LECTURER ON EDUCATION IN THE UNIVERSITY OF ABERDEEN WITH NOTES ON THE TREATISE BY SIR ARCHIBALD GEIKIE PRESIDENT OF THE ROYAL SOCIETY MACMILLAN AND CO., LIMITED ST. MARTIN’S STREET, LONDON 1910 _Plurimum ad inveniendum contulit qui speravit posse reperiri._ PREFACE This book is intended primarily for English readers, to most of whom it will probably be at least new. Thomas Lodge, the well-known dramatist, published in 1614 a translation of the whole of Seneca’s prose works (except the _Apocolocyntosis_), but no English editor or commentator seems to have turned his attention to the _Quaestiones Naturales_, either before or since. Lodge’s translation, a folio volume of nearly a thousand pages, was probably very good for its day, but is now out of date.
The Introduction is designed to give a setting to the translation, and to answer a few of the questions that would naturally occur to the mind of an intelligent reader who was not a classical scholar. In the Index also some details are included that may be helpful to those who have neither time nor opportunity for hunting up historical and other allusions in books of reference. The object has been to make the volume self-interpreting, though it may be that the course has not always been judiciously steered between too little and too much.
The _Quaestiones Naturales_ must be regarded as occupying historically an important position. It was the latest deliverance of the classical world upon the subject of physical speculation. Its currency during the Middle Ages rendered it for many centuries the chief authority in science in Western Europe. Its cosmology represented not only popular but also educated opinion, and became the source of many of the accepted ideas concerning the universe that passed into early modern literature in our own and other countries.
Indebtedness to editors of Seneca and to others, which has been very great, is acknowledged as fully as possible in the Introduction and elsewhere where help has been availed of. The interest taken in the book by various friends is also gratefully acknowledged. Professor Sir Joseph Larmor and Professor J. Arthur Thomson have made several useful suggestions. Professor Herbert J. C. Grierson has very kindly read the proofs and given valuable assistance in other respects. But my chief acknowledgments are due to Sir Archibald Geikie. To him the translation owed its inception: his constant aid and encouragement have enabled me to complete a task from which I should probably have otherwise shrunk. I am indebted to him also for the Commentary appended to the translation, in which the questions treated by Seneca are considered from the point of view of modern Science. It has been to him a labour of love: may our readers enjoy something of the same satisfaction!
J. C.
Old Aberdeen, CONTENTS PREFACE v INTRODUCTION xxi BOOK I [METEORS, HALO, RAINBOW, MOCK SUN, ETC.]
PREFACE PAGE Contrast between human (moral) philosophy and divine (natural, physical). The sublime character of the latter which lifts us above the contemplation of the littlenesses of the earth and earthly life to the knowledge of God and His nature.
Compared with astronomical conceptions and dimensions the world of man is but as a threshing-floor, the haunt of ants.
The mind of man attains its true height in contemplation and investigation of these sublime facts. Some of the problems thus raised 3 CHAP.
I. Meteoric fires--_she-goat_, _kid_, etc. Occasions of their appearance; connection of portent with event. Explanation of the phenomena. They may be due to pressure of the atmosphere. Aristotle attributes them to the effect of terrestrial evaporation: difference of density causes various outbursts of this kind. They are analogous to lightning, but less violent 8 II. _Halos._ Produced by the light of a heavenly body striking the surrounding air and forming a circle as a stone does when thrown into a pond. Formed far away from the heavenly body and comparatively near the earth in the region of the wind. Require a particular state of the atmosphere neither too dense nor too thin. More frequent at night than day for this reason: by day the sun rarefies the air too much by its heat. Method of dissipation gives indication of wind or rain. Calmness a condition of formation, as in the analogous case of water 12 III. _Rainbows._ Generally by day, produced by inequalities of surface and density in clouds. Another species seen in a burst pipe or a fuller at work. Various explanations.
Light and shade will not explain the varied colours. Some explain the rainbow as a confused reflection of the sun from individual drops of rain: every bounded surface, large or small, thus reflects--fish-pond and dew-drop equally.
