The trustees so elected shall hold office until the fourth Saturday in January next succeeding their election and until their successors are elected and qualify. On the third Saturday in the January next succeeding their original election, an election shall be held at which three trustees shall be chosen, one for one year, one for two years, and one for three years, and each shall qualify and enter upon the duties of the office on the fourth Saturday of the same January. On the third Saturday in each succeeding January, an election shall be held to choose a successor to the trustee whose term is about to expire, and the term of the trustee’s office shall be for three years and until a successor has qualified.