The Astronomical Observatories of Jai Singh c9.s1.20

c9.s1.20

Cross wires are stretched from the cardinal points on the outer wall, and both walls are graduated. The inner wall is a convenient height for a man to walk on and to look over the outer wall. By the aid of a movable string and an assistant, azimuth (horizontal angles) observations can be made with fair accuracy. The instrument may be described as a fixed large circular protractor.