 | THE HISTORY OF THE FORMER HAN DYNASTY The history of the former Han dynasty |  |
V. APPENDIX V
SOLAR ECLIPSES DURING THE FORMER HAN PERIOD
The results derived from an examination of the eclipses reported in the
HS are here summarized. During this period of 230 years (including the
reign of Wang Mang) there occurred 559 solar eclipses, of which 98 or
17.5% were visible in some part of China. Fifteen of these were very
small eclipses or were invisible in the capital, so that we should not expect
Chinese astronomers to have noticed them. Of the remaining 83 solar
eclipses, 55 or almost two-thirds seem to have been recorded by Chinese
astronomers. In order to examine this unusually good record, I present
here a list of the solar eclipses visible in China from 206 B.C. to A.D. 23,
with my conclusions.[1]
As sources for these eclipses recordings, there is (1) the SC, which
contains very few of these recordings, so that its value is almost negligible.
(2) The "Annals" and ch. 99 of the HS constitute a second source, giving
only the dates of these eclipses. (3) HS ch. 27, "The Treatise on the
Five Powers," near the end, contains a list of solar eclipses, which partly
duplicates the information contained in the "Annals" and partly amplifies
it by noting a few additional solar eclipses, giving the heavenly location
of many eclipses, sometimes other information, and often presenting their
astrological interpretation. This list ends with the reign of Emperor
P'ing, so that the eclipses during A.D. 6 to 23 are only mentioned in
ch. 99 of the HS. (4) The Han-chi seems to be an entirely secondary
was written in the second century A.D., it constitutes an early check upon
the text of the HS, and very occasionally furnishes additional information.
The information found in these four sources is discussed in the appendixes
of the various chapters concerning eclipses, and need not be repeated here.
SOLAR ECLIPSES VISIBLE IN CHINA, 206 B.C. to A.D. 23
206 B.C., July 6. Not noticed.
205, Jan. 1. Not noticed.
205, Dec. 20. Recorded correctly (HFHD, I, 165, i).
201, Oct. 8. Possibly recorded (ibid., ii); if so, as for all eclipses not noted
as "recorded correctly," the Chinese date must be emended.
198, Aug. 7. Recorded correctly (HFHD, I, 166, iii).
197, July 26. Not noticed.
195, June 6. Not noticed.
194, May 26. Not noticed.
192, Sept. 29. Probably recorded (HFHD, I, 188, i).
188, July 17. Recorded as total (HFHD, II, 189, ii).
A false solar eclipse is listed for July 26, 186 (HFHD, I, 211-12, i).
184, May 6. Hardly visible and seemingly not noticed (ibid.).
181, Mar. 4. Recorded correctly, total at the capital (HFHD, I, 212, ii).
178, Jan. 2. Recorded correctly (HFHD, I, 284, i). A small partial
eclipse, only reaching a magnitude of 0.20 (totality = 1.00) at the
capital.
The SC notes a solar eclipse for Jan. 17, 178, which was actually the
date of a lunar eclipse (ibid., ii).
178, Dec. 22. Recorded correctly (ibid., iii).
176, June, 6. Probably recorded (HFHD, I, 285, iv).
174, Oct. 10. Not noticed.
173, May 4. Not noticed.
169, July 17. Not noticed.
167, May 28. Not noticed
166, May 17. Not noticed.
164, Mar. 26. Hardly visible, magnitude 0.02 (ibid.).
162, Mar. 5. Hardly visible. Invisible in the north (ibid.).
161, Aug. 16. Possibly recorded (HFHD, I, 286, v).
155, Oct. 10. Possibly recorded (ibid., vi).
154, Apr. 4. Recorded (HFHD, I, 335, i). The three sources here all
disagree on the day of the eclipse.
An eclipse listed for 153 may have been dittography for the eclipse
of 145 (ibid., ii).
152, Aug. 8. Hardly visible (ibid.). Invisible at the capital; magnitude
of 0.08 at Peiping.
151, Feb. 2. Hardly visible (ibid.); magnitude of 0.03 at the capital.
