The isotope shifts in the 283. 3-nm resonance line of natural lead were measured by atomic-beam absorption spectroscopy with a 9. 1-m focal-length spectrometer. The spectrum was calibrated internally by the measured 6p7s **3P degree //1 hfs separation of **2**0**7Pb and by the value calculated from level-crossing results. The isotope shifts relative to **2**0**8Pb are minus 46. 6(6), **2**0**7Pb center of gravity; minus 74. 5(6), **2**0**6Pb; minus 142(3), **2**0**4Pb. The values are in units of 0. 001 cm** minus **1, the negative sign indicating a shift to lower wave numbers. The precision is nearly 1 order of magnitude greater than that of previous measurements.
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