The Strange Adventures of a Pebble

by Hallam Hawksworth

CHAPTER XI

(NOVEMBER)

It is a noble thing for men ... to make the face of a wall look infinite, and its edge against the sky like an horizon; or even if less than this be reached, it is still delightful to mark the play of passing light on its broad surface, and to see by how many artifices and gradations of tinting and shadow, time and storm will set their wild signatures upon it.

—Ruskin: The Seven Lamps of Architecture.

THE HANDWRITING ON THE WALLS

One of the most interesting things in this whole wonderful story of the life history of the world is how men were first able to read it at all. For we know they didn't find it written out in plain print as we have it now. Neither was it told in any one language so that getting hold of the thread of the story they could unravel it all, as other learned men did the picture writing of the Egyptians and the wedge-shaped marks on Assyrian bricks.

We know already how they learned that rivers open their own gateways through the mountains; how they know rocks are made over in the fairyland of change; how they know the ancient glaciers scattered the boulders over mountainside, valley, and field; how they know the mountains are children of the sea.

All this and more we have been reading in the written language of the rocks, but there are other things in this rock script that I have kept for this last but one of our pleasant talks, so that they might serve as a kind of summary and remembrance of all that has gone before.

A WALL THAT VULCAN BUILT

I've said it several times before, but I can't help saying it here again, how much more wonderful the ways of Nature are than was ever dreamed of even in the wonder tales of the Greeks! Take this great iron wall, for example—a wall of the iron rock called "lava"—and who would suppose that it was made by natural forces? It was driven in a molten state into a crack in overlying rock. After it cooled, the rock above and on either side of it, being of softer material, was worn away. This wall is near Spanish Peaks, Colorado. It is 100 feet high and some 30 feet wide. Colorado boys, on their vacations in that region, run along the top of it for miles.

I. The Mysteries in Marble Walls

Take a piece of marble for example, such as you see along the walls of our great modern buildings. There's a story for you! Why, if half the things it tells had just happened, or even just been discovered by some enterprising reporter, we should see pages and pages about it all in every newspaper in the land.

HOW MARBLE RETELLS THE WORLD HISTORY

In that piece of marble alone you have a pretty full review of the earth's history; of many of the most important things we have seen and heard about since we all started out together in [Chagter I]. It tells of strange life in ancient seas; of being buried deep in the earth under immense pressure, and where it could feel the intense heat of the rock at the centre, and of coming up again completely changed; transformed from the substance of a dead sea creature's shell to a crystallized stone beautifully colored and of many patterns; of the chemistry of the world underground and the laboratories in which its lovely coloring were made and blended; and solid rock threaded through rock with a skill that no worker in mosaic has ever equalled; drawn out and fixed in mere films of white, fading into the rich dark of the marble around them like white clouds shredded by the winds.

THE STRANGE STORIES THAT MARBLE TELLS

Those broader lines bending and turning, rising and falling, tell of the work of the giant forces that lift the mountains into place and of the great earthquakes that accompany mountain building. When those little quavering lines were being made, away down in the earth where the limestone changed to marble, mountains were slowly rising into the sky on the earth's surface far above. The quaverings in the marble are pictures, "line drawings" of the mountain story. And beside these lines that you can read so plainly there are others so small that you need a magnifying glass to see them; echoes, away down in the fairyland of the microscope, of the doings of the giants of Mountainland far above.

In following the lines of the earth's great walls of rock over a wide extent they are found waving sharply up and down in one section, rising and falling like ocean swells in another, in forward sloping folds in another, and sometimes even with folds doubling over, as if the great mountains which these folds made were trying to stand on their heads.

WHY LINES IN MARBLE REPEAT MOUNTAIN FORMS

All these rock folds which, with the help of the sculpturing of the elements, produce the infinite variety of beauty in mountain scenery are, speaking generally, repeated in the lines of the marble. But they are repeated only in miniature, because the rocks deep in the earth are under such pressure that while the rocks on the surface are free to rise in big and comparatively simple waves those beneath are doubled up into smaller and much more crumpled folds. Take several sheets of paper lying free on the table and press them from the ends. They will rise in simple arches as most mountains do. Now lay a book on these sheets and press from the ends again. You see they crumple up a great deal more; the larger wrinkles themselves doubling into smaller ones.

HOW MOTHER NATURE MAKES HER Z'S

These Z-shaped rock folds were made by the crumpling up of the crust as the centre, cooling, shrank away. They are to be seen near the east end of Ogden Canyon, Utah. The black lines were added to the photograph in the offices of Uncle Sam's big department of geology at Washington, to show clearly just where the rock runs.

