Abstract
By using the vacuum Mach-Zehnder interferometer facility and the hook method it has been possible to measure the relative f-values of the first six lines of the principal series of MgI, and of the intercombination transition 3s2 1So-3s3p 3P01 at 457.11 nm. These relative values have been placed on the same absolute scale by reference to an absolute value for the resonance line.