“What takes place at the expense of a plate of water, and of the
moisture of the soil or wet linen, takes place also, on a vast scale,
over the entire surface of the earth. The air is in contact with damp
soil, with innumerable sheets of water, lakes, marshes, streams, rivers,
brooks, above all with the sea, the immense sea, which presents thrice
as much surface as the dry land. The great drinker, as Jules calls it,
the air, must therefore drink to satiety and everywhere and always
contain moisture, sometimes more, sometimes less, according to the heat.

“The air that is around us now, that invisible air in which the eye
distinguishes nothing, nevertheless contains water that can be made
visible. The means is very simple; all that is necessary is to cool the
air a little. When you squeeze a wet sponge with the hand, you make
water ooze out of it. Cold acts on moist air very much as the pressure
of the hand on the sponge: it causes the moisture to distil in the form
of minute drops. If Claire will go to the pump and fill a bottle with
very cold water, I will show you this curious experiment.”

Claire went to the kitchen and came back with a bottle full of the
coldest water possible. Her uncle took the bottle, wiped it well with
his handkerchief so that no trace of moisture should remain on the
outside, and put it on an equally well-wiped plate.

Now the bottle, at first perfectly clear, becomes covered with a kind of
fog which tarnishes its transparency: then little drops appear, run down
its sides, and fall into the plate. At the end of a quarter of an hour
there was enough water accumulated in the plate to fill a thimble.

“The drops of water now running down the outside of the bottle,” Uncle
Paul explained, “do not come, it is very clear, from the inside, for
glass cannot be pierced by water. They come from the surrounding air,
which cools off on touching the bottle and lets its moisture distil. If
the bottle were colder, if full of ice, the deposit of liquid drops
would be more abundant.”

“The bottle reminds me of something of the same kind,” said Claire.
“When you fill a perfectly clean glass with very cold water, the outside
of the glass immediately tarnishes and looks as if badly washed.”

“That again is the surrounding air depositing its moisture on the cold
side of the glass.”

“Is that invisible moisture contained in the air abundant?” asked Jules.

“The invisible vapor of the air is always a thing so subtle, so
disseminated, that it would take enormous volumes to make a small
quantity of water. During the heat of summer, when the air holds the
most vapor, it takes 60,000 liters of moist air to furnish one liter of
water.”

“That is very little,” was Jules’s comment.

“It is a great deal if one thinks of the immense volume of the
atmosphere,” replied his uncle, and then added:

“The experiment of the bottle teaches us two things: first, there is
always invisible vapor in the air; in the second place, this vapor
becomes visible and changes into fog, then into drops of water, by
cooling. This return of invisible vapor to visible vapor or fog, then to
a state of water, is called condensation. Heat reduces water to
invisible vapor, and cold condenses this vapor, that is to say brings it
back to a liquid state or at least to the state of visible vapor or fog.
We will have the rest this evening.”

                              CHAPTER XLIV

                                  RAIN

“THE explanations of this morning account for the formation of clouds. A
continual evaporation takes place on the surface of the damp earth as
well as on the surface of the different sheets of water, lakes, ponds,
marshes, streams, and above all the sea. The vapors formed rise into the
air and remain invisible as long as the heat is sufficient. But since
heat diminishes as the height increases, there comes a time when the
vapors can no longer be kept in complete solution, and they condense
into a mass of visible vapor, into a fog or cloud.

“When, after a chill encountered in the upper strata of the atmosphere,
the cloud-mist reaches a certain degree of condensation, little drops of
water form and fall in rain. At first very small, they increase in
volume on the way by the union of other similar little drops. Their size
on reaching us is proportioned to the height from which they fell, but
never exceeds the limits suitable to the part rain is intended to play.
If too large, the rain-drops would fall heavily on the plants they are
to water, and would lay them flat on the ground, dead. And what would
happen if the condensation of vapor, instead of taking place gradually,
should be sudden? There would no longer descend from heaven rain-drops,
but heavy columns of water, which, in their fall, would strip the trees
of their branches, crush the harvests, and make the roofs of our houses
fall in. But, far from taking this devastating form, rain falls in drops
as if passed through a sieve placed by design in its passage to divide
it and weaken the shock. On rare occasions, it is true, rain does reach
us under so strange a disguise as to strike the ignorant with terror.
Who would not be frightened when it rains blood or sulphur?”

“What do you say, Uncle?” interrupted Emile; “rains blood or sulphur?
For my part, I should be dreadfully afraid.”

“I too,” said Claire.

“Is that true?” Jules asked, in his turn.

“True. You know well I only tell you true stories. There are rains of
blood and sulphur, at least in appearance. It is proved that showers
have been seen of which the drops left on the walls, roads, leaves of
the trees, and clothes of passers-by, are red spots like blood. At other
times, with the rain, there has fallen from the sky a fine dust, of a
beautiful yellow, resembling sulphur. Did it really rain blood, sulphur?
No. This so-called rain of blood or sulphur, causing foolish alarms, is
ordinary rain stained with various sorts of dust raised from the ground
by the wind. In the spring when, in mountainous countries, immense
forests of fir-trees are in blossom, every breath of wind carries clouds
of a fine yellow dust contained in the little flowers of the fir-tree.
You can see a similar dust in all flowers, especially the lily.”

“It is that dust that daubs your nose yellow when you smell a lily too
close,” declared Jules.

“Exactly. It is called pollen. Well, in falling at a distance, sometimes
alone, sometimes accompanied by rain, the pollen gathered up from the
forests by a breath of wind causes the so-called sulphur-rain.”

“Your rain of blood or sulphur isn’t at all terrifying,” Claire
remarked.

“Of course not; and yet whole populations have their hearts frozen with
fear at the inoffensive fall of a whirlwind of pollen or red dust. They
believe themselves visited with plagues, precursors of the end of the
world. Ignorance is a pitiful thing, my dear children, and knowledge is
a fine thing, even if it only served to deliver us from stupid terrors.”

“In future,” said Jules, stoutly, “it can rain sulphur or blood; if any
one is afraid, it will not be I.”

“There can also fall from the sky, with or without rain, various mineral
substances, such as sand, for example, or powdered chalk, or dust from
the roads. There is even mention of showers of small animals,
caterpillars, insects, and very young toads. The marvelous feature of
these rains disappears if one considers that a violent blast of wind can
carry with it all light substances encountered in its course, and can
transport them long distances before letting them fall again.

“At other times a rain of insects is due to something else besides
transportation by the wind. Some kinds of grasshoppers, for example,
gather together in immense swarms to go to another district when
nutriment fails them. The emigrating band flies, as at a given signal,
and passes through the air in the form of a great cloud that intercepts
the daylight. The migration continues for days at a time, so numerous is
the host. Then the voracious swarm alights, like a living storm, on the
vegetation of some distant province. In a few hours grass, leaves of
trees, grain, prairies—everything is browsed. The soil, as if ravaged by
fire, hasn’t a blade of grass left. Sometimes the people of Algeria die
of hunger. The grasshopper has devoured their harvests.

“Volcanoes cause cinder-showers. Volcanic ashes is the name given to the
calcined dust thrown up to a great height by volcanoes at the moment of
their eruption. These powdered substances form enormous clouds, which
produce in the daytime a darkness like that of the darkest nights, and
which, falling to earth at a greater or less distance, stifle animals
and plants under their showers of dust.”

                              CHAPTER XLV

                               VOLCANOES

“IT is not late yet, Uncle,” said Jules; “you ought to tell us about
those terrible mountains, those volcanoes that the showers of ashes come
from.”

At the word “volcano,” Emile, who was already asleep, rubbed his eyes
and became all attention. He too wanted to hear the great story. As
usual, their uncle yielded to their entreaties.

“A volcano is a mountain that throws up smoke, calcined dust, red-hot
stones, and melted matter called lava. The summit is hollowed out in a
great excavation having the shape of a funnel, sometimes several leagues
in circumference. That is what we call the crater. The bottom of the
crater communicates with a tortuous conduit or chimney too deep to
estimate. The principal volcanoes of Europe are: Vesuvius, near Naples;
Etna in Sicily; Hecla in Iceland. Most of the time a volcano is either
in repose or throwing up a simple plume of smoke; but from time to time,
with intervals that may be very long, the mountain grumbles, trembles,
and vomits torrents of fiery substances. It is then said to be in
eruption. To give you a general idea of the most remarkable phenomena
attending volcanic eruption, I will choose Vesuvius, the best known of
the European volcanoes.

“An eruption is generally announced beforehand by a column of smoke that
fills the orifice of the crater and rises vertically, when the air is
calm, to nearly a mile in height. At this elevation it spreads out in a
sort of blanket that intercepts the sun’s rays. Some days before the
eruption the column of smoke sinks down on the volcano, covering it with
a big black cloud. Then the earth begins to tremble around Vesuvius;
rumbling detonations under the ground are heard, louder and louder each
moment, soon exceeding in intensity the most violent claps of thunder.
You would think you heard the cannonades of a numerous artillery
detonating ceaselessly in the mountain’s sides.

“All at once a sheaf of fire bursts from the crater to the height of
2000 or 3000 meters. The cloud that is floating over the volcano is
illumined by the redness of the fire; the sky seems inflamed. Millions
of sparks dart out like lightning to the top of the blazing sheaf,
describe great arcs, leaving on their way dazzling trails, and fall in a
shower of fire on the slopes of the volcano. These sparks, so small from
a distance, are incandescent masses of stone, sometimes several meters
in dimension, and of a sufficient momentum to crush the most solid
buildings in their fall. What hand-made machine could throw such masses
of rock to such heights? What all our efforts united could not do even
once, the volcano does over and over again, as if in play. For whole
weeks and months these red blocks are thrown up by Vesuvius, in numbers
like the sparks of a display of fireworks.”

“It is both terrible and beautiful,” said Jules. “Oh! how I should like
to see an eruption, but far off, of course.”

“And the people who are on the mountain?” questioned Emile.

“They are careful not to go on the mountain at that time; they might
lose their lives, suffocated by the smoke or crushed by the shower of
red-hot stones.

“Meantime, from the depths of the mountain, through the volcanic
chimney, ascends a flux of melted mineral substance, or lava, which
pours out into the crater and forms a lake of fire as dazzling as the
sun. Spectators who, from the plain, anxiously follow the progress of
the eruption, are warned of the coming of the lava-flood by the
brilliant illumination it throws on the volumes of smoke floating in the
upper air. But the crater is full; then the ground suddenly shakes,
bursts open with a noise of thunder, and through the crevasses as well
as over the edges of the crater the lava flows in streams. The fiery
current, formed of dazzling and paste-like matter similar to melted
metal, advances slowly; the front of the lava-stream resembles a moving
rampart on fire. One can flee before it, but everything stationary is
lost. Trees blaze a moment on contact with the lava and sink down,
reduced to charcoal; the thickest walls are calcined and fall over; the
hardest rocks are vitrified, melted.

“The flow of lava comes to an end, sooner or later. Then subterranean
vapors, freed from the enormous pressure of the fluid mass, escape with
more violence than ever, carrying with them whirlwinds of fine dust that
floats in sinister clouds and sinks down on the neighboring plain, or is
even carried by the winds to a distance of hundreds of leagues. Finally,
the terrible mountain calms down, and peace is restored for an
indefinite time.”

“If there are towns near the volcanoes, cannot those streams of fire
reach them? Cannot those clouds of ashes bury them?” asked Jules.

“Unfortunately all that is possible and has happened. I will tell you
about it to-morrow, for it is time to go to bed now.”

                              CHAPTER XLVI

                                CATANIA

“YESTERDAY,” Uncle Paul resumed, “Jules asked me if the lava-streams
could not reach towns situated near volcanoes. The following story will
answer his question. It is about an eruption of Mount Etna.”

“Etna is that volcano in Sicily where the big chestnut tree of a hundred
horses is?” asked Claire.

“Yes. I must tell you that two hundred years ago there occurred in
Sicily one of the most terrible eruptions on record. During the night,
after a furious storm, the earth began to tremble so violently that a
great many houses fell. Trees swayed like reeds shaken by the wind;
people, fleeing distracted into the country to avoid being crushed under
the ruins of their buildings, lost their footing on the quaking ground,
stumbled, and fell. At that moment Etna burst in a fissure four leagues
long, and along this fissure rose a number of volcanic mouths, vomiting,
amid the crash of frightful detonations, clouds of black smoke and
calcined sand. Soon seven of these mouths united in an abyss that for
four months did not cease thundering, glowing, and throwing up cinders
and lava. The crater of Etna, at first quite at rest, as if its furnaces
had no connection with the new volcanic mouths, woke up a few days after
and threw to a prodigious height a column of flames and smoke; then the
whole mountain shook, and all the crests that dominated its crater fell
into the depths of the volcano. The next day four mountaineers dared to
climb to the top of Etna. They found the crater very much enlarged by
the falling-in of the day before: its orifice, which before had measured
one league, now measured two.

