The documents refer to the discovery of possibly the oldest representation of a hand-gun in the any civilisation. The discovery was made by Robin Yates in June 1985, when visiting the Buddhist cave-temples of Ta-Tsu in Szechuan, China. The discovery is described by Joseph Needham in Appendix A of SCC, Volume 5, Part 7 (See SCC2/152/2), and in a later paper, co-written with Lu Gwei-Djen and Pan Chi-Hsing [潘吉星 / Pan Jixing] of Academia Sinica, Beijing, China, entitled 'The Oldest Representation of a Bombard', ('Technology and Culture', July 1988). Many of the documents relate to the writing of that paper.