Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s5.16.2

v2.c12.s5.16.2

While tying the circular rings, care should be taken to see that a portion of the stick is kept projecting and these ends should be passed into two tubes fixed in the celestial sphere whose construction is described later on. The ends of the polestick should point to the poles of the equator, so that the north end of the stick should be found to make an angle, equal to the latitude of the place, with the north pole of the equator lying in the celestial globe which is fixed clearly all round the ‘starry sphere’; and the ends of the pole stick should be so passed into tubes that, while the ‘khagoi’ (celestial sphere) would be kept fixed in position, the starry globe would freely rotate in it. The celestial globe should be so set as to envelope the starry globe. Its construction is as follows. Its circular rings should, of course, be larger in size than those of the starry globe. The ring representing the ‘samavṛtta’ (prime vertical) which passes through the zenith, nāḍir, and the east and west points, similarly the ring representing the meridian, as also the other rings representing the secondary directions—all these four rings should be of the same circumference. These should be tied to one another, so that each of them would pass above and below the others. The ring representing the plane of the horizon should be tied to them all, midway between them.