150, Jan. 22. Recorded correctly (ibid., 336, iii).
149, June 7. Very probably recorded (ibid., iv).
An eclipse listed for Oct. 22, 148 is almost certainly dittography for
the eclipse of 147 (ibid., 337, v).
147, Nov. 10. Recorded correctly (ibid., vi); almost total (0.77).
145, Mar. 26. Possibly recorded (ibid., 338, vii); if so, reported from the
tip of eastern Shantung.
144, Sept. 8. Recorded correctly (ibid., viii).
143, Aug. 28. Recorded correctly (ibid., 339, ix).
The SC states that in the month Nov. 16-Dec. 14, 142, "the sun
and moon were both eclipsed and red for five days." The HS does
not mention this eclipse, which may have been a dust storm (ibid. x).
141, July 8. Possibly recorded (HFHD, II, 136, i).
138, Nov. 1. Recorded correctly (ibid., ii).
136, Apr. 15. Probably recorded (ibid., iii).
135, Apr. 5. Probably recorded (ibid., 137, iv).
134, Aug. 19. Recorded correctly (ibid., 138, v).
127, Apr. 6. Recorded correctly (ibid., vi).
124, Feb. 3. Hardly visible and that only in southern Mongolia (ibid.
139, vii).
123, Jan. 23. Very probably recorded (ibid.).
122, July 9. Recorded correctly (ibid., viii).
115, Aug. 19. Reached a magnitude of 0.28 at 11:21 a.m. at the capital,
so that it was not conspicuous. But smaller eclipses were recorded
(ibid., 140).
112, June 18. Recorded correctly (ibid., ix).
108, Apr. 6. Possibly recorded; reached a magnitude of 0.32 at the
capital (ibid., x).
107, Sept. 19. Invisible at the capital; reached a magnitude of 0.34 at
Peiping at sunrise, where it was conspicuous. Not mentioned (ibid.)
104, July 19. Not mentioned; reached a magnitude of 0.62 at the
capital (ibid.).
103, Dec. 3. Not mentioned; reached a magnitude of 0.12 at the capital
(ibid.).
101, May 17. Not mentioned; reached a magnitude of 0.45 at the
capital (ibid.).
96, Feb. 23. Recorded correctly, if Hoang's calendar is corrected by
altering the intercalary month according to a recently excavated
93, Dec. 12. Recorded correctly (ibid., xii).
90, Oct. 11. Not conspicuous; reached a magnitude of 0.17 at sunrise
at the capital (ibid., 142, xiii).
89, Sept. 29. Recorded correctly (ibid.).
84, Dec. 3. Recorded correctly (HFHD, II, 178, i).
82, May 18. Not mentioned (ibid., 179).
81, May 6. Not mentioned; invisible at the capital, but reached a magnitude
of 0.47 shortly after sunrise at Peiping (ibid.).
80, Sept. 20. Recorded correctly; almost total at the capital and total
in the provinces, from which its totality was reported (ibid., 178, ii).
75, Jan. 3. Visible only in south China (HFHD, II, 275, i).
73, May 8. Not mentioned (ibid.)
69, Feb. 25. Not mentioned (ibid.).
68, Feb. 13. Recorded correctly, although at the capital it only reached
a magnitude of 0.10 at 4:20 p.m. (ibid.).
68, Aug. 9. Not mentioned (ibid., 276).
61, Sept. 20. Not mentioned (ibid.).
58, July 20. Not mentioned (ibid.).
57, July 9. Not mentioned (ibid.).
56, Jan. 3. Recorded correctly, although it was invisible at the capital
and at Peiping it only reached a magnitude of 0.18 at sunrise
(ibid., 275, ii).
54, May 9. Recorded correctly (ibid., 276, iii).
53, Oct. 21. Not mentioned (HFHD, II, 354, i).
50, Aug. 21. Not mentioned (ibid.).
49, Aug. 9. Not mentioned (ibid.).
47, June 19. Not mentioned (ibid.).
