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卷17 志第12 律曆中

Volume 17 Treatises 12: Measures and the Calendar 2

Chapter 17 of 隋書 · Book of Sui
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1
Treatises on Measures and the Calendar, Part Two.
2
輿 西 西 便
The calendar records the ceaseless transformations of yin and yang, extrapolates from past reckonings to anticipate the future, aligns human affairs with the sun's course, and thus enables one to act ahead of Heaven itself. Among the celestial signs that hang in the heavens, none shines more brilliantly than the sun and moon; among the patterns by which vital force moves through the year, none is more reliable than the four seasons. The sun and moon drive one another in their courses and light comes into being; cold and heat succeed each other until the year is complete. In this way the pattern of Heaven and Earth is fulfilled and the full range of cosmic change is realized. Heaven has five numbers and Earth has five numbers; when these five positions are multiplied together, each pair combines in its proper way. Heaven's numbers sum to twenty-five and Earth's to thirty, giving fifty-five in all—the number by which transformation is achieved and the workings of spirits are carried out. The tally-sticks for qian total two hundred and sixteen, and those for kun one hundred and forty-four—three hundred and sixty altogether, matching the days of a full cycle. In this way yin and yang alternate in their operation. Hard and soft interact, the four emblems take their places, and the eight trigrams stand in order—is this not the primal source of written pattern and the very beginning of calendrical reckoning? From the Flame Emperor, who divided the eight seasonal nodes, through the Yellow Emperor, who established the five bureaus; from Shaohao, who entrusted the calendar to the phoenix bird, and Zhuanxu, who set the southern director to oversee Heaven; from Yao, who appointed He and Zhong, to the Xia, who fully codified the Great Plan—through the revolutions of Tang and Wu, all followed established calendrical precedent. Yet as ritual forms changed from age to age, so did the calendar's new year and first month; hence the Son of Heaven appointed officials of the sun, and feudal lords maintained their own calendrical officers, to harmonize the myriad states and keep the three celestial markers in accord. The signs of cold and heat, light and dark, the reckoning of yin and yang's generative and destructive phases, the cycles of opening and closing and of rising and falling, and the rhythms of waxing and waning—all matched the celestial stations without deviation. Thus the calendar could embrace all living things, span Heaven and Earth, open the way for human enterprise, and reach to the farthest depths. When Zhou's virtue waned, the historiographers neglected their duties, calendrical experts dispersed, and no one any longer attended to omens and portents. When Qin conquered the realm, it embraced the theory of cyclical conquest among the five phases, claimed the auspicious token of the Water Virtue, and made the tenth month the year's beginning. In the Han dynasty's early years, many reforms went unattended, and for more than a century the Qin calendar remained in use. Under Emperor Wu, the dynasty adopted the Xia calendar's first month as the new year. Six ancient calendrical schools were then in circulation, and scholars questioned their inaccuracies. Liu Xiang and his son examined them thoroughly, and Ban Gu drew on their work for his treatise. When Emperor Guangwu restored the Han, no thorough calendrical review was undertaken. Not until the end of the Yongping reign was the Quarter-Remainder calendar reinstated; only after more than seventy years were its procedures fully established. Later Liu Hong and Cai Yong were again commissioned to revise the standards of pitch and calendar, and Sima Biao incorporated their work into his continuation of Ban Gu's history. When the Cao Wei dynasty took power, it too maintained calendrical officers: Han Yi devised a system first, and Yang Wei followed, both adopting Liu Hong's methods but falling short of his depth and refinement. Under both the Western and Eastern Jin, the calendar underwent repeated revisions. Western Liang likewise employed an obscuration-cycle calendar, but the records are too confused to recount in detail. In the Song dynasty's Yuanjia era, He Chengtian devised a new calendar that remained in continuous use until the end of Qi. When Emperor Wu of Liang came to power, he initially retained Qi's calendar; only in mid-Tianjian did he adopt Zu Chongzhi's Jiazi Origin Calendar from the Liu Song. When Emperor Wu of Chen accepted the throne, he introduced no calendrical innovations. Later, Emperor Wenxuan of Northern Qi adopted the calendar of Song Jingye. When Western Wei entered the Guanzhong region, Li Yexing devised a new calendar. Under Emperor Wu of Northern Zhou, Zhen Luan created the Jiayin Origin Calendar, which was then adopted for calendrical computation. At the start of the Daxiang era, Senior Grand Astrologer Ma Xian submitted the Bingyin Origin Calendar, which was adopted at once. In Kaihuang 4 the calendar of Zhang Bin was adopted; in Kaihuang 17 that of Zhang Zhouxuan was restored, and it remained in use until the Yining era. What follows selects the chief calendrical revisions of the five dynasties since Liang's Tianjian era and records them in this chapter.
3
使
Early Liang, following Qi, continued to use the Song dynasty's Yuanjia Calendar. In Tianjian 3 an edict ordered the calendar to be fixed. Supernumerary Gentleman Attendant Zu Geng memorialized: "My family has held this office for generations, going back to the Jin dynasty. Tracing from the Yellow Emperor down through twelve dynasties, each age has used a different calendar origin, with varying values for the celestial circuit and the dipper fraction; every dynasty in turn has handed down its own system. In the Liu Song's Daming era, my ancestor examined the ancient method and established the correct calendar, transmitting it to posterity. Its predictions have always been verified, and it should not be changed." In Tianjian 8, Zu Geng submitted another memorial on the matter. An edict ordered Grand Astrologer Jiang Daoxiu and others to compare the old and new calendars by observing seasonal nodes, new moons, conjunctions, and the motions of the seven luminaries from the eleventh month of Tianjian 8 through the seventh month of Tianjian 9. The new calendar proved accurate; the old one did not. Zu Geng then reported: "The He Chengtian calendar currently used by the historiographers already diverges from the heavens; its underlying principles are inconsistent and cannot be maintained. By imperial order it was sent to the Observational Platform to be tested against the new calendar. Predictions were made a hundred days in advance and verified twice over. From last winter through the current new moon, the results have been reported month by month. The motions of the seven luminaries rest on principles of extraordinary subtlety; lose the underlying reckoning even once, and the error compounds with every passing year. The calendar submitted may be adopted and should take effect from the coming new year." In the first month of Tianjian 9, Zu Chongzhi's Jiazi Origin Calendar was adopted and the new year's calendar was promulgated. By Datong 10 an imperial decree ordered a new calendar: jiazi as the origin, 619 as the cycle year, 1,536 as the day divisor, one degree of precession at the winter solstice over 183 years, and new-moon small remainders determined by the moon's anomalistic motion, yielding three long months and two short months. Before it could be implemented, Hou Jing's rebellion broke out, and the project was abandoned.
4
退 穿 使 退退 宿 退 1
Chen, following Liang, also used Zu Chongzhi's calendar without further modification. When Emperor Wenxuan of Northern Qi took the throne, he ordered Gentleman Attendant Song Jingye, drawing on prognostic charts, to create the Tianbao Calendar. Jingye reported that according to the Chart of Grasping Sincerity and the Wrapping of the Primordial Mandate, Qi would receive the mandate at the end of Wei's era; thirty-five multiplied yields the obscuration cycle, and 676 the cycle year." Emperor Wenxuan was delighted and ordered the calendar into use. The calendar summary reads: "From the upper origin in jiazi to Tianbao 1 (gengwu), the accumulated count is 110,506 beyond the epoch; cycle year 676, degree divisor 23,660, dipper fraction 5,787, calendar remainder 162,261." In Wuping 7 under the last ruler, Dong Jun and Zheng Yuanwei objected: "Song Jingye shifted the intercalary month to the celestial new year, deferred the epoch to the winter solstice conjunction, placed it after two long months, and at the third month's conjunction arbitrarily reduced the equal division. We find that Jingye's learning did not reach to the hidden depths, and his understanding was shallow. Though he intended reform, he mostly followed old formulas, merely swapping one constant for another—a forced and arbitrary contrivance that misses true principle. The result was solar positions off by as much as eight degrees, seasonal nodes lagging behind the heavens, and intercalary months arriving a month too early. For new and full moons and eclipses, he could not determine their limits; nor could his anomalistic reckoning be cross-checked by any alternative method. He arbitrarily imposed equal divisions and falsely shifted the winter solstice; this reduced the day count below a full year, and his arbitrary equal division caused the hour of occurrence to fall on the wrong day. The five planets' appearances and disappearances were off by as much as twenty days; their direct, retrograde, and stationary motions sometimes missed by two lunar lodges. His orbital methods arbitrarily predicted floods and droughts. We now submit the Jiayin Origin Calendar, with 657 as the cycle year, 22,338 as the obscuration cycle, 5,461 as the dipper fraction, and the jiazi day of the jiayin year as the epoch." Two men from Guangping, Liu Xiaosun and Zhang Mengbin, also shared responsibility for calendrical matters. Mengbin had studied under Zhang Zixin; both men abandoned the old system and devised new methods. Zhao Daoyan measured gnomon shadows to determine the sun's advance and retreat, and reconstructed the solar anomaly tables to calculate eclipse dates. Liu Xiaosun used 119 as the cycle year, 8,047 as the era, 966 as the year remainder, jiazi as the upper origin, and set the solar degree to begin at the middle of the Xu lodge. Zhang Mengbin used 619 as the cycle year, 48,900 as the era, 948 as the day divisor, and 14,945 as the dipper fraction. Their origin and era shared a single epoch; the method was compact in form but far-reaching in design. The sun, moon, and five planets all began from the eleventh degree of the Dipper lodge. Solar anomaly tables, rotating degrees, and the yin-yang divisions at the solstices matched the clepsydra graduations; gnomon shadows agreed as well, cycling without end. From the Spring and Autumn period down through the Tian Tong calendar, when solar and lunar eclipses and the positions of the five planets were checked against their new methods, every case matched. That year Gan Jingli and the calendrical specialists competed to predict the solar eclipse in advance. On the wushen-day new moon of the sixth month, a solar eclipse occurred. Liu Xiaosun predicted it for the mao hour, Zhang Mengbin for the jia hour, Zheng Yuanwei and Dong Jun for the chen hour, and Song Jingye for the si hour. When the eclipse came, it fell between the mao and jia hours; none of them was correct. The dispute was never resolved before the state fell.
5
沿 簿
The Nine Chapters, Five Records, Triple Concordance, and Quarter-Remainder calendars all share one purpose: to regulate the seasons, measure gnomon shadows and celestial coordinates, govern the realm, and grant the proper seasons—the very pivot of imperial rule. Yet the celestial axis is hard to measure, the dipper standard easily drifts, solar anomaly periods go awry, and calamities follow in their wake. It is not only that snakes sometimes usurp the dragon's place and water overcomes fire; jade sheep dim their radiance and golden roosters lose their brilliance as well. Imperial fortunes rise and fall with the calendar; a dynasty's ascent and decline depend upon it. The calendar's timely significance could hardly be greater. From the Han through Wei, across four dynasties and a millennium, calendrical officers were never absent from the court, yet the calendar origin and new-moon promulgation were revised again and again. Tested at close range, predictions may align; traced over centuries, they fall out of sequence. How can one simply follow precedent? The need for reform is clear. Great Zhou received the mandate, embracing all antiquity; drawing on Xia and Yin, it weighed the achievements of former dynasties. Its calendar used renzi as the cycle and jiayin as the origin. Emperor Gaozu, probing hidden principles to the utmost, judged that although this calendar was in use, it had not reached perfection. He issued an edict seeking advice from the finest scholars of the age and ordered Senior Grand Astrologer Ma Xian and others to revise it until it was right. Yet calendrical experts held divergent views; eight schools in all submitted calendars, varying widely in quality, and none was fully satisfactory. Last winter Emperor Xiaoxuan ordered us to supervise comparative testing and jointly devise a new calendar. We have examined the historiography bureau's old records and the numerical methods of all schools, discarded weaknesses and selected strengths, and jointly established the present system. The epoch begins from bingyin; for eclipses of the sun and moon and the appearances and disappearances of the five planets, accumulated verification shows it to be the most precise. Thus the iron-and-charcoal test will not miss the proper balance of cold and warmth, and the clepsydra's floating and sinking markers will not deviate from the measure of yin and yang. From the upper origin in bingyin to Daxiang 1 (jihai), the accumulated count is 41,554. Day divisor: 53,563, also called the obscuration-conjunction divisor. Cycle year: 448; dipper fraction: 3,167; obscuration divisor: 12,992. The cycle medial serves as the cycle-conjunction divisor. Day divisor: 53,563; calendar remainder: 29,693; conjunction period: 173 days; conjunction remainder: 16,619; winter solstice sun at the twelfth degree of the Dipper lodge. Small circuit remainders and solar anomaly accumulations are computed separately for entry into obscuration and conjunction, using a yang rate of 499 and a yin rate of 9. Below each of the twelve months are rotating eclipse fractions; by adding and subtracting these in computation, one obtains the fixed large and small remainders of the eclipse and determines the correct hour of occurrence.
