PRESCOTT, C.J., delivered the majority opinion of the Court.

BARNES, J., concurs in the result. Concurring opinion at page 573, infra.

Interesting and important principles of law are involved in this appeal, some of which are fundamental and novel in nature. The case has been ably briefed and argued by counsel on both sides.

Appellants, the owners of three corner properties (the Stevenses, the Hostetters, and Miss Hopkins), located within the boundaries of the City of Salisbury, challenge the validity of § 42 of the Zoning Regulations of that city, which reads as follows:

"The City of Salisbury, Maryland, Ordinance No. 789

August 3, 1959

Sec. 42. Obstruction of view at intersections.

As an aid to freer safe movement of vehicles at and near street intersections and in order to promote more adequate protection of the safety of children, pedestrians, operators of vehicles and for property, for proposed construction hereafter:

1. There shall be limitations on the height of fences, walls, gateways, ornamental structures, hedges, shrubbery and other fixtures, construction and plantings in all districts where front yards are required on corner lots.

2. Such barriers to clear unobstructed vision at corners of intersecting streets shall be limited to a height of not over three feet above the established elevation of the nearest curb, for a distance of twenty-five feet along both the front and side lot lines, measured from the point of intersection, of the said intersecting lot lines.

3. Within the isosceles triangle formed as required in item 2, by connecting the ends of the respective twenty-five foot distances, all the fixtures, construction, hedges, shrubbery and other plantings shall be limited to a height not over three feet above the elevation of the curb level at the said intersecting streets.

4. Within the said triangle, and in cases where front yards are terraced, the ground elevation of such front yards shall not exceed three feet above the established curb elevation at the said intersecting streets.

5. Within two years from passage of this ordinance all barriers, except buildings and tree trunks cleared of limbs hanging below a distance of eight feet above the established curb elevation, to clear unobstructed vision within the area specified above, shall be removed."

The Stevenses own a corner lot (fronting about 93 feet on one of the intersecting streets and some 175 feet on the other) which has a natural elevation one foot in excess of the 3 foot elevation permitted by § 42 and it is supported by a masonry retaining wall covered in part by ivy. The lot is otherwise improved by several large shrubs and trees. Miss Hopkins is the owner of a corner lot having frontage on Lehigh Avenue of about 159 feet and on Philadelphia Avenue of about 137 feet. Within the triangle mentioned in the ordinance there are ornamental posts constructed of brick and stone, and hedges, shrubbery and trees or other plantings in excess of the height of 3 feet above the established elevations of the nearest curbs. The Hostetters are the owners of a lot at an intersection with frontages of about 60 feet and 102 feet on the intersecting highways. Within the triangle mentioned in the ordinance there are shrubbery and fences in excess of a height of 3 feet above the established curb elevation.

The photographic exhibits clearly disclose the hazardous nature of the respective intersections involved, and it is not denied that the barriers mentioned in all three of the cases obstruct vision within the triangular areas mentioned. The appellee, in its bills of complaint, conceded "that some or all of the aforesaid plantings and structures on the defendants' property existed prior to August 3, 1959 * * * and * * * did not violate any law or ordinance at the time same were constructed or planted." No attempt was made in the proof to show that any of the barriers had been erected or planted after the effective date of the ordinance; hence we shall assume that all of such barriers were in place prior to such effective date.

All of the defendants below demurred to the respective bills of complaint. The court below, relying upon our decision in Grant v. City of Baltimore, 212 Md. 301, overruled the demurrers, and after a hearing, the court ordered the Stevenses to remove, at their own expense, the masonry corner posts and terrace or slope of land, together with all ivy, shrubbery, grass and other plants "within said triangular area" to a height not exceeding 3 feet above the established elevation of the nearest curb. Miss Hopkins was ordered to reduce two masonry corner posts and all shrubbery and plantings (except tree trunks clear of limbs hanging below a distance of 8 feet above the established curb elevation) within "said triangular area" to a height not exceeding 3 feet above the curb elevation, or in lieu of reducing such structures, etc., in height, by removing same from the triangular area. The Hostetters were ordered to reduce all pickets of their driveway gate to the same level as the adjoining fence pickets (being approximately 3 feet, 4 inches in height) and to remove from the triangular area all existing shrubbery and plantings exceeding a height of 3 feet above the established curb elevation (except for tree trunks clear of limbs hanging below a distance of 8 feet above the curb elevation), or in lieu of removing such shrubbery and plantings by reducing same to a height not exceeding 3 feet above the curb elevation. And the defendants, their heirs, successors and assigns were permanently enjoined "to refrain thereafter from violating the said provisions of Section 42 * * *."

