OK, Whitworth, not Wentworth.
It was another 'standard' as applied to tools, fasteners and similar. A 1960's English thing I believe but am not sure, might have started earlier. What I do know was that it introduced another complete definition of tools and bolt, screw and nut 'sizes' and it made absolutely no sense in that the wrenches were huge compared with their stated value.
OFFTOPIC: if you want to see something truly impressive regarding 'standards', look up machine taper standards. There are literally dozens and dozens of them and they are all unique and none are interchangeable. No reason or rhyme at all, whatsoever. There are a handful of general guidelines (such as lathe tailstocks are <usually> Morse tapers) but no rules. It is beyond a mess. Another one is wire and gauge sizes..... there are again dozens and dozens of 'standards' in that arena also. Truly, the very best thing about standards is that there are so many of them.
Brian
Ahhh, no. I remember the Whitworth ..that was the wrench...er spanner I through in the mix. See the "W"?