452 
T= (We xf) TS EF” 
l 
In the case 7=|— 4, ) = 4 we so obtain 
dou 076i4 0°8 
“2 > - En ne 0 LT 
D Ge i Tear Ge 
and in the case 4—=j=—=4 
a 4 078 tates 07074 ae 
WD (ys $8") =— Bag + Ah BS  — —2x%08+-x(T,,—o)+%x= Lu (8) 
dt (D OO, 2 () 
4. We now proceed to the calculation of the quantities 77;. 
They have to satisfy the equations 
0 f oe 0d1; 
pe (4 gij F1) == 4 PD) VF gin gan lib fe . 
lj 0a; ljmn a; 
Expressing the equality of the terms of the lowest order on each 
side, we have 
Pa) Gg ea a (= 12:3) | 
Ot Ow, Ee 0x; : Hee 
ay OT \ ae 
ot (1) 0a) ; 
In order to be able to calculate the quantities 7’ we must make 
definite suppositions on the elastic properties of the bodies. Suppose 
them to be perfect liquids and suppose their expansions and com- 
pressions to be adiabatic. Then 
i ds den 
Th Op et 0 OEE) inn 
i U de, | ds 
(vid. Einstein “Formale Grundlage...” p. 1062). p represents the 
pressure and 
zé 
P=— { pdyp x 
« 
?o 
if gy represents the volume (in natural measure) at the pressure p 
and g, the volume at the pressure y,, both of a quantity whose 
mass is 1 at the pressure 0; ey —1. The tensor 77; becomes now 
Tij =—pgij + ip +e(l + Ph Zgim Gjl%mat: UV gad Va Pb: 
m ab 
Expanding the denominator and omitting all terms of higher than 
the first order, we find from this 
Tij 675.) +10 212; vts Aj Sie OG (10) 
ry en: N RE 1 | D) 
Pir 0 = ded KOR OE 
