The delegates so elected shall be convened at the seat of government by proclamation of the governor within six months after their election. The facilities of the legislative chambers and legislative quarters shall be made available for the convention and the delegates. Upon convening all delegates shall take an oath or affirmation to support the Constitution of the United States and of the state of Missouri, and to discharge faithfully their duties as delegates to the convention, and shall receive for their services the sum of ten dollars per diem and mileage as provided by law for members of the general assembly. A majority of the delegates shall constitute a quorum for the transaction of business, and no constitution or amendment to this constitution shall be submitted to the electors for approval or rejection unless by the assent of a majority of all the delegates-elect, the yeas and nays being entered on the journal. The convention may appoint such officers, employees and assistants as it may deem necessary, fix their compensation, provide for the printing of its documents, journals, proceedings and a record of its debates, and appropriate money for the expenditures incurred. The sessions of the convention shall be held with open doors, and it shall determine the rules of its own proceedings, choose its own officers, and be the judge of the election, returns and qualifications of its delegates. In case of a vacancy by death, resignation or other cause, the vacancy shall be filled by the governor by the appointment of another delegate of the political party of the delegate causing the vacancy.