Communication Technology: From Smoke Signals to Smartphones
Contents Keeping in Touch 4 Telegraph 6 Box Phone 8 Radio Waves 10 Dial Up 12 Computers 14 Cell Phone 16 Smartphone 18 Future Phones 20 Timeline 22 Glossary 23 Further Resources 24 Index 24
Keeping in Touch People have always talked to each other from far away But they did not always have telephones They used different ways to get in touch with each other Smoke Signals Native Americans used smoke signals They built a fire on a hill They waved a wet blanket over the fire in patterns The smoke rose in the air People far away could read the patterns it made 4
Semaphore Sailors used colored flags to signal to other ships The flags were waved in patterns The patterns made up words This is called semaphore Sealed Letters People sent sealed letters They dripped hot wax on the envelope They pressed their ring into the wax This sealed the letter Read on to learn about how people have kept in touch through the years 5