6
使 使
This method was adopted. At that time Gaozu was chief minister, preparing the transfer of the throne, and wished to display tokens of the mandate to the world. The Daoist Zhang Bin, sensing the ruler's intent, claimed mystical insight and mastery of astronomy and calendrics. He spoke at length of signs that the mandate was changing and declared that Gaozu's bearing was not that of a mere subject. He thereby won great favor and remained constantly at Gaozu's headquarters. At the start of his reign, Gaozu promoted Zhang Bin to Inspector of Huazhou and commissioned him together with Liu Hui, Dong Lin, Gong You, the former Senior Grand Astrologer Ma Xian, Erudite Zheng Yuanwei, Ren Yue, Zhang Che, Zhang Yingzhi, Heng Hongjian, Su Xiang, Guo Di, Liu Yi, Zhang Qianxu, Wang Junrui, Xun Longbo, and others to devise a new calendar, with Minister of Ceremonies Lu Fen supervising the work. Zhang Bin and his colleagues based their work on He Chengtian's method with minor modifications. In the second month of Kaihuang 4 they completed the calendar and submitted it. Gaozu issued an edict: "Zhang Bin and his colleagues are devoted to computation, thoroughly versed in ancient and modern learning, and their reports have repeatedly offered valuable counsel. Your completed memorial has been received and fully reviewed. The following month begins its cycle without spilling past the last night of the month; the prior month's remainder rarely carries over to the next new-moon dawn. Adjusting from gibbous to crescent phase, it departs sharply from the old standard. The moon's path has inner and outer aspects with differing courses; when the sun crosses the node yet no eclipse occurs, it is because the crossing follows the yang path. Verified by timely calculation, the error does not exceed a hair's breadth—a secret that earlier masters had not yet unlocked. In each of these respects it is truly precise. It should be promulgated throughout the realm and put into use according to law."
7
The essential parameters of Zhang Bin's calendar:
8
From the upper origin in jiazi to Kaihuang 4 (jiachen year), the accumulated count is 4,129,001.
9
Obscuration divisor: 102,960.
10
Cycle year: 429.
11
Cycle month: 5,306.
12
Common month: 5,372,209.
13
Day divisor: 181,920.
14
Dipper fraction: 25,063.
15
Conjunction month: 1,297.
16
Conjunction rate: 221.
17
Conjunction number: 110½.
18
Conjunction fraction: 1,187,258,189.
19
Conjunction day divisor: 40,204,320.
20
Conjunction period: 173 days.
21
Remainder: 56,143.
22
Small fraction: 110.
23
Crossing divisor: 512,104,800.
24
Crossing fraction divisor: 2,815.
25
Yin-yang calendar: 13.
26
Remainder: 110,263.
27
Small fraction: 2,328.
28
New-moon difference: 2.
29
Remainder: 57,921.
30
Small fraction: 974.
31
Eclipse limit: 12.
32
Remainder: 81,303.
33
Small fraction: 433½.
34
Fixed difference: 44,548.
35
Circuit day: 27.
36
Remainder: 100,859. Also called the lesser great divisor.
37
The essence of Wood is Jupiter; its conjunction rate is 41,063,889.
38
The essence of Fire is Mars; its conjunction rate is 80,297,926.
39
The essence of Earth is Saturn; its conjunction rate is 38,925,413.
40
The essence of Metal is Venus; its conjunction rate is 60,119,655.
41
The essence of Water is Mercury; its conjunction rate is 11,931,125.
42
宿 退 使
Once Zhang Bin's calendar was adopted, Liu Xiaosun and the Ji Province scholar Liu Chuo both challenged its errors, declaring that its methods lacked proper foundation and its eclipse predictions missed the mark. They raised six objections. First: He Chengtian did not recognize the error in distributing intercalary months and used the seven-intercalation-in-nineteen-years rule. Second: Zhang Bin and his colleagues did not account for the shifting discrepancy in lodge degrees and kept the winter solstice at a fixed position. Third: when the heavenly markers align, the seven luminaries must share a single origin, yet they assigned separate origins to the five planets. Fourth: Zhang Bin and his colleagues knew only that when the solar qi remainder is exactly exhausted one may set the origin, but did not grasp that without sun-moon conjunction, new-moon dawn and winter solstice cannot be fixed. Fifth: Zhang Bin and his colleagues merely clung to a fixed origin method and did not account for advance and retreat. Sixth: Zhang Bin and his colleagues knew only to add the rotating large remainder of twenty-nine to obtain the new moon, but did not understand using sun-moon conjunction as the basis for fixing it. These six points are subtle matters—the great framework of calendrical science and the common method of sages—yet Liu Hui did not grasp them. This was indeed viewing the heavens through a bamboo tube. In verifying shadows to fix the seasonal nodes, He's method was superior; Zhang Bin's deductions strayed ever further. In aligning new moons with Heaven, He's method was weaker; Zhang Bin followed and traced that mistaken path. In short, they discarded the essence and kept the chaff. They also noted that under Emperor Ming of Wei, Secretariat Gentleman Yang Wei revised the Jingchu Calendar and submitted a memorial refuting earlier errors: "The hour of occurrence lags behind Heaven, and the eclipse does not fall on the new moon. Yang Wei's intent was to treat eclipse-on-new-moon as the standard, but he could not fully explain it or formulate the method. In the Liu Song's Yuanjia era, He Chengtian compiled a calendar whose submitted memorial stated: "The moon's motion is not uniform; it may be slow or fast. Conjunction and lunar eclipse do not always fall on new or full moon—this too departs from the calendar's intent. He Chengtian's original intent was to establish a conjunction method, but Pi Yanzong's obstruction prevented it from being implemented. Under Emperor Xian of Later Wei, Long Yidi again revised the Yanxing calendar and submitted a memorial: "Solar eclipses do not fall on the new moon, yet the practice persists; according to the Spring and Autumn Annals' eclipse records, Heaven verifies the new moon. These three were skilled calendrists of earlier ages; each had the right insight but failed to correct their written methods. Yet calendrical reckoning values above all the new moon and the seasonal nodes. The new moon heads the court assembly; the seasonal node marks the start of growth. The new moon has its rite of announcing provisions; the node has its suburban greeting ceremony. Confucius therefore fixed the calendar and established new-moon dawn and winter solstice as the model for posterity. Liu Xiaosun's calendar follows the explicit texts, using the moon's anomalistic motion to fix conjunction so that eclipses fall on the new moon, not on the last or second day of the month. Even if months frequently alternate one short and three long, this accords with Heaven's unity. The method has three parts in all, listed below.
43
First: verify that solar eclipses always fall on the new moon.
44
It cites the Odes: "At the crossing of the tenth month, on the xinmao day of the new moon, the sun was eclipsed. Calculated by the Jiazi Origin Calendar, the match is exact. The Spring and Autumn Annals records thirty-five solar eclipses. Of twenty-seven eclipses where the classic records a new moon, calculation with the Jiazi Origin Calendar matches exactly. Eight eclipses are recorded without the new-moon character. The Zuo Commentary says: "Failure to record the new moon was an error of the officials." The Gongyang Commentary says: "Failure to state the new moon means the eclipse was on the second day." The Guliang Commentary says: "Failure to state the new moon means the eclipse was on the last day." Calculated by the Jiazi Origin Calendar, all eight fall on new-moon days. Zuo Qiuming received the classic directly from Confucius and is far more reliable; the Gongyang and Guliang commentaries are speculative interpretations.
45
The Zuo Commentary, Duke Yin year 3, second month, day jisi: a solar eclipse. Calculation confirms conjunction on the jisi-day new moon.
46
Duke Zhuang, year 18, spring, third month: a solar eclipse. Calculation confirms conjunction on the renzi-day new moon.
47
Duke Xi, year 12, third month, day gengwu: a solar eclipse. Calculation confirms conjunction on the gengwu-day new moon.
48
Year 15, summer, fifth month: a solar eclipse. Calculation confirms conjunction on the guiwei-day new moon.
49
Duke Xiang, year 15, autumn, eighth month, day dingsi: a solar eclipse. Calculation confirms conjunction on the dingsi-day new moon.
50
The 181 solar eclipses recorded by the Former and Later Han, Wei, and Jin—whether dated to new moon, last day, or day before last—all calculate as new-moon eclipses under the Jiazi Origin Calendar.
51
The Former Han recorded forty-five eclipses in all. Three fell one day before the last day; thirty-two on the last day; ten on the new-moon day.
52
The Later Han recorded seventy-four eclipses in all. Thirty-seven fell on the last day; thirty-seven on the new-moon day.
53
Wei recorded fourteen eclipses in all. Four fell on the last day; ten on the new-moon day.
54
Jin recorded forty-eight eclipses in all. Twenty-five fell on the last day; twenty-three on the new-moon day.
55
Second: verify the changing discrepancy in celestial degrees.
56
Third: verify by seasonal nodes and gnomon shadow length.
57
使
The Spring and Autumn Apocrypha, Calendar Sequence Command, states: "Duke Xi of Lu, year 5, first month, day renzi, new-moon dawn, winter solstice. Calculated by the Jiazi Origin Calendar, the match is exact. The History of Song records that in Yuanjia 10, He Chengtian measured shadows with an earth gnomon and found the winter solstice had already drifted by three days. An edict ordered external verification from Yuanjia 13 through Yuanjia 20; over eight years, winter solstice consistently differed from the longest-shadow day by three days. Calculated by the Jiazi Origin Calendar, every winter solstice matches the longest-shadow day exactly. The details are as follows:
58
Thirteenth year (bingzi),
59
Celestial first month, day 18: calendar notes winter solstice;
60
Day 15: longest shadow;
61
This matches the present calendar's winter solstice.
62
Fourteenth year (dingchou),
63
Celestial first month, day 29: calendar notes winter solstice;
64
Day 26: longest shadow;
65
This matches the present calendar's winter solstice.
66
Fifteenth year (wuyin),
67
Celestial first month, day 11: calendar notes winter solstice;
68
Overcast—no shadow could be measured;
69
Present calendar: winter solstice on day 8.
70
Sixteenth year (jimao),
71
Celestial first month, day 21: calendar notes winter solstice;
72
Day 18: longest shadow;
73
This matches the present calendar's winter solstice.
74
Seventeenth year (gengchen),
75
Celestial first month, day 2: calendar notes winter solstice;
76
Day 29: longest shadow;
77
This matches the present calendar's winter solstice.
78
Eighteenth year (xinsi),
79
Celestial first month, day 13: calendar notes winter solstice;
80
Day 10: longest shadow;
81
This matches the present calendar's winter solstice.
82
Nineteenth year (renwu),
83
Celestial first month, day 29: calendar notes winter solstice;
84
Overcast—no shadow could be measured;
85
Present calendar: winter solstice on day 22.
86
Twentieth year (guiwei),
87
Celestial first month, day 6: calendar notes winter solstice;
88
Day 3: longest shadow;
89
This matches the present calendar's winter solstice.
