Wow, such awesome detail! It really shows how elementary Joseph Swan's invention is (yes, it is often claimed that he preceded Thomas Edison - but as a true Englishman, I'm sure you knew that).
@stray_shooter Thank you so much for your interesting comment and observation Ron, yes Thomas Edison patented many things not necessarily invented by him or his team of Engineers, he has a lot to anwer for especially how he waged a personal war with brilliant men like Nikola Tesla:)