“In the meantime, torrents of lava were pouring from all the crevasses
of the mountain down upon the plain, destroying houses, forests, and
crops. Some leagues from the volcano, on the seacoast, lies Catania, a
large town surrounded then by strong walls. Already the liquid fire had
devoured several villages, when the stream reached the walls of Catania
and spread over the country. There, as if to show its strength to the
terrified Catanians, it tore a hill away and transported it some
distance; it lifted in one mass a field planted with vines and let it
float for some time, until the green was reduced to charcoal and
disappeared. Finally, the fiery stream reached a wide and deep valley.
The Catanians believed themselves saved: no doubt the volcano would
exhaust its strength by the time it covered the vast basin which the
lava had just entered. But what an error of judgment! In the short space
of six hours, the valley was filled, and the lava, overflowing, advanced
straight toward the town in a stream half a league wide and ten meters
high. It would have been all over with Catania if, by the luckiest
chance, another current, whose direction crossed the first, had not come
and struck against the fiery flood and turned it from its course. The
stream, thus turned, coasted the ramparts of the town within
pistol-shot, and turned toward the sea.”

“I was very much afraid for those poor Catanians,” interposed Emile,
“when you spoke of that wall of fire, high as a house, going straight
toward the town.”

“All is not over yet,” his uncle proceeded. “The stream, I told you, was
going toward the sea. There was, then, a formidable battle between the
water and the fire. The lava presented a perpendicular front of 1500
meters in extent and a dozen meters high. At the touch of that burning
wall, which continued plunging further and further into the waves,
enormous masses of vapor rose with horrible hissings, darkened the sky
with their thick clouds, and fell in a salt rain over all the region. In
a few days the lava had made the limits of the shore recede three
hundred meters.

“In spite of that, Catania was still menaced. The stream, swollen with
new tributaries, grew from day to day and approached the town. From the
top of the walls the inhabitants followed with terror the implacable
progress of the scourge. The lava finally reached the ramparts. The
fiery flood rose slowly, but it rose ceaselessly; from hour to hour it
was found to have risen a little higher. It touched the top of the
walls, whereupon, yielding to the pressure, they were overthrown for the
length of forty meters, and the stream of fire penetrated the town.”

“My goodness!” cried Claire. “Those poor people are lost?”

“No, not the people, for lava runs very slowly, on account of its sticky
nature, and one can be warned in time; it was the town itself that ran
the greatest risk. The quarters invaded by the lava were the highest;
from there the current could spread everywhere. So Catania seemed
destined to total destruction, when it was saved by the courage of some
men who attempted to battle with the volcano. They bethought themselves
to construct stone walls, which, placed across the route of the
on-coming stream, would change its direction. This device partly
succeeded, but the following was the most efficacious. Lava streams
envelop themselves in a kind of solid sheath, embank themselves in a
canal formed of blocks coagulated and welded together. Under this
covering the melted matter preserves its fluidity and continues its
ravaging course. They thought, then, that by breaking these natural
dikes at a well-chosen spot, they would open to the lava a new route
across country and would thus turn it from the town. Followed by a
hundred alert and vigorous men, they attacked the stream, not far from
the volcano, with blows of iron bars. The heat was so great that each
worker could strike only two or three blows in succession, after which
he withdrew to recover his breath. However, they managed to make a
breach in the solid sheath, when, as they had foreseen, the lava flowed
through this opening. Catania was saved, not without great loss, for
already the lava flood had consumed, within the town walls, three
hundred houses and some palaces and churches. Outside of Catania, this
eruption, so sadly celebrated, covered from five to six square leagues
with a bed of lava in some places thirteen meters thick, and destroyed
the homes of twenty-seven thousand persons.”

“Without those brave men who did not hesitate, at the risk of being
burnt alive, to go and open a new passage for the stream of fire,
Catania would certainly have been lost,” remarked Jules.

“Catania would have been all burnt down, there is no doubt. To-day its
calcined ruins would be buried under a bed of cold lava, and there would
be nothing left but the name of the large town that had disappeared.
Three or four stout-hearted men revive the courage of the terrified
population; they hope that heaven will aid them in their devotion, and,
ready to sacrifice their lives, they prevent the frightful disaster. Ah!
may God give you grace, my dear child, to imitate them in the time of
danger; for, you see, if man is great through his intelligence, he is
still greater through his heart. In my old age, when I hear you spoken
of, I shall be more gladdened by the good you may have done than by the
knowledge you may have acquired. Knowledge, my little friend, is only a
better means of aiding others. Remember that well, and when you are a
man bear yourself in danger as did those of Catania. I ask it of you in
return for my love and my stories.”

Jules furtively wiped away a tear. His uncle perceived that he had sown
his word in good ground.

                             CHAPTER XLVII

                           THE STORY OF PLINY

“TO teach you what the cinders thrown up by a volcano can do, I am now
going to tell you a very old story, just as it was transmitted to us by
a celebrated writer of those old times. This writer is called Pliny. His
writing is in Latin, the great language of those days.

“It was in the year 79 of our era. Contemporaries of our Savior were
still living. Vesuvius was then a peaceful mountain. It was not
terminated then, as to-day, by a smoking cone, but by a table-land
slightly concave, the remains of an old filled-up crater where thin
grasses and wild vines grew. Very fertile crops covered its sides; two
populous towns, Herculaneum and Pompeii, lay stretched at its base.

“The old volcano, which seemed forever lulled, and whose last eruptions
went back to times beyond the memory of man, suddenly awakened and began
to smoke. On the 23d of August, about one o’clock in the afternoon, an
extraordinary cloud, sometimes white, sometimes black, was seen hovering
over Vesuvius. Impelled violently by some subterranean force, it first
rose straight up in the form of a tree-trunk; then, after attaining a
great height, it sank down under its own weight and spread out over a
wide area.

“Now, there was at that time at Messina, a seaport not far from
Vesuvius, an uncle of the author who has handed down these things to us.
He was called Pliny, like his nephew. He commanded the Roman fleet
stationed at this port. He was a man of great courage, never retreating
from any danger if he could gain new knowledge or render aid to others.
Surprised at the singular cloud that hovered over Vesuvius, Pliny
immediately set out with his fleet to go to the aid of the menaced coast
towns and to observe the terrible cloud from a nearer point. The people
at the foot of Vesuvius were fleeing in haste, wild with fear. He went
to the side where all were in flight and where the peril appeared the
greatest.”

“Fine!” cried Jules. “Courage comes to you when you are with those who
are not afraid. I love Pliny for hastening to the volcano to learn about
the danger. I should like to have been there.”

“Alas! my poor child, you would not have found it a picnic. Burning
cinders mixed with calcined stones were falling on the vessels; the sea,
lashed to fury, was rising from its bed; the shore, encumbered with
debris from the mountain, was becoming inaccessible. There was nothing
to do but retreat. The fleet came to land at Stabiæ, where the danger,
still distant, but all the time approaching, had already caused
consternation. In the meantime, from several points on Vesuvius great
flames burst forth, their terrifying glare rendered more frightful by
the darkness caused by the cloud of cinders. To reassure his companions
Pliny told them that these flames came from some abandoned villages
caught by the fire.”

“He told them that to give them courage,” Jules conjectured, “but he
himself well knew the truth of the matter.”

“He knew it well, he knew the danger was great; nevertheless, overcome
by fatigue, he fell into a deep sleep. Now, while he slept, the cloud
reached Stabiæ. Little by little the court leading to his apartment was
filled with cinders, so that in a short time he would not have been able
to get out. They woke him to prevent his being buried alive and to
deliberate on what was to be done. The houses, shaken by continual
shocks, seemed to be torn from their foundations; they swayed from side
to side. Many fell. It was decided to put to sea again. A shower of
stones was falling—small ones, it is true, and calcined by the fire. As
a protection from them, the men covered their heads with pillows, and
going through the most horrible darkness, hardly relieved by the light
of the torches they carried, they made their way toward the shore. There
Pliny sat on the ground a moment to rest, when violent flames,
accompanied by a strong smell of sulphur, put everybody to flight. He
rose and then instantly fell back dead. The emanations, cinders, and
smoke from the volcano had suffocated him.”

“Poor Pliny! To be stifled to death like that by the horrible mountain,
and he so courageous!” lamented Jules.

“Whilst the uncle was dying at Stabiæ, the nephew, left at Messina with
his mother, was witness of what he relates to us. ‘The night after my
uncle’s departure,’ he tells us, ‘the earth began to tremble violently.
My mother hastened in alarm to waken me. She found me getting up to go
and waken her. As the house threatened to collapse, we sat outside in
the court, not far from the sea. With the carelessness of youth—I was
then eighteen—I began to read. A friend of my uncle’s came along. Seeing
my mother and me both of us seated, and me with a book in my hand, he
blamed us for our confidence and induced us to look out for our safety.
Although it was seven o’clock in the morning, we could hardly see, the
air was so obscured. At times buildings were so shaken that their fall
was imminent at any moment. We followed the example of the rest and left
the town. We stopped some distance off in the country. The wagons that
were brought away swayed continually with the shaking of the ground.
Even with their wheels blocked with stones they could hardly be held in
place. The sea flowed back on itself: driven from the shore by the
earthquake shocks, it receded from the beach and left a multitude of
fish dry on the sand. A horrible black cloud came toward us. On its
flanks were serpentine lines of fire like immense flashes of lightning.
Soon the cloud descends, covering earth and sea. Then my mother begs me
to flee with all the speed of my youth, and not to expose myself to
imminent death by adapting my pace to hers, weighed down as she was by
years. She would die content if she knew I was out of danger.’”

“And Pliny left his old mother behind in order to get away the faster?”
queried Jules.

“No, my child, he did what you would all have done. He remained,
sustaining and encouraging her, resolved to save himself with her or
else die with her.”

“Good!” cried Jules. “The nephew was worthy of his uncle. And then what
happened?”

“Then it was frightful. Cinders began to fall; darkness descended, so
intense that they could see nothing. There was general confusion,
outcry, and moaning. Wild with terror, the people fled at random,
knocking down and treading on those who were in their way. The greater
part were convinced that that night was the last, the eternal night that
was to swallow the world. Mothers went groping for their children, lost
in the crowd or perhaps crushed under the feet of the fugitives; they
called them with doleful cries to embrace them once more and then die.
Pliny and his old mother had seated themselves apart from the crowd.
From time to time they were obliged to get up and shake off the cinders
which would soon have buried them. At last the cloud dispersed and
daylight reappeared. The earth was unrecognizable; everything had
disappeared under a thick shroud of calcined dust.”

“And the houses, were they buried in the cinders?” asked Emile.

“At the foot of the mountain the dust thrown up by the volcano lay
deeper than the height of the tallest houses, and whole towns had
disappeared under the enormous bed of cinders. Amongst these were
Herculaneum and Pompeii. The volcano buried them alive.”

“With the inhabitants?” inquired Jules.

“With a small number, for most of them, like Pliny and his mother, had
time to flee to Messina. To-day, after being buried eighteen centuries,
Herculaneum and Pompeii are exhumed by the miner’s pick, just as they
were when caught by the cloud of volcanic cinders. Vineyards cover them
where they are not yet cleared.”

“These vineyards, then, are the roofs of houses!” said Emile.

“Higher than the roofs of houses. The traveler who visits the quarters
not yet uncovered, but made accessible by means of wells dug for the
purpose, descends under-ground to a great depth.”

                             CHAPTER XLVIII

                            THE BOILING POT

AS their uncle finished speaking, the postman came with a letter. A
friend advised Uncle Paul to go to town on pressing business, and he
wished to take advantage of the occasion to give his nephews the
diversion of a little journey. He had Jules and Emile dressed in their
Sunday clothes, and they set out to wait for the train at the
neighboring station. At the station Uncle Paul went up to a grating
behind which was a very busy man, and through a wicket he handed him
some money. In exchange the busy man gave him three pieces of cardboard.
Uncle Paul presented these pieces of cardboard to a man who guarded the
entrance to a room. The man looked and let them enter.

Here they are in what is called the waiting-room. Emile and Jules open
their eyes wide and say nothing. Soon they hear steam hissing. The train
arrives. At its head is the locomotive, which slackens its speed so as
to stop a moment. Through the window of the waiting-room Jules sees the
people passing. Something preoccupies him: he is trying to understand
how the heavy machine moves, what turns its wheels, which seem to be
pushed by an iron bar.

They enter the railway car, the steam hisses, the train starts, and they
are off. After a moment, when full speed had been gained: “Uncle Paul,”
said Emile, “see how the trees run, dance, and whirl around!” His uncle
made him a sign to be silent. He had two reasons for this: first, Emile
had just made a foolish remark, and, secondly, his uncle did not choose
to notice the giddy-pate’s self-betrayal in public.

Besides, Uncle Paul is not very communicative when traveling; he prefers
to maintain a discreet reserve and keep silence. There are people whom
you have never seen before, and perhaps will never see again, who
immediately become very familiar with their traveling companions. Rather
than hold their tongues they would talk to themselves. Uncle Paul does
not like such people; he considers them weak-minded.

By evening the three travelers had returned, all much pleased with their
trip. Uncle Paul had brought to a favorable conclusion his business in
town. Emile and Jules each came back with an idea. When they had done
honor to the excellent supper Mother Ambroisine had prepared on purpose
to wind up the holiday with a little treat, Jules was the first to
impart his idea to his uncle.

“Of all that I saw to-day,” he began, “what struck me most was the
engine at the head of the train, the locomotive that draws the long
string of cars. How do they make it move? I looked well, but could not
find out. It looks as if it went by itself, like a great beast on the
gallop.”

