Francis Bitter invented the bitter plate
used in resistive magnets (also called bitter electromagnets. ) He is the one who thought of using dust to visualize a magnetic field (remember in grade school when you put metal filings on a paper with a magnet underneath?) He built the bitter electromagnet by using stacked copper plates, rather than coiled wire. Previous to this time there was no way to cool the magnets so their power was limited.
Dr. Bitter was born in Wehawken, New Jersey. He studied at Columbia University graduating in 1924. He continued his studies in Berlin from 1925-26 in physics and received a PhD at Columbia in 1929. He is a 3rd generation PhD from Hermann von Helmholtz who had 9 Nobel Prize winners in his academic progeny. Robert C. Richardson, one of Francis' students recieved the Nobel prize in physics in 1996.
His main contribution focuses on the magnetic properties of matter. He studied gases at Caltech with Robert Andrews Millikan, worked on various theoretical and applied problems at Westinghouse Electric and Manufacturing Company in Pittsburgh. In 1934 he joined the faculty at the MIT where he developed the bitter electromagnet which was/is the most powerful electromagnets design. The MIT National Magnet Laboratory in Boston is named in his honor. He also did work in the first characterization of the zeeman effect.