As a further precaution during the hours of relaying, the _Green_ Signal is to be shown at Crick, and by the Policeman stationed at Hillmorton Ballast Pit, as notice to the Drivers in either direction to shut off the steam. On the approach of a Train to either entrance, the Policeman on duty is to sound the Telegraph Bell, whereupon the Policeman at the other end will respond by sounding his Bell; and immediately after telegraph “_Line clear_,” or “_Line blocked_,” as the case may be. If the answer be “_Line clear_,” the Train is to be allowed to enter the Tunnel, the Policeman at the entrance telegraphing back to the other end “_Train in_,” whereupon he will not again telegraph, or allow any Engine to enter the Tunnel, until he receives Telegraph Notice from the other end “_Train out_.” The same process and precaution is to be observed with every Train that may arrive, and no Signal is to be considered received and understood until responded to. Whichever end first rings the bell to announce the approach of a Train, that Train is to have the precedence, and a Train arriving at the other end is to be kept clear of the Crossing Points until the first announced Train has passed, when, after telegraphing “_Train out_,” and getting the response from the other end, the Policeman at that end will ring his bell as notice that he has a Train waiting to enter, which is to be allowed to proceed after passing the Signals as before described. Three Policemen are also to be stationed in the Tunnel, with Fog Signals and Hand Lamps, to signal the Trains as they pass through; and one additional at each entrance, to assist in the Signals and crossing the Trains. The Drivers are to be strictly enjoined to approach the Tunnel with caution, as a Train may be standing outside, and on passing through they are to be prepared to bring their Train to a stand, should it be necessary to stop unexpectedly. H. P. BRUYERES. LONDON AND NORTH-WESTERN RAILWAY. _Superintendent’s Office, Euston Station, 30th August, 1848._ RELAYING OF THE UP LINE BETWEEN BERKHAMPSTEAD AND TRING. The Engineer Department have notified that they are prepared to relay a portion of the Up Line, between the 27¾ and 30 Mile Posts, north of Berkhampstead Station. The plate-layers are to work at the undermentioned times, viz.:-- From 3.50 A.M. to 5.40 A.M. That is, after the passing of the 12.15 Night Mail Passenger Train from Birmingham, until the 2.0 A.M. Goods Train from Rugby becomes due. Again-- From 7.50 A.M. to 8.55 A.M.