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
365. PRECEPT. Enter the XVth Table with the Sun’s Anomaly, and thereby
take out his Semi-diameter; and in the same manner take out the Moon’s
Semi-diameter by her Anomaly. The former of which for the above time
will be found to be 16ʹ 6ʺ; the latter 14ʹ 58ʺ.
_To find the Semi-diameter of the Penumbra._
[Sidenote: Tenth Element.]
366. PRECEPT. Add the Sun’s semi-diameter to the Moon’s, and their Sum
will be the Semi-diameter of the Penumbra; namely, at the above time 31ʹ
4ʺ.
[Sidenote: Pl. XII.]
366. Having found the proper Elements or Requisites for the Sun’s
Eclipse _April 1, 1764_, and intending to project this Eclipse
Geometrically, we shall now collect them under the eye, that they may be
the more readily found as they are wanted in order for the Projection.
[Sidenote: The proper Elements collected.]
D H M
367. I. The true time of Conj. or New Moon _April_ 1 10 25
° ʹ ʺ
II. The Earth’s Semi-Disc, which is equal to the
Moon’s Horizontal Parallax 55ʹ 7ʺ diminished by
the Sun’s Horizontal Parallax which is always 10ʺ 0 54 57
III. The Sun’s distance from the nearest Solstice,
_viz._ ♋ 77 51 0
IV. The Sun’s Declination, North 4 48 54
V. The Angle of the Moon’s vis. path with the
Eclipt. 5 38 0
VI. The Moon’s true Latitude, North Ascending 40 9
VII. The Moon’s true Horary Motion from the Sun 27 50
VIII. The Sun’s Semi-diameter 16 6
IX. The Moon’s Semi-diameter 14 58
X. The Semi-diameter of the Penumbra 31 4
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account