The bright portion of the moon now grows larger and larger until, in about seven or eight days, we see it as it is shown in Figure 2. Then it is said to be in its first quarter. At this time the spots and various markings on its surface are generally seen very distinctly. For seven days the bright portion of the moon continues to grow larger and larger, and during a part of this time it presents the appearance shown in Figure 3. [Illustration: FIG. 2. FIRST QUARTER.] At last, after about fifteen days of active increase of bright surface the moon reaches that point where the sun shines directly upon the side presented to the earth, and then it is “full moon.” Of course it must, at this time, be on the side of the earth farthest from the sun so that the sun can shine on it, and at the same time, we can see it. [Illustration: FIG. 3. BETWEEN FIRST QUARTER AND FULL MOON.] Figure 4 is a small picture of the full moon. But the moon does not remain full very long, as many of us who delight in moonlight rambles, and boat-rides, know to our sorrow. It soon begins to wane, and then assumes very much the same forms that it presented when on the increase, with this difference; its lighted portion is always turned the other way. [Illustration: FIG. 4. THE FULL MOON.] It now rises later and later. When it was full it rose at about the time that the sun set, and set about sunrise. But now it rises later and later until at last it rises just before the sun, and is of course soon invisible in his brighter rays. Figures 5, 6 and 7 will give you an idea of the various phases assumed by the moon when in its wane, or decrease. [Illustration: FIG. 5. BETWEEN FULL MOON AND LAST QUARTER.] [Illustration: FIG. 6. LAST QUARTER.] [Illustration: FIG. 7. BETWEEN LAST QUARTER AND NEW MOON.] So now we have seen the moon in its various phases, which is nothing more than we can see in the heavens when the sky is clear, but it is better always to understand what we see. We should remember, then, that one half of the moon is always bright. When it is between us and the sun (not on an exact line, however, for that would make an eclipse of the sun) we cannot see it at all, and then we say “there is no moon to-night.” When it moves around so that we can see a little of the bright side, it is “new moon,” and when it gets around behind us, so to speak, so that we can see the sun shining full upon one side of it, it is “full moon.” If one of us could live upon that part of the surface of the moon that is always turned toward us, he could see the same changes taking place upon our planet as we see on the moon. There would be “new earth,” and “quarter earth,” and “full earth,” which last would be truly grand! Think of a bright orb of light in the heavens fourteen times larger than the full moon, and you will have an idea of how our earth would sometimes appear to observers on the moon,—were there any one there to see. A VOYAGE TO THE LOWER AMAZON.