SEC. 10. It shall not be lawful to fire or discharge any cannon, gun, pistol, fowling piece, or firearms of any description, or explode or set off any rocket, squib, torpedo, cracker or combustible fireworks of any description, in the streets, alleys or public grounds of the city; provided, that nothing herein contained shall be construed to extend to any military parade, exercise or review, or to fireworks exhibited by order of the Board, or by any exhibition which shall be authorized by a permit from the Mayor, to exhibit the same for public amusements, or to any officer of the city acting in obedience to law or ordinance.