Errata

Our article, “A Fertilizer Production Surface” ( This Journal, Aug. 1954), contains certain typographical errors that were not caught in proof reading. The following corrections should be made: In the first equation on page 469, the exponent should be F 1 . The order of the figures in columns 2 and 4 on page 479 should be reversed, with the smallest magnitude at the heading of these two columns. A negative sign should precede 5.682 in equation III on page 470. In equations 1 and 2 on page 473, the term should read 6.415P −.5 . The term in equation (1) on page 481 should read 5.359P −.5 . A minus sign should precede 5.7 in table 3.