|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Franklin and De Romas
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CHAPTER XXXVIII
FRANKLIN AND DE ROMAS
[165]
HE next day Claire and her two brothers could talk of
nothing but the experiments of the evening before. It was
their subject of conversation the whole morning. The cat's
beads of fire and the flashes from the paper had greatly
impressed them; so their uncle, in order to profit by this
awakening of their attention, resumed as soon as possible
his instructive talk.
"I am sure you are all three asking yourselves why, before
telling you about thunder, I rubbed sealing-wax, a strip of
paper, and the cat's back. You shall know, but first of all
listen to a little story.
"More than a century ago a magistrate of the little town of
Nérac, named de Romas, devised the most momentous
experiment ever registered in the annals of science. One day
he was seen going out into the country in a storm, with an
enormous paper kite and a ball of twine. Over two hundred
persons, keenly interested, accompanied him. What in the
world was that celebrated magistrate going to do?
Forgetful
of his grave functions, did he propose some diversion
unworthy of him? Was it to witness a puerile kite-flying
that these curious ones flocked from all points of the town?
No, no; de Romas was about to realize the most audacious
project that man's
[166] genius has ever conceived; his bold
purpose was to evoke the thunderbolt from the very depths of
the clouds, and to call down fire from heaven.
"The kite that was to draw the thunderbolt from the midst of
the storm-clouds and bring it into the intrepid
experimenter's view did not differ from those familiar to
you; only the hemp cord had through its entire length a
copper thread. The wind having risen, the paper contrivance
was thrown into the air and attained a height of about two
hundred meters. To the lower end of the cord was attached a
silk string, and this string was made fast under the stoop
of a house, to shelter it from the rain. A little tin
cylinder was hung to the hempen cord at one point and in
touch with the metallic thread running through the cord.
Finally, de Romas was furnished with a similar cylinder that
had at one end a long glass tube as handle. It was with this
instrument or this exciter, held in his hand by the glass
handle, that he was to make the fire dart from the clouds,
conducted by the copper thread of the kite to the metallic
cylinder at the end of this thread. The silk cord and the
glass handle served to prevent the passage of the
thunderbolt, either into the ground or into the exciter's
arm; for these substances have the property of not giving
passage to electricity unless it is too strong. Metals, on
the contrary, let it circulate freely.
"Such was the simple arrangement of the apparatus invented
by de Romas to verify his audacious prevision. What is to be
expected from this child's plaything thrown into the air to
meet the
[167] thunder? Does it not seem to you foolish to suppose
that such a plaything can direct the thunderbolt and master
it? The magistrate of Nérac must, however, by wise
meditations on the nature of thunder, have acquired the
certainty of success, to dare thus, before hundreds of
witnesses, to undertake this attempt, the failure of which
would cover him with confusion. The result of this terrible
conflict between thought and thunder cannot be in doubt:
thought, as always, when well directed, will gain the upper
hand.
"Behold, now, the clouds, forerunners of the storm, are
coming near the kite. De Romas moves the exciter toward the
tin cylinder suspended at the end of the cord, and suddenly
there is a flash of light. It is produced by a dazzling
spark which darts upon the exciter, crackles, emits a flash
of lightning, and immediately disappears."
"That is just what we got yesterday evening," observed Jules,
"when we put the end of a key near the strip of warmed and
rubbed paper; it is what the cat's back showed us when it
was stroked with the hand."
"The very same thing," replied his uncle. "Thunder, beads of
fire from the cat, sparks from paper—all are due to
electricity. But let us return to de Romas. We see that
there is electricity, the thunderbolt in miniature, in the
kite's string. It is inoffensive yet, on account of its
feeble quantity; so de Romas does not hesitate to draw it
forth with his finger. Every time he brings his finger near
the cylinder, he draws a spark like that received by the
[168] exciter. Emboldened by his example, the spectators draw near
and evoke the electric explosion. They crowd around the
wonderful cylinder that now contains the fire from heaven,
called down by man's genius; each one wishes to call forth
the lightning, and each wishes to see sparkle between his
fingers the fulminant substance descended from the clouds.