42, Mar. 28. Recorded correctly (ibid.).
40, July 31. Recorded correctly (ibid., ii).
39, July 20. Hardly visible; only reached a magnitude of 0.07 at the
capital (ibid., 355, iii).
38, Jan. 14. Hardly visible; only reached a magnitude of 0.02 at sunset
at the capital (ibid.).
36, Nov. 12. Not mentioned. Reached a magnitude of 0.29 at sunrise
at the capital (ibid.).
35, Nov. 1. Recorded, with an error of a year in the date. The record
indicates that it was a sunset eclipse of large magnitude; this is the
only eclipse of the sort within many years (ibid.).
29, Jan. 5. Recorded correctly (HFHD, II, 419, i).
28, June 19. Recorded correctly; total near the capital; the Annals say
26, Oct. 23. Recorded correctly (ibid., iii).
25, Apr. 18. Recorded correctly (ibid., 420, iv).
24, Apr. 7. Recorded correctly (ibid., v).
16, Nov. 1. Recorded correctly (ibid., vi). The Treatise says it was
seen only in the capital. At that place it only reached a magnitude
of 0.08 at 4:29 p.m.; its small magnitude prevented it being noticed
elsewhere. It could only have been seen by using a mirror, smoked
glass, or other special means. The court astronomers must have
been watching carefully for eclipses.
15, Mar. 29. Recorded correctly (ibid., 421, vii). The Treatise states
that clouds prevented this eclipse being seen in the capital, but it
was seen elsewhere, proving that reports of eclipses were sent in to
the central government.
14, Mar. 18. Recorded correctly (ibid., viii).
13, Aug. 31. Recorded correctly (ibid., ix).
12, Jan. 26. Recorded correctly (ibid., 422, x). It only reached a
magnitude of 0.07 at the capital and lasted only 67 minutes.
2, Feb. 5. Recorded correctly (HFHD, III, ch. 11: app. II, i). Almost
total at the capital.
1 B.C., June 20. Recorded with an error in the day (ch. 11: app. II, ii).
It only reached a magnitude of 0.06 at sunset at the capital.
A.D. 1, June 10. Recorded correctly (12: app., i).
2, Nov. 23. Recorded correctly (12: app., ii). It is stated to have been
total, but its totality was visible in northern Shensi and Honan, so
that this fact was reported from outside the capital.
4, Apr. 8. Hardly visible; invisible at the capital, and at Peiping reached
only a magnitude of 0.15 (99: app. IV, i).
6, Sept. 11. Recorded with a slight textual error in the date. It
reached a magnitude of 0.95 at the capital (ibid., 544, i).
10, June 30. Hardly visible. Only visible in present Ninghsia (99:
app. IV, i).
14, Apr. 18. Recorded correctly (ibid., ii).
15, Sept. 2. Hardly visible; invisible at the capital; at Peiping it only
reached a magnitude of 0.07 (ibid., 545, iii).
16, Aug. 21. Recorded correctly (ibid.).
19, Dec. 15. Hardly visible. Visible only in south China; at Canton it
only reached a magnitude of 0.03 (ibid.).
From a study of the above material, there emerge several interesting
conclusions:
1. The records of eclipses in Former Han times are predominatingly
are recorded correctly in the present text. Considering the length of time
since the HS was written in the first century A.D., and the many opportunities
for mistakes, both by astronomers and annalists before the
HS was compiled and the opportunities for errors in transmitting the HS
text, this is an excellent record. Fourteen other eclipses can be fitted
into the actual dates, usually by only slight changes in the text. Only at
most three recordings are hopelessly erroneous; two of these are due to
errors in the transmission of the data. When we consider how very easy
it is to write mistakenly the number of a month or the cyclical day, the
essential correctness of the HS is a marked evidence of the care that was
exercised in compiling it and in preserving and copying faithfully its text.
It does not seem to have been the case in Han times, as was sometimes
later the case, that the dates given in the history were those on which
the emperor was informed of an event, rather than the dates on which
events occurred. The eclipse of 15 B.C. is said to have been reported
from outside the capital and to have been invisible in the capital, so that
some days must have elapsed between its occurrence and its being reported
to the throne. But it is dated correctly.
