1. 28; 249, 1. 10 ; 251, 11. 8, 9; 259,
1. 7 ; 260, 11. 26, 29.

Book VII. throughout, with three exceptions^ viz. pp. 277,
1. 26 : 279, 1. 1 6 ; 281, 1. 4.

In a few cases " air " occurs as a more explicit representation
of a pronoun or an adjective which implies it : in these instances
the context is generally a sufficient guide. Spiritus^ too, has
sometimes quite a different rendering, e.g. breath.

On pp. in, 139, 152, "air" is used of a very slight breeze,
the very gentlest breath of wind, and represents aura a good
illustration of the ambiguity of language.



QUOTATIONS

SENECA is fond of illustrating his subject by passages from the
poets. His favourites are Virgil and Ovid, and only once does
he quote Lucretius, whose work was much more analogous to his
own. The quotations are apparently from memory and betray
occasional inaccuracies, as even the best memories will.
The following is a list of the references :

Book I. Pref., 8 (p, 6). Virg. Aen. iv. 404.

i. 4 (10). Virg. Aen. v. 528.

iii. 4 (17). Ovid, Metamorp, vi. 65 7,

v. 6 (25). Nero in an unknown poem: one or two
other tags of that versatile tyrant have been
preserved.

vi. i (28). Virg. Georg. i. 380. i.

xi. 2 (35). Virg. Georg. ii. 95. 6.

xiv. 2 (38). Virg. Georg. i. 367. (cf. VII. xx. i).

xvii. 5 (45). Virg. Eclog. ii. 25. 6.
Book II. i. 2 (51). Ovid, Metamorp. i. 55.

xliv. i (91). Ovid, Metamorp. iii. 305-7.

Book III. Pref., 3 (109). Origin unknown: a somewhat similar
sentiment occurs in Aetna, 24.

i. i (114). Ovid, Metamorp. iii. 407.

i. i (114). Virg. Aen. i. 245. 6.

i. i (114). Lucilius, to whom the Q.N. was addressed.
If he was the author of Aetna, as seems not improb
able, he may have written other poems on Sicilian
topography.

xx. 2 (133). Ovid, Metamorp. xv. 313. 4 (cf. Ibid.
xi. 3 sqq.).

xx. 4 (134). Ovid, Metamorp. xv. 321.

xx. 5 (134). Ovid, Metamorp. xv. 330. i.

xxvi. 3 (142). Ovid, Metamorp. xv. 273-6.

xxvi. 5 (142). Virg. Eclog. x. 4. 5.

xxvii. 12 (147). Ovid, Metamorp. i. 292.
346



QUOTATIONS 347



Book III. xxvii. 12 (147). Ovid, Metamorp. i. 304.

xxvii. 13 (148). Ovid, Metamorp. i. 285. 290.

xxviii. 2 (148). Ovid, Metamorp. i. 272.
Book IV. Pref., 17 (165). Virg. Aen. iv. 373.

Pref., 17 (165). Ovid, Metamorp. \. 241. 2.

ii. 2 (168). Tib. Eleg. I. vii. 26.

iii. 3 (178). Ovid, Ars Amat. i. 475. 6.

iii. 3 (178). Lucret. De Rerum Nat. i. 313.

iv. 2 (179). Virg. Georg. i. 313.
Book V. i. i (193). Virg. Eclog. ii. 26.

xiv. i (206). Ovid, Metamorp. i. 388.

xvi. i (208). Ovid, Metamorp. i. 61-6.

xvi. 2 (209). Virg. Aen. i. 85.
Book VI. ii. i (225), Virg. Aen. ii. 354.

ii. 8 (227). Both quotation and author are doubtful
another reading attributes the poem to A. Gellius.

xiii. 5 (241). Virg. Aen. vi. 256.

xvii. i (246). Virg. Aen. viii. 728.

xviii. i (247). Virg. Aen. i. 55. 6.

xviii. 3 (248). Virg. Aen. i. 53. 4-

xxii. 3 (253). Virg. Aen. viii. 525.

xxvi. 2 (258). Virg. Aen. iii. 77.

xxix. 3 (262). Virg. Aen. iii. 414-9.
Book VII. x. i (282). Ovid, Metamorp. ii. 71.

xx. i (292). Virg. Georg. i. 367 (cf. I. xiv. 2).

xx. 3 (293). Virg. Aen. ix. 20. i.

xxv. i (298). Virg. Georg. i. 137.

xxviii. i (302). Virg. Georg. i. 392.

xxviii. i (302). Virg. Georg. i. 362.



SOME OF GERCKE S READINGS



Rendering in the Text.
I- P- 5, 7, tne Strymon.

8, i, the explanation . . .

Philosophy.

9, 2, such as ... answer

me.
20, 10, an oar ... water.



37, i, Bothynae (cave-
like . . .).

40, 3, one has seen . . .
( = star-struck).



40, 4, of which more anon.

41, 7, For we judge . . .

foreign body.



II. 51, 2, After "rain, snow,"

56, 2, hold together as one

body.
63, 4, on account of ...

clouds.



348



Translation of Gercke s Text,
the Danube and the Bal
kans,
my opinion.

which each knows the other
cannot answer.

an oar is covered with
shallow water and pre
sents a broken appear
ance.

putei (well-like . . .).

what is struck by them we
call smitten with a flash,
that is, struck without
lightning-bolt, what the
Greeks call da-TtpoTrXrjKra
( = star-struck).

of which we have spoken.

But we judge that it is the
deceptive appearance of
a mirror, which merely
gives a counterfeit repre
sentation of a foreign
body.

add " winds, earthquakes,
lightnings."

be subject to tension.

when it has accumulated,
is thrust violently upward
by the massing of the
clouds.



SOME OF GERCKE S READINGS



349



II. 75, 2, and it might . . .
bladder.



95, 2, a third neither.

98, i, (c. Iv.) dry air.
III. 122, 3, when trees are cut

down.
123, i, air is produced.

