Astronomia Britannica exhibiting the doctrine of the sphere, and theory of the planets decimally by trigonometry, and by tables : fitted for the meridian of London ...
Newton, John, 1622-1678.
CHAP 27. To find the middle of the Eclipse or greatest darkenesse.
THe time of the true Conjunction or Opposition the most recei∣ved, is when the Sun and Moon are in one line perpendicular to the Ecliptique, to find this with the Moons true Latitude at the true opposition, enter the little Table of the difference of the true Conjunction or opposition from the greatest obscuration, and you shall find the difference with the title, which divide by the hourly motion of the Moon from the Sun, and the quotient according to the title, apply to the time of the true opposition; so have you the time of the greatest darkenesse, or middle obscuration.
Example.
| The Moons Latitude, North Descend. | . 51496 | |
| The difference adde | . 04489 | |
| Which divide by the hourly motion of the Moon | . 48121 | |
| Gives the difference in time to be added | . 09328 | |
| To the true opposition March 13. 15 | . 89814 | |
| So the middle of the Eclipse | 13. | 15h. 99142 |
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The Calculation of the forementioned Ecclipse according to the preceding directions.
| d. | ho. | |
| Meane opposition March | 13 | 6. 45639 |
| Interval Adde | 9. 35580 | |
| True opposition | 13. | 15. 97681 |
| True place of Sun | 5. 24194 | |
| Eccentrick place of the Moone | 185. 24190 | |
| Meane Anomaly of the Sun | 266. 79954 | |
| Meane Anomaly of the Moone | 35. 44378 | |
| True motion of Latitude | 174. 04881 | |
| True Latitude North descend. | . 51496 | |
| Reduction Adde | . 02398 | |
| Hourly motion of the Sun | . 04111 | |
| Hourly motion of the Moon | 0. 52232 | |
| Hourly motion of the Moon from the Sun | . 48121 | |
| Reduction in time Subt. | . 04983 | |
| True opposition corrected | 13 | 15. 92698 |
| Equation of time Subt. | . 02884 | |
| T•uest opposition | 13. | 15. 89814 |
| Horizontall Parallax of the Moone | . 94409 | |
| Semiangle of the Cone | . 23455 | |
| Semidiameter of the shadow | . 70954 | |
| Semidiameter of the Moone | . 26431 | |
| Sum of the Semidiameters | . 97385 | |
| Scruples deficient | . 45880 | |
| Digits eclipsed | 10. 4197 | |
| Scruples of incidence | . 82656 | |
| Time of incidence | 1. 71770 | |
| Beginning of the Eclipse | 13 | 14. 18044 |
| End of the Eclipse | 13 | 17. 61584 |
| The whole duration | 3. 43540 | |
| Latitude of the Moone at the beginning North D. | . 59223 | |
| Latitude of the Moone at the ending North D. | . 43746 | |
| Difference from the middle, Added | . 09328 | |
| The middle of the Eclipse | 13. 15 | . 99142 |
