If a protest or exceptions to the survey and plat are filed in the Secretary of State's office within the 30 days, it shall be the duty of the Secretary of State to give, through the mail, ten days' written notice of the time when he will hear the protest or exceptions at his office to the county governing authorities of the respective counties. Upon the hearing, the Secretary of State shall determine from the law and evidence the true boundary line in dispute between the respective counties.