94 DIRECTION, PLACE AND TIME (midday) shadow (of the gnomon). The details are being stated below. We have proved above (stanza 54) that sankvagra Rsin a Therefore - Rsin Rcos Also, from stanza 5 above, we have Rsin Rcos . equinoctial midday shadow 12 sankvagra x 12 Rsin a equinoctial midday shadow=: Method of finding the Sun's agra by observation and deriving therefrom the sankvagra and then the equinoctial midday shadow of the gnomon and the latitude or colatitude of the place: 56-60(i). One should erect a (circular) platform, as high as one's neck, with its floor in the same level, and its circumference graduated with the divisions of signs, degrees, etc., and bearing the marks of the directions. (Then standing) on the western side thereof, one, having undisturbed state of mind, should, with the line of sight passing through the centre of the circular base, make the observation of the Sun when (at sunrise) it appears clinging to the circunference, (and mark there a point). The (arcual) distance, measured along the circumference graduated with the marks of degrees, between the end of the line drawn eastwards (i.e., the east point) and the point where the Sun is observed is the arc of the Sun's agrā. The Rsine of that (arc) is (the Rsine of) the Sun's agra. The minutes of the difference between that (Rsine of the Sun's agra) and the Rsine of the Sun' meridian zenith distance are the minutes of the sankvagra, provided that the Sun is in the southern hemisphere; when the Sun is in the northern hemi- phere (and the shadow of the gnomon falls towards the north), the process is otherwise (i.e., the addition of the two). When, however, (the Sun being in the northern hemisphere) the