2. In the case of some eclipses that are not listed correctly, it is plain
that the errors of dating occurred before the HS was compiled. In other
cases the evidence is not so clear, but it looks as if the same thing happened.
The description of the eclipse of 35 B.C. as being large and ending
at sunset is such that the actual eclipse can be unmistakeably identified
by calculation. In the chronological account of events in the Annals,
this eclipse is put more than a year later than it actually happened; between
the actual date and the date at which the Annals put it, several
events are recorded. Hence it is plain that when Pan Ku composed the
"Annals," this eclipse was already misdated. In the eclipses of 192 and
141, it also seems very likely that the error of dating occurred before
Pan Ku prepared his HS. He or his sources probably had somewhat
illegible astronomical records of eclipses, which were easily misread. As
a whole, there seem indeed to have been made more errors of dating
before the HS was written than have occurred in the transmission of the
text since that time.
In other cases, minor changes have plainly been made since the HS
was composed. With the eclipse of 192, there seems to have been later
conflation between the account in the "Annals" and that in the "Treatise."
A later correction of a date has possibly been made in connection
with the eclipse of A.D. 1. For the eclipse of 154, three different cyclical
dates are given by our three sources.
Dittography in Pan Ku's sources seems to have been responsible for the
eclipse listed for 153, and almost certainly for that listed for 148. The
reign of Emperor Ching (157-141 B.C.) was the worst period in accuracy
of eclipse recordings. During this period there are five eclipses incorrectly
dated, two dittographies, and only four correctly recorded eclipses.
The "Annals" for this period are also the least satisfactory of all the
"Annals" in the HS. The original sources for this reign seem to have
been defective.
3. Ch'ang-an, the imperial capital, was not the only place from which
eclipses were observed. The remarks in the HS in connection with the
eclipse of 15 B.C. establish by direct testimony the fact that eclipses were
reported from outside the capital. The eclipses of 136, 135, 80, and 56
must also have been reported from outside the capital. It is hence
dangerous to take the capital as the sole point of observation, as Hoang
and others have done. Nothing less than the whole of China should be
taken as the possible locus of observation. For Han times, there is however
some evidence that eclipses were not reported to the capital from
central and southern China; the eclipse of 2 B.C. was total in the present
southern Szechuan, southern Hunan, and Foochow, but no statement of
its totality got into the HS.
4. During long periods of years, all eclipses plainly visible in China
(and some quite small ones) are reported, while during other periods,
groups of eclipses are missed. The following table indicates the number
of eclipses not mentioned in the HS and the number of years after the
last unreported and plainly visible eclipse during which all plainly visible
eclipses were reported:
| Number of missed eclipses | 2 | 1 | 3 | 5 | 1 | 3 | 1 | 1 | 2 | 4 | 4 | 1 | ||||||||||||
| Years in which all plainly visible eclipses were recorded |
1 | 1 | 18 | 51 | 9 | 8 | 6 | 7 | 1 | 2 | 9 | 61 |
century during which all plainly visible eclipses were recorded—from 166
to 115 B.C. and from 35 B.C. to the first eclipse correctly recorded in
Later Han times (A.D. 26). What could have been the reason for such
periods of complete success followed by periods of failure? For example,
the five plainly visible eclipses between 174 and 166 B.C. were all missed,
then all plainly visible eclipses during 51 years down to 115 B.C. were
recorded.
