572 ON THE ANTIQUITY OF 



By De la Lande's tables, Hindu 



sphere (§ 12) - - 2^ 13o 58' 11,5 



DifTerence, the former less advanced by 54 11,5 



r'/ 



54'n",T X 100 



Hence, ^^ j^ '' " — - = 340 years, for the age of the 

 Surya Siddhanta from this operation. 



64. The mean motions of the Sun, Moon, Ju- 

 piter, and Saturn, are found by modern astronomers 

 to be subject to inequalities, on account of the mu- 

 tual attractions of the planets to each other ; there- 

 fore, before we proceed farther, it will be proper to 

 state here the formulae which have been given by 

 M. De la Grange, De la Place, &c. for com- 

 puting these inequalities. 



FOR THE SUN. 



Let n, = the number of years before A. D. i750, 

 then 7Z.2X. 000x8408"= the inequality according 

 to the quantities given in De la Lande's tables, 

 and is additive. 



FOR THE MOON. 



Let w, == the number of years before A. D. i700, 

 then 7Z.2 X. 00iii355" - n? ^.000000044" express 

 the inequality which is additive in this case. 



FOR JUPITER. 



Let 72, = the number of years before A. D. 1750; 

 J» = Jupiter's mean longitude ; ^S*, = Saturn's 

 mean longitude , then, + (20' 49",5 — n. 0",042733) 

 .6'm (5 S—.2 J. +5° 34' 8"— w. 58",88) express 

 the inequality. 



FOR SATURN. 



Let 7/, 7, -^S; be as in the last; then, — f48' 44' 

 — «.0,"lj.<S7;2{5.S'. — 27.-1-5= 34'8"— «. 58",88) 

 will express the inequality. 



I io^j. From 



