of the State of California it is provided, art. XII, sec. 11, that any county, city, town or township may make and enforce within its limits all such local, police, sanitary or other regulations as are not in conflict with the general laws. In these provisions may be found a grant of power to the city of Los Angeles to control the location and erection of gasworks within the city limits. In the grant of such control the fact is recognized that while the erection and maintenance of such works is a lawful business pursuit and one essential to the welfare and comfort of the community, its prosecution requires the use of materials of such a character, and such construction and maintenance of the works as not to be dangerous or offensive when carried on within thickly populated parts of the city, and such rights are consequently justly subject to regulation in such manner as to protect the public health and safety. The Supreme Court of California, as may be gathered from its opinion in this case, based its decision upon the proposition that as the exercise of the right to control the location and construction of gasworks is within the power conferred by the legislature upon the city, the act of the municipality in question cannot be reviewed, because so to do would be a substitution of the judgment of the court for that of the council upon a matter left within the exclusive control of the legislative body. To support this conclusion a citation is made from the opinion of this court in the case of Munn v. Illinois, 94 U. S. 113, to the effect that the legislature is the exclusive judge of the propriety of police regulation when the matter is within the scope of its power. The observations of Mr. Chief Justice Waite in that connection had reference to the facts of the particular case and were certainly not intended to declare the right of either the legislature or a city council to arbitrarily deprive the citizen of rights protected by the Constitution under the guise of exercising the police powers reserved to the States. It may be admitted that every inten ment is to be made in favor of the lawfulness of the exercise of municipal power, making regulations to promote the public health and

safety, and that it is not the province of courts, except in clear cases, to interfere with the exercise of the power reposed by law in municipal corporations for the protection of local rights and the health and welfare of the people in the community. But notwithstanding this general rule of the law, it is now thoroughly well settled by decisions of this court that municipal by-laws and ordinances, and even legislative enactments undertaking to regulate useful business enterprises, are subject to investigation in the courts with a view to determining whether the law or ordinance is a lawful exercise of the police power, or whether under the guise of enforcing police regulations there has been an unwarranted and arbitrary interference with the constitutional rights to carry on a lawful business, to make contracts, or to use and enjoy property. In Lawton v. Steele, 152 U. S. 133, 137, Mr. Justice Brown, speaking for the court, said upon this subject:

"To justify the State in thus interposing its authority in behalf of the public, it must appear, first, that the interests of the public generally, as distinguished from those of a particular class, require such interference; and, second, that the means are reasonably necessary for the accomplishment of the purpose, and not unduly oppressive upon individuals. The legislature may not, under the guise of protecting the public interests, arbitrarily interfere with private business or impose unusual and unnecessary restrictions upon lawful occupations. In other words, its determination as to what is a proper exercise of its police powers is not final or conclusive, but is subject to the supervision of the courts."

And, again, in Holden v. Hardy, 169 U. S. 366, 398, the same justice, again speaking for the court, said:

"The question in each case is whether the legislature has adopted the statute in exercise of a reasonable discretion, or whether its action be a mere excuse for an unjust discrimination, or the oppression or spoliation of a particular class."

And in Connolly v. Union Sewer Pipe Co., 184 U. S. 540, 558, Mr. Justice Harlan, delivering the opinion of the court, said:

"The question of constitutional law to which we have referred [the equal protection of the laws] cannot be disposed of by saying that the statute in question may be referred to what are called the police powers of the State, which, as often stated by this court, were not included in the grants of power to the General Government, and therefore reserved to the States when the Constitution was ordained. But as the Constitution of the United States is the supreme law of the land, anything in the Constitution or statutes of the States to the contrary notwithstanding, a statute of a State, even when avowedly enacted in the exercise of its police powers, must yield to that law. No right granted or secured by the Constitution of the United States can be impaired or destroyed by a state enactment, whatever may be the source from which the power to pass such enactment may have been derived. 'The nullity of any act inconsistent with the Constitution is produced by the declaration that the Constitution is the supreme law.' The State has undoubtedly the power, by appropriate legislation, to protect the public morals, the public health and the public safety, but if, by their necessary operation, its regulations looking to either of those ends amount to a denial to persons within its jurisdiction of the equal protection of the laws, they must be deemed unconstitutional and void. Gibbons v. Ogden, 9 Wheat. 1, 210; Sinnot v. Davenport, 22 How. 227, 243; Missouri, Kansas & Texas Ry. v. Haber, 169 U. S. 613, 626."

