When the office of governor shall become vacant, by death or otherwise, the lieutenant-governor shall possess the powers and discharge the duties of said office. When the governor shall be absent from the state or unable from protracted illness to perform the duties of the office, the lieutenant-governor shall discharge the duties of said office until the governor be able to resume his duties. If, from disability or otherwise, the lieutenant-governor shall be incapable of performing said duties or if he be absent from the state, the president of the senate pro tempore shall act in his stead; but if there be no such president or if he be disqualified by like disability or be absent from the state, then the speaker of the house of representatives shall assume the office of governor and perform said duties. In case of the inability of the foregoing officers to discharge the duties of governor, the secretary of state shall convene the senate to elect a president pro tempore. The officer discharging the duties of governor shall receive compensation as such. Should a doubt arise as to whether a vacancy has occurred in the office of governor, or as to whether any one of the disabilities mentioned in this section exists or shall have ended, then the secretary of state shall submit the question in doubt to the judges of the supreme court, who, or a majority of whom, shall investigate and determine said question and furnish to the secretary of state an opinion in writing, which shall be final and conclusive.