38 20 ab. For the other (fve planets) the centre (of the 71anda or slow'epicycle) moves on (the circumference of) the epicycle of the equation of conjunction, i.e., the ऽghra or 'fast' epicycle) with the mean velocity of the Sun 20 c-d. The centre of their $ghra epicycle is the centre of the (celestial) globe itself and (the plames of) these (epicycles) are not oblique to (that of), the ecliptic ; (i.e., they are in the same plame as the ecliptic). ! 21. In the case of Mercury and Venus, their own orbits are stated to be the same as their $1glhra epicycles, measuring.them with respect to their ऽghra epicycles (which are taken as 360 degrees each) In the case of these, the increase and decrease of the 7107d epicycles alone are according to the hypotenuse (extended from the centre of the 71071da epicycle to its circumference where the planet is) 2. In all cases, the circle on which the velocity of a planet is measured (from fundamentals) is termed the 'ecentric circle ' (prati 71a११dala). And, that circle on which the motion of the planet is to be (projected and) understood (i.e., measured) is termed the 'orbital circle 23 a-b. When they are one outside the other, (the outer) one is called the upper (ucc८) (circle) and (the inner) one lower (rca) (circle) 23 c-l. Here, the two circles of radi equal to the difference between the centres of the orbital and eccentric circles are drawn at the extremities of the joining the two centres ; these two will then be the 1ucc८ (upper) and rica (lower) circles . 24 a.b. The motions of the planet and taken here in opposite directions. higher apses are to be 1. The idea is that the 'fast' (ऽghra) epicycles are concentric with the ecliptic and lie in its plane and that the celestial latitude (wiksepa) of the planets is caused by the deflection of the 'slow' (7107da) epicycles which move on the circumference of the 'fast' (gra) ones. The maximum defetion of each planet is given in verses 8०-9a above.
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