Kong ji ge zhi (Investigation into the phenomena in the atmosphere) is a scientific work by Gao Yizhi (Chinese name of Alfonso Vagnoni, 1566−1640). This work, in two juan, introduces in detail the Western theory of the four elements: earth, air, fire, and water, which are discussed in juan one. Juan two explains various natural phenomena related to the four elements, such as meteors, meteorites, thunder and lightning, comets, the Milky Way, colors of the sky, rainbows, wind, rain, clouds, fog, snow, hail, ice, dew, and frost. Each juan is preceded by a table of contents. Juan one begins with a subtitle Kong ji ge zhijuan shang (Part one of Kong ji zhi ge). This is followed by the authors' names in the next three lines: “Ji Xi Yesu hui shi Gao Yizhi zhuan” (written by Gao Yizhi, a Jesuit Missionary from the Far West); “Gujiang hou xue Han Yun ding” (revised by your pupil Han Yun of Gujiang); and “Nanjiang hou xue Chen Suoxing yue” (reviewed by your pupil Chen Suoxing of Nanjiang). Only juan one is presented here.