So a living city was buried in a few hours. Wooded hills and green fields lay covered under great ash heaps. Ever since that terrible eruption Vesuvius has been restless. Sometimes she has been quiet for a hundred years or more and men have almost forgotten that she ever thundered and spouted and buried cities. But all at once she would move again. She would shoot steam and ashes into the sky. At night fire would leap out of her top. A few times she sent out dust and lava and destroyed houses and fields. A man who lived five hundred years after Pompeii was destroyed described Vesuvius as she was in his time. He said:

"This mountain is steep and thick with woods below. Above, it is very craggy and wild. At the top is a deep cave. It seems to reach the bottom of the mountain. If you peep in you can see fire. But this ordinarily keeps in and does not trouble the people. But sometimes the mountain bellows like an ox. Soon after it casts out huge masses of cinders. If these catch a man, he hath no way to save his life. If they fall upon houses, the roofs are crushed by the weight. If the wind blow stiff, the ashes rise out of sight and are carried to far countries. But this bellowing comes only every hundred years or thereabout. And the air around the mountain is pure. None is more healthy. Physicians send thither sick men to get well."

The ashes that had covered Pompeii changed to rich soil. Green vines and shrubs and trees sprang up and covered it, and flowers made it gay. Therefore people said to themselves:

"After all, she is a good old mountain. There will never be another eruption while we are alive."

So villages grew up around her feet. Farmers came and built little houses and planted crops and were happy working the fertile soil. They did not dream that they were living above a buried city, that the roots of their vines sucked water from an old Roman house, that buried statues lay gazing up toward them as they worked.

About three hundred years ago came another terrible eruption. Again there were earthquakes. Again the mountain bellowed. Again black clouds turned day into night. Lightning flashed from cloud to cloud. Tempests of hot rain fell. The sea rushed back and forth on the shore. The whole top of the mountain was blown out or sank into the melting pot. Seven rivers of red-hot lava poured down the slopes. They flowed for five miles and fell into the sea. On the way they set fire to forests and covered five little villages. Thousands of people were killed.

Since that time Vesuvius has been very active. Almost every year there have been eruptions with thunder and earthquakes and showers and lava. A few of these have done much damage. [Footnote: In this year, 1922, Vesuvius has been very active for the first time since 1906. It has been causing considerable alarm in Naples. A new cone, 230 feet high, has developed.—Ed.] And even on her calmest days a cloud has always hung above the mountain top. Sometimes it has been thin and white—a cloud of steam. Sometimes it has been black and curling—a cloud of dust.

Vesuvius is a dangerous thing, but very beautiful. It stands tall and pointed and graceful against a lovely sky. Its little cloud waves from it like a plume. At night the mountain is swallowed by the dark. But the red rivers down its slopes glare in the sky. It is beautiful and terrible like a tiger. Thousands of people have loved it. They have climbed it and looked down its crater. It is like looking into the heart of the earth. One of these travelers wrote of his visit in 1793. He said:

"For many days Vesuvius has been in action. I have watched it from Naples. It is wonderfully beautiful and always changing. On one day huge clouds poured out of the top. They hung in the sky far above, white as snow. Suddenly a cloud of smoke rushed out of another mouth. It was as black as ink. The black column rose tall and curling beside the snowy clouds. That was a picture in black and white. But at another time I saw one in bright colors.

"On a certain night there were towers and curls and waves and spires of flames leaping from the top of the mountain. Millions of red-hot stones were shot into the sky. They sailed upward for hundreds of feet, then curved and fell like skyrockets. I looked through my telescope and saw liquid lava boiling and bubbling over the crater's edge. I could see it splash upon the rocks and glide slowly down the sides of the cone. The whole top of the mountain was red with melted rock. And above it waved the changing flames of red, orange, yellow, blue.

"On another night, as I was getting into bed, I felt an earthquake. I looked out of my window toward Vesuvius. All the top was glowing with red-hot matter. A terrible roaring came from the mountain. In an instant fire shot high into the air. The red column curved and showered the whole cone. In half a minute came another earthquake shock. My doors and windows rattled. Things were shaken from my table to the floor. Then came the thunder of an explosion from the mountain and another shower of fire. After a few seconds there were noises like the trampling of horses' hoofs. It was, of course, the noise of the shot-out stones falling upon the rocks of the mountainsides eight miles away.

"I decided to ascend the volcano and see the crater from which all these interesting things came. A few friends went with me. For most of the way we traveled on horses. After two or three hours we reached the bottom of the cone of rocks and ashes. From there we had to go on foot. We went over to the river of red-hot lava. We planned to walk up along its edge. But the hot rock was smoking, and the wind blew the smoke into our faces. A thick mist of fine ashes from the crater almost suffocated us. Sulphur fumes blew toward us and choked us. I said,

"'We must cross the stream of lava. On the other side the wind will not trouble us.'

"'Cross that melted rock?' my friends cried out. 'We should sink into it and be burned alive.'

"But as we stood talking great stones were thrown out of the volcano. They rolled down the mountainside close to us. If they had struck us it would have been death. There was only one way to save ourselves. I covered my face with my hat and rushed across the stream of lava. The melted rock was so thick and heavy that I did not sink in. I only burned my boots and scorched my hands. My friends followed me. On that side we were safe. We climbed for half an hour. Then we came to the head of our red river. It did not flow over the edge of the crater. Many feet down from the top it had torn a hole through the cone. I shall never forget the sight as long as I live. There was a vast arch in the black rock. From this arch rushed a clear torrent of lava. It flowed smoothly like honey. It glowed with all the splendor of the sun. It looked thin like golden water.

