CHAPTER IV

FIREBALLS

Here we penetrate into what is, perhaps, the most mysterious, and

certainly the least understood domain of thunder and lightning.

Among all the electrical phenomena to be observed in the atmosphere,

there is nothing stranger than those fireballs of which we have

already spoken, and which in form and size recall the electric lights

in our Paris boulevards. Curious the contrast between electricity

tamed and civilized and electricity running wild! Between the arc

lights fulfilling their peaceful and useful function as substitutes

for the sun, and these dread engines of destruction sowing death and

havoc!

It is not long since the existence of these fireballs has been

acknowledged by scientists as an actual fact. Until quite recent times

they were regarded as the figment of excited imaginations, and wise

men smiled at the wild stories of their ravages. Their reality has now

been established, however, beyond the possibility of doubt.

In shape they are not always quite spherical, though this is their

normal appearance; and although their contours are usually clearly

defined, they are sometimes encircled by a kind of luminous vapour,

such as we often see encircling the moon. Sometimes they are furnished

with a red flame like a fuse that has been lit. Sometimes their course

is simply that of a falling star. Sometimes they leave behind them a

luminous trail which remains visible long after they themselves have

disappeared. They have been described as looking like a crouching

kitten, an iron bar, a large orange--so harmless apparently, that you

were tempted to put out your hand to catch it. There is record of one

being seen as large as a millstone.

One remarkable thing about them is the slowness with which they move,

and which sometimes enables their course to be watched for several

minutes. In our first chapter we gave several instances of the

occurrence of fireballs. Let us look at some more. Here is one taken

from Arago's learned treatise upon thunder. The record is from the pen

of Batti, a marine painter in the service of the Empress of Austria

and resident at Milan.

"In the month of June, 1841, I was staying at the Hôtel de l'Agnello

in a room on the second floor, overlooking the Corso dei Servi. It was

about six in the afternoon. The rain was coming down in torrents, and

the darkest rooms were lit up by the lightning flashes better than our

rooms generally are by gas. Thunder broke out every now and again with

appalling violence. The windows of the houses were closed, and the

streets were deserted, for, as I have said, there was a steady

downpour, and the main road was turned into a torrent. I was sitting

quietly smoking, and looking out at the rain, which an occasional ray

of sunlight set flashing like threads of gold, when I suddenly heard

voices in the street calling out 'Guarda, guarda!'--'Look, look!' and

at the same moment a clatter of hob-nailed boots. After half an hour

of absolute silence, this noise attracted my attention. I ran to the

window, and looking to the right, in the direction of the clamour, I

saw a fireball making its way down the middle of the road on a level

with my window, in a noticeably oblique direction, not horizontally.

Eight or ten persons, continuing to call out 'Guarda, guarda!' kept

pace with it, walking down the street, stepping out quickly. The

meteor passed my window, and I had to turn to the left to see what

would be the end of its caprice. After a moment, fearing to lose sight

of it behind some houses which jutted out beyond my hotel, I went

quickly downstairs and into the street, and was in time to see it

again and to join those who were following its course. It was still

going slowly, but it was now higher up, and was still ascending--so

much so that after a few minutes it hit the cross upon the clock tower

of the Chiesa dei Servi and disappeared. Its disappearance was

accompanied by a dull report like that of a big cannon twenty miles

away when the wind carries the sound.

"To give an idea of the size and colour of this globe of fire, I can

only compare it to the appearance of the moon as one may see it

sometimes rising above the Alps on a clear night in winter, and as I

myself have seen it at Innsbrück--that is to say, of a reddish yellow,

with patches on it almost of red. The difference was that you could

not see the contours of the meteor distinctly as you could the moon,

and that it seemed to be enveloped in a luminous atmosphere of

indefinite extent."

This fireball was an innocuous one. We may take next, by way of

contrast, the case of one which wreaked terrible damage and loss of

life.

On July 27, 1789, at about three o'clock in the afternoon, a fireball

of about the size of a cannon-ball, fell in a great hall at Feltri

(Marche Trevisane) in which six hundred people were seated, wounded

seventy and killed ten, putting out all the lights.

On July 11, 1809, about eleven o'clock in the morning, a fireball

penetrated into the church of Chateauneuf-les-Moustiers (Basses-Alpes)

just as the bell was ringing and a large congregation had taken their

seats. Nine persons were killed on the spot and eighty-two others were

wounded. All the dogs that had got into the church were killed. A

woman who was in a hut on a neighbouring hill saw three fireballs

descend that day, and made sure they would reduce the village to

ashes.