Aristotle attributes the confusion of colours to weakness of human sight; parallels may be found in persons whose sight is abnormally weak. As the innumerable drops, apparently without intervals, fall, human vision fails to distinguish severally the reflections of the sun, which thus become blended and confused. Vision is similarly deceived in the case of an oar in water, apples in a glass globe, etc., even in the size and movements of the sun himself. At any rate the rainbow requires both sun and cloud, and these opposite to each other. These two in operation produce the varieties of colour 16 IV. That the rainbow is an image is shown by the relation of sun to cloud in position, by the rapidity of formation and dispersion. Artemidorus’ explanation of the shape of the cloud (concave), and the consequent position of the red in the rainbow 22 V. Arguments to show that the cloud is coloured by the sun, like a dove’s neck or a peacock’s tail, and that the rainbow is not a _reflection_ of the sun. The position (opposite) would be equally necessary in this case. Answer to this contention by Posidonius. The colour effects. Author agrees with Posidonius’ position but not his arguments. The only _proof_ is the geometrical one 23 VI. Arguments from the size--never more than a semicircle--and shape of the bow. As the colour, whether real or reflected, is derived from the sun, so must also the shape be. The size is accounted for by the magnifying power of water, glass, etc. The sun as he appears in the rainbow is seen through moisture 28 VII. The arguments from the dispersion of the sun’s rays through glass (prism). Contention that they confirm author’s view 30 VIII. The form once more; why it is never larger than a semicircle. A wrong explanation refuted. Explanation of Aristotle’s remark as to the seasons of rainbows, in summer only in the morning or evening, in autumn at any time 31 IX. _Streaks_ or _weather-galls_. Merely abortive or imperfect rainbows 33 X. Relations and differences of _halos_, _bows_, and _weather-galls_ 34 XI. _Mock suns._ Their appearance and position in relation to the sun. They are a reflection of the sun in a suitable medium 34 XII. The formation of a mock sun may be compared to the image of the sun in eclipse as seen reflected in a dish of oil or pitch: the medium must be adapted to give the impression.
The mock sun requires a certain consistency of cloud, failing which, a different effect is produced--obscuration, dissipation, etc. 35 XIII. There may be two mock suns simultaneously. Some think the one is a reflection of the other, the clouds acting as mirrors set opposite to one another. Mock suns, especially in the South, are a sign of rain 36 XIV. Other celestial fires. “_Cave meteors_,” “_Barrel meteors_,” “_Chasms_,” with a brief description of each. The rapidity of their flight, just as of lightning, deceives the sight. Their origin and cause. They indicate wind 37 XV. _Gleams_ (_flashes_, σέλα). Their production and motions, varieties of them. Some do damage. Some are analogous to comets. “_Bearded_,” “_torches_,” “_cypress_” are different kinds. “_Beams_” and “_barrels_” may be of the same class.
A curious case where such an appearance raised an alarm of fire. They are real fires. On the contrary, rainbows and halos are mere reflections. Mirrors have this wonderful power of false presentation 39 XVI. The “mirrored den” of Hostius Quadra 41 XVII. The philosophy of the looking-glass. The evolution of mirrors. Mirrors of full length are now used. They cost a fortune greater than the Senate gave Scipio’s daughters.
A harmless necessary device has become an instrument of luxury, the adornment of women, the burden of men, nay, part of the kit of the soldier 44 BOOK II [THE NATURE OF AIR. THUNDER AND LIGHTNING] [I.-XI. Prefatory to treatment of thunder and lightning, descriptive of the nature of the air, in which these phenomena occur.]