You may often have noticed a banded effect in marble. My, what power it took to do that! Pressure we can't realize. Pressure from above so great that it made this marble spread; moulded it like clay in the hands of the potter; the same kind of force that flattened out the pebbles referred to in [Chagter V]. This is called "rock flow," and how plainly the marble shows the flowing movement. I always think what the weather people call "stratus" clouds, look as if they were made by long strokes of a painter's brush; and this marble has the very same flowing lines. Such cloud pictures in marble are made where deposits of other kinds of rock have been interlaid with the deposits of limestone which afterward changed to marble, and it is where these bands are folded or bent that we have set down for us the story of the mountain folds.

Those gossamer effects and the little white clouds spinning out and fading into the general mass of the marble, how delicate they are! Yet it took a force that made the earth quake to put them there. The more we know of the strange and fearful things that happen in times of earthquake the more we can read between these filmy lines. They tell of the sides of mountains tumbling down and spreading their valleys with a chaos of broken stone; making cliffs where there were peaks and peaks where there were cliffs; changing the course of rivers; shifting whole forests on the mountainside and replacing them with grim walls and bastions of barren stone—all in the twinkling of an eye!

THE EARTHQUAKES AND THE DELICATE FILMS

It is by the crushing movements that made the earthquake that rocks are broken into confusions of cracks such as you often see in a thick glass window that has been broken. Then into these cracks come dissolved minerals from other rocks and harden into stone. In the marble one set of veins often runs right through another as if they had been inlaid. Then there may be other veins that cross both of these—no end of criss-crossings. The different sets of veins usually differ also in color and in grain, and even have different kinds of mineral in them. With a good hand-glass you can see this difference in texture.

WHEN THE EARTHQUAKE TAKES ITS PEN IN HAND

These are, so to speak, the autographs of earthquakes—the records earthquakes themselves make on an instrument called the "seismograph," using a stylus, as the ancients did, as you will see by looking up "seismograph" in the dictionary or encyclopædia. After an earthquake starts it seems to stop for breath or for want of the right word—just like people; for you notice portions of the lines are almost straight. These were made when the earthquake was comparatively quiet. Then, when it got excited again—as in the second record from the top—the stylus fairly jumped up and down; and there where the waves are long and close together the shocks were particularly severe and followed each other rapidly.

II. How Vulcan Drove his Autograph into the Rocks

But there is another kind of handwriting on the walls that was made with such a vigorous stroke that it also made the earth shake. Of course we might expect Vulcan to write a rather vigorous hand—Vulcan, forger of thunderbolts for Jove. The ancients thought volcanoes belonged to the kingdom of Vulcan, so in scientific language everything connected with volcanic action comes under the head of "Vulcanism." These queer letters we are talking about are called "dikes." They are made of lava that was driven into cracks in the rocks and afterward cooled into rock that is as hard as iron. Lava is often largely made of iron.

MR. VULCAN'S FAMOUS CASTLE ON THE HUDSON

This is a part of Mr. Vulcan's famous castle on the Hudson known as the Palisades. Here the lava rock has formed into columns which make the mass look all the more like some old castle of the Middle Ages. The "windows" are where the softer spots in the rock have decayed away. This castle—come to think of it—really belongs to mediæval architecture, for it was built in the Middle Ages of earth's long history.

THIS IS THE HAND OF VULCAN, TOO

Were you ever down by the seashore in a storm? If so you remember how the ground under your feet shook when a great wave rushed into some narrow passage or crevice in the rocks, and was tossed high in the air in spray. Then just imagine molten lava, which is many times heavier than water, driven into a crack in a rock with the force of a cannon-ball. That's how it happened. That's how those dark strokes in the rock with their heavy shading were made.

This was done in the depths of the earth; not on the surface where you see these rocks now. They used to have piles of other rocks above them, but these in course of time have been weathered away. This is known, not only from the marks of the wearing but from the fact that these dikes, as well as the rock into which they have been driven, are crystallized, wholly or in part. Such crystallizing, as we know, takes place away down in the earth.

Dikes are very common. In some places you find the rocks fairly laced with them. The picture of the dikes in the granite shores at Marblehead also shows (in the horizontal plan) many "faults" or slips of the rock since the dike was made, and each slip probably gave rise to an earthquake. So you see there's the story of a terrible time written on those quiet old residents by the sea.

