At Full Moon _the Earth is between the Sun and the Moon_. On one side of our Earth is the Sun; on the other side is the Moon. The Sun shines full upon that side of the Moon which is turned towards us; and so we see the whole of her round bright face. We know that her farther side is in darkness, because it is turned away from the Sun: in almost pitch-darkness, for it has not even our Earth to light it up, being turned away from us also. It has only Stars on the farther side. I am speaking of when the Sun has set, and is below our horizon, so that we cannot see him, although his rays travel straight to the Moon. The Sun having set means only that the solid body of our Earth is between him and us. It does not interfere with his shining upon the Moon. If our Earth at Full Moon were _exactly_ between the Sun and the Moon, that would interfere with his shining upon her. More commonly, however, our Earth is not just in the line between, but only very nearly so. Thus we get the best possible view of the Moon’s round face. The Moon does not stay on one side of the Earth. She is always travelling round from one side to the other side of us. At another part of her monthly journey things are quite different. A fortnight after Full Moon we have _New Moon_. At Full Moon the Earth is between Sun and Moon; but at New Moon the Moon has come right round to the opposite side, and is _between the Sun and the Earth_. Not usually in the exact line between, so as to hide the Sun from us, but very nearly so. Then still the Moon has a bright round face; only we on Earth cannot see it. For her bright side is, as always, towards the Sun; and her _dark_ side is towards us. Just at first we cannot see the New Moon at all, for it is entirely dark. As she journeys on to one side we get a glimpse of a thin line of light shaped like a sickle; and this widens every day. It is while we see the sickle of light that we sometimes catch a glimpse of the dark side of the Moon, dimly lighted up by Earth-shine. [Illustration: _The Moon. Second quarter. 10½ days old._] When the Moon gets half-way back to where she was at Full Moon we are able to see _half_ of her bright face, and we call that the “First Quarter.” The other half of the bright face is still turned away from us, and half of the dark side is still towards us. We do not see the whole round face till she gains once more the place of Full Moon--after which, between Full Moon and New Moon, follows the Third Quarter, which is much the same as the First Quarter. You know that the rising and the setting of the Moon in our sky, by night or by day, are not real movements. They are only seeming movements, caused by our own Earth’s daily spinning on her axis.