132, 3, concealed through
out, until.



142, 5, you have yourself. . .
Virgil.



149, 4, nor do the waters,
etc.



IV. 1 6 1, 8, the stature . .
arena.



173, 19, nor yet the Cay-
strus . . . deep.



and which might with
greater accuracy be called
harsh, because it emits a
sound like that heard
when a bladder.

a third mixed, a fourth
neither.

air in rapid motion.

when trees are full of sap
and not cut down.

Gercke places c. xiv. im
mediately after this.

after "throughout" insert
"in others they run above
ground for some dis
tance."

you, my dear Lucilius, be
lieve the story as (I said)
in the first part [of my
book], and so does Virgil.

nor do the waters find this
a hard task since the sea
mounts from an elevation
equal to that of the earth
(or land). If the heights
be calculated (or if the
average be taken over
the heights), it will appear
that the surface of the
sea is of uniform level.

the text and meaning are
somewhat conjectural.
Gercke reads "the stature
of an ape matched against
a Thracian in the arena."
For " Apollonius Pycta "
he reads "A. the boxer."

nor the Caystrus which lies
beneath Mount Tmolus
increases in summer, and
yet deep snow lies there
constantly as is natural
in those northern regions.
" Tmolo " is an ingenious
and probable emendation.



350



PHYSICAL SCIENCE



IV. 1 86, i, no one . . . virtuous.



VI. 232, 2, and, generally speak
ing ...



244, (c. xv.) to hurry
straight forward.

258, 2, philosophers.

265, 2, (c. xxxi.) soft mate
rials . . hard.



VII. 296, 4, every star cannot but
touch . . zodiac.



by which one may become
only more lettered and
not more virtuous.

if the boats are unduly
sunk, the water uses the
whole force of the bur
thens it upbears, in order
either to pour over them,
or at any rate to rise to
an unwonted height to
right and left.

to blow where it lists.

scholars, [or philologists],
walls undergo more frequent
but more gentle shocks
than the nature of hard
material allows,
no star can traverse its
course without touching
the zodiac, then I say a
comet may have a differ
ent kind of orbit and yet
some point in it may co
incide with the zodiac.



INDEX TO THE "QUAESTIONES
NATURALES"

" prefixed to a name indicates authorities used by Seneca.

a Academy, 307. School and followers of Plato.
Achaia, 142, 224, 225, 235, 288 (adj.), 303. District in

N.W. of southern part of Greece (Morea).
Actors, regard for, 307.
Adriatic, 153.

Adversity, to be faced with joy, in, 112.
Aegean (Sea), 73, 252. Eastern part of the Mediterranean.
Aegium, 257 (2). A leading town in Achaia on the Gulf of

Corinth.

a Aeschylus, 172.
Africa, 117, 212, 236, 263.
Africus (Wind), 210.
Air, tension of, 58; wide diffusion of, 60; transformed into

water, 119, 121; transformed into fire, 120, 121, 205;

kindled by friction, 205, 206, 277; kindled within the

earth, 236, 251 ; the cause of earthquakes, 239-48, 251,

254, 255; enters interior of earth, 254, 255.
Albula, 134. Small stream flowing into the Arno near Tibur

(Tivoli) some 16 miles E. of Rome.
Alexander (the Great), no, 215, 254 (2).
Alexandria, 273.

Alpheiis, 142 (2), 235. River in Elis in Southern Greece.
Alps, 1 10, 173, 184.

Ambracian (Gulf), 153. On W. of Greece (Gulf of Arta).
Ammon ; see Jupiter.
Amphitheatre, jets of water in, 59.
a Anaxagoras, 63, 68, 172, 178, 236, 276. Celebrated Ionian

philosopher, 500-428 B.C.

a Anaximander, 67. Ionian philosopher, 610-547 B.C.
a Anaximenes, 67, 237. Ionian philosopher about 500 B.C.



352 PHYSICAL SCIENCE

Animals, blind in subterranean waters, 129.

Animals, new forms of, discovered in Seneca s time, 305 ;

many still to be found out, 305.
Antiochus, 288. King of Syria, 137-128 B.C.
Antony (Mark), 172.
Ants, mankind compared to, 6.
Apennines, 184.

Apollonia, 12, 68, 176. Town in Illyria.
a Apollonius (of Myndus), 274, 290, 300. Said to have

flourished about the time of Alexander the Great

(330 B.C.). There may be some confusion in the text

between him and the celebrated Pythagorean philosopher,

A. of Tyana, who was born shortly before the Christian

era.
Apollonius Pycta (or pyctes = the boxer), 161. Unknown

otherwise ; apparently a gladiator.
Apulia, 211. District in S.E. of Italy.
Aquarius (sign of the Zodiac), 301.
Aquilo (Wind), 209.

a Aratus, 37. Of Cilicia, astronomical poet, flourished 270 B.C.
Araxes, 246. River in Armenia (Aras).
Arcadia, 122, 137. District in centre of Southern Greece.
a Archelaus, 239. Philosopher, flourished about 450 B.C.

Pupil and partly disciple of Anaxagoras.
Arethusa, 142 (2), 235. Celebrated fountain in Syracuse in

Sicily.

Argestes (Wind), 210.

Argolic, 142. Argolis is a district in N.E. of Southern Greece.
a Aristotle, 8, 9, 10, 19 (2), 33, 63, 240, 242, 276, 277, 302 (2),

303 (2), 304. See Introduction.
a Artemidorus (of Parium), 22, 286 (2), 287. Not otherwise

known.

a Asclepiodotus, 74, 77, 207, 246, 253. Not otherwise known.
Asia, 224, 233. Province on the W. coast of Asia Minor, or

generic name for area E. and N.E. of Europe.
Astronomy (Caelestid), scope of, 51; of Egyptians, 274; of

Chaldaeans, 275; of Greeks, 298.
Atabulus (Wind), 211.
Atalanta, 256. Small island between Euboea and mainland

of Greece. The channel now bears the name Talanta,

which is likewise that of a neighbouring town.
Athens, 211.

a Attalus, 94, 95. Stoic philosopher, one of Seneca s teachers.
Attalus, 288. King of Pergamus, 241-197 B.C.
Atlantic Ocean, 174, 175 (2).



