In 1834, Parliament burned down, and the Standards of Measurement were melted or destroyed. So when there's no agreed-upon standard for length: how do you fix it? Also: how you can still publicly check the length of your sandwich.

Filmed safely: https://www.tomscott.com/safe/

There's a correction to this video: the fraction on screen at 00:49 should be 1/299792458. Looks like I copied and pasted an extra 1 and didn't realise it. Apologies. You can see all the corrections for this channel at https://www.tomscott.com/corrections/

Story research by Jess Jewell

SOURCES:
Report of the Commissioners Appointed to Consider the Steps to Be Taken for Restoration of the Standards of Weight and Measure, 1841, https://books.google.co.uk/books?id=4xVSAAAAcAAJ

A Collection of the General Public Statutes, 1855, https://books.google.co.uk/books?id=UDCaqwCgBKcC

I'm at https://tomscott.com
on Twitter at https://twitter.com/tomscott
on Facebook at https://facebook.com/tomscott
and on Instagram as tomscottgo