90
調宿 輿
The new calendar had just been promulgated. Zhang Bin enjoyed Gaozu's favor, and Liu Hui attached himself to Bin and was promoted to Grand Astrologer. The two men colluded to attack Liu Xiaosun, accusing him of slandering the official calendar and making willfully eccentric claims. Liu Chuo falsely backed them, sowing confusion among scholars of the day. Liu Xiaosun, Liu Chuo, and their allies were ultimately dismissed on other pretexts. After Zhang Bin's death, Liu Xiaosun, then Assistant Magistrate of Ye County, resigned and went to the capital to submit his calendar again. Liu Hui repeatedly blocked him, and the proposal went nowhere. Liu Xiaosun remained attached to the Grand Astrologer's office as a direct appointee, unrewarded for years, lodging at the Observational Platform. He then brought his writings; his disciples carried his coffin to the palace gates, where he prostrated himself and wept. Law officers detained him and reported to the throne. Gaozu was moved and consulted Director of the Imperial Academy He Tuo. He Tuo endorsed the work, and Liu Xiaosun was immediately promoted to Grand Commander and ordered to compare his calendar with Zhang Bin's. Earlier, Zhang Zhouxuan of Xindu, skilled in computation, had served under the Grand Astrologer in obscurity for years. Now he joined Liu Xiaosun in attacking Zhang Bin's calendar. Conflicting opinions multiplied and remained unresolved for a long time. In the seventh month of Kaihuang 14, the emperor ordered an inquiry into solar eclipse predictions. Yang Su and others reported: "The Grand Astrologer's office submitted twenty-five eclipse predictions. Only four—one on the last day and three on new moons—even roughly matched the event, and those missed the correct hour and origin. The rest failed entirely. Zhang Zhouxuan's predictions were consistently accurate; the times and fractional parts matched like tally and seal. Liu Xiaosun's predictions were verified in more than half the cases. Gaozu then summoned Liu Xiaosun, Zhang Zhouxuan, and the others and personally received them. Liu Xiaosun then demanded that Liu Hui be executed before the calendar could be fixed. Gaozu was displeased and dismissed him again. Liu Xiaosun soon died. Yang Su, Niu Hong, and others mourned him and again recommended Zhang Zhouxuan. The emperor summoned Zhang Zhouxuan, who spoke on the lengthening of days and shortening of shadows. Gaozu was greatly pleased, richly rewarded him, and ordered him to help fix the new calendar. When Liu Chuo learned of Zhang Zhouxuan's promotion, he revised Liu Xiaosun's calendar, renamed it the New Method of the Seven Luminaries, and submitted it. It diverged significantly from Zhang Zhouxuan's method. Yuan Chong and Zhang Zhouxuan worked against him. Liu Chuo was dismissed again. By Kaihuang 17, Zhang Zhouxuan's calendar was complete and submitted. The emperor entrusted it to Yang Su and others to evaluate its merits. Liu Hui and Academy Assistant Instructor Wang Yi defended the old calendar, trading refutations with Zhang Zhouxuan. Calendar Officer Liu Yi drew on ancient histories and shadow records to challenge him, stating:
91
The Calendar Sequence Command records Duke Xi's fifth year, celestial first month, day renzi, new-moon dawn, winter solstice. The Zuo Commentary records Duke Xi's fifth year, first month, day xinhai, new moon, winter solstice. Zhang Bin's calendar: celestial first month, renzi-day new moon, winter solstice—matches the Calendar Sequence Command, differs from the Zuo Commentary by one day. Zhang Zhouxuan's calendar: celestial first month, renzi-day new moon—matches the Calendar Sequence Command, differs from the Zuo Commentary by one day; Third day, jiayin, winter solstice—off by two days from the Calendar Sequence Command, three from the Zuo Commentary. Duke Cheng, year 12: the Calendar Sequence Command records celestial first month, xinmao-day new-moon dawn, winter solstice. Zhang Bin's calendar: celestial first month, xinmao-day new moon, winter solstice—matches the Calendar Sequence Command. Zhang Zhouxuan's calendar: celestial first month, xinmao-day new moon—matches the Calendar Sequence Command; Second day, renchen, winter solstice—off by one day from the Calendar Sequence Command. Duke Zhao, year 20: the Zuo Commentary records second month, jichou-day new moon, winter solstice; the Calendar Sequence Command records gengyin-day new-moon dawn, winter solstice. Zhang Bin's calendar: celestial first month, gengyin-day new moon, winter solstice—matches the Calendar Sequence Command, differs from the Zuo Commentary by one day. Zhang Zhouxuan's calendar: celestial first month, gengyin-day new moon—matches the Calendar Sequence Command, differs from the Zuo Commentary by one day; Second day, xinmao, winter solstice—off by one day from the Calendar Sequence Command, two from the Zuo Commentary. Liu Yi argues that according to the Calendar Sequence Command and the Zuo Commentary, in every year when the intercalary remainder is exhausted, new-moon dawn and winter solstice must coincide. Checking the Spring and Autumn Annals' thirty-seven eclipses against the Calendar Sequence Command yields numerous matches; checking against the Zuo Commentary yields very few—proving the Commentary is in error. Zhang Zhouxuan arbitrarily sets intercalation by personal judgment; the seasonal nodes and new moons diverge from both the Calendar Sequence Command and the Zuo Commentary. Of seven Yuanjia-era winter-solstice shadow records, Zhang Bin's calendar matched five and missed two—both one day early. Zhang Zhouxuan's calendar matched three and missed four—all one day late. Yuanjia 12, eleventh month, jiayin-day new moon; fifteenth day, wuchen, winter solstice; longest shadow. Zhang Bin's calendar: wuchen winter solstice. Zhang Zhouxuan's calendar: jisi winter solstice—one day late. Yuanjia 13, eleventh month, jiyou-day new moon; twenty-sixth day, jiaxu, winter solstice; longest shadow. Zhang Bin's calendar: guiyou winter solstice—one day early. Zhang Zhouxuan's calendar: jiaxu winter solstice—correct. Yuanjia 15, eleventh month, dingmao-day new moon; eighteenth day, jiashen, winter solstice; longest shadow. Both calendars agree on jiashen winter solstice. Yuanjia 16, eleventh month, xinyou-day new moon; twenty-ninth day, jichou, winter solstice; longest shadow. Zhang Bin's calendar: jichou winter solstice. Zhang Zhouxuan's calendar: gengyin winter solstice—one day late. Yuanjia 17, eleventh month, yiyou-day new moon; tenth day, jiawu, winter solstice; longest shadow. Zhang Bin's calendar: jiawu winter solstice. Zhang Zhouxuan's calendar: yiwu winter solstice—one day late. Yuanjia 18, eleventh month, jimao-day new moon; twenty-first day, jihai, winter solstice; longest shadow. Zhang Bin's calendar: jihai winter solstice. Zhang Zhouxuan's calendar: gengzi winter solstice—one day late. Yuanjia 19, eleventh month, guimao-day new moon; third day, yisi, winter solstice; longest shadow. Zhang Bin's calendar: jiachen winter solstice—one day early. Zhang Zhouxuan's calendar: yisi winter solstice—correct.
92
退
From Northern Zhou's Tianhe 1 (bingxu) through Sui's Kaihuang 15 (yimao), fourteen winter and summer solstice shadow records are available. Zhang Bin's calendar matched ten and missed four—three one day early, one one day late. Zhang Zhouxuan's calendar matched five and missed nine—eight one day late, one one day early. Tianhe 2, eleventh month, wuxu-day new moon; third day, gengzi, winter solstice; longest shadow. Zhang Bin's calendar: gengzi winter solstice. Zhang Zhouxuan's calendar: xinchou winter solstice—one day late. Tianhe 3, eleventh month, renchen-day new moon; fourteenth day, yisi, winter solstice; longest shadow. Zhang Bin's calendar: yisi winter solstice. Zhang Zhouxuan's calendar: bingwu winter solstice—one day late. Jiande 1, eleventh month, jihai-day new moon; twenty-ninth day, dingmao, winter solstice; longest shadow. Zhang Bin's calendar: bingyin winter solstice—one day early. Zhang Zhouxuan's calendar: dingmao winter solstice—correct. Jiande 2, fifth month, bingyin-day new moon; third day, wuchen, summer solstice; shortest shadow. Zhang Bin's calendar: jisi summer solstice—one day late. Zhang Zhouxuan's calendar: gengwu summer solstice—two days late. Year 3, eleventh month, wu-wu-day new moon;, day 20, ding-chou, Winter Solstice, longest shadow. Zhang Bin's calendar matches ding-chou winter solstice; Zhang Zhouxuan's calendarwu-yin winter solstice; —one day late. Year 6, eleventh month, geng-wu-day new moon;, day 23, ren-chen, Winter Solstice, longest shadow. Zhang Bin's calendar matches ren-chen winter solstice; Zhang Zhouxuan's calendargui-si winter solstice; —one day late. Xuanzheng Year 1, eleventh month, jia-wu-day new moon;, day 5, wu-xu, winter solstice, longest shadow. Both calendars agree on wuxu winter solstice. KaihuangYear 4, eleventh month, ji-wei-day new moon;, day 11, ji-si, Winter Solstice, longest shadow. Zhang Bin's calendar matches ji-zi winter solstice; Zhang Zhouxuan's calendargeng-zi winter solstice; —one day late. Year 5, eleventh month, jia-yin-day new moon;, day 22, yi-hai, Winter Solstice, longest shadow. Zhang Bin's calendar: jiaxu winter solstice—one day early. Zhang Zhouxuan's calendar: gengchen winter solstice. Year 7, fifth month, yi-hai-day new moon;, day 9, gui-wei, Summer Solstice, shortest shadow. Summer Solstice,, Summer Solstice. Eleventh month, ren-shen-day new moon;, day 14, yi-you, Winter Solstice, longest shadow. Zhang Bin's calendar matches yi-you winter solstice; Zhang Zhouxuan's calendarbing-xu winter solstice; —one day late. Year 11, eleventh month, ji-mao-day new moon;, day 28, bing-wu, Winter Solstice, longest shadow. Zhang Bin's calendar matches bing-wu winter solstice; Zhang Zhouxuan's calendarding-wei winter solstice; —one day late. Kaihuang 14, eleventh month, xinyou-day new-moon dawn, winter solstice. Zhang Bin's calendar: eleventh month, xinyou-day new-moon dawn, winter solstice. Zhang Zhouxuan's calendar: xinyou-day new moon; renchen day 2, winter solstice—one day late. Jiande 4, fourth month (long), yiyou-day new moon; thirtieth day, jiayin—the moon was visible in the morning eastern sky. Zhang Bin's calendar: fourth month (long), yiyou new moon; day 30, jiayin—morning moon in the east. Zhang Zhouxuan's calendar: fourth month (short), yiyou new moon; fifth month (long), jiayin new moon—morning moon in the east. Liu Yi argues that the longest shadow marks winter solstice and the shortest marks summer solstice. Of twenty-four solstices verifiable from ancient records, twenty-one have shadow data and three record the solstice day without shadow measurements. The calendar then in use matched eighteen cases; six did not. Zhang Zhouxuan's calendar matched eight cases and missed sixteen—two by two days, fourteen by one day. In Kaihuang 4, winter solstice shadows measured at Luoyang and the capital agreed to the finest precision at both locations. From Northern Zhou's Tianhe era onward, all verified cases fall one day late. Further review found Jiande 4: on the last day of the month at new moon, the moon was sighted in the morning east; Zhang Zhouxuan's calendar: fifth-month new-moon day—the moon visible in the morning east. Examining Kaihuang 17: Zhang Bin's calendar places the intercalary month in the seventh month; Zhang Zhouxuan's in the fifth. Since intercalation should be determined by the solstice, and Zhang Zhouxuan's solstice is wrong, his intercalary placement must be incorrect. The official calendar frequently assigns long fourth and fifth months; Zhang Zhouxuan's frequently assigns long ninth and tenth months. His new-moon reckoning is weak, producing long months in later morning hours—hence the waning moon appears in the eastern morning sky on new-moon day.
93
西 滿 西 西滿 西 滿 西滿 滿 滿 西 西 西 西 西 滿 滿
Liu Yi also cites Kaihuang 4, twelfth month, day 15 (guimao): per the calendar the moon was at 3° Ghost; hour you; moon above mao; eclipse magnitude 9/15; obscuration began in the northwest. Observed: at the first watch, first tally, obscuration began at the northeast limb, magnitude 10/15; restored by the fourth tally; fully restored by the second watch, first tally. Kaihuang 5, sixth month, day 30: per the calendar, solar eclipse; sun at 6° Seven Stars; hour of occurrence mid-wu; magnitude 1.5/15; obscuration began at the southwest limb. Observed: eclipse began after the sixth quarter-hour of wu; obscuration from the northwest, magnitude 6/15; restoration began after the first quarter of wei; full restoration by the fifth quarter. Kaihuang 6, sixth month, day 15: per the calendar, lunar eclipse; hour you; moon above mao; magnitude 9.5/15; obscuration from the southwest; clouds obscured the moon at the time. By chen-si hours the moon appeared through clouds, already two-thirds eclipsed from the northeast; after totality clouds closed again. Restoration began around si-wu; by afternoon a break in the clouds showed the moon fully restored. Tenth month, day 30 (dingchou): per the calendar, solar eclipse; sun at 9° Dipper; hour chen slightly weak; magnitude 9/15; obscuration from the northeast. Observed: sun one zhang above the horizon at sunrise; eclipse began at chen 2; obscuration from the west, two-thirds magnitude; restoration after chen 2; full restoration by si 3. Kaihuang 10, third month, day 16 (guimao): per the calendar moon at 7° Di; hour xu; moon well past chen; magnitude 7.5/15; obscuration from the northeast. Observed: at first rising south of mao the moon was half eclipsed; by early chen about two-thirds; gradual restoration; fully restored before wei. Official calendar, ninth month, day 16 (gengzi): moon at 4° Stomach; hour chou; moon above wei; magnitude 3.5/10; obscuration from the east. Observed: eclipse began due east at the second quarter after wu; briefly turning south; at exact wei, four-fifths of the southern limb eclipsed; gradual restoration; full by shen 1.5. Kaihuang 12, seventh month, day 15 (jiwei): per the calendar moon at 7° Room; hour xu; moon above chen; magnitude 12.5/15; obscuration from the northwest. Observed: at the first watch, third tally, obscuration began northwest at about two-thirds magnitude—matching the calendar prediction. Kaihuang 13, seventh month, day 16: per the calendar moon above shen; magnitude 0.5/15; obscuration from the southwest. On the night of the 15th, watching from the fourth watch: at the fifth watch, first tally, obscuration began northeast at half magnitude; then lost in clouds. Kaihuang 14, seventh month, day 1: per the calendar, hour si weak; magnitude 12.5/15. By wei 3 the sun was eclipsed from the northwest at about half magnitude; lost in clouds; briefly visible during totality but not yet restored; then obscured again. Kaihuang 15, eleventh month, day 16 (gengwu): per the calendar moon at 17° Well; hour hai; moon above si; magnitude 9.5/15; obscuration northwest. That night after the first watch, fourth tally: moon above chen, eclipse began southeast; by second watch, third tally, moon above si, about two-thirds; gradual restoration; by third watch, first tally, moon above bing, fully restored. Kaihuang 16, eleventh month, day 16 (yichou): per the calendar moon at 17° Well; hour chou; moon above wei; magnitude 12.5/15; obscuration from the southeast. Observed on the night of the 15th: by third watch, first tally, moon above bing seen through clouds, already about 3/15 eclipsed from the east; totality at ding; restoration from the southeast; by fourth watch, third tally, moon at end of wei, fully restored. Yet Zhang Zhouxuan could not fully hit the mark.
