Oh yes you are right! That's apparently part of the first 1MeV TEM. Should be the high voltage source for the electron gun. The electron optics were most likel

Oh yes you are right! That's apparently part of the first 1MeV TEM. Should be the high voltage source for the electron gun. The electron optics were most likely magnetic, not electrostatic. There is a whole movie about it: https://images.cnrs.fr/en/video/1257 https://images.cnrs.fr/en/video/1257 Later MeV TEMs looked very different, and are now replaced by aberration corrected tools...