"'I could stir it with a stick,' said one of my friends.

"'I doubt it,' I said. 'See how slowly it flows. It must be very thick and heavy.'

"To test it we threw pebbles into it. They did not sink, but floated on like corks. We rolled in heavier stones of seventy or eighty pounds. They only made shallow dents in the stream and floated down with the current. A great rock of three hundred pounds lay near. I raised it upon end and let it fall into the lava. Very slowly it sank and disappeared.

"As the stream flowed on it spread out wider over the mountain. Farther down the slope it grew darker and harder. It started from the arch like melted gold. Then it changed to orange, to bright red, to dark red, to brown, as it cooled. At the lower end it was black and hard and broken like cinders.

"We climbed a little higher above the arch. There was a kind of chimney in the rock. Smoke and stream were coming out of it. I went close. The fumes of sulphur choked me. I reached out and picked some lumps of pure sulphur from the edge of the rock. For one moment the smoke ceased. I held my breath and looked down the hole. I saw the glare of red-hot lava flowing beneath. The mountain was a pot, full of boiling rock."

Another man writes of a visit in 1868, a quieter year.

"At first we climbed gentle slopes through vineyards and fields and villages. Sometimes we came suddenly upon a black line in a green meadow. A few years before it had flowed down red-hot. Further up we reached large stretches of rock. Here wild vines and lupines were growing in patches where the lava had decayed into soil. Then came bare slopes with dark hollow and sharp ridges. We walked on old stiff lava-streams. Sometimes we had to plod through piles of coarse, porous cinders. Sometimes we climbed over tangled, lumpy beds of twisted, shiny rock. Sometimes we looked into dark arched tunnels. Red streams had once flowed out of them. A few times we passed near fresh cracks in the mountain. Here steam puffed out.

"At last we reached a broad, hot piece of ground. Here were smoking holes. The night before I had looked at them with a telescope from the foot of the mountain. I had seen red rivers flowing from them. Now they were empty. Last night's lava lay on the slope, cooled and black. I was standing on it. My feet grew hot. I had to keep moving. The air I breathed was warm and smelled like that of an iron foundry. I pushed my pole into a crack in the rock. The wood caught fire. I was standing on a thin crust. What was below? I broke out a piece of the hard lava. A red spot glared up at me. Under the crust red-hot lava was still flowing. I knew that it would be several years before it would be perfectly cool."

So for three centuries people have watched Vesuvius at work. But she is much older than that—thousands of years older—older than any city or country or people in the world. In all that time she has poured out millions of tons of matter—lava, huge glassy boulders, little pebbles of pumice stone, long shining hairs, fine dust or ashes. All these things are different forms of melted rock. Sometimes the steam blows the liquid into fine dust; sometimes it breaks it into little pieces and fills them with bubbles. At another time the steam is not so strong and only pushes the stuff out gently over the crater's edge. Many different minerals are found in these rocks—iron, copper, lead, mica, zinc, sulphur. Some pieces are beautiful in color—blue, green, red, yellow. Precious stones have sometimes been found—garnets, topaz, quartz, tourmaline, lapis lazuli. But most of the stone is dull black or brown or gray.

All this heavy matter drops close to the mountain. And on calm days the ashes, also, fall near at home. Indeed, the volcano has built up its own mountain. But a heavy wind often carries the fine dust for hundreds of miles. Once it was blown as far as Constantinople and it darkened the sun and frightened people there. Some of the ashes fall into the sea. For years the currents carry them about from shore to shore. At last they settle to the bottom and make clay or sand or mud. The material lies there for thousands of years and is hard packed into a soft fine grained rock, called tufa. The city of Naples to-day is built of such stone that once lay under the sea. An earthquake long ago lifted the ocean bottom and turned it into dry land. Now men live upon it and cut streets in it and grow crops on it.

So for many miles about, Vesuvius has been making earth. Her ashes lie hundreds of feet deep. Men dig wells and still find only material that has been thrown out of the volcano. When this matter grows old and lies under the sun and rain it turns to good soil. The acids of water and air and plants eat into it. Rain wears it away. Plant roots crack the rocks open. The top layer becomes powdered and rotted and mixed with vegetable loam and is fertile soil. So the country all around the volcano is a rich garden. Tomatoes, melons, grapes, olives, figs, cover the land.

But Vesuvius alone has not made all this ground. She is in a nest of volcanoes. They have all been at work like her, spouting ashes and pumice and rocks and lava. Ten miles away is a wide stretch of country where there are more than a dozen old craters. Twenty miles out in the blue bay a volcano stands up out of the water. A hundred miles south is a group of small volcanic islands. They have hot springs. One has a volcano that spouts every five or six minutes. At night it is like a lighthouse for sailors. One of these Islands is only two thousand years old. The men of Pompeii saw it pushed up out of the sea during an earthquake. A little farther south is Mt. Aetna in Sicily. It is a greater mountain than Vesuvius and has done more work than she has done. So all the southern part of Italy seems to be the home of volcanoes and earthquakes.

There are many other such places scattered over the world—Iceland, Mexico, South America, Japan, the Sandwich Islands. Here the same terrible play is going on—thunder, clouds, falling ashes, scalding rain, flowing lava. The earth is being turned inside out, and men are learning what she is made of.