Bruce E. Eckhart, age 9, of Fort Dodge, Iowa, for his question:

When was steam power discovered:

Boiling water, as we know, turns to steam    and the gaseous steam needs a lot snore room than the liquid water. It spreads out, pushing aside things that happen to be in its way. Naturally many people have been curious about the powerful strength of steam. Thousands of years ago, a few thoughtful people wondered how this steam power could be used. Many invented gadgets to tame it. But nobody made steam engines do use¬ful work until about 270 years ago.

Everybody knows that steam is hot and every young person learns that the steam from a boiling kettle causes serious burns. People discovered this thousands of years ago, right after they discovered how to boil water. No doubt they noticed that steam has pushing power right after they learned to put lids on their boiling kettles. This too was thousands of years ago. .Possibly several thinkers of ancient days tried to tame the power of steam and make it useful, but they did not succeed and we do not know who they were. The earliest experiment with steam power that did succeed happened over 2000 years ago.

The inventor's name was Hero and he lived in the Egyptian city of Alexandria. Hero left a detailed description of the machine he invented to tame the power of steam. Some say he actually made it, some say he only described it. In any case, his machine was designed to use the power of steam to spin a metal globe around and around. This was in 120 B.C. But though Hero's gadget used steam power, it did not do any really useful work. And for almost another 2000 years nobody succeeded in taming the power of steam to work for us.

The world was not ready to make this invention until the 16006. To make steam, we need an easy, foolproof way to boil a lot of water. We also need plenty of cheap fuel and a sturdy metal boiler, so strong that the expanding steam cannot burst it apart.

The time for a useful steam engine to be invented came in the 16006 and 1700s, when men began thinking about machines to do heavy work. They believed that this could be done  ¬and they went ahead and proved it. They invented one machine after another, and without stopping they went right on to make each one better. This exciting time in history is called the Industrial Revolution.

For ages, the miners of England had been toiling to drain water from their mines with back breaking hand pumps. At last, in 1698, a military engineer names Thomas Savery invented a pump driven by steam power to do the job. It worked and people called it the miner's friend. In 1705, a blacksmith names Thomas Newcomen invented a different type of steam pump that did the job better. In 1765, James Watt invented a still better steam pump that used only one fourth as much fuel. At last, in the 1700s, the world was ready to tame the power of steam and make it perform all sorts of different jobs.

James Watt started wondering about steam power when he was just a boy. He watched it make the lid bob on a boiling kettle. After his successful steam pump went to work in the mines, Watt designed steam engines to do many other jobs. He invented a steam engine to run a drop hammer and another to run a grain mill. In the 1800s, steam was used to pull things    and the steam locomotive huffed and puffed into the world.