Rollo in Naples Part 12

Mrs. Gray got out of her chair as soon as the men put it down, and went to Rosie's chair to ask Rosie how she had got along.

"Very well indeed," said Rosie. "I like it very much."

"Does your courage hold out to go up the cone?" asked Mrs. Gray.

"O, yes, mother," said Rosie; "and I wish you would go up too."

"No," replied Mrs. Gray; "I will go back to the Hermitage, and wait there until you come down. But you may go up if you wish, and if Mr.

George is willing to take you."

Mr. George said that he should like to have Rosie go very much, and he promised to take special care of her. So the new bearers lifted her up upon their shoulders again, and the strapmen that Philippe had provided came with their straps to Rollo and Josie. Mr. George took a cane which one of the boys provided him with, and thus the party began the ascent of the cone.

[Ill.u.s.tration: THE ASCENT.]

Rollo found, after a while, that he did not need the strapmen; so he let Josie have them both. Josie put his staff through the loops of the straps, and took hold of the ends of it, while the men walked before him, and pulled him up the rocks.

Rollo kept ahead. He climbed faster than the rest of the train, but he stopped now and then on some projecting ma.s.s of lava to wait for them to come up. Next to Rollo came Josie, with the two strapmen pulling him up by their straps. Then the refreshment man, with his basket of provisions on his head. Last of all came the bearers of the portantina, with Rosie in the chair. Mr. George followed immediately after. He kept close to Rosie all the way, for he thought she would be afraid to be left alone with such wild and rough-looking men.

Indeed, she doubtless would have been afraid, for the men were rough and wild in their demeanor, as well as in their looks. They made a great deal of noise, shouting and scolding all the way. Every now and then they would stop to rest, and then they would clamor for _buono manos_, sometimes begging for the money in very earnest and noisy, but suppliant tones, and sometimes demanding it in a very loud and threatening manner.

Mr. George, however, paid no heed to these requests, but steadily refused to give the men any money, saying simply that Philippe would pay. At length the men, finding that Mr. George was cool and collected, and that he did not seem to be at all intimidated by their violent and boisterous demeanor, became quiet, and performed their duty in a more steady and orderly manner.

The party went on climbing in this way for nearly an hour, and finally reached the summit.

CHAPTER VII.

THE SUMMIT.

On coming out upon the brow of the mountain, Rollo saw at a short distance before him an immense column of dense white vapor pouring up into the air. His first impulse was to run forward up the sandy slope that still remained between the place where he stood and the margin of the crater; but he checked himself, and stopped where he was, to wait for the rest of the party. As soon as the portantina bearers reached the place where he stood, they set down the chair, and immediately the whole set crowded around Mr. George, and again demanded _buono manos_.

"_Philippe payera_," said Mr. George, pointing down the mountain to the Hermitage--"_Philippe payera, la bas_," which means, "Philippe will pay when you go down."

Mr. George said this in a very quiet manner, and then proceeded to help Rosie out of her chair. The guide who had come up the mountain with them then led the way, and Mr. George, Rollo, Rosie and Josie followed, towards the crater.

And here I must stop a moment in my story to explain a little what a crater is, and how it is formed. A crater is a great circular pit or depression in the top of a volcano, formed by the sinking of the ground in that part. This sinking of the ground is caused apparently by the cooling and shrinking of the melted matter below, after a time when it has been unusually heated.

Most boys have observed an effect similar to this in casting lead. When you attempt to cast any thing of lead,--a cannon, for example, or anchor, or even a bullet,--you will observe that as the lead cools, the portion of it which comes at the top of the mould shrinks and falls in, forming a little pit or depression, which you have to fill up by pouring in a little more lead. The reason is, that lead, as well as most other melted substances, shrinks when it cools. In the case of the bullet, for instance, all the lead which forms the ma.s.s of the bullet within the mould shrinks. The effect of this would be to collapse the sides, were it not that the sides have already become solid by contact with the cold mould. But the lead at the top, having been poured in last, is still fluid; and so that settles down as the lead cools below, and forms the little pit or depression, which the boy presently fills up by pouring in a little more lead.

