of the horizon. The Pole Star is that around which things revolve; it is the central point of a thing. It is a very faint star, situated to the northeast of us in al-Qassim. The scholars say that only someone with exceptionally sharp eyesight can see it, and then only on nights without moonlight, when the sky is clear. (1) Yet it has a conspicuous and readily visible neighboring star by which it may be identified: al-Jady. Al-Jady is close to it. For this reason, some people suppose that al-Jady is fixed and does not change, but this is not so. Rather, al-Jady moves slightly, though its movement is not perceptible because of its proximity to the Pole Star. The Pole Star itself, however, neither changes nor moves, like the pivot of a millstone. When the millstone revolves, what is near its pivot moves in a very slight and almost imperceptible circle; the nearer it is, the less noticeable its movement. What is farther away, on the other hand, moves in a wide and evident circle. The stars relative to the Pole Star are likewise: whatever is close to it moves in a very slight orbit—so much so that some people think it does not move—whereas what is distant from it moves in a large and obvious orbit.

I shall give you the example of the Greater and Lesser Dippers, which consist of seven large stars and seven small stars. At one end of the Lesser Dipper is al-Jady, and at the other are the two stars called al-Farqadān, concerning which the poet said: “The two Farqads of the sky shall never part.” They never set. We see them revolving: at times al-Farqadān are in the south and al-Jady is in the north, while at other times al-Farqadān are in the north and al-Jady is in the south; it does not set. As for the Greater Dipper, it does set, but scarcely an hour or an hour and a half passes before it rises.