The Book of Stars: Being a Simple Explanation of the Stars and Their Uses to Boy Life

CHAPTER I. How to Find the North Star

HOW TO FIND THE NORTH STAR

If you want to know something about the stars which will be helpful as well as entertaining, the first thing you should do is to be able to find the North Star.

The North Star is taken as a starting point in the sky for two very good reasons: first, of all the thousands of stars which the eye can see, it moves the least; and second, it is north from any place on the Earth’s surface from which it can be seen.

It must be plain then that this star is the most important one of all to us, for by its friendly light we can easily tell the points of the compass, though we may be lost in an unknown land or shipwrecked on a strange sea. That is, of course, we can easily find the points of the compass if we have first learned how to find the North Star.

=How to Make a Star Finder.=—To find the North Star for the first time is a very easy matter if the simple directions given below for making and using a star chart, or star finder, are followed.

Get a smooth pine board, about 16 inches wide, 20 inches long and ⅞ inch thick; make two cleats of wood, each of which is 1 inch wide, 12 inches long and ½ inch thick, and screw these to the board near the ends and on the same side, to prevent the board from warping, as shown in Fig. 1. If a drawing board of any size is at hand, it will serve the purpose just as well as a homemade board.

The next thing to do is to obtain a sheet of cardboard about 12 by 16 inches and cover one side of it with a dull black paint; when the paint is thoroughly dry lay it, black side up, on the smooth side of the board.

From another sheet of white cardboard cut out seven stars, about the size and shape shown in Fig. 2, and cut out another star nearly twice as large, to represent the North Star.

Now place the white stars on the black surface of the cardboard in the positions shown in Fig. 3, using the smaller stars to form the outline of the Big Dipper and the large star for the North Star.

When all of the stars have been properly arranged, fasten them to the black cardboard with a bit of glue or mucilage. Push a thumb tack, or a pin, through the center of the large star, which is the North Star, and well into the board, so that the chart, or star map, can be turned round on the board with the North Star as its axis. When this is done your star finder is complete.

=Finding the North Star.=—All being in readiness, take this chart, or star finder, out-of-doors some evening when the seeing is good and all the stars in the northern sky are shining brightly, and face about north, holding the starboard in front of you, as shown in Fig. 4.

Usually the direction of north is well known, and yet there are some places where the streets and roads do not run due north and south, and for this reason it is sometimes hard to tell exactly which way is north. In such a place either use a compass to get your bearing, or, if you haven’t a compass, face about as nearly north as you know how.

(Position of Big Dipper in Autumn.)]

Having looked at your star chart carefully raise your eyes from the board until they are in a line with the northern horizon, that is, the line where the earth and the sky seem to meet. Keep on raising your eyes in a straight line until they reach a group of stars, which is about 40 degrees above the horizon. (See Fig. 98.) The line for sighting the North Star is shown in Fig. 5.

All the stars of this group are very faint except one and this particular star will stand out bright, distinct and alone, for the other two stars of the same group which can be plainly seen are not very close to it. The star you have found is the North Star, or Pole Star, or to give it its proper name Polaris (pronounced Po-la´-ris).

To make sure you have not mistaken some other star for the North Star it will be a good idea to prove your find. Search around in the northern sky a little and you will see a group of seven bright stars fixed in the sky just as the cardboard stars are fixed on the black surface of your chart, and which are shown in Figs. 4 and 5.

=The Big Dipper.=—This group of seven stars is called the Big Dipper because if a broken line joined all the stars together a very good figure of a big dipper would be formed. A group of stars is called a constellation, and this constellation is shown as we see it in Fig. 6, and as the ancient shepherds and sailors pictured it in Fig. 7.

In England this group of stars, or constellation, is sometimes called the Plough, for our friends across the pond see in it the likeness of a plough as well as of a dipper. It is also called the Great Bear the world over after the ancient name given it, but it requires some stretch of the imagination to liken it to that nubbly short-tailed animal.

All these fancy names were given this great group of stars long before the birth of Christ and by these names the constellation is still familiarly called. Astronomers of the present time also call this constellation the Great Bear, but they say it in Latin and so it becomes Ursa Major, which is a very high toned and scholastic sounding word. But the Big Dipper is a name that is good enough for all ordinary purposes and so we’ll use it.

The stars forming the Big Dipper stand out so bright and clear in the northern sky that you won’t have the slightest trouble in finding it, especially if you have the star finder at hand to help you.

In using the star finder there is one thing you should keep well in mind and that is that the Big Dipper as we see it turns round the North Star, like the hands of a clock, but in the opposite direction. That is, the Big Dipper, when below the North Star, seems to turn round the North Star from left to right.

In a word the North Star forms one end of the axis round which not only the Big Dipper but the whole starry heavens seem to revolve as though they were fastened to the spokes of a great wheel. This is the way it seems to us. As a matter of fact, though, all the stars are fixed in their positions in the sky, and the reason they seem to revolve round the North Star is because the Earth from which we see the stars turns round instead.

By looking at the drawing shown in Fig. 8, it will be seen that the north pole of our Earth is directly under the North Star,—hence the name Pole Star—and that if we could draw a line through the center of the Earth from the south pole to the north pole and extend the line far enough, or produce it as it is called, it would finally meet the North Star.

Let us take, now, another star, called the Dog Star—its real name is Sirius (pronounced Sir´-i-us)—which is not far from a line with and overhead of the Earth’s equator; suppose we are some place on the earth where we can see both the North Star and the Dog Star at the same time, and keeping in mind that the Earth is turning round on its axis; it must be plain, then, that though both of these stars are fixed in the sky and never change their positions we on the Earth will turn away from the Dog Star until the Earth has turned half way round, but we will not turn away from the North Star.

The eye, however, is easily deceived; for example, if we are on a moving train nearby objects, such as houses, trees, etc., will seem to be moving in the opposite direction to which we are going while we seem to be standing perfectly still. The illusion is much more complete when we are seeing the stars, for the motion of the Earth as it spins on its axis and shoots round the Sun in its orbit is so steady that we cannot notice it; for this reason it seems as if it is the stars which are moving and that we are standing still.

It is easy to understand now why the Big Dipper, and all the other stars, seem to move in great circles round the North Star as well as why the Big Dipper marked with cardboard stars on your chart may not have the same relative position to the horizon as the Big Dipper of real stars in the northern sky, when you view them together as in Fig. 4.

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