When it shall appear that any unlawful assembly, or riot or disturbance of the peace has taken place, or may be reasonably apprehended, and that the police-force ordinarily employed for preserving the peace is not sufficient for its preservation and for the protection of the inhabitants and the security of property in the place where such unlawful assembly or riot or disturbance of the peace has occurred, or is apprehended, it shall be lawful for any police- officer not below the rank of Inspector to apply to the nearest Magistrate to appoint so many of the residents of the neighbourhood as such police-officers may require to act as special police-officers for such time and within such limits as he shall deem necessary; and the Magistrate to whom such application is made shall, unless he see cause to the contrary, comply with the application.