INDEX 353

Atlantic Ocean, growth of trade to ports on shores of, 175.

Atmosphere, friction of, produces fires, 9, 39; upper portion
dry and hot, 39, 60, 65, 78; possesses unity or con
tinuity, 52, 57 ; place of, in universe, 54 ; earthy elements
of, 56, 60 ; tension of, 56 ;; lowest portion dense and
dark, 60, 184; and warmer than the rest, 183; distribu
tion of temperature in, 60, 184; causes of movements
of, 61; relation of, to the ether, 65, 66; adapted to
transmit sound, 77; rarefied, kindles fire, 100, 205; by
violent movement sets itself on fire, 102; proof that it
is never absolutely motionless, 1 93 ; possesses a native
capacity of movement, 197.

Atoms, the world a fortuitous concourse of, 7.

Augury, kinds of, 79, 80, 82.

Augustus, 9, 12, 42, 211, 290.

Auster (Wind), 210.

a Authorities (various, not specified by name, but spoken of as
"certain," "some," etc.), 18, 31, 35, 57, 63, 67, 73, 75,
93, 101, no, 116, 118, 119, 122, 135, 148 (2), 150,
182, 184, 186, 230, 233, 236, 238, 239, 242, 243, 244,
283.

Avarice, denounced, 207.

Bactra, 215. In Central Asia (Balkh).
a Balbillus, 171. Governor of Egypt in Nero s reign, 53.

Balkan Mountains ; see Haemus.

Baths, heating of water of, 136; effect of Campanian earth
quake on tiled floor of, 264.

Bathyllus, 307. A native of Alexandria, freedman at Rome
during reign of Augustus; perfected a pantomimic or
ballet dance.

Bear (Great), 208.

Belus, 151. Babylonian deity.
a Berosus, 151. Priest of Belus, about 250 B.C.

Black Sea ; see Pontus.

Boeotia, 137. District in Central Greece.

Boreas (Wind), 208.

Bothynae (meteors), 37.

Breezes, morning, 195, 198.

Buris ; see Helice.

a Caecina, 86, 94, 95, 100. A friend and correspondent of

Cicero, about 48 B.C.
Caesar (Julius), 166, 213, 290.
Caius (Emperor Caligula), 163, 164.

2 A



354 PHYSICAL SCIENCE

Calabria, 211. District in extreme S.E. of Italy.
a Callimachus, 172. Grammarian and poet; chief librarian

of Alexandrine library, 260-240 B.C.
a Callisthenes, 254 (6), 258, 276, 277. Relative and pupil of

Aristotle, friend and victim of Alexander the Great.
Cambyses, 78. King of Persia, 529-522 B.C.
Campania, 221 (2), 224 (2), 225, 239, 257, 259 (adj.), 264,

265. District in Italy containing Capua, Naples, etc.
Cancer (sign of the Zodiac), 151.
Cannae, 209. In Apulia.
Cannon, ancient types of, 67.
Capitol, 91.

Cappadocia, 138. Centre of Asia Minor.
Capricorn (sign of the Zodiac), 151.
Caria, 132, 142 (adj.). S.W. of Asia Minor.
Carthage, no, 166.
Caspian, 153.
Cassander, 122. Son of Antipater, regent of Macedonia;

eventually king of Macedonia; died 297 B.C.
Castor and Pollux, n. Constellation and sign of the Zodiac

(Gemini).

Cataegis (Wind), 211.
Cataracts (Nile), 168.
Caucasus, 173.
Caves with noxious air, 134 ; felt to be warmer in winter than

in summer, 176, 241.
Caystrus (or Cayster), 173. River in W. of Asia Minor flowing

into the sea near Ephesus.
Chalcis, 246, 257. Chief town of Euboea on Strait at

narrowest point.
a Chaldaeans, 81, 275 (3), 302.

a Charimander (or Charmander), 276. Otherwise unknown.
Charms, laws against, 182.

Charybdis, 153. Whirlpool in Strait of Messina.
Chasmata (meteors), 38.
Chersonese ( = peninsula), 142. Carian or Rhodian on S.W.

of Asia Minor.

Chios, 175. Island and town (Scio) off coast of Asia Minor.
a Cicero, 100.

Ciconians, 133. Tribe in Thrace.
Circius (Wind), 211.
Claudius (Emperor), 290, 294, 304.
Cleonae, 181, 182. Town in Argolis.
Cleopatra, 172 (2). Antony s celebrated partner.
a Clidemus, 99. A philosopher anterior in date to Aristotle.



INDEX 355



Clouds, as sources of lightning and thunder, 10, 62, 63, 64,
75, 203; invisible when we are within them, 24; com
position of, 24; compression of, causes thunder, 67;
produce fire, 70, 74, 100; must be burst before they
emit sound, 76, 98; not necessarily connected with wind,
195; as sources of wind, 203, 204.

Cloud- winds, 203.

Colours (in rainbow), origin of, 21, 25, 30, 31.

Comets, infrequency of, 272, 288, 301 ; what are they? 272 ;
points of resemblance of, to planets, 273; resemblance
to meteors, 275, 276; classes of, 276, 290; not due to
wind, 278, 279-282 ; curved path of, 279 ; long visibility
of, 282 ; distribution and shape of, 283 ; Greek classifica
tion of, 283; different from the planets, 284; examples
of, 288, 290; vast orbits of, 290, 297, 302; vary in
apparent size as they advance or retreat, 291 ; trans
parency of, 291, 300; Stoic opinions regarding, 291-294;
directions of, 294, 303, 304 ; Seneca s opinion, 295, 305;
form of, 300 ; portents from, 302.

a Conon, 274. Astronomer; born at Samos ; lived at Alex
andria about 250 B.C. Said to have been a friend of
Archimedes.

