Mlb (2) : A traditional unit of mass for steam, equal to 1000 (not one million) pounds. This is one of many uses of the Roman numeral M to represent a multiple of 1000; all these uses should be replaced by the metric prefix k- (kilo-)
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}