Hebdo-
Hebdo- (symbol H) is an obsolete decimal metric prefix equal to 107. It is derived from the Greek hebdοmos (Greek: ἕβδομος) meaning seventh.
The definition of one hebdomometre or hebdometre as 10000000 metre was originally proposed by Rudolf Clausius for use in an absolute electrodynamic system of units named the quadrant–eleventh-gram–second system (QES system), also known as the hebdometre–undecimogramme–second system (HUS system) in the 1880s. It was based on the meridional definition of the metre which established 1/10000000 of a quadrant, a quarter of an astronomical meridian or the distance from the north pole to the equator, as a metre.
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