Australia's constitution is contained in the Commonwealth of Australia Constitution Act 1900. In the years before this act was passed New Zealand had the opportunity to join Australia as a federal state, but decided not to. It is still possible for New Zealand to join. This 1899 cartoon shows New Zealand Premier Richard Seddon in a lifeboat leaving a ship symbolising Australia, watched by the premiers of the six Australian colonies. The caption 'Aut caesar aut nullus' (either caesar or nothing) refers to the Roman emperors and suggests that Seddon wants to be in the top position rather than a subordinate one.