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卷二十九 志第九: 音樂二

Volume 29 Treatises 9: Music 2

Chapter 33 of 舊唐書 · Old Book of Tang
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1
Treatise 13: Calendars, Part Two
2
○ The Origin Calendar of the Linde jiazi Era
3
From the Superior Origin in the jiazi year to the present jiazi year of Great Tang, the elapsed years total 269,880 counts. Computation divisor: 1,340. True period value: 489,428. Ten-day cycle: 60.
4
○ Procedure for calculating the order of the solar terms
5
滿滿
Enter the jiazi-era accumulated count; compute the years from the present back to the year sought; multiply by the period constant to obtain the period total. When it fills the divisor, that counts as one accumulated day; the remainder is the small remainder. Strip out full ten-day cycles from the accumulated days; what remains is the large remainder. Starting from the large remainder, count from jiazi outside the reckoning—that gives the mean day of the winter solstice at the celestial first month for the year sought, with its large and small remainders. The celestial first month is established in the zi month; the pitch-pipes and solar terms take their origin from it—so the waxing and waning of yin and yang all begin from this point.
6
○ Procedure for finding the mean successive solar terms
7
滿 滿 滿
Take the winter solstice large and small remainders; add 15 to the large remainder, 292 to the small remainder, and five-sixths of a minor fraction. When minor fractions fill their unit, carry into the small remainder. When the small remainder fills the common divisor, carry one to the large remainder. When the large remainder fills the ten-day cycle, discard the cycle. Continue adding in sequence and assigning stem-branch names in turn—each step yields the term sought. All other cases follow this pattern. In general, the large remainder in a qi or new-moon remainder is the day, and the small remainder is the double-hour.
8
○ Finding the intercalary Earth days
9
滿 滿 滿
Take the small remainders for Pure Brightness, Minor Heat, Cold Dew, Minor Cold, and Great Cold; to each add 12 to the large remainder, 244 to the small remainder, and eight minor fractions. Cross-multiply the solar-term minor fractions to a common denominator and add eight. If the total reaches thirty, discard thirty and carry one to the small remainder. Whenever fractional remainders to be combined have different denominators, cross-multiply and combine them. Multiply the denominators together to form the divisor. When the combined numerator fills the divisor, that counts as one whole—this is the method of reduction to a common denominator. When the small remainder fills the common divisor, carry into the stem-branch name as before—each yields the intercalary Earth day following that solar term.
10
Buried-day divisor: 1,757.
11
Buried-day fraction: 122,357.
12
Procedure for finding buried days
13
滿
Multiply the small remainder of the qi that has a buried day by 90; multiply its minor fraction by 15 and add; subtract the sum from the buried-day fraction; divide the remainder by the divisor to obtain one day. The remainder is what is left; add the day-count to that qi's large remainder. Discard cycles and assign names as before—the buried day falls within that solar term. When a minor solar term's remainder is 1,040 or greater, do not compute a buried day for that term. When the buried remainders are fully exhausted, subtract. To find the next buried day: from the previous buried day add 69 days with remainder 1,104; when the remainder fills the divisor, carry one buried day and assign names in turn, distinguishing days by solar term.
14
Excess new-moon constant: 39,933.
15
Deficiency new-moon constant: 39,220.
16
Mean new-moon constant: 39,571.
17
Deriving the new-moon epoch
18
滿 滿滿 退 退宿宿
Set out the period total; divide by the mean new-moon constant to obtain accumulated months; the remainder is the intercalary remainder. When it fills the common divisor, that is one intercalary day; the remainder is the intercalary double-hour. Subtract the intercalary day from the winter solstice large remainder and the intercalary double-hour from the small remainder—that gives the large and small remainders for the mean new moon of the celestial first month for the year sought. From the large remainder, count from jiazi outside the reckoning—that is the day. The celestial first month is the month in which the sun reaches its southern limit. The mean new moon is the standard interval neither shortened nor lengthened. In general when subtracting, if the small remainder is insufficient, borrow one from the large remainder and subtract a full common divisor. When the large remainder is insufficient, add a full ten-day cycle and then subtract. When fractional subtraction is required, borrow one from the fractional remainder and subtract according to its divisor; when the wandering constant in lodge-degrees is insufficient, add the full lodge-wandering cycle with remainder and odd part, then subtract. Add the intercalary remainder to the celestial first-month mean new-moon small remainder and subtract from the period total—the remainder is the total constant.
19
Procedure for finding the mean first quarter, full moon, and last quarter
20
滿
From the celestial first-month mean new-moon large and small remainders, add 10 to the large remainder and 512 plus a major fraction to the small remainder—of four parts, one is minor, two is half, three is major. When it fills the divisor, discard the cycle and assign names as before—that gives the mean day of the first quarter for the celestial first month, with large and small remainders. Continue adding in sequence to obtain the full moon, last quarter, and the next month's new moon. Continue adding, discarding cycles and assigning names as before—together these yield the date sought. All other cases follow this pattern. To derive the full moon directly from the new moon: add 14 to the large remainder and 125 plus a half fraction to the small remainder. To derive the last quarter directly from the new moon: add 22 to the large remainder and 198 plus a minor fraction to the small remainder. To derive the next new moon directly from the new moon: add 29 to the large remainder and 711 to the small remainder. Half common divisor: 670. Double-hour rate: 335.
21
Procedure for verifying pitch-pipe response days and the added double-hour
22
Procedure for finding the provisional difference in gnomon shadow on the first day of a mean solar term
23
Take the ascending or descending rate of the term sought and of the following term; average them and divide by fifteen—this is the provisional terminal rate. Also subtract the two rates; divide the difference by fifteen—this is the total difference. If the earlier rate is smaller, subtract the total difference from the provisional terminal rate; if the earlier rate is larger, add the total difference to the provisional terminal rate. When adjustment of the provisional terminal rate is complete, the result is the provisional initial rate. When the following solar term has no corresponding rate, the preceding terminal rate serves as the provisional initial rate. Subtract the total difference from the initial rate; the remainder is the provisional terminal rate.
24
Procedure for finding the fixed difference in gnomon shadow on the first day of a mean solar term
25
Divide the total difference by fifteen—the quotient is the interval difference used as the limit. If the earlier rate is smaller, add the interval difference to the provisional initial and terminal rates; if the earlier rate is larger, subtract the interval difference from the provisional initial and terminal rates. When adjustment is complete, these are the fixed initial and terminal rates—the fixed shadow difference for the first day of the mean solar term.
26
Procedure for finding the next day's shadow difference
27
Using the separate fixed difference: if the earlier rate is smaller, add it to the first-day fixed shadow difference; if larger, subtract it. When this adjustment is complete, the result is the next day's fixed shadow difference. Accumulate day by day in sequence—each step yields the value sought. Each solar term spans a limit of fifteen days. Cases that use division by sixteen instead to obtain the provisional terminal rate and the total and separate differences.
28
Procedure for finding the fixed midday gnomon shadow for a mean solar term
29
Set the small remainder of that mean solar term; subtract half the common divisor—the remainder is the post-midday fraction. When it cannot be subtracted, subtract from half the common divisor instead—the remainder is the pre-midday fraction. Set the pre- and post-midday fractions; multiply by the fixed shadow difference and divide by the common divisor—the quotient is the variable difference. After the winter solstice, before noon subtract the variable difference from the term's shadow; after noon add it. After the summer solstice, before noon add the variable difference; after noon subtract it. On the winter solstice day there is only subtraction, never addition. On the summer solstice day there is only addition, never subtraction. When adjustment is complete, each term has its fixed midday gnomon shadow.
30
Procedure for finding the next day's midday shadow
31
仿
Step by step, add or subtract the fixed difference according to whether the rate ascends or descends from the mean term's fixed midday shadow—each step yields the next day's midday shadow. In the calendars of Later Han and of Wei and Song, the winter solstice midday shadow was twelve feet and the summer solstice shadow one foot five inches—both are shorter than present-day measurements. Each calendar must adjust its ascending and descending rates against shadows measured at the proper season, so that the midday shadow at each term matches the solstice rates. All other cases follow this model. The earlier procedure for finding each day's midday shadow—no ancient calendar had it; we, your ministers, devised this method anew.
32
Procedure for finding the days when pitch-pipes respond and the added double-hour
33
Each of the twelve pitch-pipes corresponds to the added double-hour of its month's mean central solar term; set out that term's small remainder, multiply by six, and divide by the double-hour rate—the quotient counts half common divisors; the remainder is the double-hour remainder. From the double-hour, begin counting from zi at the half-interval—that is the double-hour of the added moment. Multiply the double-hour remainder by six; when it fills the divisor, one counts as initial, two as minor-weak, three as minor, four as minor-strong, five as half-weak. If the moment falls after the middle of the double-hour, one counts as half-strong, two as major-weak, three as major, four as major-strong, five as the end of the double-hour.
34
Procedure for finding the seventy-two pentads
35
滿 滿
The mean solar-term day is the day of the first pentad. Add 5 to its large remainder, 97 to the small remainder, and 11 to the minor fraction. Multiply the solar term's minor fraction by three and add 11; when the total reaches 18, carry one to the small remainder. When it fills the divisor, discard the cycle and assign names as before—that gives the next pentad day. Continue adding in sequence to obtain the day of the final pentad.
36
Procedure for finding the next solar-term day and verifying excess and deficiency
37
退
Advance guideline: 16; retreat cycle: 17
38
General difference: 11; total double-hours: 12; sixty combined with mean shortfall
39
退 退
After the autumn equinox and before the spring equinox the sun's daily motion is fast; after the spring equinox and before the autumn equinox it is slow. Fast motion is advance guideline; slow motion is retreat cycle. When taking their numbers, the guideline serves as the name; when applying their seasons, the spring equinox marks the turning point. Advance before the day-fraction; retreat after the day-fraction. In general, all uses of guidelines and cycles follow this pattern.
