treasures of Signor Petito himself… But how the deuce am I to do it? He is in the train which is going to pass under my nose."
At this point it is necessary to give a map:
Station ADCStation B
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It is unnecessary to give the names of the stations, for the demonstration is practically geometrical, and to geometry letters are more appropriate.
Let us go to station A. The signal-man of station A hears the ting! of the bell which announces that the express he is expecting has passed station B, and is on that section of the block-system which begins at station A and ends at station B. The express goes from B to A. It is on the line B A. That is clear. The signal at A announces the train by lowering its little red arm with a ting!
The signal-man at station A waits for the train, and waits for the train, and waits for the train! It ought to be there. It is a train which goes sixty miles an hour, and, if it is late, it goes seventy or eighty. The distance between station A and station B is at the most three miles and a furlong. Three minutes and a half is the longest an express