THE GIANT'S CAUSEWAY

Here is a still more striking example of the formation of columns in lava—the Giant's Causeway. Here are 40,000 columns, packed like the cells of a honeycomb, and they slope to the pavement in the foreground that gives the mass its name. That bees should make their little honey-jars in such regular form is wonderful enough, but think of lava shaping its own self into columns like that!

DID MR. VULCAN USE A STEAM PILE-DRIVER?

Just what power Mr. Vulcan used to drive the dikes is not known for sure, but I'll tell you how it is supposed to have been done. Remember that all rocks that are deep down in the earth contain water, shut up in their pores. Then remember how hot it is down there and how this heat would make steam right in the rocks. Then let the rock above be cracked by the movements of the earth crust, and this crack extend down to where these hot rocks are, the pressure, being released along that crack, the melted rock (lava) would rush up, as it does in connection with the eruptions of volcanoes, and the exploding steam would help drive it.

III. Ancient Weather Records Turned to Stone

So much for the literary remains of Mr. Vulcan. Now let's see how much we can make out of the handwriting of the waters and the winds on these walls of time.

What does the picture at the top of [page 245] look like? Rain-drops in the dust. And so you see they are; but the rain fell so long that the pits made in the dust have turned to stone. Think of the autograph of a rain-drop older than the Pharaohs; older than the pyramids these Pharaohs built to perpetuate their names.

And this is how such rain-drops immortalize themselves; this is the interpretation of their handwriting on the walls. Along the dry shore of an ancient sea when the tide was out, rain-drops fell on the sand and dust. Tides often come in with a rush, in wild waves driven by the wind, but when there is no wind and no waves rolling in from far distant storms the tide may overspread such delicate things as the imprint of rain-drops with a thin protecting film of mud. This was what happened to our little rain pits. Later tides overlaid them deeper from day to day, and in course of time both the layer containing the rain-drop prints and the overlying layers of sediment turned to stone. Often the heat of a summer sun will bake these rain-drop designs and this you see helps; it holds the impression until the tide can come in and spread its protecting film. Many imprints of rain-drops and of the feet of reptiles are found in the sandstone underlying the coal seams in eastern Pennsylvania, and they are always, I am told, covered with a fine powdery material, which was once the slime and mud of the tide. Such rain marks are often found also in slate. Wouldn't you like to have a slate with one of these rain-drop autographs on it?

RAIN-DROP AUTOGRAPHS OLDER THAN THE PHARAOHS

Here, by the way, is a very important thing these rain-drops tell. Says Professor Shaler:

"They tell us that the ordinary machinery of the atmosphere was operating in those days very much as it is to-day, and that the climate was much the same."[55]

[55] This quotation is from Doctor Shaler's "Nature and Man in America," a book you should read, as you should all of Doctor Shaler's books. No one has observed so many interesting things in the field of geology and few have written about them so simply or reasoned about them so well.

So, he argues, the great Ice Age couldn't have been due to change of climate, but to the other things that we read about in [Chagter II]. For they even know in what ages different records of rain-drops were made because they are found in rocks laid down in different periods; and one of the periods in which they are found was that in which the North Pole ice and its neighbors came down and made us those long visits.

STORY OF A STROLL IN THE RAIN

Another story found in museums is written in slate—not by a rain-drop but by a living creature. The slate shows the track of a reptile with feet like a bird. Evidently he was strolling along in the rain; for there you see the marks of the rain-drops right among the marks of his feet, and in the footprints themselves. Being a reptile who spent much of his time in or near the water he no doubt enjoyed these little pats of the rain-drops as he went along.

BUT THIS STROLL WAS TAKEN IN THE SUN

In another of these museum specimens we see written out just as plainly the story of a stroll in the sun. There are the imprints of Mr. Reptile's feet, and there are the sun-cracks in the mud showing that the sun was shining—or at least that it had been shining for several days or weeks, for it takes a little time to make sun-cracks in mud. This story, we might suppose, was written so that it could be read by the blind; the cracks, as well as the footprints, are brought out in raised lettering. Sun-cracked mud, after a long dry "spell," will bake so that the cracks will not be washed out by the returning tide but instead be filled by other material, and this material will go on building up to a certain extent; so making those ridges.

"THEN THERE CAME A LONG DRY SPELL"

This shows how the cracks in dried-up mud are preserved in stone. The process is the same as in the case of the stone imprints of rain-drops, the imprints being protected by successive deposits of mud by quiet tides, and afterward turning to stone.