Constellations, 301.

Contentment, duty of, 112.

Continuity or unity, defined, 53.

Corus (Wind), 210.

Corycian (Mt.), 122. The district round Corycus in Cilicia
was famous for saffron.

Crassus, 215. Celebrated Roman, slain in battle in Mesopo
tamia, 53 B.C.

Crete, 123, 153 (adj.).

Crispus Passienus, 160. Stepfather of Nero. Consul in 42.

Crocodiles and dolphins, fight between, 171 ; chase of, 172.

Cutiliae, 139 (2). In the Sabine country, N.E. of Rome.

Cyclades, 147. Group of islands in Grecian Archipelago.

Cyclopes, 91. Jove s fabled armourers with workshops beneath
Etna, Stromboli, etc.

Cyprus, 259.

Dacian, 5.

Danube, as a political boundary, 5, 233 ; alleged remarkable

character of, 135; floods of, 146; contrasted with the

Nile, 166; not swollen in winter, 173.
Darius, 254. King of Persia, 521-485 B.C.
Death, to be faced without fear, 103, 223, 226, 265-268;



356 PHYSICAL SCIENCE

equalises mankind, 223; the introduction to a better

place than earth, 267.
Delos, 258, 259. Perhaps the most famous of "the isles of

Greece."

Deluge, that is to destroy the earth, 143.

a Demetrius, 161. Cynic philosopher, contemporary of Seneca.
Demetrius (father and son), 288. Kings of Syria between

162 and 125 B.C.
a Democritus, 183 (2), 194, 249, 250, 276. The optimist or

" laughing philosopher " of Abdera in Thrace ; said to

have lived 460-361 B.C.
a Diogenes (of Apollonia in Crete), 68, 176, 177. Pupil of

Anaximenes, lived in fifth century B.C.
Dnieper (Borysthenes), 174.
Dog-star, 202.

Dolphins and crocodiles, fight between, 171.
Doris, translated " sea nymph " in the quotation from Virgil,

142.

Dowsers, 127.

Drops, globular form of, 178.
Drunkenness, 134, 188.

Earth, material of, formed from water, 120, 121.

Earth as a whole, place of the, in universe, 5 5 ; formed after
the plan of our bodies, 126, 151, 242, 255; final de
struction of, 143; itself the cause of earthquakes, 237 ;
whether it or the universe revolves, 273.

Earth s interior, water supply in, 119, 206, 233, 234; cold
temperature of, 119, 121; like surface above ground,
128, 206; blind animals in waters of, 129; origin of
wind within, 206, 239, 243, 244, 254; landslips in, 238,
249, 251; store of vital air in, 244, 245.

Earthquakes, causes of, 51, 229, 230, 236, 249; effects of,
121, 221, 229, 257, 259, 262, 263; Campanian (of A.D.
63), 221, 257, 259, 262, 264 ; influence of, on the human
mind, 222, 262; widespread destruction produced by,
223 ; not the work of angry gods, 228 ; Seneca s youth
ful work on, 230; water as the origin of, 231 ; fire as
the origin of, 236, 238; air as the origin of, 239-248,
251, 255, 256, 264; mixed sources of, 249; varieties of
movement in (inclinatio, succussio, tremor), 252; most
frequent near the sea, 255; cause of local extent of, 257;
features of the Campanian, 259-264; the first shock of,
the most violent, 264.

Eclipses, 35, 274, 284, 293.



INDEX 357

Egypt, 6, 167-177 (passim}; great heat in, 173; said not to

be visited by earthquakes, 258.

a Egyptians, ideas of, as to the elements, 125 ; astronomy of, 274.
Elements, interchangeability of, 120, 121, 245; four in

number, 123; contrariety of, 301.
Eleusis, 306. In Attica, N.W. of Athens about 12 miles;

scene of the great Eleusinian mysteries.
Elis, 114, 257. District in S.W. of Southern Greece.
Emanations, terrestrial, feed the sun and stars, 55, 198, 244;
cause thunder, lightning, and commotion of the air, 63,
2 75 > dry and moist, 63, 78.
a Empedocles, 136 (2). Philosopher of Agrigentum in Sicily,

flourished about 444 B.C.
a Ephorus, 289 (3). Greek historian of some repute about

340 B.C.

a Epicurus, 250. Born 342, died 270 B.C.
a Epigenes, 274, 275, 276, 277, 278, 279, 280 (2), 283. A

Greek astronomer of Byzantium of uncertain date.
Erasmus, 142. River of Argolis.
Etesian (Winds), 174 (4), 175, 201 (4), 202 (4), 212.
Ether, characters of the, 65 ; descent of force from the, 68.
Ethiopia, 6, 117, 167, 168, 172, 173, 212, 235. Term was
applied very loosely to all the hinterland of Africa, only
the Mediterranean coast and a portion of the Nile basin
being known to the Greeks.
Etna, 77.
a Etruscans (or Tuscans), 79, 88, 92, 95 (sing.). Etruria lay

immediately N. of the Tiber.
a Eudoxus, 274. Astronomer of Cnidus in Caria, pupil of

Plato, flourished about 366 B.C.
Euphrates, 5, 215.
a Euripides, 173.
Euronotus (Wind), 210.
Europe, 173 (adj.), 233.
Eurus (Wind), 208, 209.
a Euthymenes (of Marseilles), 174, 175 (2). Geographer,

probably about 150 B.C.
Evaporation from the earth, 198, 200, 240.
Expiation, the reason for, 83, 84.
Eyesight swifter than hearing, 64.

a Fabianus (Papirius), 144. Distinguished Stoic, one of

Seneca s teachers.

Falernian (wine), 35. District famous for wine in N. of
Campania.



