Jyotihshastra: Astral and Mathematical Literature c3.42

c3.42

The first section of the Kātyāyana, which consists of ninety *sūtras*, is divided into six *kaṇḍikās*. It teaches, in language often identical with or similar to the Āpastamba’s, the geometrical propositions (including the first detailed instructions for determining the cardinal directions from the shadows cast by a gnomon), the measures employed in constructing the altars, and their spatial relationships. The second section, which consists of more than 40 verses, repeats some of the material given in the *sūtra* section, and adds to it descriptions of the rope, the gnomon, and the expert builder of altars. There are commentaries on the Kātyāyana by Karka,²⁷ who wrote before 1260/1270 (Karkabhāṣya); by Rāma Vājapeyin, who composed three of them²⁸ (the *Śulbavārttika*, a metrical gloss on the Kātyāyana and on the Karkabhāṣya, in 1434; the Śulbavārttikaṭīkā, a commentary on the preceding; and the Śulbasūtravṛtti, a prose commentary based on the Śulbavārttika) at Naimiṣa in Uttarapradeśa; and by Mahīdhara²⁹ at Vārāṇasī in 1590 (Śulbasūtravivaraṇa).