Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s5.19

v2.c12.s5.19

The orbits of planets should, if necessary be tied in this globe separately with circles of aphelia and perihelia. This globe has been described to show the construction of the Universe. In fact it is very difficult to tie together all these rings, and it is still more difficult to take observations with their help. for instance, if the starry globe is fixed inside a ‘khagola’, it will be difficult to fix the observation circle. It cannot be believed that Bhāskarācārya and others could not realize these difficulties. It is clear that at the time of taking actual observations only the most necessary rings should be made use of, and observation can thus be taken. We had no instrument of the type of astrolabe designed by Hipparchus; but this speaks for the independence of our works in this respect. The above globe can be used in place of the astrolabe, Brahmagupta, Lalla, and both the Āryabhaṭas have recommended the construction of the same kind of globe. The globe described by the First Āryabhaṭa is less complicated than this.