THE STONE AUTOGRAPHS OF GENTLE BREEZES

On still other stones you will find written the story of gentle breezes that stirred the water and made ripples on long-buried shores. First the breezes rippled the shallow waters near the shore. Then the waters rippled the sand, and the sediments of the tide preserved these ripple marks as they did the rain-drops and the footprints.

But the wind alone, without the help of water ripples, can write its name in the sands of time. And when you get to know the handwriting of wind and wave you will not mistake the one for the other. You are likely to find wind ripples on any big heap of sand. Have a good look at them and then go down to shallow water on a sandy shore and compare the two kinds. That's the way the great men of science do; they notice every little thing.

From Norton's "Elements of Geology." By permission of Ginn and Company

THE STORY OF BIG ROUND TOP AND LITTLE ROUND TOP

One story of Big Round Top and Little Round Top your history tells, but long before the battle of Gettysburg these two mountains had age-long battles of their own with the winds, the rains, and the frosts, and in these battles lost their peaks and their sharp outlines of jagged rock, and became rounded down to the forms we see before us. Those rocks in the field were probably broken off in these battles, as the rocks of high mountains are to-day, and carried down by roaring torrents.

WEATHER RECORDS ON THE MOUNTAIN WALLS

From a scientific standpoint little things may be just as big as big things. For example, in this matter of old weather records these rain-drops and ripple stones are just as interesting as other weather records written large on mountain walls; such as those which tell that what is now the Dead Sea was once part of a much larger sea that wasn't dead at all. You may never get to read these records on the mountain walls of Palestine, for they are a long way off, but here in our own country we have a similar story told on mountain walls in the region of another dead sea—the Great Salt Lake of Utah. From Salt Lake City you can see on the mountain surrounding the desert of the Great Basin the marks of old shore lines; where the waves cut into the rock. These marks show that this Basin once held two great lakes, and the one in the eastern portion dried up into what is now Great Salt Lake.

WEATHER RECORDS ON THE WALLS OF TIME

What is now the Great Salt Lake used to be a much greater lake that wasn't salt at all. That vast flight of steps up the mountainside shows how wide it spread. As the big lake dried up, and grew smaller and smaller and saltier and saltier, its shores were bounded successively by those wave-cut cliffs.

IV. Stories Written on the Pebbles

Sometimes when a geologist picks up a pebble and looks at it a moment he can hear the roar of mountain torrents and of lowland streams in flood. If the pebble is round it shows that it has been carried far and rolled about by streams. If it has pits in it this shows that its water journeys were rough, because such pits are made by knocking against other pebbles and sharp stones in the struggle and confusion of the rushing waters. You see these little dots are a kind of shorthand, for we pebbles are stenographers too!

THE PERCHED BOULDER IN BRONX PARK

This is one of the interesting things to be seen when you visit Bronx Park in New York City. Of course, you know how that old boulder got there, and how he drew those straight lines in the rock-bed beneath, but many visitors to the park do not.

HOW PEBBLES TELL OF THEIR TRAVELS

Other great stories in small space are told on glacial pebbles. Scientific men can often tell from the look of a pebble whether it was shaped by rivers, by the sea, by the sand blasts of desert winds, or by the glaciers. Not only that, but, if it is a glaciated pebble, on what part of the glacier it was carried; whether in the middle of its back, or on the sides, like the passengers in an Irish jaunting-car; or whether it rode underneath, like a tramp stealing a ride on the bumpers. The stones in the middle of the glacier's back naturally keep their sharp edges longer than stones on the side, ground as the side stones are by the moving ice mass against the mountain walls. And the stones on both top and sides would lose less of their edges than the stones underneath the ice.

From Norton's "Elements of Geology." By permission of Ginn and Company

ONE PEBBLE IN ITS TIME PLAYS MANY PARTS

Here are pebbles faceted in different ways by glaciers. No. 1 has six facets. No. 4, originally a rounded river pebble, has been rubbed down to one flat face. Nos. 3 and 5 are battered little travellers faceted on one side only. Notice how No. 5 got his face scratched just as I did.

PEBBLE FACETED BY WIND-BLOWN SAND

You remember how the glaciers ground flat faces or facets on the pebbles, don't you? Here is another example of Nature's lapidary work, but here she has used wind and sand instead of ice.

