Opinion by
Mr. Justice Chidsey,This is an appeal from the decision of the court below reversing an order of the Zoning Board of Adjustment. The appeal was taken by the Board itself and we permitted the City of Philadelphia to be substituted as appellant.1
Plaintiff is an outdoor advertising company which leased the roof area above a drugstore located in an area zoned “A” Commercial in the City of Philadelphia. Plaintiff filed an application with the Zoning Division of the Department of Licenses and Inspections for a permit to erect on the leased premises a large illuminated billboard fifteen feet high and forty-two feet wide for general advertising purposes. The Zoning Division denied the application and, on appeal, after a hearing on the merits, the Zoning Board of Adjustment refused plaintiff’s request. The Board found as *554facts that the area in which the sign was to be built was partly residential and partly commercial, that the proposed use was not an accessory use, that proper and orderly development of the neighborhood could best be obtained by limiting the area to accessory signs advertising business conducted on the premises, that the sign would be a distraction to motorists, and that the health, morals, safety and general welfare of the immediate neighborhood would be affected if permission were granted to erect the sign for general advertising, not accessory to any business at this location. Thereupon the plaintiff took its case to the Court of Common Pleas No. 1 of the County of Philadelphia which, without taking additional testimony, reversed the action of the Zoning Board and directed that a permit be issued.2 The court held that plaintiff’s billboard was permissible as an “accessory use” which is defined in Section 2(23) of the Philadelphia Zoning Ordinance as “a use subordinate to the main use on the lot and customarily incidental to the main use”. The court reasoned that the use of the roof of a business building for the erection of a sign thereon is “customarily inci*555dental” to its main nse as a business building, and that this does not turn on tbe kind of business conducted in tbe building. This appeal was then taken.3
Section 5 (3) of the Philadelphia Zoning Ordinance, which is a section of general application, provides that: “In each district, only such uses and uses accessory and incidental thereto, as are hereinafter specified, will be permitted.”. Section 16 of the Ordinance sets forth the uses allowed in an “A” Commercial District. Billboards are not among these enumerated uses. The only signs expressly permitted by Section 16 are small professional signs, bulletin boards for churches, and signs advertising the sale or rent of real estate on which they are located provided such signs do not exceed twenty-five square feet in area. Section 16 (27) of the Ordinance permits “Accessory uses customarily incidental to any of the above permitted uses.”. In Silver v. Zoning Board of Adjustment, 381 Pa. 41, 112 A. 2d 84, we held that the failure of the Philadelphia Zoning Ordinance to enumerate signs among the permitted uses in an “A” Commercial District does not allow such use, and that the only signs permitted in *556such a zoned district are those specifically enumerated by Section 16 of the Ordinance and those which could properly be classified as an accessory use.
Plaintiff maintains that its sign constitutes such an accessory use. The City, on the other hand, contends that an accessory use sign must advertise activities conducted on the premises where the sign is located, that since this sign which plaintiff proposes to erect on the space which it leased above the drugstore will be devoted to general advertising purposes, it is a non-accessory sign and therefore not permitted under the Philadelphia Zoning Ordinance. We agree with the City’s contention. In Silver v. Zoning Board of Adjustment, supra, an operator of a paint store leased a vacant lot and erected thereon a large billboard, advertising his paint business and directing prospective customers to its location which was one block away. No aspect of the advertised business was conducted on the premises where the sign was placed. This Court held that the sign was not an accessory use. We said at p. 43: “There is no question that a zoning regulation is valid if it is necessary for the preservation of public health, safety, morals or general welfare: Medinger Appeal, 377 Pa. 217, 221, 104 A. 2d 118. The regulation of billboards is generally accepted as a legitimate exercise of the police power by a zoning board: Liggett’s Petition, 291 Pa. 109, 139 A. 619; McQuillin, Municipal Corporations (3rd Ed.), Vol. 7, see. 24.380. . . .”. It is true that in the Silver case the sign in question was the only use made of the vacant lot and therefore it was a primary rather than an accessory use. However, if a billboard advertising a local business cannot be considered an accessory use if it is located on a lot one block away from the business, then it would seem that a billboard devoted to general advertising *557without reference to the businesses situated in the immediate community should not be so considered. Moreover, we think it clear that the leasing of a roof of a drugstore to an outdoor advertising company for the purpose of erecting a billboard thereon for advertising in general, is not “customarily incidental to the main use” to which the premises are being devoted. General outdoor advertising involves the conduct of a business separate and distinct in itself: Liggett's Petition, 291 Pa. 109, 139 A. 619. Plaintiff’s contemplated use of the roof bears no relationship whatever to the occupancy of the building on the subject premises. Since the use is not one customarily incidental to the operation of a drugstore, it is not an accessory use and therefore it is forbidden by the Ordinance.
Plaintiff also contends that since the erection of a similar sign by the owner of the drugstore to advertise his business conducted on the premises would be permitted as an accessory use, a refusal to permit such a sign by a lessee who seeks to make a general advertising use thereof, is a restriction which bears no substantial relation to public health, safety, morals or general welfare, and hence is unconstitutional. In 58 Am. Jur., §74, pps. 988, 989, it is said: “A zoning ordinance which excepts from a general prohibition of billboards any which refer to a business conducted on the property on which they stand is not illegally discriminative. As to this matter, it has been declared that there is no illegal discrimination in legislation limited to a particular class where there is between those in the class and those whom it leaves untouched some natural and substantial difference germane to the subject and purposes of the legislation. Neither does such an exception violate a statutory requirement that zoning regulations shall be uniform for each class or kind of buildings or structures throughout each district.”.
