The great train robbery

In the Great train robbery by Edwin S Porter from 1903 was one of the first films to use editing and or very early forms of editing like cutaways and jump cuts 

In this part of the film Porter uses a cross cut to do a smooth cut from them tying up a man in the rail tower to them on the bottom of the tower waiting for the train there going to rob. This was done to add more damenton to the movie and draw in the audience into the story.