6. Give the names of the different parts of a railway composite set and explain method of operating.
7. State the causes of the introduction of the telephone into the train dispatching field and explain the advantages it has over the telegraph for this work.
8. In transmitting orders for train dispatching, how are mistakes avoided?
9. Describe the Western Electric selector and explain its use.
10. In what way does the Gill selector differ from the Western Electric?
11. What special feature does the multiple coil selector possess?
12. What special arrangement is provided for the train dispatcher in noisy locations?
13. How can a man on a wrecking train get connection with the train dispatcher?
14. What is the usual limit in length of a telephone train dispatching circuit and what is the largest number of stations at present existing on such a circuit?
15. What is the voltage of the sending battery for a train dispatcher"s circuit and upon what is it dependent?
16. For what purpose is a repeater circuit used?
17. How is the noise caused by a high voltage battery absorbed so that the dispatcher may talk and signal simultaneously?
18. Draw a diagram showing the circuit arrangement for the dispatcher"s outfit of the Gill system.
19. Explain fully the purpose of the r.e.t.a.r.dation coil in connection with a waystation set.
20. In case of accident to a train wire between two stations, how can the connection be patched if the road is also equipped with a message circuit in addition to the train wire?
21. Why do some railroads have block wires in addition to train wires and message circuits?
22. If a waystation on a block wire is to be cut out for any length of time, by what method can the two adjacent blocks be connected, eliminating the station between?
23. What are some of the methods used for dispatching on electric railways where the traffic is not especially heavy?
24. On an electric road in case a car approaches a semaph.o.r.e set at "danger," what must the crew of the car do?