ON THE ANALYSIS OF LIBRARY GROWTH
85
1900 1910 1920 1930 1940 1950 I960 1780 ∣820 I860 1900 1940 ∣980
FIGURE 1«. U, S. Grow Nalional Product in current dollars FIGURE 19. Invenlions. U. S. Palcnts issued 1790 1966.
with :t 5.89 year coπecιion for the Depression.