A few seconds past as I chased after it as it flew up the ride, but then it alighted a thistle head - sure enough a Frittilary, a worn but superb Silver-washed Fritillary!!
I was carrying my little handycam & there were a few expletives during the first attempts to catch it on film, but eventually it settled & allowed me to grab a bit of footage. These butterflies were once present & common in the 1950's but were lost by the early 1960's. In interesting article by Mike Gasson can be read at Moorend Nature.
Other insects of note were Southern Hawker & one very late White Admiral.
Short video of the Silver Washed Fritillary below -