The absorption spectrum of lead vapour has been photographed at good dispersion in the quartz ultra-violet and Schumann regions and previous lists of lines and levels for Pb I considerably extended. Long series have been found converging on the ground levels of Pb II; these series contain marked examples of configuration mixing effects, including autoionization `resonances' of the type emphasized recently by Fano and Cooper. A small amendment to the accepted value for the ionization potential is suggested.