Book excerpt: Baird, a British television pioneer, experimented with video recording on gramophone discs in the late 1920s. McLean (a consultant) has restored the surviving "Phonovision" discs and, using computer techniques reminiscent of an archaeological dig, has revealed the images on the discs and uncovered details of how the recordings were made. McLean also restored amateur recordings of the BBC's 30-line Television Services (1932-1935), providing a glimpse at what viewers were then watching. This book helps explain this period in television history. Illustrated with historic photographs, it sheds light on the achievements of Baird, the development of video recording, and the definition and invention of television itself. c. Book News Inc.