of Eclipses, d¢ !specially of Lunar . Eclipses 14B 1 11,.717. The Hindu system now ussumes that this is the precise 8583 amount of the actual mean daily ion, in space, of all the planets, and ascertains the dimensions of their several orbits by multiplying it by the periodic time of revolution of each (see below 8)-290). The length of the sieve y being Bxd.25875348, the Sun's orbit as stated else whox (xit, 86), 4,881,500vojanas. From a quarant of this, by the ratio 3409: 3488, we derive the sn's distance from the earth, (680,480 y०jasas of 831.8 redii of the natih. 'This is vantly leA$ 1han his true distance, which is about 24,000 rad His horizontal rallux ix, of course, propor only over-xtirmatd. bein; mode to be nearly 4' (mmore exactly, 3 59.4) instead of 8.8, ॐ truealue, an annount८ so rall that it should properly have been neglected us inappreciable. It is an important prerty of the py!xof the Sun and rnoon Presulting from the anner in vjich the relative |fixtances of the luter frohn he cath are determinct, the•t they are no one anotlrer to the mean daily notions of the planets respectively: that is to sv
53 20 : 3' ; 780 85 52 8" ]Batch is lik I७ ३: 1931¥l! 1e fifteenth of 16• w}le nnePun daily motion, or equivalent to tle a। Imux Df He traversed by each plan , in 4 \a}js; the
- ference being, for the moon, about 38, for the sun, ubout B> We shall
Age ha, in the calculations of the next chapter, these differences Te negloete, and the paralax take a equilin the ) als, f© {he mean notion line 4 nfdfs. citeछruietence of the sun's orbit being 4,331,500 yjana, the S| 1nent = is yojana ny his diameter implies that mean apparent inmeter was nscat 2 24.8; for 880 : 32 2448 ; : 4.331,5) { O? is real tial ene; he rule valu of t.}he Sun's १parent diarieter 2 3.6. Ille 1esul८ riew |t by the Ghree stron2': *elative to the parallax, disturce Ind magnitutl of the sum nd so re no greatly dis cordant with those there presencd. Lipprchus tound the moon's horisontal paral!6x to be 57 Arietarchus had previously. ly observation on the angular distance of the sun aud moon when the latter is half-illuminated, Made their telative distances to be aw 19 to 1; this gave Hipparehu8 8 18 the Sun's per]tax. Polemy nunk®8 bho mean distances of the sun and moon from the earth equal to 121) and 53 radii of the earth, and their parallaxes 2 61" and 38 14" repectively: ho also states the diameter of the moon, earth, and sun to be a6 1, $है, 1B, while the Hindus make them AS R, und 13 है. and theiy true values, १s determined by modern poience are ($ 1, 8, and 412, nearly 19