TREE PROTECTION 



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Figure 10. Today you talk over a wire; Tomorrow you'll see over one. On left is a section of 

 cable, containing 600 wires, such as now is used for long-distance calls and network radio pro- 

 grams. At right is a section of the new "coaxial" cable, over which you can "see" by television 

 as well as talk. It is only one-ninth as large as the other and contains two flexible copper tubes, 

 with a thick wire inside of each. Waves like those of radio will carry 240 conversations at once 

 through this cable, each at a different frequency. Other waves will carry television pictures over 

 the same channel. Copyright National Geographic Society. 



