《The Radio Boys Trailing a Voice; Or, Solving a Wireless Mystery》 - 免费有声读物

Radio is an ideal boy’s hobby, but it is not limited to youth. Nevertheless it offers a wonderful scope for the unquenchable enthusiasm that always accompanies the application of youthful endeavor, and it is a fact that the majority of the wonderful inventions and improvements that have been made in radio have been produced by young men. To be appended and/or amended as this project proceeds - Summary by Tom Hirsch