01Five siddhantas in one book
He was the son of Adityadasa and was trained at Kapitthaka, he tells us, before settling in Avanti. The Pancha Siddhantika takes the Paulisha, Romaka, Vasishtha, Saura and Paitamaha siddhantas and sets out how each computes the planets, with 505 CE (Shaka 427) as the epoch from which its reckoning starts. Without it, much of what those older systems taught would be lost. He counts the Saura, the system of the Surya Siddhanta, as the most accurate.
02The Brihat Samhita
The Brihat Samhita runs to over a hundred chapters and reads like an encyclopaedia of the 6th century. It explains how to forecast rain from the signs of the months, how to find groundwater by the trees and termite mounds above it, how to choose a site and lay out a temple and an image, how to test gems, make a strong mortar (vajralepa), and judge horses, elephants and swords. His Brihat Jataka is still a standard text of Hindu horoscopy. The commentator Amaraja recorded that he died in 587 CE.
