Sec. 15. Whoever shall fire or discharge any cannon, gun, pistol revolver or any firearm of any description, or shall fire, or explode or set off any squib, firecracker, torpedo or other thing containing powder or other explosive material, without permission from the Mayor or common council so to do, within the city limits, shall, on conviction, be punished by a fine of not less than five nor more than twenty dollars; provided that such permission, when given, shall definitely limit the time of such firing, and may at any time be revoked. But nothing in this section shall prevent the ordinary and usual fireworks demonstration on National holidays; subject, however, to such regulation, control and orders as the City Marshal may deem proper to make for the protection of property from fire.