Upwards of 3,000,000 miles are run annually by Travelling Post Offices in this country. The largest number are run on the London and North-Western and Caledonian Railways, amounting in all to 1,800,000 miles. The London night mail is the heaviest mail in the course of the twenty-four hours. Day mails and mid-day mails are merely subsidiaries to the larger service. It has been said that “the principal mail train in the kingdom, perhaps in the whole world, is the Down Postal Express which leaves Euston every night at 8.30.” It consists entirely of postal vehicles, and carries thirty Post Office officials, the only representatives of the railway company being the driver, fireman, and guard. At Tamworth connection is made with the Midland Travelling Post Office going north and south and with the Lincoln sorting carriage. At Carlisle the Caledonian Railway takes on the running. The London officers are relieved here, and Glasgow and Edinburgh sorters take over the carriages journeying to these cities. At Perth the train is on the Highland Railway system, and has a direct run to Aberdeen. At most important points on the road it connects with cross-country routes. The Great Western Railway has a similar train which leaves Paddington at 9.5 P.M. and is due at Penzance at 6.45 A.M. The mail is divided for sorting purposes into five divisions, the fifth being known as the Cornwall Section. At Reading a large number of bags are exchanged for the South and Midlands. The London and South-Western Travelling Post Office is connected here with the Paddington mail. Travelling Post Offices are attached to the night trains on other lines from London, and these trains also carry passengers. At 9.13 P.M. there is a carriage from London Bridge for Brighton and south coast towns. The Great Eastern trains leaving Liverpool Street for Ipswich and Norwich at 8.50 P.M. and 10.7 P.M. have sorting carriages attached to them. The continental night mail leaves Cannon Street at 9.5 P.M., and is followed at 10 P.M. by the South-Eastern Travelling Post Office. There is also a night mail between Holborn Viaduct and Folkestone in connection with the Flushing route to the Continent.