358 
MR. fl. P. JOULE AND PROFESSOR THOMSON ON THE 
Now, by the empirical formula (17)? with equations (13) and (15), neglecting 
squares and products of the small quantities C, D, G, we find 
E: 
iooa-{d(~— Wg 
1 Vo ^o+iooy 
fo Fo + 100) s 
ioo{a (0+ b + (c+2 + |)5 
: A < 0 + B — 1O0(A( o +B){a( 0 +b( C +^+^) + D (7 0 _ V+Too) (<o+100? 
( 21 ) 
/P'V'-PVX 
V pv / 
/ „ D G\ /<£> <E> \ /_ D G \ /<f> <P \ 
( + +7s ^)(v”v) ”( C + ^ 75 + e;)(v~V 7 ) 
G \<fi‘ 
*" A ^+B + ( C + ii + |-) v 
a^ 4 . 75 +b 
A t n + B 
>(v + 
D . G\/P P' 
+75 + 75 ^ Vn 
n) 
and 
(A^j. 75 + B)“ \ 
S =jil- BI «5T-(«+T+“)(|-D) • • 
From the last, and the equation of condition (20), we find 
B=0 
(22) 
(23) 
(24) 
(25) 
(26) 
and 
^17(20= 
3D 
4G 
0 - 
JK t 0 +l7V'^' r ^ +l7 -r /o+l7 . 
Again, by equations (21) and (18) similarly used, we have 
A 
, = “00365343 . . . 
26. 
. . . . ( 27 ) 
and 
A * 0 + B‘ 
-1 
100 A 
100 ( A 4 + B) IA 4 + B 
c+ ^ + |) +D (^ _ (^) +G (?r(viW s )} = 
.... (28) 
“00001 1575. . (29) 
From (26) and (28), we have 
^ = •003653431 
*o (30) 
and t 0 = 273°“72 J 
That is, from the thermo-dynamic experimental result (20), and the experimental result 
(18) characteristic of the difference of temperature which we choose to call 100 from 
the freezing-point upwards, showing the effect on the pressure of air, we have determined 
the absolute thermo-dynamic temperature of the freezing-point. The result agrees 
within one-twentieth of a degree with that which we obtained in Section II. by the 
first plan, in which the same data as regards the increase of pressure of air from t 0 to 
4+100° were used, but taken into account on different and apparently less satisfac- 
