Nearer the center of urban population, where the billboard nuisance is even more aggravated, the city is now the only effective repository of the police power. The county is not at present a factor in the problem; and park boards, while they have adequate police jurisdiction in their own territory, have none outside. It is competent for the city council, in the exercise of the police power, to regulate the construction of advertising signs for the protection of public decency or public safety by reasonable ordinances, but not to prohibit them altogether, nor restrict their size, construction, or location more than is reasonably necessary to keep them within the limit of safety; nor could land abutting upon parks and boulevards be subjected to substantially different regulations in this respect from those imposed upon property fronting on business streets. In the case of _Chicago_ v. _Gunning System_, already adverted to, a provision forbidding the erection of billboards on residence streets without the consent of residents in the block was condemned by the court as “an arbitrary restriction on the part of the city, depriving an individual property owner of the use of his property as he may choose, without any showing that such use would be injurious to others in the same vicinity.” The city council cannot condemn as a nuisance what the law adjudges not to be a nuisance. In order, therefore, to control offensive advertising by such regulations as the city ought to have power to impose, resort must be had to some other function of government than the police power.