The return of the Commissioners to the preliminary order to show cause, (1) admits the substantial allegations of the petition, and bases their refusal upon the provisions of the acts of Congress relating to buildings and to subdivisions of lots, and the regulations made in accordance therewith.

(2) They admit that so long as the adjacent lots remain unimproved, the proposed houses "may be safe and healthy for the inmates thereof," but aver that in their judgment, when the adjacent lots are improved, the buildings proposed by relator" may become unhealthy and the public health and safety thereby become endangered."

And they further say that "while they admit that the health of the inmates will be substantially provided for, so far as said houses themselves are concerned, and so long as the adjacent land remains unimproved, they say that, in their opinion, when the adjacent property is improved, as they aver it is likely to be, the relator's houses, in combination with such adjacent improvements, are likely to produce a situation injurious to the public health and safety."

They also admit "that the exact depth of fifty feet for each lot is not essential under all circumstances to the public health and safety, but aver that some limitation of the depth of lots upon which buildings may be erected is essential to such health and safety; and that in the exercise of their best discretion, which they are advised has been committed to them by the law, they determined that fifty feet is the smallest depth that should be permitted for such purposes."

(3) They further allege that if the buildings be permitted, it will be possible for owners of lots to form irregular combinations, facing in different directions, thus requiring undue extension of water and sewer service, etc. A sketch is attached showing a possible combination of buildings of irregular size, limiting the air and light in rear of each house to the space left by the particular owner. It is not claimed, however, that the buildings proposed by the relator will require any undue extension of water and sewer service, etc.

(4) The relator moved the grant of the peremptory writ, notwithstanding the answer to the rule, and the same was sustained and final judgment entered. [From that judgment the respondents appealed.— REPORTER.]

Mr. Andrew B. Duvall, attorney for the District of Columbia, and Mr. Clarence A. Brandenburg, assistant attorney, for the appellants:

1. The regulations in question are within the exercise of the police power; they regulate for public purposes the proper use of land in connection with buildings to be erected thereon, and the land of others upon which buildings may be erected. Prentice Police Powers, 236; Powell v. Pennsyl vania, 127 U. S. 678; Thorpe v. Rutland & B. RR., 27 Vt. 140; Com. v. Alger, 7 Cush. 84; Mayor, etc., of N. Y. v. Miln, 11 Pet. 139; Hannibal, etc., RR. Co. v. Husen, 95 U. S. 465; Lake View v. Rose Hill Cemetery Co., 70 Ill. 192; Munn v. Illinois, 94 U. S. 124; Bepley v. State, 4 Ind. 264; Goddard v. Jacksonville, 15 Ill. 588; Soon Hing v. Crowley, 113 U. S. 703; B. & P. RR. Co. v. Fifth Baptist Church, 108 U. S. 317; Mugler v. State of Kansas, 123 U. S. 623; Railroad Co. v. District of Columbia, 10 App. D.

C. 126.

2. The Commissioners had ample authority to make the regulations complained of. Act of Congress of June 14, 1878, 20 Stat. 131; Act of Congress of August 27, 1888, 25 Stat. 451; Joint Resolution of Congress of February 26, 1892, 27 Stat. 394. The building regulations have been held to have the same effect as if enacted by Congress. United States v. Cole, 18 D. C. 504; Halpine v. Barr, 21 D. C. 331. The mere authority to make "building regulations" relates not alone to the materials of which the structure is to be erected. United States ex rel. Strasburger v. Commissioners, 5 Mack. 389. It is an established principle in this country that so long as the legislature does not pass the limits fixed by the Constitution, the courts have no

authority to interfere on the ground that the legislative acts in question violate the natural principles of justice and right. Tiedeman's Lim. Police Power, Sec. 2. A"building regulation" is not void because it may be considered unreasonable. It has been repeatedly held that an act of Congress is not unconstitutional and void merely because it is unreasonable; and if that be true an ordinance promulgated by the Commissioners, which Congress declares shall have the force and effect as if enacted by Congress, should not be held void even if it be unreasonable. This test of the validity of a municipal regulation cannot be applied when the power to legislate on the subject has been expressly conferred. District of Columbia v. Waggaman, 4 Mackey, 335.

3. The regulations complained of are not arbitrary requirements; they are bona-fide efforts to conserve the public health and to protect the rights of the public. Commonwealth v. Tewksbury, 11 Metc. 55; Taylor v. State, 35 Wis. 298; Blydenburgh v. Miles, 39 Conn. 484; Watertown v. Mayo, 109 Mass. 315.

