Chase. ] 520 [Sept. 20, 
and aphelion, and the mean distances of Venus, Mars and Jupiter, will 
be represented by succeeding abscissas of the same series, as in table IV. 
(IV.) 
C (6) E 
.047818 
187943 
.830020 
474049 
1 .6200380 .606859 +-.081 
6 - 767963 . 782950 —.085 
Ze .917848 .907889 +-.028 
4 6 1.069685 1.083980 —,088 
pe 1.223474 1.208919 +.034 
Z «6 1.879215 1.885010 —.014 
has! 1.536908 1.561101 ae UK 
fs 1.696553 1.686040 +-.025 
oe 1.858150 1.850507 +.018 
Su 2.021699 2.021443 +-.000 
f°) 2.187200 2.191493 = 1010 
2@* 2.354653 2.353070 -+.004. 
A 2.524058 2.513999 +028 
2.695415 
2.868724. 
y 3.043985 3.048392 1010 
y— wt 3.221138 3.211038 +..024 
In a communication which I presented to the Society, May 16th, 1872, 
I indicated some simple relations between the superficial gravity and the 
times of rotation of the Sun, Jupiter and the Earth. If those relations 
are, as I believe, determined by an influent force, we may reasonably look 
for some analogous relations between our own and other stellar systems. 
In the solar-foeal parabola which passes through ¢ Centauri and has 
its directrix in a linear centre of- oscillation of a solar diameter, twenty- 
seven successive abscissas may be taken in regular progression, 
[ey = 0), EO) om) 
between the star and the Sun’s surface, nine of which will be extra 
planetary, nine will be in simple planetary relations, and nine will be 
intra-planetary. 
The upper extra-planetary abscissa bears nearly the same ratio to the 
modulus of light, as I bears to solar radius. 
The limiting abscissas of the planetary series are determined by com- 
pining diametral centres of oscillation (2><3), with centres of explosive 
condensation ($), and of explosive oscillation (3). 
The planetary series, between these limits, is } 9, 2 @, 3%, 4 mean 
asteroid, § 2/, $ kh, $ 6. 
€ Mean centre of gravity of % and @ at heliocentric conjunction, 
+ Mean centre of gravity of all the planets, at heliocentric conjunction. 
