1919. ] Ancient Hindu Spherical Astronomy. 177 
Br Br au 
R. bu ap 4” 0, then ES tine 
and B is a ‘station’ of the planet and 2AZB is the angle of 
retrogression Instead of Bz the Surya Siddhanta gives ‘the 
difference between the hypotenuse and the radius,’ that is 
R — EB or EB’ - R. 
e text then gives the angles ABE for the stationary 
points B as follows :— 
Mars. Mercury. Jupiter. Venus. Saturn. 
36 50 7 6 
16 
from which the angles of retrogression AHB may easily be 
calculated if r/R be known. The Hindu texts do not give 
this value definitely, but it is approximately e, calculated for 
the epicycle of ‘conjunction.’ 
21. Latitude.—The node, Rahu. is said to cause the 
deviation of the planets in latitude (SS. ii, 6). The later rule 
for latitude given is 
_ B sin AA 
B ae r / yr’ 
where £’ is the maximum deviation as seen from the earth at 
its mean distance, 7 is the true distance of the planet from the 
earth, and 7’ is its mean distance, and 4A is the distance of the 
planet from its node. The deviations are given as follows :-— 
Mer- 
| Moon. | Mars. 
cury. 
Pafichasiddhaéntikaé f OT arr 1s bE a eles 2 oe 
ee 
Siirya Siddhanta.. | 4° 30’ | 1° 30’| 2° 0/| 1° 0’| 2° 07; 2 O 
Jupiter.| Venus. | Saturn. 
Parallax. 
the meridian. This latter statement is not true, as Whitney 
points out,* unless the ecliptic is also bisected by the meridian. 
(See § 6(9) ). 
* J.A.0.S.—1858, p. 286. 