40
調使
Take the lodge-difference rate of the term in question and of the following term; average them, multiply by the total double-hours, and divide by guideline and cycle—this yields the term's terminal rate. Each applies the general difference through its guideline and cycle to align the double-hour differences. Also subtract the two rates; multiply the difference by the total double-hours and divide by the cycle—this is the total difference. Divide by the double-hour guideline and cycle—this is the separate difference rate. If the earlier rate is smaller, subtract the total difference from the terminal rate; if the earlier rate is larger, add the total difference to the terminal rate. When adjustment is complete, each is the gain-loss rate for the first day of that solar term. If the earlier rate is larger, subtract the separate difference rate; if the earlier rate is smaller, add the separate difference rate. When the solar term's first-day gain-loss rate has been adjusted, the result is the next day's gain-loss rate. This is also called the daily lodge-difference rate. Continue adding and subtracting in sequence to obtain the value for each day. Accumulate the gains and losses; following the mean solar terms, the running total of gain-loss messages for each day is that day's message number. When the following term has no matching rate, or when rates coincide, if the earlier rate is smaller take the preceding terminal rate as the initial rate, add the total difference for the terminal rate, and gradually add the separate difference to the initial rate to obtain the daily rate. If the earlier rate is larger, subtract the total difference from the initial rate to obtain the terminal rate; gradually subtract the separate difference to obtain the daily rate. When a term's initial and terminal reckonings do not match what the guideline and cycle require, adjust gains and losses until the junctions align.
41
Procedure for finding the day and double-hour entered by solar-term excess and deficiency
42
滿退
For the winter and summer solstices, take the mean solar term as definitive. For all other terms, take the message number below the term; where it indicates rest, subtract, and where it indicates motion, add to the mean solar term's small remainder; when full or insufficient, advance or retreat the day. That gives the true day and double-hour of the solar term. Also determine its day and assign stem-branch names from jiazi to obtain the date sought. Addition yields an excess term; subtraction yields a deficient term—fix where the excess or deficiency falls, and the day is thereby determined. In general, when computing solar and lunar positions and when computing waxing and waning, all calculations rely on true solar terms. If annotating the calendar, use mean solar-term days.
43
Procedure for finding double-hours after midnight for true solar terms, true new moons, and true quarters and full moons
44
Set each small remainder; multiply by three; divide by the double-hour rate—the quotient is the number of double-hours after midnight.
45
Procedure for finding the daily accumulated excess and deficiency
46
Set each term's early and late rates with its excess-deficiency accumulation; then add the lodge-difference rate to the early and late rates and add the message total to the excess-deficiency accumulation, using the same method as for messages—this yields the daily entered excess-deficiency and early-late numbers.
47
Procedure for finding the mean entered excess and contraction numbers for new moon, first quarter, full moon, and last quarter on mean days
48
滿退
For each, multiply the entered true solar-term day by the total double-hours and compute the double-hours after midnight for new moon, first quarter, full moon, and last quarter; then subtract the entered true solar term's double-hours after midnight—the remainder is the double-hour total. When a mean new moon or quarter falls on the same day as a true solar term but with more double-hours, the new moon or quarter lies at the end of the preceding term; when the double-hour total exceeds the advance guideline and cycle common number, it may enter the beginning of the following term. Multiply the terminal rate if the earlier rate is larger, or the initial rate if the earlier rate is smaller; divide by the total double-hours—the quotient is the total rate. Whenever multiplication involves fractional remainders, reduce to a common denominator, multiply the numerators, then report to the denominator; when denominators differ, reduce them to a common measure. If the earlier rate is larger, subtract the cycle-multiplied total difference from the double-hour total; divide by guideline and cycle—the quotient is the difference. Add to the total-rate difference; multiply by the double-hour total; divide by twice the total double-hours; add to the total rate. If the earlier rate is smaller, multiply the double-hour total again by the separate difference, multiply by the total double-hours from the double-hour itself, double and divide; add to the total rate—these are all total numbers. Then apply later-addition and earlier-subtraction to the term's excess-deficiency to obtain the fixed accumulation; whenever fractional remainders do not form wholes and need not be continued, if more than half, do not carry to the following night without a term. With the excess-deficiency fixed accumulation, add for excess and subtract for deficiency from the day's small remainder; when full or insufficient, advance or retreat—each yields the entered excess-deficiency day and small remainder. If not a new moon or full moon with an eclipse and one wants a rough quick reckoning, multiply the entered true solar-term day by the early-late rate, add, and divide by fifteen—first add or subtract excess-deficiency for the fixed accumulation. For days entering a term counted as fifteen, add and divide by sixteen.
49
Calendar change cycle: 443,077.
50
Change odd rate: 12.
51
Calendar change day: 27; change remainder, 743; change odd, 1.
52
Lunar circuit divisor: 63.
53
Procedure for deriving calendar change
54
滿 滿 滿滿
Remove the calendar change cycle from the total constant; multiply the remainder by the change odd rate; when it fills the change cycle, remove again. What does not fill is reduced by the change odd rate to a change fraction. What is not exhausted is the change odd. When the fraction fills the common divisor, that counts as one day; the remainder is what does not fill. Count days outside the reckoning—that gives the change day and remainder entered at midnight of the celestial first-month mean new moon for the year sought; add the celestial first-month mean new-moon small remainder—that is the lodge entered.
55
Finding the lodge entered at new moon, first quarter, full moon, and last quarter
56
滿 滿 仿
From the celestial first month's lodge day, remainder, and odd entered at midnight, add 7 days, remainder 512, and odd 9. When the odd fills the rate, it becomes remainder. For the remainder: when it matches the common divisor, that counts as one day—this yields the lodge entered at the first quarter. Continue adding in sequence to obtain the full moon, last quarter, and the next month's new moon. When the entered value fills the change day, remainder, and odd, discard them. All successive removals follow this pattern. To derive the full moon directly, add to the new moon's entered day 14, remainder 1,025, and odd 6. To derive the next new moon directly, add one day, remainder 1,307, and odd 11.
57
Procedure for finding the entered day and double-hour of new moon, full moon, and quarters with excess-deficiency adjustment
58
Each takes that day's entered excess-deficiency fixed accumulation; add for excess and subtract for deficiency from the mean lodge entered—the remainder is the value sought for each.
59
Procedure for finding the fixed change slow-fast number for the entered day and double-hour of new moon, quarters, and full moon with excess-deficiency
60
退
List each entered day's increase-decrease rate; add it to the following rate and halve—the result is the common rate. Also subtract the two rates—the difference is the rate difference. For increase, subtract the entered remainder from the common divisor; multiply the remainder by the rate difference; divide by the common divisor and halve together with the rate difference. For decrease, halve the entered remainder multiplied by the rate difference, also divide by the common divisor and add to the common rate; multiply the entered remainder and divide by the common divisor—the result is lodge change at the turn and half lodge change at the turn. Fast subtracts and slow adds to the excess-deficiency lodge entered remainder—this is the turn remainder. Where increase is required, subtract from the divisor. Where decrease is required, use the remainder. In all cases multiply by the rate difference, divide by the common divisor, and add to the common rate. Multiply by the change rate and divide by the common divisor; subtract fast and add slow to the change rate to obtain the fixed rate. Then use the fixed rate to increase or decrease the slow-fast accumulation to obtain the fixed value. This method is minute and exact throughout, showing the thoroughfare of computational principle. If not a new moon or full moon with an eclipse and one wishes to examine or verify quickly, simply multiply the entered remainder by the increase-decrease rate, divide by the common divisor, and adjust slow—that suffices. When the following term has no matching rate, also follow the preceding rate; where increase is required, take the common rate as the initial number and subtract half the rate difference; where decrease requires advancing or retreating the day from the entered remainder, split into two days and compute according to whether the remainder is initial or terminal. Add or subtract the results to the change rate to obtain the fixed value.
61
For the entered remainder on the preceding item's day, if below the initial number it is initial; if above, subtract the initial number from the common divisor—the remainder is the terminal number. Increase and decrease are opposite; approximate with nine-ninths as the limit. Though the initial value is slightly weak and the terminal slightly strong, the remainders are nearly equal—reason suggests taking both, yet now there are mixed differences, each following its number. If by mean calculation one seeks, on the seventh and twenty-first days one obtains the initial rate, while what the terminal subtracts remains hidden and not displayed. Moreover, the numbers used in parallel regular calculation also have initial and terminal values, which mean calculation does not provide. On the fourteenth and twenty-eighth days, since initial and terminal numbers remain, the spurious difference also reduces those numbers—the numbers should be dropped from the mean divisor and not appear.
62
Procedure for finding the entered day name and small remainder of excess-deficiency for new moon, quarters, and full moon
63
滿退
Each takes the fixed change slow-fast number of the entered change cycle—fast subtracts and slow adds to its excess-deficiency small remainder. When full or insufficient, advance or retreat the day. Assign from jiazi beyond the count; for each, take the reversed remainder of the excess-deficiency day. Add to its mean day—the remainder is excess; Subtract its mean day—the remainder is deficiency. Where the day does not move, fix the small remainder according to the mean new-moon day and derive the solar and lunar motions in degrees. When the fixed small remainder is twenty-four or below, or thirteen hundred sixteen or above, the entered-qi excess-deficiency and entered-cycle slow-fast all require recalculation by the original procedure—they must not follow the rough shortcut for speed. Then compare the preceding new moon with the following new moon in turn. The reckoning of excess and deficiency takes actuality as the standard. Reduction must not encroach on deficiency; increase must not exceed excess.
64
Procedure for finding whether the month of the fixed new moon is long or short
65
In general the day name of the new-moon excess-deficiency is the fixed new-moon day name. For the fixed new-moon day name, if the ten stem matches the coming month the month is long; if not, it is short. A month without mid-qi is an intercalary month. When the first-month new moon has a fixed addition falling in first month, adjust one or two months before and after to determine whether the month is long or short. When conjunction and eclipse both fall on the last day of the month, the quarters and full moon are also adjusted as the case requires. In general when setting monthly new moons, the extreme of excess and deficiency does not exceed three in succession. If it exceeds this, observe whether the fixed small remainder is near midnight and measure accordingly.
66
宿
Procedure for checking lodge degrees
67
宿 宿退
The above twenty-eight lodges of the circuit of heaven, spaced at three hundred sixty-five degrees, were measured on the equatorial armillary sphere in Former Han and the Tang capitals. Their numbers are constantly fixed, girdling the center of heaven—the standard of armillary diagrams. Sun and Moon come and go, gaining and losing with the crossing. The lodge degrees entered differ in advance and retreat.