Müsschenbroek recounts the following incident which took place at

Solingen in 1711. M. Pyl, the Pastor at Duytsbourg, was preaching one

Sunday, when in the middle of a storm a fireball fell into the church

through the clock tower and exploded. The sanctuary was set on fire

and became thick with smoke. Three persons were killed and more than a

hundred were wounded.

From the _Bulletin_ of the Société Astronomique de France the

following narrative contributed to it by Mlle. de Soubbotine, a member

of this society, has been taken:--

"A terrible storm broke out at Ouralsk on May 22, 1901. It was a

_fête_ day and the streets were thronged with people. Towards five in

the afternoon some young men and girls, twenty-one in all, had taken

refuge in the vestibule of a house, and a girl of seventeen, Mlle. K.,

had sat down on the threshold, her back turned towards the street.

Suddenly there was a violent clap of thunder, and in front of the door

there appeared a dazzlingly brilliant ball of fire, gradually

descending towards where they were all grouped. After touching Mlle.

K.'s head, who bowed down at once, the fireball fell on the ground in

the middle of the party, made a circuit of it, then forcing its way

into the room of the master of the house, whose boots it touched and

singed, it wreaked havoc with the apartment, broke through the wall

into a stove in the adjoining room, smashed the stove-pipe, and

carried it off with such violence that it was dashed against the

opposite wall, and went out through the broken window.

"After the first feeling of fright, this is what transpired. The door

near which Mlle. K. was seated had been thrown back into the court,

and in the ceiling there were two holes of about 18 centimetres each.

"The young girl, still seated with her head bowed down, looked as

though she were asleep. Some of the people were walking in the

courtyard, having seen and heard nothing, and the others were all

lying in the vestibule in a dead faint. Mlle. K. was dead. The

fireball had struck her on the nape of her neck and had proceeded down

her back and left hip, leaving a black mark all along. There was a

sore on one hand, with some blood on it, and one of her shoes was torn

completely off, and there was a small hole in one of the stockings.

"All the victims became deaf."

On September 10, 1845, at about two in the afternoon, in the course of

a violent storm, a fireball came down the chimney into a room in a

house in the village of Salagnac (Creuse). A child and three women who

were in the room suffered no harm from it. Then it rolled into the

middle of the kitchen, and passed near the feet of a young peasant who

was standing in it. After which it went into an adjoining room, and

disappeared without leaving any trace. The women tried to persuade the

man to go in and see whether he could not stamp it out, but he had

once allowed himself to be electrified in Paris, and thought it

prudent to refrain. In a little stable hard by, it was found

afterwards that the fireball had killed a pig. It had gone through the

straw without setting fire to it.

On July 12, 1872, a new form of fireball made its appearance in the

Commune of Hécourt (Oise). It was of the size of an egg, and it was

seen burning upon a bed. Efforts were made in vain to extinguish it,

and presently the entire house, together with the neighbouring

dwellings and barns, became a prey to the flames.

On October 9, 1885, at 8.25 p.m., during a violent storm, a globe of

fire of the size of a small apple was seen coming into a ground-floor

room in a house at Constantinople through an open window, the family

being at table in this room at the time. It first played round a

gas-jet, then, moving towards the table, it passed between two guests,

went round a lamp hanging over the centre of the table, and then

precipitated itself into the street, where it exploded with an

appalling crash, but without having caused any damage or hurt anybody.

Not far from the scene of this phenomenon there are a number of

buildings provided with lightning conductors. The fireball left no

trace of smell behind it.

Here is another curious narrative of a fireball.

A party of five women took refuge during a storm in the entrance to a

house in order to escape from the rain and the lightning.

They had scarcely gained the doorway when there was a tremendous

thunderclap which sent them flying backward--and two girls who had

joined them--knocked senseless by lightning in the form of a fireball.

One of the girls remained unconscious for a long time; all the others

were more or less seriously injured, but all recovered. The strangest

circumstance in connection with this affair, however, still remains to

be told.

[Illustration: SINGULAR CASE OF THREE FIREBALLS OBSERVED IN PARIS ON

JUNE 10, 1905, BY M. H. RUDAUX.

