Introduction: The text of the brick is vertically written. The characters are cut in intaglio and of regular scrip. Contents of  inscription: the official seal of Nanjing Ministry of Works. In the Ming Dynasty, there were six departments of Personnel,  Revenue, Rites, National Defense, Justice and Works. The Ministry of Works is in charge of project construction. Many  Of the Nanjing city wall bricks were fired by the Ministry of Works.