358 PHYSICAL SCIENCE

Fate, unalterable, 83; nature of, 84, 91; uncertainty of
visitations of, 225.

Favonius (Wind), 210.

Fear, how to be combated, 103, 225, 229, 265, 266, 267;
arises from ignorance, 229 ; leads to loss of reason, 262.

Fidus Annaeus, 161. Apparently a gladiator of gigantic
stature.

Fire, kindled in atmosphere, 39, 62, 64, 70, 100, 102 ; passes
into air, 120 ; artificial modes of producing, by percussion
or friction, 70 ; naturally rises, 71, 102 ; endowed with the
power of producing some animals, 197 ; as the cause of
earthquakes, 236, 238 ; produced in the earth s interior,
251 ; kindled by air, 251.

Fires, celestial, 8, 39, 294, 295, 296.

Fish in underground waters, 129, 132.

Flattery, counsel against, 159.

Floods, the earth to be finally destroyed by, 143, 144.

Fortune, vicissitudes of, in.

Fountains, discharges from, 142.

Fucinus, 1 1 6. Large lake in Sabine country E. of Rome.

Gaetulicus, 163. Cn. Cornelius Lentulus G., put to death

by Caligula 39.
Galatia, 138.
Gallic, 6.

Gallio, 1 6 1, 202. See Introduction.
Gaul, 117, 122 (pi.), 211.
Geography (Terrend), scope of, 51, 52.
Germanicus, 9. Nero Claudius Drusus, brother of the

Emperor Tiberius, died 10 B.C.
Germans, 233.
Germany, 5, 117, 166.
Gibraltar, 175.
Glass, globe of, filled with water magnifies objects, 29 ; cause

of iridescence in, 30.
God, nature of, 3, 4, 7, 8, 91, 305; sends portents, 80;

unchangeable, 84 ; to Him everything is present, 84 ;

His design in creating the winds, 213, 216.
Gods, dread of infernal, 208 ; do not disturb heaven or earth,

228 ; not to be feared, 266.
Gold, lust for, denounced, 5, 208, 215
Greece, 215, 274(2), 298.
Greek, 58, 95, 210, 255.
a Greeks, 12, 13, 15, 34, 39, 40, 140, 169, 198, 203, 205,

209(2), 210, 211, 240, 255, 283.



INDEX 359



Gusts of wind, origin of, 203.

Gylippus, 12. Spartan commander against Athenians at
Syracuse, 414 B.C.

Haemus (Balkan Mountains), 122.

Hail, 177, 1 8 1 ; falls more in summer than winter, 179;

prognostications of, 181.

Halos (crowns), round sun and moon, 12, 14, 34, 41.
Hannibal, no, 209. Famous Carthaginian general in Second

Punic War, 219-201 B.C.
Happiness, how to be gained, 5, 266.
Heavenly bodies, influence of, on rivers, 141 ; on weather, 275 ;

apparent retrogression of some, 299.
Heavens, extent of the, 7 ; contemplation of the starry, 271 \

divisions of the, 210 ; supposed by Artemidorus to be a

solid vault, 286.
Helice and Buris (or Bura), 254, 257, 259, 267, 276,

277, 289. Towns in Achaia swallowed by earthquake

373 B.C
Heracleotic (mouth of the Nile), 171. Most westerly and

largest, not far from Alexandria.
a Heraclitus, 100. Ancient representative of pessimism, "the

weeping philosopher," of Ephesus, toward end of

sixth century B.C.
Herculaneum, 221 (2), 259.
a Homer, 258.
Horizon, 211.
Hostius Quadra, 42. Unknown save for Seneca s unfortunate

mention of him.
Hydissus, 132. Orthography of this Carian town is uncertain ;

Gercke reads Idumus.
Hydraulic organs, 56.

lapygian (Wind), 211.

Ice, 140.

India, 7, 212, 215.

Intermittent action, 128.

Iron, discovery of, 45 ; money made of, 46.

Islands, floating, 139.

Ister (or Hister), a name of the Danube, which see.

Italy, no, 117, 133, 212, 261, 262 (adj.), 263.

Junior; see Lucilius, 168.

Jupiter (Jove), temple of, in African desert (Ammon), 78;



360 PHYSICAL SCIENCE

his thunderbolts, 88, 89, 91, 92; affords lessons to
earthly rulers, 90 ; other names for, 91, 92.
Jupiter, the planet, 284, 299.

Lacedaemonians, 189. Lacedaemon, or Sparta, was in
Laconia, the district in the S.E. of Southern Greece.

Ladon, 257. River in Arcadia, tributary of Alpheus.

Laelius, 268. Friend of the younger Scipio Africanus, consul
140 B.C. Chief interlocutor in Cicero s Dialogue on
Friendship.

Lakes, with dense water, 138, 139; underground, 154; wide
extent of some, 233.

Land and sea breezes, 198.

Landslips, 238, 249, 251 ; effects of, 253.

Latin, 210 (2).

Leo (sign of the Zodiac), 301.

Lepidus, 166 (3). Formed with Augustus and Antony the
Second Triumvirate after Caesar s assassination in
44 B.C.

Libonotus (Wind), 210.

Libyan (Wind), 210.

Life, the proper conduct in, 112, 159, 266; uncertainty of,
226; to be carried in our hand if we desire to live happy
and without fear, 266.

Lightning, 62, 66, 69, 86, 87, 100; effects of, 78, 87, 88,
96; portents indicated by, 79, 81, 82, 86, 92, 94, 95,
215 ; possible pestilential power in, 97; cause of zigzag
course of, 102 ; moral lessons to be derived from a
consideration of, 104; safe retreats from, 223; blinding
effects of, 292 ; connected with the planets, 275.
a Livy (Titus Livius), 209, 213. Roman historian, 59 B.C.-I7.

Lower Sea ; see Propontis.

Lucilius Junior, i, 103, 109, 114, 142, 159(2), 161, 162, 163,
217, 221, 265, 267, 268. See Introduction.

