Getting too Drunk to weigh water

[Tim Regan]

Hi All,

--- "Steve" wrote:
> Your Measuring Jugs are 0.7848 oz in error. Either that or the
> Imperial Ounce line is slightly lower than the 20 fluid ounce mark.

No - the UK fluid ounce and the USA fluid ounce differ. So a UK pint 
is 20 fluid ounces (UK) and 19.2 fluid ounces (USA). This seemed 
bizarre to me yesterday, but I've since found the explanation on 
<http://www.ex.ac.uk/cimt/dictunit/notes.htm#volume>:

"In the old imperial system the gallon had its own definition, 
independent of any cubic measures. It was defined (in 1824) as "the 
space occupied by 10 pounds of pure water at 62°F". (This was just 
over 277 cubic inches.)
In the 1970's when all units were re-defined in terms of metric 
measures then it was decreed that

1 (UK) gallon = 4.54609 litres (exactly)  
 It is important to remember that the UK(imperial) gallon is NOT the 
same size as the US gallon. It is bigger by about three-quarters of 
a litre.
The US gallon was originally defined to be 231 cubic inches. This 
was in fact the Queen Anne 'wine gallon' (of 1707) which has a 
traceable history back to 1493. With metrication, the US gallon is 
now defined as

1 (US) gallon = 3.785 411 784 litres (exactly) 
As the UK and US gallons are different in size, then so also are all 
the related measures: pints, gill etc.. However, the US pint (which 
is the smaller) has only 16 fluid ounces in it, against the UK pint 
which has 20 fluid ounces. The net result is that the US and UK 
fluid ounces are very close in size, with a (usually negligible) 
error of less than 4%"

Cheers,

Dumbledad.