It is much the same with a volcano. For some reason or other,--no one as yet knows what it is,--the interior of a volcano changes its temperature very much at different times. Sometimes for a period of several months, or years, it seems to be all the time growing hotter and hotter. The substances below become more and more melted, and formed into lava. The water, which is all the time filtering in through the crevices and openings, in the rocks around the sides of the mountain, is forced down under this molten ma.s.s by the immense pressure given to it by the height of the mountain. There it is turned into steam. For a time it is kept down by the vast weight of the lava which is over it, but after a time the elastic force of it gets so great that a bubble of it bursts up, and comes out at the top of the mountain in a great, thundering puff, bringing up some portion of the melted lava with it, and throwing it high into the air.

The lava thus thrown up falls down again, and when there is no wind it falls down close around the opening. Some of it falls _into_ the opening, where it is melted again. The rest falls on the sides, and in process of time it begins to build up a small hill, as it were, all around the opening, though the puffs and explosions of steam that are continually coming out keep a mouth open at the top.

Things go on in this way for some time, until at length, for some mysterious reason which n.o.body understands, the interior of the mountain begins to moderate its heat, and finally to grow cool--not entirely cool, but cooler than it has been. The puffs and explosions gradually cease. The lava within the bowels of the mountain shrinks as it cools.

The sides of the mountain being firm and solid, do not collapse; but the top, being still more or less soft, falls in, not suddenly, but by a slow and gradual motion, corresponding with the progress of the cooling below. So slow, indeed, is this progress, that sometimes the ground continues sinking slowly in this way for several years before the crater is fully formed.

All this time, although the puffs and explosions have in a great measure ceased, the steam continues to blow out, more or less steadily, from a great many small openings, some of them in the bottom of the crater, and some, perhaps, in the sides. This steam is changed into visible vapor when it comes out where the air is cool, and the several streams, mingling together as they rise into the air, form a cloudy column, which is often called _smoke_. Strictly speaking, however, it is not smoke.

It is almost entirely composed of steam.

After continuing in this state for some time, the interior of the mountain begins to grow hot again. Then the steam and hot lava begin to puff out at some one or other of the vents in the bottom of the crater.

If the heating goes on, the lava comes out hotter and hotter from the opening, and by melting away the sides of it and blowing it out, it gradually enlarges it. The lava that is blown out, too, falls down all around the hole, and gradually builds up a mound around it, like a little dome, while the successive blasts keep the outlet open all the time at the top. This small cone, rising up gradually thus, in the bottom of the crater formed by the sinking in of the mountain before, and the chimney opening up through the centre of it, gives vent to all the steam from below, while a great many of the other orifices are stopped up by the lava which comes up out of the great opening falling into them. After a time, the lava that is thrown out spreads over the whole floor of the crater in a ma.s.s of black, corrugated slag, with the small cone rising from the centre of it, and the opening at the top glowing like the mouth of a fiery furnace, and bursting out every now and then, with explosions of steam, and red-hot stones, and melted lava.

This was precisely the condition of Vesuvius at the time that Rollo visited it. The top of the mountain had fallen in, in two places, some time before, on account of the cooling below, and two great craters had been formed. Now, the furnace had been for some time heating up again, and in each crater a black cone, with a fiery mouth open at the apex of it, was gradually growing up, and covering the whole floor of the crater with the black and molten matter which it was ejecting.

It was to the edge of one of these craters that the party now advanced, and the engraving will give you some idea of the view which it presented.

[Ill.u.s.tration: VIEW OF THE CRATER.]

There were several persons, both ladies and gentlemen, standing on the margin of the crater when our party arrived. Mr. George led Rosie to the place, and looked down with her into the abyss. The sides of it were formed of precipitous cliffs of rocks and sand, all beautifully colored, in every shade of red and yellow, by the deposits of sulphur which had acc.u.mulated upon them from the fumes of the volcano. The floor of the crater was black as jet, being covered by the molten lava, which had gradually spread over it. The surface of this lava lay in wave-like corrugations, like the hide of a rhinoceros, showing that it was or had been semi-fluid. In the centre rose a great, black, rounded cone, like the cupola of an immense blast furnace. This cone was about fifty feet high, and there was an opening at the top eight or ten feet in diameter, which glowed with a furious heat, and emitted quietly, but continually, a red-hot breath of sulphurous vapor.

