Seneca, Naturales Quaestiones

PREFACE

LUCILIUS, my much esteemed friend While a great i
gulf separates philosophy from the other learned
arts, there is to my mind an equally wide gulf in
philosophy itself between the portion which relates
to human conduct and that which deals with the
nature and power of heaven. The latter is more
exalted and more speculative, it allows itself wide
liberty. It is not satisfied with mere observation,
it surmises that there is a greater and fairer realm
placed by nature beyond human sight. Between
these two divisions of philosophy, in short, there is
as wide a gulf as between their subjects, God and
man.

The one teaches us what should be done 2
on earth ; 1 the other, what is done in heaven.
The one dispels our errors and flashes a light by
which to thread the mazes of life ; the other far
transcends this gloom in which we grope, rescues
us from the darkness, and leads us to the very
source of light itself. For myself, I am grate
ful to nature, not so much when I see her on the
side that is open to the world, as when I am per
mitted to enter her shrine. Then one may seek to
know of what stuff the universe is made, who is its
author or guardian, what is the nature of God. Is

1 In other words, the principles of human conduct.
3



4 PHYSICAL SCIENCE BK. i

He wholly absorbed in Himself, or does He some
times regard us ? does He do something daily, or
has He done once for all ? is He a portion of the
world, or the whole world ? may He issue new
decrees even to-day and thus modify the laws of
fate, or is it an infringement of His majesty and an
acknowledgment of error to alter what has once been made ? for surely the same must always please
Him who can be pleased only with what is best.
Nor yet withal is His freedom or power diminished,
for He is a law unto Himself.

Life would have been a useless gift, were I not
admitted to the study of such themes. What
cause for joy would it be to be set merely in
the number of those who live ? In order to digest
food and drink ? To repair a diseased, enfeebled
body, that would perish unless it were continually
refilled, and thus lead the life of a sick man s
attendant? To fear death, to which our very
birth destines us ? Away with the priceless boon !

4 Life is not worth the heat and the sweat. How
despicable a creature is man, unless he rise above
the earth ! What great thing can we do as long as
we have to wrestle with our passions ? Even if we
prevail, we but conquer monsters. What cause
have we to esteem ourselves because we are not
quite so bad as the very worst ? I can see no great
reason for self-satisfaction because one s strength is
rather above the average of those in the same
hospital. You are still far from good health and
vigour. Or, again, you have escaped vices of soul,
the hypocrite s brow, the flatterer s speech fashioned
to serve another s will, the dissembler s heart, the
miser s spirit, which robs all, but yet mortifies itself.
You are a prey neither to luxury, which loses basely



PREF. DIVINE PHILOSOPHY 5

and repairs its losses still more basely ; nor to
ambition, which leads to place of worth only by 5
unworthy means. But yet you have accomplished
nothing. You have escaped many perils, but not
yet [that of] self! The virtue we aim at raises to
a splendid eminence ; not so much because escape
from vice is in itself a blessed thing, but rather
because the soul is emancipated, prepared for the
knowledge of heavenly things, and rendered worthy
of entering into communion with God.

The full consummation of human felicity is
attained when, all vice trampled under foot, the soul
seeks the heights and reaches the inner recesses of
nature. What joy then to roam through the very
stars, to look down with derision on the gilded
saloons of the rich and the whole earth with its store
of gold ! Gold, did I say ? Yes, all the gold the
earth ever produced and sent into currency, and all
that she keeps hidden in secret to glut the avarice of
posterity. Only when one has surveyed the whole 6
universe can one truly despise grand colonnades,
ceilings glittering with ivory, trim groves and cooling
streams transported into wealthy mansions. From
above, one can now look down upon this narrow
world, covered for the most part by sea, and, even
where it rises above the sea, an ugly waste either
parched or frozen. The philosopher says to himself :
Is this the plot that so many tribes portion out by
fire and sword? How ludicrous are their frontiers !
The Dacian must not pass the lower Danube ; 7
the Strymon must shut off the Thracians ; the
Euphrates must be the barrier of the Parthians ;
the Danube must form the boundary between Sar-
matian and Roman ; the Rhine must set a limit
to Germany ; the Pyrenees must raise their chain



6 PHYSICAL SCIENCE BK. i

between Gallic and Spanish provinces ; between
Egypt and Ethiopia a desert of barren sands must
stretch ! Why, if ants are ever endowed with human
intelligence, will not they in like manner portion
out a threshing-floor into many provinces ?
s But when you rise to what is truly great, then, as
often as you see armies marching forth with floating
banners, and the cavalry now scouting in front, now
massed on the flanks, as if some great design were
toward, you will pleasantly remark :

The black swarm is hurrying through the plains.

That host is a throng of ants, its evolutions are
in a back garden. In what do we excel the ants,
save in the measure of the puny little body ? That
is a mere point in which you sail, and war, and dis
pose your kingdoms. Your kingdoms are lilliputian
even when they stretch from Ocean to Ocean.

9 Only on high are the domains spacious ; to their
possession the mind is admitted, provided always
that it bring with it no taint of the body, but wipe
off all stain and pass forth like an armed man,
lightly equipped, nimble, modest in his wants.
When the soul reaches those regions, it receives
nourishment and growth ; as if freed from the
shackles of earth, it returns to the true source of its

10 being. A proof of its divine origin is furnished
by the pleasure it derives from what is divine ; here
it feels itself at home, not in a strange land.
Without alarm it views the setting of the stars and
their rising, and the mazy orbits of the heavenly
bodies that yet move all in unison. It notes when
each star first shows its light on earth, when it
attains its meridian height, observes its orbit and
the limits of its descent. An interested spectator, it






PREF. NATURE OF DEITY ^

examines and investigates every detail. And why
should it not ? It feels that they are akin to itself.
Then contempt for the narrow limits of its former n
dwelling succeeds. For what after all is the space
that lies from India to the farthest shores of Spain ?
A few days journey if a prosperous wind waft the
vessel. But that heavenly region affords a route
during full thirty years to the swiftest of the planets,
rushing with untiring velocity, never once halting.

Here at last the soul comes to learn what it has
long sought, it begins to know God. But what is 12
God ? The universal intelligence. What is God,
did I say ? All that you see and all that you
cannot see. His greatness exceeds the bounds of
thought. Render Him His true greatness and He
is all in all, He is at once within and without His
works. What, then, is the difference between the
divine nature and the human ? In us the better 13
part is spirit, in Him there is nothing except spirit.
He is wholly reason : though mortal eyes are so
sealed by error that men believe this frame of things
to be but a fortuitous concourse of atoms, the sport of
chance. And yet than this universe could aught be
fairer, more carefully adjusted, more consistent in
plan ? But men will have it that it is tossed about
at random in the confusion of thunder, cloud, and
storm, and the other forces by which the earth and
its purlieus are haunted.

Nor is this merely the madness of vulgar error ;
even the philosophers are tainted by it. Men 14
there are who think that they themselves have a
mind, one, too, that foresees and orders events
in detail whether relating to themselves or to
others. But this frame of things, in which we
men along with the rest of creation are set, they



8 PHYSICAL SCIENCE BK. i

deem void of counsel, hurried hither and thither at
random ; or at best, nature, they suppose, does not
know what her own aim is. How profitable then,
think you, will it be to ascertain the truth on such
questions and exactly to define each position ! For
example, what is the extent of the power of God ?
Does He create matter or does He employ
matter already given ? Does the pre-existing
archetype give shape to matter, or does the matter
determine the shape ? Can God perform anything
He wishes, or does material fail Him in many
15 cases, just as a great artist often produces inferior
work, not through any defect in his art, but because
the material on which it is exercised is refractory ?
To search into such things, to learn them, to medi
tate upon them why, is it not in effect to transcend
the limits of mortality and to be enrolled a citizen
of a higher state? What good will it do you,
you ask. Well, if nothing else, I shall, at any rate,
know that measured by divine standard all earthly
things are mean. But of this more anon.



