TELEGRAPHING WITHOUT WIRES 



281 



REFERENCES FOR FURTHER STUDY 

 Texts 



Caldwell and Curtis, Science for Today, Unit 9 



Clement, Collister, and Thurston, Our Surroundings, Chap. 17 



(part) 

 Hunter and Whitman, Science in Our World of Progress, 



Unit 10 



Lake, Harley, and Welton, Exploring the World of Science, 

 Chap. 25 



FIG. 460. HOW THE CRYSTAL WORKS 



Pieper and Beauchamp, Everyday Problems in Science, Unit 

 16 



Powers, Neuner, and Bruner, Man's Control of His Environ- 

 ment, Chap. 23 



Skilling, Tours through the World of Science, Tours 11 and 

 12 



Van Buskirk and Smith, The Science of Everyday Life, Chap. 

 18 



Webb and Beauchamp, Science by Observation and Experi- 

 ment, Unit 2 



Wood and Carpenter, Our Environment: How We Use and 



Control It, Topic 12 

 Special references 



Meister, Magnetism and Electricity 



Morgan, The Boy Electrician 



Seaver, The American Boy's Book of Electricity 



Mills, The Letters of a Radio-Engineer to His Son 



Kendall and Koehler, Radio Simplified 



Schubert, The Electric Word 



Darrow, Masters of Science and Invention 



WHAT YOU SHOULD AIM TO ACQUIRE FROM 

 THIS STUDY 



1. A knowledge of what wireless waves are. 



2. An understanding of how wireless messages are 

 sent and received. 



3. Something of the history of wireless. 



4. An attitude toward the importance of wireless as 

 an agency of communication and international un- 

 derstanding. 



TEST OF MASTERY OF THE TOPIC 



In your notebook complete the statements, answer the 

 questions and comply with the instructions. 



1. discovered electric waves. 



2. first experimented with wireless. 



3. Wireless waves are carried from the sending aerial 

 to the receiving aerial by . 



4. The frequency of an ether wave is its rate of 



-mrv 



-rrm- 



FIG. 461 



5. The wave length of a wireless wave is the distance 

 from to 



6. In your notebook connect by a pencil line the parts 

 of a simple wireless sending set as shown in Figure 461. 

 The pencil line represents the wire. 



7. What does the spark coil do? 



8. What parts are included in the primary circuit of 

 the spark coil? 



9. What parts are included in the secondary circuit 

 of the spark coil ? 



10. The voltage in the is greater than that in the 



circuit. 



11. An current wave is sent out by the sending set. 



12. Explain what principle is used when a current is set 



OTJ> 



-CEED- 



^ ite 



FIG. 462 



