522 
MR. G. H. DARWIN ON THE 
With these values I find 
^ 2,594,000 
Cn— ; 0 = -0002594. 
The distances of the satellites referred to the mean distance of Jupiter from the 
sun are 
I. II. III. IV. 
lll"-74 177"‘80 283"-61 498 /,< 87 
Then taking Jupiter’s mean distance to be 5-20278, the logarithms of the distances 
in terms of the earth’s distance from the sun are 
I. II. III. IV. 
7-45002 — 10 7-65174 — 10 7-85453 — 10 S’09980 —10 
The periodic times are in m.s. days (Herschel's ‘ Astronomy,’ Appendix) 
I. 
1-76914 
II. 
3-55181 
III. 
7-15455 
IV. 
16-6888 
The masses given me by Professor Adams* from a revision of Damoiseatj’s work 
are in terms of Jupiter’s mass. 
I. 
II. 
III. 
i—i 
2-8311 
2-3236 
8-1245 
2-1488 
10 5 
10 5 
10 5 
10 5 
Combining these data 
according to the 
formula mfic 3 , w 
-here m is the mass of the 
satellite, I find for the 
chosen units— 
orbital momenta of the satellites 
expressed in terms of the 
I. 
II. 
III. 
IV. 
2406 
2489 
10993 
3857 
10 10 
10 10 
10 lu 
10 lu 
The sum of these is 19745/10 10 and is the total orbital momentum of the satellites. 
It is y^Q-th of the rotational momentum of the planet as found above. 
The whole angular momentum of the Jovian system is A 
10 10 
Saturn. 
There seems to be much doubt as to the diameter of the planet. 
The values of the mean radius at distance unity given by Bessel, De La Rue, and 
* He kindly gave me these data for another purpose.—See Ast. Soc. Month. Not., Dec., 1876, p. 81. 
