[USMA:26928] rhetoric and definition of the gallon

[Matthew Zotter]

2003 SEP 09 TUE   I would like to enhance my metric rhetoric by fully understanding the three gallons.� I understand that 1 gallon (UK) = 4.546 * 10^-3 m^3 (the volume of 10 lbm of water at 62 �F).� I understand that 1 gallon (US,liq) = 3.785 * 10^-3 m^3 (231 in^3, rounding off a 7 inch diameter by 6 inch height cylinder).� I do not understand why 1 gallon (US,dry) = 4.404 * 10^-3 m^3.� Does any one know where this gallon (US,dry) came from?� Also, is it true that the UK only has one type of gallon?� Thank you for your time and knowledge.   Sincerely, Matthew Zotter SC, USA