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

88
Sun is at the point Q where Q is the point of intersection
of the celestial equator with the meridian of the place. If
the equinoctial shadow be denoted by ' s ' and the hypo-
tenuse of the triangle nGN namely nN be denoted by K
(called the Vishuvatkarṇa or the equinoctial hypotenuse)
then s / K = Sin ϕ and 12 / K = Cosϕ. If H Sin ϕ be the
Hindu sine of ϕ called the Akshajyā H Sin ϕ = R Sin ϕ
so that s / K = H Sin ϕ / R and 12 / K = HCosϕ / R = Lambajyā / Trijyā .
Substituting for H Cos ϕ / R the value 12 / K in equation I
above, we have
QST = Sphuṭa - paridhi = (Bhū - paridhi × 12) / K II
which proves the second statement given in the verse.
Regarding the third statement, which defines the Bhu-
Madhya-Rekhā (In modern text books of geography the
terrestrial equator is spoken of as the Bhu-Madhya-Rekha.
The terrestrial equator is called Niraksha-Rekha in Hindu
Astronomy which means the circle of Zero-latitude), it is
the primary meridian taken by Hindu Astronomers. In
modern astronomy the primary meriodian is taken as the
Greenwich meridian. Bhāskara has given four places locat-
ed on the Hindu primary meridian, but, Śrīpati gives many
more places located on this primary meridian under verse
96 Madhyamādhyāya namely (1) Laṅkā (2) Kanyākumārī
(3) Kāñchī (4) Pannāta (5) the six-faced white mountain
(6) Sri-Valma-gulmam (7) Māhishmatī (8) Ujjain (9) An
Āsrama (10) Pattasiva, a town (11) Sri Gargarāna (12)
Sthānviswara known also as purohita (13) Sītagiri and (14)
Sumeru. Some of these places cannot be properly identi-
fied but the following remarks may be made (a) Pannāta is
one of the fifty-six small countries into which India was
divided in ancient times according to the purāṇic literature