On this day, 184 years ago, on April 16, 1841 (March 25, 1841, the Qing government dismissed Qi Shan and appointed Lin Zexu to co-ordinate Haiphong. On April 16, 1841, during the Opium War, due to the change of public opinion in the ruling and opposition and the attitude of Emperor Daoguang, Qi Shan was dismissed from his post and Lin Zexu was ordered to go to the Zhejiang Military Camp with the title of Fourth Grade Qing to assist in coastal defense affairs. After Lin Zexu arrived in Zhejiang, he actively planned and devoted himself to making cannons and practicing cannons every day. He awarded the gun-making techniques and eight warship schematics he collected and studied in Guangdong to Gong Zhenlin, Wang Shaohai and others, and promoted them to create new warships that combined China and the West., which surprised the British; Invented the iron mold for casting guns 30 years earlier than Europe; and manufactured the millstone gun cart for heavy artillery. In the winter of 1940, Lin Zexu wrote a letter to Emperor Daoguang, proposing that "making artillery must be extremely profitable, and building ships must be extremely strong" and "using power to defeat rebellion." Judging from his thoughts and practice in Zhejiang Province, Lin Zexu was the first person in modern history of China to request the establishment of a modern national defense industry to resist aggression.