Luxury, introduction of, 45, 46; growth of, 47, 188; illustra
tions of, 129, 187; denunciation of, 130, 187, 306.

Lycia, 140. District S.W. of Asia Minor.

Lycus, 142. River, probably of Phrygia in Asia Minor,
flowing into the Maeander.

Lydia, 139. District in W. of Asia Minor.

Lyncestis, 134.

Macedonia, 138, 207, 224, 303.

Magnesia, 122. Town of Lydia.

Mankind, compared to ants, 6 ; early ages of, 45, 46 ; final



INDEX 361

destruction of, 147, 152 ; re-creation of, after the deluge,

155 ; world not made only for, 305.
Marmora or Marmara (Sea of) ; see Propontis.
Mars, the planet, 10, 275, 284.
Marseilles, 174.

Marshes, 233 ; of the Nile, 236.
Magalenopolis (or Megalepolis or Megalopolis), 257. Town in

Arcadia.

Melas, 137. River of Boeotia in Central Greece.
Memphis, 170. Great Egyptian city a little above Cairo.
a Menander, 165. Athenian comic poet, 342-291 B.C.
Mercury, the planet, 284.
Messalina, 163. Third wife of Emperor Claudius ; put to

death by Narcissus, 48.
Messana (Messina), 142.
Metalliferous veins, 126.
Metals, melted by lightning, 78, 96 ; denunciation of the

search for the precious, 207, 215.
Meteorology (Subtimta), scope of, 51.
Meteors, 8-n, 37, 38, 40, 275, 276, 292, 293, 296.
a Metrodorus (of Chios), 248 (2). Philosopher who flourished

about 330 B.C. "Sceptic." Disciple of Democritus, perhaps.
Milky Way, 289.

Mind, the human, its nature and seat unknown, 297.
Mines, water in, 154 ; ancient, explored by Philip of Macedon,

207.

Mirrors, 22, 23, 24, 27, 41, 42, 44, 45, 47.
Mock-suns, 35.

Moon, eclipse of, 298; varying colour of, 300.
Moral reflections, Seneca s, 1-8, 42, 44-47, 102-105, 109-

114, 130-132, 143-156, 159-166, 186-190, 207, 213-

217, 222-229, 254, 265-268.
Mountains, insignificance of height of, compared with the

whole mass of the earth, 184.
Mushrooms, 189.

Mylae, 142. Town on N. coast of Sicily, near Messina.
Myndus, 274, 290. Town in Caria.

Naples, partly damaged by earthquake of A.D. 63, 221.

Narcissus, 164. Freedman of Claudius, put to death by
Agrippina, 54.

Natural Philosophy, 3, 8.

Nature, influence of, 3 ; origin of, 7 ; as a synonym for God,
92 ; advantage of the study of, 113, 265 ; finds no task
hard, 144, 154; inadequate conceptions of, 228; study



362 PHYSICAL SCIENCE

of, the highest pursuit, 230; power of variation in, 301 ; in-
exhaustibility of, 306; still most imperfectly known, 306.

Naval wars denounced, 213.

Nebaioth, 208. An Arabian people, put for East in general
Latin form is Nabataei.

Neptune (Earthshaker), 255.

a Nero Caesar, 25, 235, 290, 294 ; probably referred to, though
not named, 90 (last two sentences).

Nicopolis, 259. City in W. of Greece at entrance to Ambracian
Gulf. The word means " city of victory," something like
our oft-recurrent "Victoria."

Nile, unusual character of, 114, 135, 166; physiological effect
of water of, 140; rise of, 141, 167, 169, 172; course
of, 1 6 8, 170, 233; cataracts of, 168; mode of descent
of, 169; delta of, 170, 171; canalisation of, 170;
deposit of, 170, 258; inundation of, 171; supposed
underground supply of, 235 ; Nero s expedition to the,
235; transport of sediment by, 258.

Nonacris, 137. Town in Arcadia.

Notus (Wind), 209.

Nuceria, 221. Town in Campania.

Ocean, 6(2), 112, 119, 135, 143, 153, 155, 231, 254(2), 266.
a Oenopides (of Chios), 175. Mathematician and astronomer,
probably contemporary of Anaxagoras, fifth century B.C.

Olympic, 142 (2). Olympia was in Elis.

Olympus, 257. High mountain in Thessaly, Northern
Greece.

Omens, arranged by Providence, 80; from lightning, 82.

Organs (hydraulic), 56.

Ossa, 257. Mountain in Thessaly, Northern Greece.

Ostia, 41. Town at mouth of Tiber; port of Rome.
a Ovid, 114, 133, 148, 165, 168. Latin poet, 43 B.c.-i8.

Parhelia, 35.

Pamphylia, 211. District on S. of Asia Minor.
a Panaetius, 304. Stoic philosopher of Rhodes, friend of
Laelius and the younger Scipio Africanus ; died 1 1 1 B.C.
Paphos, 259. Town on W. of Cyprus.
Parium, 22. Town in Mysia on N.W. of Asia Minor.
Parthians, 5, 215.
Paterculus, 303. His consulship is said to have been in the

year 60.

Patras, 257. Town at entrance of Gulf of Corinth.
Paulus, 9. L. Aemilius P., consul 181 and 168 B.C.



INDEX 363

Peacock, analogy from colours of, 25.

Peloponnesian (War), 256, 258. Lasted 431-404 B.C. between
Athens and Sparta.

Pencils, 138, 257. Great river draining the plain of
Thessaly and flowing through vale of Tempe between
Olympus and Ossa ; now called Salambria.

Perseus, 9. Last king of Macedonia, 178-168 B.C.

Persia, 208, 215.

Persians, 254.

Pestilential vapours emitted from the ground, 260, 261.

Pharos, 258. Island off Alexandria with famous lighthouse,
united to mainland by Alexander the Great.

Phasis, 174. River of Colchis at E. of Black Sea.

