This establishment is conducted in an old building, quite too small, even if the United States Courts did not occupy a considerable portion of it. The square, in the centre of which it stands, is about 300 feet each on Old Levee, Custom-House, Front-Levee and Canal streets; and, from its peculiarly happy location, is well calculated for public improvement. Considering the great commercial importance of New Orleans, as being scarcely second to any city in the Union, it is a matter of congratulation that the government are now disposed to place her upon a more respectable footing, in regard to offices of this nature; which have been furnished in a princely style to some of the sea-ports that had less need of them. The immense revenue that flows into the treasury department here, demands a suitable edifice for the transaction of the business it creates. The site is the most eligible that can be imagined. The Post-Office, United States Courts, and warehouses for the storage of bonded merchandise, can all have ample accommodation within its limits; and a more desirable location for them cannot be found. An appropriation of $500 was made at the last session of Congress, to secure a suitable plan for the buildings to cover this spot. The plan has been prepared by Mr. Gallier, and is highly approved by those who have examined it. It is to be hoped there will be no unnecessary delay in completing a work, in which the public convenience and economy, as well the accommodation of the mercantile community, is so deeply interested. If Mr. Gallier's plan is adopted, all the above departments will be clustered together in one central spot, with ample room for each, and in a structure that will be at the same time a durable ornament to the city, and an honor to the nation. THE POST OFFICE Is located in the Merchants' Exchange. It has two business fronts, besides a passage way through the building, where letters and packages are received for mailing. The private boxes have their delivery here, where also the publishers of newspapers receive their exchanges and communications. The general delivery for English letters is in Exchange Place, those for letters in the foreign languages, and for the ladies, are on Royal street. The edifice seems to answer the purpose well; and, considering the extent of the establishment, the duties of the office have been managed much to the satisfaction of the public. But we look for something more worthy of the place, when the new Custom House shall rear its noble front to the _father of rivers_. THE STATE HOUSE