I. Divisions of physical science--astronomy, meteorology, geography. Cross divisions, _e.g._ earthquakes, belong to meteorology, being produced by air; so the earth, as a planet, belongs to Astronomy but its properties belong to Geography 51 II. Unity and composition in bodies. The analogy of the seen applies to the unseen. The atmosphere is possessed of unity (_unitas_) 52 III. Parts and material of bodies distinguished. In the human body blood is both 54 IV. The atmosphere is an integral part of the universe: has unity 54 V. The earth is both part and material of the universe. From it nourishment is supplied to the latter 55 VI. The atmosphere has unity--is not compact of atoms, otherwise it could not exert tension, which is one of its main features, with endless manifestations 55 VII. There is no vacuum in the air, as the analogy of water shows 57 VIII. The exertion of tension presupposes tensibility, just as motion does mobility. Its existence in air proved by the effects of air, which tosses about mountains, houses, walls, etc. The propagation of sight and sound proves the same 58 IX. Its tension is seen in raising water, as in the jet in the amphitheatre. Proofs from a ship upborne of water, a quoit flung from a height, sound heard through a wall 59 X. Varieties of density and temperature in the atmosphere: the central layer is coldest 60 XI. The lower parts are most subject to change. The cause of this is in part the earth, in part the sun, moon, and other stars. So much by way of preface to explain the nature of that atmosphere in which thunder and lightning occur 61 XII. _Lightning_, _thunder-bolt_, _thunder_. All agree that they occur in the clouds, but different explanations are given of their cause and relations. Anaxagoras connects them with the ether; Aristotle says they are due to exhalations of various kinds, from the earth, coming in contact with the clouds 62 XIII. The fire cannot be inherent in the clouds and fall from them. When it so comes it is forced 64 XIV. There is nothing inconsistent with this in the explanation given (I. xv.) of meteors. There may be an analogy with what is observed in cases of fire when isolated groups of houses take fire through gradual accumulation of heat 65 XV. Some (Stoics) think that spontaneous combustion takes place in the air 66 XVI. Difference between a flash of lightning and a bolt 66 XVII. Some explain the noise of thunder as due to hot meeting cold, as in the case of hot iron plunged into water 67 XVIII. Anaximander attributes the effects to air and explains all the phenomena by reference to it 67 XIX. Anaxagoras says it is the ether that acts on the lower atmosphere to produce them: it sends out fire 68 XX. Diogenes of Apollonia thinks that fire and air interact, producing one another, as may be observed in the various phenomena 68 XXI. Authorities discarded: independent explanation. A flash and a bolt are fire in some form: they differ only in degree 69 XXII. Analogy of fire on earth: it must apply above. Lightning due either to impact or friction. Hurricanes are a sufficient cause of the former 70 XXIII. Clouds and air may through friction also be a cause. The fires so produced are insubstantial and evanescent 71 XXIV. Fire by reason of its lightness levitates, just as water gravitates. But in the case of a bolt it is forced down, contrary to its nature, like a “weeping” tree 71 XXV. But it is said that wet clouds produce fire. How? 72 XXVI. There is no inconsistency in the combination in the same cloud of potential fire and water. A log burns at one end, exudes moisture at the other. An island on each of two occasions was thrown up by fire in the Aegean Sea, fire overcoming water. And clouds are, as a matter of fact, required for lightning: exceptions to this are only apparent 72 XXVII. Different kinds of thunder. The growling and the crashing, with their causes 75 XXVIII. In order to the sound of thunder, clouds of a particular shape must meet in a particular way. A bladder does not burst with a report if cut. A broad simultaneous blow over the whole cloud is necessary to an explosion 76 XXIX. The proper shape and the rupture of the cloud are necessary. Compare drums, etc. 77 XXX. According to some, clouds are not necessary to thunder: witness eruptions of Etna and the overthrow of Cambyses’ army, where particles of sand were the medium of the thunder and lightning. But in this case, too, a cloud was formed, it may be, a denser, and more solid than one composed of mere air, before the sound was emitted 77 XXXI. Strange effects of lightning 78 XXXII. Portents and events, their undoubted and widespread connection 79 XXXIII. Thunderbolts. Threefold division of the art of dealing with them 81 XXXIV. Mistaken views as to the relation of lightning to other presages. The former are of equal, not superior, value 82 XXXV. Fate cannot be changed by expiation and entreaty 83 XXXVI. “God is not a man” that he should change fate. What is the use, then, of rites? 84 XXXVII. Answer--Fate fixes some things only conditionally: the alternative issues are determined by the conduct, active or passive, of the worshipper 84 XXXVIII. This action of his is likewise a part of fate. The soothsayer, like the physician, is the minister of fate.
