Jyotiṣa-śāstra Saṅgraha: Threefold Division, Gaṇita Methods, Muhūrta, and Planetary Reckoning
विंशकुदीपौच्चगुणाच्छाया शंकूद्धृता भवेत् । दीपशंक्वंतरं चाथ च्छायाग्रविवरघ्नभा ॥ ५८ ॥
viṃśakudīpauccaguṇācchāyā śaṃkūddhṛtā bhavet | dīpaśaṃkvaṃtaraṃ cātha cchāyāgravivaraghnabhā || 58 ||
The shadow, measured with the śaṅku (gnomon), should be taken as twenty times the height of the lamp. Then, the interval between the lamp and the śaṅku is to be determined by the (computed) light that removes the gap up to the tip of the shadow.
Narada (in instructional mode within a technical/observational passage)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: adbhuta
It highlights that dharma is supported by pramāṇa (reliable measurement): correct observation and calculation are treated as aids to right practice and disciplined living.
Indirectly: by emphasizing precision and order, it supports well-performed religious observances; in Purāṇic practice, careful method strengthens sincerity and steadiness in worship.
Vedāṅga Jyotiṣa-style applied measurement using a śaṅku (gnomon) and shadow-length relationships—useful for observational calculations connected with timing and spatial determination.