Bad weather could hardly be the reason; eclipses were reported from
outside the capital, so that local bad weather would hardly prevent an
eclipse visible to the naked eye from being recorded. There is however a
small correlation between the number of eclipses missed and the time
| months | ||||||||||||
| Jan. | Feb. | Mar. | Apr. | May | June | July | Aug. | Sept. | Oct. | Nov. | Dec. | |
| Number of eclipses missed in the month |
1 | 1 | 0 | 0 | 7 | 2 | 5 | 3 | 1 | 3 | 1 | 1 |
| Number of eclipses recorded in the month |
6 | 3 | 3 | 8 | 3 | 6 | 4 | 6 | 5 | 3 | 5 | 4 |
| Aver. number of overcast days in month at Ch'ang-an[2] |
9 | 8 | 9 | 12 | 9 | 9 | 7 | 10 | 9 | 10 | 10 | 10 |
especially May and July, more than half coming during four consecutive
months. Yet the correlation between the number of eclipses missed in
each month and the number recorded is only -0.34, with a probable
error of ±0.17. There is thus only a very moderate degree of association
between the number missed and the number recorded, and the number of
instances is too low to make the correlation reliable. The correlation
between the number of eclipses missed and the average number of overcast
days is -0.39 ± 0.17, a negligible amount. It however looks
very much as if the interest taken in the observation of solar eclipses
by the responsible observers determined whether eclipses were or were
not observed. To be conspicuous (so that an eclipse could not be missed
by ordinary people) an eclipse must reach a magnitude of 0.75 when
the sun is high or a magnitude of 0.33 when the sun is near the horizon.
Many of the eclipses recorded in the HS are much smaller than these
magnitudes, so that they could not have been perceived unless astronomers
were expecting them and used special means to observe them.
Hence the attitude of the responsible observers or astronomers probably
had much to do with the observation or non-observation of solar eclipses.
5. The Chinese used special means to observe eclipses and watched for
them during the two or three days at the end and beginning of the
Chinese months when solar eclipses were to be expected. Unless an
diminution of light is too small to be perceived. Unless the sun is near
the horizon or is covered by light clouds, it cannot moreover be watched
with naked eyes. The necessary diminution of light can be obtained by
looking through smoked mica or at the reflection of the sun in water or in
a mirror. (Smoked glass may have been available at the time, mica was
actually used as a screen, cf. 99 B: 16b.) Some of the recorded eclipses
were so small that such special means were certainly used by Chinese
astronomers. The eclipse of 178 only reached a magnitude of 0.20; that
of 68 only a magnitude of 0.10; that of 16, only 0.08; that of 12, only a
magnitude of 0.07 lasting only 67 minutes; that of 1 B.C., only a magnitude
of 0.06. That such small eclipses were recorded demonstrates that
eclipses were expected and watched for, using special means. There was
an office at the capital entitled the Office for Watching the Heavens (cf.
Glossary, sub voce), the members of which probably scrutinized the sun
for eclipses. Probably this practise of watching for eclipses was however
confined to the capital; the eclipse of 16 B.C. was not reported from outside
the capital, although at the present Peiping it reached a magnitude
of almost twice that at the capital. Thus astronomical activity reached
high levels at the capital and was largely confined there.
6. As is to be expected, the method of calculation given by Neugebauer
shows itself remarkably accurate when its results are compared with
Chinese records. In the eclipse of 181, Chinese records show that at
Ch'ang-an the eclipse was total; calculation by Neugebauer's tables
reaches that result, but Oppolzer and Ginzel both reach a different result.
For the eclipse of 89, Chinese records give its time, late afternoon, which
also checks, to a reasonable degree of accuracy, with the results of calculation
by Neugebauer's tables. In this case, the eclipse seems merely
not to have been noticed until some time after it began.
By Neugebauer's tables, the time of an eclipse may be determined to
within fifteen minutes and the magnitude to within 0.03.[3]
The eclipse of
136 may have actually been observed at the capital, although, according
to Neugebauer's method of calculation, the capital was just outside the
area of visibility.
7. The differences between the statements about eclipses in the "Annals"
and in the "Treatise on the Five Powers" (HS ch. 27) indicate
that the latter probably represents the list of eclipses kept by the astrologers
at the capital, while the "Annals" also employ reports from outside
state that the eclipse was total, while the "Treatise" says it was
almost total. In each case, calculation demonstrates that at Ch'ang-an
it was almost total, while at some other places in China it was total. Thus
we can identify the "Treatise" with the reports of the astronomers at
the capital.
