Stamp No. Original printD25.1 Dr. Sun 1st LondonD25.2 Martyrs PeipingD25.3 Dr. Sun 1st London The domestic postal rate for ordinary letters was raised from 4¢ to 5¢ per unit in 1937. The 4¢stamps then in stock were more than required. As they were of same green color as the 5¢, the two stamps were apt to be confused at the sale windows. Therefore, a part of the 4¢stamps were surcharged as 1¢ to be used in combination with the remaining stock of 4¢stamps(not surcharged). The 25¢and 40¢stamps, not in great demand, were surcharged as 10¢and 8¢respectively. The surcharge work was done by the Peiping Printing Bureau of the Ministry of Finance. Stamps of these three denominations were surcharged in No.4 Regular-Writing characters on the two vertical sides in the middle and with Arabic figures at the bottom in red or black. The 1¢stamps were placed on sale in March 1937 and the 8¢and 10¢stamps in July 1938.