18. The Policemen stationed at Tunnels and intermediate Stations are directed to be very particular in making the Signals according to the Regulations. (_See Signals._) 19. In all cases where Telegraphic communication is laid through a Tunnel, the Policeman at the entrance thereof is to sound the =Bell= on a Train going into the Tunnel, and the Policeman at the other extremity is to respond to the Signal on the Train emerging from it. 20. The Policeman stationed at the South entrance of the Primrose Tunnel is to sound the =Alarum= as soon as an Up Train enters the Tunnel, that the Camden Station may be made aware of the approach of a Train, and, if a Goods or Cattle Train, he is to turn it into the siding. Should it be a Passenger Train, the Policeman at Chalk Farm Bridge is to pass the Signal to the Euston Station. 21. When the Policeman at the South entrance of the Primrose Tunnel cannot distinguish the Signal at Chalk Farm Bridge, he is to show the =Green= Signal to every Engine passing towards Camden Station, and the Engineman is then to bring his Engine to a stand at the same Bridge unless signalled to proceed. 22. The Policeman in charge of the facing Points at the summit of the Incline at Camden is not to move them to allow an Engine to run into the siding, unless the Engineman motions with his hand. (See Rule 48, page 176.) 23. The duties of Pointsmen in charge of Switches are very simple, easily understood and remembered, and are at the same time not heavy, but they require great =care=, =attention=, and =watchfulness=, for any neglect may cause very serious accidents; Policemen are, therefore, warned always to be on the alert, and cautious in the discharge of their duty as Pointsmen. 24. The Pointsman is to be careful in keeping his Switches =clear= and well =oiled=: and whenever a Train has passed over, he is to see that no particle of coal or dirt has dropped within the Points, so as to prevent them from closing, and also that they are replaced in the =proper position=. He is also to try his Points before the passing through of a Train, that he may be thoroughly satisfied there is no impediment to their true working. 25. Where, from the peculiarity of the Line, it is necessary to employ facing Points, these precautions become =doubly= important. 26. Whenever, from the passage of a Train, the Points, Crossings, or Guide-rail receive injury or strain, or the rails themselves are =split= or =chipped=, the circumstance must immediately be reported. 27. In order to assist in discriminating Luggage Trains at night from Passenger Trains, the former carry a =Green= light on the Buffer-plank; but it must be understood that this is intended merely as an auxiliary signal, and is not to be =relied on= for turning a Train into a siding, which is only to be done when the Policeman on duty shall have =satisfied himself= as to the character of the Train. SECTION X.