This is pretty interesting-- the rings of Uranus were supposedly discovered in the 1970s, but there is some indication that William Herschel -- a brilliant observational astronomer in the 18th century who discovered Uranus in the first place -- may have observed them 200 years before!
Herschel wrote a paper in 1797 where he describes something very much like a ring around Uranus, but his findings have been dismissed because the rings are so faint that no one could believe he saw them. However, Dr. Stuart Eves of Surrey Satellite Technology Limited has re-evaluated Herschel's claims. He says Herschel got many things right-- the size, color, and orientation of the ring in the paper match what Uranus's epsilon ring would have been like back then. Very interestingly, we know that Saturn's rings are dynamic, changing on short timescales. It's possible (though I have no idea how likely) that over 200 years that Uranus's rings too have gotten fainter making them harder to detect now than in the 1790s.
I personally have no idea if this idea holds water or not, but it's certainly cool to go over old papers by those brilliant, accomplished, and extremely well-seasoned observational astronomers of yore and see how what they did then compares to what we can do now. It's best not to dismiss such old observations out of hand... but you also need to keep a jaundiced eye open. Not every observations turns out to be correct, but there may be a few cosmic needles in our celestial haystack still waiting for us to uncover.