In April 1925, on a London-Paris flight by Imperial Airways, The Lost World (1925) became the first in-flight movie to be shown to airline passengers. Safety film was developed in 1922 and was likely used in this flight which was a wood and fabric-hulled plane, converted WWI bomber, the Handley-Page 0 400.
For The Lost World (1925), Willis H. O'Brien made 49 model dinosaurs. These miniatures were donated to the Museum of Arts and Sciences in Los Angeles. After many years the rubber models began to sulphurize and disintegrate. They were stored away and inadvertently sealed between the walls of the facility when a new wing was added.
While filming one of the stop-motion scenes, the cameraman spotted a pair of pliers in the picture. So as not to draw attention to them by having them suddenly disappear, he moved them a little at a time until they were out of the shot.
The first full-length feature film to utilize stop-motion animation in the creation of its creatures.