Philae, 168 (3), 169. Island in the Nile, just below
First Cataract. Seneca seems to confuse it with the
so-called island of Meroe, at the junction of the Blue
Nile and Atbara.

Philip, no, 207 (2). Father of Alexander the Great ; king
of Macedonia 359-336 B.C.

Philosophers, debt due to the early, 230 ; credulous folk,
258; severe criticisms of, 125, 175, 288, 289.

Philosophy, divisions of, 3 ; pleasures of, 4, 5 ; benefits con
ferred by, 97; delivers its votaries from fear, 225; re
wards of, 229; decadence of, 307, 308.
a Pindar, 258. Greek poet, 522-442 B.C.

Pithitae, or pithiae (meteors), 38, 40.

Plancus, 1 60. L. Munatius P., a prominent actor in the
civil wars, 48-31 B.C.

Planets, colours of, i o ; enumerated, 275; fixed number of,
284; orbits of, 285; motions of, 288; possibly greater
number of, 297 ; conspicuous movements of, 298.
a Plato, 216.

Pollux, 1 1 ; see Castor.

Pompeii, 221, 259(2).

Pompey, 166 (3). Defeated by Caesar 48 B.C., and assassi
nated shortly after.

Pontus (district in N.E. of Asia Minor), 141.

Pontus (Black Sea), 153, 176, 180 (?).

Portents from meteors, 9, 228, 259; lightning, 79, 86, 93,

94, 95, 215; eclipses, 228; comets, 272, 290, 302.
a Posidonius, 26, 27, 73, 74, 98 (2), 177, 246, 252, 256, 292,
293. A very distinguished Stoic philosopher, president
of that school. Instructor for a time and friend of
Cicero. Prosecuted physical investigations with great
success. Native of Syria. Lived 135-51 B.C.



364 PHYSICAL SCIENCE



Posterity, great increase of knowledge to be attained by, 298.

Predestination, 85.

Prognostications ; see Portents.

Propontis (Sea of Marmora), 153, 176 (Lower Sea).

Providence, 92, 213.

Puteoli, 133. On coast of Campania.

Pylades, 307. A Cilician ; a dancer like Bathyllus.

Pyrenees, 5.
a Pyrrho, 307, Founder of the sect of the Sceptics, native of

Elis ; flourished about fourth century B.C.

a Pythagoras, 307. Flourished in second half of sixth century
B.C.

Pyx, trial of, 180.

Rain, Seneca s observation on descent of, into soil, 117;

share of, in final destruction of the world, 143, 144, 149 ;

seasonal variations of, 179; supposed to be influenced

by incantations, 182.
Rainbow, 16-33.
Rainless countries, 167, 173.
Red Sea, 112, 153, 168.
Regulus, 221. Consul 63.
Reverence, duty of, 304.
Rhaetian, 35. The reference is to wine grown in the N.

of Italy (Cisalpine Gaul).
Rhine, 146 (2), 173, 233.

Rhodians, 142. Island of Rhodes was at S.W. of Asia Minor.
Rhone, 146, 173.
Rivers as political boundaries, 5, 233; sources of supply of,

116; underground, 132, 141, 206, 207, 233, 235;

summer rise of, 141, 173.
Roman, 5, 12, 46, no, 113, 166.
Rome, no, 166, 182, 209, 307.
Roots, disruptive force of, 57.
Rulers, counsel to, 90.

Sacrifice cannot alter fate, 84; to keep off hail, 181.
St. Elmo s Fire, n, 37.
a Sallust, 279. Roman historian, 86-34 B.C.
Sarmatian, 5, 233 (pi.). Roughly speaking, the S. part of

Russia.

Saturn, the planet, 275 (2), 284, 303.
Scipio, 46 (2). The elder Sc. Africanus, victor of Hannibal

at Zama, 202 B.C.
Scironian (Wind), 211.



INDEX 365

Scylla, 153; see Chary bdis.

Scythia, 180, 208. Term used very loosely of region in Central
and Northern Asia, but at times extending to Europe, as
far west as the Danube. Sarmatia of one age was part
of Scythia of another.

Sea, unity of the, 125; coeval with the world, 135; throws
ashore ill-smelling deposits, 142 ; share of, in final de
struction of the earth, 143, 150; current of, from Black
Sea, 176; subterranean, 234.

Sea and land breezes, 198.

Seafaring, condemned, 216.

Sea-water, purged of its salt within the earth, 116.

Sejanus, 9. Notorious instrument of Tiberius ; put to death

3i-

Sela (gleams in the sky), 39.
Self, bondage of slavery to, 113.
Septemtrio (Wind), 210.
Sextii, 307. Father and son in the time of Augustus and

Nero respectively ; taught a combination of Stoic and

Pythagorean doctrines.
Sheep, destruction of, during Campanian earthquake of

A.D. 63, 259.
Sicily and Sicilian, 114, 138, 142 (2), 153, 159, 166(2),

235, 262, 263.
Sidon, 256.
Snow, melting in Ethiopia erroneously supposed to be the

cause of the annual rise of the Nile, 173 ; supplies some

European rivers, 173; on European mountains, 173;

origin of, 178, 179, 182, 186; said to feel colder to

the feet when dry and hard than when slushy and half

melted, 180; artificial use of, 187.
Sophocles, 172.
Soul, divine origin of, 6 ; to be rescued from error and fear

of death, 103.

Sound less rapid than light, 64.
Spain and Spanish, 6, 7, no, 263.
Springs, 118, 121, 127, 136, 142.
Squalls, origin of, 204; short duration of, 281.
Stabiae, 221. Small town on coast of Campania.
Stars, fed by emanations from the earth, 55, 198, 244;

influence of, in human affairs, 81 ; nature of, 273;

transits of, 284; supposed small size of, 288; place of,

in sky, 297 ; varying colours of, 300.
Stars, falling, 10, n, 37, 99, 296.
Statonia, 139. Town in Etruria, about 15 miles from the coast.



