Prekṣākrama: Instruments and Observatories
Explore India's observing tradition, from the gnomon, water clock and astrolabe to Sawai Jai Singh II's Jantar Mantars, the naked-eye mastery of Sāmanta Candraśekhara, and the modern observatories that carry the lineage forward.
Lessons in this chapter
- Yantra-Paramparā: The Tradition of Astronomical Instruments — Nine instruments of wood, water and copper, and the tenth that Bhāskara called the only true one
- Śaṅku and Ghaṭī: Shadow and Water — The gnomon read the real Sun, the sinking water-bowl counted the hours in any weather, and each kept the other honest
- Gola-Yantra: Armillary Spheres and Celestial Models — How a turning cage of rings let astronomers hold the sky in their hands, and make it keep time
- Yantrarāja: The Astrolabe Comes to Sanskrit — How a Jain monk at the Delhi court put the 'king of instruments' into Sanskrit verse in 1370, and how India's own ring instruments met it
- Jai Singh: The Astronomer-King and His Jantar Mantars — Five observatories in stone, built to correct the tables
- Sāmanta Candraśekhara: The Last Naked-Eye Master — The Odisha astronomer who corrected the siddhāntas with bamboo and wood
- Nava-Paramparā: From Madras Observatory to Chandrayaan — The lineage continues in modern Indian astronomy