Astronomy Explained Upon Sir Isaac Newton's Principles: And made easy to those who have not studied mathematicsFerguson, James
Science
Astronomy Explained Upon Sir Isaac Newton's Principles: And made easy to those who have not studied mathematics
Ferguson, James
Astronomy -- Early works to 1800
291. To be a little more particular, when the Ascending Node is in
Aries, the Angle is only 9-2/3 degrees on the parallel of _London_ when
Aries rises. But when the Descending Node comes to Aries, the Angle is
20-1/3 degrees; this occasions as great a difference of the Moon’s
rising in the same Signs every 9 years, on the parallel of _London_, as
there would be on two parallels 10-2/3 degrees from one another, if the
Moon’s course were in the Ecliptic. The following Table shews how much
the obliquity of the Moon’s Orbit affects her rising and setting on the
parallel of _London_ from the 12th to the 18th day of her age; supposing
her to be Full at the autumnal Equinox; and then, either in the
Ascending Node, highest part of her Orbit, Descending Node, or lowest
part of her Orbit. _M_ signifies morning, _A_ afternoon; and the line at
the foot of the Table shews a week’s difference in rising and setting.
+--------+---------------+---------------+---------------+---------------+
| | Full in her | In the | Full in her | In the lowest |
| | Ascending | highest part | Descending | part of her |
| | node. | of her Orbit. | node. | Orbit. |
| Moon’s +---------------+-------+-------+-------+-------+-------+-------+
| Age | Rises | Sets | Rises | Sets | Rises | Sets | Rises | Sets |
| | at | at | at | at | at | at | at | at |
| | H. M. | H. M. | H. M. | H. M. | H. M. | H. M. | H. M. | H. M. |
+--------+-------+-------+-------+-------+-------+-------+-------+-------+
| | _A_ | _M_ | _A_ | _M_ | _A_ | _M_ | _A_ | _M_ |
| 12 | 5 15 | 3 20 | 4 30 | 3 15 | 4 32 | 3 40 | 5 16 | 3 0 |
| 13 | 5 32 | 4 25 | 4 50 | 4 45 | 5 15 | 4 20 | 6 0 | 4 15 |
| 14 | 5 48 | 5 30 | 5 15 | 6 0 | 5 45 | 5 40 | 6 20 | 5 28 |
| 15 | 6 5 | 7 0 | 5 42 | 7 20 | 6 15 | 6 56 | 6 45 | 6 32 |
| 16 | 6 20 | 8 15 | 6 2 | 8 35 | 6 46 | 8 0 | 7 8 | 7 45 |
| 17 | 6 36 | 9 12 | 6 26 | 9 45 | 7 18 | 9 15 | 7 30 | 9 15 |
| 18 | 6 54 | 10 30 | 7 0 | 10 40 | 8 0 | 10 20 | 7 52 | 10 0 |
+--------+-------+-------+-------+-------+-------+-------+-------+-------+
| Dif. | 1 39 | 7 10 | 2 30 | 7 25 | 3 28 | 6 40 | 2 36 | 7 0 |
+--------+-------+-------+-------+-------+-------+-------+-------+-------+
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