“It does not go by itself,” replied his uncle; “it is steam that puts it
in motion. Let us, then, first learn what steam is and what its power.

“When water is put on the fire, it first gets hot, then begins to boil,
sending off vapor, which is dissipated in the air. If the boiling
continues some time, it ends with there being nothing in the pot; all
the water has disappeared.”

“That is what happened to Mother Ambroisine day before yesterday,” put
in Emile. “She was boiling some potatoes, and having neglected to look
into the pot for some time, she found them without a drop of water, half
burnt. She had to begin all over again. Mother Ambroisine was not
pleased.”

“By heat,” continued Uncle Paul, “water becomes invisible, intangible,
as subtle as air. That is what is called vapor.”

“You told us that the moisture in the air, the cause of fogs and clouds,
is also vapor.” This from Claire.

“Yes, that is vapor, but vapor formed only by the heat of the sun. Now,
you must know that the stronger the heat, the more abundant is the
vapor. If you put a pot full of water on the fire, the burning heat of
the grate sets free incomparably more vapor than the temperature of a
hot summer sun could. As long as it escapes freely from the pot, the
vapor thus formed has nothing remarkable about it; so your attention has
never been arrested by the fumes of a boiling pot. But if the pot is
covered, covered tight, so as not to leave the slightest opening, then
the steam, which tends to expand to an enormous volume, is furious to
get out of its prison; it pushes and thrusts in all directions to remove
the obstacles that oppose its expansion. However solid it may be, the
pot ends by bursting under the indomitable pushing of the imprisoned
steam. That is what I am going to show you with a little bottle, and not
with a pot, which would not shut tight enough and the cover of which
could be easily pushed off by the steam. And besides, even if I had a
suitable pot, I should take care not to use it, for it might blow the
house up and kill us all.”

Uncle Paul took a glass vial, put a finger’s breadth of water into it,
corked it tightly with a cork stopper, and then tied the cork with a
piece of wire. The vial thus prepared was put on the ashes before the
fire. Then he took Emile, Jules, and Claire, and drew them quickly into
the garden, to see from a distance what would happen, without fear of
being injured by the explosion. They waited a few minutes, then _boom!_
They ran up and found the vial broken into a thousand pieces scattered
here and there with extreme violence.

“The cause of the explosion and the bursting of the bottle was the
steam, which, having no way of escape, accumulated and exerted against
its prison walls a stronger and stronger pressure as the temperature
rose. A time then came when the vial could no longer resist the pressure
of the steam, and it burst to pieces. They call elastic force the
pressure exerted by steam on the inside of pots that hold it prisoner.
The greater the heat, the stronger the pressure. With heat enough it may
acquire an irresistible power, capable of bursting, not only a glass
bottle, but also the thickest, most solid pots of iron, bronze, or any
other very resistant material. Is it necessary to say that under those
conditions the explosion is terrific? The fragments of the pot are
thrown with a violence comparable to that of a cannon-ball or a bursting
bomb. Everything standing in the way is broken or knocked down. Powder
does not produce more terrific results. What I have just shown you with
the glass vial is also not without some danger. You can be blinded with
this dangerous experiment, which it is well to see once under proper
precautions, but which it would be imprudent for you to repeat. I forbid
you all, understand, to heat water in a closed vial; it is a game that
might cost you your eyesight. If you should disobey me on this point,
good-by to stories; I would not keep you with me any longer.”

“Don’t be afraid, Uncle,” Jules hastened to interpose; “we will be
careful not to repeat the experiment; it is too dangerous.”

“Now you know what makes the locomotive and a great many other machines
move. In a strong boiler, tightly closed, steam is formed by the action
of a hot furnace. This steam, of an enormous power, makes every effort
to escape. It presses particularly on a piece placed for that purpose,
which it chases before it. From that a movement results that sets
everything going, as you will see in the case of the locomotive. To
conclude, let us remember that in every steam engine the essential
thing, the generator of the force, is a boiler, a closed pot that
boils.”

                              CHAPTER XLIX

                             THE LOCOMOTIVE

UNCLE PAUL showed his nephews the following picture, and explained it to
them.

[Illustration: An old-time Locomotive]

“This picture represents a locomotive. The boiler where the steam is
generated, the boiling pot, in short, forms the greater part of it. It
is the large cylinder that goes from one end to the other, borne on six
wheels. It is built of solid iron plates, perfectly joined together with
large rivets. In front the boiler terminates in a smoke-stack; behind,
in a furnace, the door of which is represented as open. A man, called a
stoker, is constantly occupied in filling the furnace with pit-coal,
which he throws in by the shovelful; for he must keep up a very hot fire
to heat the volume of water contained in the boiler and obtain steam in
sufficient quantity. With an iron bar he pokes the fire, arranges it,
makes it burn fast. That is not all: skilful arrangements are made to
utilize the heat and warm the water quickly. From the end of the furnace
start numerous copper pipes which traverse the water from one end to the
other of the boiler, and terminate at the smoke-stack. You will see some
in B where the picture supposes a part of the casing taken away to show
the interior. The flame of the furnace runs through these pipes,
themselves surrounded by water. By this means the fire is made to
circulate through the very midst of the water, and so steam is obtained
very quickly.

[Illustration: A modern Locomotive]

“Now look at the front of the locomotive. In A is seen a short cylinder
closed tightly, but represented in the picture with a part of the
outside removed to show what is within. There are two of these
cylinders, one on the right, the other on the left of the locomotive.
Inside the cylinder is an iron stopper called a piston. The steam from
the boiler enters the cylinder alternately in front of and behind the
piston. When the steam comes in front, what is behind escapes freely
into the air by an orifice that opens of itself at the right moment.
This escaping steam ceases to press on the piston, since it finds its
prison open and that it can get out. We do not try to force doors when
other outlets are open. So does steam act: the instant it can escape
freely, it ceases to push. The entering steam, on the contrary, finds
itself imprisoned. It pushes the piston, therefore, with all its
strength and drives it to the other end of the cylinder. But then the
rôles immediately change. The steam that hitherto has been pushing,
escapes into the air and ceases to act, while on the other side a jet of
steam rushes in from the boiler and begins to push in the contrary
direction.”

“Let me repeat it,” said Jules, “to see if I have understood it
properly. Steam comes from the boiler, where it forms unceasingly. It
goes into the cylinder before and behind the piston by turns. When it
gets in front, that behind escapes into the air and no longer pushes;
when it gets behind, that in front escapes. The piston, pushed first one
way, then the other, alternately, must advance and retreat, go and come,
in the cylinder. And then?”

“The piston is in the form of a solid iron rod that enters the cylinder
through a hole pierced in the middle of one of the ends, and just large
enough to give free passage to the rod, without letting the steam
escape. This rod is bound to another iron piece called a crank, and
finally the crank is attached to the neighboring wheel. In the picture
all these things can easily be seen. The piston, advancing and
retreating in turn in the cylinder, pushes the crank forward and back,
and the crank thus makes the great wheel turn. On the other side of the
locomotive the same things are taking place by means of a second
cylinder. Then the two great wheels turn at the same time and the
locomotive moves forward.”

“It isn’t so hard as I thought,” Jules remarked. “Steam pushes the
piston, the piston pushes the crank, the crank pushes the wheel, and the
engine moves.”

“After acting on the piston, the steam enters the same chimney that the
smoke comes out of. So you can see this smoke-stack sometimes throwing
out white puffs, sometimes black. These latter are smoke coming from the
furnace through the tubes that go through the water; the others come
from the steam thrown out of the cylinders after each stroke of the
piston. These white puffs, in rushing violently from the cylinder to the
smoke-stack after acting on the piston, make the noise of the engine as
it moves.”

“I know: _pouf! pouf! pouf!_” exclaimed Emile.

“The locomotive carries with it a supply of coal to feed the fire, and a
supply of water to renew the contents of the boiler as fast as
evaporation may require. These supplies are carried in the tender; that
is to say, in the vehicle that comes immediately behind the locomotive.
On the tender are the stoker, who tends the furnace, and the engineer,
who controls the passage of the steam into the cylinders.”

“The man in the picture is the engineer?” Emile asked.

“He is the engineer. He holds his hand on the throttle, which allows the
steam from the boiler to enter the cylinders in greater or less
quantity, according to the speed he wishes to obtain. By one movement of
the throttle, the steam is cut off from the cylinders and the engine
stops; by another movement the steam is admitted and the locomotive
moves, slowly or rapidly at will.

“The power of a locomotive is no doubt considerable; however, if it is
able to draw with great speed a long train of cars, all heavily loaded,
this is due, above all, to the preparation of the road on which it runs.
Strong bars of iron, called rails, are fixed solidly on the road, all
along its length, in two parallel lines, on which all the wheels of the
train roll without ever running off. A light flange with which the
wheels are furnished keeps the train from slipping off the rails.

“The iron road not having the inconveniences of other roads, that is to
say the ruts, pebbles, and inequalities that impede the progress of
carriages and cause the waste of much energy, the whole traction of the
locomotive is utilized, and the results obtained are wonderful. A
passenger engine draws at a rate of twelve leagues an hour a train
weighing as much as 150,000 kilograms. A freight engine pulls at about
seven leagues an hour a total weight of 650,000 kilograms. More than
1300 horses would be necessary to replace the first locomotive, and more
than 2000 to replace the second, if they were employed to transport
similar loads with the same velocity and to the same distances by the
aid of cars running on rails. What an army of horses it would require
with wagons running on ordinary roads having all the inequalities that
cause such a great loss of energy!

“And now, my little friends, think of the thousands of locomotives
running daily in all parts of the world, annihilating distances, as it
were, and bringing the most distant nations together; think what a vast
number of machines of all kinds, moved by steam, are ceaselessly working
for man; think how the engine that makes a warship move, sometimes
represents in itself the united strength of 42,000 horses; think of all
these things, and see what inconceivable development of power man’s
genius has given to him with a few shovelfuls of coal burning under a
pot of water!”

“Who first thought of the use of steam?” asked Jules. “I should like to
remember his name.”

“The use of steam as a mechanical power was proposed nearly two hundred
years ago by one of the glories of France, the unfortunate Denis Papin,
who, after giving the first suggestion of the steam-engine, source of
incalculable riches, languished in a foreign land, poverty-stricken and
forlorn. To realize his fruitful idea, which was to increase man’s
motive power a hundredfold, he could hardly find a paltry half-crown.”

                               CHAPTER L

                          EMILE’S OBSERVATION

EMILE’S turn came to tell what he had seen.

“When you made me a sign to be silent,” said he, “it seemed to me as if
the trees were walking. Those along the railroad were going very fast;
farther away, the big poplars, ranged in long rows, were going with
their heads waving as if saying good-by to us. Fields turned around,
houses fled. But on looking closer I soon saw that we were moving and
all the rest was motionless. How strange! You see something running that
is really not moving at all.”

“When we are comfortably seated in the railway car,” his uncle replied,
“without any effort on our part to go forward, how can we judge of our
motion except by the position we occupy in relation to the objects that
surround us? We are aware of the way we are going by the continual
changing of the objects in sight, and not by any feeling of fatigue,
since we do not move our legs. But the objects and people nearest to us
and always before our eyes, our traveling companions and the furnishings
of the car, remain for us in the same position. The left-hand neighbor
is always at the left, the one in front is always in front. This
apparent immobility of everything in the car makes us lose consciousness
of our own movement; then we think ourselves immobile and fancy we see
flying in an opposite direction exterior objects, which are always
changing as we look at them. Let the train stop, and immediately trees
and houses cease moving, because we no longer have a shifting point of
view. A simple carriage drawn by horses, a boat borne along by the
current, lend themselves to this same curious illusion. Every time we
ourselves are gently moved along, we tend, more or less, to lose
consciousness of this movement, and surrounding objects, in reality
immobile, seem to us to move in a contrary direction.”

“Without being able to explain it to myself well,” returned Emile, “I
see that it is so. We move and we think we see the other things moving.
The faster we go, the faster the other things seem to go.”

“You hardly suspect, my little friends, that Emile’s naïve observation
leads us straight to one of the truths that science has had the most
trouble in getting accepted, not on account of its difficulty, but
because of an illusion that has always deceived most people.

“If men passed their whole life on a railroad, without ever getting out
of the car, stopping, or changing speed, they would firmly believe trees
and houses to be in motion. Except by profound reflection, of which not
everybody is capable, how could it be otherwise, since none would have
seen the testimony of their eyes contradicted by experience? Of those
that have been convinced, one sharper than the others rises and says
this: ‘You imagine that the mountains and houses move while you remain
at rest. Well, it is just the opposite: we move and the mountains,
houses, and trees stand still.’ Do you think many would agree with him?
Why! they would laugh at him, for each one sees, with his own eyes,
mountains running, houses traveling. I tell you, my children, they would
laugh at him.”

“But, Uncle—” began Claire.

“There is no _but_. It has been done. They have done worse than laugh;
they have become red with anger. You would have been the first to laugh,
my girl.”

“I should laugh at somebody asserting that the car moves and not the
houses and mountains?”

“Yes, for an error that accompanies us all through life and that every
one shares, is not so easily removed from the mind.”

“It is impossible!”

“It is so possible that you yourself, at every turn, make the mountain
move and the car that carries us stand still.”

