The Astronomical Observatories of Jai Singh c12.6

c12.6

The Dakshiṇovṛitti Yantra (‘Meridian instrument’) is shown in plate XXIV and in figure 62. The masonry work is fairly intact, but the graduations have disappeared. The instrument was originally something like that at Jaipur (figure 56). It consists of a wall lying in the meridian, and on its east face was a double quadrant, the centres of which were at points near the top corners of the wall and 25 feet apart. A portion of one quadrant is still visible, engraved in the lime plaster with which the wall is faced, but this is probably not the original graduation. On the ledge below the quadrants there are traces of a scale of tangents. On the west side is a flight of steps (figure 62) leading to a narrow platform at the top. At the south-west end of this platform is a small pillar, 2 feet in diameter: according to Hunter this was "graduated for observing the amplitude of the heavenly bodies at their rising and setting"; and was called Agra Yantra ('amplitude instrument'). The graduations have now disappeared. At the middle of the platform, and on the east side, is a small projection of the parapet, 2 feet 4½ inches long and deep. On this, Hunter tells us, was "constructed a horizontal dial called Puebha Yunter." There is no sign of this dial now.