(1)  Whenever any persons, to the number of 12 or more, are riotously assembled, it is the duty of every sheriff and justice who has notice thereof to go amongst them, or as near as he can safely come to them, and to command or cause to be commanded with a loud voice that silence be kept while the proclamation next hereinafter mentioned is made, and then openly and with a loud voice to make proclamation, or cause proclamation to be made, in these words, or to the like effect;

"Our Sovereign Lord the King charges and commands all you persons here assembled immediately to disperse yourselves and peaceably to depart to your habitations or to your lawful business, failing which you will be guilty of a crime, and will be liable to be imprisoned. God Save the King!"

(2)  The performance of such duty as aforesaid by any one of the persons above mentioned shall absolve the others of them from responsibility therefor.