The compiler of this work was Yao Guangxiao (1335−1419). His preface, dated 1406 and headed “Yao Guangxiao, Senior Buddhist Patriarch, Junior Preceptor of the Heir Apparent and Duke of Rongguo,” recounts the origin and process of the work’s compilation. Yao Guangxiao, Buddhist name Daoyan, courtesy name Sidao, style names Du’an Laoren and Taoxuzi, was a native of Changzhou Xian (present-day Suzhou, Jiangsu), and an important figure in the late Yuan and early Ming dynasties. He became a Buddhist monk at the age of 14, but he later entered political life. The work has a second preface, written in 1463 by Xu Youzhen (1407−72), the heading of which reads: “By Xu Youzhen, Senior Vice Censor-in-Chief of the Chief Surveillance Bureau, Superintendent of the Grand Canal, Hanlin Academician, Minister of Ministry of War, Grand Academician of the Huagai Hall, and of Wenyuange, and Duke of Wugong.” This preface informs the reader that Yao was a monk who began to study works on astronomy, geography, waterways, and the legal calendar, concentrating particularly on works of cosmology. He is described as working in his room until late at night, in all seasons. Yao’s compilation gives detailed predictions, particularly relating to military affairs. The work was originally kept at the imperial court, but a copy was circulated beyond the court, which Xu Youzhen acquired and treasured. Xu profusely praises the work for its prognostications of good and ill fortune, “just as predicted, like pointing the finger at the palm of your hand.” He gives two examples of accurate predictions. First, in the seventh month of the year of 1448, Mars moved into the Southern Dipper and did not retreat—and by the eighth month the Tumu Crisis occurred and Emperor Yingzong was captured by the Oirats. Second, in the seventh month of the year 1456 a comet was seen in the west, with its length covering half of the sky—and in the first month of the following year Emperor Yingzong (Zhengtong reign 1436−49; Tianshun reign 1457−64) was restored to the throne. Juan 1 and Juan 2 discuss the Three Enclosures, with illustrations depicting the Three Enclosures and the Seven Mansions of the East, the North, the West, and the South Palace, and the nearby constellations. Quotations from Bu tian ge (Songs of pacing the heavens), an ancient verse book with illustrations of the skies, appear at the end of each enclosure and each of the Four Palaces of the 28 Mansions. The author records 283 constellations in the Three Enclosures and 28 Mansions, with 1,463 stars. Juan 2 contains hand-painted illustrations of the shapes of the 28 Mansions, two for each, with the Daoist symbol fu zhuan in red in the upper portion and a stellar symbol in black in the lower part; however, one of the 28 Mansions, jiao su, has four illustrations in two groups. Juan 3 contains part one of the discussion on degrees and distances of the sun and moon. Juan 4 continues with the discussion on the sun and moon, and astrology. Juan 5 discusses the dividing line between celestial regions and terrestrial realms and continues part one of the discussion of miscellaneous astrology. Juan 6 continues the discussion of miscellaneous astrology, as well as covers wind angles. Juan 7 is on wind and rain; and Juan 8 on weather forecasting, natural calamities, and unusual natural phenomena. In the table of contents of this copy, instead of the term wang qi (forecasting weather), the term qi xiang (meteorological phenomena) is used. The prefaces, table of contents, and Juan 1−2 are presented here.