“I do not understand.”

“You make the round earth, the car that bears us through celestial
space, stand still; and you give motion to the sun, the giant star that
makes our earth seem as nothing by comparison. At least, you say the sun
rises, pursues its course, sets, and begins its course again the next
day. The enormous star moves, the humble earth tranquilly watches its
motion.”

“The sun does certainly seem to us,” said Jules, “to rise at one side of
the sky and set at the other, to give us light by day. The moon does the
same, and the stars too, to give us light at night.”

“Listen then to this. I have read, I don’t know where, of an eccentric
person whose wrong-headedness could not reconcile him to simple methods.
To attain the simplest result he would use means whose extravagance
caused every one to laugh. One day, wishing to roast a lark, what do you
think he took it into his head to do? I will give you ten, a hundred
guesses. But, bah! you would never guess it. Just imagine! He
constructed a complicated machine, with much wheelwork and many cords,
pulleys, and counterpoises; and when it was started there was a variety
of movement, back and forth, up and down. The noise of the springs and
the grinding of the wheels biting on each other was enough to make one
deaf. The house trembled with the fall of the counterpoises.”

“But what was the machine for?” asked Claire. “Was it to turn the lark
in front of the fire?”

“No, indeed; that would have been too simple. It was to turn the fire
before the lark. The lighted firebrands, the hearth and chimney, dragged
heavily by the enormous machine, all turned around the lark.”

“Well, that beats all!” Jules ejaculated.

“You laugh, children, at this odd idea; and yet, like that eccentric
man, you make the firebrands, hearth, the whole house turn around a
little bird on the spit. The earth is the little bird; the house is the
heavens, with their enormous, innumerable stars.”

“The sun isn’t very big—at most, as large as a grindstone,” said Jules.
“The stars are only sparks. But the earth is so large and heavy!”

“What did you just say? the sun as large as a grindstone? the stars only
little sparks? Ah, if you only knew! Let us begin with the earth.”

                               CHAPTER LI

                   A JOURNEY TO THE END OF THE WORLD

“A SMALL boy, of Jules’s age and, like him, desirous to learn, one
morning was making his preparations for a journey. Never had a navigator
getting ready for a voyage over distant seas shown more zeal.
Provisions, the first necessity in long expeditions, were not forgotten.
Breakfast was doubled. There were in the basket six nuts, a
bread-and-butter sandwich, and two apples! Where can one not go with all
that? The family was not informed: they might have dissuaded the
audacious traveler from his project by acquainting him with the perils
of the expedition. For fear of softening before his mother’s tears, he
kept silent. Basket in hand, without saying good-by to any one, he takes
his departure. Soon he is in the country. To left or right makes no
difference to him; all roads lead whither he wishes to go.”

“Where does he want to go?” asked Emile.

“To the end of the world. He takes the right-hand road, which is
bordered by a hawthorn hedge where golden green beetles rustle and
shine. But the beautiful insects do not stop him for a moment, nor yet
the little red-bellied fish that play in the streamlet. The day is so
short and the journey so long! He keeps on walking straight ahead,
sometimes shortening the distance by cutting across fields. At the end
of an hour the sandwich, chief item in the provisions, had been eaten,
although the eating of it was regulated by the wise economy of a prudent
traveler. Quarter of an hour later an apple and three nuts were gone.
Appetite comes quickly to those who tire themselves. It comes so quickly
that at a turn of the road, in the shade of a large willow, the second
apple and the three remaining nuts are taken out of the basket. The
provisions were exhausted, and (no less grave a matter) legs refused to
go. Just imagine the situation. The journey had lasted two hours, and
the end proposed was no nearer, not a bit. The little boy retraced his
steps, persuaded that with better legs and more provisions he would
succeed another time in his project.”

“What was this project?” Jules asked.

“I told you: the audacious child wished to reach the end of the world.
According to his ideas, the sky was a blue vault, which kept getting
lower until it rested on the edge of the earth, so that, if ever he
arrived there, he would have to walk bent over so as not to bump his
head against the firmament. He started with the idea that he should soon
be able to touch the sky with his hand; but the blue vault, retiring as
he advanced, was always at the same distance. Fatigue and want of
provisions made him renounce further continuance of his journey.”

“If I had known that little boy,” said Emile, “I would have dissuaded
him from his expedition. It is impossible, however far one goes, to
touch the sky with the hand, even with the help of the tallest ladder.”

“If I remember aright, Emile has not always been of that opinion,” said
his uncle.

“That is true, Uncle. Like the little boy you have been telling about, I
believed that the sky was a large blue cover resting on the earth. By
good walking one ought to reach the edge of the cover and the end of the
world. I thought, too, that the sun rose behind these mountains, and set
behind those on the opposite side, where there was a deep well that the
sun plunged into and remained hidden during the night. One day you took
me to the mountains where the edges of the blue cover seem to rest. It
was a long way off, I remember; you lent me your cane, which helped me
in walking. I did not see any well for the sun to plunge into;
everything looked just as it does here. The edge of the sky still seemed
to rest on the earth, only much farther away. And you told me that by
going to the end of what we saw, then farther and farther still, we
should find the same appearance everywhere, without ever seeing the end
of a vault that does not really exist.”

“Nowhere, as all three of you know, does the sky rest on the earth;
nowhere is there any danger of striking one’s head against the
firmament; everywhere the blue vault has the same appearance as here.
You know, too, that in always going ahead you meet with plains,
mountains, valleys, water-courses, seas; but nowhere are there any
barriers marking the limits of the world.

“Imagine a large ball suspended in the air by a thread, and on this ball
a gnat. If this gnat should take a notion to go all over the surface, is
it not true that it could come and go over the ball, above, below, on
the side, without ever encountering an obstacle, without ever seeing a
barrier rise up to block its passage? Is it not equally true that if it
always kept on in the same direction, the gnat would end by making the
tour of the ball and would come back to its starting-point? So it is
with us on the surface of the earth, though we are far more
insignificant when compared with the globe that bears us than is the
tiniest gnat in comparison with the biggest ball you can imagine.
Without ever encountering a barrier, without ever touching the cupola of
the sky, we come and go in a thousand different directions, we
accomplish the most distant journeys, even make the tour of the earth
and return to our starting-point. The earth, then, is round; it is an
immense ball that swims without support in celestial space. As to the
blue vault that arches above us, it is mere appearance caused by the
blue color of the air enveloping the earth on all sides.”

“The ball on which your imaginary gnat travels is suspended by a thread.
By what chain is the enormous ball of the earth hung?” asked Jules.

“The earth is not suspended from the firmament by any celestial chain,
nor does it rest upon any support, like a geographical globe on its
pedestal. According to an Indian legend the terrestrial globe is borne
upon four bronze columns.”

“And what do the four columns rest on, in their turn?”

“They rest on four white elephants.”

“And the white elephants?”

“They rest on four monstrous turtles.”

“And the turtles?”

“Well, they swim in an ocean of milk.”

“And the ocean of milk?”

“The legend says nothing about that, and it is right to be silent. It
would have been better not to imagine all these various supports,
resting one on another, to hold the earth up. Suppose a pedestal for the
earth, then a second to uphold the first, then a third, fourth,
thousandth, if you like; it is only postponing the question without
answering it, since finally, after having erected all the supports
imaginable, one must ask what will the last one rest on. Perhaps you are
thinking of the vault of the heavens, which might well sustain the
earth; but know that this vault has no reality, that it is nothing but
an appearance caused by the air. Besides, thousands of travelers have
gone over the earth in every direction, and nowhere have they seen
either a suspending chain or a pedestal of any kind. Everywhere they see
only what is to be seen here. The earth is isolated in space; it swims
in a void without any support, just as do the moon and the sun.”

“But, then, why doesn’t it fall?” persisted Jules.

“To fall, my little friend, is to rush earthward as a stone does when
raised in the hand and then left to itself. How can the large ball rush
to the earth, when it is the whole earth? Is it possible for a thing to
rush toward itself?”

“No.”

“Well, then! Besides, imagine this. All is the same around the
terrestrial globe; properly speaking, there is no up or down, no right
or left. We call _up_ the direction toward adjacent space, or toward the
sky; but remember that there is sky also on the other side of the earth,
that there it is just the same as we see it here, and that this is true
for all parts of the earth’s surface. If it seemed to you quite simple
that the earth does not rush toward the sky which is above us, why
should you expect it to rush toward the opposite sky? To fall toward the
opposite sky would be to rise, as the lark rises here, when with one
stroke of the wing it takes its flight and soars above us.”

                              CHAPTER LII

                               THE EARTH

“THE earth is round, as proved by the following facts. When, in order to
reach the town he is journeying toward, a traveler crosses a level plain
where nothing intercepts his view, from a certain distance the highest
points of the town, the summits of towers and steeples, are seen first.
From a lesser distance the spires of the steeples become entirely
visible, then the roofs of buildings themselves; so that the view
embraces a great number of objects, beginning with the highest and
ending with the lowest, as the distance diminishes. The curvature of the
ground is the cause of it.”

[Illustration: The Earth]

Uncle Paul took a pencil and traced on paper the picture that you see
here; then he continued:

“To an observer at A the tower is quite invisible because the curvature
of the ground hides the view. To the observer at B the upper half of the
tower is visible, but the lower half is still hidden. Finally, when the
observer is at C he can see the whole tower. It would not be thus if the
earth were flat. From any distance the whole of a tower would be
visible. Afar off, no doubt, it would be seen with less clearness than
near to, on account of the distance; but it could be seen more or less
well from top to bottom.”

Here is another drawing of Uncle Paul’s, representing two spectators, A
and B, who, placed at very different distances, nevertheless see the
tower from top to bottom on a flat surface. He resumed his talk.

[Illustration: A Tower]

“On dry land it is rare to find a surface that in extent and regularity
is adapted to the observation I have just told you about. Nearly always
hills, ridges, or screens of verdure intercept the view and prevent
one’s seeing the gradual appearance, from summit to base, of the tower
or steeple that one is approaching. On the sea no obstacle bars the view
unless it be the convexity of the waters, which follow the general
curvature of the earth. It is, accordingly, there especially that it is
easy to study the phenomena produced by the rounded form of the earth.

“When a ship coming from the open sea approaches the coast, the first
points of the shore visible to those on board are the highest points,
like the crests of mountains. Later the tops of high towers come into
sight; still later the edge of the shore itself. In the same way an
observer who witnesses from the shore the arrival of a vessel begins by
perceiving the tops of the masts, then the topsails, then the sails next
below, and finally the hull of the vessel. If the vessel were departing
from the shore, the observer would see it gradually disappear and
apparently plunge under the water, all in inverse order; that is to say,
the hull would be first hidden from view, then the low sails, then the
high ones, and finally the top of the mainmast, which would be the last
to disappear. Four strokes of the pencil will make you understand it.”

                     [Illustration: A Ship at Sea]

“How large is the earth?” was the next question from Jules.

“The earth is forty million meters in circumference or 10,000 leagues,
for a league measures four kilometers. To encircle a round table, you
take hold of hands, three, four, or five of us. To encircle in the same
manner the vast bosom of the earth, it would take a chain of people
about equal to the whole population of France. A traveler able to walk
day after day at the rate of ten leagues a day, which no one could do,
would take three years to girdle the globe, supposing it to be all land
and no sea. But, where are the hamstrings that could resist three years
of such continual fatigue, when a walk of ten leagues generally exhausts
our strength and makes it impossible for us to begin again the next
morning?”

“The longest walk I ever took was to the pine woods, where we went to
look for the nest of the processionary caterpillars, the day of the
thunderstorm. How many leagues did we go?”

“About four, two to go and two to come back.”

“Only four leagues! All the same I was played out. At the end I could
hardly put one foot before the other. It would take me, then, from seven
to eight years to go round the world, walking every day as far as my
strength would let me.”

“Your calculation is right.”

“The earth then is a very large ball?”

“Yes, my friend, very large. Another example will help you to understand
it. Let us represent the terrestrial globe by a ball of greater diameter
than a man’s height—by a ball two meters in diameter; then, in correct
proportion, represent in relief on its surface some of the principal
mountains. The highest mountain in the world is Gaurisankar, a part of
the Himalaya chain, in central Asia. Its peaks rise to a height of 8840
meters. Rarely are the clouds high enough to crown its crest, and its
base covers the extent of an empire. Alas! what does man become,
materially, in face of such a prodigious colossus! Well, let us raise
the giant on our large ball representing the earth; do you know what
will be needed to represent it? A tiny little grain of sand which would
be lost between your fingers, a grain of sand that would stand out in
relief only a millimeter and a third! The gigantic mountain that
overwhelmed us with its immensity is nothing when compared with the
earth. The highest mountain in Europe, Mont Blanc, whose height is 4810
meters, would be represented by a grain of sand half as large as the
other.”

“When you told us of the roundness of the earth,” put in Claire, “I
thought of the enormous mountains and deep valleys, and asked myself
how, with all these great irregularities, the earth could nevertheless
be round. I see now that these irregularities are a mere nothing in
comparison with the immensity of the terrestrial ball.”

“An orange is round in spite of the wrinkles in its skin. It is the same
with the earth: it is round in spite of the irregularities of its
surface; it is an enormous ball sprinkled with grains of dust and sand
proportioned to its size, and these are mountains.”

