The Astronomical Observatories of Jai Singh c15.s1.t6.19

c15.s1.t6.19

Such is the orthodox Hindu text relating to instruments. Nothing of material value appears to have been added to these instructions until the methods of the Yavanas were introduced, by Mahendra Sūri and others; but Bhāskara (Siddhānta Siromani XI, 16) claims to have invented an instrument called Phalaka Yantra,² which, he says, is an "excellent instrument, calculated to remove always the darkness of ignorance and is the delight of clever astronomers." This instrument is simply a board divided by horizontals into 90 equal parts. At the centre of the 30th graduation from the top a pin, or style, is placed perpendicular to the board, and round it a circle is drawn of radius=30 divisions, which is graduated in ghaṭis and degrees, and attached to the pin is an index arm (paṭṭika). The instrument is suspended by a chain, and is used for observational purposes. It is in fact part of a very simple astrolabe. Bhāskara did not seem very pleased with his instrument, for, he concludes (XI, 40) by saying "But what does a man of genius want with instruments, about which numerous works have treated? Let him only take a staff in his hand, and look at any object along it, casting his eye from its end to the top. There is nothing of which he will not then tell: its altitude, dimensions, etc." This sums up, very well indeed, the attitude of Hindu astronomers.