They were seen to descend in this way upon the lightning conductor

above the Palais Royal electric-power station. This engraving, after a

sketch made at the time by M. Rudaux, appeared in _La Science

Illustrée_, for August, 1905.]

On the same side of the street as the passage, in a neighbouring

house, nine or ten yards away, in a ground-floor room of which the

door was shut, a young woman was working at a sewing-machine. At

the moment of the thunderclap, she experienced a violent shock

throughout her whole body, and a fierce burning sensation in the

hollow of her back. It was found afterwards that between the

shoulder-blades and also on her leg, she had been badly scorched, but

the wounds quickly healed. Now, in the room of this victim, no trace

was to be found of the passing of the fireball, neither on the

ceiling, nor on the floor, nor on the walls. There was absolutely

nothing to show how the electric fluid could have made its way in from

the spot in which the fireball had exploded in the neighbouring house,

separated from it by two thick walls.

Mysterious, is it not? The fireball seems to dwindle out of sight. In

some cases, it seems to reduce itself into vapour in order to pass

from one place to another.

With animals these fireballs seem deadlier and more merciless than

with human beings.

Thus, on February 16, 1866, a thunderstorm descended upon a farm in

the Commune of Chapelle-Largeau (Deux-Sèvres), and the circumstances

attending its explosion are too remarkable to be overlooked. After a

tremendous thunderclap, a young man who was standing near the farm saw

an immense fireball touch the ground at his feet, but it did him no

damage, but passed, still harmlessly, through a room in the farmhouse

in which there were nine persons. The only effect it produced was the

flaring up of some matches upon the chimney-piece.

It proceeded towards the stables, which were divided into two

compartments. In one there were two cows and two oxen: the first cow,

to the right of the entrance, was killed, the second was uninjured;

the first ox was killed, the second was uninjured.

The same effect was found to have been produced in the other

compartment, in which there were four cows; the first and the third

were killed, the second and fourth were spared: the odd numbers taken

and the even numbers left.

Similar freaks have been recorded in connection with piles of plates

struck by lightning--holes being found in alternate plates. How are

these things to be explained?

The following story is very extraordinary, though it does not help to

clear up the mystery of lightning's strange ways:--

On August 24, 1895, about ten in the morning, in the midst of a storm

of wind and rain, several persons saw descending to the ground a

whitish-coloured globe of about an inch and a half in diameter, which,

on touching the ground, split into two smaller globes. These rose at

once to the height of the chimneys on the houses close by and

disappeared. One went down a chimney, crossed a room in which were a

man and a child, without harming them, and went through the floor,

perforating a brick with a clean round hole of about the size of a

franc. Under this room there was a sheepfold. The shepherd's son,

seated at the doorway, suddenly saw a bright light shining over the

flock of sheep, while the lambs were jumping about in alarm. When he

went up to them, he was startled to discover that five sheep had been

killed. They bore no trace of burning, or of wound of any kind, but

about their lips was a sort of foam, slightly pink in colour.

In the adjoining house, the second fireball had also gone down a

chimney, and had exploded in the kitchen, causing great damage.

In 1890, a young farmer was working on a plot of ground, two or three

miles from Montfort-l'Amaury. A storm breaking out, he stood up

against his horses to take refuge from the rain; moving away a few

yards in order to get his whip, there was seen, when he returned, a

ball of fire almost touching the ear of one of his horses. A moment

later it exploded with a deafening noise. The two horses fell--one of

them unable to get up again. The farmer himself was dashed to pieces.

On other occasions the meteor is hardly more devastating than the

ordinary bomb.

On April 21, at Lanxade, near Bergerac, a storm had been raging

already for some hours, when suddenly--simultaneously with a small

thunderclap--a ball of fire, of the size of the opening of a sack of

corn, fell slowly on one of the banks of the Dordogne, spoiling some

fruit trees, and then crossing the river, it raised a waterspout

several yards high as it went.

It disappeared finally on the other side of a field of corn.

On November 12, 1887, a very curious instance of a fireball was

noticed on the Atlantic.

It was at midnight, near Cape Race. An enormous fireball was seen to

rise slowly out of the sea to the height of sixteen or seventeen

metres. It travelled against the wind, and came quite near the vessel

from which it was being watched. Then it turned towards the south-east

and disappeared. The apparition lasted about five minutes.

