UNIT XII. HOW MAN COMMUNICATES 



Throughout the ages the advancement of civiliza- 

 tion has been vitally dependent upon progress in two 

 great human needs, transportation and communica- 

 tion. Each has developed from the crude methods of 

 the savage to its present state of complexity. A study 

 of the advancement of the art of communication is in- 

 teresting. Prehistoric man, so far as we know, de- 

 pended solely upon word of mouth delivered person- 

 ally or perhaps by messenger. The more civilized an- 

 cients of Egypt, Babylonia, Assyria, and other great 

 empires at the dawn of history developed forms of 

 writing. As knowledge increased, messages were 

 scratched in crude hieroglyphics upon wax and even 

 clay and then upon parchment, but the time of de- 

 livery of the message was always dependent upon 

 the speed of the messenger. 



The ancient Aztecs, and perhaps other races, had 

 their heliographs ; the American Indian used his 

 smoke signal ; the African savage, his tom-tom code ; 

 but these and other methods of the kind were merely 

 makeshifts for emergencies and unavailable for in- 

 dividual communication. The art of writing was de- 

 veloped several thousand years ago. Five centuries 

 ago, Gutenberg invented printing, but it is significant 

 of the extraordinary progress of our own times that 

 through all the development of civilization it was not 

 until the last century that man developed a depend- 

 able method of really rapid communication between 

 distant points. 



The advances made in communication during the 

 last century have been remarkable : first, the telegraph 

 by Morse, then the telephone by Bell, the wireless by 

 Marconi, and then in rapid succession the myriad in- 

 ventions including household radio receiving sets, pic- 



tures by wire, pictures by wireless, and now television 

 in its infancy. The subject of communication is so full 

 of possibilities and romance that everyone should 

 want to know more about it. 



When one stops to consider the tremendous im- 

 portance of communication in promoting international 

 good will and understanding, it becomes a topic of the 

 highest importance. We want you to learn the how 

 and why of communicating devices and also about the 

 men who have made possible this important agency 

 of human welfare. 



What do you know about communication? Answer 

 as many of the questions as you can. 



1. What sort of communication was common dur- 

 ing the Middle Ages? 



2. What discoveries made possible the invention 

 of the telegraph and telephone? 



3. What device that you have already studied about 

 is made use of in the telegraph ? 



4. Does sound travel through the wire in a tele- 

 phone system? Explain. 



5. What kind of electric current is used in the tele- 

 graph and telephone? 



6. Of what importance is static electricity in radio? 



7. Open a telephone receiver by carefully unscrew- 

 ing the earpiece. What things do you recognize that 

 you have studied about? 



8. Open the radio set at home and then turn it on. 

 What do you observe? Describe accurately the ap- 

 pearance of the bulb. 



9. What is an electric current? 



10. How are cells and batteries able to furnish elec- 

 tric current? 



TOPIC 1. EARLY FORMS OF COMMUNICATION 



SUGGESTED PROBLEMS AND QUESTIONS 

 What is the early history of communication? 



a. How did separated groups in ancient times 

 communicate? 



b. How did people communicate during the Mid- 

 dle Ages? 



c. What forms of communication were used by 

 the Indians? 



d. How did the early American settlers com- 

 municate? 



SUGGESTIONS AND HELPS FOR STUDY 



1. The nature of this topic is largely informational 

 and will therefore demand considerable reading and 

 study. 



2. You will find a great deal of your material for 

 this topic in history books and general references and 

 comparatively little in science textbooks. 



3. Some of the material for c and d will no doubt 

 come out of your own experience and past reading, 



4. Make a picture-graph of the development of 

 communication, giving dates in so far as you are 

 able. You may wish to do this on large paper to put 

 on the science room wall. 



READINGS WHICH WILL HELP ANSWER THE 

 PROBLEM QUESTIONS 



What is the early history of communication? Com- 

 munication is as old as the human race. One of the 

 things that has enabled man to develop from the 

 savage state to that of modern civilization has been 

 his ability to communicate with his fellow beings. 



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