To come now to my purpose listen to the explana
tion offered by Natural Philosophy concerning the
Fires which the atmosphere drives athwart. Their
oblique course and amazing velocity furnish proof
that they are thrust out with great violence. Evi
dently they do not come forth of themselves, they
are shot out. There are many different forms of
them. A certain kind of them Aristotle calls a She-
Goat. If you ask me why, I must retort by asking
you first to explain why they are also called Kids.



i METEORS 9

It will, perhaps, be more to the purpose not to 2
cross-examine one another with questions such as :
What does such and such an author say ? Answer
me. Better examine the cause of the phenomenon
itself than form surmises as to why Aristotle has
applied the name She-Goat to a ball of fire. This
was the shape of the one as big as the moon that
appeared when Paulus was engaged in the war
against Perseus. In our own days we have more
than once seen a huge ball-shaped flame which
broke up in the very middle of its course. We 3
saw a similar portent about the time of the death
of the late Emperor Augustus. We again saw one
when Sejanus was executed. A warning of the
same kind preceded the death of Germanicus.

You may, perhaps, exclaim : Are you then so
benighted as to suppose that the gods send out
previous intimation of the death of great men ? Do
you imagine that anything on earth is so great
that the Universe should perceive its loss ? That
question must be reserved for another season. We
shall then see whether a fixed succession is observed
in all events, and whether one event is so bound up
with another that what precedes is either cause or
at least token of what follows. We shall then 4
see, too, whether the gods trouble themselves about
human concerns, and whether the mere series of
events reveals by unmistakable signs what its effects
must be. Meantime, I venture the opinion that
fires of the class referred to are produced by violent
friction of the atmosphere. The pressure inclines
toward one or other side, and as there is no yielding
there, an internal struggle ensues. From violent
action of this kind arise the different varieties of
fires beams, balls, torches, and gleams. When the



ID PHYSICAL SCIENCE BK. i

shock is less severe, and the atmosphere is merely
grazed, as it were, smaller lights are emitted,

And the flying stars drag their hairy tail.

5 Then their thin fires mark a slender path, which they
prolong across the sky. For that reason no night is
without sights of the kind ; no great movement of
the atmosphere is required to produce them. In
fact, to put it shortly, they are due to the very same
cause as thunderbolts, only they require less force.

Clouds that encounter each other with little force
cause flashes of lightning ; if impelled by greater

6 violence, thunderbolts. Aristotle offers the following
explanation : The earth gives forth many different
exhalations, some moist, some dry, some cold, some
containing the seeds of fire. And little wonder if the
earth s evaporation is of all varied kinds. Why,
even in the heavens the colour of objects does not
show uniform ; the red of the Dog-star is brighter,

7 that of Mars duller ; Jupiter has no red, his sheen
is prolonged into pure light. Well, in the great
abundance of minute bodies emitted by the earth
and driven up to the higher regions, of necessity
some of the elements that reach the clouds furnish
material for fires. They do not require any collision
in order to burn, the breath of the sun s rays is
sufficient to kindle them. So with us, shavings

8 sprinkled with sulphur catch fire at some distance.
Probably, therefore, tinder of this kind gathering
within the clouds is easily kindled ; greater or less
fires are produced just as there has been more or
less substance in the elements.

On the other hand, to suppose either that
actual stars fall or leap across the sky, or that
some portion of them is taken away or pared off,



i THEIR PROGNOSTICATIONS n

is sheer folly. If this had been so, they would 9
ere this have disappeared. For there is not a
single night on which there is not a very large
number of stars that seem to break up as they
pass across the sky. Yet they are all found again
in their wonted places : each one maintains its size
unimpaired. It follows, therefore, that the fires
referred to have their origin below the stars, and
that, being without solid foundation on fixed abode,
they quickly perish. Why, then, you ask, do they
not cross the sky by day as well as by night ? 10
The next thing you will say will be that there are
no stars by day because they are not visible !
The stars are, of course, there, but obscured by
the sun s brightness. Similarly, meteor fires like
torches cross the sky by day too, but they are
hidden by the brightness of the daylight. If,
as sometimes happens, a burst of light shoots out
strong enough to assert its brilliance even in the
face of day, then they do become visible. In fact, n
our own age has more than once seen torches by
day, some rushing from east to west, others from
west to east.

Sailors consider it a sign of storm when there
are many shooting stars. If their appearance
really is a sign of wind, they must occur in the
quarter where wind is found, in other words,
in the atmosphere which lies between the earth
and the moon. In violent storms at sea there
sometimes appear, as it were, stars settling on
the sails. The sailors who are in jeopardy then
suppose that they are being aided by the power of 12
Castor and Pollux. They have really ground for
better hope in this appearance, because it makes
plain that the storm is breaking, and the wind



12 PHYSICAL SCIENCE BK. i

falling. Otherwise the fires would flit about without
settling. When Gylippus was on the voyage to
Syracuse, a star appeared, resting on the very tip
of his lance. In the camp of the Romans at times
pikes appeared to be on fire, no doubt because fires
of this kind glided down on to them : these fires are

*3 often wont to strike animals and trees, just like
thunderbolts. If, however, they are discharged
with less force, they merely glide down and settle,
and do not inflict stroke or wound. Again, some
are forced out from among clouds, others come from
a clear sky, if the atmosphere has got into a condi
tion to emit fire. In like manner, it occasionally
thunders with a clear sky, and from the same cause
as with a cloudy one, the atmosphere undergoing
internal collision. Even when the air is compara
tively clear and dry, it may become condensed, and
form bodies similar to clouds, the clashing of which

14 causes the sound of the thunder. From time to
time, therefore, arise meteors like beams and like
shields, and the semblance of vast fires over the
sky, if a force similar in kind but greater in degree
encounter suitable material.



II

LET us now see how the brightness is produced
that sometimes envelops the heavenly bodies.
History has put on record that, on the day of the
late Emperor Augustus entrance into Rome on
his return from Apollonia, a parti -coloured circle,
such as is wont to be seen in a rainbow, appeared
round the sun. The Greeks call this a Halo ;
our most appropriate name for it is a Crown.



ii HALO 13

Let me explain how it is formed. When a stone 2
is thrown into a pond, the water is observed to
part in numerous circles, which, very narrow at
first, gradually widen out more and more until
the impulse disappears, lost in the surface of the
smooth water beyond. Let us suppose something
of the same kind to occur in the atmosphere.
When condensed it is capable of receiving an im
pact : the light of sun, moon, or any heavenly body
encountering it forces it to recede in the form of
circles. Moisture, be it observed, and air, and
everything else that takes shape from a blow, is
driven into the same form as that possessed by the
object that strikes it. Now every kind of light is 3
round. Therefore, the air when struck by light will
assume this form. Accordingly the Greeks gave
the name Threshing-floor (i.e. Halo) to a brightness
of this kind, because spaces set apart for threshing
corn were, as a rule, round.

Be the better name threshing-floors, or be it
crowns, there is no reason to suppose that they
are formed in the neighbourhood of the heavenly
bodies. They are a very long distance from
them, though as seen from the earth they seem
to touch and encircle them. In reality such an 4
image is formed not very far from the earth, but
the wonted frailty of human vision is deceptive,
and we imagine the ring is formed close round the
heavenly body itself. But no such thing could
possibly occur in the neighbourhood of the sun and
stars, as there is nothing but thin ether there. It
is only when bodies have become rough and dense
that shape can be impressed upon them. In subtle
bodies there is no point on which form can lay hold
or to which it can adhere. A phenomenon of the



i 4 PHYSICAL SCIENCE BK. i

same nature as the halo may often be witnessed
in baths, because the atmosphere is thick and dark :
it is most frequent when the wind is in the south,
when the air is heaviest and most dense.

