Mar 142015
 

If you ask someone from the US what measurement system they use, they will probably come up with a phrase something like the US Customary Units  which was "standardised" at a time just before the British Imperial system was overhauled. Which for most of the 20th century lead to the ridiculous situation where a gallon wasn't necessarily a gallon in international trade (the old pre-Imperial system had three different gallons depending on what liquid you were measuring!). And a pound wasn't necessarily a pound, and a foot wasn't necessarily a foot.

The numbers have disappeared into the background, but there were six different weights for a pound at various times.

Aaah! And this is just two systems evolved from the same origin. If every country in the world resorted to it's traditional measurement system, the world would be in chaos.

With the exception of the USA, Mynamar, and Liberia, the world has reluctantly agreed on using the metric system to avoid the cost and confusion of dealing with multiple different systems of measurement. 

Except that is not quite true. If you look at the formal definition of the US system, you will see that it is defined in terms of the metric system, and has been since 1893. Which is rather amusing – assuming that you aren't an American. If you are, it must be galling to realise that when you stubborning stick to your traditional measurement system, the rest of the world sees you rather pathetically clinging on to something that is little more than a thin veneer over what the rest of the world uses.