23. Sketch and describe the action of a combined sneak-current and air-gap arrester, as widely used by Bell companies.
24. Describe the self-soldering heat-coil arrester.
25. What is the purpose of ribbon fuses?
26. What is a drainage coil?
REVIEW QUESTIONS
ON THE SUBJECT OF TELEPHONY
PAGES 317—386
1. What is a central office?
2. What are (a) subscriber's lines? (b) Trunk lines? (c) Toll lines?