In July, 1902, in the course of a violent storm, and immediately after

a loud peal of thunder, a fireball of about the size of a toy balloon

was seen to make its appearance suddenly in the Rue Veron at

Montmartre. After moving along, just above the ground, in front of a

wine-merchant's shop, it exploded like a bomb, most fortunately

without hurting any one, or doing any damage.

The little village of Candes, situated by the confluence of the Vienne

and the Loire, was the scene of the appearance of a fireball in June,

1897. Three persons were sitting in the verandah of a house during a

storm, when they suddenly saw a fireball travelling past them through

the air for a distance of thirty yards or so. Then it exploded with a

loud noise, striking sparks from the ironworks of the verandah. At the

same moment, the servants saw another fireball cross a garden at the

other side of the house, and drop into a small pond. A gardener was

knocked over, but not hurt.

On March 6, 1894, M. Dandois, professor of surgery at the University

of Louvain, went to the neighbouring town of Linden, by railway, to

see a patient. On his return, on foot, the sky suddenly so darkened

over, that he made for the nearest dwelling-place, avoiding, as he did

so, the telegraph poles along the road. Suddenly a ball of fire came

against him and threw him over a ditch into a field, where he lay

unconscious.

A quarter of an hour later, having regained his senses and finding

himself undamaged save for a numbness in one arm and one leg, the

doctor set out again, congratulating himself on the fact that his

umbrella had acted as a sort of portable lightning conductor, for the

steels were all twisted, and showed signs of having borne the brunt of

the fray. Had the handle been of steel also, the electric current

would have run down it into his hand, doubtless, and killed him.

On another occasion a fireball fell upon the door of a house, pushed

it violently open, and made its way into the kitchen.

At the sight of this strange visitor, the cook bolted from the room. A

sempstress, who was at work near the window, received a small burn on

her forehead, of about the size of half a franc, with a slight weal a

couple of inches long--like the tail of a comet.

After bursting, the fireball made its way up the chimney, from which

it removed a mass of soot, smelling somewhat of sulphur.

Here is an instance more curious still--

A violent storm was raging near Marseilles, when seven persons, seated

together in the ground-floor drawing-room of a country house, saw a

fireball as big as a plate appear in their midst.

It directed its course towards a young girl of eighteen, who,

frightened out of her life, had fallen on her knees. Touching her

shoes, it rebounded to the ceiling, then came down to her feet again,

and so on two or three times, with mysterious regularity, the girl

experiencing, it seems, no other sensation than that of a slight cramp

in her legs. Eventually the fireball made its exit from the room

through a keyhole!

The girl could not get up at once after it had gone. For a fortnight

or so she could not walk without assistance, and it was two years

before she got over a liability to sudden weakness in her legs,

causing her suddenly to fall.

It is strange to reflect that these diminutive fireballs, produced by

the actual atmosphere we breathe, are less understood by us than that

enormous globe which we call the sun, and to which is due the

flowering of the entire life of our planet. If we are still in doubt

as to the nature of the sun's spots, at least we have been able to

analyse its own elements. And we know its dimensions, its weight, its

distance from us, its rate of rotation, etc., etc.

Yet these electric spheres that make their escape from the clouds in

times of storm, baffle our investigations altogether.

According to records which seem authentic, fireballs have been seen

actually to come into existence upon the surface of a ceiling, at the

mouth of a well, and upon the flagstones of a church.

In 1713, at the château of Fosdinaro, in the neighbourhood of Massa

Carrara, in the course of a storm and heavy downpour of rain, there

was seen to appear suddenly upon the ground a very vivid flame, white

and blue in colour. It seemed to flare fiercely, but did not move

apparently from the one spot, and after growing quickly in volume it

suddenly disappeared. Simultaneously with its going, one of the

observers felt a curious sort of tickling behind his shoulder, moving

upwards; several bits of plaster from the ceiling under which he stood

fell upon his head, and there was a sudden crash quite unlike an

ordinary thunderclap.

In 1750, on the 2nd of July, at about three in the afternoon, the Abbé

Richard happened to be in the church of St. Michel at Dijon during a

storm. "Suddenly," he tells us, "I saw between two pillars of the nave

a bright red flame floating in the air about three feet above the

floor. Presently it rose to a height of twelve or fifteen feet,

increasing in volume. Then, after having moved some yards to one side,

while still rising diagonally to the height almost of the woodwork of

the organ, it disappeared at last with an explosion like the report of

a cannon."