5 Halos sometimes are dissolved gradually and
fade away, sometimes they are broken up on
one side. In the latter case seafaring men look
for wind in the direction in which the circle of
the crown has been broken. If the parting is on
the north, there will be a north wind, if on the
west, zephyrs will follow. This is a proof that
these crowns are formed in the region of the sky
in which the winds are usually formed. The
upper regions of air have no crowns because they

6 have no winds either. An additional proof of the
connection of winds and halos is afforded by the
fact that the halo is never formed unless the atmo
sphere is at rest, and the wind, as it were, inactive.
Under other circumstances it is not usually observed.

The atmosphere when it is at rest may be
fashioned to any pattern by being driven or drawn in
any direction. But when it is in motion, light cannot
even strike it. It takes no shape and offers no
resistance, because the part first affected is always

7 dissipated by the motion. Therefore it is that no
heavenly body can ever be surrounded by a figure of
the kind referred to unless w r hen the atmosphere is
dense and motionless, and so preserves the ray of
round light that strikes upon it. Nor is it without
good reason. Recollect the analogy mentioned a
little ago. A pebble thrown into a pond or lake or
any other circumscribed piece of water produces
innumerable circles ; but it has not the same effect
if thrown into a river. And why so ? Because in
the latter case the water as it hurries on prevents



ITS CAUSE 15



the formation of any definite figure. So in the atmo- 8
sphere the same thing happens ; when it is stationary,
it may receive a pattern ; when it rushes in rapid
motion, it evades all control, warding off every
blow and every form as it approaches. When these
crowns, of which I have spoken, have disappeared
uniformly on all sides, and vanished in their own
tracks, it is an indication of equilibrium in the atmo
sphere : there is perfect quietness and you may then 9
look out for rain. When they break up at one side,
it means wind in that quarter. If they burst at
several points, a storm is brewing. The reason of
this may be gathered from the explanations I have
now given. If the ring fade all round, it is evident
that the atmosphere is equable, and therefore calm.
But if it is broken through on one side, evidently there
must be an inclination of the air in that direction :
hence that quarter will produce wind. But when the
halo is rent and torn on all sides, plainly an attack is
being made on it from several quarters at once, and
a disquieted atmosphere is assailing it on this side
and on that. So this disturbance of the heavens, 10
the repeated effort and striving in all directions,
betokens evidently that a storm is coming up with
sudden shiftings of the wind.

These crowns may be observed generally by
night round the moon and other stars, but very
seldom by day ; in fact, so rarely in the latter case,
that certain of the Greeks have denied that they
appear at all by day. But history proves that
they do. The cause of the infrequency of their
appearance by day is that the sun s light is stronger
then, and the atmosphere itself when stirred and
warmed by it is less dense. The moon s power, on
the other hand, is feebler, and is therefore more



16 PHYSICAL SCIENCE BK. j

ii easily resisted by the surrounding air. The rest of
the heavenly bodies are equally weak, and unable
by their own force to burst through the atmosphere.
So their shape is impressed and retained in the
more solid and less yielding medium. For, in order
to produce the phenomenon, the atmosphere must
neither be so thick as to exclude or dissipate the
light that streams in on it, nor yet so thin and rare as
to furnish no hold to the rays that fall upon it. This
particular consistency is obtained at night : the
sluggish air is at that time struck with the faint light
from moon or stars without violence or rudeness,
and, being thicker than it is wont to be by day, is
tinged thereby.

Ill

1 ON the contrary, the Rainbow does not occur by
night, except on very rare occasions, inasmuch as
the moon has not sufficient strength to pierce the
clouds and suffuse them with hues such as
they receive from the brilliant light of the sun.
The shape and varied colours of the rainbow are
due to the peculiarities of different kinds of clouds.
Some parts of the clouds are swollen, others
hollow ; some are too dense to transmit sunlight,

2 others too rare to exclude it. This difference in
consistency causes alternations of light and shade,
and produces that marvellous variety presented by
the rainbow. Another explanation is offered in
instances like the following : When a pipe bursts
anywhere, the water is observed to be forced by
pressure through the small opening ; the drops
seen against a slanting sun reproduce the appear
ance of the rainbow. Again, if you will at any



in RAINBOW 17

time watch a fuller at work, you will observe the
same appearance : when he has filled his mouth
with water and spirts it lightly on the clothes
stretched on pegs, the air thus besprinkled ex
hibits plainly the various colours that shine in
the bow. One cannot doubt that the reason of 3
this lies in the moisture. For a rainbow never
occurs except when there are clouds about.

Let us inquire how it is produced. Some
authorities say that there are certain drops of
water that transmit light, while some are too com
pact to be translucent. Thus the brightness is the
effect of the former ; the shadow, of the latter ;
by the intermingling of the two is formed the
rainbow, part of which is bright, to wit, that which
admits sunlight, part darker, namely, that which
has shut out the light and cast a shadow from itself
over the objects nearest it. Others again deny that 4
this is so. Shade and light, they say, might be the
cause if the rainbow had only two colours, and
thus was made up of light and shade.

But now, though there gleam a thousand diverse hues,
Their changes withal elude the eyes that behold.
The hues that touch seem actually one, yet the edges are quite
different.

In it sight detects something that is red, something
that is orange, something that is blue ; and there
are other colours too, laid on in finest lines just
like a skilful painting, so that, as the poet remarks
above, it is impossible to discover whether the
colours differ from one another until the last of
them is compared with the first. The junction of 5
colour with colour deceives the sight : with such
marvellous skill does nature starting from what is
like end in what is totally unlike. What good, then,

c



1 8 PHYSICAL SCIENCE BK. i



do the two alleged colours, light and shade, do in
a case of this kind, when the presence of an endless
variety must be accounted for ? Again,

certain authorities are of opinion that the following
is the method of formation of the rainbow : In the
quarter of the sky where rain is falling, they say,
the drops of falling rain are so many mirrors ;
from each mirror, therefore, is reflected an image
of the sun. By and by, many, in fact, countless,
images, descending and crossing abruptly, are all
blended together. Therefore the rainbow is just a
blending of a great number of images of the sun.

6 They appeal to the following argument in proof of
this : On a clear day, say they, set out a thousand
basins, and they will all contain images of the
sun. Or arrange single drops of water on single
leaves ; they will each have an image of the sun.
On the other hand, an immense pond will have no
more than one image. Why so ? Just because
every smooth surface that is fenced off, and sur
rounded by its own boundaries, is a mirror. Again,
divide a pond of very large size into several small
ponds by inserting partition walls ; it will show as
many images of the sun as it has divisions. Leave
it as it was, spreading out to its full extent, and it

7 will show but one reflection of him. The small
extent of the liquid or pond makes no manner of
difference. If the surface is circumscribed, it forms
a mirror. Well then, those countless drops, which
are carried down by a falling shower, are so many
mirrors, and contain so many reflections of the sun.
To an observer right in front of them they
present the appearance of being mixed up : the
intervals which part them from each other are not
distinguished, their mere distance from the observer



in ARISTOTLE S EXPLANATION 19

prevents discrimination of them. By and by
instead of individual drops there is seen a single
blurred mass that contains them all.

Aristotle agrees with this opinion. His words

are : Beams of light are reflected by sight

from every smooth surface. Now, nothing is 8

smoother than water and air. Therefore, our

sight is reflected back on us from thick air.

Indeed, where the vision is dull and feeble,

the slightest stroke of air checks it. Some

people suffer from an affection which causes

them to think that they are meeting their own

image, and they see everywhere the reflection of

themselves. And why ? Because the power of

their eyes is so weak that it cannot overcome the

resistance of even the nearest layer of the

atmosphere. What dense air effects in ordinary

cases, any kind of air is sufficient to effect in

the cases referred to by Aristotle. For whatever

the nature of the air, it is strong enough to defeat

i weak sight. Now, much more is our vision

reflected upon us by water because it is denser

j and cannot be pierced ; it absolutely stops the

rays from our eyes, and turns them back to the

i source whence they proceeded. Well then, 9

i when there are numerous raindrops, they are

ljust so many mirrors. But on account of their

smallness they express the sun s colour without

distinct shape. By and by when the same colour

is reflected in the countless drops that fall without

I intermission, it begins to take on the appearance

I not of numerous images with intervals between, but

of a single, long, uninterrupted image.

