EXAMPLE.

_To find the Sun’s true Place_ April _30th, A. D. 1757, at 18 minutes 40

seconds past 10 in the morning_.

+---------------------------------------------+-------------+-------------+

| | Sun’s Long. | Sun’s Anom. |

| The year next less than 1757 in the Table +-------------+-------------+

| is 1753, at the beginning of which, the | s ° ʹ ʺ | s ° ʹ |

| Sun’s mean Longitude from the beginning +-------------+-------------+

| of Aries, and his mean Anomaly, is | 9 10 16 52 | 6 1 38 |

| To which add his mean Mot. and Anom. for | | |

| four years to make 1757 | 0 0 1 49 | 11 29 58 |

| { _April_ | 2 28 42 30 | 2 28 42 |

| { days 29 | 0 28 35 2 | 0 28 35 |

| And likewise his mean Mot. and { hours 22 | 0 54 13 | 0 54 |

| Anom. for { min. 18 | 0 44 | 1 |

| { sec. 49 | 2 | 0 |

| | ----------- |-------------+

| Sun’s mean Longitude and Anomaly for the | | |

| given time is | 1 8 31 12 | 9 29 48 |

| To which add the Equation of the Sun’s | | |

| mean Place | 1 40 14 +-------------+

| | ----------- | Sun’s Eq. |

| And it gives his true Place, _viz._ | | 1° 40ʹ 14ʺ |

| ♉ Taurus 10° 11ʹ 26ʺ | 1 10 11 26 | |

+---------------------------------------------+-------------+-------------+

N. B. _In leap-years after_ February, _the Sun’s mean Motion and Anomaly

must be taken out for the day next after the given one._

361. _To calculate the Sun’s true Place for any time in a given year

before the first year of_ CHRIST: subtract the mean Motions and

Anomalies for the compleat hundreds next above the given year; to the

remainder add those for the residue of years, months, _&c._ and then

work in all respects as above taught.

Astronomy Explained Upon Sir Isaac Newton's Principles And made easy to those who have not studied mathematics · 第 210 / 275 题