. >> jack hitt is next on booktv. he recounts america's many amateur inventors and tankers from benjamin frankel's experiment with electricity to mark zuckerberg's social media website. induorot o tchens, basements, and garages. this is about 45 minutes. [inaudible] >> so when i hit the age we start askingourselwho i wh ih17, all my friends could claim to be, you kno descendents of robert e. lee, or charles holdsworth pinkney or something like tha i didn't hear around the family house we h manfms mo a etok my mother grew exhausted with my testing in sydney to see mary pringle, an ancient cousin and amateur genealogists, primed onotraiosity i rd afte me re t ias esd a large sheet of paper bearing a set of concentric circles. in the center, mary wrote my name. and in the immediate out a circle divided path, she wrote anexleictoo my two a. rcheroth ae y four grandparents. we filled out as far as we could in every direction. in that area where her family and mine converged, a seemingly unfounded wedge flew backwards to sc