Though injured in comparison by the higher site and loftier walls of the Patent-Office opposite, the Post-Office, in itself, is one of the most beautiful public buildings in Washington. It occupies the entire block situated on Seventh and Eighth streets west, and E and F streets north. Like the Treasury and Patent-Office, it incloses a grassy court-yard on which its inner offices look out. The architecture of the Post-Office is a modified Corinthian, and is regarded by critics as the best representation of the Italian palatial ever built upon this continent. It was designed chiefly by F. A. Walter, at that time architect of the Capitol, an artist who has left monuments of architectural beauty behind him in marble which, seemingly, can never perish. On the Seventh street side there is a vestibule, the ceiling of which is composed of richly ornamented marbles, supported by four marble columns; the walls, niches and floors are of marble, polished and tessellated. This is the grand entrance to the General Post-Office Department. The F street front affords accommodation to the city Post Office. It has a deeply recessed portico in the centre, consisting of eight columns grouped in pairs, and flanked by coupled pilasters supporting an entablature which girds the entire work. The portico is supported by an arcade which furnishes ample convenience for the delivery of letters, and the hurrying crowds which come after them. The Corinthian columns of this portico are each formed of a single block of marble, and each in itself is a marvel of architectural grace. The entrance for the mail wagons, on Eighth street, consists of a grand archway, the spandrels of which bear upon their face, sculpture representing Steam and Electricity, while a mask, representing Fidelity, forms the key-stone.