...must first be premised, that the Sun will always be vertical to that point of the Earth, where a right line drawn from the centre of the Sun to the centre of the Earth cuts the surface of the latter. Thus, "when the Earth is in the beginning of Capricorn, the Sun will...

...ecliptic, during a year, is called the Apparent Orbit of the sun. 18. A right line, conceived to be drawn from the centre of the sun to the centre of the earth, or to the centre of a planet, is called the Radius Vector of the earth or planet. A right line joining...

...small matter as 445,500, or 441,500, or 4,000 miles, which will be the differences, whether we work from the centre of the sun to the centre of the earth, or from disk to centre of one or other. We would be particular if we could, but we believe the point...

...the earth from the sun, being equal to half the axis AB*, consequently SE is 95 millions of miles.'f Though the motion of the earth in its orbit be not...D to B, be equal, then the areas, or spaces, ASE, SED, and DSB, will all be equal. The motion of the earth is sometimes rapid and sometimes slow in moving...

...drawn from its centre to the centre of the sun, is called the radius vector. 2. The radius vector, (or line drawn from the centre of the Sun to the centre of any Planet revolving around it,) describes equal areas in equal times. The nearer a planet is to the...

...illumination, is a great circle (6). It is evident that the plane of this circte will be perpendicular to a line drawn from the centre of the sun to the centre of the earth, called the radius vector. When the earth is in Libra at A, the sun will appear in Aries, his polar...

...sun,, observe the following laws : 1st. The areas described by the radius vector of a planet (or the line drawn from the centre of the sun to the centre of the planet), are as the times employed in describing them. 2d. The orbit of a planet is an ellipse of small...

...now passed out of the constellation Aries and is nearly at the beginning of Pisces; the line however drawn from the centre of the sun to the centre of the earth at the vernal equinox still bears the name of " the line drawn through the first point of Aries," and...

...one south of the equator is called the Tropic of Capricorn. TH E SEASO NS If we suppose a line to be drawn from the centre of the sun to the centre of the earth, it will meet the surface of the earth at a point just 90° distant from the circle limiting the enlightened...

...In this case, it is obvious that the plane of the circle of illumination would be perpendicular to a line drawn from the centre of the sun to the centre of the earth, " to which we suppose the sun's rays to be parallel; for in this position the axis represents that...