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

REFERENCE TO ROMAKA AND PAULIŚA SYSTEMS 55 sphuṭasiddhānta (I. 2) substantiates this view : The science of astronomy (or the calculations of heavenly bodies) in course of long duration became ineffective or erro- neous; this was revived by Brahmagupta, son of Jiṣṇu.¹ (BrSpSi. I.2). The system of astronomy which goes by the name Brahma (Brahmasiddhānta) has been handed down to us in three forms : (i) one is as treated by the Śākalya Saṁhitā, (ii) one as described in prose in the Viṣṇudharmottara Purāṇa, and (iii) the one des- cribed by Varāhamihira in the Pañcasiddhāntikā, which re- cognises the yuga of the duration of five years. Which of these three was accepted by Brahmagupta is not clear. But from the measures of the number of revolutions performed by a planet in a given period (graha-bhagaṇa) etc., it is clear that Brahmagupta acknowledges the system as propounded in the Viṣṇudharmottara Purāṇa. In his chapter "Tantra-parīkṣādhyāya or Dūṣaṇā- dhyāya, he contradicts the notions of the Vedāṅga Jyotiṣa which accepts the yuga of five years. We may further emphasize the fact that Brahmagupta has not clearly detailed out the errors to which the Brahma-siddhānta succumbed in course of time, and how these errors were eradi- cated by him. During the days of Brahmagupta, Romaka and Pauliśa systems were getting currency in this country. Reference to these two are found in the Brāhmasphuṭasiddhānta at several places as follows : ROMAK : I.13; XI.50; XXIV.3 PAULIŚA : XIV.45; XXIV.3 In fact, BrSpSi. XXIV.3, we find the line "Sūryendu-Puliśa- Romaka-Vasiṣṭha-Yavanādyaiḥ", where we have a reference to all the then existing systems : Sūrya-siddhānta, Indu-siddhānta, Puliśa-siddhānta, Vasiṣṭha-siddhānta, and other Yavana-siddhā- ntas. Just as the Sun is one, so the astronomical system is also one ; this is a different thing that calculations in different systems may vary according to different sunrises in different places. Brahmagupta refers at one place to Varāhamihira in BrSpSi. XXI.39, where he has been spoken of in connection with a list of

१. ब्रह्मोक्तं ग्रहगणितं महता कालेन यत् खिलीभूतम् । अभिधीयते स्फुटं तज्जिष्णुसुतब्रह्मगुप्तेन ॥ — BrSpSi. I. 2.