Bering was in Eastern Siberia, Kamchatka and the adjacent waters in
1728 and 1729. Could he have observed a lunar eclipse there at that
time?
According to the ephemeris of Manfred[1] published at Bonn in 1725
there were two partial eclipses of the moon visible in Europe in 1728,
and two total eclipses of the moon in 1729.
[Footnote 1: Manfredius (Eustachius). Novissimae ephemerides motuum
coelestium e Cassinianis tabulis ad meridianum Bononiae supputatae
auctoribus Eustachio Manfredio (etc.) Tomus 1. ex anno 1726 in annum
1737 (etc.) 4° _Bononiae_, MDCCXXV.]
In regard to these four eclipses the ephemeris furnishes the following
data:
| 1728, | 1728, | 1729, | 1729,
| Feb. 24. | Aug. 19. | Feb. 13. | Aug. 8.
-------------------+-----------+-----------+-----------+-----------
Eclipse begins | 18^h 32^m | 4^h 07^m | 7^h 45^m | 12^h 02^m
Total immersion | -- -- | -- -- | 8 46 | 13 02
Middle of eclipse | 20 0 | 5 35 | 9 35 | 13 52
Emersion begins | -- -- | -- -- | 10 24 | 14 42
Eclipse ends | 21 29 | 7 03 | 11 25 | 15 42
-------------------+-----------+-----------+-----------+-----------
Digits eclipsed | 9 51 S.| 7 45 N.| 19 46 | 19 44 S.
Sun rises | 18 36 | -- -- | -- -- | -- --
Sun sets | -- -- | 6 49 | -- -- | -- --
Eclipse | Partial | Partial | Total | Total.
-------------------+-----------+-----------+-----------+-----------
Sun's declination | -9° 38' | +12° 42' | -13° 16' | +16° 09'
" hourly motion | + 0.9 | - 0.8 | + 0.8 | - 0.7
-------------------+-----------+-----------+-----------+-----------
In this table the calendar is Gregorian, the time is apparent or true
sun time, the day is reckoned from noon and the hours are counted
continuously through the entire 24.