I concur in the judgment of reversal. Sound judicial policy in the construction and interpretation of statutes compels the conclusion that the Pension Act in question (Stats. 1889, p. 56) is not mandatory. It has now been on the statute books for over 50 years and has not been considered as mandatory by any of the counties or cities of this state. Those few agencies which have availed themselves of its terms have done so in a manner clearly indicating their understanding that it was merely an enabling act. The legislative bodies of the counties and cities and the other officers of those agencies are presumed to have known of the existence of the law, and to have regularly performed their official duties (Code Civ. Proc., sec. 1963(15)), yet the law has not been considered or acted upon by them as mandatory legislation, and no tax has been levied to provide a fund to meet the pension demands. There are no cases in the appellate 'courts of this state where the beneficiaries under the act have sought'to compel its enforcement as mandatory legislation. These circumstances present a situation which makes certain rules of statutory construction especially pertinent and forceful. It is said that “Long-continued contemporaneous and practical interpretation of a statute by the executive officers charged with its administration and enforcement, the courts, and the public constitutes an invaluable aid in determining the meaning of a doubtful statute. ... In addition, the use *655of contemporary and practical interpretation makes for certainty in the law and justifies reliance upon the conduct of public officials.” (Sutherland Statutory Construction, 3rd ed., sec. 5103.) And “The practice and interpretive regulations by officers, administrative agencies, departmental heads and others officially charged with the duty of administering and enforcing a statute will carry great weight in determining the operation of a statute.” (Sutherland, Statutory Construction, 3rd ed., see. 5105.) And “However, interpretations made by the public and those affected by a law, interpretations resulting from the practice of the bar, and interpretations made by administrative officials of similar legislation in other jurisdictions may have important bearing as to the meaning of a statute. . . .
“Non-action by administrative officers may be indicative of a lack of statutory power. Thus it has been said by the United States Supreme Court, ‘Authority actually granted by Congress, of course,' cannot evaporate through lack of administrative exercise. But just as established practice may shed light on the- extent of power conveyed by general statutory language, so the want of assertion of power by those who presumably would be alert to exercise it, is equally significant in determining whether such power was actually conferred.’ ” (Sutherland Statutory Construction, 3rd ed., sec. 5106.) (Citing Federal Trade Commission v. Bunte Bros., 312 U.S. 349 [61 S.Ct. 580, 85 L.Ed. 881].) Further, “Like all precedents, where contemporaneous and practical interpretation has stood unchallenged for a considerable length of time it will be regarded as of great importance in arriving at the proper construction of a statute. Thus contemporaneous interpretations of five, nine, ten, eighteen, twenty, twenty-five, fifty, fifty-six, sixty, and seventy years have been permitted to govern legislative meaning. One of the soundest reasons sustaining contemporaneous interpretations of long standing is the fact that reliance has been placed thereon by the public and those having an interest in the interpretation of the law. While the principle here is not strictly that of estoppel running against the government there is some analogy to that principle when the interpretation has been made by a government agency or officer.” (Sutherland Statutory Construction, 3rd ed., sec. 5107.)
In addition to the foregoing reasoning there are other factors indicating that the legislation is not mandatory. Three *656other statutes have been enacted since 1889, which cover comprehensively the subject of pensions for county and city employees. In 1919 a statute was passed authorizing counties to establish a pension system for their employees. (Stats. 1919, p. 782.) A county peace officers’ retirement act enabling counties to make provision for pensions was adopted in 1931. (Stats. 1931, p. 477.) Cities were authorized by an act of 1937, to adopt a pension system for their employees. (Stats. 1937, p. 609.) In view of these acts it may be that the act of 1889 is no longer in effect, or at least they establish sound basis for the contention that the Legislature did not consider said act to be a mandatory statute when it adopted the above mentioned acts which embrace substantially the same subject matter as the act of 1889.
Schauer, J., concurred.