For some reason, steam power fascinates me very much. I had a couple questions about steam power and I figured this place was the best place to ask! Would it be naive of me to believe that any engine engineered correctly can be useful? What are the advantages and disadvantages of a steam engine? I asked a few people this and a lot of them said the efficiency of a steam engine is only around 30%. This confused be because a 4 stroke internal combustion engine has around the same efficiency of about 30%. Can anyone shed some insight on this for me? Thanks!