This is only marginally connected to the topic of this forum, but I was interested to read a piece in my newspaper about Hymen L Lipman, who in 1858 patented the combined pencil and eraser. He sold the patent to a Joseph Reckendorfer for $100,000 (about $2 million today). The Faber company started producing pencils with attached erasers in the early 1870s and Reckendorfer sued. In 1875 the US Supreme Court ruled that the patent was invalid since it was a combination of two already known things with no new use. It seems therefore that Lipman's sale of the patent was pretty good business!
Build a man a fire and he's warm for a day. Set a man on fire and he's warm for the rest of his life.
I am surprised Lipman got the patent in the first place then. Perhaps Reckendorfer should sue the government for giving Lipman the patent! (We Americans always think of ways to sue. )