"That's correct," said Uncle Henry, "and you want to notice that as Paul walks round the lamp and looks across it at the signs on the wall beyond it, the lamp seems to Paul to move from one picture to the next." This picture is drawn as if the ceiling of the room was taken off and you could look down on Paul walking around the lamp. [Illustration] When it is January first, Paul, representing the earth, is in the position marked A, nearest to the picture of _Gemini_ behind him, while the lamp, representing the sun, appears to him to be entering the sign of the Zodiac called _Sagittarius_, directly opposite across the room. Later, on April first, after three months, Paul, or the earth, has traveled a quarter of the way around the sun, has passed the pictures of _Cancer_ and _Leo_ on the wall behind him, and stands nearest _Virgo_ in the position marked B. The lamp has also seemed to move through a quarter circle, has passed through the signs of _Capricornus_ and _Aquarius_, and appears to Paul to be just entering the sign of _Pisces_, or the Fishes. In the same way the earth moves through a sign of the Zodiac every month and the sun, while really motionless, _appears_ to also travel through a sign every month. Of course we cannot see the sign or constellation, where the sun appears to be, at the same time we see the sun, for his brightness makes the stars invisible, but if we _could_ see the constellations by day, the sun would appear to travel from one sign of the Zodiac to the next every month. [Illustration] Here is a clock of the year which shows the earth at one end of the hand, the sun in the middle, and at the other end of the hand an arrow, which points to the sign of the Zodiac where the sun appears to be, and to the date when it seems to be there to an observer on the earth. Draw the hand with the earth-end in several different positions and you will see that the sun, if viewed from the earth, would appear to be in the sign of the Zodiac exactly opposite. When the children all understood the way the Zodiac divides the yearly path of the earth into twelve equal parts, Betty said, "I want to know why the geography globe at school always looks just as if it was going to tip over." Uncle Henry laughed. "If you think the geography globe looks unsteady because its axis of iron rod is on a slant, what will you think about the earth when I tell you that it spins around in just the same slanting position, with only an _imaginary_ line for axis?" "Does it really?" asked Betty. "Yes," said Uncle Henry, "and it spins so steadily in that slanting position that the north end of its imaginary axis always points toward the same place, a point very close to the north star, or _Polaris_ as it is called." "_Polaris_ is named for the North Pole, I suppose," said Peter.