258 Tests of HerschePs ^Ethereal Physics. 



pound of air." One cipher, however, has been omitted here, 

 and three ciphers were omitted in his reference to HerschePs 

 estimate of aetherial stress (I. c. p. 390). 



The following paragraph (/. c. p. 415) furnishes another 

 evidence : — 



" The ratio of the elasticity to the density in the aether is 

 exceedingly large compared with the same ratio in air. The 

 temperature of air being taken at 60° F. and the aether at 

 20° F., absolute, the ratio is, with sufficient accuracy, 



( 98 ^ o y ) 2 = 8x 10" nearly." 



HerschePs result, calculated upon the same basis (op. cit. 

 p. 282), was 811,801,000,000. Through an inadvertent 

 transposition, Maxwell {Enc. JBritan., English edition, article 

 "Ether") gave 842*8, instead of 482-8, for the quotient of 

 30'176 by j*g, thence deducing for the aetherial density 

 9*36 x 10~ 19 . Substituting in (1) the corrected value of 

 d 2 h- d\ (5*32 x 10~ 19 ), we get, for HerschePs estimate, 

 e 2 : e.\ : : 1 : 1,636,750. This represents an aetherial elasticity, 

 or "bursting-power," of about g-g^o ounce on each side of a 

 cubic inch, instead of " upwards of seventeen billions of 

 pounds." The weight of the cubic inch of aether would be 



011 y 2,4 6 7,5 0,0 0,»0 0,0 0.0 0.0 0UnCe * 



The doctrine of conservation of angular velocity lends im- 

 portance to the following additional test : — 

 v k = 186,000 miles = velocity of light ; 

 t K = 498*99 sec. = time in which light traverses Earth's 

 semi-axis major, according to Nyren's constant of 

 aberration ; 

 p = v K x £ A = 92,81 2,000 miles = Sun's mean distance ; 

 n = 214-4513 ='p-*-r ; 

 r = 432,790 miles = Sun's semi-diameter ; 

 r 3 = 3962*8 miles = Earth's semi-diameter ; 

 \/g7p= 2^—31,558,149 = 18-479 miles = Earth's mean 

 orbital velocity ; 

 g a = -0000036791 mile = Sun's mean gravitating accele- 

 ration in Earth's orbit ; 

 <7 = n 2 g a = '1692 mile = gravitating acceleration at Sun's 



surface ; 

 g z z=. -006772 mile = gravitating acceleration at Earth's 



equator ; 

 t = 1,099,291 sec. =12*7233 deg. = v k -+-g Q = time of solar 



half rotation ; 

 m = Sun's mass ; m 3 = Earth's mass. 



m : m 3 : : g r 2 : g z r£ : : 332,077 : 1. 

 Haverford College, Pennsylvania. 



