The county and city shall share equally in the cost of acquiring land for constructing, equipping, and furnishing the building. The building shall not be constructed or contracted to be constructed, no land shall be acquired, and no bonds shall be issued or sold by the county until the city has been authorized to issue bonds to pay its share of the cost and the ordinances providing for the bond issue have been ratified by the vote of the electors of the city in the manner provided in the city charter or by law.