During 1911 and 1912 E.H. Armstrong was studying for the degree of Electrical Engineer at Columbia University; he was not an especially brilliant student, in fact in many of his courses he did rather poorly. The writer knows because Armstrone was on of his students. The characteristics of alternating current machinery in general, did not prove very enticing to the young student, not because he was lazy or indifferent but because he had a hobby - and a vision. He was experimenting at his home with wireless apparatus and trying to find out how the three electrode audion of De...