Yet the astrologers at the capital sometimes utilized reports from
elsewhere. The "Treatise" specifically mentions the observation of an
eclipse in other parts of China, in connection with the eclipse of 15. It
lists the eclipse of 135, which was not visible at the capital, as well as
that of 136, which was close to the borderline of visibility there. The
"Treatise" also records the eclipse of A.D. 2 as total, whereas calculation
shows that at Ch'ang-an it was not quite total.
8. It is possible that the eclipse listed for 186 was a deliberate fabrication
for the purpose of warning the ruler, the Empress of Emperor Kao,
that Heaven disapproved of her acts. This listing seems hardly explicable
by any other means. The eclipse discussed under the date 155 is
also either a fabrication or else an actual eclipse dated a few years ahead.
The eclipse of 201 is likewise doubtful. That only these three eclipses,
all near the beginning of this period, should be doubtful, is a high testimony
to the accuracy of Chinese recordings at this time. According to
Chinese law, it was a serious and capital crime to report falsely a prodigy
(such as an eclipse of the sun, cf. HS 100 A: 5b, to be translated in the
Preliminary Volume of this series).
9. There is no evidence that the Chinese by calculation reached the
dates of any eclipses recorded in the period. In the most promising cases,
those of 201, 184, 155, and 145 B.C., I tried to calculate these eclipses
by the methods that might have been used, and in each case reached
negative results.
For the mistakenly dated eclipse of 201, I counted forwards from the
date given for this eclipse to the end of the Former Han period by the
Han eclipse period of 3986⅔ days, by the Han chang of 6939 61/81 days,
and by the saros of 6585.3 days, without coming upon any solar eclipses.
Since it might have been possible for Chinese astronomers to know that
there is a lunar period lasting one month, during which two solar eclipses
and one lunar eclipse or two lunar eclipses and one solar eclipse may occur
(although no evidence of this knowledge is found in Han records), I also
took periods of one lunation from the dates found by this counting, but
came upon no solar eclipse visible in China. This eclipse could thus
hardly have been a calculation and its date must merely have been an
error of some sort.
In the case of the eclipses listed in 186 and 145, I performed a similar
calculation, with similar negative results. For the actual eclipse of 145
(not the mistaken date given in the "Annals," which does not correspond
to any actual eclipse), I counted forwards and backwards for the whole
Former Han period by the Chinese eclipse period of 3986⅔ days. At each
date thus found, an eclipse had occurred, but most of these eclipses were
invisible in China. The second eclipse period after was the date of the
eclipse of 123, the sixth was that of the eclipse of 80, the eleventh, that
of 25, and the twelfth, that of 14 B.C. In addition, the eclipses of 167,
58, 47 B.C. and A.D. 19 occurred in this series, but these four eclipses
are not recorded in the HS. The four recorded eclipses do not occur in
any regular sequence, so that the probabilities are decidedly against this
eclipse having been calculated by the Chinese eclipse period. I made a
similar calculation, using the Han chang of 6939 61/81 days, but no
recorded eclipse was found, only the missed eclipse of 164 and two invisible
eclipses. Calculation by the saros of 6585.3 days, used by Greek
astronomers, brought the eclipses of 181, 145, 127, and 1 B.C., the missed
eclipse of 73, together with invisible eclipses. The saros does not however
seem to have been known to the ancient Chinese. Thus even calculation
of a difficultly visible eclipse from the actual date of that eclipse does not
bring any results that would seem to encourage the computation of
eclipses or to make probable the hypothesis that they were computed by
the ancient Chinese.
It is however interesting that the first eclipse listed for Later Han times,
dated on Feb. 16, A.D. 25, was almost certainly calculated. It is not
found in the list of eclipses in the relevant "Treatise" of the History of the
Later Han Dynasty, which was compiled by Szu-ma Piao, who lived
ca. 240-306. This eclipse is listed in the Ku-chin Chu, written about
A.D. 300. Calculation shows that this partial eclipse was invisible in
Asia, and was confined to Alaska, western North America, and the eastern
Pacific Ocean (cf. p. 509, n. 3). This date cannot thus have been the
result of any Chinese observation; since the Chinese listing agrees with
the date of the actual but invisible eclipse, it must have been calculated.