94
The parties traded refutations until Gaozu was perplexed and no decision was reached for a long time. Then Palace Attendant Yan Minting submitted a memorial: "Under the Han, Luoxia Hong revised the Zhuanxu Calendar into the Taichu Calendar, declaring that after eight hundred years it would err by one day. The account appears in Zhang Zhouxuan's biography. Gaozu wished to invest the matter with portentous significance and issued an edict: "Having received the mandate, We rule the realm, seeking to revive sage teaching and expand the statutes—aligning with Heaven above and granting the seasons to the people below, searching far and wide for masters of calendrical science. Cavalry Commandant Zhang Zhouxuan, deep of mind and vast in skill, devoted to the Way into old age, submitted his calendar method. He was ordered to compare his calendar jointly with the Grand Astrologer's existing system. Observing the heavens and verifying against the armillary sphere, Zhang Zhouxuan's reckoning matched the seven luminaries, while the Grand Astrologer's system was largely erroneous. The assembled officials judged Zhang Zhouxuan's method the more precise. Grand Astrologer Liu Hui, Calendar Officers Guo Di and Liu Yi, and Cavalry Commandant Ren Yue—who had previously devised the calendar—were responsible for these errors. Direct Palace Attendant and Grand Astrologer Yu Jicai, Assistant Grand Astrologer Xing Jun, Calendar Officer Guo Yuan, and Erudites Su Can, Fu Jun, and Cheng Zhen—as calendrical officers—should have reviewed the system's accuracy. Yet they allowed this faulty calendar to remain in use without objection. Liu Hui and his colleagues already deserved punishment; instead they embellished errors and shielded faults, defying proper procedure. Yu Jicai and his colleagues deceived their superiors—conduct that could not be tolerated. Liu Hui and three others, the original authors of the faulty calendar, were stripped of rank; Yu Jicai and five others, who had concealed the fraud, were dismissed from office. Zhang Zhouxuan's calendar was entrusted to the relevant offices for implementation. Zhang Zhouxuan was promoted to Supernumerary Gentleman Attendant and appointed Grand Astrologer. Zhang Zhouxuan recommended Yuan Chong; they promoted each other, each claiming mastery in one area, and further burnished each other's reputations. Zhang Zhouxuan declared Yuan Chong's calendar the finest since antiquity; Yuan Chong declared Zhang Zhouxuan's calendrical art unmatched in all history. Zhang Zhouxuan studied Zu Chongzhi and also transmitted his master's methods. From this point forward, eclipse predictions largely hit the mark. The calendar adopted in Kaihuang 17 set the winter solstice at the fifth degree of the Xu lodge. Later its imprecision became apparent; by Daye 4, after Liu Chuo's death, Zhang Zhouxuan revised the method to set the winter solstice at the seventh degree of Xu, with further adjustments to various parameters, continuing until the Yining era. What follows records the calendar method fixed in the wuchen year.
95
From the jiazi origin to Daye 4 (wuchen): 1,427,644 years beyond the epoch.
96
Cycle year: 410.
97
Cycle intercalation: 51.
98
Cycle month: 5,071.
99
Day divisor: 144.
100
Month divisor: 33,783.
101
Chronogram divisor: 286.
102
Year fraction: 15572963.
103
Degree divisor: 42,640.
104
Submergence fraction: 5,191,311.
105
Submergence divisor, 21.
106
Circuit-of-heaven fraction: 15574466.
107
Dipper fraction: 10866.
108
Qi divisor: 469,040.
109
Qi-time divisor: 10660.
110
Circuit day: 27.
111
Day remainder: 1413.
112
Circuit common: 70209.
113
Circuit divisor: 2548.
114
Method for computing accumulated months:
115
From the origin to the year sought, multiply by the cycle month and divide by the cycle year to obtain accumulated months; the remainder is the intercalary remainder. If the intercalary remainder is 397 or above and winter solstice does not fall in that month, add one to the accumulated months.
116
Method for computing new moon, first quarter, full moon, and last quarter:
117
Multiply accumulated months by the month divisor; divide by the divisor to obtain one, yielding accumulated days; the remainder is the small remainder. Remove multiples of sixty from accumulated days; the remainder is the large remainder; count from jiazi beyond the tally—this is the new-moon day of the celestial first month of the year sought. The celestial first month establishes zi—now taken as the eleventh month of the prior year. If the new-moon small remainder is 547 or above, the month is long.
118
滿 滿 滿
Add seven to the large remainder and 437 plus three-quarters to the small remainder. One-quarter is "less," two-quarters is "half," three-quarters is "greater". When the small remainder fills the day divisor, remove it and carry to the large remainder. When it fills sixty, remove it; count as before—this is the first-quarter day. Add again to obtain full moon, last quarter, and the next month's new moon. If the new-moon remainder fills 537, the month is long; if reduced, use the small remainder.
119
Method for computing the twenty-four qi:
120
Multiply by month divisor intercalary remainder, cycle yearsmall remainder,, divide by qi divisor to obtain one,, count from new moon beyond tally, Winter Solstice. Divide remainder by eleven for day fractions.
121
滿滿 滿
:15, day fraction, small fraction1. Small fraction 8 carries to day fraction, day fraction full carries to days. Remove according to month length,, beyond tally,. Month without mid-season node is intercalary.
122
Method for finding solar anomaly at new and full moon upon entering qi:
123
Multiply days since entering qi by the decrease-increase rate; divide by 15 to get one; if the remainder is 8 or above, carry 1; . Apply decrease or increase to the anomaly value to obtain the fixed anomaly. Itsentering qi, divide by sixteen to obtain one, 1,.
124
Method for computing the Earth phase:
125
滿滿
27, day fraction, small fraction9. When small fractions reach 40, carry 1 to day fractions; when full, remove as before—this gives the day Earth begins to reign after the solstice.
126
Method for computing submergence days:
127
滿
Small fraction, day fraction, innersmall fraction,, submergence fraction. Nonesmall fraction, day fraction,. When full counts as days; remainder is day fraction; add days from new moon since entering qi; remove and count as before.
128
滿
:, day fraction. When day fraction fills submergence divisor, carry to days; remove and count as before.
129
Method for entering the slow-fast calendar:
130
滿滿
Accumulated days,,,, remainder is, beyond tally.
131
滿
To find the next month: add 2 days for a long month, 1 day for a short month; day remainders all 1,135; when full remove circuit day and day remainder.
132
滿
To find the next day: add 1; when full, remove as before.
133
Method for finding the hour of new/full moon entry into the calendar:
134
滿
Small remainder,, small fraction,.
135
滿
To find the next month: add 1 day and remainder 2,486, small fraction 21; when full remove as before—this gives next month calendar entry day and remainder.
136
滿
To find full moon: add 14 days, remainder 1,949, small fraction 21½; when full remove as before—this gives full-moon calendar entry day and remainder.
137
Method for computing fixed day and small remainder at new/full moon hour:
138
滿
Decrease-increase, decrease-increaseanomaly, 1, yielding fixed. Divide by difference divisor together with entering-qi fixed anomaly; all apply expansion-subtract and contraction-add to base new/full moon small remainder. When insufficient to subtract, add the day divisor and then subtract—the hour falls on the prior day. When adding, if it fills the day divisor remove it—the hour falls on the following day. Remainder is small remainder. When no eclipse occurs, solar anomaly correction is not required.
139
Horn 12°, Neck 9°, Root 15°, Room 5°, Heart 5°, Tail 18°, Winnowing Basket 11°.
140
宿
Eastern seven lodges: 75°.
141
Dipper 26°, Ox 8°, Girl 12°, Emptiness 10°, Rooftop 17°, Encampment 16°, Wall 9°.
142
宿
Northern seven lodges: 98°.
143
Legs 16°, Bond 12°, Stomach 14°, Hairy Head 11°, Net 16°, Turtle Beak 2°, Three Stars 9°.
144
西宿
Western seven lodges: 90°.
145
Well 33°, Ghost 4°, Willow 15°, Star 7°, Extended Net 18°, Wings 18°, Axletree 17°.
146
宿
Southern seven lodges: 112°.
147
Method for computing solar degree:
148
滿 宿滿宿
,,,, degree divisorand1, yielding accumulated,. ,,, beyond tally, Winter Solstice. Winter Solstice,, 1, degree divisor,,,. When the new-moon shared degree is needed, subtract the fixed day count used; apply as later required.
149
宿
To find the next month: add 30° for a long month, 29° for a short month; remove by lodge sequence; when passing the Dipper remove its fraction.
150
To find the next day: add 1°; remove and count as before.
151
Method for finding the sun degree at new/full moon hour:
152
滿滿
Small remaindercycle year,,,. At new-moon hour, the sun and moon share the same degree.
153
:, small fraction.
154
Method for finding the moon degree at full moon hour:
155
滿滿
,, 25, small fraction. When small fractions reach 1,040, carry 1 to rotating fraction; when rotating fractions reach 41, carry 1 to degrees; Remove and count as before; when passing Dipper remove 10 rotation fractions and 466 small fractions.
156
Method for finding fixed daily rotation fraction of lunar slow-fast motion:
157
滿退
Multiply midnight calendar-entry day remainder by rotation difference; divide by circuit divisor to obtain one—this is variation difference; advance-add and retreat-subtract to daily rotation fraction for fixed fraction.
158
Method for computing fixed midnight lunar degree at new and full moon:
159
滿滿
Small remainder, day divisor,,,.
160
滿
To find the next day: add the fixed daily rotation fraction to the rotation fraction; when 41 carry to degrees; remove and count as before. On new-moon day, the prior addition is not applied.
161
Method for computing the five planets:
162
Wood number (Jupiter): 7008332 and 4 parts.
163
Fire number (Mars): 33256026.
164
Earth number (Saturn): 6121767.
165
Metal number (Venus): 24898417.
166
Water number (Mercury): 4941098.
167
,, day fraction,.
168
,, day fraction,.
169
,, day fraction,.
170
,, day fraction,. Morning appearance and disappearance: 327 days, fractions the same. Evening appearance and disappearance: 256 days。.
171
,, day fraction,. Morning appearance and disappearance: 63 days, fractions the same. Evening appearance and disappearance: 52 days。.
172
Method for finding star appearances:
173
,,, degree divisor, day fraction, Winter Solsticemean appearance. For Venus and Mercury, subtract evening appearance-disappearance days; the remainder is evening mean-appearance day and fraction.
174
滿滿
To find mean appearance:Winter Solsticeremove parts, each Winter Solstice parts thereof , partswhen full degree divisorcarry to , celestial first month, remove , not when full as remove , beyond the tally, then that which at parts.
175
滿 滿
:, when full remove as before. For Venus and Mercury, add morning or evening respectively; when full, remove as before—adding morning yields evening, adding evening yields morning.
176
滿 滿
Jupiter: mean appearanceatSpring Equinox, Great Cold, mean appearance,, yielding fixed. Start of Autumn, Cold Dew,,. From spring equinox through Pure Brightness add 4 days uniformly; then through Start of Summer add 5; then through Grain in Ear add 6, uniformly through Start of Autumn. Lesser Snow, Cold Dew, mean appearanceday fraction. Winter Solstice, Great Cold,. From Lesser Snow through Winter Solstice uniformly subtract eight days, yielding the fixed day count. At first appearance and disappearance, each is fourteen degrees from the sun.
177
滿 滿
Mars: mean appearanceatRain Water, Great Cold. AtStart of Summerafter, Start of Autumn, add to appearance day fraction; when full remove as before. Rain Water through Start of Summer, uniformly add 29day. Lesser Snow, End of Heat. Winter Solsticeafter, Great Cold, when full remove as before and subtract. Lesser Snow through Winter Solstice, uniformly subtract 25day. At first appearance and disappearance, each is seventeen degrees from the sun.
178
滿
Saturn: mean appearanceatEnd of Heat, Great Heat. White Dewafter, Frost Descent, add to appearance day fraction; when full remove as before. From End of Heat through White Dew add 9 days uniformly. Lesser Cold, Frost Descent, Lesser ColdStart of Spring, Start of Spring, 7, 1, Grain Rain3, Summer Solstice1, Great Heat. At first appearance and disappearance, each is seventeen degrees from the sun.