The property owners appealed from the decree, and the City appealed from that portion thereof which permitted the Hostetters to retain their fence pickets at a height of 3 feet, four inches.

We stated at the outset that elementary and fundamental principles were involved in this appeal. They relate to the respective rights of individual owners and of government reasonably to regulate the use of property or to take the same under its power of eminent domain. After the close of the Revolutionary War, the ownership of property in this country has frequently been referred to as "allodial" in nature or that the property is held by "allodial tenure." In its strict sense, "allodium" means land owned absolutely, and not subject to any rent, service, or other tenurial right of an overlord; however, it has been, and is, uniformly recognized throughout this country that the ownership of property is subject to the rights of government to tax the property, to regulate reasonably its use and enjoyment under the police power of the States, and to take the same, upon payment of the value thereof, when needed for a public purpose.

All the parties recognize the above; however, the appellants insist that § 42 is an attempt to "take" their property for public use without just compensation which is proscribed by Article 23 of The Declaration of Rights, Article III, § 40 of the Maryland Constitution and Amendment V of the United States Constitution, while the appellee earnestly contends that the Section is a mere "regulation of the use of property," for which no compensation need be paid.

As § 42 is obviously a zoning ordinance and is specifically so designated, it is apparent that its validity (as that of all zoning regulations) depends upon whether or not its promulgation was a proper exercise of the State's "police power." Many text-writers and able jurists have expressed themselves upon the meaning and extent of the police power of the States. Judge Cooley has collected many of such expressions and sets them forth in Chapter XVI of his thorough and splendid work. 2 Cooley, Constitutional Limitations, Ch. XVI (8th ed.). No one seems to have attempted to formulate a comprehensive definition of the term "police power," and if it were possible to do so and were done, it would destroy the flexible nature of such power, which is essential to carry out and accomplish its purposes. There can be little doubt that the ever-growing complexities of our society will call, 25 years from now, for regulations under the State's police power not now thought of.

For present purposes, the following observations with reference to the police power will suffice. Such power is broad in scope; it is an inherent attribute and prerogative of sovereignty, and has been described as essentially "no more than the power to govern." Allied Amer. Co. v. Comm'r, 219 Md. 607. It has long been recognized in this State, as established by a long line of decisions of this Court, that the Legislature has an inherent right to prescribe, within constitutional limitations, reasonable regulations, which are necessary to protect the public health, comfort, order, safety, convenience, morals and general welfare. And this right may be delegated to the municipalities of the State. LaRoque v. County Commissioners of Prince George's County, 233 Md. 329. In the instant case, the regulation involved only attempts to regulate the use and enjoyment of private property. No attack is made upon the validity of the Zoning Enabling Act, Code (1957), Article 66B, but, as stated above, the challenge is to the validity of § 42 itself.

Many years ago, it was held by this Court that the constitutional proscriptions against the taking of private property for public use without just compensation were not intended to restrain the reasonable exercise of the police power. American Coal Co. v. Allegany Co., 128 Md. 564. See also C.B. Q. Ry. v. Drainage Comm'rs, 200 U.S. 561. On the other hand, it has been held that the State cannot, under the guise of the police power, take private property for public use without compensating the owner. Capital Transit Co. v. Bosley, 191 Md. 502. Our present controversy lies in one of the above categories. Innumerable cases and books upon the subject have been found, examined and considered. The decisions and the authors seem to be in accord in stating the principles of law involved, but a careful examination of the authorities discloses that when a "regulation" approaches the line of demarcation between it and a "taking" (and we think this is such a case), it sometimes does so by almost imperceptible gradations, so that it is difficult to determine where "regulation" ends and a "taking" is effectuated.

When confronted with a similar situation, the Supreme Court of Washington, in Ackerman v. Port of Seattle, 348 P.2d 664, 668, expressed itself ably and well as follows:

"One of the fundamental principles involved in this action is the ownership of private property and the right to the free use and enjoyment thereof. Another basic principle is the authority of the government (always subject to constitutional safeguards) to regulate the use and utilization of private property for the promotion of the public welfare. At times, as in the instant litigation, these principles are in conflict, and the courts are called upon to resolve the resulting problem in human and legal relationships. In doing so, the courts constantly emphasize the concepts of (1) `regulation' under the police power, and (2) `constitutional taking or damaging' under the eminent domain power. When restrictions upon the ownership of private property fall into the category of `proper exercise of the police power,' they, validly, may be imposed without payment of compensation. The difficulty arises in deciding whether a restriction is an exercise of the police power or an exercise of the eminent domain power. When private property rights are actually destroyed through the governmental action, then police power rules are usually applicable. * * * But, when private property rights are taken from the individual and are conferred upon the public for public use, eminent domain principles are applicable."

