Nigel, I know that you've been in electronics for a long time, you've been on this forum for nearly two decades, but I didn't realise you were that old.Must admit, as a kid (long before in-line skates)
https://en.wikipedia.org/wiki/Inline_skates
Inline skates, skates designed to work like ice skates during periods of warm weather, was patented by Robert John Tyers of London in 1823,