PROJECTION OF ECLIPSES the centre of the circle. The Moon's latitude for the middle of the eclipse should then be laid off from the centre along that line. 175 Construction of the phase of the eclipse for the time of the middle of the eclipse : 59-60. Quickly cut off the eclipsed body by means of a pair of compasses (one leg of) which is placed at the madhya- bindu and (the other leg of) which is streched out by half the specified true measure of the eclipsing body. The portion thus cut off (in case the eclipse is partial), or the entire disc of the eclipsed body drawn (likhitam) on the projection (in case the eclipse is total)-all of that is clearly seen (in the sky) in that way at the time of the middle of the eclipse. By the world likhita, says Parameśvara, is meant a total eclipse, or, in case the Moon's latitude is zero and the disc of the eclipsed body is larger, an annular eclipse. Construction of the path of the eclipsing body: 61. Draw (an arc of) a circle passing through the three points set down above with the help of two fish-figures: this is the path of the eclipsing body. The phase of the eclipse for the given time is ascertained (by determining the position of the eclipsing body on that path and drawing its disc with its centre) there.¹ A method for calculating the phase of the eclipse for the given time : 1 62-63. Multiply the difference between the (true) daily motions of the Sun and the Moon by the sthityardha-ghatis* minus the given time (isṭakala) and divide the product by sixty. Add the square of the quotient to the square of the Moon's nati (corrected latitude) (for the given time) and then take the square root of that (sum). This (square root) is (the length of) 1 This rule occurs also in ŠiDVṛ, 1, iv. 34. I, That is, ghafis corresponding to the sthityardha,
