ELASTIC FORCES OF AQUEOUS VAPOUR, 599 
by means of the elastic forces which correspond to the tempera- 
tures 0°, 25°, 50°, 75°, and 100°; letting A, B, C, D, E be their 
logarithms. Taking besides 
(a)*=a, a =/ a, 
whence Pipe 
(8,)°=6; Bi=/8. 
We have then the five conditional equations,— 
Pee ee Oy Ra i PO a 
ia OO ee ly es 2 
C2 e “PCO, ss) ele 8 
DS a-ak -p eps fo Dodge Joos 
BO Oe ee Be OF SL 
From the gone (1.), (2.), (3.), we obtain-— 
_ [Az8—-(@+) B+C] (a—8) 
{4—1) (8-1) (#—-f)” 
_ [AB—(1+8) B+C] (6-1) 
(#—1) (B—1) (a—B) ” 
edit a Aa+(1+a«) B—C] (4—1) 
(«—1) (8—1) («—8) . 
If the values are substituted in the equations (4.) and (5.), we 
obtain two equations containing only « and £, 
Taking the equation (2.) on the equation (4.), we obtain 
D—B=ba(e—1) +08 (61); 
substituting for } and c their values, and reducing, 
D—B=Aap—B (a+1) (6+1)+C(a+B8+1), . (6.) 
D—C=(A—B)a¢8—(B—C) (2+)... . (7.) 
Taking the equation (3) from the equation (5), we have 
© B—C=6 a? (a®—1)4 ef? (821); 
substituting for 4 and ¢ their values, and reducing, 
(a+6) [Ae B—B(«+1)(8+1)4+C(«+6+4+1)] +AaB—CasB=E—C; 
or, in accordance with equation (6.), 
“(a+f) (D—B)+(A—C)e«B=E-—C. . ... (8.) 
From the equation (6) and (8), are obtained 
(D—C)(A—C) —(E—C)(A—B) 
«+= 5— ©) (G—B)—(A—B) (A—C)’ 
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