ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

civil days in a Mahāyuga according to Brahmagupta as referred to in the Khaṇḍakhādyaka. Again, the same stanza tells us to subtract 20 and 4 respec- tively from the revolutions of Mercury and Jupiter, and we arrive at the figures 17,937,000 and 364, 220, which are the revolutions of Mercury and Jupiter in a Mahāyuga according to Brahma- gupta as given in the Khaṇḍakhādyaka. Again we can compare the figures for the diameters of the Earth, the Sun and the Moon given in the Mahābhāskarīya, in the present day Sūrya-siddhānta and the Āryabhaṭīya. Diameter Mahābhāskarīya Modern. Āryabhaṭīya of Sūrya-siddhānta Earth 1,600 yojanas 1,600 yojanas 1,050, yojanas Sun 6,480 6,500 4,410 Moon 480 480 315 Then in stanza 24, we are given the distances of the Sun and the Moon as 689, 358 and 51, 566 yojanas respectively. The same figures are worked out by Lalla according to the Āryabhaṭīya and quoted in the Śiṣyadhwṛddhida (IV.3.4) and they come to be 459,585 and 34,377. The stanza 25 states the longitudes of the aphelia of planets these figures tally with the corresponding figures given by Brah- magupta in the Khaṇḍakhādyaka : Longitude of aphelion of Jupiter 160°, of Venus 80°, of Saturn 240°, of Mars 110° and of Mercury 220°. Similarly the stanza 26 gives the peripheries of planets’ epicycle of apsis, which also is in concordance with the values given by Brahmagupta : Periphery of epicycle of apsis of Jupiter 32°, of Venus 14°, of Saturn 60°, of Mars 70° and of Merury 28°. In the stanza 27 of the Mahābhāskarīya, we have the dimensions of the epicycles of conjunction for planets; these figures are also the same as given by Brahmagupta : Epicycles of conjuction for Jupiter 72°, for Venus 260°, for Saturn 40°, for Mars 234° and for Mercury 132°. In the stanza 28, we have the Sun’s epicycle having a periphery of 14° and the Moon’s epicycle 31° ; the longitudes of