1872.1 405 [Chase. 
15. The theoretical mean excursion from Mars to the Sun, is near the 
orbital centre of oscillation for the Earth. 
(18) 1.5237—=.6772 5 .6772--.6667—1.01575. 
16. The theoretical mean excursion from the Sun to the Earth is nearly 
midway between the orbits of Mercury and Venus. 
(.8871-+.7233)= 5552 5 3+-.5552—=1.0006. 
17. The theoretical mean excursion from Mars to the Sun, is near the 
centre of gravity of Venus and Mereury. 
Gb» .38'71-+ 25 .'7283)-— (82+ 25)—. 6838 ; .68388---.6772 (See No. 15) =1.01. 
The theoretical mean excursion from the Earth to the Sun, 
- near the extreme excursion or aphelion of Mercury. 
.4666-—-(1—3)==1.05. 
. The theoretical mean excursion from Venus to the Sun is nea 
seg s perihelion. 
(1—8) X. 72833 —.32148 ; .82148+.3075 1.04542. 
20. The theoretical mean excursion from Pe, to the Sun is near 
the limit of the Sun’s possible atmosphere (the limit at which the 
equatorial centrifugal force is equal to gravity) 
[(1—3)X.3871] 365.2564 26.065 ;* 26.065 -+25.187—1.085. 
21. If the several planets were aggregated precisely, as they are ap- 
proximately, at aikbet or reverse centres of oscillation, the centre of in- 
ertia of the entire planetary system ()/ mr? im) would be near the 
orbit of Saturn. 
(8412 -+-25><2?+4.31.85 «32-32 42 +9307 18? +-2847.427? + 416.7 
542+-5382.5><812)+-(34 +25 + 31.85 +384 -+9307-+-2847.4-| 416.7+4.532.5) 
27.282 ; 27.28--27—1.0104. 
22. Notwithstanding the variations from centres of oscillation, con- 
sequent upon mutual planetary interactions, the centre of planetary 
inertia is still near the orbit of Saturn. 
Smr? (1,150, 671, 134) 3m (13167.12)—9.848? ; 9.5389 9.348 —1.0204. 
23. The distance of the Moon’s orbital centre of oscillation from: the. 
centre of the Earth, is very nearly a mean proportional between the limit 
of the Earth’s possible atmosphere and the Moon’s orbital radius. 
(4)? of 288,800 =26,538 ; (24-1. 40937) 3962.818 —26, 230 ; 
26,533 +-26, 230=1.01155. 
24. The vis viva of revolution at the Earth’s surface : the equatorial 
vis viva of rotation, nearly :: Earth’s orbital radius : twice Moon’s radius 
of orbital gyration. 
38, 800 
98 
4 
(17,066--1040.3)2-+ (91,328, 000 — ———_——_ ) —_ 1.00545 
2 
oO 
* The approximate coincidence of this period with Hornstein’s magnetic cycle (2614 days. 
Vienna Academy, June 15, 1871) is noteworthy, 