See also 11 McQuillin, Municipal Corporations (3 rev. ed.) § 32.27; Baltimore v. Himmelfarb, 172 Md. 628.

What is a "taking of property" for which compensation must be paid and what is a reasonable curtailment of the use and enjoyment of property for which no payment need be made depend upon the facts of each particular case. Baltimore v. Marine Works, 152 Md. 367. Of course, every "taking" involves an injury to the property owner, but every injury does not involve a "taking" in a constitutional sense. M. C.C. of Balto. v. Bregenzer, 125 Md. 78.

The appellants insist that § 42 takes from them a "sight easement" over their property for the benefit of the public, and they cite the well-known airspace-easement cases relative to the flight of airplanes, such as United States v. Causby, 328 U.S. 256, Highland Park v. United States, 161 F. Supp. 597 (Ct. Cl.), Delta Air Corporation v. Kersey, 20 S.E.2d 245 (Ga.). They also cite United States v. 29.40 Acres of Land, 131 F. Supp. 84 (D.C., N.J.) where the court held that the government's limiting the landowners' use, including the types of electronic impulses that could emanate from the property, constituted a compensable servitude, and Chappell v. United States, 34 F. 673 (D.C., Md.) where an analogous ruling was made. See also Portsmouth Harbor Land Hotel Co. v. United States, 260 U.S. 327 (right to fire projectiles over landowner's property for artillery practice a "taking"). And compare McQuillin, op. cit., § 32.26, p. 329; Garrett v. Lake Roland R.R. Co., 79 Md. 277.

The appellee counters by arguing that the ordinance calls for no physical invasion of the properties involved; hence there can be no taking thereunder in a legal sense. In the view that we take of the case, it will be unnecessary to decide this question, for we shall assume, without deciding, that there can be, under proper circumstances, a taking in a constitutional sense, even though there be no direct encroachment upon private property.

This brings us to a consideration of the terms and provisions of § 42. It is well-established law that a statute or ordinance will be construed so as to avoid a conflict with the constitution whenever that course is reasonably possible. Kirkwood v. Provident Savings Bank, 205 Md. 48; Brooklyn Apts. v. M. C.C. of Balto., 189 Md. 201; Hellmann v. Collier, 217 Md. 93. If construed as a prospective enactment, compare Higgins v. City of Baltimore, 206 Md. 89, we think that certain portions of § 42 are immune from constitutional attack.

It is an accurate statement to say that every restriction upon the use and enjoyment of property is a "taking" to the extent of such restriction; but every "taking" is not a "taking" in a constitutional sense for which compensation need be paid. Allied American Co. v. Comm'r, supra, 219 Md. 607. See also the brief of Mr. Metzenbaum in the landmark zoning case of Euclid v. Ambler Co., 272 U.S. 365, 368. This Court stated in Lipsitz v. Parr, 164 Md. 222, 234: "The court has lately had for consideration the relation of the constitutional protection of property to the police power, with the result that it is now established that reasonable regulation, which is not confiscatory, but which leaves the owner in substantial enjoyment of his property, although diminishing its value through the restriction of its use, is valid without compensation." The distinctions between a taking for which compensation must be made and a taking by regulation under the police power are largely distinctions in degree. Baltimore v. Himmelfarb, 172 Md. 628; Belt R. Co. v. Sattler, 100 Md. 306; Allied American Co. v. Comm'r, supra. See also 1 Rathkopf, The Law of Zoning Planning, § 6-5; Freund, Police Power, § 518; Bent v. Emery, 53 N.E. 910 (Mass.), opinion by Justice Holmes. But in order to be compensable, the damage resulting from the restriction must be "substantial," United States v. Cress, 243 U.S. 316, 328, United States v. Causby, supra, 328 U.S. 256, 266, and constitute "severe interferences which are tantamount to deprivations of use or enjoyment of property." Baltimore v. Himmelfarb, supra.

Applying the above principles of law to the facts of the instant case, we hold that subsections 1, 2 and 3 of § 42 (as prospective measures) are lawful and valid regulations under the police power, and no compensation need be paid for the restrictions imposed therein. The constantly increasing number of motor vehicles on our highways and the mounting and appalling number of deaths and injuries from traffic accidents show the public purpose to be served by the subsections, without more being said relative thereto. The "unobstructed vision" requirement is over segments of the properties already restricted to "front yard" uses, and the height restriction of three feet is reasonable. Considering all of the attendant circumstances and especially the comparatively small portions of the properties to which the restrictions apply, it scarcely can be seriously argued, we think, that they are "confiscatory" in nature, that the owners are not left "in substantial enjoyment of their properties," or that the damages resulting from the restrictions are "substantial" in character, constituting "severe interferences which are tantamount to deprivations of use or enjoyment of property." All corner-lot owners are treated alike, and the rather small contribution in behalf of public safety and convenience required of each such owner is offset by the benefits accruing to the general public and those received from other corner-lot owners, when the first mentioned owner (or his family) becomes a member of the traveling public.

