The enlightened policy by which a rapid communication with the various distant parts of the globe is established, by means of American-built sea steamers, would find an ample reward in the increase of our commerce and in making our country and its resources more favorably known abroad; but the national advantage is still greater--of having our naval officers made familiar with steam navigation and of having the privilege of taking the ships already equipped for immediate service at a moment's notice, and will be cheaply purchased by the compensation to be paid for the transportation of the mail in them over and above the postages received. A just national pride, no less than our commercial interests, would Seem to favor the policy of augmenting the number of this description of vessels. They can be built in our country cheaper and in greater numbers than in any other in the world. I refer you to the accompanying report of the Postmaster-General for a detailed and satisfactory account of the condition and operations of that Department during the past year. It is gratifying to find that within so short a period after the reduction in the rates of postage, and notwithstanding the great increase of mail service, the revenue received for the year will be sufficient to defray all the expenses, and that no further aid will be required from the Treasury for that purpose. The first of the American mail steamers authorized by the act of the 3d of March, 1845, was completed and entered upon the service on the 1st of June last, and is now on her third voyage to Bremen and other intermediate ports. The other vessels authorized under the provisions of that act are in course of construction, and will be put upon the line as soon as completed. Contracts have also been made for the transportation of the mail in a steamer from Charleston to Havana. A reciprocal and satisfactory postal arrangement has been made by the Postmaster-General with the authorities of Bremen, and no difficulty is apprehended in making similar arrangements with all other powers with which we may have communications by mail steamers, except with Great Britain.