*558In Criterion Service, Inc. v. City of East Cleveland, 88 N.E. 2d 300, appeal dismissed, 152 Ohio St. 416, 89 N. E. 2d 475, it was held that a zoning ordinance which prohibited advertising signs and billboards except as they might be displayed as an accessory use to the business conducted on the property was constitutional, the court pointing out that outdoor advertising is a business that is subject to classification as are all other commercial enterprises. In People v. Sterling, 267 App. Div. 9, 45 N. Y. S. 2d 39, the validity of a statute prohibiting advertising signs in a public park, except where they relate to a business conducted on the premises where erected, was likewise sustained. In Murphy, Inc., et al. v. Town of Westport et al., 131 Conn. 292, 40 A. 2d 177, the court, in an extensive opinion which considered all the authorities, upheld against constitutional attack a zoning ordinance which prohibited billboards or advertising signboards in business districts except as they refer to business conducted on the property on which the billboard stands. In United Advertising Corporation v. Borough of Raritan, 11 N. J. 144, 93 A. 2d 362, the Supreme Court of New Jersey considered the validity of a zoning ordinance which prohibited any sign which directs attention to a business, commodity, service or entertainment conducted, sold or offered elsewhere than upon the premises. The Court, speaking through Mr. Justice Brennan (now of the United States Supreme Court) rejected plaintiff’s argument that the ordinance constituted unlawful discrimination by excluding advertising signs in all districts while permitting such signs directing attention to businesses on the premises, saying at pps. 365, 366: “The business sign is in actuality a part of the business itself, just as the structure housing the business is a part of it, and the authority to conduct the business in a district carries with it the right to maintain a busi*559ness sign on the premises subject to reasonable regulations in that regard as in tbe case of this ordinance. Plaintiff’s placements of its advertising signs, on tbe other band, are made pursuant to tbe conduct of tbe business of outdoor advertising itself, and in effect what tbe ordinance provides is that tbis business shall not to that extent be allowed in tbe borough. It has long been settled that tbe unique nature of outdoor advertising and tbe nuisances fostered by billboards and similar outdoor structures located by persons in tbe business of outdoor advertising, justify tbe separate classification of such structures for tbe purposes of governmental regulation and restriction. Thomas Cusack Co. v. City of Chicago, 242 U. S. 526, 37 S. Ct. 190, 61 L. Ed. 472 (1917); St. Louis Poster Adv. Co. v. City of St. Louis, 249 U. S. 269, 39 S. Ct. 274, 63 L. Ed. 599 (1919); Packer Corp. v. State of Utah, 285 U. S. 105, 52 S. Ct. 273, 76 L. Ed. 643 (1932). See also Murphy, Inc. v. Town of Westport, 131 Conn. 292, 40 A. 2d 177, 156 A.L.R. 568 (Sup. Ct. Err. 1944); General Outdoor Adv. Co., Inc. v. Department of Public Works, 289 Mass. 189, 193 N. E. 799 (Sup. Jud. Ct. 1935), appeals dismissed General Outdoor Advertising Co. v. Hoar, 296 H. S. 543, 56 S. Ct. 95, 80 L. Ed. 385 (1935) , Id., 297 U. S. 725, 56 S. Ct. 495, 80 L. Ed. 1008 (1936).”.
Plaintiff also relies on tbe case of Prospect Park Borough v. McClaskey, 151 Pa. Superior Ct. 467, 30 A. 2d 179, but in that case tbe sign was on the same tract of ground as tbe business to which it related. Tbe order of tbe court below is reversed.
See Lansdowne Borough Board of Adjustment’s Appeal, 313 Pa. 523, 170 A. 867, to the effect that the Board of Adjustment has no standing to appeal from a final order of the court of common pleas entered on an appeal from a decision of the Board. Compare Perelman et al. v. Yeadon Borough Board of Adjustment et al., 144 Pa. Superior Ct. 5, 18 A. 2d 438.
With respect to cities of the first class, Section 8 of the enabling Act of May 6, 1929, P. L. 1551, 53 PS §3829, permits persons aggrieved by the decision of the Board of Adjustment to petition the court of common pleas for a writ of certiorari. If the court allows such writ, it may then take additional testimony and may reverse or affirm, wholly or partly, or may modify the decision brought up for review. Where no additional testimony is taken in the court of common pleas, the scope of review for that court is whether the Board of Adjustment was guilty of a manifest abuse of discretion or an error of law: Devereux Foundation, Inc., Zoning Case, 351 Pa. 478, 41 A. 2d 744; Perelman et al. v. Yeadon Borough Board of Adjustment et al., 144 Pa. Superior Ct. 5, 18 A. 2d 438. See Concurring Opinion by Mr. Justice Bell in Walker v. Zoning Board of Adjustment (et al.), 380 Pa. 228, at p. 234, 110 A. 2d 414.
Since the enabling Act of May 6, 1929, P. L. 1551, 53 PS §3822 et seq., dealing with zoning ordinances of cities of the first class, does not provide for any appeal from the court below, our review is as on certiorari in its broadest sense, and we examine the record to see whether there is evidence to sustain the court’s findings and whether the proceeding is free from a violation of law and any manifest abuse of discretion. This is so whether or not testimony on the issue was taken in common pleas court. The scope of our inquiry is determined by the breadth of the certiorari issued by this Court and not by the power exercised by the court below: Food Corporation v. Zoning Board of Adjustment (et at.), 384 Pa. 288, 293, 121 A. 2d 94; Schmidt v. Philadelphia Zoning Board of Adjustment, 382 Pa. 521, 525, 114 A. 2d 902; Walker v. Zoning Board of Adjustment (et at.), 380 Pa. 228, 230, 110 A. 2d 414; Rolling Green Golf Club Case, 374 Pa. 450, 458, 97 A. 2d 523.