The press is a great user both of the postal and telegraphic department. In the postal department the representatives can call for letters at any hour, provided their letters are enclosed in a distinctive-coloured envelope, such as bright red or orange. Of course this privilege has to be paid for. In the telegraph department the press can obtain their 'private wires' after six in the evening, as the wires are no longer required for commercial purposes. The plan adopted in sending the same message to every provincial town which has a daily journal is the following: all along the route the operators are advised of the fact, and whilst the message is only actually delivered at its final destination, the words are caught as they pass each town by means of the 'sounder.' By this ingenious arrangement, dozens of towns are placed in direct communication with the central office whence the message is despatched. To carry on our telegraphic arrangements three miles of shelves are needed, on which are deposited forty thousand batteries. THE POST-OFFICE ON WHEELS. The particular portion of the 'Post-office on Wheels' which we purpose describing is the Special Mail which leaves London from Euston Station daily. We have selected this mail, not only because all the duties appertaining to the Travelling Post-office are performed therein, but also because it is the most important mail in the United Kingdom, probably in the whole world. In the Special Mail, the post-office vehicles are forty-two feet in length, and one of thirty-two feet. There is a gangway communication between all the carriages, so that the officers on duty can pass from one to another throughout the entire length without going outside. All the carriages are lighted with gas. The pair-horse vans which convey the London bags for provincial towns come dashing into the station in rapid succession, and as there are only fifteen minutes before the train starts, no time is to be lost. The bags are quickly removed from the vans, the name of each being called out in the process, thus enabling an officer who stands near to tick them off on a printed list with which he is provided. They are then stowed away in the respective carriages in appointed places.