V. A Greater Cæsar and His Commentaries

Well, there he is again, you see, Mr. Glacier of the Ice Age. He's always turning up, everywhere you go in earth history. As Shakespere's Mr. Cassius said of Mr. Julius Cæsar, "he bestrode the world." And, like the Roman Cæsar, this Cæsar wrote the story of his own exploits; but although a vastly greater conqueror than the famous Roman, he was even more modest. Cæsar and his Commentaries, our High School friend will tell you, nearly always refers to himself in the third person; but in his commentaries on his travels and exploits the Old Man of the Mountain didn't even use his own name. He left the editors of his manuscript to find out who he was.

HOW THE GREAT LAKES WERE TIPPED UP

One of the most striking things he did, of which he wrote the record on the walls, was to tip up the Great Lakes. You remember just how he made them. Well, it seems that as he started back home he tipped them up. Suppose you could pick up the vast stone bowls that hold these lakes and tip them toward the north as easily as you can tip a bowl of water, what would the water do? It would fall lower along the south shores of the lakes and rise along the northern shores, wouldn't it? Then suppose the lakes were kept tipped up in this way for ages, and summer wind storms and winter tempests dashed waves against their shores, what would happen? Stone walls rising above the shore would have terraces cut into them, and the line of these terraces would tilt toward the north. There are terraces just like that on rocks bordering the Great Lakes, and the explanation of their tilt is that the lakes themselves were tipped up, and that the Old Man of the Mountain did the tipping. The rock crust of the round earth bends under great weight like an arch. So when the enormous weight of the glaciers of the Ice Age was on a portion of the arch it bent down. Then, as the glaciers retreated, the weight of them was shifted northward all the time. Finally when the glaciers in the region of the lakes had melted quite away the arch slowly rose into place again and lifted the terraces above the water line as we see them to-day.

Throughout regions the glaciers visited you find rocks polished like mirrors; in other cases they are scratched, and in others deeply grooved.

SCENE ON THE COAST OF NORWAY BY A GLACIER

You know the fiords. You've met them in your geography. This is a fiord on the Norway coast. Notice how smooth the walls of the mountains are. They were trimmed down by the ice, which also plowed off their soil. We are here looking up what was once a river valley, but the glacier cut it down below sea level, and this is sea water. Notice in the openings of the mountains all the way up the valley where the tributaries of the ancient river flowed in then as now.

HOW THIS MR. CÆSAR IS TRANSLATED

No one scratch can be followed far. The composition is, like Cæsar's, in short sentences, whole episodes in a word: "Veni, vidi, vici." But a series of scratches all run in one general direction—north and south. To get at the meaning—just as in construing Cæsar—you must take the context; what goes before and after.

The sides of the valleys of the Alps from 1,000 to 2,000 feet above the surface of the glaciers of our own time are scratched and furrowed in the same way. Here we catch Mr. Glacier almost in the very act of writing.

THE HANDWRITING OF THE TWO CÆSARS

To do this writing, our Cæsar, like the Cæsar of the High School, used a stylus. Mr. Glacier's stylus, as we know, was made of stone held fast in his icy grip ([page 121]). And here is another curious resemblance between the manuscripts of Mr. G. Cæsar and Mr. J. Cæsar. They both wrote in straight lines. The reason Julius Cæsar and other Roman gentlemen wrote in letters made of straight lines was that they scratched these letters on tablets covered with wax, using a sharpened piece of iron or ivory. You can see it would be much easier with such writing tools and material to form letters in straight lines than to write in flowing, rounded and connected lines as we do so easily with a nice flexible pen on a smooth surface.

HOW THE OLD MEN CHANGED A "V" TO A "U"

Here is something else about the story of the Old Men of the Mountain that is a curious reminder of the Romans and their letters. The Romans had no letter U in their alphabet and so V had to do a double duty; it had to be a V and then when asked, had to take its place in line and pretend to be a U. For instance, a Roman who wanted to write the word "number" would do it in this way: "NVMERO." After a while, in the history of the growth of our alphabet, the V that was intended for U was rounded at the bottom.

Now, curiously enough, the writing of the Old Men of the Mountain has gone through the same process. River valleys in mountain regions, as elsewhere, are originally V-shaped, but where glaciers flowed down these valleys they not only made them wider but rounded out the bottoms so that they became U-shaped. Look at the valley in the Wind River range in Wyoming shown in the geologies. You notice the farther your eye goes up into the mountains the more V-shaped the valley becomes. Back toward antiquity, you see, when they had nothing but V!

THE HANDWRITING OF THE GLACIERS AND THE ROMANS

Here is an interesting relic of ancient days that will enable you to compare the chirography of the Old Men of the Mountain with that of the Romans. These are marks left by the masons on Roman walls. They show just what part each mason laid, so that if the wall proved defective the authorities would know who was responsible.

