When the Earth is at _A_ the New Moon is at _a_; and in the seven days that the Earth describes the curve _1 2 3 4 5 6 7_, the Moon in accompanying the Earth describes the curve _ab_; and is in her first Quarter at _b_ when the Earth is at _B_. As the Earth describes the curve _B 8 9 10 11 12 13 14_ the Moon describes the curve _bc_; and is opposite to the Sun at _c_, when the Earth is at _C_. Whilst the Earth describes the curve _C 15 16 17 18 19 20 21 22_ the Moon describes the curve _cd_; and is in her third Quarter at _d_ when the Earth is at _D_. Once more, whilst the Earth describes the curve _D 23 24 25 26 27 28 29_ the Moon describes the curve _de_; and is again in conjunction at _e_ with the Sun when the Earth is at _E_, between the 29th and 30th day of the Moon’s age, accounted by the numeral Figures from the New Moon at _A_. In describing the curve _abcde_, the Moon goes round the progressive Earth as really as if she had kept in the dotted Circle _A_, and the Earth continued immoveable in the center of that Circle. [Sidenote: The Moon’s motion always concave towards the Sun.] And thus we see, that although the Moon goes round the Earth in a Circle, with respect to the Earth’s center, her real path in the Heavens is not very different in appearance from the Earth’s path. To shew that the Moon’s path is concave to the Sun, even at the time of Change, it is carried on a little farther into a second Lunation, as to _f_. [Sidenote: How her motion is alternately retarded and accelerated.]