vss. 25-28] DISTANCE FROM THE PRIME MERIDIAN 9 divided by the radius (i.e., 3438') is known as the (Earth's) cir- cumference at the local place. 1 The Earth's circumference at the local place means "the circumference of the local circle of latitude", A rule for finding the distance of the local place from the prime meridian : 25-26. The circumference of the Earth multiplied by the differe*;e between the latitudes of (a place on) the prime meri- dian and the local place and divided by the number of degrees in a circle (i.e., by 360) gives the bahu (i.e., the base of the longitude triangle) due to the local place. The oblique distance from that local place to (the place on) the prime meridian is the hypotenuse (of the triangle). The square root of the difference between the squares of that (hypotenuse) and the bahu is said to be the longitude (in yojanas of that place). 2 The longitude in yojanas of a place means the distance of the place from the prime meridian in terms of yojanas measured along the local circle of latitude. In the Maha-Bhaskariya, the above bahu has been called the koti (i.e., the upright of the longitude triangle). For details, see my notes on MBh, ii.3-4. Criticism of the above rule : 27. Some learned scholars say like this; others say that it is not so, because of (i) the grossness of the hypotenuse and (ii) the sphericity of the Earth. 3 Srlpati (1039 A.D.), too, has criticised the above rule for the same reasons. Criticism of another rule : 28. (It has been said that) the difference between (the longitude of) the Sun derived from the midday shadow (of the g nomon at the local place) 4 and that calculated for the middle 1 Cf. MBh, ii. 10(iii).
- Gf. MBh, ii. 3-4.
• Gf. MBh, ii. 5. 4 See infra, iii. 29-33.