By the report of the Secretary of the Navy herewith communicated it appears that unremitted exertions have been made at the different navy-yards to carry into effect all authorized measures for the extension and employment of our naval force.  The launching and preparation of the ship of the line Pennsylvania and the complete repairs of the ships of the line Ohio, Delaware, and Columbus may be noticed as forming a respectable addition to this important arm of our national defense.  Our commerce and navigation have received increased aid, and protection during the present year.  Our squadrons in the Pacific and on the Brazilian station have been much increased, and that in the Mediterranean, although small, is adequate to the present wants of our commerce in that sea.  Additions have been made to our squadron on the West India station, where the large force under Commodore Dallas has been most actively and efficiently employed in protecting our commerce, in preventing the importation of slaves, and in cooperating with the officers of the Army in carrying on the war in Florida.

The satisfactory condition of our naval force abroad leaves at our disposal the means of conveniently providing for a home squadron for the protection of commerce upon our extensive coast.  The amount of appropriations required for such a squadron will be found in the general estimates for the naval service for the year 1838.

The naval officers engaged upon our coast survey have rendered important service to our navigation.  The discovery of a new channel into the harbor of New York, through which our largest ships may pass without danger, must afford important commercial advantages to that harbor and add greatly to its value as a naval station.  The accurate survey of Georges Shoals, off the coast of Massachusetts, lately completed, will render comparatively safe a navigation hitherto considered dangerous.

Considerable additions have been made to the number of captains, commanders, lieutenants, surgeons, and assistant surgeons in the Navy.  These additions were rendered necessary by the increased number of vessels put in commission to answer the exigencies of our growing commerce.

Your attention is respectfully invited to the various suggestions of the Secretary for the improvement of the naval service.

The report of the Postmaster-General exhibits the progress and condition of the mail service.  The operations of the Post-Office Department constitute one of the most active elements of our national prosperity, and it is gratifying to observe with what vigor they are conducted.  The mail routes of the United States cover an extent of about 142,877 miles, having been increased about 37,103 miles within the last two years.  The annual mail transportation on these routes is about 36,228,962 miles, having been increased about 10,359,476 miles within the same period.  The number of post-offices has also been increased