Discussion of free will deferred 85 XXXIX. Three classes or kinds of thunderbolts, as judged by their indications, according to Caecina 86 XL. These are kinds of prognostications rather than of bolts.
The different species of the latter are distinguished by their effects--boring, splitting, burning. Fine distinctions of Latin terms 87 XLI. A kind that stains or discolours. The Etruscan view of the three kinds of bolt according to _their_ division 88 XLII. The Etruscans knew what they were about in attributing certain motives and actions to Jupiter. Their theory was for the benefit of the ignorant mass of humanity 89 XLIII. “Which things are an allegory.” An example is set to earthly rulers to be merciful and consider well their judgments 90 XLIV. Jove does not change his missiles; but there are gradations in the offence to be punished. That is the lesson 91 XLV. By Jove the Etruscans meant, as we do, all that is greatest and best--Fate, Providence, Nature, the Universe 91 XLVI. He is the source of the thunder’s power, though he does not superintend each stroke. Why he spares the guilty is another affair, which will be discussed in another place 92 XLVII. An erroneous classification of thunderbolts according to time 92 XLVIII. It must be wrong, because the time is always limited. A better basis of treatment is that of Attalus. Place, time, person, etc., must all be looked into 93 XLIX. Caecina’s division, his names and their meanings 94 L. That of Attalus is much better, being based on the true signification 95 LI. The signification of some does not affect, of some does not reach, us 95 LII. The force of lightning as seen in different materials, and at different times in the same material (cf. xxxi.) 96 LIII. Poisonous effects: may be followed up afterwards.
Panegyric on philosophy 97 LIV. Returns to Posidonius’ (Aristotle’s) opinion as to the cause of thunder, an explosion of air 98 LV. The collision of clouds may produce it. Air is the cause in this instance also. Shooting stars are associated with thunder, but this is the exception, not the rule 98 LVI. Heraclitus and Caecina think sheet lightning an intermittent incipient fire. Change in the pronunciation of the Latin word 100 LVII. Lightning is probably due to the air turning into fire through rarefaction of the clouds. It is naturally most frequent in summer. Sheet and forked lightning differ in degree, not in kind 100 LVIII. Reasons for rapidity of lightning and its obliquity 101 LIX. Every story should have a moral. Death cannot be prevented; why fear it? It is cowardly and silly. Death by lightning is rather an honour than otherwise. Besides, fear is futile 102 BOOK III ON FORMS OF WATER PREFACE Having begun a mighty task in my old age I must make up for lost time by hurrying on. The magnitude of it is actually an incentive to effort. Such studies are far superior to the historian’s task of recording the deeds of the robbers and butchers of mankind. The former raise us above the vicissitudes of fortune. “The principal thing” is to have a pure heart and clean hands, to escape slavery to self. The study of the universe exalts us to this 109 I. The cause of rivers and their varieties. Waters vary in amount at different seasons, in temperature, in medicinal qualities 114 II. Varieties of taste, weight, colour, utility to health, consistency 115 III. Gravitation or the force of air determines the flow of water. Surface and spring water: they may be combined as in Lake Fucinus 115 IV. Why is the sea not filled nor the earth drained dry by rivers? 116 V. Some hold that what flows into the sea returns by secret passages cleansed of its salinity 116 VI. Some think rain supplies the rivers, and in proof cite the interior of Africa as contrasted with Gaul and Germany 117 VII. Objections to this argument. Rain does not penetrate more than 10 feet. If the earth is dry, it absorbs the rain; if it is saturated, the rain runs off. Again, rivers rise in rocks and mountains, where what rain ever fell must have run off. Rich wells of “living” water are found in the driest ground at depth. Fountains well out at mountain tops 117 VIII. The interior of the earth is, according to some, a huge receptacle of fresh water 118 IX. Others think the air which is contained within the earth being prevented from circulating turns into water 119 X. But indeed the four elements are all interchangeable 120 XI. Though the supply of water is perennial, rivers and springs are intermittent 121 XII. The abundance of water is no difficulty, since it is a fourth part of the universe 123 XIII. The relation of water to the other elements. Thales’ silly notion that the earth sails in water like a ship at sea 124 XIV. The Egyptians divide each of the elements into male and female 125 XV. The veins of the earth resemble those of the human body.