366 PHYSICAL SCIENCE

Stoics, 32, 40, 58, 66, 95, 119, 124, 135, 151, 180, 181 (2),

210, 251, 291, 292, 293, 295 (my school).
a Strata, 240. Succeeded Theophrastus as head of the Peri
patetic school in 288 B.C. Native of Lampsacus in
Mysia on the Hellespont.

Streaks in the sky, 33.

Strymon, 5. River of Thrace and Macedonia (Struma). The
text of the passage is very doubtful.

Styx, 137. River in Arcadia.

Submergence of Helice and Buris, 254, 257, 259, 267, 276,
289; of Atalanta, 256; of Sidon, 256; of other cities
and nations, 267.

Subsolane (Wind), 209.

Sudd, 236 n.

Sulphur, baneful effects of, in water, 134; supposed to warm
water, 136; exists in large quantity underground, 206.

"Sulphur smell" produced by lightning, 69, 97.

Sun, size of, 20, 288; eclipse of, 35, 274, 284, 293; draws
his sustenance from the earth, 55, 198, 244; movements
of, 271 } among the constellations, 301.

Superstition, 271.

Surrentum, 221. Town on promontory in Campania.

Syracuse, 12, 142.

Syria, 138, 288.

Tempe, 137. Vale or gorge in Thessaly; see Pencils.
Temperature of atmosphere, 60, 183, 184; of various waters,

136.

Tension, effects of, 56, 58.
Tentyra, 172. Island in the Nile (Denderah), not far from

Thebes.
a Thales, 124, 125, 174, 233. Of Miletus; may be considered

the father of Greek philosophy, 636-546 B.C.
Thebes, 257. Capital of Boeotia. There was a more ancient

city of the same name in Upper Egypt on whose site are

the modern Luxor, Karnak, etc.
a Theophrastus 122 (3), 129, 138, 139, 141, 172,240,303.

Of Lesbos, favourite pupil and successor of Aristotle,

head of Peripatetic school, 322-287 B.C.
Therasia and There (Thera), 252. Small volcanic islands in

the group called Sporades, S. of Cyclades.
Thessaly, 137, 257.

Thrace and Thracians, 5, 161, 173, 254.
a Thucydides, 256, 258.
Thunderings, 62, 67 ; different kinds of, 75 ; causes of, 98.



INDEX 367

Tiberius Caesar, 41.

Tigris, 142, 235.

Time, wasting influence of, 238, 253 ; fleetingness of, 268.

Trade to Atlantic ports, 175.

Transmutation of the elements, 120, 121.

Troglodytes, 173. Cave-dwellers, specially applied to tribes

on W. of Red Sea.
Tuscans ; see Etruscans.
Tyre and Tyrian, 27, 224, 225.

Unity or continuity, defined, 53.

Universe, denned, 54; impetuous whirl of, 273; ceaseless
revolution of, 281, 294, 299 ; a harmony of discords, 301.

Vacuum, non-existent in nature, 128.

Vadimonian (Lake), 139. In Etruria, not far from the Tiber,

the Lago di Bassano, now dried up.
a Vagellius, 227. Name unknown, probably corrupt.

Valerius Asiaticus, 74. Consul, for the second time, in 46.
a Varro, 209 (2). Famous grammarian, antiquarian, etc., 116-

28 B.C.

Venus, the planet, 284.
Vice, conquest of, leads to highest happiness, 5 ; continued

progress of, 46, 187, 306, 307.

a Virgil, 28, 35, 114, 142, 165, 209, 241, 253, 258.
Virginius, 221. Consul 63.
Vitellius, 1 60. Name doubtful; may refer to father of

Emperor Vitellius, who flourished under Caligula and

Claudius, being consul in 34.
Volcanic eruptions, 73, 74, 77, 252.
Vopiscus, 303. Consul 60.
Vultur, 209. Mountain on borders of Apulia.
Vulturnus (Wind), 209.

Wars, denunciation of, 213, 214.

Water, forms of, 114, 115, 233; transformed into air, 120;
formed from earth, 120; as one of the four elements,
124; Thales opinions on, 124, 231 ; underground sources
of, 126, 233, 234, 235 ; various tastes of, 133 ; petrifying
powers of, 133; varying temperatures of, 136; artificial
heating of, 136 ; baneful kinds of, 137 ; dyeing properties
of some kinds of, 137; varying densities of, 138;
supposed physiological effects of some, 140; in mines,
154; produces animal and plant life, 197; as the cause
of earthquakes, 231, 233, 234.



3 68 PHYSICAL SCIENCE

Watergalls and sun-dogs, 33.

Weather indications, n, 14, 15, 28, 37, 39, 75, 181, 275,
302, 303.

Wells and their water-supply, 118, 123, 128; warm winter
temperature of, 176, 241.

Whirlwinds, 204, 275, 276, 278, 279, 280, 281, 282.

Will, freedom of the, 85, 86.

Wind, definition of, 193 ; Democritus view of origin of, 194 ;
origin of, 196, 200, 203, 204; within the earth, 205,
206, 239, 243, 244; number and names of the winds,
208-212 ; teleological design of, 212, 216 ; misuse of, by
man, 216; beneficial influences of, 216; disruptive
energy of, 252.

Winds, 208-211. The following are specified: Africus,
Aquilo, Argestes, Atabulus, Auster, A^Aiwr^ ( = Subso-
lane), Boreas, Cataegis, Circius, Corus, Etesian, Euronotus,
Eurus, Favonius, lapygian, Kcu/aas, Libonotus, Libyan,
Notus, Scironian, Septemtrio, Subsolane, Thracias, Vul-
turnus, Zephyrus.

Wine, frozen by lightning, 79, 97.

World, revolution of, 20.

a Zeno, 291. Native of Cyprus, founder of the Stoic philosophy,

lived between middle of fourth and third centuries B.C.
Zephyrus (Wind), 208.
Zodiac, 285, 291, 296.



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