One of the finest accounts ever given of the nature of thunderbolts is that mentioned by Adrianus Tollius in his edition of 'Boethius on Gems.' He gives illustrations of some neolithic axes and hammers, and then proceeds to state that in the opinion of philosophers they are generated in the sky by a fulgureous exhalation (whatever that may look like) conglobed in a cloud by a circumfixed humour, and baked hard, as it were, by intense heat. The weapon, it seems, then becomes pointed by the damp mixed with it flying from the dry part, and leaving the other end denser; while the exhalations press it so hard that it breaks out through the cloud, and makes thunder and lightning. A very lucid explanation certainly, but rendered a little difficult of apprehension by the effort necessary for realising in a mental picture the conglobation of a fulgureous exhalation by a circumfixed humour.
One would like to see a drawing of the process, though the sketch would probably much resemble the picture of a muchness, so admirably described by the mock turtle. The excellent Tollius himself, however, while demurring on the whole to this hypothesis of the philosophers, bases his objection mainly on the ground that, if this were so, then it is odd the thunderbolts are not round, but wedge-shaped, and that they have holes in them, and those holes not equal throughout, but widest at the ends. As a matter of fact, Tollius has here hit the right nail on the head quite accidentally; for the holes are really there, of course, to receive the haft of the axe or hammer. But if they were truly thunderbolts, and if the bolts were shafted, then the holes would have been lengthwise, as in an arrowhead, not crosswise, as in an axe or hammer. Which is a complete reductio ad absurdum of the philosophic opinion.
Some of the cerauniæ, says Pliny, are like hatchets. He would have been nearer the mark if he had said 'are hatchets' outright. But this aperçu, which was to Pliny merely a stray suggestion, became to the northern peoples a firm article of belief, and caused them to represent to themselves their god Thor or Thunor as armed, not with a bolt, but with an axe or hammer. Etymologically Thor, Thunor, and thunder are the self-same word; but while the southern races looked upon Zeus or Indra as wielding his forked darts in his red right hand, the northern races looked upon the Thunder-god as hurling down an angry hammer from his seat in the clouds. There can be but little doubt that the very notion of Thor's hammer itself was derived from the shape of the supposed thunderbolt, which the Scandinavians and Teutons rightly saw at once to be an axe or mallet, not an arrow-head. The 'fiery axe' of Thunor is a common metaphor in Anglo-Saxon poetry. Thus, Thor's hammer is itself merely the picture which our northern ancestors formed to themselves, by compounding the idea of thunder and lightning with the idea of the polished stone hatchets they dug up among the fields and meadows.
Flint arrowheads of the stone age are less often taken for thunderbolts, no doubt because they are so much smaller that they look quite too insignificant for the weapons of an angry god. They are more frequently described as fairy-darts or fairy-bolts. Still, I have known even arrow-heads regarded as thunderbolts, and preserved superstitiously under that belief. In Finland, stone arrows are universally so viewed; and the rainbow is looked upon as the bow of Tiermes, the thunder-god, who shoots with it the guilty sorcerers.
But why should thunderbolts, whether stone axes or flint arrowheads, be preserved, not merely as curiosities, but from motives of superstition? The reason is a simple one. Everybody knows that in all magical ceremonies it is necessary to have something belonging to the person you wish to conjure against, in order to make your spells effectual. A bone, be it but a joint of the little finger, is sufficient to raise the ghost to which it once belonged; cuttings of hair or clippings of nails are enough to put their owner magically in your power; and that is the reason why, if you are a prudent person, you will always burn all such off-castings of your body, lest haply an enemy should get hold of them, and cast the evil eye upon you with their potent aid. In the same way, if you can lay hands upon anything that once belonged to an elf, such as a fairy-bolt or flint arrowhead, you can get its former possessor to do anything you wish by simply rubbing it and calling upon him to appear. This is the secret of half the charms and amulets in existence, most of which are either real old arrowheads, or carnelians cut in the same shape, which has now mostly degenerated from the barb to the conventional heart, and been mistakenly associated with the idea of love. This is the secret, too, of all the rings, lamps, gems, and boxes, possession of which gives a man power over fairies, spirits, gnomes, and genii. All magic proceeds upon the prime belief that you must possess something belonging to the person you wish to control, constrain, or injure. And, failing anything else, you must at least have a wax image of him, which you call by his name, and use as his substitute in your incantations.