179
滿滿滿 滿 滿
Venus: mean appearance, atStart of Spring, Lesser ColdLesser Fullnessafter, Summer Solstice, add to appearance day fraction; when full remove as beforeStart of SpringLesser Fullness. Start of Autumn, Lesser Heat, Lesser SnowWinter Solstice, when full remove as before and subtract, Start of AutumnLesser Snow. Mean appearance,, Lesser Snow. Pure Brightnessafter, Grain in Ear, when full remove as before and subtract, Pure Brightness. End of Heat, Summer Solstice. Cold Dewafter, Great Snow. When adding: from End of Heat through Cold Dew uniformly add 9 days. At first appearance and disappearance, each is eleven degrees from the sun.
180
滿
Mercury: morning mean appearance before Start of Summer and after Rain Water—should appear but does not. From Awakening of Insects through Rain Water, 18° to 46° from the sun—in the morning, if Jupiter, Mars, Saturn, or Venus is present, it appears. When absent, it is not visible. From Start of Summer through Lesser Fullness, solar distance as before—in the morning, if one or more of Jupiter, Mars, Saturn, or Venus is present, it appears. When absent, it is likewise not visible. From Frost's Descent through Lesser Snow add 1 day; from winter solstice through Lesser Cold subtract 4; from Start of Spring through Rain Water subtract 3. Winter Solstice, 3, 2, 1. Evening mean appearance after End of Heat and before Frost Descent—should appear but does not. Start of AutumnEnd of Heat,,,. When absent, it is likewise not visible. Frost DescentStart of Winter,,,. When absent, it is likewise not visible. Carry to Grain Rain through Summer Solstice, subtract2day. At first appearance and disappearance, each is seventeen degrees from the sun.
181
Method for computing the five planets' motions:
182
宿滿 滿
Set the star fixed-appearance prior midnight solar lodge degree count and fraction; add the fixed-appearance day fraction to each fraction; when full carry from the degree divisor to degrees. Take the star's first-appearance distance from the sun; subtract for morning, add for evening; when full, remove as before—this gives the star's first-appearance degree and fraction.
183
滿滿 退退
:, hassmall fraction,, small fraction, degree divisor. Its Fast motionSlow motion, 1 daily motion parts, each its partsFast motionSlow motion thereof . Stationary, then subtract thereof , disappearancenot °, directremove its parts, parts. When done, all reduce fractions by 1,040 to obtain large fractions, with 41 as the denominator.
184
退退
Jupiter :first appearance, direct , daily motion 618, daily decreasing slow 60, 114daily motion 19 and 3,832then stationary. 26then retrograde , 6,101, 84retrograde 12 and 804. Also stationary 25 days, 37,612 fractions, small fraction 4—then direct motion. Initial daily motion 3,837 fractions, increasing by 60 per day; in 114 days it travels 19° 13,718 fractions, then disappears.
185
退退
Saturn :first appearance, direct , daily motion 3,814, 83daily motion 7 and 8,082then stationary. 38then retrograde , 2,563, retrograde 6 and 460. Also stationary 37 days, 3,847 fractions, then direct at 3,813 fractions daily; in 83 days travels 7° 17,999 fractions—as initially—then disappears.
186
Mars: after first appearance, each phase follows its method:
187
滿 滿 退退
Rain Water, Lesser Cold, Lesser Fullnessafter, Great Heat. Divide by 3; subtract the result from days to obtain fixed days. Rain WaterLesser Fullness, yielding fixed. All preceding entries give the day and degree counts of the prior fast-motion phase. Winter Solstice, according todecrease-increase thereof, yielding fixed. Degree divisor, 1, namely uniform motion 1day fraction, small fraction. Great ColdStart of Autumn, remainder uniform motion. End of HeatWhite Dew,, 6. White DewCold Dew, daily motion, daily motion,. 1,, uniform motion 1day fraction, day fraction. , slow motion60fraction, slow motion. Daily motion 20,600, daily decreasing slow , 60daily motion 24 and 35,640fast remove , slow add 4,264, 60daily motion 30,. Then stationary. When thirteen days before leaving the sun, distribute fraction and days between two stationary phases; odd remainders go to the later stationary phase. Then retrograde , 2,082, 60retrograde 17 and 40. Also stationary , 139466 parts. ,, daily motion, daily increasing fast, daily motion,, Start of AutumnAutumn Equinox,, daily motion,. Then later fast motion.
188
When later slow motion adds 6°, subtract from later fast motion for fixed degrees; all prior entries give later-fast day and degree counts. Start of Summer, Lesser Heat, daily motion,,. Lesser HeatStart of Autumn,,. Compute remaining days and degrees according to the prior method. All preceding phases use uniform motion. To find motion fractions, proceed as before. Each completes its allotted days and degrees and disappears.
189
退退 滿 滿 退退西
Venus: first appearance,,, then stationary. Then direct,,,, daily motion. Before Lesser Heat, counting from Grain in Ear, reduce 1° every 10 days; After Start of Winter, counting from Great Snow, reduce 1° every 10 days; Lesser HeatStart of Winter, yielding fixed. From Great Snow through Grain in Ear, no addition or reduction. To find the initial day: multiply the degree divisor by 30; divide by 40 to obtain one equal fraction. Also 39multiply 250, subtract partsas daily motion parts. Uniform motion,, 15 daily motion. Lesser Cold, 1, Rain Water,. Uniformly through 10 days after spring equinox reduce by 1; through Lesser Fullness, again 15 days travel 15°. 1, End of Heat,. Frost Descentafter, 1, Winter Solstice15 daily motion, daily motion. When prior direct-slow reduces degrees, compute the reduction and add to this degree for fixed degree. 1 daily motion,, degree divisor, 1, uniform motion. Morning disappearance in the east. First appearance,,, daily motion. Summer Solstice, Lesser Fullness,. Lesser Heatafter, Start of Autumn,, Summer SolsticeLesser Heat, yielding fixed. White DewPure Brightness,, daily decreasing slow. Pure BrightnessWhite Dew, uniform motion, uniform motion,,,, daily motion. Uniform motion,, 15 daily motion. 10 days after winter solstice reduce days and degrees by 1 each; through Awakening of Insects, 9 days travel 9°. Uniformly through 5 days after summer solstice increase by 1; through Great Heat, again 15 days travel 15°. Uniformly through 6 days after Start of Autumn increase by 1; through Cold Dew, 25 days travel 25°. 1, Great Snow15 daily motion, Winter Solstice. ,,,,, daily motion. ,, daily motion. As with morning slow motion—only where it says subtract, add instead. Also stationary , 9 then retrograde , °, 15°, and evening disappearance.
190
西
Mercury: first appearance,. Direct, Slow motion, daily motion 660 parts, 4 daily motion 1°. From Great Cold through Rain Water, this slow-motion phase is not required. Uniform motion,, 10 daily motion. Great Cold, 1,,. Fast motion, daily motion 1°38376 parts, 10 daily motion 19°, prior none Slow motion, subtractthis parts2792 parts, 10 daily motion 16°. Morning disappearance in the east. Evening first appearance, direct, Fast motion, daily motion 1°38376 parts, 10 daily motion 19°. From Lesser Heat through White Dew reduce 12,792 fractions; in 10 days travel 16°. Uniform motion,, 10 daily motion. Great Heat, 1,,. Slow motion, daily motion 660 parts, 4 daily motion 1°. When fast motion reduces 12,792 fractions, this slow phase is not required. Also stationary 6, evening disappearance.
191
Method for computing crossings and conjunctions:
192
Conjunction common: 646729.
193
New-moon difference: 907057.
194
Full-moon difference: 453528 and a half.
195
Single number: 5323364 and a half.
196
Hour divisor: 32604.
197
Full-moon number: 5776893.
198
Outer limit: 4869836.
199
Inner limit: 193200 and a half.
200
Middle limit: 5649404 and a half.
201
Secondary limit: 320689.
202
Method for computing entry into crossing:
203
滿
Accumulated months,,, remainder is.
204
滿
To find full moon: add the full-moon number; when full, remove as before.
205
滿
To find the next month: add the new-moon difference; when full, remove as before.
206
Method for computing crossing inner/outer path and prior/later node distance:
207
滿 滿 滿
When new or full moon is before Awakening of Insects, multiply 1,380 by days since Lesser Cold. AtGrain Rainafter, Grain in Ear,, Grain Rain. When full, remove the conjunction common; the remainder is the fixed remainder. ItsLesser ColdSpring Equinox, Start of SummerGrain in Ear,,. At two hours or above, do not add. When new-moon crossing remainder is below full-moon difference and full-moon number, above middle limit, with star disappearance: Jupiter and Saturn 10+ days from appearance, Mars 40+, Venus morning disappearance 22+. When only one luminary is involved, do not add the qi difference. White Dew, Lesser Heat. AtStart of Winter, Great Snow,. White DewStart of Winter,,, remainder is. When new-moon crossing remainder is at outer/inner limit or above, with star disappearance below single-number secondary limit as before—do not subtract qi difference. When the fixed remainder is less than the single number, it is outside. When full, remove it; the remainder is inside. Remainder below full-moon difference and above outer limit—at full moon there is lunar eclipse. When inside the node, a solar eclipse occurs at new moon. The remainder below the full-moon difference is the prior-crossing remainder removed. ,, remainder is. Divide by the hour divisor to obtain one—this is the crossing hour count removed.
208
Method for computing lunar eclipse hour:
209
Small remainder,,, beyond tally,. The remainder is the hour remainder; multiply by 4; divide by the divisor—zero gives chronogram start, 1 is "less," 2 is "half," 3 is "greater". If still remainder, multiply by 3; divide by the divisor—one gives "strong"; combined with "less" gives "less-strong," with "half" gives "half-strong," with "greater" gives "greater-strong". Two "strong" gives "less-weak"; combined with "less" gives "half-weak," with "half" gives "greater-weak," with "greater" gives chronogram end. This hour of occurrence means the moon at opposition during the eclipse.
210
Method for computing solar eclipse hour:
211
滿
Small remainder,,,, 24,. In the third month of spring, inner path, node distance seven hours or above—add 24. ,, beyond tally,. The remainder is the time remainder. Set aside, when full,, or above. For seasonal chronograms, add half a chronogram directly; For primary chronograms subtract the chronogram divisor; add half a chronogram to the remainder for the difference rate.
212
滿退
Also,, 3, 2, 1,, 12. Multiply by the difference rate; divide by 14 to obtain one—this is the hour difference. Half half and half half , Multiply by add remainder. Half half and half half , Multiply by subtract remainder. ,,,,, remainder is. As with the lunar eclipse method: zi-wu-mao-you are mid-chronograms; chen-xu-chou-wei are seasonal chronograms; yin-shen-si-hai are primary chronograms. Solar eclipses more than two hours before sunrise or after sunset are not recorded. 1, beyond tally.
213
Method for finding solar eclipses on the outer path:
214
When node distance is within one hour, there is an eclipse. In summer, node distance within two hours, hour in the southern three chronograms—eclipse. If within twelve hours of an equinox or solstice, node distance within six hours—also eclipse. Spring Equinox,, Autumn Equinox,,. Prior crossing within two hours with expansion beyond two hours, or later crossing within two hours with contraction beyond two hours—also eclipse. Node distance3, stardisappearance, eclipse.
215
Method for finding when the sun is not eclipsed on the inner path:
216
西
Hour of occurrence3chronogram, 513, 613, noteclipse. Awakening of Insects through Grain Rain, 13, hour of occurrence, noteclipse. End of HeatFrost Descent,,,.
217
To find the lunar eclipse fraction:
218
Crossing and crossing and crossing , remove eclipse remainder 1, remove , eclipse. 30235, 1eclipsefraction. ,,, 15, remainder is.
219
Method for computing solar eclipse magnitude:
220
滿
AtAutumn Equinox, Summer Solstice,, remainder is. ,, remainder is. Yielding fixed. ,, yielding fixed. AtAwakening of Insects, Summer Solstice500. Autumn Equinox through Awakening of Insects, uniformly subtract 184000,, as before. Great ColdLesser Fullness,,. ,,, eclipsealready. Add , crossing add , crossing subtract. When the subtraction cannot be completed, an eclipse occurs.
221
西 西
To find the initial point: inner path northwest, obscuration northeast. Outer path southwest, obscuration southeast. At thirteen parts or above, begin at due left. Obscuration is always reckoned from maximum; for the moon it begins from the upper limb.
222
Method for finding.
223
Entering qi,, entering qi, divide by fifteen to obtain one, decrease-increasethat whichentering qi, yielding fixed.
224
General Table of Contents of the Book of Sui.
225
Book of Sui — General Table of Contents — Book of Sui, Volume 18, Treatise 13.
226
Treatises on Measures and the Calendar, Part Three.
227
滿
In Kaihuang 20, Yuan Chong memorialized that days were long and shadows short; Emperor Gaozu entrusted calendrical affairs to the Crown Prince and ordered further study of the signs of lengthening days. The Crown Prince summoned calendrical and computational experts from across the realm; all assembled at the Eastern Palace. Liu Chuo, as the Crown Prince had just been installed, further revised his work, titling it the Supreme Pole Calendar, to refute Zhang Zhouxuan's errors. The Crown Prince greatly approved it, but verification had not yet been obtained. Liu Chuo, as Imperial Academy Erudite, confident in his expertise, sought to supplant Zhang Zhouxuan; dissatisfied with his office, he pleaded illness and retired. By Renshou 4, Liu Chuo reported Zhang Zhouxuan's errors to the Crown Prince.
