Going back to when I was a scout, many moons ago, an outward bounds instructor told us to measure out distance in how many football fields it seems to be, and that is units of about a hundred yards. (Slightly more at Hillsborough, slightly less at Elland Rd)

Down the pit, as an apprentice working in the surface fitting shop, an electrician rang from underground to ask me to make up a Dexion rail assembly for holding a conveyer control station. He told me to make it three pick handles long, and two paper bags high......

There again, most of our nut and bolt fastenings were Whitworth... None of that Napoleon nonsense!