Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s2.t90.3

v2.c12.s2.t90.3

In the Kali year 4535 (i.e. Śaka 1356), he compiled a tantra work, named ‘Cāndramān.’ It follows the modern Sūrya Siddhānta. There is a copy of this work in the Government Library Vārānasī. It explains only the methods of calculating mean and true places of planets. It contains nearly 200 verses. The mean positions in it have been calculated from the number of lunar months. But the solar reckoning too appears to have been included in it. Gaṅgādhara used to reside ir the city of Sagar, situated between the rivers Kṛṣṇāveṇi on one side and Bhīmarathī on the other, both of them lying to the west of Śrī Śaila mountain, which is situated on the prime (Ujjayinī) meridian. He was a Brāhmaṇa, belonging to Jamadagnya gotra. The names of his ancestors, from his father backwards were Candrabhaṭa, Bhaṭṭārya and Viṭṭhal. The astronomer, Śrī Candal, was born in this very family. Gaṅgādhara was a follower of the Sūrya Siddhānta. He was in the good graces of the king of Vidyāpur. As “Candramāna-Tantra” was very difficult to understand, his son Viśwanātha recast the work into easily intelligible verses. Viśwanātha’s date is not given.