A story I made up for my son tonight:

A long time ago in a land far, far away there were dragons. The land was called China and the people there feared and respected the dragons of the air, the land, the sea, and the fire.
When the people were good and took good care of the land, the sea, the air, and their fires, the dragons were kind and slept most of the time. But when the people were bad, and destroyed the land, put their garbage in the sea, polluted the air, and fought with their fires (instead of cooking and making good food and keeping warm), then the dragons were mad and would warn the people to be good.
Dragons in the air would flap their wings and bring terrible storms, dragons of the sea made big belly-flops and bring waves and floods to wash away the towns, dragons of the fire would huff and puff and make volcanoes explode, and dragons of the land would whip their tails back and forth against their homes in the earth – causing great earthquakes.
The people knew they could not stop the dragons except by taking care of the earth and respecting the dragons, who would just as well wipe all the people out to save the earth if they had to. So the people tried to be good.
And one day, a very smart man named Zhang Heng invented something to keep the people safe. He remembered when he was a little boy, that his Nai Nai (grandmother) told him that the lizards and frogs were cousins of the dragons and would always be the first to know if an earthquake was going to happen. If that was going to happen, the lizards and the frogs would all stop laughing and singing and go find a place to hide. Now Zhang Heng was not so foolish to think he could stop the dragons, and he knew that not everybody could pay attention to the frogs (like the people in the mountains or the city) but he knew he could help the people so not so many died or got hurt in the earthquakes.
So he made an invention called the “dragon detector”.
He took a big cookie jar and turned it upside down. Then he put a pendulum inside (you know, like the long swinging thing you see on big old fashioned clocks). The on the outside of the cookie jar he decorated it with little dragons all around it, like they were crawling down the sides. In the mouth of each dragon was a marble, and on the floor around the jar were little toy frogs, mouths open to catch the marbles.
Zhang Heng knew that if the dragons of the earth started whipping their tails back and forth, the pendulum would swing inside the cookie jar and tap the inside – jiggling the dragon on that side. The dragon would drop his marble – right into the mouth of the frog! And the frog’s mouth would close – just like the real frogs!

it looked kinda like this
Not only that, but you could tell what direction the earthquake was coming by looking at which frog had closed her mouth! That way, you knew which way to run in order to be safe! Zhang Heng thought this was a great invention and took it to the Emperor to show him.
But the Emperor’s men laughed at Zhang Heng. “Cookie jars?” “Marbles?” “Toy frogs?” “How can you tell us about dragons by playing with toys?!? You don’t know what you’re doing and you’re acting like a baby playing with toys!”
But Zhang Heng knew what he was doing and knew that he was right, so he quietly set up his dragon detector outside the Emperor’s castle. Then he sat down and he waited, and sure enough, not too many days later the dragon on the North side dropped his marble into the mouth of his cousin the frog, and she closed her mouth up tight.
“Ha ha!” said the Emperor’s men, “That stupid toy is foolish and worthless! We feel no earthquake, yet your toy says their is one! You lose!”
But Zhang Heng knew what he was doing and he knew that he was right, so he quietly sat down and he waited.
And sure enough, later that day a boy just about your age came running into the Emperor’s castle, crying “Help! Help! An earthquake is knocking down our houses and our people need your help!”
“Come here my boy, ” said the Emperor, “and tell me where you are from and we will send help right away.”
“Longxi, my Emperor,” said the breathless boy, “a day’s run North of here!”
“North!” said the Emperor to his doctors and soldiers, “take your men North to Longxi and help the people there!”
Then the Emperor looked at Zhang Heng and he smiled.
“You!” he shouted at his men who had teased Zhang Heng, “Go…make…some…toys…”
And the Emperor and Zhang Heng were best friends forever, and they saved lots of people by knowing where to send help long before a runner could come and tell them where the earthquake was.
And that’s the story of the dragons and the earthquakes, and the first dragon detector.
From a long time ago, in a land far, far away – called China.
Where they say dragons still sleep to this day…..
(read part 2 – The Dragon Crystals here)