सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

418 estimate 1581/2 × 1/51566 × 3438 = 53′ approximately. Its modern value is about 57′ so that the Hindu estimate is not far from truth. Here 1581 and 51566 are the values of a and d in Yojanas according to Bhāskara. The Hindu astronomers do not, however, proceed exactly as we have done in the para above to obtain the maximum horizontal parallax. Their treatment is a little different and is as follows. Whereas according to Modern astronomy E M̂′ A (fig. 93) is viewed as the horizontal [चित्र: Fig. 93] Fig. 93 parallax, in Hindu Astronomy MÊM′ or the angular measure of the Moon’s path equal to the radius of the Earth is taken to be the horizontal parallax. Both, of course, mean the same as is seen from the figure. In as much as the Hindu astronomers knew very well what they term कलीकरण or converting linear distances into angular measure, converting a linear magnitude equal to the radius of the Earth namely MM′ at the lunar orbit into angular measure, they got MM′/EM × 3438 = 1581/2 × 1/51566 radians = 52′-42″ as the maximum horizontal parallax.