But how, you may object, can you tell me that there
are many thousands of images there, where I can



20 PHYSICAL SCIENCE BK. i



10 see none at all ? Besides, as there is but one colour
in the sun, why are there different colours in the
reflections of him ? These objections which you
have put forward, as well as others that no less call
for refutation, I will endeavour to refute. And let
me say, first of all, that nothing is more deceptive
than our eyesight, not merely in objects whose
careful examination is prevented by distance in
position, 1 but even in objects seen close at hand.
An oar, though quite whole, presents the appear
ance of being broken when seen in clear shallow
water. Apples seen through glass appear much

11 larger than they really are. In long colonnades,
pillars set at intervals present an apparently un
broken continuity of line. Or go back to the case
of the sun himself ; his orb, which reason proves
to be larger than the whole earth, is so contracted
by human sight that some of the philosophers have
maintained that it is only a foot in diameter. He
is, we know, the swiftest of all luminaries, yet none
of us can see him move ; nor should we believe
that he does advance, were it not evident from time
to time that he has advanced. The world itself
glides on with headlong speed ; within an instant of
time it unfolds its risings and its settings, yet none

12 of us is aware of its movement. What cause, then,
is there for wonder if our eyesight cannot separate
the drops of the rain showers, and loses the dis
tinction of the images on account of the vast
distance at which they are beheld ? At any rate
no one can doubt this, that the rainbow is a
reflection of the sun, formed in a hollow cloud full
of moisture. This is made plain from the simple fact
that the image is never seen except opposite the sun,

1 The received text gives "diversity of colours."



in COLOUR OF RAINBOW 21

high up or low down, in inverse relation, just as he
sinks or elevates his course. When he descends,
it is higher ; when he is high in the heavens, it is
more sunken. A cloud of the required kind is 13
often at the side of the sun without producing a
rainbow, because it does not catch his image
straight in front.

As to the variegation in colour, it is due
simply to its double source, derived partly from
the sun, partly from the moist cloud. The mois
ture produces lines now blue, now green, now
purple-like, and orange or red the two shades,
dull and bright, combining to produce this diversity.
So also, a purple garment does not always come 14
out in exactly the same tint from the same dye.
Differences depend upon the length of time it has
been steeped, the consistency and the amount of
moisture in the dye it has imbibed : it may be
dipped and boiled more than once, or it may have re
ceived only one immersion. In like manner then,
when there are the two elements, sun and cloud,
in other words, object and mirror, it is little wonder
that as many varieties of colour are generated as can
be produced from them in higher or lower tone in
countless different categories. For example, there 15
is one colour that proceeds from the light of fire,
another from a light that is duller and less violent
than fire. In other details concerning the rainbow
the method of inquiry is full of uncertainty ; there
is nothing concrete to lay hold upon, and conjecture
must be ventured in every direction. But in this
question of its origin doubt is precluded ; for it is
evident that the causes of the rainbow are two in
number, sun and cloud. The bow never appears
when the sky is clear, and never when it is so



22 PHYSICAL SCIENCE BK. i

cloudy as to hide the sun. It must, therefore,
unquestionably arise from these, failing either of
which it cannot come into being.



IV

1 A FURTHER consideration must be mentioned, which
is just as manifest as the preceding, to prove
that the reflection is given back after the fashion
of a mirror ; it is never given back save from
straight opposite to the sun, that is, 1 unless on
one side stands the object to be reflected, and on the
other the mirror that reveals it. Proofs are adduced
by the mathematicians that are not merely convinc
ing but that compel belief of this. Nor can doubt
be left in any mind that the rainbow is an image of
the sun, imperfectly reflected owing to the defective

2 shape of the mirror. But meantime let us
recall other proofs that may, so to speak, be picked
up in the street without any reference to mathe
matics. Among the proofs of this origin of the bow
I place the extreme rapidity of its emergence. In
a single moment the huge form with its thousand
lines is inwoven in the texture of the heavens, and
just as rapidly does it fade. Now, nothing is
returned so quickly as an image from a mirror.
The mirror does not create anything, it merely

5 reveals it. Artemidorus of Parium tells us further
even the kind of cloud required to reflect such an
image of the sun. If you make a concave mirror,
he says, that is, one resembling half of a ball cut
through the middle, and take your stand outside
the centre, then those who stand beside you will

1 In a writer less prone to repetition the words to the end of the sentence
would seem the insertion of a copyist.



iv MIRROR AND IMAGE 23

appear in the reflection inverted and nearer to you
than to the mirror. The very same thing, accord- 4
ing to him, takes place when we look at a round
hollow cloud from the side : the image of the
sun detaches itself from the cloud, and is nearer
us and more turned in our direction. Therefore
the red colour is from the sun, the dark blue is
from the cloud : the other hues are produced by a
blending of these two.



BUT there are arguments on the other side. About
mirrors there are two opinions ; some people think
that only phantoms are seen in them ; in other
words, the shape of our bodies, an emanation sepa
rated from our bodies. Others, however, affirm
that images do not exist in the mirror, but that it is
the very bodies that are seen, the eyesight being
bent back and reflected on itself again. Now, the
point is not how do we see whatever it is we see :
the question is, how the image should resemble the
original in the cloud as in a mirror. 1 Could any
thing be more unlike than the sun and a rainbow in
which neither the colour nor the shape nor the size
of the sun is to be seen ? A bow is far larger
and, in the bright part, far redder than the sun : in
the other colours, too, it is different from him.
Besides, when you insist on comparing a mirror to
the atmosphere (i.e. as embodied in a cloud), you
must show me in the latter the same smoothness of
texture, the same levelness of surface, the same

1 The reading of the MSS. is admittedly corrupt. I have followed Ruhkopf s
conjecture, though without conviction. The argument seems to require dissimi-
lis unlike, or non similis (cf. c. v. 13), instead of similis like ("re
semble " in the text) : in that case the meaning would be : how an image
unlike the original ought to be reflected from the cloud as from a mirror.
I



24 PHYSICAL SCIENCE BK. i

brightness as in the former. But surely no clouds
resemble mirrors to this extent. We often pass
through the middle of clouds without seeing our
selves in them. People who climb to the tops of

3 mountains look down on cloud, but cannot make
out their reflection in it. True enough,
but it is separate drops that are separate mirrors,
says my opponent. Admitted. Still, I deny
that a cloud consists of fully formed drops. It
no doubt contains the elements from which the
drops are formed, but not as drops. Clouds do
not contain even water, but only the material to
form water. Granting, for the sake of argument,
that there are countless drops in the clouds and
that they can reflect an object, yet they do not
all produce one and the same reflection, but each

4 its own. Further, you may join mirrors to one
another, but they will not unite to form a single
reflection : each portion will enclose a likeness of the
object. Some mirrors are composed of a large number
of very small parts. Set before them one man and a
whole people is reflected, each portion producing an
image of its own. The portions of the mirror thus
united and placed side by side none the less keep
their images separate, and out of one man make

5 a crowd. But they do not blend in one that
troop ; they separate and distinguish the individual
faces. Now, a rainbow is bounded by a single
outline, the whole presents but one representation.

Well, but, says our opponent, is not the water
that is scattered from a burst pipe, or that is
tossed up by the oar, wont to exhibit something
similar to these colours that are seen in the bow ?
True, but not for the reason which you wish to
bring out, to wit, that each single droplet receives



v COLOUR EFFECTS 25

an image of the sun. As a matter of fact, the 6
drops fall too quickly to be able to form such an
image. The medium must be stationary in order to
receive the impression of what is to be reproduced.

