after the Senate first meets and after each first meeting of the Senate following a dissolution thereof, the Senate shall divide the senators chosen for each State into two classes, as nearly equal in number as practicable and the places of the senators of the first class shall become vacant at the expiration of the third year three years, and the places of those of the second class at the expiration of the sixth year six years, from the beginning of their term of service and afterwards the places of senators shall be vacant at the expiration of six years from the beginning of their term of service. The election to fill vacant places shall be made in the year at the expiration of which within one year before the places are to become vacant. For the purpose of this section the term of service of a senator shall be taken to begin on the first day of January July following the day of his election, except in the cases of the first election and of the election next after any dissolution of the Senate, when it shall be taken to begin on the first day of January July preceding the day of his election. See also Referendums in Australia Politics of Australia History of Australia References Further reading . Australian Electoral Commission (2007) Referendum Dates and Results 1906 – Present AEC, Canberra. ! colspan="3" style="border-top: 5px solid #cccccc" | Amendments to the Constitution of Australia |- | style="width: 30%; text-align: center;" | Commonwealth of AustraliaConstitution Act (1900) | style="width: 30%; text-align: center;" | 2nd amendment1st State Debts amendment (1910) 1906 referendums Amendments to the Constitution of Australia 1907 in law 1906 elections in Australia Constitutional referendums in Australia December 1906 events