If I remember correctly, in the old days (pre American Revolution) the fluid pint and the pound both had 16 oz, and were based on the measurement of water -- "a pint's a pound the world around." In the early 19th century, the Brits adopted a 20 oz pint as part of the Imperial system, while the Yanks retained the old 16 oz one. As a result there are five US quarts to a UK gallon (but the standard 4 to a US gallon -- I'm to tired to do the math, but it works), which gives us the fifth as a measure for certain spiritous fluids. The difference also means that a liter is about half way between a US and a UK quart...so Americans are less upset by liter containers, cause they're bigger, where the Brits feel shortchanged.

An American cup hold 8 fluid ounces, but in cooking is used as a measure of volume for virtually everything. Measuring by volume was introduced by Fannie Farmer as a way of standardizing recipes, even in kitchens with minimal equipment.

And it works...I once made brownies in Norway with no measuring equipment but a big spoon. US volumetric measurements put two tablespoons to the ounce, so I worked everything out on that basis. For the oven temp conversion, I just asked my housemates what was the temp they bunged everything in at, figuring it had to be about the same as the American 350 degrees F. They came out fine.

KateG