Page:Philosophical Transactions - Volume 004.djvu/222

From Wikisource
Jump to navigation Jump to search
There was a problem when proofreading this page.

(1109)

At the middle of this Stellar Eclipse the Moons Center is but 20 sec. more to the South than the Star; so that, if the Libration of then Moon be known, the protraction of the States way in this Appearance will be facile. And this Phœnomenon is highly worth our strictest Observations; for, the Moon being almost in her Mean distance (where there is no great difference among Astronomers about her primary æquations) we may the more securely judge of her second inæqualities, and perhaps discover a third, which may promote the Moon, and accelerate the times in this Appearance. If diligent heed be given to the times of the sub-ingress and emersion of the Star, and with what Spots on the Moons face it keeps in a right line, we may be well assisted, by the obserued Mora to judge of her Diameter; for I question not, but her Apparent Horary Motion, may, with some little trouble, be exactly enough investigated either from the Wingian or the Caroline Tables,

IV. March 24. h. 15. 35 m. P. M. by the Ephemerides, the Moon will be in the same Longit. with the fore mention'd Star in ala Virg; with almost 2 degrees North-Latitude: whence at first I expected an Occultation; but upon a better Examen I find the Caroline Tables only present a Transit, as I shall prove by this Calculus, framed to the Meridian and Latitude of Derby: by which at 15 h. 42 m. 24 sec. P. M.

s. d. m. sec.

The Moons Mean Anomaly is 0 15 10 37

Her true place ♎︎ 0 5 33

The Argument of Latitude 5 6 38 46

The Moons true Latitude North 1 59 16

Her Horizontal Parallax 52 49

Her Horizontal Semi-diameter 14 17

The Suns Right Ascension 13 28

The Right Ascension of the Mid-heaven 249 4

The Mid-heaven ♐︎ 10 41

The Horoscope ♒︎ 12 31

The Angle Occident 16 58The