И. А. Курбасова Е. И. Силантьева

Early Steps of Signalling
(1) You must have read that signals were not used on the early railways when only one locomotive was in use on a line. When the traffic increased, however, people demanded that some form of signalling should be adopted to assure safety.

(2) The first signals employed were railway "policemen". Their job was to provide a certain interval between the trains lest trains should collide. If the line ahead was occupied, the "policeman" stood with his feet apart and with an outstretched arm holding a red flag. Later on, the places where the "policeman" stood came to be known as stations and a red flag suggested the idea of red lights indicating "stop".

(3) As time went on, coloured discs and semaphores were adopted to act as signals. All of them, however, were manually-operated, and that made it necessary for the man on duty to walk a good deal to change their positions. Soon someone advised that the signals should be connect­ed by wires so that any number of them would be worked from one place.

(4) This control from a distance, or remote control, is sure to be a very valuable invention in the railway history for it enabled any required number of signals to be gov­erned from a single point.

13. Подготовьте сообщения на следующие темы.

1. The main stages in the development of railway sig­nalling.

2. Centralized Traffic Control. ' ..

3. The semi-automatic driving of trains.

14. Прочтите текст В без словаря и изложите его содержание по-английски, используя инструкцию, данную к упр. 14, Урок 15 (15 мин.).