Gilligan's Island - Season 1 - Eps 19: Gilligan Meets Jungle Boy
Gilligan discovers a jungle boy living on the island. He shows them a hole in the ground that causes objects to float, and the professor theorizes that it is expelling either helium or hydrogen. He immediately sets to work building a large balloon, with the hopes of carrying one of them back to civilization.
About Gilligan's Island

Title: Gilligan's Island
First Air Date: 1964-09-26
Last Air Date: 1967-04-17
Status: Ended
Rating: 7.431/10 (from 238 votes)
Language: EN
Seasons: 4
Total Episodes: 98
Network: CBS
Genres: Comedy, Family
Production Companies: United Artists Television, CBS, Gladysya Productions
Synopsis
The slapstick adventures of hapless Gilligan, long-suffering Skipper and their gang of mismatched castaways, all stranded on an uncharted desert isle after their tiny ship hit stormy weather.
Cast

Bob Denver
Gilligan

Alan Hale Jr.
Jonas "The Skipper" Grumby

Jim Backus
Thurston Howell, III

Natalie Schafer
Eunice "Lovey" Wentworth Howell

Tina Louise
Ginger Grant

Dawn Wells
Mary Ann Summers

Russell Johnson
Roy "The Professor" Hinkley