On July 21, 1745, a violent storm broke out in Boulogne, and the tower

of a convent was struck by a fireball. It was of great size, and was

seen to emerge from one of the sewers of the town and to move along

the surface of the road until it hit against this tower, of which a

part subsided. No one was hurt. A nun affirmed that some years before

she had seen just such another fireball emerge from the same spot and

precipitate itself with a crash against the summit of the tower

without doing any damage.

In the middle of a violent storm, Dr. Gardons saw several fireballs

flying in different directions, not far from the ground, making a

crackling sort of noise. One of them was seen by witnesses to come out

of an excavation full of stagnant water. They killed one man, several

animals, and did much damage to the trees and houses in the vicinity.

In February, 1767, at Presbourg, a blue, conical flame escaped

suddenly with a detonating noise from a brasier, breaking it to

pieces, and scattering the glowing cinders all around. It then went

twisting about the room, burnt the face and hands of a child, escaped

partly through the window, partly through the door, broke into a

thousand pieces a second brasier in another room, and disappeared

finally up a chimney, carrying up with it and discharging from the

chimney-top into the street several hams which had been hung under the

chimney-piece. For several days afterwards the atmosphere of the house

retained a smell of sulphur.

In some cases, fireballs have been seen to come down from the sky

apparently, and then, after almost reaching but not actually touching

the ground, to ascend again. Thus on a hot day in summer 1837, M.

Hapoule, a landed proprietor in the department of the Moselle,

standing in front of the entrance to his stables under the shelter of

a porch during a storm, saw a fireball about the size of an orange

moving in the direction of a dung-heap not far from him. But instead

of going right into it, it stopped about a yard off, and changing its

route, it went off at an angle, keeping the same level for some

distance, when it suddenly seemed to change its mind again, and rose

perpendicularly till it disappeared in the clouds.

These sudden changes, as we have seen, are strangely characteristic of

the habits of fireballs.

The Garde Champêtre of the village of Lalande de Libourne (Gironde)

was traversing the country one evening about half-past ten, engaged in

organizing a _garde de surveillance_, when he suddenly found himself

surrounded by a bright and penetrating light. Astonished, he looked

behind him, and saw a fireball, just broken loose from a cloud,

descending quickly to the ground.

The light vanished presently, but he made his way towards where the

fireball seemed to be falling. When he had gone about two hundred

yards, he saw another brilliant light breaking out from the top of a

tree and spreading itself into a sheaf of rays, every point of which

seemed to emit electric sparks.

At the end of a quarter of an hour the light became weaker, and then

disappeared. The tree was afterwards cut down, and it was found that

the lightning had gone down the centre to a distance of three yards,

and had then passed down outside to the soil, leaving trace of a

semi-circular route; and finally, after rising again on the opposite

side of the tree to a height of four yards, tearing off two narrow

strips of bark, had disappeared. At the foot of the tree a small hole,

about an inch and a quarter in diameter, retained a certain degree of

warmth for an hour and a half afterwards.

Fireballs often keep within the frontiers of cloud-land. They may be

seen passing sometimes from one cloud to another in the high regions

of the atmosphere.

On September 22, 1813, at seven in the evening, M. Louis Ordinaire saw

a fireball leave a cloud at the zenith--the sky being very much

lowering at the time--and go towards another. It was of a

reddish-yellow and extremely brilliant, lighting up the ground with a

bright radiance.

He was able to follow its movements for at least a minute, and then

saw it disappear into the second cloud. There was an explosion

followed by a dull sound like the firing off of a cannon in the

distance.

After a violent storm which broke out near Wakefield on March 1, 1774,

there remained only two clouds in the sky, just above the horizon.

Balls of fire were observed gliding from the higher of the two into

the lower, like falling stars.

In high mountainous districts--in the Alps, for instance--you may

often look down from above upon a storm. It is fascinating thus to

watch the grandiose spectacle of the elements at war. Here from the

pen of Père Lozeran du Fesch is a striking picture of such a scene--

"It was on the 2nd of September, 1716, about three o'clock in the

afternoon. A traveller was making his way down towards Vic from the

summit of Cantal, accompanied by a guide.

"The weather was calm and very warm, but down below, about the middle

of the mountain, a vast sea of mist stretched out in wavelike clouds.

"These clouds were furrowed continually by lightning flashes, some

going quite straight, some zigzag, some taking the shape of fireballs.