228
1, Zhang Zhouxuan, eclipse, stationary,,, through 5,. But it was achieved through others' work, not his own record; on examination, the discrepancies were very numerous.
229
Second: Zhang Zhouxuan's first quarter, full moon, last quarter, and new moon violate antiquity and are coarse; seasonal nodes, intercalation, and pentads deviate from Heaven's clear mandate. Hours do not begin from midnight; the morning before is separately counted as the following day. Solar motion fails to grasp fast and slow; lunar anomaly is arbitrarily made into two kinds; monthly rotation omits expansion-contraction; at conjunction crossings, qi difference is fabricated. 7,,,,,, obscurationeclipse,. ,, anomaly,. Polar distance and gnomon graduations should exist but do not; eclipse fraction sequencing is excessively tedious. Present measurements are unverified, ancient comparisons fail—the method's flaws are beyond reckoning. Now item by item refuted—536 entries in all.
230
, Multiply by , , , Multiply by. His calendar circulated widely with many copies; the version in circulation matches Liu Chuo's earlier calendar. Zhang Zhouxuan had prepared to submit his work at nearly sixty—this was not hastily composed; why, shortly after reaching the capital, did he change to match Liu Chuo's calendar, diverging from his earlier system; ?. Liu Chuo composed first, Zhang Zhouxuan submitted later—abandoning his own work to follow another, their differences secretly aligned. Moreover Xiaosun derived from Liu Chuo; Zhang Zhouxuan later attached to Xiaosun—the calendrical text was all Xiaosun's work; the original theft is quite clear. Zhang Zhouxuan,, in general75items,.
231
Fourth: as historiographer Zhang Zhouxuan himself reported eclipses; his submissions mostly contradicted the calendar—now calculated, his errors number thirteen. He had previously joined Grand Astrologer Liu Hui and others in comparing fifty-four points of accuracy, claiming fifty-three favored the new method. By later calculation the calendar should exceed the old in precision; yet in practical computation it proved coarser. Now refutations including prior entries—44 items in all.
232
Fifth: Zhang Zhouxuan was not thoroughly versed in calendrical science. Xiaosun,,,,,.
233
Sixth: Liu Chuo, by imperial order in Kaihuang 3, undertook revision, following recorded precedents, claiming precision unmatched since Qin and Han. ,, 7, 3,, 1, conjunction common,,,. Where Zhang Zhouxuan deviated, Liu Chuo's method agrees; what Zhang Zhouxuan lacked, the present system fully provides—embracing beginning and end, claiming completeness.
234
He also memorialized: "Since learning was silenced and texts burned, the people were scattered and the realm in turmoil; minor arts proliferated while calendrical officers vanished—the calendar lay in ruins for a thousand years. Liu Chuo, humble and unworthy, was mistakenly elevated; devoted to calendrical arts, immersed in numerology, striving from below the ranks of scholars to glimpse the sage's intent. At the start of Kaihuang, commissioned to compile—his nature ill-suited to others, his work unfinished—yet Zhang Zhouxuan stole it as his own method; failing to achieve perfection, frequently missing the seasons, holding office in name only while corrupting the calendar—a true stain on imperial policy. Request summoning Zhang Zhouxuan to answer and verify the merits and flaws; . 」.
235
Liu Chuo also compiled calendrical comparisons, titled Investigation of the Pole. Daye 1: Wang Shao and Zhuge Ying, attending a banquet, praised Liu Chuo's calendrical precision with clear evidence. The emperor said: "I have known this for a long time. He then ordered Liu Chuo's book sent to Zhang Zhouxuan for joint verification. Zhang Zhouxuan objected: "Liu Chuo's calendar has year rate and month rate, yet establishes fixed new moons, producing months with three long and three short. And , new moon cycle year and cycle month. , 3, 514. 3, 56. , 15. , as Multiply by , ,. Yielding fixed new moon,,. They traded refutations until no decision was reached, and Liu Chuo again retired.
236
4year,, Grand Astrologer: 「dayeclipse. The emperor summoned Liu Chuo, wishing to implement his calendar. , Zhang Zhouxuan,,,. Calendrical experts praised its subtlety, and its method is recorded here. Jiazi origin: 1008840.
237
Year rate: 676.
238
Month rate: 8361.
239
New-moon day divisor: 242.
240
New-moon dividend: 36677.
241
Ten-day circuit: 60.
242
New-moon chronogram: 3 and a half.
243
Day stem origin: 52.
244
Day limit: 11.
245
Expansion general: 16.
246
Obscuration, 17.
247
Method for computing mean new moon:
248
滿 滿滿
,, 1, yielding accumulated,. Accumulated months, day divisor1, yielding accumulated,. Accumulated days,, thenthe year sought.
249
To find first quarter and full moon: add 7 mean-new-moon days and 475¾ remainder for the first-quarter mean day and remainder. Also add to obtain full moon, last quarter, and the following month's new moon. Full moon , add 14 and remainder 950half. Quarter add 22 and remainder. 29, remainder659. Each month add 20 greater intercalary-decline units to obtain that month's intercalary decline.
250
滿 滿 滿滿 滿 滿滿 滿 滿 滿
The month establishing zi is the celestial first month; chou the terrestrial first month; yin the human first month. Multiply by as , ,. Carry to , and and and , , ,. 12month, 11month,. , alsocarry to,,. If the seasonal node falls after midnight, measure the shadow using the following day as the reference. In additive operations, subtract each remainder from the divisor; the residue is the full remainder. When full, 1,. Remainder less remainder , add , obtain. Degree fractions follow the same rule. Fractional parts of a day are remainders; accumulated remainders are called seconds. Fractional parts of a degree are fractions; accumulated fractions are called bamboo tallies. Incomplete seconds are called micro-units; incomplete bamboo tallies are called minima. And remainder and second and bamboo tally , 1as , 2as half , 3as , 4as , add when full carry to 1. Its3, 1, 2. ,, carry to. When full divisorcarry to 1, when full, thencarry to remove. , when full. Count and remainder and second and bamboo tally , carry to remove. When full, when full, carry to,. ,, 1,. , carry to. When terms share totals, full day-degrees, and fractions, add or subtract all full values and shared fractions together. For multiplication with fractions, convert denominators to include full values; after multiplying, divide back. To combine fractions with different denominators, cross-multiply numerators and combine. ,, when full divisorcarry to 1,. Divide as remainder , second bamboo tally , multiply divide , obtain second bamboo tally. ,, carry to 1,. When denominators differ, convert to common terms: multiply each fraction by the other's denominator, then divide to obtain the required numerator. ,, notwhen full,. The smallest fractional units follow the same rule. Divide remove , ,. , as when full and remainder and second and bamboo tally ,. Multiply by subtract , half and greater add subtract , remainder , Multiply by 4divide day divisor, Multiply by half greater and 3multiply , less and divide remainder add subtract. Autumn EquinoxafterSpring Equinox, Spring EquinoxafterAutumn Equinox,. ,, Spring Equinox, day fractionafter, day fraction. All unlisted cases follow this pattern.
251
Qi day divisor: 46644.
252
Year number: 7036466 and a half.
253
Degree standard: 338.
254
Approximation rate: 9.
255
Qi chronogram: 3887.
256
Remainder common: 897.
257
Second divisor: 48.
258
Micro-divisor: 5.
259
Method for computing seasonal nodes:
260
滿滿 滿
,,, 1, day divisor,. , Winter Solstice,, 1, when full, allyielding fixed day. Beyond tally, Winter Solstice. 943or below,. ,, 1, beyond tally,. Beyond the twelve chronograms lies the remainder after the start of zi. Also multiply the chronogram remainder by 12:
261
Four parts is "lesser-greater," also called "lesser." 5 equals half a step; 6 equals half;
262
7 equals half plus greater; Eight parts is "greater-lesser," also called "greater." 9 equals greater;
263
10 equals great plus greater; 11 equals exhausted chronogram less.
264
退 退 退
,, or below. Retrograde Multiply by as strong , Multiply by as weak. When the initial value does not reach one and retreats, this is called a stained chronogram; When eleven is initially formed with a carry, it is called an exhausted chronogram. ,,, day fraction. All separate categories follow this same standard. Winter Solstice subtract , add. Add 15 and remainder 192 and second 37, remainder. , Winter Solsticedivisor,. To find the next month's node constant day, subtract as for the prior node.
265
Method for computing daily slow-fast numbers:
266
調
, half , Multiply by multiply divide , obtain. Multiply subtract , divide , as. Multiply divide , as. Less , Multiply by subtract , as , add. When prior values are greater, add the total difference to the terminal rate to obtain each qi-initial-day ascent-descent value. By separate difference: subtract daily when prior is greater, add to the initial value when prior is less—yielding each day's value. , add and subtract slow , as slow. , , Multiply by as , add as , add , as , second ,.
267
:remainder is, entering qi,,,,, 1,. ,,, 1,,,,,. When prior is less: within the limit, square and multiply by the separate difference; square the day-limit, double and divide; add the total rate—all yielding total values. Multiply by add and subtract slow as , add and slow subtract remainder , conjunction slow remainder.
268
To find :,,. Slow motion, slow motion,.
269
滿
To find :,,,,, when full 1, 2 through 1. Multiply by add , count. Also compute the next entry; add and count in succession to obtain each fixed seasonal-node day and remainder. Using prior and later converted values: subtract first, then add to the constant qi to obtain the next fixed seasonal-node day and remainder. , jia-zi,.
270
滿 滿
To find the Earth phase: from each four-establishment point, four qi outward, apply prior-later adjustment; when full: 22 days, remainder 8,154, 10 seconds, 2 micro-units. Divide when full , Saturn.
271
滿
To find :then. Divide the constant qi by 3 to obtain each mean pentad day. Remainder Multiply by as remainder , Multiply by add and subtract , , remainder , when full , Multiply by add count , obtain. Also compute the next; add and count in succession to obtain the terminal pentad and next seasonal-node day.
272
Double the midnight clepsydra graduations to obtain night graduations. Subtract from 100 graduations; the remainder is day graduations. Subtract 5, Multiply by add , as and as. Clepsydra fractions use 100 as the denominator.
273
滿
To find :210,,. Half Multiply by half add , as , add , as. 1, beyond tally,,,.
274
To find pre-chronogram remainder: multiply midnight graduations by the qi/new-moon day divisor and divide by 100.
275
To find :15day, 225. Each solstice precedes and follows its adjacent equinox, with numbers added and subtracted accordingly, six seasonal nodes between each interval; 4, 3. Through 1,. For each pair of seasonal nodes, the daily increment decreases. ,, 6day,. The two full moons to the last day of the preceding and following qi; ending at ten plus a fraction; 2, 12, 20, 3, 21, 30. 4, 31, 35. 5, 36, 41. , 41, 42. , 80,,. Adding and subtracting night graduations and halving yields the fixed night graduations upon entering each seasonal node. 15,, set aside, 80, obscuration,. Subtract from the upper position; the remainder is the amount added. When less than a full day, apply the chronogram rate.
276
To find :1,,.
277
滿
To find :,, 43, 4001, 80,,. When full,,. ,, through, retrograde. Through,,. If through prior, byentering qi,,,, carry to retrograde,. , 《Investigation of the Pole》.
278
, 27. Remainder: 255.
279
Terminal divisor: 2263.
280
Terminal dividend: 62356.
281
Terminal full remainder: 8.
282
Rotation divisor: 52.
283
Bamboo-tally divisor: 897.
284
Intercalation limit: 676.
285
滿滿
Method for computing :accumulated days,,,,,,.
286
滿
:,, remainder is.
287
To find :,.
288
To find :addlong month2day, short month1day,,.
289
滿
To find :carry to rotation,,,. New moon , add 7 and remainder 865 and second , second when full day divisorremainder , obtain quarter. Full moon and quarter and new moon , add full moon 14 and remainder 731 and second 79half , quarter 22 and remainder 334 and second , new moon 1 and remainder 2,208 and second 917. New moon full moon 1, subtract remainder , full moon 531 and second 62half , new moon 54 and second 325.
290
Conjunction :Multiply by new moon quarter full moon conjunction slow , carry to remainder , add and slow subtract remainder , conjunction remainder.
291
Method for computing fixed new-moon, quarter, and full-moon days:
292
滿退 滿 滿滿 退
Multiply by conjunction add subtract , half , as. Subtract the two limits to obtain the limit-decline value. ,,, 1,. ,, 1,. ,, day divisorand1,. Carry to remainder as remainder , subtract and add remainder. , Multiply by subtract subtract , Multiply by add add , subtract , half , Multiply by multiply. , 2,,. 1,,, day divisorand1. Apply the result to reduce gibbous and add crescent to the limit number; adding and subtracting the gibbous-crescent accumulation fixes the phase. Subtract and add conjunction remainder , when full retrograde , new moon quarter full moon remainder. ,, beyond tally,. Whether subtracting or not, the new-moon day tally matches the following month. When neither has a standing tally, for a long month add the borrowed reduction tally after the fixed new-moon tally. When full , new moon as , when full , and , , new moon ,. ,, 2,. , 1day,,. ,,, 10. , add subtract , , less ,. 72011, 14759, 21507, 28or below,. , 9fraction, 7day8fraction, 14day7fraction, 21day6fraction, 28day5fraction. 7day1fraction, 14day2fraction, 21day3fraction, 28day4fraction. , 1,,,. ,,, uniform motion. Initial and final values exist that constant computation omits; on the 14th and 28th days initial and final numbers remain, yet empty decline also appears—numbers that should be removed but the standard method does not account for.