So they play with the thunder for half an hour with
impunity, when all at once a violent spark reaches de Romas
and almost knocks him over. The hour of peril has come. The
storm is getting nearer, stronger, every moment; thick
clouds hover over the kite.
"De Romas summons up all his firmness; he quickly makes the
crowd draw back and remains alone at the side of his
apparatus, in the middle of the circle of spectators, who
are beginning to get frightened. Then, with the aid of the
exciter, he elicits from the metallic cylinder first strong
sparks, capable of throwing a person down under the violence
of the commotion, then ribbons of fire that dart in
serpentine lines and burst with a crash. These ribbons soon
measure a length of two or three meters. Any one struck by
one of them would certainly perish. De Romas, fearing from
moment to moment some fatal accident, enlarges the circle of
curious spectators and ceases the perilous provocation of
electric fire. But, braving imminent death, he continues his
perilous observations at close range, with this same
coolness as if he were engaged in the most harmless
experiment. Around him there is heard a roaring like the
continuous blast of a forge; an odor
[169] of burning is in the
air; the kite-string is covered with a luminous envelope and
forms a ribbon of fire joining heaven to earth. Three long
straws, lying by chance on the ground, start up, jump,
spring toward the string, fall, spring up again, and for
some minutes entertain the spectators with their disordered
evolutions."
"Last evening," Claire remarked, "the down of the feathers
and the little pieces of paper jumped in the same way
between the electrified sheet of paper and the table."
"That is quite natural," said Jules, "since Uncle has just
told us that the rubbed sheet of paper takes to itself the
very essence of thunder, only in a very small quantity."
"I am glad to see you grasp the close resemblance between
thunder and the electricity that we produce by rubbing
certain bodies. De Romas made his perilous experiment on
purpose to prove that resemblance. I said perilous
experiment; you will see, in fact, what danger the audacious
experimenter ran. Three straws, I told you, were jumping
from the string to the ground, and from the ground to the
string, when all at once everybody turned pale with fright:
there came a violent explosion and a thunderbolt fell,
making a large hole in the ground and raising a cloud of
dust."
"My goodness!" gasped Claire. "Was de Romas killed?"
"No, de Romas was safe and beaming with joy: his previsions
were verified with a success that bordered on the
prodigious: it was demonstrated that a
[170] thunderbolt can be
brought from the clouds within reach of the observer; he had
proved that electricity is the cause of thunder. That, my
children, was no trivial result, fit only to satisfy our
curiosity: the nature of thunder being ascertained, it
became possible to secure protection from its ravages, as I
will tell you in the story of the lightning-conductor."
"De Romas, who made these important experiments at the peril
of his life, must have been loaded with honors and riches by
his contemporaries," said Claire.
"Alas! my dear child," replied her uncle, "things do not
commonly happen that way. Truth rarely finds any free spot
in which to plant itself; it has to fight against prejudice
and ignorance. The battle is sometimes so painful, that men
of strong will succumb to the task. De Romas, wishing to
repeat his experiment at Bordeaux, was stoned by the mob,
who saw in him a dangerous man evoking thunder by his
witchcraft. He was obliged to flee in haste, abandoning his
apparatus.
"A short time before de Romas, in the United States of North
America, Franklin made similar researches on the nature of
thunder. Benjamin Franklin was the son of a poor
soap-manufacturer. He found at home merely the requisite
means for learning to read, write, and cipher; and yet he
became by his learning one of the most remarkable men of his
time. One stormy day in 1752 he went into the country near
Philadelphia, accompanied by his son, who carried a kite
made of silk tied at the four corners to two little glass
rods. A metal tail
termi- [171] nated the apparatus. The kite was
thrown up toward a storm-cloud. At first nothing happened to
confirm the learned American's previsions: the string gave
no sign of electricity. Rain came on. The wet string let the
electricity circulate more freely; and Franklin, without
thinking of the danger he ran, and transported with joy at
thus stealing its secret from the thunder, elicited with his
finger a shower of sparks strong enough to set fire to
spirits of wine."
|