I just read it as "what are some old things made of rock that people know about, to use as a reference frame?" It's the pineapple/washing machine/stonehenge un

I just read it as "what are some old things made of rock that people know about, to use as a reference frame?" It's the pineapple/washing machine/stonehenge unit system. Not to be confused with firkin/furlong/fortnight. https://en.m.wikipedia.org/wiki/FFF_system https://en.m.wikipedia.org/wiki/FFF_system