293
To find the chronogram added at new moon, first quarter, and full moon:
294
51or below,. ,, 1,, 12beyond tally,. For later chronogram strength-weakness, follow the qi method.
295
Method for finding entry into chronogram degree:
296
Degree divisor: 46,644.
297
Circuit number: 7037076.
298
Circuit fraction: 2016.
299
Rotation: 13.
300
Bamboo tally: 355.
301
Circuit difference: 609 and a half.
302
Remainder , bamboo tally , as day divisor and as degree divisor, ,. Where the Woman lodge ends connecting to Empty is called the circuit fraction. The variation circuit follows rotation—called rotation. Morning and evening solar distance is measured on the ecliptic against the equator.
303
Dipper 26°, Ox 8°, Girl 12°, Emptiness 10°, Rooftop 17°, Encampment 16°, Wall 9°.
304
宿
7, 98degree.
305
Legs 16°, Bond 12°, Stomach 14°, Hairy Head 11°, Net 16°, Turtle Beak 2°, Three Stars 9°.
306
西宿
7, 80degree.
307
Well 33°, Ghost 4°, Willow 15°, Star 7°, Extended Net 18°, Wings 18°, Axletree 17°.
308
宿
7, 12degree.
309
Horn 12°, Neck 9°, Root 15°, Room 5°, Heart 5°, Tail 18°, Winnowing Basket 11°.
310
宿
7, 75degree.
311
Prior entries are equatorial degrees with constant values, girdling the celestial pole as the armillary standard.
312
Method for computing the ecliptic:
313
宿
Winter Solstice, 4. 97, 1, 7. Its3,. 9, 1,, Spring Equinox. Thus for every 119, each limit reduces by 1; it also terminates at 109. Also3,. 7, 1,, Summer Solstice. Add Winter Solstice , obtain and Winter Solstice. , 81,,. , , , , , , as , , ,.
314
Dipper 24°, Ox 7°, Girl 11.5°, Emptiness 10°, Rooftop 17°, Encampment 17°, Wall 10°.
315
Northern lodges: 96.5°.
316
Legs 17°, Bond 13°, Stomach 15°, Hairy Head 11°, Net 15.5°, Turtle Beak 2°, Three Stars 9°.
317
西
Western lodges: 82.5°.
318
Well 30°, Ghost 4°, Willow 14.5°, Star 7°, Extended Net 17°, Wings 19°, Axletree 18°.
319
Southern lodges: 109.5°.
320
Horn 13°, Neck 10°, Root 16°, Room 5°, Heart 5°, Tail 17°, Winnowing Basket 10.5°.
321
Eastern lodges: 76.5°.
322
Prior entries are ecliptic degrees for stepping the sun's daily motion. The moon and five planets enter and exit by this method.
323
Method for computing lunar path degrees:
324
,, 11, 1, 1. Its3,. 1, 1, 11,. 11, 1, 1. Also3,. 1, 1, 11,,. Apply the eleven-fold increase-decrease to obtain later crossing and half-crossing values. , 801,. When the moon is outside, half after crossing before: apply decrease-subtract and increase-add. Half after crossing before: apply decrease-add and increase-subtract on the ecliptic. When the moon is inside, reverse each value to obtain the moon-path travel degree. 4degree,, 41. , outside and inside,,,,,, disappearance,,. When accumulated crossing difference is large, use the crossing as the standard. 5, outside and inside,,. When computation is unclear, assign degrees by the ecliptic.
325
Method for computing solar degree:
326
滿滿 宿滿宿
Set the year sought, yielding accumulated, remove,, when full degree divisor, notwhen full. Winter Solstice. 1lodge sequence, notwhen full beyond the tally, thenthe year soughtWinter Solstice.
327
To find the fixed new-moon degree for the year:
328
Winter Solsticeremainder is,, Winter Solstice,. , by through,,. , the remainder is fraction. For advance-retreat totals used in increase-decrease, increase the mean daily degrees before the fraction and decrease after.
329
To find the next day:
330
Daily advance-retreat fractional increase-decrease, added to the fixed new-moon degree, gives midnight position.
331
To find first quarter and full moon:
332
Remove daily entry fractions from the fixed new moon, accumulate increase-decrease, subtract fixed new-moon days, then add the fixed new-moon degree to obtain midnight position.
333
To find the next month:
334
Long month30day, short month29day,,, through.
335
To find the chronogram added at new moon, first quarter, and full moon:
336
, 1,. , day divisorand1,,,. Reduce by,,. , conjunction new moon.
337
Method for computing when the moon shares the sun's degree:
338
Multiply by new moon conjunction add subtract add subtract , as conjunction. Multiply by add subtract new moon , multiply , divide , Multiply by add subtract new moon add , conjunction. Multiply mean-conjunction remainder by the degree standard, divide by the approximation rate, subtract the chronogram position—to obtain mean-conjunction midnight solar position. 464,,, carry to,,. ,,, uniform motion. 502multiply , Multiply by multiply , new moon divide carry to , subtract and add , new moon ,. Multiply by conjunction obtain add subtract conjunction , obtain.
339
To find the fixed chronogram degree at first quarter and full moon:
340
Set the degree and fraction where first-quarter and full-moon chronograms fall; for first quarter add 91°, rotating fraction 16, bamboo tallies 313; 82, 32, 626. 273, 49, 42, all through,.
341
Fixed new-moon midnight entry into rotation:
342
,, yielding fixed.
343
New moon and quarter full moon and half , month divisoras.
344
Method for computing fixed daily lunar rotation fraction:
345
, 1,. Multiply by add and subtract , as.
346
To find the next day:
347
滿
, when full carry to degree,. Following daily rotation, add fixed days to obtain new-moon, quarter, and full-moon midnight lunar fixed degrees. Add Multiply by half , Multiply by half subtract , , remainder multiply , divide , half. ,, 1. ,, day divisorand1,,. From midnight, likewise compute the retreat fraction and add—this also gives the chronogram degree. Multiply by as bamboo tally , , , divide as rotation fraction. To find the fixed chronogram degree from mean new-moon midnight, subtract and compute the increase-decrease number, then find the fixed retreat fraction and apply it to midnight—yielding the fixed chronogram degree.
348
To find morning and evening lunar degrees:
349
,, 1,. Subtract the circuit fixed fraction to obtain the dusk fraction. Divide for rotation degree; before full moon use dusk, after use dawn; add to midnight fixed degree to obtain position.
350
To find morning and evening culminating stars:
351
滿 滿
Add the degree count to the midnight fixed degree to obtain the culminating star degree. New moon and quarter and full moon , Multiply by multiply remainder , when full day divisorobtain ,. ,, when full.
352
Return month: 5458.
353
Crossing month: 2729.
354
Crossing rate: 465.
355
Crossing number: 5923.
356
Crossing divisor: 7,356,366.
357
Conjunction divisor: 577530.
358
Crossing return days: 27. Remainder: 263. Second (time unit): 3435.
359
Crossing days: 13. Remainder: 752. Second (time unit): 4679.
360
,, 12. Remainder: 555. Second (time unit): 473 and a half.
361
,, 1. Remainder: 97. Second (time unit): 4205 and a half.
362
,, 2. Remainder: 395. Second (time unit): 2488.
363
Conjunction limit: 58. Remainder: 676. Second (time unit): 50 and a half.
364
Conjunction days: 73. Remainder: 384. Second (time unit): 283.
365
Method for computing lunar entry into crossing outside/inside:
366
滿 滿
Set accumulated months, remove,. ,, when full remove,. Notwhen full, thenthe year soughtoutside and insidenumber.
367
To find the next month:
368
滿
, when full remove,,.
369
Method for computing days of lunar entry into crossing:
370
滿滿
Multiply by new moon multiply , as crossing. Crossing divisor, 1,,, beyond tally,.
371
滿 滿
To find full moon:byfull-moon difference, when full remove, outside and inside. Remainders that do not fill carry back to the new moon. Eclipse,, outside and inside.
372
滿 滿
To find :new-moon difference, when full remove, outside and inside. Remainders that do not fill match the prior month.
373
To find mean new-moon and full-moon entry into crossing constant days:
374
Multiply by entering qinew moon full moon conjunction slow , add and slow subtract crossing remainder , as crossing remainder.
375
To find fixed new-moon and full-moon entry into crossing fixed days:
376
Multiply by crossing multiply , crossing 1, obtain Multiply by subtract and add remainder , new moon full moon remainder. When distance from the node is below full-moon difference but above the crossing limit, a lunar eclipse occurs; when the moon is inside the node, a solar eclipse.
377
Method for computing days of solar entry into conjunction:
378
滿
,,,, beyond tally,.
379
To find full moon:,, itsoutside and inside.
380
滿
Conjunction :Multiply by crossing multiply entering qinew moon full moon conjunction slow , crossing 1, Multiply by add and slow subtract conjunction remainder , remainder. Multiply by , subtract and add remainder , new moon full moon conjunction remainder. When full conjunction remove , new moon full moon remove conjunction , full moon Multiply by and conjunction Multiply by , eclipse. When the moon's path is outside and the sun's path inside the node, a solar eclipse occurs.
381
To find fixed new-moon and full-moon entry into crossing fixed day at midnight:
382
, 1,,.
383
To find the next day:
384
Multiply by slow , and new moon remainder , Multiply by add , obtain remainder.
385
To find the next month:
386
退 退
, long month2day, short month1day, 978, 2488. Multiply by slow , and add , as. 7day, remainder997, 2339or below,. , 244, 3583,. 14day, or below,. , 489, 244,. 5fraction, 7day4fraction, 14day3fraction. 71fraction, 142fraction,,.
387
退 退滿
:, remainder is,,,. ,, crossing divisor,. ,, crossing divisorand1. ,, crossing divisor,,,,. At new or full moon entry into crossing: if at the limit or above, subtract crossing days; the remainder is distance from the later crossing. If below full-moon difference, this gives the distance from the prior crossing. , 1, obtainnode distancechronogram. , eclipseeclipse. When the moon's path is outside the node, the sun should not be eclipsed—yet eclipses sometimes occur.
388
Method for computing expected eclipses that do not occur:
389
西
New moon within ten days of summer solstice, node distance less than 12 chronograms; 20, 12. 1, 12. And , Multiply by , add. Summer Solstice20, node distance13chronogram, 4chronogram. In intercalary fourth and sixth months, also add 4 chronograms. And End of Heat , add. And , add half Multiply by and half Multiply by. Spring EquinoxlaterAutumn Equinoxprior, 1chronogram. Node distances of 13.5 chronograms or more may also fail to produce an eclipse.
390
Method for computing unexpected eclipses:
391
New moon within one month of summer solstice, node distance 2 chronograms; 46, 1, 2chronogram. Also1, also1, add34chronogram, 463chronogram. And End of Heat , add less and greater. After Pure Brightness and before White Dew, add 2 chronograms. After spring equinox and before autumn equinox, add 1 chronogram. Allnode distanceor below, eclipse.
392
Method for computing lunar eclipse magnitude:
393
滿
, Summer Solstice3. Before its fraction, multiply the post-fraction qi count and add to the value after the fraction. 10node distance, node distanceremainder, eclipse. Full-moon difference, 961, notwhen full, chronogram divisor, 15,, eclipse.
394
Method for computing solar eclipse magnitude:
395
, Summer Solstice2, 2chronogram, node distanceremainder1. Add3chronogram, 1, add4chronogram,. 3, add2chronogram, 1chronogram. Add3chronogram,. Add4chronogram,. 4, add2chronogram,. Add35, add2chronogram,. Add , Start of Summer and , add , add , add. Within six seasonal nodes, adding two chronograms also follows the mean value. Add , remove Start of Summer and and and , , Multiply by 3subtract remove crossing remainder. Mercury and Frost Descent , half remove , Multiply by add 2remove , subtract remove crossing remainder. Winter Solstice , Multiply by remove Frost Descent and Mercury 3divide , Multiply by add Frost Descent Mercury obtain. Node distanceremainder, allyielding fixed noteclipseremainder. Full-moon difference, eclipsedivisor. , itsnode distance,, 1, 1, eclipsenumber. ,, node distance,,, 1, eclipsenumber. 15,, eclipse.
