Jyotiṣa-śāstra Saṅgraha: Threefold Division, Gaṇita Methods, Muhūrta, and Planetary Reckoning
तद्वर्गतो दशगुणात्पद भूपरिधिर्भवेत् । लंबज्याघ्नस्वजीवाप्तः स्फुटो भूपरिधिः स्वकः ॥ ८४ ॥
tadvargato daśaguṇātpada bhūparidhirbhavet | laṃbajyāghnasvajīvāptaḥ sphuṭo bhūparidhiḥ svakaḥ || 84 ||
From ten times the square of that value, one obtains a step-wise (approximate) circumference of the earth. But the accurate circumference is obtained by multiplying by the sine of the zenith distance (lamba-jyā) and then dividing by one’s own jīva (sine) value.
Narada (teaching in a technical/astronomical context within Moksha-Dharma discourse)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: adbhuta
It shows that Narada Purana integrates dharma with disciplined knowledge—precision (sphuṭa) and correct method are themselves part of righteous learning that supports clarity of understanding.
Indirectly: it frames sacred study as orderly and exact, encouraging a devotee to approach Vishnu’s cosmos with reverence and intellectual honesty rather than guesswork.
Vedāṅga Jyotiṣa/gaṇita: the verse references jyā/jīva (sine) operations and distinguishes approximate versus accurate computations for determining bhū-paridhi (earth’s circumference).