To find a constellation that is as far away from the North Star as Pegasus (pronounced Peg’-a-sus) is not an easy thing to do, at least the first time you try it, for while our chart is marked with a straight line the sky is like a great bowl and a line produced from the North Star to Pegasus will, in consequence, not be a straight line, but a curved line. However, with your star finder charted like the diagram shown in [Fig. 17] you will be able to locate Pegasus with very little effort.
After taking off all the stars from the cardboard surface, pin or paste the North Star to the lower left hand corner of the black surface of the cardboard and place the five stars of Cassiopeia in their proper positions. Now draw a line from the North Star through Cassiopeia just below the star marked β which is the Greek letter beta ([see Appendix C]) and produce, or extend that line until the edge of the cardboard is reached. On the extreme right hand end of this line set two stars, which we will also call pointer stars, and place two more stars above them so that a nearly perfect square will be formed as shown in [Fig. 17].
Fig. 17.—The Great Square of Pegasus.
To find Pegasus take the star chart out-of-doors, say some evening in November about 9 o’clock, for the Great Square will then be on the meridian, that is, on a line passing over your head and which runs north and south across the sky. This time, instead of looking down on the chart, as you did in finding the Big Dipper and Cassiopeia, turn the board bottom side up, as shown in [Fig. 18], but still keeping the cardboard North Star pointing north and the four stars of Pegasus pointing toward the south.
By looking over your chart into the sky and following an imaginary line with your eye from the North Star through Cassiopeia past the star β (beta) and lengthening this line toward the equator in the southern sky you will come upon four bright, white stars which form the Great Square of Pegasus and you have added another and fourth constellation to your list.
The practical value of knowing the mighty constellation of Pegasus is that you can always find the north, by means of its friendly stars, though the North Star, the Big and Little Dippers and Cassiopeia are hidden by clouds. To find the north you only have to wait until Pegasus gets very high in the sky and run an imaginary line through the pointer stars of Pegasus and produce it until it reaches the northern horizon.
Fig. 18.—Holding the Chart of Pegasus Overhead.
The Great Square of Pegasus was fancifully pictured by the ancients as a Flying Horse and, curiously enough, with only half a body at that, as shown in [Fig. 19]. To those who do not know the lore of the stars it is not so easy to see in the Great Square the fabled winged steed who still continues his flight through the sky just as he did when he was invented over four thousand years ago.