68
宿
The ecliptic lodge degrees—Left Palace Attendant Jia Da checked that the Sun and Moon's departure from the equator differs—were verified with a newly cast ecliptic armillary sphere.
69
調 退
We who compile and discuss here have newly made a wooden armillary diagram interlacing and balancing the yellow and red two paths at three hundred sixty-five odd degrees; measured at large rate, it agrees with this. The present calendar derives solar daily motion, lunar motion, and the ingress and egress of the five stars according to this. The Moon's motion crossing and interlacing the ecliptic should also differ in advance and retreat. At each crossing there is always difference—it cannot be detailed exhaustively. Now we also derive according to the ecliptic.
70
Procedure for deriving solar lodges
71
宿 宿宿滿宿宿
Set the winter-solstice first-day lodge-difference rate; add the common divisor; multiply by the winter-solstice small remainder; divide by the common divisor; subtract from the celestial lodge degree and fraction. With the remainder, assign beginning from Yellow Way Dipper twelve degrees; remove by lodge sequence; pass Dipper and remove lodge fraction and degree; outside the count when insufficient to fill a lodge—that is the lodge degree count and fraction where the winter solstice midnight of the year sought lies.
72
Procedure for finding the fixed degree where the Sun lies at midnight on the first day of each fixed qi
73
退宿退 退
Each takes that fixed qi's first-day lodge-difference rate, multiplies by the qi's fixed remainder, and divides by the common divisor; advance-add and retreat-subtract the remainder as parts; subtract from the fixed qi's solar degree and fraction; assign by lodge sequence as before—that is its midnight degree, and the fixed qi's first days of spring and autumn equinoxes are the start of advance and retreat, corresponding to one degree of uniform motion. For the rest, add degrees by advance and subtract by retreat.
74
Procedure for finding the fixed degree where the Sun lies at midnight on the next day
75
退 滿
Each takes the fixed-qi midnight position as base and adds one degree. Also with that day's lodge-difference rate, advance-add and retreat-subtract degree and fraction. When full or insufficient, all follow the preceding pattern. Remove and assign as above—then obtain what is sought. The midnight solar degrees for fixed new moon, quarters, and full moon each follow fixed qi; assign their day and month names directly and distinguish them. Examined at right: following the mean there is remainder; proceed from fixed-mean motion in degrees—do not use lodge difference.
76
Procedure for finding the solar degrees added at the fixed day and double-hour of new moon, quarters, and full moon
77
退
Each takes its fixed small remainder as the equal fraction. Also multiply the fixed small remainder by that day's lodge-difference rate and divide by the common divisor; then advance-add and retreat-subtract its equal fraction; add to its midnight solar degree—that is what each fixed double-hour adds. Where it adds and subtracts with the five stars, halve the fraction; where the monthly new moon is adjusted, what lunar motion requires—all follow the original new moon's long or short month. If annotating the calendar, assign entry according to jiazi and yichou respectively.
78
Procedure for deriving lunar separation
79
Procedure for finding the degree where the Moon lies at the fixed day and double-hour of new and full moon
80
Set the solar degree and fraction added at the fixed double-hour of each new moon, quarter, and full moon.
81
In general what the fixed new-moon double-hour adds is conjunction new moon—Sun and Moon at the same degree. First quarter: add ninety-one degrees, four hundred seventeen parts.
82
Full moon: add one hundred eighty-three degrees, eight hundred thirty-four parts.
83
退
Last quarter: add two hundred seventy-three degrees, one thousand two hundred fifty-one parts. When complete, halve each and retreat by ten—the result is cycle degree and parts.
84
Procedure for finding entry into the change cycle at midnight of the next month's fixed new moon
85
退退
Set the change day and remainder entered at midnight of the celestial first month's mean new moon. If the fixed new moon advances or retreats one day, advance or retreat one day for what is entered at fixed-new-moon midnight.
86
Long month adds two days; short month adds one day. Remainders are all five hundred ninety-six, with fraction sixteen.
87
Procedure for finding entry into the change cycle at the next day's midnight
88
滿
From the day count entered at fixed-new-moon midnight, add one day; when full, all as before. The quarters are all sought according to where the preceding fixed day lies.
89
Procedure for finding the fixed separation course for change days
90
退
Each multiplies that day's midnight entered change remainder by separation difference and divides by the common divisor—that is the visible difference. Advance-add and retreat-subtract to its daily separation course—that is the Moon's fixed daily separation course.
91
Procedure for finding the degree where the Moon lies at midnight on the fixed day of new moon, quarters, and full moon
92
滿 宿 滿宿 滿 滿
Each multiplies that day's fixed small remainder by the entered change day's fixed separation course and divides by the common divisor—that is the fraction after midnight. When it fills the course divisor it becomes degrees; the remainder is degree-parts. Subtract from the degree and fraction where that day's added double-hour lies; assign by ecliptic lodge degrees—that is what is sought. At the next day's midnight, add the fixed separation course to the fraction where new moon, quarters, and full moon lie at midnight; when it fills the course divisor carry to degrees; remove and assign by ecliptic lodge degree count outside—that is the Moon's degree at the next midnight. To find dawn and dusk degrees, multiply that day's fixed separation course by that day's day-and-night clepsydra marks and divide by two hundred—that is the dusk fraction; when it fills the course divisor it becomes degrees. Before full moon use dusk; after use dawn; add to midnight degrees—to obtain what is sought. For quarters and full moon, multiply the fixed small remainder by five and divide by course divisor one—that is clepsydra marks; that is the clepsydra-mark number entered for each double-hour. All subtract the marks before dawn; what remains is the marks after dawn. If insufficient for marks before dawn, follow the previous day's calendar annotation and wait to derive.
93
Total marks: one hundred. Double-hour marks: divide eleven. Clepsydra-mark fraction divisor: seventy-two.
94
Procedure for finding day-and-night clepsydra marks of fixed-qi days and sunrise and sunset
95
滿 滿
Double its qi's marks before dawn and fraction; when full carry from marks—that is the clepsydra of invisible sun. Subtract from one hundred marks; the remainder is the clepsydra of visible sun. Day clepsydra marks: five marks. Subtract day clepsydra marks from one hundred marks; the remainder is night clepsydra marks. Add four marks twelve parts to clepsydra marks before dawn; assign beginning from zi initial mark beyond the count—that is the double-hour mark of sunrise. Add visible-sun clepsydra to sunrise mark and double-hour; in order as before—that is the double-hour mark where the sun sets. Divide night clepsydra by twenty-five to obtain the count for each watch tally. Add two marks thirty-six parts to sunset double-hour mark—that is first-yin mark; also add watch-tally count to obtain the first watch tally of the night. Accumulate in order; when full remove by double-hour and assign—that is how the five watches' night tallies correspond to double-hour marks, matching the method of twenty-one-arrow clepsydra.
96
Procedure for finding daily combined flexion and extension numbers
97
滿滿 滿
Each qi is taken as fifteen days; set each qi's flexion-extension rate. Each uses waxing-waning difference to gain and lose; when difference fills ten carry to parts, when parts fill ten carry one to rate—that is each day's flexion-extension rate. Accumulate flexion-extension rates as clepsydra parts; then multiply clepsydra parts by one hundred eighty; multiply general difference by guideline and cycle and divide—to obtain clepsydra difference; when full of divisor it becomes marks. Following where the qi lies, subtract extension and add flexion to invisible clepsydra and halve—that is the fixed marks before dawn. Each time the next day is sought, all as the preceding method. Add time as at the beginning; as added double-hours make the day late, assess by rate.
98
Procedure for finding the daily difference of the ecliptic's departure from the pole
99
滿
Set the clepsydra difference; divide by thirty to obtain degrees. What does not fill thirty counts as fractional parts. Subtract extension and add flexion to that qi's initial ecliptic degree—that gives what is sought for each day.
100
Procedure for finding dusk and dawn departure from culmination-star degrees
101
宿 宿
Each day find its day clepsydra mark count; multiply by the period constant; divide by two hundred times the common divisor—to obtain the dusk departure from culmination-star degree. Subtract from the circuit-of-heaven degrees; the remainder is the dawn departure from culmination-star degree. Add the dusk and dawn departure from culmination-star degrees to where the double-hour day lies—that gives each noon lodge degree. For the rough outline method, add the midnight solar degree to obtain each noon star lodge degree.
102
To seek the next day, set each day's four-mark difference; multiply by seventy-two; two hundred eighty-eight make one degree. After the winter solstice add; after the summer solstice subtract. Add day by day; each step yields the daily departure from center degree. The dawn and dusk distance from the Sun at the ecliptic median-star standard degree is calculated by the equator. Its equatorial distances match those of the Taichu calendar.
103
Procedure for calculating wandering-node crossing
104
Terminal rate: 10,939,313. Odd rate: 300.
105
Reduced terminal: 36,464 odd 113.
106
Crossing center: 18,232 odd 56½.
107
Crossing middle days: 27 remainder 284 odd 113.
108
Middle day: 13 remainder 812 odd 56½.
109
Waning new moon: 316 odd 187.
110
True full moon: 19,785 odd 150.
111
Rear criterion: 152 odd 903½.
112
Front criterion: 16,678 odd 263.
113
Procedure for finding the Moon's entry into crossing outside and inside
114
滿 滿 退退 滿 滿 滿
Set the total constant; remove by the terminal rate. What does not suffice to remove, multiply by the odd rate. When it fills the terminal rate, remove again. What does not fill, reduce by the odd rate—that is the crossing-entry fraction at midnight of the celestial first-month mean new moon. What is not exhausted is the odd fraction. Reduce the crossing-entry fraction by the common divisor—that gives days. What is not exhausted is the remainder. Count days outside the reckoning—that gives the crossing-entry day count, remainder, and odd at midnight of the celestial first-month mean new moon. When the celestial first-month fixed new moon advances or retreats one day, advance or retreat one day for what the conjunction enters. When the day does not fill the middle day and remainder and odd, the Moon is outside; When full, remove; when the remainder is all one, the Moon is inside. Long month add two days; short month add one day; remainders are all 1,055 odd 187. To seek the next day, add one day; when full of the middle day remove all; the remainder is the next entry. One outside and one inside, entering alternately.
