Surfactant prevents this collapse by reducing the surface tension of the fluids that line the lungs and helping to equalize the pressures between large and small air spaces. Surface tension is a measure of the attraction molecules of a fluid have for each other.
Buffalo Bill Cody, who later became famous for his Wild West Show, was a rider for the Pony Express and wrote of his experiences. We join Bill's story as he is hired - at the age of 15 - to ride a section of the trail that lies in modern-day Wyoming:
Ponyboy Curtis is a 14-year-old boy whose world has been turned upside down. His parents were killed in an automobile accident just eight months before The Outsiders story takes place. He lives with his oldest brother, Darry, who is 20 years old and has legal custody of him and his other brother, Sodapop, who is 16.