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

198 constitute a different kind of symmetry as 1670—168, 1793—134, 1937—55, 1937＋55, 1793＋134, 1670＋168. We have now to comment upon the statement “तुलादितोऽमी च विलोमसंस्थाः ” which means that the rising times from Tulā to Mīna are in the reverse order i.e. the rising time of Tulā equals that of Kanyā; that of Vris- chika equals that of Simha and so on the rising time of Mīna equalling that of Meṣa. Thus the rising times of Tulā to Mīna being in the reverse order are 1670＋168, 1793＋134, 1937＋55, 1937—55, 1793—134, 1670—168 for the aforesaid locality. Why it should be so can be easily seen from the fact that Kanyā and Tulā are sym- metric with respect to the line ♈ ♎ which bisects the ecliptic (Ref. fig. 27). Or again we can see this in another Fig. 27 way; the chara-segments are successively (tan ϕ tan δ₁ — tan ϕ tan 0), (tan ϕ tan δ₂—tan ϕ tan δ₁), (tan ϕ tan ω— tan ϕ tan δ₂), (tan ϕ tan δ₂—tan ϕ tan ω), tan ϕ tan δ₁— tan ϕ tan δ₂ (tan ϕ tan 0—tan ϕ tan δ₁), (tan ϕ tan δ₁— tan ϕ tan 0), (tan ϕ tan δ₂—tan ϕ tan δ₁), (tan ϕ tan ω— tan ϕ tan δ₂), (tan ϕ tan δ₂—tan ϕ tan ω) (tan ϕ tan δ₁— tan ϕ tan δ₂), (tan ϕ tan 0—tan ϕ tan δ₁) where δ₁ = declination of 30°, and δ₂ that of 60°. These are there as found before 56, 134, 168, —168, —134, —56 upto Kanyā. But the remaining, though apparently are 56, 134, 168, —168, —134, —56 must be taken with a reverse sign because the rising point of the ecliptic will be to the south of the east point and δ will be negative from 180° to 360° longi- tude. Hence the chara Segments are 56, 134, 168, —168, —134, —56, —56, —134, --168, 168, 134, 56 so that from Tulā onwards they are in the reverse order as Bhāskara