of Relativity, and Miclielson-Morley Experiment. 823 

 measurement of 6 does not rotate, are given by 





4tt 



~dt "Sr %r 



y, . . . . (i) 





with a similar set of equations obtained by writing (/, (/, li) 

 for (a, b, c) and — (47rC 2 ) -1 (a, 6, e) for 4tt(/, #, A), where C 

 is the velocity of light. 



Consider now a new set of axes rotating round z with 

 angular velocity ©. If accented coordinates are those re- 

 lative to these axes, we may write 



r'=r, z' = z, t / = t, O' = 0—(ot, 



B/^'=r}/?>', a/a* = d/as', :*fto=-dw, 



B/^ = ?)/?)*'-©d/r)6>'. 

 The solenoidal conditions are 



3 • . x "by ~dh "d / \ "do "dc n /rtN 



^W + 5f +r ^ = ^ ar > + S5 +r 5i= '- (2) 



where the variable coordinates may be accented. 



We derive three equations in the new variables,, the first 

 being 





4 ^/ = pK<^W)--^ 



If 



i', 6', c') = (a — 4:7rrcoh, b, c + ^itr&f) ^ 

 ,, , , , /. ©re , c»ra \ r ; * 



(3) 



then the three equations are similar to (1), the first being 



^^gy-'S? (4) 



The variables without accent may be eliminated after the 



usual manner. We find, if 



6 -i=l-©V/C 2 , (5) 



e -i(a,^c) = (a' + 4:7r©r'A / ,e- 1 &', d -kiem'f) \ fg * 



e-i (/; r A A) = (/ r/ -«rV/47rC«, e~y, # + an'<f/4ar&) J 



where e is a function of r. 



