Of chronometric dating
Uncle Oliver realized that Emmett could bring in a lot of money, so he signed a deal to have Emmett become a famous silent film star, doing crazy stunts around the country. In reality, Tannen planned on keeping Emmett in the barrel for the "realistic" look.
Then they managed to steal Arthur Mc Fly's hat from Kid Tannen and had Einstein sniff it and managed to track down Arthur Mc Fly and handed him the subpoena.
Deciding to distract his father, Emmett started an argument with him regarding Emmett's future career, providing his friend clues on how to complete the rocket drill by emphasising certain words during the argument.
After the rocket drill was completed, Emmett quickly ended the argument with his father and asked the young man when he could expect a response from the patent office.
Using a handheld portable flux capacitor, Verne arrived on dry land in the barrel when its fall approached the speed of eighty-eight miles per hour.
Oliver realized that he had put Emmett's life in danger by blindly accepting that the people in charge of the stunts cared about Emmett's well-being, so he put an end to Emmett's short film career.