The most difficult mea­sure­ment units riddles

One yard is 0,91 m; one foot is 0,3 m; ell was typically 60-70 cm.

The barrel is one of several units of volume applied in various contexts; there are dry barrels, fluid barrels, oil barrels and so on. The volumes in common usage range from about 100 to 200 litres. In the worldwide oil industry, an oil barrel is defined as 42 US gallons, which is about 159 litres or 35 imperial gallons.

Nautical mile equals 1852 meters (in some countries slightly different values are used), land mile (statute mile) in the U.S. is 1609 meters, verst was approx 1077 meters.