P 
ih {| dq dp = | dq’ 8 p = dr «mr =| de. mr? 
e/’e « 0 
P 
ee (., 
‘ ry. Di 5 9 27 é 
dt(2T — mrq*) = — — 2ap = — — Zap 
‘ P Y 
0 
where r is the frequency, 7’ the total kinetic energy, ¢ the total 
energy of the system (27’=gs, the oscillations being harmonic). 
On the other hand, (6) gives: 
nh = | dg. p= 2p Pie, Gee Se 
substituting this on the right hand side in (d) we obtain: 
5 
OER ee 
D 
In this way the equations (33) and (34) of § 9 have been deduced. 
In order to compare this result with the formulae recently given 
by Pranck, we remark that each of these motions takes place in 
an ellipse, so that (with respect to its principal axes) it may be 
represented by the equations 
LEED °'s y= OBD ET ee ze | 
(a and > being the semi-axes of the ellipse, w = Zar) 
i may) ERD Id sE mod eta 
& 
NRE ODA el eee 
Yr 
Therefore according to (e) and (/): 
nh 
UD baie | ig. Megas oe Me tee ce (9) 
2awm 
nin')i 
oi cote Were 
arom 
Or: 
nh 
De a 
Twn 
Equation (9) is identical with the value given by PLANcK (see 
equation (65) of his paper). For (a—bd)’ however he gives values 
which are twice too high. 
Postcript at. the correction. Meanwhile Epstrm has published 
some highly interesting papers [Ann. d. Phys. 50 (1916) p. 489, 
p. $15). which show the importance of Sricke.’s method of the 