When the two men came near this region of clouds, the mist grew so

thick they could hardly see the bridles of their horses.

"The air became gradually more cold and the darkness more dense as

they proceeded downwards. Now they were in the midst of the fireballs

flying in every direction all round them, revolving as they went,

reddish in colour, like saffron lit up.

"They were of all sizes--some quite small on their first appearance,

seeming to grow immensely in volume in a few moments. Drops of rain

fell when they passed. Up to this point the sight had been curious but

not terrifying, but suddenly now, one of these fireballs, about two

feet in diameter, burst open near the traveller and emitted streams

of a bright and beautiful light in every direction, and there was a

dull report followed by a tremendous crash. The two men were much

shaken and the air all round them seemed polluted. After a minute or

two, however, all trace of the explosion had been dissipated, and they

proceeded on their way."

On January 6, 1850, near Merlan, about six in the afternoon, a

fireball burst above the heads of two men, enveloping them in a bluish

light, without hurting them or even damaging their clothes, but giving

them a momentary thrill as from an electric battery. It left no traces

of any kind, not even a smell.

Mr. G. M. Ryan records an instance which he witnessed at Karachi in

Scinde. While in his drawing-room one day with two friends who were

taking refuge from a storm, he rose from his chair and went to the

door to open it, the windows as well as the door being shut at the

time. Returning, he saw in the air and between his friends, a ball of

fire of about the size of a full moon. At the same time there was a

terrible clap of thunder. Two of the spectators were slightly wounded;

one felt a sharp pain on the left side of the face, the other, a

sensation in one arm with a feeling as if his hair were burning. There

was a strong smell of sulphur. In the next room there were two rifles

in a case; one was intact but the other was broken, and there was a

hole in the wall at the point where the muzzle leant against it, and

there were two holes in the same wall a story higher.

On Sunday, August 19, 1900, several people were assembled in a room in

the château of the Baron de France at Maintenay (Pas-de-Calais), when

there was a violent storm raging over the country.

Suddenly there appeared in the midst of the eleven people who were

there, a globe of blue fire about the size of an infant's head, which

quietly crossed the room, touching four people on its way. None of

them were injured. An awful explosion was heard at the moment when the

electric ball disappeared through an open door in front of the great

staircase.

On August 3, 1809, a fireball struck the house of a Mr. David Sutton,

not far from Newcastle-on-Tyne. Eight people were having tea in the

drawing-room when a violent clap of thunder knocked down the chimney.

Immediately after they saw on the ground, at the door opposite the

fireplace, the brilliant visitor which announced itself in the

sonorous voice of Jupiter the thunderer. It remained discreetly at the

entrance of the room, no doubt waiting for the sign to advance. No one

making a move, it came into the middle of the room, and there burst

with a crash, throwing out fiery grains like aeroliths.

The spectacle must have been magnificent--but, we must acknowledge,

rather disquieting.

On September 27, 1772, at Besançon, a voluminous fireball crossed over

a corn-shop and the ward of a hospital full of nurses and children.

This time again the lightning was merciful--it spared nurses and

children, and went and drowned itself in the Doubs.

Nearly thirty years before, in July, 1744, it showed the same regard

for an honest German peasant woman. She was occupied in the kitchen

superintending the family meal, when, after a terrible clap of

thunder, she saw a fireball the size of a fist come down the chimney,

pass between her feet without hurting her, and continue on its course

without burning or even upsetting the spinning-wheel and other objects

on the floor.

Much frightened, the young woman tried to escape; she threw herself

towards the door and opened it, when the fireball at once followed

her, played about her feet, went into the next room, which opened

out-of-doors, crossed it, and through the door into the yard.

It went round the yard, entered a barn by an open door, climbed the

wall opposite, and reaching the edge of the roof, burst with such a

terrific noise that the peasant woman fainted. The barn at once took

fire and was reduced to cinders.

Towards the middle of the last century, March 3, 1835, the steeple of

Crailsheim was set on fire by lightning. The guardian's daughter, aged

twenty years, was at this moment in her room and had her back turned

to the window, when her young brother saw a fireball enter by the

window-sill and descend on to his sister's back, giving her a sudden

shock all over her body. The young girl then saw at her feet a

quantity of small flames, which went towards the kitchen, the door of

which had been opened, and set fire to a pile of mossy wood. There was

no further damage than this attempt at incendiarism, which was easily

extinguished.