Had we been required to consider only subsections 1, 2 and 3, we would not have set forth the law at the length we did above. Subsections 4 and 5 give us more difficulty. Subsection 4 is, we think, unreasonable, confiscatory in nature, and if enforced, would amount to a taking of private property for public use without compensation. This subsection is also not entirely free from ambiguity. It has two aspects. First, it provides, "within the said triangle (emphasis ours) * * * the ground elevation of such front yards shall not exceed three feet above the * * * curb elevation * * *." This (together with subsection 5) is a mandate to property owners at intersections to grade (and remove the excess soil), at their own expense, their properties so that the ground elevation within the triangles shall not exceed three feet regardless of how much grading is required, and even if the excess in ground elevation resulted from natural causes or from lawful and permissible man-made changes. It also provides, "* * * and in cases where front yards are terraced, the ground elevation of such front yards (emphasis again ours) shall not exceed three feet above the * * * curb elevation * * *." This seems to say in no uncertain terms that if any front yard at an intersection be terraced, the ground elevation "of such front yards" (i.e. the elevation of the entire front yard) shall not exceed three feet above the curb elevation at the intersection. It is difficult to discover any sound reason why one lot owner whose front yard is not terraced may have any elevation for his front yard he desires (except in the small triangular space), but his neighbor down the street, who happens to have a terraced yard, cannot exceed an elevation of three feet at any place in his whole yard. However, this precise question is not involved in the three cases presently before us; so we pursue it no further.

As we view the situation, it is a very different thing for government to say to a property owner that you must refrain from exercising certain ordinarily permissible rights upon a relatively insignificant segment of your property to subserve a real public need (subsections 1, 2, and 3) than to require that owner to destroy, reduce, and/or remove, at his individual expense, his own property, possibly to avert the necessity of erecting, at public expense, a stop sign or other traffic signal (subsections 4 and 5). When government does the former, it is acting in the realm of regulation; when it does the latter it is traveling in the territory of a "taking." The former is a clear illustration of what the Supreme Court of Washington meant when it said in the quotation, supra, "when private property rights are actually destroyed through the government action, then police power rules are usually applicable," while the latter illustrates the statement therein, "but, when private property rights are taken from the individual and are conferred upon the public for public use, eminent domain principles are applicable." As was stated by former Chief Judge Brune: "Zoning cannot be used as a substitute for eminent domain proceedings so as to defeat the constitutional requirement for the payment of just compensation * * *." Congressional School v. State Roads Comm., 218 Md. 236. See also Scholl v. Borough of Yeadon, 26 A.2d 135 (Pa.). Or to use the oft-quoted statement of Mister Justice Holmes in Pennsylvania Coal Co. v. Mahon, 260 U.S. 393, 416: "We are in danger of forgetting that a strong public desire to improve the public condition is not enough to warrant achieving the desire by a shorter cut than the constitutional way of paying for the change."

In enacting Section 42, the City has attempted to render the maintaining of the barriers in the small triangles non-conforming uses, and then under the theory of "amortization" of non-conforming uses require the property owners to bear the expense of either removing the barriers or reducing them to a height of not over three feet. Much has been said and written concerning "sudden death," "compulsory liquidation," and "amortization" provisions relative to non-conforming uses. Practically all of the law and all of the decisions relating to amortization may be found in Grant v. City of Baltimore, supra. Harbison v. City of Buffalo, 152 N.E.2d 42 (N.Y.), and 2 Rathkopf, op. cit., Ch. 62, but it would serve no useful purpose for us to deal elaborately with such law and decisions here, for we do not believe the present situation presents a true case of amortization.

