The Imperial volume units used in Britain are vaguely metric, and different from the US customary (i.e. Queen Anne) units. The Imperial gallon is the volume of 10 lb avoirdupois of water at s.t.p. The other similarity to French metric units is they replaced a number of different application-specific volume measures.<p>At about the same time as the Imperial unit reform Britain introduced the &quot;florin&quot; 2 shilling coin, 10 per pound, another vague attempt at decimalization.