NTRODUCTION xxxiii 4. Traditional verses suryadevas commentary preserves certain anonymous traditional verses on astronomical matters. Among these may be mentioned the revolution numbers of the apogees and ascending nodes of the planets over long periods (on Gitika, 9, pp. 26-27) and the bija correction for the mean longitudes of the planets with epoch at Kali 3600 (on Kāla, 11, p. 94). 5. Use of the Katapayadi notation It is noteworthy that for expressing numbers, besides the bhutasahkhyā notation, Suryadeva makes use also of the Katapayadi notation, (See, e.g., com. on ii. 11 12: pp. 48-51), which is a peculiarity of South India, corroborating his South Indian provenance. It might be added here that the Katapayadi notation is used by Suryadeva profusely in his commentary on the Laghumanasa. 6. Automatic Gola-yantra Suryadeva describes a Gola-yant a which rotates automatically keeping pace with time. About its construction he says : "Fix two posts on the ground in the north-south direction and fix on them the two ends of an iron rod (which passes through the centre of an armillary sphere). Apply oil to the holes at the north and scuth poles of the sphere (through which the iron rod passes) so that the sphere might rotate smoothly. Then, on the ground below the west point of the sphere dig a pit and fix in it a (narrow) cylinder with a (closed) hole at its lower end and as high as the circumference of the sphere. Fill the cylinder with water. Then fix a nail at the west point of the sphere and fasten to it one end of a string. Pass the string downwards along the equator towards the east point. Then stretch it upwards and take it to the west point (again). Then attach to the string a dry hollow gourd filled with mercury and place it on the surface of the water in the cylinder kept filled with water. Now, open the hole at the bottom of the cylinder. As the water flows out, its level falls. Consequently, the gourd, weighed down as it is by mercury, (also goes down) not leaving (the surface of) the water, and (the string attached to it) pulls the sphere westwards. The outflow of water should be regulated in such a manner that "30 ghatikas (= 12 hours), half the water in the cylinder flows out and A.Bh.S. v.