396
西 耀 耀
Eclipse,,,,, eclipse,. Though outside appears full while the moon is below, inside loses height; shallow crossings appear distant. When the crossing is deep, the bodies meet but do not fully cover each other. ,, that whicheclipse. Outer path, obscuration, eclipse. ,,, obscuration. Even assuming uniform winter and summer values, morning and evening observations differ. In southern chronograms the body appears higher; oblique viewing from east and west introduces skew. The logic cannot be unified—standard rates, though seemingly correct, still contradict observation. Ancient records conflict; here we summarize the outline for reference. Away from Yangcheng, all values gradually differ by location. Eclipse,,,,,,,, eclipse, 「eclipse,. 」,,, obscuration. Since the moon reflects sunlight, it shines brighter at noon; time also spans the earth without abolishing its received light. ,,, obscuration. , outside and insideeclipse. ,, eclipsefraction,,, obscurationnumber,,.
397
Method for computing the chronogram of solar eclipse:
398
滿
,,,, 3,,. Beyond the tally, notwhen full,,,,,. 10node distancechronogram, 3,, 141,. 21, thenyielding fixed difference. Winter Solstice , Multiply by remove and , Summer Solstice , Multiply by remove and , 3divide remove crossing ,. Winter Solstice,,. NearSummer Solstice,, yielding fixed. Then gen adds kun; xun subtracts qian from the fixed remainder. ,,, 1, alsoyielding fixed. ,, eclipseremainder. Chronogram divisor, eclipse. ,, 1,. Ifeclipse, entering qi, eclipse, eclipse,.
399
Method for computing the chronogram of lunar eclipse:
400
退
Three days obstruct—reduce the full-moon fixed remainder by half. Full moon entering qi, , new moon day divisormultiply , 1, obtain eclipse remainder and Multiply by , Multiply by obtain subtract new moon day divisor, eclipse remainder and Multiply by , as eclipse. Itseclipse1,. , eclipse, eclipse,, 12.
401
Method for computing beginning and ending chronograms of solar and lunar eclipses:
402
Eclipsefraction15, or below. 14, 1, 5fraction. 1fraction, 2,, by through 3fraction. Each accumulation adds 4. 4, 6, 19,. ,, day divisor, 1,. , day divisor, eclipseremainder,,,.
403
To find chronogram divisor:eclipse,,. Obscuration, 1.
404
Method for computing the initial point of solar and lunar eclipses:
405
西西 西 西西西 西 西西 西 西 西 西西
,,, obscuration. Due east: the moon descends obliquely north from above the sun. Before the southeast corner, viewing east: initially oblique—the moon high, sun below. Then the moon shifts slightly northwest, the sun gradually southeast; past the corner viewing south, the moon more north, sun skewed southwest. By through,,,. After the southwest corner, viewing west: moon northeast, sun southwest. , obscuration,,. Ifeclipse12, obscurationleft. , obscuration,. ,, obscuration. ,, obscuration. After the wu hour it gradually passes below from the side. ,, obscuration. ,, obscuration. , or below.
406
西 西西 西 西
,,, obscuration. Due east: the moon reflects obliquely south from below the sun. North of the corner: moon slightly southeast, sun returns west. ,, by through,,,,. North of the corner: moon southwest, sun again northeast. Due west: the moon rises obliquely south from below the sun. Obscuration,,. Eclipse, obscurationbegin,, eclipseoutside and inside, retrogradedirect,.
407
Five planets:
408
The year star is Wood (Jupiter).
409
Mars.
410
The queller star is Earth (Saturn).
411
Venus.
412
The chronogram star is Water (Mercury).
413
Wood number (Jupiter): 8605468.
414
Disappearance, 836848.
415
Return day: 398. Remainder: 41,156.
416
1,, 33. Remainder: NaN.
417
, 14degree.
418
滿
Mean appearance, atSpring Equinox, Start of Spring. Lesser Fullness, Spring Equinox, Spring Equinox. White Dewafter, Cold Dew. Lesser Heat, add7day. Lesser Snow, Cold Dew. Winter Solsticeafter, Start of Spring,, Lesser SnowWinter Solstice.
419
退退
, daily motion 1,818, daily decreasing slow 70, 10daily motion 18 and 40,738then stationary. 28then retrograde , retrograde 6,436, 87retrograde 12 and 204. Also stationary 28 days. Initial daily motion 4,188 fractions, increasing by 70 per day; in 110 days travels 18° 40,738 fractions, then disappears.
420
Fire number (Mars): 36377595.
421
Disappearance, 3379327.
422
Return day: 779. Remainder: 41,919.
423
,, 49. Remainder, 6.
424
, 16degree.
425
滿
Mean appearance, atRain Water, Great Cold:Pure Brightness, Rain Water, Rain Water. Summer Solsticeafter, End of Heat. Lesser Fullnesslater, also15day. Cold Dew, White Dew. Lesser Snow, Cold Dew, Cold Dew. Great Snowafter, Great Cold,, Lesser SnowGreat Snow.
426
, at Winter Solstice, then 236 daily motion 58°, °its each 1; 30day, 11. Also86day, 21. 38day,. Also15day, 31. 12day,. Also39day, 31. Also24day, 21. Also58day, 11. 33day,. Also 30, 1, through Winter Solstice, 236 daily motion 58°. ItsStart of SpringSpring Equinox, Summer SolsticeStart of Summer,. Spring Equinox through Start of Summer, subtract6day. Start of AutumnAutumn Equinox,, initial motion. White DewCold Dew, daily motion, daily motion. Multiply by , , , daily decreasing slow 20, slow , daily motion 22,669, daily decreasing slow 110, 61daily motion 25 and 5,409. Subtract , add 3,823 and bamboo tally 17. Slow motionas , its Slow motion daily motion 30°, fractions the same, then stationary13.
427
退退
Subtract day fraction2stationary , then retrograde , retrograde 2,526, 63retrograde 16 and 42,834. Stationary 13, 6,069, daily increasing fast 10, 61daily motion 25 and 5,409. Start of AutumnAutumn Equinox, 5, day fraction,. At winter solstice, in 213 days travels 135°; 36day, 11. Also20day, 21. 24day,. Also54day, 31. Also12day, 21. Also42day, 11. Also14day, 11. Also12day, 1. 45day,. Also106day, 21, Winter Solstice213day, motion35degree.
428
5, 5degree, asfast motion. ItsStart of SummerSummer Solstice, daily motion, daily motion. Summer SolsticeStart of Autumn, daily motion, daily motion. ,, daily increasing fast, then disappears.
429
Earth number (Saturn): 7635594.
430
Disappearance, 864995.
431
Return day: 378. Remainder: 4,162.
432
1,, 12. Remainder: NaN.
433
, 16.
434
滿 滿
Mean appearance, atGreat Heat, Lesser Fullness. Cold Dewafter, Lesser Snow,, Great HeatCold Dew. Lesser Cold, Lesser Snow. Rain Waterafter, Lesser Fullness. Start of Springafter, Rain Water, Rain Water,, Lesser ColdStart of Spring.
435
退退
, daily motion 4,364, 80daily motion 7 and 22,612then stationary 39then retrograde , retrograde 2,820, 3retrograde 6 and 596. Stationary 39, 4,364, 80daily motion 7 and disappearance.
436
Metal number (Venus): 27236208.
437
Disappearance, 957104.
438
Return day: 583. Remainder: 42,756.
439
1,, 218. Remainder: NaN.
440
Evening appearance and disappearance: 256 days。.
441
Morning appearance and disappearance: 327 days. The remainder is the same as before.
442
, 11degree.
443
Mean appearance, atStart of Autumn, Grain in Ear. Autumn Equinoxafter, Lesser Snow. Lesser Snowafter, Great Snow, Lesser Snow,, Start of AutumnAutumn Equinox. Start of Spring, Great Snow. Rain Water, Start of Spring, Start of Spring. Pure Brightnessafter, Grain in Ear,, Rain WaterPure Brightness.
444
Mean appearance, atLesser Cold, Winter Solstice. Start of Spring, Lesser Cold, Lesser Cold. Grain in Ear, Summer Solstice. Start of Summer, Grain in Ear, Grain in Ear,, Start of SpringStart of Summer. Lesser Heat, Summer Solstice. Start of Autumn, Lesser Heat. Lesser Heat. Great Snowafter, Winter Solstice. Start of Winterafter, Great Snow, Great Snow,, Start of AutumnStart of Winter.
445
滿 滿
Evening appearance, 71 daily motion 206°. From Grain Rain through Lesser Fullness and White Dew through Cold Dew, add 1° every 10 days; Lesser Fullness through White Dew, add3degree. Then in 12 days travel 12°. Winter Solsticeafter, 1, Rain WaterSummer Solstice, 7. Six days after summer solstice, increase by 1. Great HeatStart of Autumn, 12. Cold Dew, 22, 1. Great SnowWinter Solstice, 12slow motion. Daily increasing fast 520, daily motion 23,791 and bamboo tally 35, as , 43daily motion 32.
446
退退 退退
When prior entries add degrees, subtract accordingly. Stationary9 then retrograde , °, 6°, and evening disappearancemorning appearance. , 96degree. Stationary , 9, daily decreasing slow 520, daily motion 45,631 and bamboo tally 35, 43daily motion 32. Grain in EarLesser Heat, Great SnowStart of Winter,. Lesser Heat through Start of Winter, subtract2degree. Also in 12 days travel 12°. Winter Solsticeafter, 1. Awakening of InsectsSpring Equinox, 17, 1, Summer Solstice, 12. 1, White Dew,. Frost Descentafter, 1, Winter Solstice, 12. Fast motion, 71 daily motion 206°. ,, disappearance.
447
Water number (Mercury): 5405006.
448
Disappearance, 790099.
449
Return day: 15. Remainder: 40,946.
450
Evening appearance and disappearance: 51 days。.
451
Morning appearance and disappearance: 64 days. The remainder is the same as before.
452
, 17degree.
453
, atStart of AutumnlaterLesser Snow. Before White Dew and after Start of Summer, it sometimes appears.
454
滿
, atStart of SpringlaterLesser Fullness. Before Awakening of Insects and after Start of Winter, it sometimes appears.
455
Evening appearance, daily motion 1°, 12 daily motion 20°. Lesser HeatWhite Dew,, 12 daily motion, then8 daily motion. Great Heatafter, 1,,. And Slow motion, daily motion °, 4 daily motion 2°. Slow motion, daily motion °, 3 daily motion 1°. , slow motion. Stationary4 and evening disappearancemorning appearance, stationary4, as daily motion °, 3 daily motion 1°. Great ColdAwakening of Insects,,, daily motion. In 4 days travel 2°; Also in 8 days travel 8°. AlsoGreat Coldafter, 1. 16day,. Fast motion, daily motion 1°, 12 daily motion 20°. ,, 12 daily motion.
456
Method for computing mean appearance.
457
滿滿 滿 滿
Disappearance, remove. Subtract, when full day divisoras , not when full as , then the year soughtcelestial first monthWinter Solsticelater mean appearance. When Venus and Mercury fill the morning appearance-disappearance period, remove it—morning mean appearance. Mean appearance:Multiply by Winter Solstice remove new moon and remainder , add remainder , when full remove , , new moon divide , beyond tally,. To find later mean appearance: from prior appearance remove one or two year cycles and add remaining days. For return days, Venus and Mercury use morning/evening appearance-disappearance days; adding morning yields evening, adding evening yields morning.
458
滿
To find :,. When full,,. , add subtract mean appearance and remainder , as remainder.
459
To find fixed appearanceday:,, fixed appearance.
460
To find the degree where the star appears:
461
宿宿
Fixed appearance and half , Multiply by remainder , add and subtract day divisor, multiply fixed appearanceremainder , day divisorobtain add half , Multiply by first appearanceremove , subtract add , first appearance.
462
To find the next day:
463
滿退 滿 滿
Add each day's motion in degrees and fractions. For auxiliary fast or slow phases, set aside one day's motion fraction; increase for fast or decrease for slow by that fraction, then add. , when full divisorcarry to fraction,,. Stationarythen , retrogradethen subtractremove parts, retrograde. All divide by the bamboo-tally divisor to obtain rotation fraction. Remainders are still called bamboo tallies—each gives the daily position and distance from the sun. Increase by the daily entry prior-later fraction to obtain the fixed value. For all planetary degrees, find Mercury's inner and outer limits and step along the yellow path using lunar increase-decrease; When not visible, find solar distance by the ecliptic. Advance-retreat fractions likewise add before and subtract after the fraction. For Venus and Mars day-degrees, compute increase-decrease counts to obtain fixed values. ,,, alldegree divisor, 1,. When full bamboo tally , Multiply by as. ,, uniform motion. , subtract 1, half fast and slow multiply , fast Multiply by subtract and slow Multiply by add 1,. ,, day divisorifdegree divisor,,,. Incomplete values are also called bamboo tallies. Jupiter and Mars and Saturn , disappearance. Venus and Mercury at evening appearance return to evening disappearance; morning appearance means morning disappearance. Thereof initial motion Fast motion, Winter Solstice°, all carry to Winter Solstice, , its remove Winter Solstice, first appearanceFast motionremove Winter Solstice and thereof , and its that which ° thereof .
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