Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s5.54

v2.c12.s5.54

*YANTRA RĀJA* :—There lived in Bhṛgupura an astronomer Madan Sūri by name. His disciple Mahendra Sūri compiled this work in Śaka 1292. There is at the beginning of the work a salutation to ‘sarvajña’ (i.e. the Knower of all things). From this it appears that this writer must have been a Jain. The work consists of five chapters viz. Gaṇita (mathematics), Yantraghaṭanā (principles of instrument making), Yantra racanā (construction of instruments), Yantrasādhanām (use of instrument), Yantra vicāraṇā (theory of instruments), and has in all 182 verses in it. MALAYENDU SŪRI has written a commentary on it, in which he says that Mahendra Sūri was the Head Astronomer at the Royal Court of Emperor FEROZE SHAH. The Samvat 1435 (Śaka 1300) has been adopted in many of the solved examples. In one case the Samvat 1427 has been taken and in another, Samvat 1447; and the commentator calls Mahendra Sūri his preceptor, This shows that he (Malayendu Sūri) was his direct disciple; and the date of compilation of the commentary also was about Śaka 1300. Sudhākara Dwivedī published this work at Vārānasī. The author observes in the very first chapter,