In developing his electric light bulb, Edison stumbled onto what physicists call "the Edison effect": the flow of electrons between cathode and anode of a vacuum tube. It is the great tragedy of Edison's life that he did not understand this effect, but merely patented it in the form of a toy.

An Englishman working for Edion, J. A. Fleming, realized its potential and paid a small fee for a license to work with it. Edison waved the money around, laughing at what he'd put over on this "college boy Englishman". Back in England, Fleming developed a diode (the "Fleming valve"), the first "radio" tube. Later, Lee De Forest extended the diode to a triode, which could control the flow, and "modern radio" began. Eventually, most of the essentials of Edison's inventions wer replaced by similar means.

Every one should also know that this "greatest" of American inventors did not male money on his patents. After his death, his partner in the Edison Company, acting as executor of his estate, ascertained that Edison spent more to defend his patents in court than he accrued from licenses.

Thus began the decline "fortunes" of the independent inventor in America -- the great aid in winning the American Revolution and in developing the country.