Teaching Machines.

Science In 1988, American Psychologist published a thorough history of teaching machines, and as the abstract demonstrates it's another example of an early pioneer being superseded by a later character with better publicity skills:

"The development of teaching machines is traced from the patented educational devices of the 19th century through the initial teaching machines of Sidney Pressey in the 1920s to the machines invented by B. F. Skinner in the 1950s. The obscurity of Pressey's pioneering work in this field contrasted with the fame achieved by Skinner is discussed in a historical context. The final sections discuss the short-lived success and eventual failure of classroom teaching machines in the 1950s and 1960s."

If nothing else, this link's worth visiting for the opening quote.