115
Procedure for finding the Moon's entry into crossing and its distance from the solar path
116
退 退滿滿 宿 退退
Set the entered day difference; combine with the rear difference and halve—that is the common rate. For advance: subtract the entered day remainder from the common divisor; multiply by the difference and divide by the common divisor; combine with the difference and halve. For retreat: halve the entered remainder; multiply by the difference and divide by the common divisor. In all cases add to the common rate—that is the crossing fixed rate. Then multiply the entered remainder by the fixed total divisor. Then apply the advance-and-retreat difference accumulation; when full of ten counts as degrees, what does not fill counts as parts—that gives each day's Sun and Moon departure from the solar path in degrees. Each time the solar-path lodge degree departure-from-pole number is sought: on entered day seven, when the remainder is 1,076 odd 28 minor or below, advance; when above, take entirely; When the remainder is 263 odd 271 major or greater, retreat and enter day fourteen; when like the crossing remainder odd or below, retreat; When the entered value is above, take entirely; When the remainder is 527 odd 242½, advance. In the end the essential value is five parts. Initially, seven days yield four parts and fourteen days yield three parts; Finally, after seven days one part and after fourteen days two parts. Though initially strong and finally weak, the difference rate has a check; when the lunar path is one and a half degrees strong or below, it is touching the ecliptic. At new and full moon, there is then eclipse waning. When the five planets lie on the ecliptic, mutual invasion and occultation then occur.
117
宿
Procedure for finding the lodge entered
118
滿宿 宿宿
Find the midnight crossing-entry day count of thirteen and its remainder; subtract from the middle day and remainder; multiply what is not exhausted by that day's fixed separation course and divide by the common divisor—that is the separation fraction; when full of the course counts as a degree; add to that day-and-night half-Moon lodge degree count and fraction; seek the next crossing likewise—each yields the fixed crossing lodge degree entered. Set the front and rear fixed crossing lodge degree count and fraction; halve—that gives each outside-and-inside pole lodge degree and fraction.
119
Finding the general crossing fraction field for mean new and full moon
120
滿
From the crossing-entry fraction at midnight of the celestial first-month mean new moon, use the celestial first-month mean new moon general crossing fraction to find the full-moon general crossing; add the true full moon. Add again to obtain the next month's mean new moon general crossing fraction. When full of the reduced terminal and odd, remove. Next seek the following new moon; add the waning full moon.
121
Procedure for finding new and full moon entry into regular crossing fraction
122
滿退
Use the entered-qi excess-deficiency fixed accumulation; excess adds and deficiency subtracts from the mean general crossing fraction; when full or insufficient, advance and retreat the reduced terminal. That is its regular crossing fraction.
123
Procedure for finding the fixed crossing fraction at new and full moon
124
Multiply the fixed slow-fast by sixty; reduce and divide by 777—the result is the limit number. Fast subtracts and slow adds as usual. When at new moon the Moon entering the crossing is inside the solar path, subtract the limit number entered from the fixed slow-fast; with the remainder, fast subtracts and slow adds to its fixed crossing fraction. When it exits outside the solar path, that is the changed crossing fraction. When addition and subtraction do not exit outside the solar path, follow the fixed crossing fraction to find the eclipse fraction. When the changed crossing fraction exits outside the solar path within three and a half double-hours, check the preceding and following month's full-moon crossing-entry fraction amounts; follow the lunar waning initial, restoration, and final fixed eclipse procedure; note waxing and waning—to determine whether there is an eclipse.
125
Procedure for finding entry into eclipse limit
126
When the crossing-entry fixed fraction is at the crossing center or below, the Moon is on the outer path; When above the crossing center, subtract the crossing center; the remainder is the Moon inside. When the fraction is at the rear criterion or below and the front criterion or above, that is entry into the eclipse limit. At full moon there is lunar eclipse; at new moon entering the limit, when the Moon is inside there is solar eclipse. When the entry into the limit is at the rear criterion or below, that is the post-crossing fraction; When at the front criterion or above, subtract inversely from the crossing center; the remainder is the pre-crossing fraction. Divide by 112—that gives the crossing double-hour.
127
Procedure for finding the double-hour where lunar eclipse lies
128
Set the full-moon day's invisible marks; multiply by sixty-seven and divide by ten—the result: if the eclipse full-moon fixed small remainder equals it or is below, also use this result to subtract from the common-divisor remainder and when equal or below, that is the eclipse true-visibility fixed small remainder. As in the procedure for finding the pitch-pipe qi response added double-hour, obtain the added double-hour where it lies; the Moon in the opposing double-hour at eclipse; if not true visibility, within twelve and a half marks after sunrise or before sunset seek the initial and final moments to await it. Also subtract the eclipse fixed small remainder by half the common divisor; when insufficient to subtract, add the half common divisor and subtract when done; multiply by six; divide by the double-hour rate; assign beginning from zi at the half-interval beyond the count—that is the double-hour where lunar eclipse lies.
129
Procedure for finding the double-hour where solar eclipse lies
130
退 滿 退
Set the eclipsing new-moon fixed small remainder aside; divide by the double-hour rate; take gen, kun, xun, qian in sequence; assign retreat beyond the count. When not full of the divisor, subtract half the divisor. When nothing can be subtracted, that is initial; The remainder after subtraction is final. If initial, subtract the divisor; each gives the difference rate. When the Moon is on the inner path, add ten to the distance-from-crossing double-hour count and divide by three; multiply by the difference rate and divide by fourteen—that is the difference. When the new moon falls within one qi before or after either equinox, use the difference as fixed. Near the winter solstice use the distance from Cold Dew and Rain Water; near the summer solstice use the distance from Clear and Bright and White Dew; multiply the qi count; also increase by three-tenths of the distance-from-crossing double-hour count. Near the winter solstice gen and xun add and kun and qian subtract; Near the summer solstice gen and xun subtract and kun and qian add to the difference—that is the fixed difference. Gen and kun add to the aside; xun and qian subtract from the aside. When the Moon is on the outer path, reduce the distance-from-crossing double-hour count by three-tenths; multiply by the difference rate and divide by fourteen—that is the difference. Gen and kun subtract from the aside and xun and qian add to the aside; when all additions and subtractions to the aside are done, that is the fixed aside small remainder. As in the procedure for finding the pitch-pipe qi response added double-hour, obtain the double-hour where the solar eclipse lies and its minor and major degree. To find the entry double-hour marks: multiply the new moon by half the double-hour marks, divide by the double-hour rate, and obtain marks and fractions. If the eclipse falls near dawn or dusk, use the new moon's entering qi sunrise and sunset marks to verify the eclipse position and determine how visible it will be; the double-hour where it lies is true visibility for a total solar or lunar eclipse; at emergence and restoration, initial and final moments may also deviate from the norm—retreat twelve and a half marks before or after visibility to await it.
131
Procedure for finding lunar emergence and restoration according to eclipse fraction, following the procedure above
132
Procedure for the criterion when a new moon with the Moon on the outer side of the sun's path should not eclipse When the new moon falls on the first day of summer solstice, the criterion is: a distance from the crossing before or after of 248 fractions is the initial criterion; below that, if the added double-hour falls within seven marks before or after noon culmination, there is an eclipse. For the new moon's distance from summer solstice before or after, each day reduce the initial criterion by two fractions; this completes at ninety-four days before or after, each becoming a daily variable criterion. When the new moon's distance from the crossing is at the variable criterion or below, and the added double-hour is as above, there is an eclipse.
133
Also subtract the initial and variable criterion by the final criterion of 60; divide the remainder by 18—that is the mark criterion. Take the combined count of seven marks before or after noon culmination as the time criterion. When the distance-from-crossing fraction is within the added double-hour criterion and at the final criterion or below, both conditions indicate eclipse. Also set the final criterion: each mark adds 18—that is the difference criterion. For each added double-hour mark: if the distance from noon before or after is at the difference-criterion marks or below, and the distance-from-crossing fraction is at the difference or below, both indicate eclipse. From autumn equinox to spring equinox: if the distance from the crossing is at the final criterion or below and the added double-hour falls in the three southern double-hours, there is also an eclipse. Whenever the fixed crossing fraction lies outside half a double-hour before or after the double-hour, even if it enters the eclipse criterion beforehand, that counts as eclipse. Procedure for the criterion when a new moon with the Moon on the inner side of the sun's path should eclipse but does not On summer solstice day at new moon: a distance from the crossing of 1,373 is the initial criterion; above that, if the added double-hour falls within eighteen marks before or after noon culmination, there may be no eclipse. For the new moon's distance from summer solstice before or after, each day increase the initial criterion by one and a half fractions; this completes at ninety-four days before or after, each becoming a daily variable criterion. Subtract the variable from the initial; divide the remainder by ten—that is the mark criterion. Subtract the marks from eighteen marks before or after noon culmination; divide the remainder by ten—that is the time criterion. When the distance from the crossing is above the variable criterion and the added double-hour falls within the criterion, there may be no eclipse.
134
Procedure for finding lunar eclipse fraction
135
Set the fixed distance-from-crossing before or after fraction; for winter crossing before or after, each subtract 224. In spring: after the crossing subtract 100; before the crossing subtract 200. In summer, regardless of before or after: subtract 50. In autumn: after the crossing subtract 200; before the crossing subtract 100. When insufficient to subtract, it is a total eclipse. When there is a remainder, subtract from the rear criterion and divide by 104. If the remainder is half the divisor or below, it is half-weak; if half the divisor or above, it is half-strong. Assign with fifteen as the limit to obtain the major lunar eclipse fraction.
