Barometer | 21 January 2016
Roll out the barrel The price of crude oil dropped below $30 a barrel. Why do we measure it in barrels? — A standard barrel for the purposes of measuring oil is 42 US gallons or 35 imperial gallons. This was the size of a ‘tierce’, a unit for measuring wine in medieval England. — When demand for kerosene provoked an oil rush in Pennsylvania in 1859, producers were so desperate for vessels that they used all kinds of containers. — In August 1866, however, producers met in the town of Titusville to agree on a standard measure. A 42-gallon barrel of oil weighed 300lb: just enough, it was found,