4872.] 407 [Chase. 
9. The velocity of planetary revolution at the Sun’s surface : velocity 
of solar rotation, nearly :: Earth’s orbital radius : Sun’s radius. 
955, 870-4, 421.7—216.178 ; 216.1738+214.86—1.00613. 
10. The square of Jupiter’s orbital radius : square of Earth’s orbital 
radius, nearly :: g at Sun : g at Earth. 
27.2925. 20282—1.00824 (Compare No. 1). 
AATHEREAL DENSITY AND POLARITY. 
By Piiny EARLE CHASE. 
(Read before the American Philosophical Society, May 16th, 1872.) 
If the conditions of equilibrium in a perfectly elastic gas have been 
‘disturbed by explosion, in the restoration of equilibrium, the particles 
will simultaneously rush towards each other, and towards the attractive 
centre m. If h is the extreme excursion consequent on the explosion, 
2h 
the centre of oscillation of each exploding particle being at ——, the centre 
oO 
of gyration of its return towards the centre of gaseous mass ( ) is at 
a 
Siie) : : j ae dh : 
ac The centre of gyration of the fall from Ton to the Earth, is at 
4 4 
5h : : : Oh Oo - 
above the Earth’s surface, or at 7--——— from the Earth’s centre. 
a7 a7 
e s 
‘ dh : ees : dh aes 
If i :7+—— :: the orbital vis viva about a diameter 90° the vis viva 
‘ . 
: : 5h 
which would be communicated by virtual fall through Sees i: 4s we 
have 27r—108/ ; = d!--577.113 miles ; {91,345,800 miles ; — 
68666 
78666 
estimated velocity of hydrogen (6050, Clausius; 6055, Joule) to, this 
theoretical velocity, seems to indicate that the elasticity of hydrogen is 
nearly perfect. The inference is strengthened by the close approxima- 
tion of my first estimates by flame analysis, to the mean of the best 
astronomical estimates of the Sun’s distance. 
Let d/—density of luminiferous ether; d//—density of hydrogen. 
Calling the velocity of sound in hydrogen 4163 feet, and the velocity of 
light 183,454 miles, if the elasticities are the same we have the proportion, 
ad! : da!’ +: 4168? : (188,454<5280)? 2:1 : 54, 180,000,000. 
Upon the hypothesis that gravitation is an incidental result of sethereal 
6.8666 ; y 2gd’ —6103 feet per second. The approximation of the 
