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

MODERN SŪRYA SIDDHĀNTA 69
Chapter Name of the Number
Chapter of verses Subject
XIII Vyatīpāta-viṣayāḥ 26 Armillary sphere and
astronomical instru-
ments
XIV — 28 Modes of reckoning
time
Total 500
From the contents of the Modern Sūryasiddhānta, it appe-
ars that its great author (or rather compiler, since this Siddhānta
has been existing much before he compiled this treatise) intends
giving a complete but brief account of the entire Indian astron-
omy. He has been careful enough to avoid controversies, and
he has omitted the methods occurring in other Siddhāntas and
Mahā-tantras as alternative rules. He describes only those
which are most important and of general nature. Part II of
the book dealing with cosmogony and geography etc.. is very
brief , a nd the entire subject has been summarised in three chap-
ters (Chapters XII to XIV). The Chapter on Astronomical
instruments (XIII) is sketchy and rather incomplete; the author
has given the names only of the instruments, as if the purpose
was to keep the details secret and guarded. The whole text of
the Sūryasiddhānta is finished in 500 verses (compare this with
the length of other Indian books on Astronomy: the Brāhmasph-
uṭasiddhānta 1008 verses, the Siddhānta-śekhara 890 verses and
Siddhānta-śiromaṇi proper 962 verses).
The Modern Sūryasiddhānta is a composition or compila-
tion of a period when the Āryabhaṭīyam and the Brāhmasphuṭa-
siddhānta had already become popular. This Sūryasiddhānta is
indebted to both these systems, though it has nowhere acknowledged
them in the Text. We shall refer to this matter later at an appro-
priate stage of our discussion.
It may casually be mentioned here that Alberuni has
ascribed the authorship of the Sūryasiddhānta to Lāṭadeva while
Munīśvara (603 A. D.) has ascribed it to Āryabhaṭa I. Though
there is little or no support to these views, it is not improbable,
that the works of Āryabhaṭa I and Lāṭadeva which followed mid-
night-day-reckoning were based on the Sūryasiddhānta prevalent
at the time. P. C. Senagupta on the other hand is of the opinion
that “ the old Sūryasiddhānta was made up-to-date by Varāhami-
hira by replacing the old constants in it by new ones from Ārya-