Chase.] 4:0U [June 17, 



This equation furnished the data for computing a less arbitrary series of 

 natural units, L^, T^,, M^. The British Nautical Almanac gives an estimate 

 of Sun's apparent semi-diameter, (?■„), which makes Earth's semi-axis 

 major equivalent to 214.45 r„. Hence we find (see foregoing note): 

 Vo = Vi = B;^ = .4307721 ?•„ = 3 VIII metres. 

 v^ = .0006252556 r„ — 435443 metres. 

 G„ = .0000003909446 r, = 272.26 metres. 



L„ = (-f^ r„ — 474657.14 r„ = 33 XIII metres = solar modulus of light. 



T„ = p-" = 1101875 sec. 



M„ oc gr"^ = 331700 © = 2 XXXIII grammes. 



Among the apparent advantages of these units over those of Dr. Stoney, 

 are the following : 



1. Lg is the height of a homogeneous sethereal solar envelope, which 

 would propagate waves with the velocity of light. 



2. Tg is the time in which the sum of the solar centripetal accelerations 

 of maximum gravitation is equivalent to the sum of the solar reactions 

 against the centre of gravity of all other cosmical bodies, in the alternate 

 projection from and return towards the disturbing centre of gravity. 



3. M(, is the controlling mass of the system, and, consequently, of all 

 the physical phenomena which occur in any part of it. 



4. L„, Tq, Mq can be estimated more easily and more accurately than 

 Li, Ti, Ml. 



5. G-g is the greatest possible gravitating acceleration within our sys- 

 tem. 



6. Vo is the greatest known velocity of wave-propagation. It is true 

 that Wheatstone's unconfirmed experiments, as well as my own ratio of 

 ms mva of excursion to vis viva of propagation (9 : 5), indicate greater 

 possible velocities. But Wheatstone did not eliminate the influence of in- 

 duction, and Maxwell's application of my ratio was confined to the excur- 

 sion of particles through very narrow limits. 



7. All of those maxima are eminently natural maxima, and, therefore, 

 suitable for natural standards. 



The following equations show the mutual relations of the two sets of 

 units : 



Li = 33 L. 

 Ti = 33 L. 



M„-hMi= 2 XL. 



48. Rotating Vis Viva. 



The photodynamic ratio of the velocity of light to the equatorial velocity 

 of stellar rotation is expressed, as I have shown (Note 34), by the propor- 

 tion 



Stellar modulus of light : stellar semi-circumference : : v^ : v^. 



The centre of gravity of the universe must be stable, so far as any modi- 



