_The Calculation of New and Full Moons and Eclipses. The geometrical
Construction of Solar and Lunar Eclipses. The examination of antient
Eclipses._
353. To construct an Eclipse of the Sun, we must collect these ten
Elements or Requisites from the following Astronomical Tables.
[Sidenote: Requisites for a solar Eclipse.]
I. The true time of conjunction of the Sun and Moon: to know at what
conjunctions the Sun must be eclipsed; and to the times of those
conjunctions,
II. The Moon’s horizontal parallax, or angle which the semi-diameter of
the Earth subtends as seen from the Moon.
III. The Sun’s true place, and distance from the solstitial colure to
which he is then nearest, either in coming to it or going from it.