292 HINDOO ASTRONOMY. 



seven maha yugs are elapsed, and we are now in the sati/a 

 yug of the twenty-eighth, which consists of 1,728,000 saura 

 years. Hence the years, since the beginning of the calpa, 

 may be found ; but from this 100 times 474 divine years 

 must be deducted, or of that product multipUed by 360 

 for human years, that being the term of Brama's employ- 

 ment in the creation, after which the planetary motions 

 commenced. 



By following out the calculations, the calpa is found to 

 contain 4,320,000,000 years ; and the period of it elapsed at 

 the end of the last satya age, v^'hen the Surya Siddhanta 

 is supposed to have been written 1,970,613,360 years. 



The bhagana, or zodiac, is divided into twelve 7-asis, the 

 rasi into thirty bhagas, the bhaga into sixty calas, and the 

 cala into sixty vicalas. The rasi, therefore, answers to a 

 sign or 30°, the bhaga to a degree, the cala to a minute of 

 a degree, and the vicala to a second. 



We have already given the Hindoo names of the planets, 

 and therefore need not repeat them. In one yug the sun, 

 Mercury, and Venus complete 432,000 madhyama revolu- 

 tions through the zodiac ; Mars, Jupiter, and Saturn make 

 the same number of sighra revolutions : these answer to 

 what we now call their revolutions about the sun. The 

 moon makes 57,753,336 madhyama revolutions, Mars 

 2,296,832 madhyama revolutions. Mercury's sighras are 

 17,937,060, Jupiter's madhyamas 364,220, Venus's sighras 

 7,022,376, Saturn's madhyamas are 146,568. The moon's 

 apogee makes 488,203, and her ascending node 232,238 

 revolutions. 



The time between sunrise and sunrise is the bhumi savan 

 day, of which the yug contains 1,577,917,828. The num- 

 ber of nacshatra days is 1,532,237,828, of chandra (lunar) 

 days 1,603,000,080, of adhi months 1,593,336, of tit'Ms 

 25,082,252, of saura months 51,840,000. 

 From these numbers it has been found that 



The mean time of a lunation 29d. 121t. 44m.- 2.79s. 



Time of moon's sidereal revolution 27 7 39 12.64 



Hindoo year 365 6 12 36.5f) 



Diurnal revolution of stars 366 6 12 36M 



It appears from a commentary on the Surya Siddhanta, 

 that the Hindoos knew that the moon revolves once on her 

 axis in a lunar month, and consequently has the same side 



