The Astronomical Observatories of Jai Singh c15.s1.t6.16

c15.s1.t6.16

(iv) Other Instruments—" So also," the text continues, "one should construct instruments (yantras) for the ascertainment of time. (20) When quite alone, one should apply quicksilver to the wonder causing instrument.¹ By the gnomon (sanku), staff (yashti) arc (dhanus), circle (chakra), instruments for taking the shadow of various kinds .......... (21), By water instruments, the hemisphere (kapāla), etc., by the peacock, man, monkey, and by stringed sand receptacles, one may determine time accurately. (22) Quicksilver-holes, water, and cords, ropes and oil and water, mercury, and sand are used in these: these applications, too, are difficult ..........