Any city having a population of more than five thousand (5000) inhabitants may frame a charter for its own government, consistent with and subject to the constitution and laws of this state, by causing a convention of fifteen freeholders, who shall have been for at least five years qualified electors thereof, to be elected by the qualified voters of said city at any general or special election, whose duty it shall be within four months after such election, to prepare and propose a charter for such city, which charter, when completed, with a prefatory synopsis, shall be signed by the officers and members of the convention, or a majority thereof, and delivered to the clerk of said city, who shall publish the same in full, with his official certification, in the official paper of said city, if there be one, and if there be no official paper, then in at least one newspaper published and in general circulation in said city, three times, and a week apart, and within not less than thirty days after such publication it shall be submitted to the qualified electors of said city at a general or special election, and if a majority of such qualified voters, voting thereon, shall ratify the same, it shall at the end of sixty days thereafter, become the charter of said city, and supersede any existing charter and all amendments thereof. A duplicate certificate shall be made, setting forth the charter proposed and its ratification (together with the vote for and against) and duly certified by the City Clerk, and authenticated by the corporate seal of said city and one copy thereof shall be filed with the Secretary of State and the other deposited among the archives of the city, and shall thereupon become and be the charter of said city, and all amendments of such charter, shall be authenticated in the same manner, and filed with the secretary of state and deposited in the archives of the city.