136
Procedure for finding where lunar eclipse begins
137
西 西 西 西 西 西
When the Moon is on the inner path: in an eclipse of the eastern three double-hours, obscuration begins from below the moon slanting southward and upward; the moon moves from west gradually northward, from east gradually southward. In an eclipse of the southern three double-hours, obscuration begins at the lower left, reaches greatest at due south, and again at the lower right. In an eclipse of the western three double-hours: obscuration proceeds from south gradually eastward; the moon from north gradually westward; it begins above the moon, slanting southward and downward. When the Moon is on the outer path: in an eclipse of the eastern three double-hours, obscuration begins from below the moon slanting northward and upward; obscuration begins east gradually northward, the moon from west gradually southward. In an eclipse of the southern three double-hours, obscuration begins at the upper left, reaches greatest at due north, and again at the upper right. In an eclipse of the western three double-hours: obscuration proceeds from north gradually eastward; the moon from south gradually westward; it begins above the moon, slanting northward and upward. Whenever the eclipse is twelve parts or above, emergence and restoration all follow the ecliptic position; at due flank, reverse and direct, above and below—each passing its fraction. The path also has ascent and descent, each differing; each follows the time to take the due position.
138
Procedure for finding solar eclipse fraction
139
滿
When the Moon is on the inner path: from new moon entering winter solstice through waning Rain Water, and from waxing autumn equinox through Great Snow—all use 558 as the eclipse difference. From entering waning spring equinox onward, each day reduce six fractions until completed at White Dew. Set the eclipse distance-from-crossing before or after fixed fraction; subtract the eclipse difference from all. But when the distance-from-crossing fraction is insufficient to subtract, inversely subtract the eclipse difference as the non-eclipse remainder. From entering waning Minor Fullness through waxing Minor Heat, if the added double-hour falls outside seven marks before or after noon culmination, subtract one time from the non-eclipse remainder; within three marks, add one time to the non-eclipse remainder. From waning Great Cold through waning Start of Spring, outside five times before the crossing; from Great Heat through waxing Start of Winter, outside five times after the crossing—all subtract one time from the non-eclipse remainder; within five times add one time. For all added double-hour eclipse differences that should be subtracted: after the crossing subtract; before the crossing add. Those that should be added: after the crossing add; before the crossing subtract. But when insufficient to subtract, it is a total eclipse. When addition and subtraction enter the non-eclipse limit, there may be no eclipse. When the Moon is on the outer path: the winter solstice first day has no eclipse difference. From then on each day increase six fractions, accumulating as the eclipse difference until completed at waning Rain Water. From entering waning spring equinox through waxing White Dew—all use 522 as the eclipse difference. From entering waxing autumn equinox onward, each day reduce six fractions until completed at Great Snow. The remainder after reduction is the eclipse difference. Add the eclipse difference to the distance-from-crossing fixed fraction—that is the eclipse fraction. Subtract from the rear criterion; the remainder is the non-eclipse fraction. Set each new-moon eclipse difference; divide by fifteen; subtract from 104; the remainder is the fixed divisor. For the non-eclipse fraction remainder: each division by the fixed divisor obtains one part. If the remainder is half the divisor or above, it is half-strong; below, it is half-weak. Subtract fifteen; the remainder is the major eclipse fraction.
140
Procedure for finding where solar eclipse begins
141
西 西 西 西西 西 西 西 西 便
When the Sun is on the inner path: in a solar eclipse of the eastern three double-hours, obscuration begins from above the sun near north slanting downward; the moon moves gradually northwest, the sun gradually southeast. In a solar eclipse of the southern three double-hours, obscuration begins at the lower right, reaches greatest at due north, and again at the lower left. The moon is in the south gradually eastward; the sun in the north gradually westward. In a solar eclipse of the western three double-hours: the moon moves gradually northeast, the sun gradually southwest; obscuration begins from below the sun near west slanting upward. When the Sun is on the outer path: in a solar eclipse of the eastern three double-hours, obscuration begins from above the sun near south slanting downward; the moon moves gradually southeast, the sun gradually northwest. In a solar eclipse of the southern three double-hours, obscuration begins at the lower right, reaches greatest at due north, and again at the lower left. The moon is in the south gradually eastward; the sun in the north gradually westward. In a solar eclipse of the western three double-hours: the moon moves gradually southwest, the sun gradually northeast; obscuration begins from below the sun near south slanting upward. Whenever the eclipse is twelve parts or above, it begins at the due flank. Each follows the ecliptic's ascent and descent to gauge its disk. Following where each lies, all differ. Eclipses have initial and final moments; their movement spans its time; increase and decrease as needed to fix the direction of obscuration and restoration.
142
Procedure for finding the moments of eclipse waning initial and restoration final
143
Set the new and full moon eclipse major fraction count as the rate. Four parts or above: accordingly increase by two. Five parts or above: accordingly increase by three. Nine parts or above: accordingly increase by four. Thirteen parts or above: accordingly increase by five. Each becomes a general-use mark rate; set it aside. Multiply by the entered rate; set aside. Multiply by the entered change increase-decrease rate; divide by the common divisor; when fast, increase or decrease and subtract or add; when slow, follow its increase-decrease to the aside; when done, that is the fixed eclipse-use mark count. Then multiply by four and divide by ten; subtract from the maximum eclipse double-hour marks—that is waning initial. Also multiply by six and divide by ten; add to the maximum eclipse double-hour marks—that is restoration final. According to its fixed added double-hour position in double-hour marks, add and subtract to assign; each to its double-hour; the lunar eclipse maximum initial and final night-watch tallies. Following the sun and moon's entered double-hour marks and fractions, according to the prior fixed qi night-mark night-watch tally procedure, find the initial, final, and maximum night-watch tallies.
144
退
The Indian method of Kāśyapa Xiaowei and others: first according to the sun and moon's slow and fast degrees, derive the crossing-entry distance, eclipse fraction, and added double-hour; solar and lunar eclipses also use fifteen parts. At distances from the crossing of fifteen, fourteen, and thirteen degrees—the shadow-waning non-eclipse method applies; from here below, one then relies on verified eclipse. At twelve degrees fifteen parts—an eclipse of two parts minor-strong, gradually decreasing by difference; from five and a half degrees above—a total eclipse of fourteen parts strong. If five degrees with no remainder below, all is entirely eclipsed. Also use the magnitude of the prior eclipse to fix the fraction remainder of the next. If the eclipse was total, add seven degrees to its later eclipse degree and parts to obtain the eclipse degree. If a full-moon eclipse is total, the next month's new moon may enter the criterion yet is not registered as an eclipse. If the eclipse is half or less, take one part in five; if half or more, take one part in three and add it to the next month's new-moon eclipse degree and parts. Once the current year's solar remainder in degrees and parts is set, one may then verify the eclipse degree and fraction. It also states that, by the nodes, there is one eclipse every six months. The fifteenth of that month is the full-moon eclipse node; the dark of the moon is wholly the full-moon eclipse node. These omens of fortune and misfortune warn the king to uphold the righteous law: when the people are deeply blessed, though an eclipse is seasonally due, it retreats for that very blessing. Six months later, before an eclipse is due, there are always foretokens. When the moon is about to be eclipsed, its disk first trembles and shakes as if in alarm; the hare in the moon and the moon's limb turn yellow, as though stricken with grief. Apart from its usual halo, at first waxing the light does not blaze forth, or is exceedingly faint. When the sun is about to be eclipsed, its disk first trembles and shakes, as if in extreme alarm. Its light and color may grow faint and dim, no longer blazing bright, or turn dusky and grim. Solar and lunar eclipses share the same foretokens: light falls away; at dawn or dusk a red glow rises as if afire; gold, silver, pearls, jade, and every treasure lose their luster. Gaps may be eaten away as though clouds swallowed the sun, or blackness swallowed the moon; birds cry thinly and hidden, crows lose their brightness; clouds tangle in turmoil and light grows wholly confused; suddenly, to the extreme, the milk of all nursing creatures fails; the moon grows damp as with sweat; the sun's disk splits segment by segment and goes dark; dogs howl and cats wail; a rainbow appears with sound; the three luminaries lose their wholeness; the moon at times shows gaps; water turns red and greasy. On the fourteenth and fifteenth days, warblers gathering in circles are also a foretoken of eclipse. These differ slightly from China's numerical methods, yet in broad outline they are much the same.
145
Procedure for the Five Planets
146
Appearance-invisibility: 52 days; morning appearance-invisibility: 63 days; remainder and odd parts match the terminal fraction odd.
147
Procedure for Finding the Five Planets' Mean Appearances
148
退退 滿 滿
For each planet, subtract the invisibility fraction from the accumulated remainder and divide the remainder by that star's total cycle rate. If the division cannot be completed, subtract the remainder inversely from the total rate. Reduce the remainder by the total factor to obtain days; what remains undivided is the remainder odd—that gives the morning or evening mean appearance day count and remainder odd after midnight of the celestial first month's mean new moon for the year sought. When the celestial first month's fixed new moon advances or retreats a day, subtract a day for advance and add a day for retreat to obtain the mean appearance day and remainder odd after midnight of the fixed new moon. For Venus and Mercury, first obtain the evening mean appearance; cast out the full appearance-invisibility days and remainder; the remainder is the morning mean appearance day and remainder odd. From the appearance day, cast out full months according to the celestial first month calendar's long and short months; what does not fill a month is the month entered; count the day outside the reckoning—that gives the month, day, and remainder odd of the morning or evening mean appearance.
149
Procedure for Finding Later Mean Appearance Month and Day
150
滿 滿
For each planet, add that star's terminal day count and remainder odd to the prior mean appearance's month, day count, and remainder odd. When the odd parts fill the odd rate, carry into the remainder. When the remainder fills the total factor, convert it to days. Cast out and assign as before to obtain the later mean appearance's month, day, and remainder odd; for Venus and Mercury, adding the evening date yields the morning, and adding the morning yields the evening. Halve each planet's appearance remainder to match the half-total.
151
Procedure for Finding the Five Planets' Regular Appearances
152
滿滿
For each planet, according to the mean qi entered at its mean appearance, calculate the daily diminish-increase. When the parts fill the half-total, convert them to days; what does not fill remains as parts; apply the diminish-increase to add or subtract. When this is done, apply the remainder to add or subtract from the completed mean appearance day and parts—that yields the regular appearance day and parts. At first appearance, distance from the sun in degrees; mean appearance entering-qi calendar. Add-subtract days. Diminish-increase rates.
