The "Beer in Australia" article on Wikipedia, includes a table listing the names for various size glasses in the different states. One peculiarity is that some South Australian glasses are one size down compared to the equivalents in other states.
For example, it lists their pint glass as three quarters of an imperial pint (which would be called a schooner in other states that use that size), and their schooner glass as half a pint (which would be called a middy in a number of other states).
So my question is how did this discrepancy occur? The Wikipedia page includes a number of references that indicate that these names have been used in SA, but doesn't indicate why.