Warp schrieb:
>   Another question:
> 
>   Is there a reason that 1 gallon is exactly 231 cubic inches? Was a gallon
> first defined in terms of cubic inches? (And why such an arbitrary number
> as 231?)
> 
>   Why no such round number with cubic feet? 1 gallon = 0.133680556 cubic feet.

231 cubic inch, actually.

"The wine gallon, which some sources relate to the volume occupied by 
eight medieval merchant pounds of wine, was at one time defined as the 
volume of a cylinder six inches deep and seven inches in diameter, i.e. 
6 * (3+1/2)2 * pi ~= 230.90706 cu in.  It had been redefined during the 
reign of Queen Anne, in 1706, as 231 in^3 exactly (3 * 7 * 11 in), which 
is the result of the earlier definition with pi approximated to 22/7."

The wine gallon is the one adopted by the U.S. as "the" gallon. Note 
that Brits and Canadians went for the "imperial gallon" instead.

(WIYF)

Post a reply to this message