How, then, it may be asked, does it come about ?
The drops, I reply, receive the colour, but not the
image of the sun. Besides, as Nero Caesar says
very elegantly :

The neck of Venus dove glitters as the bird tosses its head,

and so the neck of the peacock shines with varied
colours as often as it is turned hither and thither.
Are we, therefore, to say that feathers of this kind, 7
whose every turn passes into new colours, are
mirrors? Well, clouds differ in character from
mirrors no less than the birds mentioned, and as
chameleons and the other animals whose colour
changes. In the latter case the cause is sometimes
subjective : the creatures when inflamed with anger
or passion vary their hue through the suffusion of
moisture : at other times the position of the light,
direct or slanting, gives the colour its particular hue.
What resemblance, I say, is there between mirrors 8
and clouds? Whereas those are not translucent,
these transmit light. Those are dense and com
pact, these are rare. Mirrors are of uniform material
throughout, clouds are made up of various ele
ments brought together at random, and therefore
are full of internal strife, and cannot long hold
together. Consider further ; at sunrise one sees a
certain portion of the sky ruddy ; at other times
one sees clouds of fiery red. This particular colour
is received by the clouds from encountering the sun:
what, then, is there to prevent the many colours of
the bow being derived by them in the same way



26 PHYSICAL SCIENCE BK. i

from him, even though they do not possess the
9 power of mirrors ? A little ago, my oppo

nent retorts, you advanced the argument that the
rainbow is always produced opposite the sun, be
cause an image could not be reflected from a mirror
unless the object were in front of it. We agree
in this point, he adds. Yes, for just as the object
whose image is to be transferred to the mirror
must be set opposite the mirror, in like manner,
in order that the clouds may be tinged by the
sun s rays, the sun must occupy a suitable posi
tion. He does not produce the same effect if
his light streams in on all sides : there must
be a proper incidence of the rays to produce
the effect. Such are the reasons alleged by

those who will have it that the rainbow is a coloured
cloud.

Posidonius and those who are of opinion that
the phenomenon is produced by reflection as from

10 a mirror, answer their arguments thus : If there
were any real colour in a bow, it would persist,
and be seen more distinctly, the nearer it is. As
it is, the image of the bow is clear only in the
distance ; it is lost as it begins to approach.
I do not agree with this argument in refutation,
though I approve the main sentiment which
it supports. And I will tell you why. The
cloud is coloured, but in such a way that the
colour cannot be seen from every point. And no
more can the cloud itself : for no one who is in it

11 can see it. What wonder, then, if its colour cannot
be seen by one to whom itself is not visible ? And
yet, although the cloud is not seen, it is there : and
so is the colour. It is, therefore, no proof of the
deceptiveness of the colour that it ceases to be



v REFLECTION 27

manifest when one approaches it. For, I repeat,
the same happens to the clouds themselves : they
are not all a sham merely because under certain
conditions they cease to be visible. Besides,

when you are told that the cloud is dyed by the sun,
it does not mean that that colour of his is mingled,
as it were, with a hard, firm, durable body, but
with a liquid unstable body that is incapable of more
than a very brief impress. Let me add that there 12
are certain artificial colours which display their
virtue at a distance. The better and richer the
Tyrian purple is, the higher up you must hold it to
display its full blaze. It does not cease to possess
its colour simply because it does not reveal its best
shade in any and every position in which it is
exhibited. I am of the same opinion as

Posidonius in holding that the bow is formed in a
cloud shaped like a hollow round mirror, whose form
is that of a section through a ball. This cannot be 13
proved without the aid of geometry : the mathe
matical proofs leave no doubt that the bow is an
image of the sun, but one that does not resemble it.
Nor, indeed, are all objects faithfully represented in
mirrors. There are some mirrors one is terrified to
let one s eyes rest upon, such is the misshapen
and distorted image they reproduce of those who
gaze upon them. They deform the likeness they
preserve withal. Some, again, there are, a glance at M
which causes great self-satisfaction in one s strength :
the arms are enormously increased, and the appear
ance of the whole body is enlarged to superhuman
proportions. There are mirrors that turn faces to
the right, and mirrors that turn them to the left,
others twist and even invert them. What wonder,
then, that a mirror of this kind should be formed in



28 PHYSICAL SCIENCE BK. i

a cloud by which a defective appearance of the sun
should be presented ?



VI

j AMONG the other arguments it must be mentioned
that a rainbow never is seen greater than a semi
circle : the higher the sun is, too, the smaller is the
bow. As our countryman Virgil says :

And deep drinks
The mighty bow,

when rain is brewing. But the threat the bow con
veys is not the same whatever the quarter it has

2 shown itself in. If it rises toward the south, it will
bring a heavy fall. The rain in that quarter, such is
its force, cannot be mastered by the strongest midday
sun. If it shine toward the west, there will be only
a dew or a light rain. If it rise in the east or there
abouts, it prognosticates fine weather. If,
however, the bow is the sun s reflection, why does
it appear of far larger size than the sun himself?
Just because there is a kind of mirror that exhibits
objects on a far larger scale than that on which
they are presented to it, increasing their form to a
portentous magnitude : and in turn there is another
kind that reduces the size. And tell me this again,
why does an image assume the form of a circle if

3 it does not answer to a circle ? You may, perhaps,
tell me why the colour of the bow is varied : why
its shape is what it is, you will not be able to tell
me except by citing some model after which it is
formed. Now, other model there is none save that
of the sun ; when you admit that the rainbow
receives its colour from him, it follows that it



vj SIZE AND SHAPE OF BOW 29

receives its shape also from him. In short, you and
I are agreed that those colours by which its quarter
of the heaven is adorned proceed from the sun.
But on one point we are not agreed : you say that
the colour is real ; I maintain that it is only
apparent. Whichever it is, real or apparent, it
comes from the sun. On your assumption its
sudden cessation cannot be explained, seeing that
all other bright lights in the sky are dispelled
gradually. Its sudden appearance and, at the same 4
time, its sudden extinction make for my contention.
For it is a peculiarity of a mirror that the reflection
in it is not built up piecemeal, but all at once comes
fully into being. Every image in it is destroyed,
too, with as great rapidity as it was formed. For to
the construction or removal of the images nothing
is required but the presentation and withdrawal of
the objects.

In the rainbow-cloud whose nature is in ques
tion, there is no proper substance or material :
there is only a sham and a likeness without
reality. Will you be convinced that this is so? 5
The proof is, the rainbow will cease if you conceal
the sun. Place another cloud, I repeat, in front of
the sun, and all the bright hues of the bow are
gone. But what is to be said, you may ask,

in explanation of the size of the bow which is con
siderably greater than that of the sun ? I have
already said that there are certain mirrors that
multiply every object they reflect. I may now add
that every object much exceeds its natural size when
seen through water. Letters, however small and
dim, are comparatively large and distinct when
seen through a glass globe filled with water.
Apples floating in a glass vessel seem more beauti-



3 o PHYSICAL SCIENCE BK. i

6 ful than they are in reality. The stars appear
bigger if seen through a cloud, because our vision
is blurred in the moisture, and cannot accurately
grasp its object. This will become plain to demon
stration if you fill a cup with water and throw a
ring into it. While the ring lies right at the bottom
its appearance is visible on the surface of the

7 water. Anything, in fact, that is seen through
moisture appears far larger than in reality it is.
What wonder that the image of the sun, being
seen in a moist cloud, should be reproduced on a
scale larger than the original, and that for the two
reasons indicated ? The cloud contains the two
elements, one like glass, which can transmit light,
and one also of the character of water ; at any rate,
if it does not just yet contain the actual water, it
is now forming it, its nature is already such as can
easily be changed into water.