“What a big ball!” exclaimed Emile.

“To measure the circumference of the earth is not an easy thing, you may
be sure; and yet they have done more than that: they have weighed the
immense ball as if it were possible to put it in a scale-pan with
kilograms for counterweights. Science, my dear children, has resources
demonstrating in all its grandeur the power of the human mind. The
immense ball has been weighed. How it was done cannot be explained to
you to-day. No scales were used, but it was accomplished by the power of
thought with which God has endowed us, to solve, to His glory, the
sublime enigma of the universe; by the force of reason, for which the
burden of the earth is not too heavy. This burden is expressed by the
figure 6 followed by twenty-one zeros, or by 6 sextillions of
kilograms.”

“That number means nothing to me; it is too large,” Jules declared.

“That is the trouble with all large numbers. Let us get around the
difficulty. Suppose the earth placed on a car and drawn on a surface
like that of our roads. For such a load, what should the team be? Let us
put in front a million horses; and in front of that row a second
million; then a third row, still of a million; a hundredth, finally a
thousandth. We shall thus have a team of a thousand millions of horses,
more than could be fed in all the pastures of the world. And now start;
apply the whip. Nothing would move, my children; the power would be
insufficient. To start the colossal mass, it would need the united
efforts of a hundred millions of such teams!”

“I don’t grasp it any better,” said Jules.

“Nor I, it is so enormous,” assented his uncle.

“Yes, enormous, Uncle.”

“So that the mind gets lost in it,” said Claire.

“That is what I wanted to make you acknowledge,” concluded Uncle Paul.

                              CHAPTER LIII

                             THE ATMOSPHERE

“IF you pass your hand quickly before your face, you feel a breath blow
on your cheeks. This breath is air. In repose it makes no impression on
us; put in motion by the hand, it reveals its presence by a light shock
that produces an impression of freshness. But the shock from the air is
not always, like this, a simple caress. It can become very brutal. A
violent wind, which sometimes uproots trees and overthrows buildings, is
still air in motion, air that flows from one country to another like a
stream of water. Air is invisible, because it is transparent and almost
colorless. But if it forms a very thick layer through which one can
look, its feeble coloring becomes perceptible. Seen in small quantities,
water appears equally colorless; seen in a deep layer, as in the sea, in
a lake, or in a river, it is blue or green. It is the same with air: in
thin strata it seems deprived of color; in a layer several leagues in
thickness, it is blue. A distant landscape appears to us bluish, because
the thick bed of intervening air imparts to it its own color.

“Now air forms all around the earth an envelope fifteen leagues thick.
It is the aërial sea or atmosphere, in which the clouds swim. Its soft
blue tint causes the sky’s color. It is in fact the atmosphere that
produces the appearance of a celestial vault.

“Do you know, my children, what is the use of this aërial sea at the
bottom of which we live as fish live in water?”

“Not very well,” Jules replied.

“Without this ocean of air life would be impossible, plant life as well
as animal. Listen. Chief of those imperious needs to which we are
subjected are those of eating, drinking, and sleeping. As long as hunger
is only its diminutive, appetite, that savory seasoning of the grossest
viands; as long as thirst is only that nascent dryness of the mouth that
gives so great a charm to a glass of cold water; as long as sleepiness
is nothing more than that gentle lassitude that makes us desire the
night’s rest, so long is it the attraction of pleasure rather than the
rude prick of pain that urges the satisfaction of these primordial
needs. But if their satisfaction is too long delayed, they impose
themselves as inexorable masters and command by torture. Who can think
without terror of the agonies of hunger and thirst! Hunger! Ah! you do
not know what it is, my children, and God preserve you from ever knowing
it! Hunger! If you could have any idea of its tortures, your heart would
be oppressed at the thought of the unhappy ones who experience it. Ah!
my dear children, always help those that are hungry; help them, and
give, give; you will never do a nobler deed in this world. Giving to the
poor is lending to the Lord.”

Claire had put her hand before her eyes to hide a tear of emotion. She
had observed a flash on her uncle’s face that spoke from the depth of
his heart. After a moment’s pause Uncle Paul continued:

“There is, however, a need before which hunger and thirst, however
violent they may be, are mute; a need always springing up afresh and
never satisfied, which continually makes itself felt, awake or asleep,
night or day, every hour, every moment. It is the need of air. Air is so
necessary to life that it has not been given us to regulate its use, as
we do with eating and drinking, so as to guard us from the fatal
consequences that the slightest forgetfulness would cause. It is, as it
were, without consciousness or volition on our part that the air enters
our body to perform its wonderful part. We live on air more than
anything else; ordinary nourishment comes second. The need of food is
only felt at rather long intervals; the need of air is felt without
ceasing, always imperious, always inexorable.”

“And yet, Uncle,” said Jules, “I have never thought of feeding myself
with air. It is the first time I ever heard that air is so necessary for
us.”

“You have not given it a thought, because all that is done for you; but
try a moment to prevent air entering into your body: close the ways to
it, the nose and mouth, and you will see!”

Jules did as his uncle told him, shut his mouth and pinched his nose
with his fingers. At the end of a moment, his face red and puffed up,
the little boy was obliged to put an end to his experiment.

“It is impossible to keep it up, Uncle; it suffocates a person and makes
him feel as if he should certainly die if it kept on a little longer.”

“Well, I hope you are convinced of the necessity of air in order to
live. All animals, from the tiniest mite, hardly visible, to the giants
of creation, are in the same condition as you: on air, first of all,
their life depends. Even those that live in the water, fish and others,
are no exception to this rule. They can live only in water into which
air infiltrates and dissolves. When you are older you shall see a
striking experiment which proves how indispensable to life is the
presence of air. You put a bird under a glass dome, shut tight
everywhere; then with a kind of pump the air is drawn out. As it is
withdrawn from the inside of the glass cage, the bird staggers,
struggles a moment in an anguish horrible to see, and falls dead.”

“It must take a lot of air,” was Emile’s comment, “to supply the needs
of all the people and animals in the world. There are so many!”

“Yes, indeed; a great quantity is needed. One man needs nearly 6000
liters of air an hour. But the atmosphere is so vast that there is
plenty of air for all. I will try to make you understand it.

“Air is one of the most subtle of substances; a liter of it weighs only
one gram and three decigrams. That is very little: the same volume of
water weighs 1000 grams; that is to say, 769 times as much. However,
such is the enormous extent of the atmosphere that the weight of all the
air composing it outstrips your utmost powers of imagination. If it were
possible to put all the air of the atmosphere into one of the pans of an
immense pair of scales, what weight do you think it would be necessary
to put into the other pan to make it equal the air? Don’t be afraid of
exaggerating; you can pile up thousands on thousands of kilograms; if
air is very light, the aërial sea is very vast.”

“Let us put on a few millions of kilograms,” suggested Claire.

“That is a mere trifle,” her uncle replied.

“Let us multiply it by ten, by a hundred.”

“It is not enough, the pan would not be raised. But let me tell you the
answer, for in this calculation numerical terms would fail you. For the
great weight I am supposing, the heaviest counterweights would be
insignificant. New ones must be invented. Imagine, then, a copper cube,
a kilometer in each dimension; this metallic die, measuring a quarter of
a league on its edge, shall be our unit of weight. It represents nine
thousand millions of kilograms. Well, to balance the weight of the
atmosphere, it would be necessary to put into the other pan 585,000 of
these cubes!”

“Is it possible!” Claire exclaimed.

“I told you so! Imagination vainly seeks to picture the stupendous mass
of the layer of air wound like a scarf by the Creator around the earth.
Now do you know what relation it bears to the terrestrial globe—this
ocean of air having a weight represented by half a million of copper
cubes a quarter of a league each way? Scarcely what the imperceptible
velvety down of a peach is to the peach itself. What, then, are we,
materially, we poor beings of a day, who move about at the bottom of
this atmospheric sea! But how great we are through thought, which makes
game of weighing the atmosphere and the earth itself! In vain does the
material universe overwhelm us with its immensity; the mind is superior
to it, because it alone knows itself, and it alone, by a sublime
privilege, has knowledge of its divine author.”

                              CHAPTER LIV

                                THE SUN

EARLY in the morning Uncle Paul and his nephews climbed the neighboring
hill to see the sunrise. It was still quite dark. The only persons they
met in passing through the village were the milkmaid, on her way to town
with her butter and milk, and the blacksmith hammering away at the
red-hot iron on his anvil, while the glow from the forge illumined the
darkness of the road.

[Illustration: The Sun]

Sheltered by a clump of juniper-trees, Paul and the three children await
the grand spectacle they have come to the top of the hill to see. In the
east the sky is getting lighter, the stars turn pale and go out one by
one. Flakes of rosy cloud swim in a brilliant streak of light whence
gradually there rises a soft illumination. It reaches the zenith, and
the blue of day reappears with all its delicate transparency. This cool
morning light, this half-daylight that precedes the rising of the sun,
is the aurora or morning twilight. In the meantime a lark, the joy of
the fields, takes wing to the highest clouds, like a rocket, and is the
first to salute the awakening day. It mounts and mounts, always singing,
as if to get in front of the sun; and with its enthusiastic songs it
celebrates in the high heavens the glory of the day-bringer. Listen:
there is a breath of wind in the foliage, which stirs and rustles; the
little birds are waking up and chirping; the ox, already led to work in
the fields, stops as if thinking, raises its large eyes full of
gentleness, and lows; everything becomes animated, and, in its own
language, renders thanks to the Master of all things, who with His
powerful hand brings us back the sun.

And here it is: a bright thread of light bursts forth, and the tops of
the mountains are suddenly illumined. It is the edge of the sun
beginning to rise. The earth trembles before the radiant apparition. The
shining disc keeps rising: there it is almost whole, now completely so,
like a grindstone of red-hot iron. The mist of the morning moderates its
glare and allows one to look it in the face; but soon no one could
endure its dazzling splendor. In the meantime its rays inundate the
plain; a gentle heat succeeds the keen freshness of the night; the mists
rise from the depths of the valleys and are dissipated; the dew,
gathered on the leaves, becomes warm and evaporates; on all sides there
is a resumption of life, of the animation suspended during the night.
And all day, pursuing its course from east to west, the sun moves on,
flooding the earth with light and heat, ripening the yellow harvest,
giving perfume to the flowers, taste to fruit, life to every creature.

Then Uncle Paul, in the shade of the juniper-trees, began his talk.

“What is the sun? Is it large, is it very far away? That, my children,
is what I should now like to teach you.

“To measure the distance from one point to another, you know of only one
means: that of laying off, as many times as it will go, the unit of
length, the meter, from one end to the other of the distance to be
measured. But science has methods adapted to the measuring of distances
that one cannot travel in person; it tells us what must be done to find
the height of a tower or mountain, without going to the top, without
even approaching the base. They are methods of the same kind as are
employed to calculate the distance that separates us from the sun. The
result of the astronomer’s calculations is that we are distant from the
sun 38 millions of leagues of 4000 meters each. This distance is
equivalent to 3800 times the circumference of the earth. I told you
that, to make the tour of the terrestrial globe, a man, a good walker,
capable of walking ten leagues a day, would take about three years. He
would need, then, nearly twelve thousand years to go from the earth to
the sun, supposing that the journey were possible. The longest human
life is incomparably too short for a journey of this length ever to be
accomplished by one person; and a hundred generations of a hundred years
each, succeeding one another on the journey and uniting their efforts,
would not even be enough.”

“And a locomotive,” asked Jules, “how long would it take to get over
that distance?”

“Do you remember how fast it goes?”

“I saw it myself the day we took the trip with you. If one looks out,
the road seems to fly back so fast it frightens you and makes you
dizzy.”

“The locomotive that drew us went at the rate of about ten leagues an
hour. Let us suppose a locomotive that never stops and that goes still
faster, or fifteen leagues an hour. Rushing at that speed, the engine
would go from one end of France to the other in less than a day; and
yet, to cover the distance from the earth to the sun, it would take more
than three centuries. For such a journey, the fastest engine ever made
by the hand of man is hardly more than a sluggish snail ambitious to
make the tour of the world.”

“And I who thought, not long ago,” said Emile, “that by climbing to the
roof and with the aid of a long reed I could touch the sun!”

“To one who trusts to appearances the sun is only a dazzling disc, at
the most as large as a grindstone.”

“That is what I said yesterday,” observed Jules. “But, as it is so far
away, it might well be as large as a millstone.”

“In the first place, the sun is not flat like a grindstone; it has, like
the earth, the shape of a ball. Furthermore, it is much larger than a
grindstone, or even than a millstone.

“Objects seem to us small in proportion to their distance from us, until
finally they become invisible. A high mountain seen from afar seems only
a moderate-sized hill; the cross that surmounts a steeple, seen from
below, looks very small despite its very large dimensions. It is the
same with the sun: it looks so small only because it is very far off;
and as the distance is prodigious, its size must be excessive; if not,
instead of looking to us like a dazzling grindstone, it would cease to
be visible to us.

“You found the terrestrial globe enormous; and, despite my comparisons,
your imagination, I am sure, has not been able to picture things
properly. How will it be with the sun, which is one million four hundred
thousand times as large as the earth! If we suppose the sun hollow like
a spherical box, to fill it would take one million four hundred thousand
balls the size of the earth.

