[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) › c8.18 # The Astronomical Observatories of Jai Singh c8.18 The Astronomical Observatories of Jai Singh c8.18 - **Language:** English ### [c8.18](https://indike.org/pramana/ins.science.kaye-1918.c8.18) The \*Chakra Yantra\* (circle instrument) is an equatorial. There are two at Jaipur each 6 feet in diameter (figure 57) and one at Benares, 3 feet 7 inches in diameter. The \*Chakra Yantra\* is fixed so as to revolve about an axis parallel to the earth's axis. At the southern end of the axis of the instrument is a separate graduated circle, fixed on the supporting pillar. The axis carries a pointer, which indicates the hour angle on the fixed circle; and the main movable circle carries an index and sighter (figure 68). - [Previous: c8.17](https://indike.org/pramana/ins.science.kaye-1918.c8.17) - [Next: c8.19](https://indike.org/pramana/ins.science.kaye-1918.c8.19) - [Up: c8](https://indike.org/pramana/ins.science.kaye-1918.c8) --- Source: [https://indike.org/pramana/ins.science.kaye-1918.c8.18](https://indike.org/pramana/ins.science.kaye-1918.c8.18) · Pramāṇa