Occasionally a fireball seems to take a malignant pleasure in hurling

itself like a fury against lightning conductors; but instead of

quietly impaling itself like the linear lightning, and breathing its

last sigh in a prolonged roar, it struggles, and comes forth

victorious from this curious contest.

There are many cases of fireballs playing about the lightning

conductors without being caught.

In 1777, a fireball shot from the clouds on to the point of the

lightning conductor on the Observatory of Padua. The conductor, which

consisted of an iron chain, was broken at its junction with the stem.

However, it sent on the discharge.

Some years later, in 1792, a huge ball of lightning struck one of the

two conductors on the house of M. Haller at Villiers la Garenne. This

conductor was much injured by the audacious assailant, and so was the

framework of the house; the keen fluid had damaged the metallic

gutters.

At this point I must add that lightning conductors are of recent

creation. Nor would it be surprising if there were defective ones

which could not assure an efficient protection.

However, much later, on December 20, 1845, the same phenomenon was

observed at the château of Bortyvon, near Vire. There, again, the

fireball, ignoring the danger to which it was exposing itself, flung

itself on a lightning conductor placed in the centre of the château.

It was spared, but the château suffered greatly. The electric ball

descended from both sides of the metallic stem, causing a great deal

of damage along its path. On touching the ground it expanded, and many

persons affirm that they saw what was like a huge cask of fire rolling

along the ground.

In truth, ball lightning seems in a certain measure to escape the

influence of lightning conductors.

On September 4, 1903, towards ten o'clock in the evening, M. Laurence

Rotch, director of the Observatory of Blue Hill (U.S.), happening to

be in Paris, made the following curious observation from the

Rond-point of the Champs Elysées.

Looking in the direction of the Eiffel Tower, he saw the summit of the

edifice struck by white lightning coming from the zenith. At the same

moment a fireball, less dazzling than the lightning, slowly descended

from the summit to the second platform. It appeared to be about one

yard in diameter, and to be situated in the middle of the tower,

taking less than two seconds to cover a distance of about 100 yards.

Then it disappeared. The next day the observer ascertained, on

visiting the tower, that it had actually been struck by lightning

twice on the previous day.

It is to be noted that the meteor did not follow the conductor; but,

after all, is not the whole tower itself the most powerful conductor

imaginable? Would not the enormous masses of iron used in its

construction neutralize the attraction of the thin metallic rods,

effectual for the protection of ordinary buildings, but incapable, one

would think, of competing with the attractive force of this immense

metallic framework?

Here are some cases where globular lightning has struck bells or

telegraph wires, which it has followed with docility.

Several times it has been seen poised like a bird on a telegraph wire

near a railway-station, and has then quietly disappeared.

[Illustration: THE EIFFEL TOWER AS A COLOSSAL LIGHTNING CONDUCTOR.

Photograph taken June 3, 1902, at 9.20 p.m., by M. G. Loppé. Published

in the _Bulletin de la Société Astronomique de France_ (May, 1905)]

We see that it is not absolutely inimical to points, nor to metals,

but it prefers its independence, and he must get up early who would

catch it in a snare.

It is an anarchist--it acknowledges no rule.

But we must confess that if spheroidal lightning seems particularly

capricious, it is because we are still ignorant of the laws which

guide it. Our ignorance alone is the cause of the mystery.

We try to discover the enigma in the silence of the laboratories,

where physicians question science without ceasing; we try to reproduce

fireballs artificially, but the problem is complicated, and its

solution presents enormous difficulties.

Hypotheses are not wanting. Some years ago, M. Stéphane Leduc recorded

an interesting experiment, producing a moving globular spark.

When two very fine and highly polished metallic points, each in

affinity with one of the poles of an electro-static machine, rest

perpendicularly on the sensitive face of a gelatine bromide of silver

photographic plate, which is placed on a metallic leaf, the two points

being 5 to 10 centimetres the one from the other, an effluvium is

produced round the positive point, while at the negative point a

luminous globule is formed.

When this globule has reached a sufficient size, you can see it detach

itself from the point, which ceases to be luminous, begin to move

forward slowly on the plate, make a few curves, and then set off for

the positive point; when it reaches this, the effluvium is

extinguished, all luminous phenomenon ceases, and the machine acts as

if its two poles were united by a conductor.

The speed with which the luminous globe moves is very slight. It takes

from one to four minutes to cover a distance of 5 to 6 centimetres.