4. The regulations are not void because of uncertainty. It was claimed by appellee that, under the authority of United States v. Cole, 18 D. C. 516, the regulations respecting the subdivision of lots were void, because of the "exceptions" contained therein. But we submit that the requirements of the regulations are severable; that part relating to the appellee's lot is unobjectionable, and it is therefore enforceable. The rule is settled that in a statute which contains invalid or unconstitutional provisions, if the valid and invalid are capable of separation, only the latter are to be disregarded. Albany Co. v. Stanley, 105 U. S. 305; Keokuk P. Co. v. Keokuk, 95 U. S. 80; Pressner v. Illinois, 116 U. S. 252.

5. The writ of mandamus does not lie in such a case as this against the appellants. The duty of the Commissioners and the inspector of buildings in such a case as the one at

bar is not a mere ministerial duty; it necessarily involves the construction of statutes and the exercise of judgment. Messenger Co. v. Wright, 15 App. D. C. 468.

Mr. B. F. Leighton for the appellee:

1. The Commissioners have no power to issue building regulations except such as is derived from the act of Congress which authorized the Commissioners of the District of Columbia to make such building regulations for said District as they might deem advisable. 1st Supp. R. S. U. S., p. 352. While the language of the act is broad and general in its terms, and confers upon the Commissioners ample authority to promulgate and enforce building regulations, the act does not confer upon them any authority to promulgate a regulation which does not legitimately and properly fall within the designation of a building regulation. To regulate the construction of a building is to prescribe the mode of its construction; of what it shall be built; the character of the material, thickness and strength of the walls, the adjustment and proper connection of the sewer and water pipes, and possibly, the size and ventilation of the rooms. It has nothing to do with the subdividing of the land upon which the building is to be erected, and even the power to make such regulations is limited by the rule that a building regulation to be valid must be reasonable. This principle of reasonableness must be applied to the application of the act of Congress, and the statute interpreted by its light.

The doctrine of reasonableness as applied to a building regulation is a proper test of its validity. Milliken v. City Council, 54 Tex. 394; Borling v. West et al., 29 Wis. 315; Yates v. Milwaukee, 10 Wall. 504; Buffalo v. Webster, 10 Wend. 99 (Lawyer's Co-op. Ed.); Dunham & Daniels v. Trustees of the Village of Rochester, 5 Cow. 465; Tugman v. City of Chicago, 78 Ill. 405. That portion of section 34 of the building regulations which directs that blocks of two or more dwelling-houses shall not be erected until the land upon which they are to be erected has been subdivided, so

that each house shall have a separate lot, unless a special permit be granted in each case by the Commissioners, makes by necessary implication, the orders promulgated by the Commissioners under the act to regulate subdivisions of land within the District of Columbia, a part of the building regulations themselves, as, much as though incorporated therein. Such provision has no relation to the subject of building, is not within the meaning or purpose of the act empowering the Commissioners to make building regulations, is ultra vires, and for that reason void. It is not properly a regulation at all. The Commissioners have reserved expressly the right to grant a special permit in violation of the requirement if they see fit. It seems to imply that each case is to be considered by the Commissioners by itself, and a permit granted or withheld, at their pleasure. The statute gives them no such power. United States v. Cole, 18 D. C. 516.

2. The value of property consists in the uses to which it can be put. Take away all uses to which property may be devoted, and you destroy the value of the property as effectually as though the property itself was made non-existent. The highest use to which property can be devoted is that of the home. A dwelling-house used as a place of residence cannot be, under any circumstances, injurious to property in its vicinity, or the subject of abatement as a nuisance. A building for such a purpose may be erected next door to a saloon, a theater, a soap factory, or a limekiln, in the heart of the business portion of the city or town, and no question could be raised as to the legality of such structure because of the use to which it was to be put. Such places might readily become injurious to the home, and hence, in the interests of the home, ordinances are found in many cities restraining, except under certain conditions, the use of property for the purposes indicated and other kindred objects; but no municipal ordinance can be found which prohibits the erection of a building for a home, on the ground that it is injurious to the community in which it is to be erected. No such restriction of the use of property as is sought to be here imposed, can be found anywhere in the books. The Commissioners admit, in their return, that the houses if