Both Hoang and Chu Wen-hsin however include it in their lists of Chinese
eclipses. This eclipse shows how dangerous it is to accept an eclipse
listing without scrutiny.
Perhaps the most peculiar eclipse is that of 145 B.C., which was visible
only at sunrise at the tip of the Shantung peninsula. I have pointed out
that for it calculation was quite unlikely; since it was visible to the naked
eye, it was probably observed and reported to the capital.
10. The court astronomers seem to have kept lists of lunar eclipses as
One such lunar eclipse got into the SC (that of 178), probably because
Szu-ma Ch'ien or his source misread the word for "lunar" as "solar" in
his source. Eclipses of the moon were not believed to portend anything
important, so were not recorded in the histories.
11. Where the dates in the Chinese text do not correspond to any
actual eclipse, slight emendations nearly always enable us to show what
was the original date. The eclipse of 35 B.C. shows that such emendations
actually reach the original dating. In this case, the eclipse is described
in such a way that there is no doubt which eclipse is denoted by
the recording. To reach the correct date, it is necessary to change a 5
in the year to a 4, a 6 in the month to a 9, and a jen-shen [OMITTED] in the date to
a ting-ch'ou [OMITTED], all of which are mistakes easily made in copying records.
These mistakes occurred before Pan Ku compiled his History.
In other cases, slighter or greater changes are necessary. They have
been noted in the appendices dealing with those eclipses. Altogether the
dates of thirteen eclipses were rectified with a considerable degree of
probability; those of 192, 176, 161, 149, 145, 141, 136, 135, 123, 108, 35,
1 B.C., and A.D. 6. The eclipses of 201, 151, and 155 also present
difficulties.
12. The calendars of correspondences between Chinese and European
dates are essentially correct. Hoang, who prepared the best of the
calendars dealing with this period, based his tables largely on previous
Chinese studies and partly on the correctly recorded eclipses, as is quite
proper. He also published a table of Chinese eclipses, indicating the correspondence
between astronomically calculated and Chinese dates, which
he took as the basis for his calendar. In those eclipses for which I have
been able to identify the original of a now incorrect date, and in which
the correct date was unknown to Hoang, it is possible to test Hoang's
calendar. In every case it is shown to be reliable (within close limits)
for the Han period.
The most interesting case is the eclipse of 96, in which a change in the
intercalary month from one year to the next (which is required by a
contemporary calendar for this year discovered by Stein in the desert;
cf. Chavannes, Documents chinois, p. 71) furnishes, unknown to Hoang, a
date from his calendar correct within one day to that obtained from
astronomical calculation. Thus modern science justifies Chinese calendrical
calculations.
There are however slight discrepancies. These never amount to more
than three days (except for the intercalary month mentioned above), so
that the essential accuracy of Hoang's table is maintained. More recent
in the text by two months, and is said to have occurred on the first day
of the month, both Hoang and Chen Yuan's Comparative Daily Calendar
(Chung-hsi-hui Jih-li) equate the actual date with the last day of the
month, so that both these calendars seem to be a day in error here. Because
of inaccuracies in Han calculations, it is quite possible that months
which our present calendars calculate as having 29 days actually had 30
days, so that modern calendrical computations may in some years be a
few days in error. Such seems actually to have been the case. Hoang's
calendar requires minor reworking.
13. In 37 cases, the position of the sun at the time of a solar eclipse
is given. By the use of Neugebauer's Sterntafeln, the positions of the
stars mentioned in the Chinese sources have been calculated for the date
of these eclipses. The comparison of these records with the calculated
position of the sun does not furnish any convincing proof that these
positions were the result of any observation. In partial eclipses, the stars
could not have been observed; almost all of these eclipses were observed
as partial. For the total eclipse of 181, when the stars could have been
observed, the position is 14° in error. For erroneously dated eclipses, the
position, if given, is grossly in error, and corresponds more to the (erroneous)
date than to the actual position of the sun at the time of the
actual eclipse. For the five eclipses whose dates are corrected and in
which positions are given, the errors in the dates are 3 yrs. 9 mo., 3 yrs.
