He wrote: “In September, 1957, Private Stone was stationed at Fort Belvoir, Virginia.
“It was about 9am while he was working inside buildings in the Post Engineer section, when someone yelled to him and others to come outside to see the odd thing coming over head towards their area.
“Private Stone and five or six others ran out and spotted an odd, black ring, moving slowly, high above the tree tops but below the broken cloud cover.
“The ring seems solid enough, not a smoke ring and Private Stone guessed the size of the ring to be about 60ft [20m] in diameter, with the ring width about five or six feet.
source: express.co.uk