I can't let this one go without making a comment. Ships are measured in tons (units of Mass) of water displaced by the ship. Even though a given tonnage ship displaces a specific volume of water, this is not a volume mesurement.
Refrigeration unit capacities are rated by the amount (again units of Mass) of ice created (or frozen) per unit of time. Usually, here in the USA, this unit is presently given in tons. It is not a measure of the energy or heat required. Respectfully, Aaron Harper On Mon, Jan 26, 2009 at 10:39 AM, Pierre Abbat <[email protected]> wrote: > > On Monday 26 January 2009 11:41:12 Stan Jakuba wrote: > > The megagram, Mg, is in every metrication guidebook I ever saw and it is > > "common" in engineering practice and textbooks. It is safe. Because: > There > > is a whole bunch of tons, tuns, tann, tonnes, long ones, short ones, > metric > > ones, and some mean mass, other force and some both. Most people have no > > clue that those expressions may mean something else that what they think > > they do, and therein lies the danger - mistakes, because nobody will > "ask". > > And some tons mean volume (when talking about ships) or energy (amount of > heat > removed by an air conditioner). And one kind of ton is about 30 grams (the > assay ton). > > "Mg" is also the symbol for magnesium, but they're unlikely to get > confused. > > Pierre > >