4 mo., 1 yr. 7 mo., 10 mo., and 1 yr. 8 mo., while the errors in the position
are 103°, 130°, 66°, and 105° respectively. Towards the end of the
Former Han period, these positions are no longer given exactly in degrees,
only the constellation being given. It looks as though someone had
calculated the position of the sun from the date in the calendar at some
time towards the end of the Former Han period, possibly about 27 B.C.
(Liu Hsiang?), at which time the dates of many eclipses were already
in error.
Yet more of the positions are fairly correct. Of the 37 eclipses for
which positions are given, 24 are correct to 8° or less in R.A.; seven more
are in error only 10 to 14°. (Since Chinese astronomical observations
were always made with reference to the equator, not the ecliptic, celestial
positions are reduced to right ascension for purposes of comparison.)
The other six are grossly in error, from 42° to 105°. These are the
eclipses of 201, 192, 176, 161, 141, and 80. The first five of these are
incorrectly dated in the HS. For the others whose dates are correct,
there possibly has been some corruption in the original names of the
Chinese constellations.
These positions cannot have much significence and may be neglected.
Their use in Han times was astrological; the various parts of the sky were
taken to correspond to various localities on earth, hence an eclipse in a
certain part of the sky indicated something in the corresponding locality
on earth. It is possible that the heavenly location of the eclipse was
falsified in order to make the eclipse interpret some earthly event. In
however only six cases in the whole period are we given an interpretation
of the eclipse in terms of its heavenly location. Much more common
was an interpretation in terms of its month or day. Of the eclipses whose
location is grossly erroneous, only those of 201 and 141 were interpreted
in terms of their location. Hence it is not likely that many of the erroneous
heavenly locations were deliberate falsifications.
In conclusion: The outstanding impression left by the Chinese recordings
of eclipses in the Former Han period is their high degree of fidelity
to fact. The Chinese were not to any great extent interested in fabricating
eclipses as portents and it was dangerous to do so. They had not
yet begun to predict eclipses. They watched for eclipses, at times with
great pertinacity, and succeeded in observing eclipses that were quite
small and required the use of special means to be seen. It is but natural
that the original records should have suffered errors of transmission; as a
whole they are surprisingly correct. This fact constitutes an unimpeachable
testimony to the fidelity of the HS to fact. (Reproduced by
permission and with alterations from Osiris, vol. 5 [1938], pp. 499-522.)
The data for overcast days are for the years 1924-1936 and have been very kindly
reported to me by Fr. E. Gherzi, S.J., Director of the Siccawei Observatory.
A. Pogo, "Additions and Corrections to Oppolzer's Canon der Mondfinsternisse," the
Astronomical Journal, 1938, no. 1083.
The visibility of these eclipses has been computed by the method discussed in HFHD
I: app. III. Both P. Hoang, Catalogue des éclipses de soleil et de lune relatées dans les
documents chinois et collationées avec le Canon de Th. Ritter v. Oppolzer, "Variétés sinologiques,"
no. 56, and Chu Wen-hsin, Li-tai Jih-shih K'ao are not altogether reliable, since
they do not discuss these eclipses in detail and sometimes list an eclipse that was invisible
in China as the one referred to by the Chinese historian.
In dating these eclipses, capital roman letters refer to the year of a reign or year-period,
small roman letters to the (lunar) month, and arabic numbers to the day of the
month. European dates are given by the Julian system, as in Oppolzer, but years are
B.C., not astronomical years. (Hoang uses the Gregorian calendar for dates B.C., but
the Julian for the first millennium A.D.) In references, arabic figures followed by a colon
denote chapters of the HS, app. denotes appendices of those chapters, and small roman
numbers particular eclipses in those appendices.
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