Writing on the Mental Floss web site, Jake Rossen bemoans the fact that in decades past, many of the great TV programs aired by the BBC were systematically destroyed or taped over with no regard for their artistic value. Among the lost gems: early episodes of the first season of "The Avengers" and early "Doctor Who" shows. Rossen examines how one woman's decades-long crusade to salvage the programing and find lost prints resulted in at least some of these treasures being located and saved for posterity's sake. Click here to read.