title_body: How did South Australia come to have smaller measures of beer?
upvoted_answer: In short, it's because of taxation. 
  
  In the Commonwealth of Australia's Parliamentary Debates of 1904 (p.8534),  The Honourable Chris Watson (who went on to become the 3rd Prime Minister) made a statement about the brewers of Sydney strongly objecting to a proposal for an excise duty on beer. The sentiment amongst Sydney's brewers was that the additional cost would be difficult to pass on to the consumer, and in fact they had thus far failed to do so. In response The Honourable Alexander Poynton, said that the tax had successfully been passed from brewers to consumers in South Australia by making the glasses smaller.
  
  For the record, The Honourable Chris Watson expressed sadness at the notion of smaller glasses.