153
滿
Jupiter: at first appearance it stands fourteen degrees from the sun. At mean appearance entering the Winter Solstice through Minor Cold, uniformly subtract six days. From Major Cold onward, subtract 67 parts per day. At mean appearance entering the Spring Equinox on the first day, follow the mean rate. From then on, add 89 parts per day. From the Start of Summer through Minor Fullness, uniformly add six days. From Grain in Ear onward, subtract 89 parts per day. From the Summer Solstice through the Start of Autumn, uniformly add four days. From End of Heat onward, subtract 178 parts per day. At White Dew, follow the mean rate on the first day; from then on, subtract 52 parts per day. From Minor Snow through Major Snow, uniformly subtract six days.
154
Mars: at first appearance it stands seventeen degrees from the sun. At mean appearance entering the Winter Solstice, subtract 27 days on the first day. From then on, subtract 603 parts per day. At Major Cold, follow the mean rate on the first day. From then on, add 402 parts per day. From Rain Water through Grain Rain, uniformly add 27 days. From the Start of Summer onward, subtract 198 parts per day. At the Start of Autumn, follow the mean rate. From End of Heat onward, subtract 190 parts per day. From Minor Snow through Major Cold, uniformly subtract 27 days.
155
Saturn: at first appearance it stands seventeen degrees from the sun. At mean appearance entering the Winter Solstice, subtract four days on the first day. From then on, add 89 parts per day. From Major Cold through the Spring Equinox, uniformly subtract eight days. From Clear Brightness onward, subtract 59 parts per day. At Minor Heat, follow the mean rate on the first day. From then on, add 89 parts per day. At White Dew, add eight days on the first day. From then on, subtract 178 parts per day. At the Autumn Equinox, uniformly add four days. From Cold Dew onward, subtract 59 parts per day. At Minor Snow, follow the mean rate on the first day. From the mean rate onward, subtract 89 parts per day.
156
滿
Venus: at first appearance it stands eleven degrees from the sun. Evening appearance: from the Winter Solstice, follow the mean rate on the first day. From then on, subtract 100 parts per day. From Awakening of Insects through the Spring Equinox, uniformly subtract nine days. From Clear Brightness onward, subtract 100 parts per day. At Grain in Ear, follow the mean rate. From the Summer Solstice onward, add 100 parts per day. From End of Heat through the Autumn Equinox, uniformly add nine days. From Cold Dew onward, subtract 100 parts per day. At Major Snow, follow the mean rate. Morning appearance: from the Winter Solstice, follow the mean rate. From Minor Cold onward, add 67 parts per day. From the Start of Spring through the Start of Summer, uniformly add three days. From Minor Fullness onward, subtract 67 parts per day. At the Summer Solstice, follow the mean rate. From Minor Heat onward, subtract 67 parts per day. From the Start of Autumn through the Start of Winter, uniformly subtract three days. From Minor Snow onward, subtract 67 parts per day.
157
滿
Mercury: at first appearance it stands seventeen degrees from the sun. Evening appearance: from the Winter Solstice through Clear Brightness, follow the mean rate. From Grain Rain through Grain in Ear, uniformly subtract two days. From the Summer Solstice through Major Heat, follow the mean rate. From the Start of Autumn through Frost's Descent, it should appear but does not. If within the two qi of Start of Autumn and Frost's Descent, in the evening it stands more than eighteen degrees but less than thirty-six degrees from the sun, and Jupiter, Mars, Saturn, or Venus is also visible, it is seen as well. From the Start of Winter through Major Snow, follow the mean rate. Morning appearance: from the Winter Solstice, uniformly subtract four days. From Minor Cold through Major Cold, follow the mean rate. From the Start of Spring through Awakening of Insects, uniformly subtract three days. If within the Awakening of Insects qi, at the same solar distance as before, with no Jupiter, Mars, Saturn, or Venus visible in the morning, it is not seen. From Rain Water through the Start of Summer, it should appear but does not. If within the Start of Summer qi, at the same solar distance as before, with one or more of Jupiter, Mars, Saturn, or Venus visible in the morning, it is seen as well. From Minor Fullness through Cold Dew, follow the mean rate. From White Dew and Frost's Descent through the Start of Winter, uniformly add one day. From Minor Snow through Major Snow, follow the mean rate.
158
Procedure for Finding the Five Planets' Fixed Appearances
159
For each planet, take half of that star's daily correction constant at its regular appearance; apply diminish-increase at rest to the regular appearance day to obtain the fixed appearance day and parts. The five planets differ in brightness at rest and at exaltation; their phases of joy, anger, flourishing, and waning, and their apparent sizes, differ especially. When appearance varies from the regular date, whether early or late, examine its motion according to the sun's varying speed, measure its position, and take its distance from the sun as the fixed standard.
160
Procedure for Finding the Degree Where the Star Appears
161
宿退
Set the lodge-degree count and parts of the sun at midnight on the star's fixed appearance day; halve the solar motion difference, multiply by the fixed appearance remainder, and divide by the half-total; add for advance and subtract for retreat to the fixed appearance remainder, and add this to the midnight degree and parts; then apply that star's first-appearance solar distance—in the morning subtract and in the evening add—to obtain the lodge where the star first appears.
162
宿
Procedure for Lodge Degrees and Stepping the Planets
163
滿
For each planet, set its first-appearance day's correction constant, halve it, and at rest add or diminish to adjust its first-appearance motion-and-station day rate. For Jupiter and Saturn, no add-subtract adjustment is needed; follow the base procedure. If the add-subtract adjustment does not amount to a full day, combine it with the appearance date. If the remainder exceeds half, carry one day; if it does not reach half, do not carry. Then, according to the planet's day-and-degree motion rate, obtain the day's motion parts.
164
Procedure for Finding Where the Star Stands at Midnight After the First Appearance Day
165
滿退 宿
Set the star's fixed appearance remainder, subtract it from the half-total, multiply by that star's first-appearance motion parts, and divide by the half-total; add for direct motion and subtract for retrograde to the star's first-appearance fixed chen location in degrees and parts. If addition fills the divisor, or subtraction falls short, advance or retreat one degree. Count outside the prior assignation to obtain the star's lodge degree and parts at midnight after appearance. From here onward, for each star compute the daily motion in degrees; the day-degree reached and any increase in speed are all reckoned from midnight. If the chen has a fractional remainder, follow whichever is nearest.
166
Procedure for Stepping to Where the Star Reaches at the Next Day's Midnight
167
滿 滿 退
For each star, add or subtract its one-day motion in degrees and parts according to direct or retrograde motion. If the motion has fractional small parts, use the day rate as denominator. When the small parts fill the denominator, remove them and carry one into the motion parts. When the motion parts fill the half-total, remove them and carry one into the degrees. If the motion has increasing speed or increasing slowness, set aside the one-day motion parts separately. For each, add the slowness-or-speed difference as diminish or increase; if stationary, continue from the prior value; if retrograde, subtract accordingly. In direct motion exiting the Dipper, remove its parts; in retrograde motion entering the Dipper, first add the parts. When this is done, reduce the motion parts to degree parts by the rule factor for each day's arrival. For the five planets' later direct, stationary, and retrograde terminal day-degrees, use each star's invisibility degree to find its solar distance, near or far, and the day-degree reached by diminish-increase, thereby fixing the invisibility day. When annotating the calendar, discard the fractional parts for day-degrees and for Venus, Mercury, and the other stars.
168
Procedure for Finding Mean Motion Degree and Parts
169
滿 滿
Set the fixed degree rate, multiply by the half-total, carry any parts forward, divide by the day rate, and the quotient is the one-day motion parts. Any undivided small parts are carried into the motion parts. When the parts fill the half-total, convert them to a degree. This gives the one-day motion in degrees, motion parts, and small parts. Set the fixed day rate, subtract one day, multiply by the applied difference in parts, and divide by two to obtain the difference rate. For increasing speed, subtract the difference rate from the mean motion parts; for increasing slowness, add it; this yields the first day's motion in degrees and parts.
170
Star name, star motion, change day, first motion entering-qi calendar, motion day rate, motion degree and degree-parts rate: diminish-increase rate.
171
退西退 退西退
Jupiter: first direct motion, differential 114 days, travels 18°509 parts—one part slow at first, then fast—with a daily increase of 14 parts. Prior station: 26 days. Revolving retreat, moving westward: differential 30 days, retreats 6°12 parts. Slow at first, with speed increasing by 2 parts per day. Again retreats westward: differential 42 days, retreats 6°12 parts. Fast at first, with slowness increasing by 2 parts per day. Later station: 25 days. Later direct motion: differential 114 days, travels 18°509 parts. Slow at first while advancing, with speed increasing daily in parts until the days are exhausted; evening invisibility: 14 days.
172
滿 滿
Mars: first direct motion, from the Winter Solstice on the first day, rate 243 days for 165 degrees. From then on, every three days diminish the day count and degree count each by three. At Minor Cold on the first day: 235 days for 154 degrees. From then on, every two days diminish the day count and degree count each by three. From Grain Rain for four days at the mean rate through Minor Fullness for nine days. 178 days for 100 degrees. From nine days after entering Minor Fullness, every two days increase the day count and degree count each by one. From the Summer Solstice on the first day at the mean rate through six days. 171 days for 93 degrees. From six days after entering the Summer Solstice, every three days increase the day count and degree count each by one. At the Start of Autumn on the first day: 184 days for 106 degrees. From then on, every day increase the day count and degree count each by one. At White Dew on the first day: 214 days for 136 degrees. From then on, every five days increase the day count and degree count each by one. At the Autumn Equinox on the first day: 232 days for 154 degrees. From then on, every day increase the day count and degree count each by one. At Cold Dew on the first day: 247 days for 169 degrees. From then on, every five days increase the day count and degree count each by two. From Frost's Descent for five days at the mean rate through the Start of Winter for thirteen days. 259 days for 181 degrees. From thirteen days after entering the Start of Winter, every two days diminish the day count and degree count each by one. Again at the Winter Solstice on the first day: 242 days for 165 degrees.
173
退退
For each mean qi entered, where the rate is mean follow the base rate; from the remainder compute daily diminish-increase—this is called the prior-fast fixed day-and-degree rate. For prior slow motion and station-retreat entering qi where day-and-degree diminish-increase applies, compute daily diminish-increase by the same method as for fast motion, to obtain the fixed day-and-degree rates for slow, stationary, and revolving-retreat phases.
