After the completion of the Northern Expedition and the unification of the whole country in 1928, the National Government adopted a national emblem consisting of a white sun against a background of a blue sky. The 2nd set of air mail stamps bearing the same design as used in the 1st Peiping Print but with the new national emblem on the rudder of the plane, was also printed in two-colored intaglio by the Peiping Printing Bureau of the Ministry of Finance. The stamps are commonly known as 〝二次航空〞(Air Mail Stamps of 2nd Print). The difference between these two prints is the national emblem painted on the rudder. See (P-22) and (P-23) below. On June 11, 1928, the Central Government ordered the change of the name of the old capital from Peking to Peiping. The name of the print was changed accordingly, but this set of stamps was numbered serially following the 1st Peking Print.