VII

1 As you have mentioned glass, some one inter
poses, I can draw from this same material an
argument to confute you. Glass sticks are manu
factured, either fluted or bulging, 1 with many
corners like a club. If one of these sticks is placed
obliquely in the path of the sun s rays, it sends
back the colour which is wont to be seen in the
rainbow. This proves that there is not here an
image of the sun, but an imitation of his colour

2 from reflection. Now, in this argument there are
many points that make for my view. First of all,
it is plain that there must be some smooth surface
like a mirror to reflect the sun. Secondly, it is

1 Another reading gives " twisted."



vii PRISMATIC EFFECTS 31

plain that no colour is formed in the rod, but only
a false appearance of colour, such as I mentioned
above, which the neck of a pigeon, as it is bent
hither and thither, alternately puts on and off.
This, I say, is seen likewise in the case of a mirror,
which assumes no real colour, but only a certain
imitation of the colour of a foreign body.

Still, this one point requires explanation ; it is 3
not the sun s image that is beheld in that glass
stick, because it is not capable of expressing it
accurately. True enough it tries to reproduce the
image, because the material is smooth and suitable
for this purpose. But it fails because its shape is
unsymmetrical. If it had been suitably constructed,
it would reflect as many images of the sun as it
had faces. But since the sides are not distinctly
separated from each other, and not bright enough
to serve as mirrors, the images are only incipient,
not fully expressed ; they get confused through
being crowded together, and are reduced to the
appearance of a single band of colour.



VIII

BUT to return why does the bow not complete
the full circle in its form, but appear as only a semi
circle when stretched to the full extent of its
greatest span ? Some are of opinion that the
reason is that the sun, being much higher than the
clouds, strikes them only on the upper side. Hence
their lower parts are not touched by his light.
Receiving the sun only on one side, the clouds
reproduce only one portion of him, and this is
never more than a half. There is very little force



32 PHYSICAL SCIENCE BK. i

2 in this contention. My reason for saying so ? The
sun, even though he is on the upper side, yet
strikes, and therefore colours, the whole cloud.
How could it be otherwise ? His rays are wont
to be transmitted through the clouds and to
penetrate any density in them. Further, the proof
they advance is flatly in opposition to their main
proposition. For if the sun is higher than the
clouds, and his beams, therefore, shed only on their
upper side, the bow would never come down as far

3 as the earth. Yet it does descend to the very
ground. Besides, the bow is never seen except
opposite to, not below, the sun. The fact is, the
sun s highness or lowness does not affect the
matter : the side of the cloud that faces him is
struck by him throughout its whole extent.

Furthermore, sometimes even the setting sun
produces a rainbow ; surely at that time, being near 1
the earth, he strikes the clouds on their lower side.
And yet then, too, the bow is only a semicircle, though
the clouds receive the sunlight on their lower and

4 darker portions. The Stoics, who hold that the
light is reflected in the cloud as in a mirror, make
the cloud hollow like the section of a ball. Such a
mirror, being but part of a circle, cannot, they
think, reproduce a whole circle. I give my adherence
to the proposition, but I cannot agree to the
argument in its support. For, if the whole figure
of a circle placed opposite a concave mirror is
reproduced in it, then there can surely be nothing to
prevent the whole of a ball being seen in a semi-

5 circular mirror. Besides, we have already shown that
complete rings resembling a rainbow surround the

1 The common reading makes this adjective refer to clouds the clouds
which are near the earth.



vin SEASONS OF RAINBO W 33

sun and the moon at times. Why should the circle
be complete in the halo, but never in the rainbow ?
And then again, why should the clouds that receive
the sunlight be always hollow ones, and not some
times flat or bulging ?

Aristotle says that rainbows are formed, after the
autumnal equinox, at any hour of the day, but in
summer only either in the early part of the day, or
when the sun has begun to sink. The cause of this
is obvious. In the first place, about midday the great 6
heat of the sun dispels the clouds : he cannot be
reflected in the clouds which he breaks up. But
in the early morning and as he sinks toward the west,
his rays have less power, and can thus be resisted
and reflected by the clouds. In the second place,
the sun is not wont to form a bow except when he
faces the clouds in which it is formed. When the 7
days are shortening in autumn, his rays are always
slanting. Therefore, he has some clouds facing him
that he can strike, at any part of the day, even at
the hour at which he attains his meridian height.
But in the summer season he sails right overhead.
Therefore, in the great altitude of his midday
course, he looks down on the earth too directly to
encounter any clouds. He has them at that period
all beneath him.



IX

I MUST now go on to speak of Streaks (watergalls, i
sun-dogs), which are as bright and varied as the
rainbow, and commonly received by us as equally
indicative of rain. No great labour need be spent
in explaining them, for they are just incomplete 2
rainbows. They have the variegated appearance

D



34 PHYSICAL SCIENCE BK. i

of the bow, but none of its curve. They lie in
a straight line. They are formed near the sun,
as a rule, in a moist cloud that has begun to break
up. Thus, they have the same colour as is found
in the rainbow, but there is a difference in the
shape, due to the corresponding difference in the
clouds over which they stretch.



X

THERE is a similar variety of colours in Halos.
But there is this difference in the various pheno
mena : Halos are formed at any point in the sky,
wherever there is a heavenly body ; rainbows are
not found except opposite the sun ; streaks, only
in the neighbourhood of the sun. I may express
their difference in another way : Bisect a halo and
you have a rainbow ; make it a straight line and
you have a streak. In all three there is the same
multiplicity of colours, the scale running from dark
blue to orange. Streaks, then, are found only close
to the sun. Rainbows are all either solar or lunar.
Halos are seen with all the heavenly bodies.



XI

1 ANOTHER kind of streak is visible when thin rays
of bright light equidistant from one another are shot
out through narrow apertures in the clouds. These,
too, are a prognostication of rain. How am I to
express myself here ? What shall I call them ?
Images of the sun ? The chroniclers call them
merely suns, and have put on record that they have

2 been seen in twos and threes. The Greeks call



xi MOCK SUNS 35

them Mock Suns (parelia = beside the sun), because
they are generally seen in proximity to the sun,
and somewhat resemble the sun. They do not
give a complete reproduction of the sun, but ex
hibit only his size and shape. They are dull,
however, and languid without any of his heat.
What name are we to apply to them ? Shall I do
as Virgil did hesitating about the name, employ
the very name which causes the hesitation ?

And by what name 1 shall I call you,

Rhaetian wine? But yet you must not seek to compete with
the Falernian bins.

There is no objection to my calling these, mock
suns. They are, in fact, images of the sun formed 3
in a thick cloud close to him after the fashion of a
mirror. Some writers define a mock sun as a cloud,
round, bright, and resembling the sun. The mock
sun follows the sun, and is never left farther behind
him in his orbit than it was at its first appearance.
None of us, I suppose, is surprised at seeing a
reflection of the sun in some fountain or quiet lake.
Well, his disc may be reflected in the heavens just
as readily as on earth, if only the material is suitable
to produce the reflection.



XII

WHENEVER we wish to observe an eclipse of the
sun, we place on the ground basins filled with oil
or pitch. The thick liquid is not easily disturbed,
and therefore retains the images it receives.
Images, I may observe, cannot be seen except in a

1 He has altered Virgil s word "carmine" to "nomine" to suit his
meaning, or, as the editors say, lapsu memoriae.



36 PHYSICAL SCIENCE UK. i

liquid at rest. Then we are in the habit of noting
how the moon obstructs the sun, and by the inter
position of her body hides his, which is so much larger,
sometimes partially, if it so fall out that she only
encounter a portion of his orb, sometimes completely.
2 The latter is called a total eclipse : it quite shuts
out the light and shows us the stars ; it occurs when
the centre of the two bodies lies in the same straight
line. Now, just as the image of both sun and moon
can be seen on earth, so it is in the case of mock
suns in the atmosphere. The still air is so compact
and yet clear that it can receive the sun s likeness.
Other clouds receive it, but let it go if they are
either in motion, or thin, or black. The moving
clouds disperse it, the rare let it slip, the black and
impure do not take the impress of it, just as on
earth soiled objects do not reflect an image.