174
滿
Procedure for finding the change day rate: in this fast phase, from six days into Major Cold, diminish the day rate by one through Rain Water. From the Spring Equinox through the Start of Summer, reduce the day rate by ten. At Minor Fullness on the first day, reduce the day rate by ten. Afterward, every three days diminish the reduction by one. Through Grain in Ear, follow the mean rate. From the Start of Autumn, increase the day rate by one every three days through End of Heat. From White Dew through the Autumn Equinox, uniformly add ten to the rate. At Cold Dew on the first day, add ten to the rate. Afterward, every day and a half diminish the addition by one. Once the qi period is exhausted, follow the mean rate.
175
滿調
Procedure for finding the change degree rate: in this fast phase, from Major Cold through Awakening of Insects, from the Summer Solstice through Major Heat until the qi is exhausted, and from Frost's Descent through Minor Snow, add four to the degree rate in each case. From Clear Brightness through Grain Rain, add twelve to the rate in degrees. At first motion entering End of Heat, reduce the day rate by sixty and the degree rate by thirty. Set apart a prior-slow half-degree motion; when this day-degree is exhausted, the remaining day-and-degree rate from the reduction continues as fast motion. From White Dew through the Autumn Equinox: 44 days for 22 degrees. All of these use the prior-slow half-degree rate. First motion from Major Cold through Major Heat: differential motion, fast at first, with slowness increasing by one part per day. For each, obtain the motion parts by the method above. When the prior slow phase's latter day rate has been increased or diminished, and increasing slowness or increasing speed applies to the parts, take the prior fast phase's last-day motion parts as the prior slow phase's first-day motion parts. Subtract this from the prior slow mean motion parts; the remainder is the prior slow total difference. The latter fast phase's day parts serve as the latter slow phase's last-day motion parts. Subtract this from the latter slow phase's daily motion parts; the remainder is the latter total difference. The result of the subtraction is the latter separate day-difference parts. Any remainder that does not amount to a full unit is adjusted into minor parts. At transitions between slow and fast motion, decay and diminish of motion parts are not counted. Where the discrepancy is large, compute by this procedure. If the discrepancy is slight, each case follows the base method.
176
滿
Prior slow motion: direct differential motion from the Winter Solstice—60 days for 25 degrees. Fast at first, with speed increasing daily. From entering Minor Cold onward, every two days slow by two parts; diminish the day count and degree count each by one per day. At Major Cold on the first day: 55 days for 20 degrees. From then on, every three days increase the day count and degree count each by one. At the Start of Spring on the first day, follow the mean rate. Through Clear Brightness: 60 days for 25 degrees. From the Grain Rain qi onward, subtract one degree per solar term. At the Start of Summer on the first day, follow the mean rate. Through Minor Fullness: 60 days for 22 degrees. From entering Grain in Ear, add one degree per solar term. At the Summer Solstice on the first day, follow the mean rate. Through End of Heat: 60 days for 25 degrees. From entering White Dew onward, diminish one degree every three days. At the Autumn Equinox on the first day: 60 days for 25 degrees. From then on, add one to the day count each day and one to the degree count every day and a half. At Cold Dew on the first day: 60 days for 25 degrees. From then on, diminish one degree every two days. One day into the Start of Winter, follow the mean rate. Through the end of the qi period: 60 days for 17 degrees. From Major Snow onward, add one degree every five days. At Major Snow on the first day: 60 days for 20 degrees. From then on, add one degree every three days.
177
退西 退 退 退 退 退 退 退 退 退 退 退 退
Prior station: 13 days. If the prior fast phase diminished the day-rate by one, distribute that amount in parts to increase this station and the later slow day-rate. If the prior fast phase added to the day-rate, distribute that amount in parts to diminish the slow day-rate. Then revolving retreat, moving westward. On the first day of the Winter Solstice: 63 days retreating 21 degrees. From then on, add one degree every four days. One day into Minor Cold: 63 days retreating 26 degrees. From entering Minor Cold onward, diminish one degree every three and a half days. Three days into the Start of Spring, follow the mean rate. Through Awakening of Insects: 62 days retreating 17 degrees. From entering Rain Water onward, every two days increase the day count and degree count each by one. Eight days into Rain Water, follow the mean rate. Through the end of the qi period: 67 days retreating 21 degrees. From entering the Spring Equinox onward, every day diminish the day count and degree count each by one. Four days into the Spring Equinox, follow the mean rate. Through Grain in Ear: 63 days retreating 70 degrees. From entering the Summer Solstice onward, every six days diminish the day count and degree count each by one. At Major Heat on the first day, follow the mean rate. Through the end of the qi period: 58 days retreating 12 degrees. At the Start of Autumn on the first day, follow the mean rate. Through the end of the qi period: 57 days retreating 11 degrees. From entering White Dew onward, every two days increase the day count and degree count each by one. Twelve days into White Dew, follow the mean rate. Through the Autumn Equinox: 63 days retreating 70 degrees. From entering Cold Dew onward, every three days increase the day count and degree count each by one. Nine days into Cold Dew, follow the mean rate. Through the end of the qi period: 66 days retreating 20 degrees. From entering Frost's Descent onward, every three days diminish the day count and degree count each by one. Six days into Frost's Descent, follow the mean rate. Through the end of the qi period: 63 days retreating 17 degrees. From the Start of Winter onward, every three days increase the day count and degree count each by one. Eleven days into the Start of Winter, follow the mean rate. Through the end of the qi period: 67 days retreating 21 degrees. From entering Minor Snow onward, every two days diminish the day count and degree count each by one. Eight days into Minor Snow, follow the mean rate. Through the end of the qi period: 63 days retreating 17 degrees. From entering Major Snow onward, add one degree every three days.
178
Later station: stationary for 13 days at the Winter Solstice. From then on, add one day every two and a half days. From Major Cold on the first day at the mean rate through the end of the qi, stationary for 25 days. From entering the Start of Spring onward, diminish one day every two and a half days. At Rain Water on the first day, stationary for 13 days. From then on, add one day every three days. At Clear Brightness on the first day, stationary for 23 days. From then on, diminish one day each day. Ten days into Clear Brightness at the mean rate through the end of the qi, stationary for 15 days. From entering White Dew onward, every two days diminish one day and increase one day. Eleven days into the Autumn Equinox: no stationary period. From eleven days after the Autumn Equinox onward, add one day each day. At Frost's Descent on the first day, stationary for 19 days. From then on, diminish one day every three days. Three days into the Start of Winter at the mean rate through Major Snow, stationary for 13 days.
179
Later slow motion: direct differential motion—60 days for 25 degrees. Fast at first, with speed increasing by two parts per day. If the prior or later fast phase added degrees, subtract that amount in this slow phase to obtain the fixed degrees; If the prior fast phase added no degrees, subtract 3 degrees from this slow phase between the Autumn Equinox and the Start of Winter, and 5 degrees entering the Winter Solstice; if the later stationary fixed days fall short by 13, add the shortfall in days to this slow day-rate.
180
Later fast motion: at the Winter Solstice on the first day, rate 211 days for 131 degrees. From then on, every day diminish the day count and degree count each by one. Eight days into Major Cold: 172 days for 94 degrees. From eight days after entering Major Cold onward, every day diminish the day count and degree count each by one. At Awakening of Insects, follow the mean rate. Through the end of the qi period: 161 days for 83 degrees. From entering Rain Water onward, every three days increase the day count and degree count each by one. Three days into Grain Rain: 177 days for 99 degrees. From entering Grain Rain onward, every three days increase the day count and degree count each by one. Fourteen days into Grain in Ear, follow the mean rate. Through the Summer Solstice: 233 days for 150 degrees. From entering the Summer Solstice onward, every ten days increase the day count and degree count each by one. Five days into Minor Heat: 253 days for 175 degrees. From entering Minor Heat onward, every five days increase the day count and degree count each by one. From Major Heat on the first day at the mean rate through End of Heat: 263 days for 185 degrees. From entering White Dew onward, every two days diminish the day count and degree count each by one. One day into the Autumn Equinox: 255 days for 177 degrees. From one day after the Autumn Equinox onward, every day and a half restore the day count and degree count each by one. At Major Snow on the first day: 250 days for 120 degrees. From the Autumn Equinox onward, every three days increase the day count and degree count each by one. At the Winter Solstice on the first day, again: 210 days for 127 degrees. Where the fixed-qi day and degree rates require adjustment, tally the daily diminution and addition by the same method as the prior fast phase, and use the result as the later-fast fixed-degree rate.
181
退
Procedure for finding the transformed day-rate: if the prior slow fixed days fall short by 60, or the retrograde fixed days fall short by 63, add the shortfall in days to this fast fixed day-rate; if the prior slow fixed days exceed by 63, or the later stationary fixed days exceed by 13, subtract the surplus in days from this fast fixed day-rate. Once addition and subtraction are complete, that is the transformed day-rate.
182
退 退
Procedure for finding the transformed degree-rate: if the prior slow fixed degrees fall short by 25, the retrograde fixed degrees exceed by 17, or the later slow phase diminishes degrees between the Autumn Equinox and the Winter Solstice, add the surplus or shortfall in degrees to this fast fixed degree-rate. If the prior slow fixed degrees exceed by 25, or the retrograde fixed degrees fall short by 17, subtract the surplus or shortfall in degrees from this fast fixed degree-rate. Once addition and subtraction are complete, that is the transformed degree-rate.
183
First motion from the Spring Equinox through Grain Rain: differential motion. Slow at first, with speed increasing by one part per day. First motion from the Start of Summer through the Summer Solstice: half a degree per day. 66 days for 22 degrees. At Minor Heat: 50 days for 25 degrees. From the Start of Autumn through the end of the qi: 20 days for 10 degrees; diminish the rate and continue motion by the same initial-slow method as the prior fast phase. Apply diminish-increase as before to obtain the motion parts. Each leg completes its degrees, then evening invisibility.
184
退西退
Saturn: initial direct motion, differential 83 days, travels 7°290 parts. Fast at first, with slowness increasing by half a part per day. Prior station: 37 days. Then retrograde, moving westward: differential 51 days, retreats 30 parts. Slow at first, with speed increasing by a small half part per day.
