When you asked how people didn't figure out this device I remember a question nobody around me has been able to satisfactorily explain "Why did it take people so long to invent the steam engine?" <br><br><br>The <i>Idea</i> of using steam goes back to medieval torture designs but it took literally a thousand years to put a fan on top of that steam and harness the rotational energy that it produces. You even had the circular drums prisoners were forced to walk on to generate movement so the idea that something spinning can provide energy wasn't unheard off but it would take until around 1813 (According to wikipedia) that the steam ship was invented.<br><br><br>When ships were the most important part of any kingdom with trade and military might surely people would have been looking for ways to advance ships the same way people are looking to advance encryption or hardware in modern times.