On this primitive principle, possession of a thunderbolt gives you some sort of hold, as it were, over the thunder-god himself in person. If you keep a thunderbolt in your house it will never be struck by lightning. In Shetland, stone axes are religiously preserved in every cottage as a cheap and simple substitute for lightning-rods. In Cornwall, the stone hatchets and arrowheads not only guard the house from thunder, but also act as magical barometers, changing colour with the changes of the weather, as if in sympathy with the temper of the thunder-god. In Germany, the house where a thunderbolt is kept is safe from the storm; and the bolt itself begins to sweat on the approach of lightning-clouds. Nay, so potent is the protection afforded by a thunderbolt that where the lightning has once struck it never strikes again; the bolt already buried in the soil seems to preserve the surrounding place from the anger of the deity. Old and pagan in their nature as are these beliefs, they yet survive so thoroughly into Christian times that I have seen a stone hatchet built into the steeple of a church to protect it from lightning. Indeed, steeples have always of course attracted the electric discharge to a singular degree by their height and tapering form, especially before the introduction of lighting-rods; and it was a sore trial of faith to mediæval reasoners to understand why heaven should hurl its angry darts so often against the towers of its very own churches. In the Abruzzi the flint axe has actually been Christianised into St. Paul's arrows—saetti de San Paolo. Families hand down the miraculous stones from father to son as a precious legacy; and mothers hang them on their children's necks side by side with medals of saints and madonnas, which themselves are hardly so highly prized as the stones that fall from heaven.
Another and very different form of thunderbolt is the belemnite, a common English fossil often preserved in houses in the west country with the same superstitious reverence as the neolithic hatchets. The very form of the belemnite at once suggests the notion of a dart or lance-head, which has gained for it its scientific name. At the present day, when all our girls go to Girton and enter for the classical tripos, I need hardly translate the word belemnite 'for the benefit of the ladies,' as people used to do in the dark and unemancipated eighteenth century; but as our boys have left off learning Greek just as their sisters are beginning to act the 'Antigone' at private theatricals, I may perhaps be pardoned if I explain, 'for the benefit of the gentlemen,' that the word is practically equivalent to javelin-fossil. The belemnites are the internal shells of a sort of cuttle-fish which swam about in enormous numbers in the seas whose sediment forms our modern lias, oolite, and gault. A great many different species are known and have acquired charming names in very doubtful Attic at the hands of profoundly learned geological investigators, but almost all are equally good representatives of the mythical thunderbolt. The finest specimens are long, thick, cylindrical, and gradually tapering, with a hole at one end as if on purpose to receive the shaft. Sometimes they have petrified into iron pyrites or copper compounds, shining like gold, and then they make very noble thunderbolts indeed, heavy as lead, and capable of doing profound mischief if properly directed. At other times they have crystallised in transparent spar, and then they form very beautiful objects, as smooth and polished as the best lapidary could possibly make them. Belemnites are generally found in immense numbers together, especially in the marlstone quarries of the Midlands, and in the lias cliffs of Dorsetshire. Yet the quarrymen who find them never seem to have their faith shaken in the least by the enormous quantities of thunderbolts that would appear to have struck a single spot with such extraordinary frequency This little fact also tells rather hardly against the theory that the lightning never falls twice upon the same place.
Only the largest and heaviest belemnites are known as thunder stones; the smaller ones are more commonly described as agate pencils. In Shakespeare's country their connection with thunder is well known, so that in all probability a belemnite is the original of the beautiful lines in 'Cymbeline':—
Fear no more the lightning flash,
Nor the all-dreaded thunder stone,
where the distinction between the lightning and the thunderbolt is particularly well indicated. In every part of Europe belemnites and stone hatchets are alike regarded as thunderbolts; so that we have the curious result that people confuse under a single name a natural fossil of immense antiquity and a human product of comparatively recent but still prehistoric date. Indeed, I have had two thunderbolts shown me at once, one of which was a large belemnite, and the other a modern Indian tomahawk. Curiously enough, English sailors still call the nearest surviving relatives of the belemnites, the squids or calamaries of the Atlantic, by the appropriate name of sea-arrows.