There are likewise the analogies of marrow, mucus, etc., of injuries and of bleeding, of parturition, perspiration, etc. 125 XVI. Intermittent fountains are an illustration of seasonal activity. The great vacant spaces of the earth and their tenants. Underground fish 128 XVII. The incredible wonders of nature are paralleled and even outdone by the excesses of luxury 129 XVIII. The extravagances of luxury, which make a wise man mad 130 XIX. To return--a sudden eruption of water casts up fish, generally poisonous. This points to the unfailing supply of subterranean water 132 XX. Various tastes of water due to four causes; qualities of water--petrifying, soporific, intoxicating, fatal 133 XXI. The same pestilential influence as taints rivers is perceived in caves: the noxious rivers flow from or through them 134 XXII. The Ocean and seas are coeval with the universe. So probably are abnormal rivers like the Danube and the Nile 135 XXIII. Rain and surface water must be added to subterranean 135 XXIV. The causes of hot springs 136 XXV. Poisonous rivers. Colouring power of others. Great specific gravity of certain waters, its effects and cause 137 XXVI. Intermittent rivers and springs. Means possessed by river, fount, and sea of purifying themselves 141 XXVII. Digression on the universal deluge which will destroy the world. Nature is niggardly in creation, lavish in destruction. Ovid is unequal in his treatment of this catastrophe 143 XXVIII. Further imaginative pictures of what water can do by way of destruction. Alternative methods of destroying the earth--water and fire 148 XXIX. Further possibilities of the same character. Distinctions of seas, gulfs, etc., will all be obliterated; nature and the works of man will alike be overthrown 150 XXX. Nature shows by the chafing of the sea that she designs to inundate the world. A deluge is part of the fore-ordained plan. But there will be a new earth and a new race of men who will not sin--for a time 154 BOOK IV CONTAINING A DISCUSSION OF SNOW, HAIL, AND RAIN. [THE NILE] PREFACE The dangers of flattery and its insidiousness. If you must have praise, praise yourself. Lucilius has good cause: he must not, however, think too much of himself because he is governor of that historic province Sicily, which has ere now decided the fate of generals and of empire 159 I. Leaving Sicily and its marvels let us deal with the omitted part of the last book, the Nile. There is no real analogy between it and the Danube 166 II. The course of the Nile; its cataracts. The inundation of the river. Its meaning to Egypt. Its denizens; crocodiles and dolphins in conflict. Causes of the overflow: melting of snow; Etesian Winds; drying up of the springs through internal heat of the earth in winter; the attraction of the sun in Africa draws water from the sea to fill up the gap caused by evaporation [none of the accounts apparently accepted] 167 III. Origin of hail; why it differs from snow 177 IV. Causes of snow in winter, hail in spring 179 V. It is said that the cooler air of the North (Scythia, etc.)
