Imperial units commonly used units for length are (li), (tseung/cheung), (tsek/chek), (tsun/chun), (fen/fan) in descending scale order. These units are now rarely used in daily life, the imperial and metric systems being preferred. The imperial equivalents are written with the same basic Chinese characters as the Chinese system. In order to distinguish between the units of the two systems, the units can be prefixed with "Ying" () for the Imperial system and "Wa" () for the Chinese system. In writing, derived characters are often used, with an additional (mouth) radical to the left of the original Chinese character, for writing imperial units.
Imperial, California first school in the valley and the first Chamber of Commerce. The City of Imperial was incorporated July 12, 1904 thus being the first city in the valley to incorporate. The city was originally thought to become the county seat, but lost out to the City of El Centro in 1907. Imperial through the years became the location for the home of the Imperial Irrigation District, the California mid-winter fair and the Imperial County airport. Also several businesses were established in the city. Imperial was devastated by earthquakes in 1916 and 1940. An earthquake in 1979 destroyed many of the