their collection from those still stored in Zhejiang. A signal gun appears in Korea by 1600. The Wu I Thu Phu Thung Chih or Illustrated Military Encyclopedia written in 1791 depicts a signal gun in an illustration. Folding screen: The folding screen is a type of furniture consisting of several frames or panels. Screens date back to China during the Eastern Zhou Dynasty period (771–256 BC). These were initially one-panel screens in contrast to folding screens. Folding screens were invented during the Han Dynasty (206 BC - AD 220). Depictions of those folding screens have been found in Han Dynasty era tombs, such as one in Zhucheng, Shandong Province. During the Tang Dynasty, folding screens were considered ideal ornaments for many painters to display their paintings and calligraphy on. Many artists painted on paper or silk and applied it onto the folding screen. The landscape paintings on folding screens reached its height during the Song Dynasty (960–1279). Forensic entomology: The Song Dynasty (960–1279) forensic science book Collected Cases of Injustice Rectified published by the Song Dynasty court judge, physician, medical scientist and writer Song Ci in 1247 contains the oldest known case of forensic entomology. In a murder case of 1235, a villager was stabbed to death and authorities determined that his wounds were inflicted by a sickle; this was a tool used for cutting rice at harvest time, a fact which led them to suspect a fellow peasant worker was involved. The local magistrate had the villagers assemble in the town square where they would temporarily relinquish their sickles. Within minutes, a mass of blow flies gathered around one sickle and none other, attracted to the scent of traces of blood unseen by the naked eye. It became apparent to all that the owner of that sickle was the culprit, the latter pleading for mercy as he was detained by authorities. Fragmentation bomb: The use of fragmentation in bombs dates to the 14th century, and first appears in the Ming Dynasty text Huolongjing. The fragmentation bombs were filled with iron pellets and pieces of broken porcelain. A heated mixture of salammoniac, tung oil, chin chih, scallion juice, and yin hsiu is poured into the bomb, coating the pellets. Once the bomb explodes, the resulting shrapnel is capable of piercing the skin and blinding enemy soldiers. Free reed aerophone: The musical pipe organ employing metal piston bellows had a long