Since all the stars which pass between the North Pole and the horizon cannot set, all their apparent movements will take place above the horizon. All the stars between the horizon and the South Pole will never rise. Hence, stars within the distance of 25° from the North Pole will never set at Thebes, and those stars within 25° of the South Pole will never be visible there. At any place the latitude and the elevation of the pole are the same. It so happens that many of those places with which archæologists have to do in studying the history of early peoples--Chaldæa, Egypt, Babylonia, &c.--are in low middle latitudes, therefore we have to deal with bodies in the skies which do set and bodies which do not, and the elevation of the pole is neither very great nor very small. But although in each different latitude the inclination of the equator to the horizon as well as the elevation of the pole will vary, there will be a strict relationship between the inclination of the equator at each place and the elevation of the pole. Except at the poles themselves the equator will cut the horizon due east and due west; therefore every celestial body to the north of the celestial equator which rises and sets will cut the horizon between the east and west point and the north point; those bodies which do not rise will of course not cut the horizon at all. The stars near the equator, and the sun, in such a latitude as that of Thebes, will appear to rise or set at no very considerable angle from the vertical; but when we deal with stars very near to the north or south points of the horizon they will seem to skim along the horizon instead of rising directly. * * * * * We now pass on to Stonehenge. To represent the new condition the axis of the globe will now require to be inclined 51° to the horizon. The number of northern stars which do not set and of southern stars which do not rise will be much greater than at Thebes. The most northern and southern stars visible will in their movement hug the horizon more closely than was observed under the Thebes condition. The sun, both at Thebes and Stonehenge, since it moves among the stars from 23¹⁄₂° N. to 23¹⁄₂° S. each year, will change its place of rising and setting at different times of the year. Now it will at once be obvious that there must be a strict law connecting the position of a star with its place of rising or setting. Stars at the same distance from the celestial pole or equator will rise or set at the same point of the horizon, and if a star does not change its place in the heavens it will always rise or set in the same place. The sun as it changes its position each day, in its swing N. and S. of the equator, will rise and set on any day in the same place as a star which permanently has the same distance from the equator as that temporarily occupied by the sun.