Abstract: This paper introduces two private letters of Liu Songling (Augustion F. Hallerstein), director of the Imperial Board of Astronomy, which discussed the thirteenth year of the Qianlong Reign. This was an extraordinary year which witnessed a serious situation regarding missionary cases, the Jinchuan war, the death of the Empress, and a restrained state policy. Hallerstein’s invaluable letters provide a supplement to Chinese materials and a different perspective on these historical events.