The contract speed of the steam vessels that sail between Southampton and Alexandria is ten _knots_ an hour, exclusive of the stoppages allowed by the British Post Office, at Malta and Gibraltar. The time, therefore, occupied in the passage between Southampton and Alexandria is fourteen days, and as the vessels are timed to arrive at the latter port, at least one day in advance of the steamer _viâ_ Marseilles, the journey may be said to require fifteen days. As the mails conveyed by the steamers _viâ_ Marseilles only requires eight days, it follows, in order that the mails _viâ_ Southampton and _viâ_ Marseilles be carried forward by the same steamer from Suez, that there shall be an interval of from 6½ to 7½ days between the time of posting a letter for the same destination in the east. Thus precisely the same occurs in the reverse direction, that is to say, if the writer of a letter in London wishes to forward it, on account of its comparatively cheap rate of postage, _viâ_ Southampton so that it shall arrive in, say, Bombay, at the same time as a letter despatched _viâ_ Marseilles on the _evening_ of the 10th of the month, he must take care that it is posted in time for despatch by the _morning_ mail of the 3rd; or if the writer of a letter in Bombay forward it for delivery in England _viâ_ Southampton, he must be content that his correspondent receive it seven days later than if he sent it _viâ_ Marseilles; as the usual time for a letter to be conveyed between London and Bombay _viâ_ Marseilles, is twenty-one days, the letter if sent by the other route, is practically one-third longer on its journey. The _comparative_ penalty in time is not so great for Calcutta and other places more distant than Bombay, but the absolute penalty is the same in all cases, a delay of six days and a half as a minimum, seven days and a half as a maximum. When the Brindisi route is available for the mails now taken _viâ_ Marseilles, the interval, in consequence of the saving of thirty-nine hours, between the despatch of the mails, _viâ_ Brindisi and _viâ_ Southampton, must never be less than eight days as a minimum, or more than nine days as a maximum. The consequence is, in my opinion, that arrangements must be made for conveying, by the Brindisi route, the great portion of the “HEAVY,” or “SOUTHAMPTON MAILS,” as well as the conveyance of the “FAST,” or the “MARSEILLES MAILS.” It can, however, only be accomplished by the countries interested consenting to take a transit rate, very different from that which is the ordinary transit rate for mail correspondence.