Any persons who shall, by any boisterous or other conduct, disturb or annoy any public or private school in this state or any person not a student who after being notified to keep off the school grounds during the school hours by the board of directors, the superintendent, or principal teacher in charge of any such school shall continue to trespass on or go upon the grounds, whether at recess or during the sessions of the school, shall be guilty of a violation and upon conviction shall be fined in any sum not exceeding one hundred dollars ($100), payable into the general school fund of the county.