185
滿 退西退 退西退 退 滿 滿 滿
Venus: evening appearance, direct motion from the Winter Solstice through the Start of Summer, and from the Start of Autumn through Major Snow. 172 days for 206 degrees. From entering Minor Fullness onward, add one degree every ten days to obtain the fixed fast rate. First entering White Dew through the Spring Equinox: differential motion. Fast motion, with slowness increasing by two parts per day. The remainder follows uniform motion. From the Summer Solstice through Minor Heat: 172 days for 209 degrees. From entering Major Heat onward, diminish one degree every five days through the end of the qi. Uniform motion: from the Winter Solstice on the first day and from Major Heat, each through the end of the qi. 13 days for 13 degrees. From entering the Winter Solstice onward, diminish one every ten days through the Start of Spring; from entering the Start of Autumn, add one each day through the Autumn Equinox. From Awakening of Insects through Grain in Ear: 7 days for 7 degrees. From entering the Summer Solstice onward, add one every five days through Minor Snow. At Cold Dew on the first day: 33 days for 22 degrees. From then on, diminish one every six days through Minor Snow. Direct slow motion: differential 32 days for 30 degrees. Fast at first, with slowness increasing by eight parts per day. If the prior fast phase added degrees beyond 206, subtract that excess from this degree count. Evening station: 7 days. Evening retrograde, moving westward: 10 days retreating 5 degrees. When the days are exhausted, evening invisibility. Morning initial retrograde, moving westward: 10 days retreating 5 degrees. Half a degree of retrograde motion per day. Morning station: 7 days. Direct slow motion, differential from the Winter Solstice through the Start of Summer, and from Major Snow through the end of the qi. 32 days: slow at first, with speed increasing by eight parts per day. From entering Minor Fullness onward, diminish one degree every ten days through Grain in Ear. Uniform motion: from the Winter Solstice through the end of the qi, and from the Start of Summer through the end of the qi. 13 days for 13 degrees. One degree per day. From entering Minor Cold onward, every six days increase the day count and degree count each by one through Awakening of Insects. From entering Minor Fullness onward, every seven days diminish the day count and degree count each by one through the Start of Autumn. At Rain Water on the first day: 23 days for 23 degrees. From then on, every six days diminish the day count and degree count each by one through Grain Rain. From End of Heat through Cold Dew: no such uniform motion. From entering Frost's Descent onward, every five days increase the day count and degree count each by one through Major Snow. If the prior slow phase diminished degrees by less than 30, add that amount in this fast phase. Fast motion: 172 days for 206 degrees. From End of Heat through Cold Dew: differential motion, slow at first, with speed increasing by one part per day. The remainder follows uniform motion until the motion days are exhausted, then morning invisibility.
186
Mercury: evening appearance, direct fast motion, 12 days for 21°6 parts. One degree 503 parts per day. From Major Heat through End of Heat: 12 days for 17°2 parts. One degree 280 parts per day. Uniform motion: 7 days for 7 degrees. From entering Major Heat onward, every two days diminish the day count and degree count each by one. From entering the Start of Autumn: no such uniform motion. Direct slow motion: 6 days for 2°4 parts. 224 parts per day; if the prior fast phase traveled eleven degrees, there is no such slow motion. When the days are exhausted, evening invisibility. Evening station: 5 days. Morning appearance: stationary for 5 days. Direct slow motion: 6 days for 2°4 parts. 224 parts per day. From Major Cold through Awakening of Insects: no such slow motion. Uniform motion: 7 days for 7 degrees. One degree per day. From Major Cold onward, every two days diminish the day count and degree count each by one. From entering the Start of Spring: no such uniform motion. Direct fast motion: 12 days for 21°6 parts. One degree 503 parts per day. If there was no prior slow phase: 13 days for 17°10 parts. One degree 280 parts per day. Each leg completes its days, then morning invisibility.
187
Generally, the five planets' leftover fractional day-parts are all absorbed into invisibility; they therefore need not appear separately in the planetary tables.
188
便
While Empress Wu held regency, an edict said: "Recently the office charged with making the calendar took the twelfth month as intercalary. Examination of the historical records showed that this violated longstanding precedent, with the result that within the previous year the moon was still visible on the last day of the month. On further investigation, it was indeed off by one day. Establishing the year's beginning and setting the calendar right belong to this matter. The calendar should be revised afresh, and past errors corrected. This month may be taken as intercalary tenth month, and the coming month as first month." That year obtained a jiazi-day conjunction at new moon on the Winter Solstice. Thereupon the era was changed to Sacred Calendar, with the zi-established month as the first month, the chou-established month as the twelfth month, and the yin-established month as the first month of the year. The Grand Astrologer Gautama Siddhartha was ordered to compose a new calendar. By the third year, the Xia seasonal system was restored, and the Guangzhai Calendar was likewise not used. When Emperor Zhongzong restored the dynasty, Vice Director of the Grand Astrologer's Office Nangong Shuo memorialized: "The Linde Calendar's added times have grown increasingly loose. Moreover, at the head of the upper origin in the jiazi year, when the five stars entered qi and added times, this did not match the correct conjunction of jade disk and linked pearls." Thereupon an edict ordered Shuo, together with Calendar Commissioner Xu Baoyi and Nangong Jiyou, to further revise the Yisi Origin Calendar. By the Jinglong era the calendar was completed, and an edict ordered its adoption. Soon afterward Emperor Ruizong acceded to the throne, and the Jinglong Calendar was set aside and not used. The Linde Calendar Canon is here briefly recorded in the main outlines of its method.
189
Mother divisor: 100. Twice the Dayan number serves as the mother divisor.
190
Ten-day cycle: 60. The terminal number of the six jia cycles serves as the ten-day cycle.
191
Chronogram divisor: 8 double-hours; parts, 33 and a little less than half. Divide 100 marks by the twelve chronogram count to obtain the chronogram divisor.
192
Period cycle: 365 days; remainder, 24; odd, 48. The total days and remainder-and-odd numbers of one period serve as the period cycle.
193
Qi divisor: 15 days; remainder, 21; odd, 85 and a little less than half. Divide the period cycle by the twenty-four qi to obtain the qi divisor.
194
Pentad divisor: 5 days; remainder, 7; odd, 28; minor parts, 4. Divide the period cycle by the seventy-two pentads to obtain the pentad divisor.
195
Month divisor: 29 days; remainder, 13; Odd parts. This serves as the month divisor.
196
The day divisor is the interval to one new-moon conjunction and its remainder and odd parts, obtained from the sun's elongation and the moon's recession.
197
Full-moon divisor: 14 days; remainder, 76; odd, 53. This also serves as the yin posterior limit. Halve the month divisor to obtain the full-moon divisor. It is also the limit after the moon, traveling the yin calendar, meets new and full moon crossings.
198
Quarter-moon divisor: 7 days; remainder, 38; odd, 26 and a half. Take one quarter of the month divisor to obtain the quarter-moon divisor.
199
Intercalation difference: 10 days; remainder, 87; odd, 76. Cast month divisors out of the period cycle; the remainder is the intercalation difference.
200
Submergence number: 91; remainder, 31; odd, 12. Quarter the period cycle; the quartered remainder gives the submergence number.
201
Submergence method: 1; remainder, 31; odd, 12. Subtract the ten-day cycle from the period cycle and quarter the remainder to obtain the submergence method.
202
Lunar circuit method: 27 days; remainder, 55; odd, 45; minor parts, 59. The count for the moon's fast-and-slow circuit of one cycle serves as the lunar circuit method.
203
Lunar difference method: 1 day; remainder, 97; odd, 60; minor parts, 41. Subtract the lunar circuit method from the month divisor; the remainder is the lunar difference.
204
宿
Circuit-of-heaven method: 365 degrees; remainder, 25; odd, 71; minor parts, 13. The total degrees of the twenty-eight lodges, their total interstitial distances, and the remainder and odd parts serve as the circuit-of-heaven method.
205
Nodal-cycle method: 27 days; remainder, 21; odd, 22; minor parts, 16 and 7 parts. The day count for the sun's circuit through yin and yang to one nodal crossing serves as the nodal-cycle method.
206
Crossing-difference method: 2 days; remainder, 31; odd, 83; minor parts, 83 parts. Subtract the nodal-cycle method from the month divisor to obtain the crossing-difference method.
207
Mid-crossing method: 13 days; remainder, 60; odd, 61; minor parts, 3 and a half. Halve the nodal cycle to obtain the mid-crossing method.
208
Yang anterior limit: 12 days; remainder, 44; odd, 69; minor parts, 16 and 7 parts. The limit within which the moon, traveling the yang calendar, meets new and full moons.
209
Yang posterior limit: 1 day; remainder, 15; odd, 91; minor parts, 91, 6 parts, and a half. The limit after the moon, traveling the yang calendar, meets new and full moons.
210
Yin anterior limit: 26 days; remainder, 5; odd, 30; minor parts, 25 and a half part. The limit before the moon, traveling the yin calendar, meets new and full moons.
211
Jupiter accord method: 398 days; remainder, 86; odd, 79; minor parts, 80.
212
Mars (Fire-Brilliance) synodic constant: 779 days; remainder, 90; odd parts; 55; minor parts, 45.
213
Saturn (Queller-Star) synodic constant: 378 days; remainder, 8; odd parts, 4; minor parts, 80.
214
Venus (Great White) synodic constant: 583 days; remainder, 91; odd parts, 77; minor parts, 70.
215
Mercury (Chronogram-Star) synodic constant: 115 days; remainder, 87; odd parts, 95; minor parts, 70.
216
At the Supreme Ultimate Superior Origin, in the yisi year, on the eleventh month's jiazi day when new moon and winter solstice coincided—the start of the Yellow Bell, at midnight, with the Dipper's balance-beam tail set at the center of zi—sun and moon lay like a joined jade disk and the five planets like strung pearls, all rising from the first tracks of Xingji and Qianniu. Now Great Tang again places the year in the yisi cycle, with an accumulated count of 414,360 beyond the origin. To verify backward into antiquity, subtract one count per year. To project forward into the future, add one count per year. The accumulated numbers of the Yisi Origin Calendar method are broadly as described above. The computational classic does not record them.
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