XIII

1 MOCK suns are wont to be formed in pairs and on
the same principle. There is nothing, in fact, to
prevent the formation of as many as there are clouds
suitable for exhibiting an image of the sun. Some
writers are inclined to hold that when two such
phantoms are visible, one arises directly from the
sun, the other from his image. For, to use an
illustration from common experience, when several
mirrors are so arranged that one is in sight of the
other, all reflect the same image ; but only one is
directly from the original, the rest are reflections

2 of images. The nature of the object presented to
the mirror makes no difference in the effect. What
ever it sees it reproduces. So, up on high there, if



xiii THEIR CAUSE 37

some chance has so disposed the clouds that they
face one another, one of them reflects the image of
the sun, the other the image of his image. The
clouds that produce this effect must be dense,
smooth, bright and flat, analogous in character to
the sun. All phantoms of this kind are white and
resemble so many discs of the moon, for the reason
that the sun s light that they receive and reflect
back is always oblique. If the cloud, on the con- 3
trary, is beneath the sun and too near him, his rays
dispel it : or again, if situated too far away, it does
not reflect them nor produce any image. In
ordinary experience in the same way mirrors with
drawn to a distance from us do not reproduce our
features because our sight cannot carry back to us
from them.

These suns, too to employ the name given by
the chroniclers, are an indication of rain, especially
if they have their position in a southern quarter,
from which the most heavily-charged clouds chiefly
come up. When such an image surrounds the sun
on both sides, then, if we are to believe Aratus,
a storm is brewing.

XIV

IT is now high time that I ran over the other i
varieties of celestial fires, whose forms are diverse
one from the other. Sometimes there is a shooting
star, sometimes there are glowing lights, which are
occasionally stationary, sticking to one spot, and at
times able to rush through the air. Several species
of these may be observed. There are, for example,
Bothynae (cave -like meteors) when within an
outer circle there is a blazing gulf in the sky like a



38 PHYSICAL SCIENCE BK. i

circular grotto excavated in it. Then there are
Pithitae (barrel-shaped meteors) when a vast circular
mass of fire like a cask either rushes through the

2 sky, or blazes away in one spot. There are
Ckasmata (chasms), too, when there is a subsidence
of some portion of the heavens, which sends out
hissing flame, as it were, from its hidden recesses.
There are also a great number of colours in all
these. Some are of brightest red, some of light
insubstantial flame, some of white light, some
glittering, some with a uniform glow of orange
without sparks or rays. We see, therefore,

The stars long tracks that gleam white behind.

3 These stars, for so they appear to be, dart forth
and flit across the sky, and by reason of their
extraordinary rapidity seem to leave a long trail
of fire. Our sight cannot follow their course, and
wherever their career leads we imagine the heaven
is all on fire. Such is the swiftness of their flight
that its separate portions are not distinguished
and it can be grasped only as a whole. We are
aware rather of the quarter in which the star

4 appears than of its route. It, therefore, seems to
mark its entire course with a line of continuous
fire, because the slowness of our vision fails to keep
pace with the stages of its career and sees at the
same moment the start and the finish ; as happens
in a flash of lightning, the fire seems a long train
because the meteor traverses its path rapidly and
the space through which it falls presents itself to
our eyes as a whole. But, as a matter of fact, the
fire does not extend itself all through the space

5 crossed by the meteor. Nor have such long thin
bodies strength enough for the effort. How, then,



xiv OTHER CELESTIAL FIRES 39



it may be asked, do they issue forth ? The answer
is, the fire is kindled by the friction of the atmosphere
and is urged headlong by the wind. Still, it does
not always arise from wind or friction. Some
times its origin is due to certain peculiar conditions
in the atmosphere ; for on high there are many
elements, dry and hot and earthy, among which fire
is generated. It then streams down in pursuit of
fuel to sustain it, and therefore is hurried rapidly
along. The reason for the differences of colour it
presents lies in the nature of the material set on
fire and in the degree of violence of the conflagra
tion. A falling body of this kind betokens wind,
which may be looked for in the quarter in which
the meteor has burst out.



XV

How, some one further inquires, are those bright i
gleams of light which the Greeks call Sela (lumin
osities) produced ? In many ways, people say.
They may arise from the violence of the winds,
or from the fervent heat of the upper heavens.
Fire is a very widely diffused element there, and
sometimes catches the lower regions if they are
combustible. The mere motion of the stars in
their courses may kindle fire, and convey it
to all that lies beneath them. Nay, is it not
quite possible that the atmosphere should drive up
even to the ether the germs of fire, from which may
arise a glow or burning or darting resembling a
star? Some of these gleams rush headlong like 2
shooting stars, some remain fixed in their place,
emitting light sufficient to dispel darkness and re-



40 PHYSICAL SCIENCE BK. i

instate daylight, until their fuel is used up, and they
gradually grow dimmer, and by and by, just like a
flame which is dying out, are by gradual subsidence

3 reduced to nothingness. Some of these appear in
the clouds, some above them : in such cases the
thick air nearer the earth feeds them for a long time,
but eventually forces them right up to the stars.
Certain of these last no considerable time : they
straightway dart across the sky, or are extinguished
just at their point of origin. These are called
gleams because their appearance is fitful and short
lived, though their fall is not always unattended by
injury : they have often caused as much damage as
lightning. One has seen houses struck by them,
what the Greeks call astrapoplecta 1 ( = star-struck).

4 Those that have a longer career and a stronger fire
which follows the motion of the heavens, or those
that pursue an orbit of their own, are regarded by
the Stoic philosophers as Comets : of which more
anon. Different kinds of these axtpogoniae (bearded),
lampades (torches), and cyparissiae (like cypress
trees), and all the rest of them : they have a thin
tail of fire. It is doubtful whether beams (trades]
and the rare barrel -meteors (pithitae) should be

5 placed in this category or not. Such meteors re
quire a great mass of fire, since their immense orb
sometimes surpasses in size that of the morning sun.

Among these should certainly be placed a pheno
menon of which we often read in the chronicles
the heavens appeared to be on fire. The blaze
of it is occasionally so high as to mount to the very
stars ; occasionally it is so low as to present the

6 appearance of a distant fire. In the reign of

1 The term might also mean struck by lightning. A commoner reading
gives the meaning : which, when grazed by this means, the Greeks called
plecta ( = struck).



xv SUBSTANCE AND SHADOW 41

Tiberius Caesar the fire brigade hurried off to the
relief of the colony at Ostia, supposing it to be in
flames ; during the greater part of the night there
had been a dull glow in the sky, which appeared to
proceed from a thick smoky fire. No one has any
doubt that these burnings in the heavens contain
flame as really as they display it : they have a
certain substance in them. As to those for- 7

merly discussed, I mean rainbows and halos, it is a
question whether they deceive the sight and consist
of an illusion ; or really contain what appears in
them. I and those who think with me cannot con
vince ourselves that the rainbow and halo have a
basis of any definite material in them. For we judge
that in a mirror there is nothing but a deception :
the mirror only pretends to show a foreign body.
What is revealed does not exist in the mirror. 8
Otherwise it would not come out of it, nor would it
be forthwith obscured by another image : nor would
innumerable forms now fade from it, now be received
by it. What follows, then ? That these are mere
phantoms and the insubstantial imitation of real
bodies. Indeed, in certain instances, people have so
arranged mirrors that the objects have been distorted
and degraded in the reflection. For, as I have already
said, there are some mirrors that twist the faces of
those who look into them, some that enormously
increase them until they exceed all size and propor
tions of these bodies of ours.



