[Pramāṇa](https://indike.org/pramana/) › [Studies](https://indike.org/pramana/ins) › [Science, technology and education](https://indike.org/pramana/ins.science) › [The Astronomical Observatories of Jai Singh](https://indike.org/pramana/ins.science.kaye-1918) › c8.29 # The Astronomical Observatories of Jai Singh c8.29 The Astronomical Observatories of Jai Singh c8.29 - **Language:** English ### [c8.29](https://indike.org/pramana/ins.science.kaye-1918.c8.29) 25. The Dhruva Bhrama Yantra or ‘Circumpolar instrument’ is another modern Hindu instrument of rather crude workmanship. It consists of a square plate, with a slit near to and parallel to one edge, and a freely revolving weighted index with four pointers. If the plate is held vertically in such a position that the Pole star and the star \*Markati\* (Kochab or \*β\* Ursae Minoris) are in line with the slit, then the pointer marked \*Ghaṭī\* will indicate sideral time in \*ghaṭīs\*.² The other pointers indicate the rising sign, the sign on the meridian, and the rising, and setting \*nakshatras\*.³ The back of the instrument is marked \*Turīya Yantra\* (quadrant instrument), and consists of a hinged rod, two sighting rings on the edge parallel to the slit, and a graduated quadrant consisting of eleven scales. When the sun shines through the sighting ring the index shows the altitude and the time. Also a list of the 28 \*nakshatras\* (initials only), starting with Aśvinī and proceeding in the usual order,³ is given, and to each asterism is attached a number varying from 12½ to 18½. - [Previous: c8.28](https://indike.org/pramana/ins.science.kaye-1918.c8.28) - [Next: c8.30](https://indike.org/pramana/ins.science.kaye-1918.c8.30) - [Up: c8](https://indike.org/pramana/ins.science.kaye-1918.c8) --- Source: [https://indike.org/pramana/ins.science.kaye-1918.c8.29](https://indike.org/pramana/ins.science.kaye-1918.c8.29) · Pramāṇa