Twenty-eight days; the same length of time as her spin. 7. How long is the Moon’s day? About one fortnight of Earth-time. 8. How long is the Moon’s night? About another fortnight. 9. Does the Sun shine on all parts of the Moon? On all parts in turn, as the Moon slowly spins round. 10. Do we see all parts of the Moon? We see only one side, because, as the Moon spins, she journeys round the Earth just so fast as to keep one face always in our direction. 11. What is meant by Full Moon? At Full Moon the Earth is between Sun and Moon, and we have our best view of the full round face of the Moon. 12. Is the Earth exactly between? Not quite, or she would cut off the sunlight from the Moon. 13. What is New Moon? At New Moon the Moon is between Earth and Sun, so that her bright side is away from us and we cannot see her at all. 14. Tell me about the First and Third Quarters. The Moon is then at the side of the Earth, half-way between New and Full. Half only of her bright side is towards us and we see her as “Half Moon.” 15. What is a Lunar Month? A month of four weeks--the time of the Moon’s changes. CHAPTER VII. THE MOON THROUGH A TELESCOPE. You know how the Moon looks, seen only with our own eyes--a bright round ball, some would say a bright round plate, with odd gray markings which might mean anything. This is about all that can be learned without the help of a telescope. But with the help of a telescope much more can be found out as to our little sister-world. For a very long while there were no telescopes. Galileo, a famous man, who lived nearly three hundred years ago, was the first who ever made a telescope. Since his time men have learned to make far bigger and better ones; but it was he who discovered how to make one at all. The Moon, as you know, is really about 240,000 miles away. A good telescope, such as one may often see, lessens that distance to only one thousand or perhaps to five hundred miles. One enormous telescope in California brings the Moon to less than one hundred miles off--some even say to not much more than fifty miles. You must not suppose this to mean that the telescope pulls the Moon herself nearer. A tube on earth cannot reach forth and drag towards us a far-off world in the sky. Did you ever hear of the Irishman who was allowed to look through a telescope at a church in the distance, and who declared afterwards that the church had been brought so near he could hear the organ play! But this is just what a telescope is _not_ able to do. It does not bring a church nearer. It does not bring the Moon nearer. It only makes our eyes able to see _as if_ the church or the Moon were nearer. That is all. It gathers up a great deal more moonlight than our eyes could collect, and so it gives us a larger and clearer view of the Moon from which the light comes.