On Wednesday 27^{th} November 2013, friend of The Aperiodical and standup mathematician Matt Parker tweeted a link to his latest YouTube video.

[youtube url=http://www.youtube.com/watch?v=r7x-RGfd0Yk]

In the video Matt apologises for some remarks on the imperial number system that he made in an earlier Number Hub video about the A4 paper scale. He then goes into some of the quirkiness of the many imperial number units used for measuring length. It is an unusual ‘apology’, although very entertaining.

This got me thinking about how I think about lengths, and I tweeted that I often think in ‘metric-imperial’ units of length, or multiples of exactly 25mm in my job as a civil and structural engineer – a metric inch, if you like. Colin Wright suggested the name ‘minch’ for these units; there are then two score *minch* to the metre.