The subject certainly deserves full and careful investigation, but it should not be delayed longer than can be avoided.  In the meantime there are certain works which have been commenced, some of them nearly completed, designed to protect our principal seaports from Boston to New Orleans and a few other important points.  In regard to the necessity for these works, it is believed that little difference of opinion exists among military men.  I therefore recommend that the appropriations necessary to prosecute them be made.

I invite your attention to the remarks on this subject and on others connected with his Department contained in the accompanying report of the Secretary of War.

Measures have been taken to carry into effect the law of the last session making provision for the improvement of certain rivers and harbors, and it is believed that the arrangements made for that purpose will combine efficiency with economy.  Owing chiefly to the advanced season when the act was passed, little has yet been done in regard to many of the works beyond making the necessary preparations.  With respect to a few of the improvements, the sums already appropriated will suffice to complete them; but most of them will require additional appropriations.  I trust that these appropriations will be made, and that this wise and beneficent policy, so auspiciously resumed, will be continued.  Great care should be taken, however, to commence no work which is not of sufficient importance to the commerce of the country to be viewed as national in its character.  But works which have been commenced should not be discontinued until completed, as otherwise the sums expended will in most cases be lost.

The report from the Navy Department will inform you of the prosperous condition of the branch of the public service committed to its charge.  It presents to your consideration many topics and suggestions of which I ask your approval.  It exhibits an unusual degree of activity in the operations of the Department during the past year.  The preparations for the Japan expedition, to which I have already alluded; the arrangements made for the exploration and survey of the China Seas, the Northern Pacific, and Behrings Straits; the incipient measures taken toward a reconnaissance of the continent of Africa eastward of Liberia; the preparation for an early examination of the tributaries of the river La Plata, which a recent decree of the provisional chief of the Argentine Confederation has opened to navigation—­all these enterprises and the means by which they are proposed to be accomplished have commanded my full approbation, and I have no doubt will be productive of most useful results.

Two officers of the Navy were heretofore instructed to explore the whole extent of the Amazon River from the confines of Peru to its mouth.  The return of one of them has placed in the possession of the Government an interesting and valuable account of the character and resources of a country abounding in the materials of commerce, and which if opened to the industry of the world will prove an inexhaustible fund of wealth.  The report of this exploration will be communicated to you as soon as it is completed.