“Let us try another comparison. To fill the measure of capacity called
the liter, it takes about 10,000 grains of wheat. It would take, then,
100,000 to fill 10 liters or one decaliter, and 1,400,000 to fill 14
decaliters. Well, suppose in one pile 14 decaliters of wheat, and beside
it one solitary grain of wheat. For the respective sizes, this isolated
grain represents the earth; the pile of 14 decaliters represents the
sun.”

“How wrong we were!” Claire exclaimed. “This little shining disc, to
which, for fear of exaggeration, we should have hesitated to assign the
dimensions of a millwheel, is a globe so big that in comparison with its
gigantic size the earth is as nothing.”

“Oh, God in heaven!” cried Jules.

“Yes, my friend, you may well say, ‘God in heaven,’ for the mind is
bewildered at the thought of this inconceivable mass. Say: God in
heaven! how great You are, You who out of nothing have created the sun
and the earth, and hold them both in the shadow of Your hand!

“I have not finished, my dear children. One day, in speaking to you of
lightning and thunder, I told you that light moves with excessive
rapidity. In fact, to come to us from the sun, to cover the distance
that a locomotive at its highest speed would take three hundred years to
cover, a ray of light needs only the half of a quarter of an hour, or
about eight minutes. Now listen to this. Astronomy teaches us that each
star, small as it may appear from here, is itself a sun comparable in
size to ours; it tells us that these suns, of which we with the naked
eye can perceive only a very small part, are so numerous that it is
impossible to count them; it tells us that their distance is so great
that, to come to us from the nearest star, light, which travels so fast,
as I have just told you, takes nearly four years; to reach us from
others that are by no means the most distant it takes whole centuries.
After that, if you can, estimate the distance that separates us from
those far-off suns; think also of their number and size. But no, do not
try: the intellect is overwhelmed by these immensities in which is
revealed all the majesty of God’s handiwork. Do not try, it would be in
vain; but let arise from your heart the burst of admiration that you
cannot suppress, and bless God, whose infinite power has scattered suns
through the boundless regions of celestial space.”

                               CHAPTER LV

                             DAY AND NIGHT

“IT seems to me,” said Claire, “we have lost sight of the hearth that
turns with its lighted firebrands around the lark.”

“On the contrary, we are closer to it than ever. If the sun, which is
thirty-eight millions of leagues from us, were to go around the earth
every day, do you know how far it would have to go in a minute? More
than 100,000 leagues. But this incomprehensible speed is nothing. The
stars, as I have just told you, are so many suns, comparable to ours in
volume and brilliancy; only they are much farther away, and that is what
makes them appear so small. The nearest is about thirty thousand times
as distant as the sun. Accordingly, in order to go around the earth in
twenty-four hours, as it appears to do, it would have to move at the
rate of thirty thousand times 100,000 leagues a minute. And how would it
be with other stars a hundred times, a thousand times, a million times
farther away—stars which, despite their distance, would all have to
accomplish their journey around the earth always in exactly twenty-four
hours? And remember, furthermore, the prodigious size of the sun. You
want it, the giant, the colossus, beside which the earth is only a lump
of clay, to circle at an impossible speed in infinite space, in order to
give light and heat to our planet; you want thousands and thousands of
other suns, quite as large and immensely farther off—in a word, the
stars—to accomplish also, with velocities increasing according to the
distance, a daily journey around this humble terrestrial globe! No! no!
such an arrangement is contrary to reason; to allow it is to want to
make the firebrands, the hearth, the whole house, turn around a little
bird on a spit.”

“Then it is the earth that turns, and we turn with it,” Claire again
interposed. “In consequence of this movement the sun and stars seem to
us to move in the opposite direction, like trees and houses when we are
on the train. Since the sun seems to go around the earth from east to
west in twenty-four hours, it is a proof that the earth turns on its
axis from west to east in twenty-four hours.”

“The earth turns in front of the sun in a manner to present its
different parts successively to the rays of that body; it pirouettes on
its axis like a top. Moreover, while it thus rotates in twenty-four
hours, it revolves around the sun in the interval of a year. In playing
with a top you find a good example of two analogous movements executed
together. When the top turns on its point, not moving from the same
place—in short, when it sleeps—it has only the movement of rotation. But
in throwing it in a certain way, you know better than I that it circles
on the ground while turning on its point. In that instance, it
represents in a small way the double movement of the earth. Its rotation
on its point represents the whirling motion of the earth on its axis;
its course on the ground represents the earth’s revolution around the
sun.

“You can familiarize yourself in another way with the double movement of
the terrestrial globe, as follows: place in the middle of a room a round
table, and on that table a lighted candle to represent the sun. Then
circle around the table, pirouetting on your toes. Each of your
pirouettes corresponds to a turn of the earth on its axis, and your
course around the table corresponds to its journey around the sun.
Notice that in turning on your toes you present in succession to the
rays of the candle the front, one side, the back, and the other side of
your head, which in our experiment may represent the terrestrial globe;
so that each one of its parts is in turn in the light or in the shade.
The earth does the same: in turning it presents one after the other its
different regions to the rays of the sun. It is day for the region that
sees the sun, night for the opposite region. That is the very simple
cause of day and night. In twenty-four hours the earth makes one
rotation on its axis. Of these twenty-four hours the duration of the day
and night is composed.”

“I understand very well the cause of the alternation of day and night,”
said Jules. “It is day for the half of the earth that sees the sun,
night for the opposite half. But as the globe turns, each country comes
in succession to face the sun while others pass into the unlighted half.
The lark that turns on the hearth presents, in the same way, each of its
sides in turn to the heat of the flame.”

“One might almost say,” remarked Emile, “it is day for the half of the
lark next to the fire, and night for the other half.”

“One difficulty still perplexes me,” Jules continued. “If the earth
turns around once in every twenty-four hours, in half of that time we
ought to make a half-turn with the globe that carries us, and find
ourselves upside-down. At this moment we have our heads up, feet down;
twelve hours later it will be just the opposite: our heads will be down
and our feet up. We are upright, we shall be upside-down. In that
inconvenient position why don’t we feel uncomfortable? Why are we not
thrown down? So as not to fall, it seems to me, we ought to be obliged
to cling to the ground in desperation.”

“Your observation is right,” returned Uncle Paul, “but only in a certain
degree. Yes, it is true that twelve hours from now we shall be in an
inverse position; our heads will be toward that point in space to which
our feet are now turned. But despite this inversion there will be no
danger of our falling, nor even the slightest inconvenience of any kind;
for our heads will always be up, that is to say toward the sky, since
the sky surrounds the terrestrial globe everywhere; our feet will always
be down, that is to say resting on the ground. Understand thoroughly,
once for all, that to fall is to rush toward the ground, and not into
surrounding space. So that notwithstanding all the evolutions of our
globe, as we are always on the earth, feet on the ground, head toward
the sky, we are always in an upright position, without any unpleasant
feeling, without any danger of falling.”

“Does the terrestrial globe turn very fast?” Emile inquired.

“It turns on its axis once in twenty-four hours. Therefore any point in
its middle region, the region that makes the longest journey, travels in
the same time forty millions of meters, that is to say a journey equal
to the circuit of the earth, or 462 meters a second. That is about the
speed of a cannon-ball as it leaves the cannon’s mouth, or about thirty
times the speed of the fastest locomotive. Mountains, plains, seas,
apparently fixed in their places for time and for eternity, are
perpetually chasing one another in a circle, with the formidable speed
of more than one-tenth of a league a second.”

“And yet everything seems to us to be stationary.”

“Without the jolting of the car should we not think we were standing
still when the train carries us with such frightful speed? Well, the
rapid movement of the earth is at the same time so gentle that it is
impossible to be aware of it except by the apparent motion of the
stars.”

“By rising to a certain height in a balloon,” said Jules, “we ought to
see the earth turning under us. Seas and their islands, continents with
their empires, forests, and mountains, ought in succession to come under
the eyes of the observer, who in twenty-four hours sees the turning of
the whole earth. What a magnificent spectacle that must be! What a
journey, so wonderful and with so little fatigue! When the rotation
brings back one’s own country, one descends and it is accomplished. In
twenty-four hours, without changing place, one has seen the whole
world.”

“Yes, I agree with you, it would be an admirable way to see countries.
To this spot where we are other peoples will come, brought by the
rotation; seas, distant regions, snowy mountains will take our place;
and to-morrow at the same hour we shall be here again. Where we are
talking now, in the shade of the juniper-trees, first will pass the sea,
the somber Atlantic, which will replace our conversation by the grand
voice of its waves. In less than an hour the ocean will be here. Some
large war-vessel, with its triple row of guns, will float perhaps, all
sails set, over the spot we are occupying. The sea has passed. Now we
have North America, the great Canadian lakes, and the interminable
prairies where the red-skinned Indians hunt buffaloes. The sea begins
again, much larger than the Atlantic; it takes nearly seven hours to
pass. What line of islands is this where fishermen wrapped in furs are
drying herrings? They are the Koorile Isles, south of Kamchatka. They
pass quickly; we scarcely have time to give them a glance. Now it is the
turn of the yellow-faces—the Mongolians and Chinese, with slanting eyes.
Oh! what curious things we could see here! But the ball is always
turning, and China is already in the distance. The sandy plateaus of
Central Asia and mountains higher than the clouds come next. Here are
the pastures of the Tartars, with neighing herds of mares; here are the
grassy plains of the Caspian with the flat-nosed Cossacks; then southern
Russia, Austria, Germany, Switzerland, and finally France. Let us
descend quickly, get on to our feet; the earth has finished its
rotation.

“Do not for an instant, my little friends, think that this giddy
spectacle of the earth passing with the rapidity of a cannon-ball would
be visible to any but spiritual eyes. By rising into the upper air in a
balloon, as Jules said, it does at first seem as if we ought to see the
earth turning and lands and seas passing under our feet. Nothing of the
kind takes place, for the atmosphere turns with the terrestrial globe
and drags the balloon in the general rotation, instead of leaving it at
rest, as would be necessary if the observer were to have successively
under his eyes the different regions of the earth.”

                              CHAPTER LVI

                        THE YEAR AND ITS SEASONS

“YOU told us,” said Claire, “that at the same time the earth turns on
its axis it travels round the sun.”

“Yes. It takes three hundred and sixty-five days for that journey; it
makes three hundred and sixty-five pirouettes on its axis in
accomplishing a journey round the sun. The time spent in this journey
makes just a year.”

“The earth takes one day of twenty-four hours to turn on its axis; one
year to turn round the sun,” said Jules.

“That is it. Imagine yourself turning around a circular table the center
of which is occupied by a lamp representing the sun, while you represent
the earth. Each of your walks around the table is one year. To represent
things exactly, you must turn on your heels three hundred and sixty-five
times while you circle the table once.”

“It is as if the earth waltzed around the sun,” Emile suggested.

“The comparison is not so well chosen as it might be, but it is exact.
It shows that in spite of the giddiness of his age Emile has understood
perfectly. A year is divided into twelve months which are: January,
February, March, April, May, June, July, August, September, October,
November, December. The unequal length of the months is sometimes
confusing. Some have 31 days, others 30; February has 28 or 29,
according to the year.”

“For my part,” said Claire, “I should find it hard to tell whether May,
September, and other months have 30 or 31 days. How can one remember
which months have 31 days and which 30?”

“A natural calendar, engraved on our hands, teaches us in a very simple
way. Close the fist of the left hand. At the knuckles the four fingers,
other than the thumb, from each a bump, separated by a hollow from the
next bump. Place the index finger of the right hand in turn on these
bumps and hollows, beginning with the little finger, and at the same
time name the months of the year in order: January, February, March,
etc. When the series of the four fingers is exhausted, return to the
starting-point and continue naming the twelve months on the bumps and
hollows. Well, all the months corresponding to the bumps have 31 days;
all those corresponding to the hollows, 30. You must except February,
answering to the first hollow. That has 28 or 29 days, according to the
year.”

“Let me try,” proposed Claire. “We’ll see how many days May has:
January, bump; February, hollow; March, bump; April, hollow; May, bump.
May has 31 days.”

“It is as easy as that,” said her uncle.

“My turn now,” interposed Jules. “Let us try September: January, bump;
February, hollow; March, bump; April, hollow; May, bump; June, hollow;
July, bump. And now? I am at the end of my hand.”

“Now begin again and go on naming the months,” Uncle Paul instructed
him.

“You go on at the same point where you began?”

“Yes.”

“All right. August, bump. There are two bumps in succession. There are
then two months together, July and August, that have 31 days?”

“Yes.”

“I will begin again. August, bump; September, hollow. September has 30
days.”

“Why has February sometimes 28 and sometimes 29 days?” asked Claire.

“I must tell you that the earth does not take exactly 365 days to turn
around the sun. It takes nearly six hours more. To make up these six
hours that were disregarded at first in order to have a round number of
days in the year, they are reckoned in every four years, and the
additional day they make all together is added to February, which then
becomes 29 days long instead of 28.”

“So, for three years running, February has 28 days, and the fourth year
it has 29.”

“Exactly. Remember, too, that the years when February has 29 days are
called leap years.”

“And the seasons?” queried Jules.

