The string thing
I see a possible commercial opportunity here for a bloke like me on the breadline.
if I cut a number of lengths of string (non-stretchy of course) and mark each of them up for appropriate speeds and map scales, would you blokes buy them from me? I could attach a bunch of different scaled strings to a single handle for convenience. Then the blokes in the sandpits could also use it as a fly swat. I am being serious. Honest.