This principle was recognized and applied in the Supreme Court of California in a case decided later than the one under consideration. In re Smith, decided May 31, 1904, 77 Pac. Rep. 180, in which it was held that a county ordinance making it a misdemeanor to maintain a gasworks within a sparsely settled district was unreasonable and void. In that case the court, after again quoting from Munn v. Illinois, to the effect that the courts will not interfere with laws which are within the scope of legislative power, well said:

"But, running current with this principle, and to be read with it, is one of equal importance, namely, that when the

police power is exerted to regulate a useful business or occupation, the legislature is not the exclusive judge as to what is a reasonable and just restraint upon the constitutional right of the citizen to pursue any trade, business or vocation, which in itself is recognized as innocent and useful to the community. It is always a judicial question if any particular regulation of such right is a valid exercise of police power, though the power of the courts to declare such regulation invalid will be exercised with the utmost caution, and only where it is clear that the ordinance or law declared void passes the limits of the police powers, and infringes upon rights guaranteed by the constitution."

Applying the principles settled by these decisions to the allegations of the bill, admitted by the demurrer, we think a case is made which called for the protection of the courts against arbitrary interference with the rights of the plaintiff in error. Complying with the terms of the ordinance which was in force when the plaintiff in error was about to begin the erection of the gasworks in controversy, à tract of land was purchased within the district wherein the erection of such works was permitted, a contract was entered into for the construction of the works, a considerable sum of money was expended. It may be admitted as being a correct statement of the law as held by the California Supreme Court that, notwithstanding the grant of the permit, and even after the erection of the works, the city might still, for the protection of the public health and safety, prohibit the further maintenance and continuance of such works, and the prosecution of the business, originally harmless, may become, by reason of the manner of its prosecution or a changed condition of the community, a menace to the public health and safety. In other words, the right to exercise the police power is a continuing one, and a business lawful to-day may in the future, because of the changed situation, the growth of population or other causes, become a menace to the public health and welfare, and be required to yield to the public good. Fertilizing Co. v. Hyde

Park, 97 U. S. 659; New Orleans Gas Co. v. Louisiana Light Co., 115 U. S. 650, 672. But the exercise of the police power is subject to judicial review and property rights cannot be wrongfully destroyed by arbitrary enactment. It was averred that the works would be so constructed so as not to interfere with the health or safety of the people. No reasonable explanation for the arbitrary exercise of power in the case is suggested. The narrowing of the limits within which the plaintiff in error, in compliance with the ordinance of the city and the permit of the board of fire commissioners, was proceeding to erect the gasworks, to the smaller and more limited section, was not demanded by the public welfare, and, taking the facts as alleged in the bill, seems rather to have been actuated by a purpose to exclude the plaintiff in error from further prosecution of the enterprise. The limits of the privileged district were fixed late in August. In September the complainant began the construction of the works. In November, without changed conditions or adequate reason, the council by an amended ordinance drew a line embracing a part of the district including the complainant's property, and declared that, too, shall be prohibited territory. This action is strongly corroborative of the allegations of the bill that the purpose was not police regulation in the interest of the public but the destruction of the plaintiff's rights and the building up of another company still within the privileged district after the passage of the amendment. Being the owner of the land and having partially erected the works the plaintiff in error had acquired property rights and was entitled to protection against unconstitutional encroachments which would have the effect to deprive her of her property without due process of law. It is averred in the bill of complaint that the district within which the works were being erected was one given over to manufacturing enterprises, some of which were fully as obnoxious as gasworks possibly could be; that it contained large spaces of unoccupied lands, worthless except for manufacturing purposes, and by clear inference that there was