Zoning in this country will mark its fiftieth anniversary next year according to a note in 35 Va. L. Rev. 348 (however in deciding the Euclid case in 1926, the Supreme Court said zoning had been in existence in this country for about 25 years). It received a tremendous impetus in 1926, when the Supreme Court decided the celebrated case of Euclid v. Ambler, supra, and, thereafter, hundreds of cities and other municipalities have enacted and promulgated zoning regulations. Yet, at this late date, appellee states in its brief, "no case has been found construing a zoning statute identical or closely similar to Section 42 * * *." (The Lamkin case, supra, involved a similar ordinance, but the case dealt only with a front yard fence constructed after the enactment of the regulation and in spite of warning to the property owners.) True amortization provisions almost if not universally call for a termination of non-conforming uses after the lapse of a reasonable, specified period in order that the owner may amortize his investment (the reasonableness of the period depends upon the nature of the non-conforming use, the structures thereon, and the investment therein), and such amortization provisions, made for the property owners' benefit, cannot, we think, be disguised and utilized to exact a public benefit from the owners' property, under the circumstances here involved, at the owners' expense. There are, of course, a number of cases wherein property owners have been required to remove (usually under the nuisance theory) from their land structures or walls which had fallen into such a dilapidated state as to constitute menaces and dangers to the general public using streets, sidewalks, or thoroughfares, but we have been referred to no case, and have found none, where a Court of last resort has required the removal (under a zoning ordinance), at the property owners' expense for the public safety or convenience, ordinarily innocuous improvements on his dwelling-house property or his shrubbery, which were lawful and permissible at the time they were placed thereon prior to the enactment of the removal ordinance. This statement is subject to exceptions previously noted; namely, true amortization ordinances relative to non-conforming uses and the removal of weeds, brush and vegetation, and the trimming of hedges. At this point, we note particularly the provision of subsection 5 stating that all barriers should be removed "except * * * tree trunks cleared of limbs hanging below a distance of eight feet above the * * * curb elevation." Possibly this provision would be reasonable if limited to specific types of trees (for example high ones where in the usual course of events trimming or cutting back the lower branches and leaves would not destroy their value or usefulness), but the provision applies to all tree trunks. It is not difficult to foresee the incongruous results if the provision were applied to many species of trees.

In the case at bar, the principal objects ordered to be removed or reduced are a portion of a front yard still in its natural state, together with a masonry retaining wall and masonry corner post and shrubbery and ivy, on the Stevens land; two masonry corner posts and shrubbery from the Hopkins property; and pickets of a wooden driveway gate and shrubbery from the Hostetter property. Miss Hopkins and the Hostetters were also ordered to remove all trees within the triangular areas, except tree trunks clear of limbs hanging below 8 feet above the established curb elevations. The record, including the exhibits, fails to show with certainty what types of trees were here involved or what labor and expense the property owners would entail if forced to comply with the decree. The exhibits do show, however, several pieces of the shrubbery concerned. No attempt was made to show whether the shrubbery could be "trimmed" or "cut-back" to the required height without destroying its value.

As indicated above, we think the provisions of subsections 4 and 5 are unreasonable in requiring the property owners to destroy (or reduce) their property at their own expense and are therefore invalid, and we so hold. In order that this ruling may not be misunderstood, we add that under the authorities cited in footnote 2, property owners possibly may be required under the provisions of subsections 1, 2 and 3 to keep their "hedges, shrubbery and other plantings," even though planted before their enactment, trimmed to meet the height restriction, provided such trimming will not destroy the usefulness of the object trimmed or result in substantial loss to the property owner.

The learned Chancellors below relied upon our holding in the Grant case, supra, for their ruling. That case is readily distinguishable from the one at bar. It involved a discontinuance of a commercial use in a residential zone, and the ordinance called for a real amortization of a non-conforming use. The non-conforming use was caused by the property ordered to be removed: a billboard. The heart of the holding in Grant may be shown by two short excerpts therefrom. They follow: "There would seem to be a clear basis for classifying billboards separate and apart from other signs and other advertising [it was noted in the dissent in Harbison, supra, that billboards seem to occupy a category in and to themselves]," and "The distinction between an ordinance that restricts future uses and one that requires existing uses to stop after a reasonable time, is not a difference in kind but one of degree and, in each case, constitutionality depends on overall reasonableness, on the importance of the public gain in relation to the private loss." We reaffirm our holdings in Grant, and, without laboring the question unduly, repeat what we said above. We do not believe that subsections 4 and 5, which require the owners of dwelling properties to destroy or reduce customary and ordinarily harmless improvements to such properties, at their own expense for the public benefit, can be sustained as reasonable and constitutional provisions.

Our rulings above make it unnecessary to consider appellee's cross-appeal.

The appellants' demurrers should have been sustained (Maryland Rule 345 d), but leave should have been given to the appellee to amend, so that the City, if it desired, could have alleged that some of the plantings or construction had been done after the effective date of the ordinance, and/or that some of the plantings lawfully could be required to be trimmed or cut back.

Decree reversed, and case remanded for further proceedings consistent with this opinion, appellee to pay the costs.