sentences:  Song Yingxing's famous work was the "Tiangong Kaiwu", or "The Exploitation of the Works of Nature", published in May 1637 with funding provided by Song's patron Tu Shaokui.The "Tiangong Kaiwu" is an encyclopedia covering a wide range of technical issues, including the use of various gunpowder weapons.Copies of the book were very scarce in China during the Qing dynasty (1644–1911) (due to the government's establishment of monopolies over certain industries described in the book), but original copies of the book were preserved in Japan.