XVI

AT this point I wish to tell you a little story
to show you how unscrupulous lust is in seizing



42 PHYSICAL SCIENCE BK. i

every instrument that will rouse passion : so re
sourceful is it in goading to madness its own morbid
fury. There was one Hostius Quadra whose
obscenity formed a model for everything that was
lewd on the stage. He was rich and avaricious, a
very slave to his millions. He was eventually
murdered by his own slaves, but the late Emperor
Augustus considered his murder undeserving of
punishment, and as good as declared that he had

2 been justly slain. This man s lust knew no distinc
tion of sex. Among other things, he had mirrors
constructed of the kind just mentioned, that re
flected images of abnormal size, causing, for ex
ample, a finger to exceed the size of an arm in
length and thickness. He so arranged his mirrors
that he could see all his accomplices movements,
and could gloat over the imagined proportions
; i 3 of his own body. He raised a levy of scamps
like himself in all the public baths, where he chose
men of the regulation height ; this but whetted his
appetite to have his scenes of riot reproduced in
false unnatural proportions. Go to, you that say
the mirror was invented for purposes of adornment !
I could not soil my pen by recording the foul words
and deeds of that monster : he deserved to be torn
by his own jaws. To aggravate his guilt, mirrors
faced him on every side that he might be a witness of

4 his own infamy. Deeds of darkness, which lie heavy
on the conscience, the imputation of which ordinary
men will indignantly spurn, weighed so lightly with
him that he thrust them before his face, and into
his very eyes. Crimes, in faith, usually dread the
sight of themselves. Even in those lost to shame,
and exposed to every insult, the eye is still delicately
susceptible. But that beast thought his unparalleled



xvi STOR Y OF HOSTIUS Q UADRA 43

wickedness but a trifle ; he summoned his eyes to
witness it. Aye, not content with seeing his sin, he
surrounded himself with mirrors to multiply and
group his scenes of vice. Even when he could not 5
see directly, he employed the reflecting power of
the mirrors to reveal scenes of revolting and abomi
nable iniquity. The filthy blackguard left nothing 6
that could be called a deed of darkness. He had no
dread of the daylight, but complacently applauded
himself in all his bestial vice. Now, don t you
think he would have liked to have his portrait
painted in that attitude ? The ministers of public
vice draw the veil of modesty over them in part :
in fact, a house of ill-fame is in some degree shame
faced. But that brute had made an exhibition of 7
his obscenity, and presented to his own sight what
the darkest night is not deep enough to hide. I will be
out and out bad, was the monster s resolve ; my eyes
must share my lust, they must witness and super
intend ! By my art I will defeat nature s shyness : 8
nobody must imagine that I do not know what I am
about! Nature is niggardly to man, she is more
generous to the cattle. I will find means to thwart
her, and to indulge my little weakness. My lust
shall go one better than nature. I will construct a
mirrored chamber that will reflect shapes of enor
mous size. I only wish I could make the size real ; 9
but I must be content with the belief of it. My
vice must see more than it can compass, and must
rest content with wonder at its own restraint.

Away with such a fellow ! Perchance he met a
speedy death even before he could gloat over the
sight. He richly deserved to be offered up as a
victim before his own mirror-idol.



44 PHYSICAL SCIENCE BK. i



XVII

1 Go now and laugh at the philosophers for discussing
the nature of the mirror and inquiring why our face
is reflected in it, and is turned toward us too. What
did nature mean by giving us real bodies and then
ordaining that phantoms of them also should be
visible ? What was her purpose in providing
material of the sort capable of receiving and return-

2 ing images ? Not, I trow, that we men might
use a looking-glass to pluck out the straggling
hairs of our beard and polish up our face.
Nature has never at any point merely provided
resources for luxury. First of all, her motive was
to show us the sun with his glare dulled, since
our eyes are too weak to gaze at him direct, and
without something to reflect him we should be

3 wholly ignorant of his shape. No doubt one may
study him as he rises and as he sets. But we should
know nothing of his true figure as he shines in
fierce noonday brightness, without his softening
ruddy glow, unless an image of him could be
mirrored in some liquid where he shines less
directly and is more easy to observe. In the second
place, we should be unable to see or investigate
the conjunction of two heavenly bodies, by which
the daylight is wont to be interrupted, unless we
could examine the reflections of sun and moon
in basins on the ground with comparative freedom.

4 In the third place, mirrors were discovered in order
that man might come to know himself.

Many benefits have ensued ; first, the knowledge
of self, after that, devices to secure specific results.
The comely man was taught to shun conduct that



xvn EVOLUTION OF THE MIRROR 45

would degrade him. The uncomely learned that
bodily defects must be compensated by virtue of
character. The young man was reminded by his
vigour that youth was the time for learning and for
performing daring deeds of chivalry. The grey-beard
was warned to have respect for his hoary hair and
turn his thoughts sometimes to death. It was for 5
this that even objects in nature have afforded us the
opportunity of seeing ourselves. 1 A clear fountain
or a smooth stone gives each back his image. In
the poet s words :

Lately I saw myself on the shore,
When the sea stood calm without a breath of wind.

What, think you, was the style of life of the people
who dressed at a mirror of this kind ? The age was
unsophisticated, satisfied with what supplies chance
presented. It did not as yet degrade a boon into a
vice, or turn nature s invention to purposes of lust
and luxury. At first, chance revealed to each his 6
form. In due time the inherent self-love of man
kind endeared the sight of their own figure, and
they came to look more frequently into the mirror
held up by nature in which they had first beheld
their image. Later on, when a worse race of men
ransacked the very bowels of the earth for treasure
better hid more deeply, iron first came into use ;
its production might have caused no damage had
the world produced only that one metal. But then 7
in good earnest were brought to light the other
precious banes of earth. Their smooth surface
presented the image of their possessors, who had
in view some quite different purpose. One saw his

1 The meaning may be, In addition, i.e. to artificial mirrors, objects in
nature, etc.



46 PHYSICAL SCIENCE BK. i

reflection in a cup, another in a brass vessel pro
cured for some ordinary use. Presently a round
mirror was constructed specially to render this
service : it was not as yet of polished silver, but of
a common brittle ware.

The men of ancient days lived a homely life ; they
thought themselves smart enough if they washed off
in the stream of the river the dirt contracted in their
work. But even then they bestowed pains on dress
ing their hair and combing out their flowing beards.

s In this part of the toilet each attended to himself and
at the same time helped his neighbour. The thick
streaming hair of the men, which it was of old the
fashion to wear, was, of course, combed out by the
wives. But sometimes they thought themselves
handsome enough without any such artistic hand,
and they just shook it out for themselves as spirited
animals do their mane. Afterwards, when luxury
had now gained sway, embossed mirrors of gold and
silver of full-length size were made, and at last they
were actually adorned with precious stones. One
of these has ere now cost a woman more than the
amount of a dowry given in the old days at the
public expense to the penniless daughters of famous

9 generals. Do you suppose Scipio s daughters bought
mirrors chased with gold from the iron money
that their dowry was paid in ? Happy the poverty
that gave occasion to earn such a title to glory !
The Senate would not have dowered them if they
had been able to afford mirrors. Whoever the
man was to whom the Senate acted the part of
father-in-law, he knew that he had got a wife that
was above suspicion. Nowadays the whole of the
dowry that the Roman people gave Scipio would
not be enough to buy a single looking-glass for



xvn AN INSTR UMENT OF L UXUR Y 47

some of the loose, silly daughters of our freedmen ! 10
Luxury has been gradually developed merely by
the possession of wealth, and has now gone to
oppressive lengths ; therewith vices have received
an immense accession of strength. In short, every
thing has got so mixed up through our perverted
refinements that all that used to be regarded as
the decoration of women has become part and
parcel of the outfit of man ; I am understating,
it is now an essential portion of a soldier s kit.
The mirror was introduced for the sake of the toilet ;
nowadays there is no vice to which it is not an
indispensable adjunct.