All quite striking, isn't it, this strange kind of writing on the walls of time? As if, among the ruins that are all there is left of the fallen Roman Empire, we should in some heap of dust and crumbled stone find one of the very tablets on which Cæsar wrote his commentaries and there engraved in Cæsar's own hand:

THIS STYLE IS CALLED FLUTING

Looks like moulding, doesn't it? This is a piece of rock, and it was carved in that way by the glaciers with their tools of embedded stone. The deeper grooves were made where the rock was softer or where the glacier's chisels were of a particularly hard quality, such as flint or granite.

"Cæsar, maximis bellis confectis, in hiberna exercitum deduxit."

Can you translate that for us? (This to the High School Boy.)

"As easy as anything," says he. "Cæsar, on completion of these great wars, led his army into winter quarters."

And that same phrase might serve in Mr. Glacier's Commentaries too. For the glaciers of the Ice Age, after their great work was done, also went into winter quarters; melting back to the present snow-line in our mountains and the regions of eternal ice around the pole.

HIDE AND SEEK IN THE LIBRARY

One of the most interesting stories of men's handwriting on the walls and how scholars, many centuries afterward, learned to read it, you will find in encyclopædias, histories, and other books under such headings as Egypt, Assyria, Rosetta Stone, and most of all under Hieroglyphics; a big word, but full of meat when once you've cracked the shell.

Among other things, you will find that if it hadn't been for the Egyptians and other clever people of the long ago we would not have had our written language to read at all; on walls or anywhere else!

If you had been an Egyptian, say 4,000 years ago, how many letters do you suppose you would have had to learn before you could have read well? About a thousand! But it wouldn't have been so hard as you think, for the Egyptian letters talked, so to speak. They told their own story much as did the picture words that told so much to the little Greeks. These Egyptian words, however—for they were words, or several words in one, rather than letters—were real pictures, and very good pictures, too. (See Chambers under "Hieroglyphics" for the little pictures.)

Some of them were very simple. It wasn't hard to learn.

But now suppose you were an Egyptian and you wanted to write a letter telling somebody how pleased you were about something—a nice new book an uncle had sent you, for instance—the proper picture-word to use would be a lady beating a tambourine. She is pleased—that's why she is beating the tambourine, just as a small boy claps his hands when he says, "Oh, goody, goody!" So this picture-word came to be used to express "joy" or "pleasure" over anything.

These are just some samples to show you what interesting things even such formidable words as "hieroglyphics" are when you make friends with them. But now, to get back to Nature's handwriting and the nature myths connected with it, what do you know about this Vulcan, who left so much of his manuscript in the rocks?

The ancients thought of him as a worker in metals. Don't you think they would have, been quite sure of it if they had known about the dikes and the palisades of the Hudson, and Fingal's cave, with their remarkable iron-like columns of cooled lava? But he was an artist in metals, too, and a mechanical engineer, it seems. Do you remember about those two statues of beautiful women that he made of pure gold, and how they walked about with him wherever he went? And the brazen-footed bulls of Ætes, that filled the air with their bellowings and from their nostrils blew flame and smoke?[56]

[56] I wonder if Vulcan could have been thinking of locomotives—what we sometimes call "iron horses"—when he made those bulls. Do you suppose?

The Greeks probably didn't know about such "art metal" work as the palisades—certainly they didn't know about the Hudson River or Fingal's Cave—but they had Vulcan (Hephæstus they called him) doing all sorts of other art-metal things. There was the famous shield he made for Achilles, for instance. Homer takes several pages just to tell about the different figures on it and what they meant.[57]

[57] The Iliad.

Why do you suppose a temple was erected on Mount Etna? (What kind of a mountain is it?)

Wouldn't it be strange if we could make hard coal out of soft? Vulcan does that sometimes with these dike strokes of his.[58]

[58] The International Encyclopedia.

The International will also tell you why dike rock is usually so solid and tough, and what the crystal people have to do with making it so.

The Britannica (28: 188) tells how, in the walls of volcanoes Vulcan wrote out the hint for making re-enforced concrete which is so important a feature of modern architectural engineering.

Look about on the rock-beds in the stone quarry and see if you can't find some of the writing of that Older Cæsar with his queer stone stylus. Probably the men in the quarry will have wondered how these scratches came there and you can tell them.

There is one style of Mr. Glacier's hand-work that even the dogs and the horses notice, and that is the "mirror rocks." Muir tells about them in his "Mountains of California."