While I enjoyed rewatching the latter half of episode 2 of season 1 of James Burke's Connections tv series, I don't see how the invention of the cloud chamber (

While I enjoyed rewatching the latter half of episode 2 of season 1 of James Burke's Connections tv series, I don't see how the invention of the cloud chamber (which you start the video at) is relevant to standards for rail, horses, or rockets. What's the connection ?