1957 Black Rings

[AHBotha]

Big black rings, moving over the landscape, and over cities, were noticed world wide from 1957 onwards.
South Africa, was slowly trying to get up from the effects of the last World War, and its citizens were not worried about such weird things in the sky. It was as if it was part of the last war.
These rings were first noticed in the area of Mafikeng, which was in the Northern Cape Area. Large black perfect rings, and when it moved over the properties , and the one I was living in with my parents, a deep humming sound was heard, which tended to drown out any other sounds of the neighborhood. My parents just muttered what a strange thing !
I forgot about those years, as I was abut ten years old.
Reasontly I found photos on Google Search of these rings going back to those years.
Do a search on Black Rings and go back to 1958 onwards. You will find many of these rings up to 2010. They appear to be the outer section of UFO, but like a wheel spinning you can see through the middle section of it.
I is worth checking out as there are many sightings of it, but very few discussions.
Kind regards
Andrew