A space capsule travels very fast. It travels so fast that it can go all the way across the country from one ocean to the other while you are eating your breakfast. When a space capsule is going around the Earth, at this great speed-perhaps at 20,000 miles an hour-it takes fast thinking to steer it exactly where it should go. People can’t think that fast.
By the time you could think,”Now I’ll turn the capsule,” you would already be past the turning place! That is why one of the most important members of a space team is a machine called the computer. The computer stays down on the ground, and as soon as a rocket fires, the computer starts working. It gets messages from the capsule every second. The computer knows exactly where the capsule is all the time.
If the capsule should go off its course, the computer can figure out what should be done to get the capsule back where it belongs. An instant message a rocket fire to steer the capsule back to where it ought to be. With the computer figuring things out, second by second the capsule can circle the Earth many times and then splash down safely in the ocean very close to the ship that will pick up the astronaut and capsule.
It might sound as if the computer were kept very busy, but for a computer it’s not busy at all.Some of today’s computers can figure out over a million things every second! Sounds like a good machine to have on your team, doesn’t it? And wouldn’t it be handy to have a pocket computer at school to do your arithmetic problems? Even though the computer can work out problems so fast, it doesn’t really think. Men figure things out much more slowly, but men figured out how to make computers!
This traffic light is a signal. it says something quickly and clearly for you. It tells you when you may cross the street safely and when you must wait for cars to go by. This smoke is a signal too. It was a signal used by the American Indians long ago.
To make their signal the Indians first gathered up a pile of sticks and wood and set on fire. They usually used damp wood because it burned more slowly and made a heavier smoke. After the wood was smoking, they held a blanket or large animal skin over the smoking wood. If they pulled the blanket off quickly, they could make a small puff of smoke. If they held the blanket down a longer time, they could make a large black puff of smoke.
Smoke signals sent news and messages to people far away. The signal meant different things to different Indian tribes. To one tribe these six puffs of smoke might mean,”Come on, the hunting is good here.” To another tribe it might mean,” Help! Our enemies are coming!”
At night when it was too dark to see smoke, the Indians made big bonfires on high ground. Then they used fire instead of smoke to make their signals. Sometimes they made fire signals with burning arrows. When the flaming arrows told good news, the rest of the tribe must have been happy to see them.
Shug-chug-chug-chug.Shug-chug-chug-chug.The battleship Monitor is steaming straight for the battleship Virginia. The sailors are shoving a shell into the Monitor’s forward cannon. Clank! They’ve locked the gun and …varoom! A puff of smoke. Splash! The shell hits the water. It misses its target. The cannon keeps shooting. People watching from the shore hold their hands over their ears, waiting for each blast. When it comes, some of the the ladies scream. Bavoom!Bavoom!Bavoom! Small children sitting on their father’s shoulders squeal at each boom and flash.
Finally a shell from the Monitor’s cannon hits the Virginia. But wait a minute-it bounces off the iron side without making a hole! “Yay!” the men on the Virginia are cheering. Now the wooden battleship Minnesota moves in, firing its guns at the Virginia. Oh! The Ironclad Virginia is turning its gun on the Minnesota. Boom! Va-Room! The wooden ship may not be so lucky. Crash! The Minnesota’s on fire! The flames are crawling up the Minnesota’s mast. You can see them reflected in the water. It looks as if the water is on fire..Boom-bavoom!Boom!Boom! the battle has been going on for hours. Splash!Splash!Boom!Boom!
The Monitor and the Virginia pound each other with their cannon shells. Sometimes they are half a mile apart-sometimes they are nearly close enough to touch. Boom-gadoom-aroom! Neither ship can sink the other. The Virginia is the first to stop the fighting and steam away. It was more than 100 years ago, on March 9,1862-the day when the first iron ships that ever built fought this famous battle.
The battle between the Virginia and the Monitor happened during the American Civil War. (The Virginia was once called the Merrimack, but this was before it was made into an iron ship.) After the historic fight, most of the battleships that were built anywhere in the world were made of iron or steel-not wood-because this battle proved that metal ships could not easily be sunk, even with big guns!