Imperial and US customary measurement systems (42 US gallons, 34.97 imperial gallons or 159.0 litres) used in the oil industry has the dimension of volume and could be replaced by the gallon, cubic metre or litre. The definitions of potential difference (volt), electric current (ampere), electrical resistance (ohm) were defined in terms of metric units, international agreement having been reached at a series of IEC Congress in Chicago between 1881 and 1906 when the electrical industry was in its infancy. At that time the metric system had become established in continental Europe while in the United Kingdom metrication was an active issue. Similarly, the units of
The Civil Wars: A Tree Is Best Measured When It Is Down and a principal writer was Lebanese poet Etel Adnan, though the collage-like libretto incorporated a diverse collection of texts. Bryars set a speech by Marie Curie, "I am among those who believe that science has a great beauty", a poem by Pope Leo XIII on the then-new art of photography, and a speech by an imaginary scientist in Jules Verne's "20,000 Leagues Under the Sea". The work was not completed or publicly performed, but Bryars incorporated a number of its arias into the later works "Effarene" and "On Photography". The Civil Wars: A Tree Is Best Measured When It Is