§ 419. Display of flags in assembly rooms. It shall be the duty of the school authority of every public school in the several cities and school districts of the state to purchase a sufficient number of United States flags and the necessary holders and appliances therefor for display in each assembly room of such school. The commissioner of education shall prescribe the size and material of such flags and the manner and place of their display. It shall be the duty of the teacher or other person in charge of each such assembly room to cause the flag assigned for use in such room to be displayed at all times in the manner prescribed. Wilful failure to comply with the provisions of this section shall be a misdemeanor.