After remaining thus quiet for a few moments, suddenly it would give a gasp, and immediately afterwards there would burst forth a thundering explosion, which seemed to come up from a great depth below, and threw into the air a shower of stones and sc.r.a.ps of molten lava, which, after ascending to a great height, came down again, and fell, with a dripping sound, upon and around the cone. Similar explosions occurred at intervals of a few minutes, all the time that the party remained.

Rosie was at first very much afraid of these explosions, and she wished to go back. Mr. George himself was also afraid at first to stand very near the edge of the crater; but it was not on account of the explosions, but for fear that the cliff might cave in. Indeed, the cliffs all around were cracked off, and in some places leaning over, apparently ready to fall; and even at the spot where the spectators stood looking into the crater, there was a fissure running along parallel to the cliff, some feet behind them. At first Mr. George was afraid to step over this crack.

"How do they know," said he to himself, "but that the whole ma.s.s will fall and carry them all down into the gulf below?"

He found, however, after waiting a little while, that it did not fall, and there were besides other ma.s.ses a little farther along, as seen in the engraving, which had become separated entirely from the cliff behind them, leaving a chasm open two or three feet wide; and yet they did not fall. So Mr. George gradually acquired more confidence, and at length went cautiously forward, and looked over the brink.

Rosie, however, hung back. She was alarmed to see Rollo and Josie go so near.

"Come back, Josie," said she; "come back. You _must not_ go so near."

So Mr. George called the boys back, and they obeyed.

The walls of this crater were on every side almost perpendicular. As the central part had gradually sunk, the sides had caved off and fallen in, and then afterwards the lava that had been thrown up had spread over the floor, and covered it with a bed of a half-fluid looking substance, that was as black as pitch, and which, though it was really now pretty hard, looked as if a stone thrown down upon it would sink immediately into it, out of sight.

The crater seemed to be four or five hundred feet across, and the walls of it were eighty or a hundred feet high.

After Mr. George and the children had been standing upon the brink of this abyss some time, watching the explosions, the guide who had come up with them from the Hermitage beckoned to Mr. George, and saying something at the same time in Italian, made signs as if he wished the party to go with him to some other place.

"Come, boys," said Mr. George; "he wants us to go with him."

"Where does he want us to go?" asked Rollo.

"I don't know," said Mr. George. "I cannot understand what he says; but let us go and see."

So the whole party followed the guide, Mr. George leading Rosie by the hand. The guide conducted them along a narrow path through the sand, which led away from the crater behind a hill which formed one of the sides of it at a place where it was so steep below the path down the mountain side, that Rosie was almost afraid to go. Mr. George, however, held her firmly by the hand, and he charged Rollo and Josie to follow very carefully. After going on in this way for some distance, they came to another crater very similar to the first, only the sides of it, instead of being formed, like the first, of perpendicular cliffs, consisted of steep, sloping banks of volcanic sand and gravel. There was, however, the same pitchy bed of lava spread out all over the bottom of it below, and in the centre a black cone thirty feet high, with a fiery furnace mouth at the top, glowing with heat, and throwing out continually the same thundering puffs of steam, and projecting the same ma.s.ses of melted lava and hot stones into the air.

"Ah, here is another crater!" said Mr. George.

"Yes," said Rollo; "only it is smaller than the first. I like the first the best."

While they were standing on the narrow ridge which formed the brink of the crater, looking down, their guide by their side, another guide came by, conducting two young men; and they, instead of stopping on the brink, as Mr. George and his party had done, began at once to go down.

There was a sort of track in the sand down the slope, and in this track the young men, half walking, half sliding, descended.

"Why, uncle George!" exclaimed Rollo, "they are going down into the crater. Let Josie and me go too."