“For reasons that would be a little too difficult for you to understand
yet, the annual journey of the earth around the sun causes the seasons
and the unequal length of days and nights.

“There are four seasons, of three months each: spring, summer, autumn,
and winter. Spring is from about March 20th to June 21st; summer from
June 21st to September 22d; autumn from September 22d to December 21st;
winter from December 21st to March 20th.

“On March 20th and September 22d the sun is visible 12 hours and
invisible 12 hours, from one end of the earth to the other. The 21st of
June is for us the time of the longest days and shortest nights; the sun
is visible sixteen hours and invisible eight hours. Farther north the
length of the day increases and that of the night diminishes. There are
countries where the sun, an earlier riser than here, rises at two
o’clock in the morning and sets at ten o’clock at night; still others
where the time of its rising and that of its setting are so close
together that the sun has hardly sunk below the apparent edge of the sky
before it appears again. Finally, at the very pole of the earth, that is
to say at the point that remains stationary, like the end of the axle of
a wheel, while all the rest turns, one could witness the wonderful
spectacle of a sun that does not set, that turns around the spectator
for six whole months, equally visible at midnight and midday. In those
countries there is no longer any night.

“On the 21st of December we have a state of affairs just the reverse of
that observed in June. With us the sun rises at 8 o’clock in the
morning; at four in the afternoon it has already set. That is eight
hours of day for sixteen of night. Farther north there are now nights of
18, 20, 22 hours, and corresponding days of six, four, and two hours. In
the neighborhood of the pole, the sun does not even show itself, and
there is no longer any daylight; for six months there is the same
darkness in the middle of the day as at midnight.”

“And do people live in that country of the pole, where the year is
composed of a day lasting six months and a night of six months?” asked
Jules.

“No, up to this time[2] man has not been able to reach the pole on
account of the horrible cold there; but there are countries more or less
near the pole which are inhabited. When winter comes, wine, beer, and
other beverages turn into blocks of ice in their casks; a glass of water
thrown into the air falls back in flakes of snow; the moisture of the
breath becomes needles of rime at the opening of the nostrils; the sea
itself freezes to a great depth and thus increases the apparent extent
of the dry land, which it resembles, having, like it, its fields of snow
and mountains of ice. For whole months the sun does not show itself, and
there is no difference between day and night, or rather it is one long
night, the same at midday as at midnight. However, when the weather is
fine darkness is not complete; the light of the moon and stars,
augmented by the whiteness of the snow, produces a kind of semi-daylight
sufficient for seeing. By this wan light, in sledges drawn in disorderly
fashion by teams of dogs, the people of these dark regions hunt what
scanty game there is. Fishing furnishes them more abundant food. Fish,
dried, stored, half decayed, and rancid whale’s blubber are their
habitual food. For fuel for their hearths their dependence is, again, on
their fishing, which supplies them with fish-bones and slices of
blubber. Here, in short, wood is unknown; no tree, however hardy, can
resist the rigors of winter. Willows, birches, dwarfed to insignificant
underbrush, venture as far as the southern extremities of Lapland, where
the cultivation of barley, the hardiest of cultivated plants ceases.
Beyond this point all woody vegetation ceases; and during the summer
there are found only occasional tufts of grass and moss, hastily
ripening their seeds in the sheltered hollows of the rocks. Further on
the summer is too short for the snow and ice to melt completely; the
ground is never bare, and all vegetation is impossible.”

Footnote 2:

  This was written before Peary’s and Amundsen’s achievements in polar
  exploration.—_Translator._

[Illustration: A part of the moon’s surface]

“Oh, the doleful countries!” cried Emile. “One more question, Uncle. In
traveling around the sun does the earth go fast?”

“It takes a year for the entire tour; but as it circles at an enormous
distance from the sun, a distance of 38 millions of leagues, it must
travel this wide circle with a speed beyond your power to conceive. This
speed is 27,000 leagues an hour. In the same time the fastest locomotive
goes about 15 leagues. Compare and judge.”

“What!” exclaimed Jules, “the immense ball of which we have never been
able to comprehend the frightful weight travels in the sky with such
rapidity?”

“Yes, my friend; with a speed of twenty-seven thousand leagues an hour
the terrestrial ball goes rolling through space, without axle, without
support, always on the ideal line that has been given it for its
race-track. Who caused it to move so rapidly that the very thought of it
makes you feel giddy? Let us bow the head, my children; it is the power
of God.”

                              CHAPTER LVII

                           BELLADONNA BERRIES

BAD news was circulating from house to house in the village. Here is
what they were saying:

That day they had put little Louis into his first trousers. They had
pockets and shiny buttons. In his new costume Louis was a little
awkward, but much pleased. He admired the buttons that shone in the sun;
he kept turning his pockets inside out to see if there was room enough
for all his playthings. What made him the happiest was a tin watch,
always marking the same hour. His brother, Joseph, two years older, was
also much pleased. Now that Louis was dressed like him, nothing
prevented his taking him to the woods, where there were birds’ nests and
strawberries. They owned in common a lamb whiter than snow, with a
pretty little bell at its neck. The two brothers were to take it to the
meadow. Some lunch was packed in a basket. They kissed their mother, who
advised them not to go far. “Take care of your brother,” said she to
Joseph; “hold him by the hand and come back soon.” They started. Joseph
carried the basket, Louis led the lamb. From the door their mother
watched them going off, herself happy in their joy. Every now and then
the children turned to smile at her; then they disappeared at the turn
of the path.

They reach the meadow. The lamb frolics on the grass; Joseph and Louis
run after butterflies in the midst of a clump of tall trees.

“Oh, the beautiful cherries!” exclaimed Louis, suddenly; “see how big
and black they are! Cherries, cherries! We are going to have a feast.
Let us pick some to eat.”

There were, in fact, some large berries of a dark violet hue on low
plants.

“How small these cherry-trees are!” answered Joseph. “I have never seen
any like them. We shan’t have to climb the tree for them, and you won’t
tear your new trousers.”

Louis picked one of the berries and put it into his mouth. It was
insipid and sweetish.

“These cherries are not ripe,” says little Louis, spitting it out.

“Take this one,” answers Joseph, giving him one that felt very soft. “It
is ripe.”

Louis tastes it and spits it out.

“No, they are not at all good,” repeats the little boy.

“Not good, not good?” says Joseph; “you will see.” He eats one, then
another, then another still, then a fourth, then a fifth. At the sixth
he is obliged to stop. Decidedly they were not good.

“It is true, they are not very ripe. But let’s pick some, all the same.
We’ll let them ripen in the basket.”

They gathered a handful or two of these black berries, then began
running after butterflies. The cherries were forgotten.

An hour later, Simon, who was returning from the mill with his donkey,
found two little children seated at the foot of the hedge, crying aloud
and clasping each other. At their feet a lamb was lying and bleating
plaintively. And the younger was saying to the other: “Joseph, get up;
we will go home.” The elder tried to rise, but his legs, seized with a
convulsive trembling, could not support him. “Joseph, Joseph, speak to
me,” said the poor little one; “speak to me.” And Joseph, his teeth
chattering, looked at his brother with eyes so big they frightened him.
“There is one more apple in the basket; would you like it? I will give
you all of it,” went on the little fellow, his cheeks bathed in tears.
And the elder trembled and then became rigid, by fits and starts, and
stared fixedly with eyes growing ever larger and larger.

It was then that Simon passed. He put the two children on the donkey,
took the basket, and, followed by the lamb, hastened to the village.

When the unhappy mother saw Joseph, her dear Joseph, so well a few hours
before, so rejoiced at taking his brother for a walk, and now
unconscious, dying, it was a scene to melt the heart. “My God, my God!”
cried she, crazed with grief, “take me and leave my son! Oh, my Joseph!
Oh, my poor Joseph!” And, covering him with kisses, she burst into cries
of despair.

The doctor was summoned; the basket in which were still some of the
black berries mistaken for cherries explained to him the cause of the
sad event. “Deadly nightshade, great God!” he exclaimed under his
breath. “Alas! It is too late.” Broken-hearted, he ordered a potion, the
efficacy of which he could not count on, for the poison had made
irreparable progress. And, in fact, an hour later, while the mother, on
her knees at the foot of the bed, was praying and weeping, a little hand
was stretched out from under the coverings and placed all cold in hers.
It was the last good-by: Joseph was dead.

The next day they buried the poor little one. The whole village attended
the funeral. Emile and Jules returned from the cemetery so sad that for
several days they did not think of asking their uncle the cause of this
lamentable accident.

Since then, in the house of mourning, little Louis stops playing every
now and then and begins to cry, despite his beautiful tin watch. He has
been told that Joseph has gone far away and that he will come back some
day. “Mother,” he says sometimes, “when will Joseph come back? I am
tired of playing alone.” His mother kisses him and, covering her face
with a corner of her apron, sheds hot tears. “Don’t you love Joseph any
more, and is that why you cry when I speak of him?” asks the poor little
innocent. And his mother, overwhelmed, tries in vain to stifle her sobs.

                             CHAPTER LVIII

                            POISONOUS PLANTS

THE death of poor Joseph had spread consternation through the village.
If children left the house and went off into the fields, there was
constant anxiety until they returned. They might find poisonous plants
that would tempt them with their flowers or their berries, and poison
them. Many said, with reason, that the best way to prevent these
terrible accidents was to know the dangerous plants and teach the
children to beware of them. They went and found Maître Paul, whose great
knowledge was appreciated by all, and asked him to teach them the
poisonous plants of the neighborhood. So Sunday evening there was a
numerous gathering at Uncle Paul’s. Besides his two nephews and his
niece, Jacques and Mother Ambroisine, there were Simon, who had come
upon the two unfortunate children on his way home from the mill, Jean
the miller, André the plowman, Philippe the vine-dresser, Antoine,
Mathieu, and many others. The day before, Uncle Paul had taken a walk in
the country to gather the plants he was to talk about. A large bunch of
the principal poisonous plants, some in blossom, others with berries,
were in a pitcher of water on the table.

“There are people, my friends,” he began, “who shut their eyes so as not
to see danger, and think themselves safe because they wilfully ignore
peril. There are others who inform themselves about what may be a menace
to them, persuaded that one warned person may be worth two unwarned. You
belong to this latter class, and I congratulate you. Countless ills lie
in wait for us; let us try to diminish their number by our vigilance,
instead of giving ourselves up to lazy carelessness. Now that a
frightful misfortune has overtaken one of our families, who does not
realize the extreme importance of our all knowing, so as to avoid them,
these terrible plants that claim victims every year? If this knowledge
were more extended, the poor little fellow whose loss we now lament
would still be his mother’s consolation. Ah! unfortunate child!”

[Illustration: Belladonna]

Uncle Paul, whom thunder never caused even to knit his brows, had tears
in his eyes and his voice trembled. The good Simon, who had seen the two
children in each other’s arms under the hedge, felt more moved than the
others at this recollection. He pulled down the broad rim of his hat to
hide the big tears that were rolling down his rough cheeks bronzed by
the sun. After a few moments of silence Uncle Paul continued:

“The death of the unfortunate little boy was caused by belladonna. It is
a rather large weed with reddish bell-shaped flowers. The berries are
round, purplish-black, and resemble cherries. The leaves are oval and
pointed at the end. The whole plant has a nauseous odor and a somber
appearance, as if to announce the poison it conceals. The berries
particularly are dangerous because they may tempt children by their
resemblance to cherries and their sweetish taste. Enlargement of the
pupil of the eye and a dull, fixed stare are the characteristics of
belladonna poisoning.”

Paul took from the bouquet in the pitcher a sprig of belladonna, and
passed it around in the audience so that each one could examine the
plant closely.

“What do you say that is called?” asked Jean.

“Belladonna.”

“Belladonna; good. I know that weed. I have often found it near the
mill, in shady places. Who would believe those pretty cherries held such
a frightful poison.”

Here André asked: “What does the word belladonna mean?”

“It is an Italian word meaning fine lady. Formerly, it seems, ladies
used the juice of this plant to keep their complexion white.”

“That is a property that does not concern our brown skin. What concerns
us is this confounded berry which may tempt our children.”

“Are not our herds in danger when this weed grows in pastures?” Antoine
next inquired.

“It is very seldom that animals touch poisonous plants; they avoid
browsing what might harm them, warned by the odor, and above all by
instinct.

“This other plant with large leaves, whose flowers, red on the outside
and spotted on the inside with white and purple, are arranged in a long
and magnificent cluster almost as high as a man, is called digitalis.
The flowers have the form of long, tun-bellied bells, or rather of
glove-fingers; therefore it is called by different names, all referring
to this peculiarity.”

[Illustration: Fox-glove]

“If I am not mistaken,” said Jean, “it is what we call fox-glove. It is
common on the edges of woods.”

“We call it fox-glove on account of its resemblance to the thumb of a
glove. For the same reason it has elsewhere the name of gloves of
Notre-Dame, gloves of the Virgin, and finger-stall. The name digitalis,
borrowed from the Latin, also refers to the finger-shaped flower.”

“It is a great pity that fine plant is poisonous,” commented Simon; “it
would be a pleasure to see it in our gardens.”

