The Astronomical Observatories of Jai Singh c15.s1.t6.3

c15.s1.t6.3

The following is a summary of those parts of the early Hindu texts that deal with astronomical instruments. (i) The Clepsydra or Water clock is referred to in the *Jyotisha Vedānga*, where the amount of water that measures a *nāḍikā* (=24 minutes) is given. The more ancient form of water clock appears to have been simply a vessel with a small orifice at the bottom, through which the water flowed in a *nāḍikā*,⁶ but later on there came into use the form described in the *Sūrya Siddhānta* (XIII, 23): "A copper vessel, with a hole in the bottom, set in a vessel of pure water, sinks sixty times in a day and night, and is an accurate hemispherical instrument." The Pañcha siddhāntikā description ¹ (XIV, 32) is similar, but adds "Or else a nāḍikā may be measured by the time in which sixty slokas, each consisting of sixty long syllables, can be read out."