The second set of commemorative covers of Important Ancient Chinese Scientific and Technological Inventionswas released in Beijing on September 17. This collection aims to show China's long-standing history, culture, and scientific and technological civilization, spread scientific ideas, and uphold the spirit of science.

The second set contains nine commemorative covers, featuring the themes of Mawangdui map, the Grand Canal, astronomical records, herbaloism, rice cultivation, right triangle and its incircle, movable-type printing, copper caliper inventedbyWang MangintheXin Dynasty, and watertight bulkhead. The commemorative covers are exquisite and simple, elegant and solemn, rich and detailed in content and fullof fun.

This collection of commemorative covers was jointly launched by China Post, the Bureau of Science Communicationof Chinese Academy of Sciences and the National Communication Center for Science and TechnologyofCAST. Itisplanned that a total of 88 commemorative covers in 10 setswill be issuedbased on 88 designs of "Important Ancient Chinese Scientific and Technological Inventions" selected by the Institute for the History of Natural SciencesofCAS.The first set has been officially issued in May this year.