Astronomy and High-speed Inertia. 91 



excentricity (though only on the assumption that the aspect 

 of its orbit to the sun's way does not differ numerically from 

 that of Mercury). Its value for ?i revolutions of the planet is 



•0002277ni - (10) 



ec 



For Mars e is variable but is about 9*33 per cent., 

 i'=10" 4 c/l*22 J , and the period of its revolution is 687 days. 

 So in a century of earth years its perihelion would progress 



2-27 x 365 xlO-V _ . , 



-con /^TVoo — lUoa = ■ seconds of arc. 



6'S< x -0933 x 1*22 



I do not know what the actual outstanding discrepancy is 

 in the case of Mars : the longitude of its perihelion differs 

 from that of Mercury by about 100°. 



As stated above, in order to rotate the orbit forward, 

 i. e. to secure apsidal progress, the main solar motion which 

 is to be compounded with that of the planet must have a 

 component agreeing with the motion of the planet at 

 aphelion : a component agreeing at perihelion would cause 

 regress, and a component along the major axis would only 

 modify the excentricity. I now point out, for what it is 

 worth, that if the main solar-stellar- drift in plane of ecliptic 

 were of magnitude 3 (meaning 3 x 10 -4 d:) and were directed 

 towards longitude 294°, it would have a component 



2 in the direction of the aphelion motion of Mercury, 

 2 „ ,, „ „ Mars, 



4 5? " >j J? -hjarth, 



"""$ t> 5? ?» ?? venus; 



thus suggesting that through a comparison of the outstanding 

 discrepancies between theory and observation for different 

 planets, if they were definite enough, it might be possible to 

 get some indication of the direction as well as the magnitude 

 of the sun's true motion through the aether of space. 



Summary. 

 The arguments are : — 



1. That motion of matter through aether has a definite 

 meaning, apart from relative motion with respect to 

 other matter. 



2. That an extra inertia due to this motion is to be expected 

 at high speeds, in accordance with the FitzG-erald- 

 Lorentz contraction. 



