FINDING THE DIRECTIONS. Certain writers, Bhāskara I tells us in the commentary, prescribed a gnomon of half a cubit (-12 angulas) in length and having twelve divisions. But, according to Bhāskara I, (although it was the usual custom) there was no such hard and fast rule. The gnomon could be of any length and any number of divisions. The gnomon should, however, be large enough, so that the rings of graduation on the gnomon may be clearly seen on the shadow. A broad and massive gnomon was preferred because it was unaffected by the wind. 57 As regards testing the level of the ground, Bhaskara I observes: "When there is no wind, place a jar (full) of water upon a tripod on the ground which has been made plane by means. of eye or thread, and bore a (fine) hole (at the bottom of the jar) so that the water may have continuous flow. Where the water falling on the ground spreads in a circle, there the ground is in perfect level; where the water accumulates after departing from the circle of water, there it is low; and where the water does not reach, there it is high."2 The same test has been prescribed by Govinda Svāmi³ and Nilakantha. After the ground was levelled, a prominently distinct circle was drawn on the ground as stated in the text. In the time of Sankaranārā- yaṇa (869 A. D.) it seems that all lines were drawn on the ground with sandal paste (candanakṣodārdra).5 The above circle having been thus drawn and coated with sandal paste, another small concentric circle was drawn with the radius of the gnomon. The gnomon was then placed vertically with the periphery of its base in coincidence with that circle. The gnomon was thus set up exactly in the middle of the bigger circle. The verticality of the gnomon was tested by means of four plumb-lines hung on the four sides of the gnomon. A rule for finding the directions: 2. With the two points where the shadow (of the gnomon) enters into and passes out of the circle, neatly draw a fish-figure (lit. fish). The thread-line which goes through the ¹ See Bhaskara I's comm. on A, ii. 14. 2 Bhaskara I's comm, on A, ii. 13. 3 In his comm. on MBh, iii. 1. 4 In his comm. on A, ii. 13. 56 Vide Sankaranārāyaṇa's comm. on LBh, iii. 1-2.
