The golden age of solar magnetography at Paris-Meudon observatory in the second half of the twentieth century

This paper describes advances in solar magnetography and developments in instrumental techniques of polarimetry and spectroscopy made at Paris-Meudon observatory in the second half of the twentieth century. The adventure started from Lyot expertise and extended progressively to the measurement of vector magnetic fields using various and improving polarimetric techniques (such as beam exchange or grid) or new spectroscopic methods (such as the MSDP imaging slicer), at Meudon and Pic du Midi, ending by the achievement of the state-of-the-art optimized and polarization free telescope THEMIS in 1999.