Sometimes, before reaching the positive point, the globe bursts into

two or more luminous globules, which individually continue their

journey towards the positive point.

On developing the plate, you will find traced on it the route followed

by the globule, the point of explosion, the routes resulting from the

division, the effluvium round the positive point. Also, if you stop

the experiment before the arrival of the globule at the positive

point, the photograph will only give the route to that point.

The globule makes its course the conductor. If during its journey you

were to throw powder on the plate--sulphur, for example--the course it

followed will be marked by a line of little aigrettes, looking like a

luminous rosary.

Of all the known electric phenomena, this is the most analogous with

globular lightning.

[Illustration: PHOTOGRAPH OF THE POSITIVE POLE OF AN ELECTRIC SPARK.]

[Illustration: PHOTOGRAPH OF THE NEGATIVE POLE OF AN ELECTRIC SPARK.]

But the really complicated part of the question is when ball

lightning loses part of its fluidity and becomes a semi-solid body, as

in the following instance:--

On April 24, 1887, a storm burst over Mortrée (Orne), and the

lightning literally chopped the telegraph wire on the route to

Argentan for a distance of 150 yards. The pieces were so calcinated

that they might have been under the fire of a forge; some of the

longer ones were bent and their sections welded together. The

lightning entered by the door of a stable in the form of a fireball,

and came near a person who was preparing to milk a cow; then it

_passed between the legs of the animal_, and disappeared without

causing any damage. The terrified cow raised itself on its hind legs

with frantic bellowing, and its master ran away, frightened out of his

wits, but there was no harm done.

The inexplicable phenomenon was that at the precise moment when the

lightning crossed the stable, a great quantity of incandescent stones

fell before a neighbouring house. "Some of these fragments, of the

size of nuts," wrote the Minister of Post and Telegraphs at the

Academy, "are of a not very thick material, of a greyish-white, and

easily broken by the fingers, giving forth a characteristic odour of

sulphur. The others, which are smaller, are exactly like coke.

"It would perhaps be useful to say here, that during this storm the

thunderclaps were not preceded by the ordinary muttering, they burst

quickly like the discharge of musketry, and succeeded one another at

short intervals. Hail fell in abundance, and the temperature was very

low."

It is only by a semblance of disbelief that one can get the peasants

to tell us the stories of what they pretend to have seen of the fall

of aeroliths during storms. They have christened the uranoliths

"thunder-stones."

These substances have evidently no relation to uranoliths, but they

prove none the less that ponderable matter may accompany the fall of

lightning.

Here are two more examples--

In the month of August, 1885, a storm burst over Sotteville

(Seine-Inférieure); lightning furrowed the sky, the thunder muttered,

and the rain fell in torrents. Suddenly, in the Rue Pierre Corneille,

several small balls, about the size of a common pea, were seen to

fall; these burned on touching the ground, sending out a little violet

flame. People counted more than twenty, and one of the spectators, on

putting her foot on one of them, produced a fresh flame. They left no

trace on the ground.

On August 25, 1880, in Paris, during a rather violent storm, in broad

daylight, M. A. Trécul, of the Institute, saw a very brilliant

voluminous body, yellowish-white, and rather long in shape, being

apparently 35 to 40 centimetres in length, by about 25 in width, with

slightly conical ends.

This body was only visible for a few seconds; it seemed to disappear

and re-enter a cloud, but in departing--and this is the chief

point--it dropped a little substance, which fell vertically like a

heavy body under the sole influence of gravity. It left a trail of

light behind it, at the edges of which could be seen sparks, or rather

red globules, because their light did not flash. Near the falling

substance the luminous trail was almost vertical, while in the further

part it was sinuous. The small substance divided in falling, and the

light went out soon after, when it was on the point of reaching the

tops of the houses. When it was disappearing, and at the moment of the

division, no noise was heard, although the cloud was not far away.

This fact incontestably proves the presence of ponderable matter in

clouds, which is not violently projected by an explosion in the bolis,

nor accompanied by a noisy electric discharge.

We are still far from understanding the interesting problem of the

formation and nature of ball lightning. Instead of denying it, men of

science ought to study it, because it is certainly one of the most

remarkable of the curiosities of atmospheric electricity.

We must begin by finding out the exact facts, which are extraordinary

enough to captivate our attention. The theories will follow.

Thunder and Lightning · 第 4 / 10 章