I think this is going to be a really difficult one, as the invention of a lot of these is disputed.
For the record; Thomas Crapper didn't invent the flush toilet, but he did patent a lot of improvements - including the ballcock. Over to you, Stephen...
[BTW: Wiki disagrees with Stephen as to the Chinese being the first to invent it, with the ancient Orcadians going back over 5000 years!
https://en.wikipedia.org/wiki/...flush_toilet_systems ]