Brihat Samhita
अवनत्या अर्के ग्रासो दिग्ज्ञेया वलनयाअवनत्या च । तिथ्यवसानाद्वेला करणे कथितानि तानि मया ॥ ५-१८ ॥
The magnitude of the solar eclipse is determined by means of the moon’s parallax (in latitude); the points (on the disc) of the commencement and termination of the eclipse are determined by means of both parallax and angles; the times of the commencement and termination of the eclipse by means of the time of new moon.
english translation
avanatyA arke grAso digjJeyA valanayAavanatyA ca । tithyavasAnAdvelA karaNe kathitAni tAni mayA ॥ 5-18 ॥
hk transliteration by Sanscript