But suddenly there was an end to their isolation.

Prehistoric man was discovered.

A traveler from the unknown south-land who had dared to cross the turbulent sea and the forbidding mountain pa.s.ses had found his way to the wild people of Central Europe.

On his back he carried a pack.

When he had spread his wares before the gaping curiosity of the bewildered natives, their eyes beheld wonders of which their minds had never dared to dream.

They saw bronze hammers and axes and tools made of iron and helmets made of copper and beautiful ornaments consisting of a strangely colored substance which the foreign visitor called "gla.s.s."

And overnight the Age of Stone came to an end.

It was replaced by a new civilization which had discarded wooden and stone implements centuries before and had laid the foundations for that "Age of Metal" which has endured until our own day.

It is of this new civilization that I shall tell you in the rest of my book and if you do not mind, we shall leave the northern continent for a couple of thousand years and pay a visit to Egypt and to western Asia.

"But," you will say, "this is not fair. You promise to tell us about prehistoric man and then, just when the story is going to be interesting, you close the chapter and you jump to another part of the world and we must jump with you whether we like it or not."

I know. It does not seem the right thing to do.

Unfortunately, history is not at all like mathematics.

When you solve a sum you go from "a" to "b" and from "b" to "c" and from "c" to "d" and so on.

History on the other hand jumps from "a" to "z" and then back to "f" and next to "m" without any apparent respect for neatness and order.

There is a good reason for this.

History is not exactly a science.

It tells the story of the human race and most people, however much we may try to change their nature, refuse to behave with the regularity and the precision of the tables of multiplication.

No two men ever do precisely the same thing.

No two human brains ever reach exactly the same conclusion.

You will notice that for yourself when you grow up.

It was not different a few hundred centuries ago.

Prehistoric man, as I just told you, was on a fair way to progress.

He had managed to survive the ice and the snow and the wild animals and that in itself, was a great deal.

He had invented many useful things.

Suddenly, however, other people in a different part of the world entered the race.

They rushed forward at a terrible speed and within a very short s.p.a.ce of time they reached a height of civilization which had never before been seen upon our planet. Then they set forth to teach what they knew to the others who had been less intelligent than themselves.

Now that I have explained this to you, does it not seem just to give the Egyptians and the people of western Asia their full share of the chapters of this book?

THE EARLIEST SCHOOL OF THE HUMAN RACE

We are the children of a practical age.

We travel from place to place in our own little locomotives which we call automobiles.

When we wish to speak to a friend whose home is a thousand miles away, we say "h.e.l.lo" into a rubber tube and ask for a certain telephone number in Chicago.

At night when the room grows dark we push a b.u.t.ton and there is light.

If we happen to be cold we push another b.u.t.ton and the electric stove spreads its pleasant glow through our study.

On the other hand in summer when it is hot the same electric current will start a small artificial storm (an electric fan) which keeps us cool and comfortable.

We seem to be the masters of all the forces of nature and we make them work for us as if they were our very obedient slaves.

But do not forget one thing when you pride yourself upon our splendid achievements.

We have constructed the edifice of our modern civilization upon the fundament of wisdom that had been built at great pains by the people of the ancient world.

Do not be afraid of their strange names which you will meet upon every page of the coming chapters.

Babylonians and Egyptians and Chaldeans and Sumerians are all dead and gone, but they continue to influence our own lives in everything we do, in the letters we write, in the language we use, in the complicated mathematical problems which we must solve before we can build a bridge or a skysc.r.a.per.

And they deserve our grateful respect as long as our planet continues to race through the wide s.p.a.ce of the high heavens.

These ancient people of whom I shall now tell you lived in three definite spots.

Two of these were found along the banks of vast rivers.

The third was situated on the sh.o.r.es of the Mediterranean.

The oldest center of civilization developed in the valley of the Nile, in a country which was called Egypt.

The second was located in the fertile plains between two big rivers of western Asia, to which the ancients gave the name of Mesopotamia.

The third one which you will find along the sh.o.r.e of the Mediterranean, was inhabited by the Phoenicians, the earliest of all colonizers and by the Jews who bestowed upon the rest of the world the main principles of their moral laws.

This third center of civilization is known by its ancient Babylonian name of Suri, or as we p.r.o.nounce it, Syria.

The history of the people who lived in these regions covers more than five thousand years.

It is a very, very complicated story.