JACK ARMSTRONG,THE ALL-AMERICAN BOY (1947) -- colorized

Jack Armstrong (1947) is a Columbia film serial, based on the radio adventure series Jack Armstrong, the All-American Boy.
Plot

Vic Hardy, a scientist working for Jim Fairfield's aviation company, is kidnapped by Jason Grood's gang after discovering radiation emitting from their secret island base. Grood intends to conquer the world and forces Hardy to assist him.

Fairfield, along with his niece and nephew and, most importantly, the hero of the title, attempt to rescue Hardy and stop Grood's plans. They are assisted by the native tribe living on the island, led by Princess Alura.
Cast

John Hart as Jack Armstrong
Rosemary LaPlanche as Betty Fairfield
Claire James as Princess Alura [Chs. 3-6,9-11, 15]
Joe Brown, Jr. as Billy Fairfield (as Joe Brown)
Pierre Watkin as Uncle Jim Fairfield
Wheeler Oakman as Prof. Hobart Zorn
Jack Ingram as Henchman Blair
Eddie Parker as Henchman Slade
Hugh Prosser as Vic Hardy

Chapter titles

Mystery of the Cosmic Ray
The Far World
Island of Deception
Into the Chasm
The Space Ship
Tunnels of Treachery
Cavern of Chance
The Secret Room
Human Targets
Battle of the Warriors
Cosmic Annihilator
The Grotto of Greed
Wheels of Fate
Journey into Space
Retribution