ft J \

/va

t A> t

U a

i \

PC12M

ll I ll I llll.l.il.

Illl ll II ll I I I

"111 il 111 li i 111 ii I. 1 1 li i ill i i Im li 11 li i i li nl i 11

■ 111 ■ ■ i

11 11111

ll-Ll I 11

J-llLi i i l,i i.

CHART 49

Curves Showing P, P', P', and i. Quarterly Data, United States , 1890-1927.