Special Function Sets & HPs

[ttw]

The conversions from various systems matters if one does any work with historical literature. Even metric measures change, calories are passé in thermodynamics (as are Amagats).

It's also important for surveying. Lots of property lines were established (in the US) when the yard was 3600/3937 meter as opposed to the present 36000/39372 meter. The various types of varas are amusing too, 33 inches, 33 and 1/3 inches, etc.