“It is, indeed, cultivated as an ornamental plant, but in gardens under
stricter vigilance than ours. As for us, my friends, who hardly have
time to watch over flowers, we shall do well not to put digitalis within
reach of children by introducing it in our gardens. The whole plant is
poisonous. It has the singular property of slowing up the beating of the
heart and finally stopping it. It is unnecessary to tell you that when
the heart no longer beats, all is over.

[Illustration: Hemlock]

“Hemlock is still more dangerous. Its finely-divided leaves resemble
those of chervil and parsley. This resemblance has often occasioned
fatal mistakes, all the easier, because the formidable plant grows in
the hedges of enclosures and even in our gardens. A plain enough
characteristic, however, enables us to distinguish the poisonous weed
from the two pot-herds that resemble it: that is the odor. Rub that tuft
of hemlock in your hands, Simon, and smell.”

“Ouf!” said Simon, “that smells very bad; parsley and chervil have not
that horrid odor. When one is warned, no mistake can be made, in my
opinion.”

“Yes, when one is warned; but those who are not take no account of the
smell and mistake hemlock for parsley or chervil. It is in order to be
warned that you are listening to me this evening.”

“You are doing us a great service, Maître Paul,” said Jean, “by putting
us on our guard against these dangerous plants. Every one at home ought
to know what you have just taught us, so as not to gather a salad of
hemlock instead of chervil.”

[Illustration: Arum]

“There are two kinds of hemlock. One, called the great hemlock, is found
in damp and uncultivated places. It is very like chervil. Its stems are
marked with black or reddish spots. The other, called the little
hemlock, resembles parsley. It grows in cultivated fields, hedges, and
gardens. Both have a nauseating odor.

“Now here is a poisonous plant very easy to recognize. It is the arum,
or, as it is commonly called, cuckoopint or calves’-foot. The arum is
common in hedges. The leaves are very broad and shaped like a large
lance-head. The blossom is shaped like a donkey’s ear. It is a large
yellowish trumpet, from the bottom of which rises a fleshy rod that
might be taken for a little finger of butter. This strange flower is
succeeded by a bunch of berries as large as peas and of a splendid red
color. The whole plant has an unbearable burning taste.”

“Let me tell you, Maître Paul,” put in Mathieu, “what happened one day
to my little Lucien. Coming home from school, he saw in the hedge those
large flowers you are speaking of, like donkey’s ears; the fleshy rod in
the middle looked to him like something good to eat. You have just
compared it to a little finger of butter. The thoughtless creature was
taken with its looks. He bit into the deceitful finger of butter. What
had he done! In a moment his tongue began to burn as if he had bitten a
red-hot coal. I saw him come home spitting and making faces. He won’t be
taken in again, you may be sure. Luckily he hadn’t swallowed the piece.
The next morning he was all right.”

“A similar burning flavor is found in the white milk-like juice that
runs from the euphorbia when cut. The euphorbia are plants of mean
appearance, very common everywhere. Their flowers, small and yellowish,
grow in a head, the even branches of which radiate at the top of the
stem. These plants are easily recognized by their white juice, their
milk, which runs in abundance from the cut stems. This juice is
dangerous, even on the skin alone, if it is tender; its acrid, burning
taste is its sufficient characteristic.

[Illustration: Aconites]

“The aconites, like digitalis, are fine plants which for their beauty
have been introduced in gardens, notwithstanding the violence of their
poison. They are found in hilly countries. Their blossoms are blue or
yellow, helmet-shaped, and grow in an elegant terminal bunch of the
finest effect. Their leaves, of a lustrous green, are cut out in
radiating sprays. The aconites are very poisonous. The violence of their
poison has given them the name of dog’s-bane and wolf’s-bane. History
tells us that formerly arrow-heads and lance-heads were soaked in the
juice of the aconites, to poison the wounds made in war and to make them
mortal.

“There is sometimes cultivated in our gardens a shrub with large shiny
leaves, which do not fall in winter, and with black, oval berries as
large as acorns. It is the cherry-bay. All its parts, leaves, flowers,
and berries, have the odor of bitter almonds and peach kernels. The
leaves of the cherry-bay are sometimes used to give their perfume to
cream and milk products. They should be used only with great prudence,
for the cherry-bay is extremely poisonous. They even say one has only to
remain some time in its shade to become indisposed from its exhalations
of a bitter-almond odor.

“In autumn there is seen in abundance, in damp fields, a large and
beautiful flower, rose or lilac in color, that rises from the ground
alone, without stem or leaves. It is the colchicum, called also meadow
saffron, or _veillotte_, also _veilleuse_, because it blossoms on the
eve of the cold season. If you dig a little way down, you will find that
this flower starts from a rather large bulb, covered with a brown skin.
Colchicum is poisonous; so cows never touch it. Its bulb is still more
poisonous.

“But we have talked enough about harmful plants for to-day. I should be
afraid of befogging your memories were I to enter into more details.
Next Sunday I will expect you again, my friends, and will talk to you
about mushrooms.”

                              CHAPTER LIX

                              THE BLOSSOM

YES, they had listened very attentively the day before when Uncle Paul
told them all about poisonous plants. Who would not listen to a talk on
flowers? Jules and Claire, however, would have been glad to hear more.
How are the flowers made that their uncle showed them yesterday? What is
to be seen inside them? Of what use are they to the plant? Under the big
elder-tree in the garden their uncle talked to them as follows:

“Let us begin with the blossoms of the digitalis, which I spoke of
yesterday. Here is one. It has, as you see, almost the form of a
glove-finger, or better, of a long pointed cap. Emile could put one on
to his little finger; there would be plenty of room. It is purplish-red
in color. Inside, it has spots of dark red encircled with white. The red
glove-finger rises from the center of a circle of five little leaves.
These little leaves are also part of the flower. Together they form what
is called the calyx. The rest, the red part, is called the corolla.
Remember these words, which are new to you.”

“The corolla is the colored part of the flower; the calyx is the circle
of little leaves at the base of the corolla,” repeated Jules.

“Most flowers have two envelopes like these, one within the other. The
exterior, or calyx, is nearly always green; the interior, or corolla, is
embellished with those magnificent tints that please us in so many
flowers.

[Illustration: Mallow]

“In the mallow, which you see here, the calyx consists of five little
green leaves, and the corolla of five large pieces of lilac rose-color.
Each of these pieces is called a petal. The petals, all together, make
the corolla.”

“The corolla of the digitalis has only one piece or petal; that of the
mallow has five,” remarked Claire.

“It looks that way at first, but on examining closely you will find that
they both have five. I must tell you that in a great many flowers the
petals unite as soon as they begin to form in the bud, and by their
union constitute a corolla which looks like only one piece. But very
often the united petals separate a little at the edge of the flower, and
by indentations more or less deep show how many are joined together.

“Look at this tobacco blossom. The corolla forms a tun-bellied funnel,
apparently composed of only one piece. But the edge of the flower is cut
out in five similar parts, which are the extremities of so many petals.
The tobacco blossom, then, has five petals, the same as the mallow;
only, these five petals, instead of being separate all their length, are
welded together in a sort of funnel.

[Illustration: Tobacco]

“Corollas with separate petals are called polypetalous corollas.”

“Like that of the mallow,” suggested Claire.

“And that of the pear, almond, and strawberry,” added Jules.

“Jules forgets some very pretty ones: the pansy and violet,” said Emile.

“Corollas with petals all joined together are called monopetalous
corollas,” continued Uncle Paul.

“For example, digitalis and tobacco,” said Jules.

“And the bell-flowers, don’t forget them, the beautiful white
bell-flowers that climb the hedges,” Emile added.

“The five petals joined together are just as easily distinguishable in
this flower we have here, called snap-dragon.”

“Why is it called snap-dragon?” asked Emile.

“Because when it is pressed on both sides it opens its mouth like an
animal.”

Uncle Paul made the flower yawn; under pressure of his fingers it opened
and shut its mouth as if biting. Emile looked on in amazement.

“In this mouth there are two lips, upper and lower. Well, the upper lip
is split in two by a deep indentation, the sign of two petals, and the
lower lip is split in three, indicating three petals. The corolla of the
snap-dragon, although apparently all in one piece, is therefore in
reality composed of five petals welded together.”

[Illustration: Snap-dragon]

“There are, then,” said Claire, “five petals in the mallow, pear,
almond, digitalis, tobacco, and snap-dragon, with this difference, that
the five petals are separate in the mallow, pear, and almond, and welded
together in the digitalis, snap-dragon, and tobacco.”

“Five petals, either separate or united,” Uncle Paul went on, “are found
in a great many other flowers.

“Let us come back to the calyx. The little green leaves of which it is
composed are called sepals. There are five in the different flowers we
have just examined, five in the mallow, five in tobacco, five in
digitalis, five in the snap-dragon. Like the petals, the parts of the
calyx, or sepals, sometimes remain separate, sometimes join together,
but generally leave some indentations showing their number.

“The calyx having its parts distinct from one another is called a
polysepalous calyx. That of the digitalis and of the snap-dragon is of
this class.

“The calyx with sepals united is known as a monosepalous calyx. Such is
that of the tobacco blossom. By the five indentations at its edge one
can easily see that it is formed of five pieces joined together.”

“The number five occurs again and again,” observed Claire.

“A flower, my child, is beyond doubt a wonderful thing of beauty, but
especially is it a masterpiece of wise construction. Everything about it
is calculated according to fixed rules, everything arranged by number
and measure. One of the most frequent arrangements is in sets of five.
That is why we have just found five petals and five sepals in all the
flowers examined this morning.

“Another grouping that often occurs is that in threes. It is found in
bulb flowers,—the tulip, lily, lily of the valley, etc. These flowers
have no green covering or calyx; they have only a corolla composed of
six petals, three in an inner circle, three in an outer.

“The calyx and the corolla are the flower’s clothing, a double clothing
having both the substantial material that guards from inclemency, and
the fine texture that charms the eye. The calyx, the outer garment, is
of simple form, modest coloring, firm structure, suitable for
withstanding bad weather. It has to protect the flower not yet opened,
to shield it from the sun, from cold, and wet. Examine the bud of a rose
or mallow; see with what minute precision the five sepals of the calyx
are united to cover the rest. Not the slightest drop of water could
penetrate the interior, so carefully are their edges joined together.
There are flowers that close the calyx every evening as a safeguard
against the cold.

“The corolla or inner garment unites elegance of form and richness of
tint with fineness of texture. It is to the flower what wedding garments
are to us. That is what especially captivates our eye, so that we
commonly consider it the most essential part of the flower, while it is
really only a simple ornamental accessory.

“Of the two garments, the calyx is the more necessary. Many flowers, of
severe taste, know how to dispense with the pleasing part, the corolla;
but they are very careful not to renounce the useful, the calyx, which,
in its simplest form, is reduced to a tiny little leaf like a scale.
Flowers without corolla remain unseen, and the plants that bear them
seem to us to have no blossoms. It is a mistake: all trees and plants
bloom.”

“Even the willow, oak, poplar, pine, beech, wheat, and so many others
whose blossoms I have never seen?” asked Jules.

“Even the willow, oak, and all the others. Their blossoms are extremely
numerous, but, as they are very small and have no corolla, they escape
the inattentive eye. There is no exception: every plant has its
blossom.”

                               CHAPTER LX

                                 FRUIT

“IT would be knowing a person very little only to be aware of his
wearing a garment of a certain material, a coat of such and such a
cloth. One does not know a flower any better when one knows that it is
clothed with a calyx and a corolla. What is under this covering?

[Illustration: A flowering branch of the Gillyflower]

“Let us examine together this gillyflower. It has a calyx of four sepals
and a corolla of four yellow petals. I take away these eight pieces.
What is left now is the essential part; that is to say, the thing
without which the flower could not fill its rôle and would be perfectly
useless. Let us go carefully over this remaining part. You will find it
well worth the trouble.

“First, there are six little white rods, each one surmounted by a bag
full of yellow powder. These six pieces are called stamens. They are
found in all flowers in greater or less number. The gillyflower has six,
four longer ones arranged in pairs, and two shorter.

“The double bag that surmounts the stamen is called an anther. The dust
contained in the anther is known as pollen. It is yellow in the
gillyflower, lily, and most plants; ashy gray in the poppy.”

“You have already told us,” Jules interposed, “how clouds of pollen,
raised by the wind in the woods, are the cause of supposed showers of
sulphur that frighten people so.”

“I take away the six stamens. There remains a central body, swollen at
the bottom, narrow at the top, and surmounted by a kind of head wet with
a sticky moisture. In its entirety this central body takes the name of
pistil; the swelling at the bottom is called an ovary, and the sticky
head that terminates it is a stigma.”

“What big names for such little things!” exclaimed Jules.

“Little, yes; but of unparalleled importance. These little things, my
dear friend, give us our daily bread; without the miraculous work of
these little things we should die of hunger.”

“I will take care to remember their names, then.”

“I, too,” chimed in Emile; “but you must go over them again, they are so
hard to learn.”

Uncle Paul began again. Jules and Emile repeated after him: stamen,
anther and pollen; pistil, stigma and ovary.

“With a penknife I divide the flower in two. The split ovary shows us
what is inside.”

“I see little seeds in regular rows in two compartments,” observed
Jules.

“Do you know what those hardly visible seeds are?”

“Not yet.”

“They are the future seeds of the plant. The ovary, then, is the part of
the plant where the seeds form. At a certain time the flower withers;