is stirred by the melting of the snow in spring and floats South, causing hail instead of rain 180 VI. Hail, it is again alleged, is averted by sacrifice. If there is not a victim handy you have merely to prick your finger! 181 VII. This belief in the power of blood was an ancient superstition 182 VIII. Three causes why the air near the earth is warmest, and therefore produces snow rather than hail 182 IX. Democritus’ view--dense bodies are heated most quickly, and retain their heat longest 183 X. The air nearest the earth is denser than elsewhere 184 XI. The tops of mountains, it is urged, should be warmer because nearer the sun. The difference is wholly inappreciable if we adopt the scale of the universe, the true one 184 XII. The comparatively mild air near the earth causes snow, but not hail 186 XIII. The despicable luxury of the effeminate Romans, who bought snow, bathed in it, and must resort even to ice to cool the unnatural feverish thirst born of their indulgence 186 BOOK V TREATING OF WINDS AND MOVEMENT OF THE ATMOSPHERE I. Definition of _wind_--air flowing in one direction. The air, like the sea, is always moving, even when it is thought to be still; hence the necessity of the additional qualification--in one direction 193 II. Democritus says wind arises from a multitude of atoms in a small space striving to get free, just like a crowd jostling each other 194 III. But wind does not thus depend on density; cloudy or misty weather does not necessarily produce wind, while wind is produced when the morning sun dissipates the air. Democritus is, therefore, wrong 195 IV. Wind arises in two ways--from the interior of the earth by emission--like wind on the stomach!--and from evaporation 196 V. The air has inherent power of movement, which is the chief cause of wind, evaporation being a less powerful one. Water has the power of moving and of imparting life to animals and plants 197 VI. Fire even, the destroyer, sometimes generates life. Air in like manner has a peculiar power of its own 197 VII. _Breezes before dawn_ arise from rivers, etc. Do not last long 198 VIII. _The “gulf” wind_ (ἐγκολπίας): its origin and duration 198 IX. Connection of winds with seasons of the year and with the heat and light of the sun. The sun does not directly cause the winds 200 X. Some cite the Etesian Winds as proof that he does. They blow in summer when the snows melt and the moisture is carried South 201 XI. But as to the effect of the sun, there is no analogy between the Etesian Winds, which do not spring up till late in the day, and the winds which rise at dawn and fall as the day advances 202 XII. _Cloud squalls_ (ἐκνεφίας). Their formation and combinations 203 XIII. The breaking up of clouds produces wind. Air, in an effort to get free, or heat, may produce this. Interruption of free passage may produce a whirlwind, just as an obstacle in a river a whirlpool. _Violent whirlwinds_ take fire (πρηστήρ).
Some winds produce different ones. An analogy holds between air and drops of moisture. A union of forces in air or in dew is necessary to give impulse and produce a current. Air and wind are merely a matter of degree 204 XIV. Mode in which the subterranean winds are generated and make their escape 205 XV. Ancient miners of Philip’s saw rivers and vast underground reservoirs. It is some consolation to read such a story, which shows greed is no new vice: the older generations were as reckless as we are in their quest for treasure better hid 207 XVI. The four _cardinal winds_. The full list includes twelve.
Their names and directions 208 XVII. The great circles of the earth which give twelve divisions, and therefore prescribe the possible number of the winds 210 XVIII. The uses of wind and the illustration afforded of the wisdom of Providence. The crops are dependent on it. So is commerce. But we make the sea a highway to war and not to peace. We go to seek for death, as if it were not always near. Xerxes, Alexander, Crassus are warnings of the mischievous use of power to cross the sea. Better, perhaps, the winds had never been given at all. But the value of a natural gift must not be estimated by the depraved use of it. Every gift, even sight and speech, man has perverted in the same way 212 BOOK VI TREATING OF EARTHQUAKES CHAP. PAGE I. Earthquake at Pompeii and the alarm it caused, many giving up Campania as a residence altogether. If the solid earth fail, what can be done? Refuge from tempest and fire and thunderstorm and war is possible, but not from earthquake.
But (1) the whole earth is subject to such movement: we cannot escape by changing our ground--Tyre, Asia Minor, Achaia have all suffered. (2) Death is the same in whatever form it come, the circumstances matter not, a stone is all one with a mountain 221 II. We cannot escape death. The hopeless find refuge in despair.
The knowledge of our frailty and mortality is our true solace. Death must come, a death with circumstance is rather to be preferred than otherwise. In an earthquake the earth shows itself mortal as men are 225 III. Our fears are due to ignorance. Through lack of a philosophic view of the universe we consider phenomena strange which are merely rare, _e.g._ eclipses. Fear may be removed by knowledge 228 IV. The study of such problems is the very worthiest; it reveals