Action Comics #248 (1959)

While flying in space, Superman comes across a satellite and decides to track it to its source. He finds that it's beaming information to an uncharted island where a dictator, named Von Kamp, is forcing sailors, that were believed to be lost at sea, into building something called Project X. Superman decides to learn what he can about the project as Clark Kent and rents a boat with the intent of getting purposely captured. He soon finds that Jimmy Olsen has also stowed away on his ship when Kent is captured by the dictator and his men. Superman not only has to work hard to protect his secret identity, but make sure the Jimmy stays out of danger, and prevent the boy from escaping before he can learn the secret of Project X. When thwarting Jimmy's escape attempt as Superman, and locked in a cell as Clark Kent, Superman uses his super-powers and smart thinking to secretly save Jimmy by putting a magnet under the firing squad that is to execute them disabling them. When he learns that Project X is a spy satellite for criminals, Clark changes into Superman, and puts a kaleidoscope, making Von Kamp believe that the device is a failure. Superman then returns to the island and smashes up Von Kamp's operations, freeing his slaves and shackling Von Kamp and his troops to a giant ball and chain. Taking leave to resume his Clark Kent identity, Jimmy "relates" the story to Clark while the wait for rescue to come.