t) 1 1

to 360° , is,

Wh,„ ,h, Mg le of ^Zi *' Earth m “‘

.W, s(m -M> = 360”, the S«»,he again in the same right line, an >

__ _360P__.(D-

* ~ m " M . nf a sy nodical revolu-

In which expression . denotes.^“foe mean daily nmUons,

Uon, « and M being den0 te any ^"^ponding

hut, as it is plain, m and M J ^ ^ be thesmall, of the mean motions, . ^ or hours,

time, however reckoned, whet er ^ Earth and the

Let P and p denote the sidereal penods

alanet; then, since P 1 '• M " 3 g 0)

• . substituting

\ *

.W-

3600 ^ ^ <«. » the >y00dic *'ad from either of these eX ^* C om puted.evolution of the planet may e thus, if * ** e

the synodic P en ’ „ n distance,We may differently e x P reSS , J the planet’s meanthe Earth ’s mean distance, and rWe have, by Kepler’s law

*. •. ’

p . p •• t :*■

and s =

365 A ,256384

365 a .256384

° r * ““ 1 - r ’ . r . or> the second

The first expression belonging * former express 1perior, planets *. and from these coin puted-4, H, the synodical periods may