184 Lord Kelvin on the Motion of Ponderable Matter 



Here, r denotes the undisturbed distance from the centre 



of the atom, of a particle of the ether which is at distance 



r when at rest under the influence of the attractive and 



4w 

 repulsive forces. According to this notation -^-S(r 3 ) is the 



o 



disturbed volume of a spherical shell of ether whose un- 



4-7T 



disturbed radius is / and thickness hr' and volume -~-8(/ 3 ). 



Hence, i£ we denote the disturbed and undisturbed densities 

 of the ether by p and unity respectively, we have 



ph(r s ) = 8(r' 3 ) (10); 



whence, by (9), 



3[1 + K(1-/) 2 ] 2 

 3 + K(3-r')(l-?-') ' * * 



This gives 1 + K for the density of the ether at the centre 

 of the atom. In order that the disturbance may suffice for 

 refractivities such as those of air, or other gases, or water, or 

 glass, or other transparent liquids or isotropic solids, ac- 

 cording to the dynamical theory explained in §(16) below, 

 I find that K may for some cases be about equal to 100, 

 and for others must be considerably greater. I have there- 

 fore taken K = 100, and calculated and drawn the accom- 

 panying tables and diagram accordingly. 



P = 



(11). 



Table I, 



Col. 1. 



Col. 2. 



Col. 3. 



Col. 3'. 



Col. 4. 



Col. 5. 



r\ 



^- 3 = l + K(l-0 2 . 



r. 



r'—r. 



P- 



(p-iy. 



00 



1010 



o-ooo 



o-ooo 



101-0 



000 



•05 



91-25 



011 



039 



88-1 



•on 



•10 



82-0 



•023 



•077 



75-3 



•039 



•20 



65-0 



•049 



•151 



55-8 



•132 



•30 



50-0 



•082 



•218 



391 



•256 



'40 



370 



•120 



•280 



25-8 



•357 



•50 



26-0 



•169 



•331 



15*8 



•423 



•60 



17-0 



•233 



•367 



8-76 



•423 



•70 



100 



•325 



•375 



4-17 



•338 



•80 



5-0 



•468 



•332 



1-60 



•131 



•85 



325 



•578 



•272 



0-90 



-0033 



•90 



200 



•715 



•185 



0-50 



- -256 



•95 



1-25 



•865 



•085 



•35 



- -486 



•96 



116 



•897 



•063 



•36 



- -515 



•97 



109 



■928 



•042 



•39 



- -525 



•98 



1-04 



•957 



•023 



•46 



- "495 



■99 



101 



■982 



•008 



■61 



- 376 



100 



100 



1-000 



•000 



100 



- -000 



