Oscillator strengths for Sc, Ti, V, Cr, Mn, Fe, Co and Ni which had been assembled at the University of London Observatory and adjusted to an absolute scale based on the f -sum rule are compared with independent measurements for the same atoms which had been made at the National Bureau of Standards and adjusted to an absolute scale based on experimental values. The systematic logarithmic difference is U.L.O.–N.B.S.= –0.19 ± 0.04dex. Possible errors are discussed and it is concluded that either method may be used for obtaining extensive absolute f -values with an accuracy of about ± 0.2 dex.