The complaint in this matter is framed under G. L. c. 149, § 27F,1 and was submitted to the Superior Court on a statement of agreed facts, the essence of which may be summarized as follows. On June 25, 1974, the defendant entered into a contract in writing with the city of Boston, acting through its department of public works, under which the defendant agreed to furnish motorized street sweepers with their operators for the purpose of keeping the streets clean in a specified section of the city. The contract provided that the defendant should pay the operators of the sweepers at the aggregate hourly rate of $6.33, representing $6.00 by way of straight wages and $.33 in lieu of payments to health and welfare plans. The components of that rate had been requested of and prescribed by the Commissioner of Labor and Industries (Commissioner), and had been specifically included in the contract, in accordance with the procedures contemplated by the first paragraph of § 27F. It was subsequently discovered, and it *418is now agreed, that the defendant paid all the operators at rates less than $6.33 per hour.
The Commissioner secured from the Municipal Court of the City of Boston nine complaints charging the defendant with violations of § 27F. The defendant was convicted on all the complaints and appealed to the Superior Court, where the single complaint now before us was submitted on the agreed facts already summarized. A Municipal Court judge, sitting in the Superior Court under statutory authority, has reported for our determination the question whether a contract such as the one already described is subject to the provisions of § 27F.2
The parties, the amicus curiae and we are all in agreement that the critical question is whether the sweeping of public ways is “public” work within the meaning of § 27F. There is no legislative history which is of any assistance in answering that question.3 The Commonwealth’s argument in favor of the Commissioner’s administrative interpretation of the statute is unpersuasive because the record is silent as to any prior occasion on which the Commissioner may have considered circumstances similar to those of the present case.4 Contrast Gillis v. Mass. Cablevision, Inc. 369 Mass. 526, 531, 534 (1976). The defendant bases its argument in part on abstract lexical definitions of “public works.” See Webster’s Third New International Dictionary *4191836 (1971 ed.) ;5 Black’s Law Dictionary 1781 (4th ed. rev. 1968). The parties and the amicus have cited numerous cases from other jurisdictions, none of which was concerned with a statute bearing any close resemblance to § 27F. “Neither answer to [the reported] question can be shown overwhelmingly to be correct, but we think the [Commonwealth’s] position is to be preferred.” Eastman Kodak Co. v. Clerk of the Third Dist. Ct. of E. Middle-sex, 372 Mass. 232, 235 (1977).
The sweeping of public ways by motorized equipment is a function which, like street sprinkling (G. L. c. 40, § 16), is commonly performed by or under the direction of superintendents of streets and boards and departments of public works in cities and towns. See G. L. c. 41, § § 21, 66, 68 and 69. It is a function akin to several of those which the Department of Public Works of the Commonwealth (DPW) is specifically required to perform in the maintenance of State highways, and which often require the use of trucks and related equipment. See G. L. c. 81, §§13 (removal of brush) and 14 (removal of trees, tree limbs and shrubbery bordering State highways). See, generally, c. 81, § 15. It is common knowledge that all the types of work just referred to can be, and often are, performed by private contractors using their own employees and equipment rather than by the public labor force using publicly owned equipment. It appears to be common ground that the street sweeping equipment here in question fell within the ambit of G. L. c. 149, § 27F, and we have no doubt that the work called for by the contract was “public” in the sense in which that word is used in the section.
The defendant’s principal argument against the applicability of § 27F is that implicit in the words “public works” is the concept of “construction,” a factor which is noticeably absent from the present case. We think the argument overlooks the framework and the subject matter of related *420provisions found in G. L. c. 149 (“LABOR AND INDUSTRIES”) . Section 27F was inserted in the subdivision of c. 149 which is entitled “PUBLIC EMPLOYMENT” (see Gallagher v. Contributory Retirement Appeal Bd. 4 Mass. App. Ct. 1, 6, 7 [1976]), at a point almost immediately following §§26 through 27D of that chapter, as then in effect.6 Each of those sections was, and still is, concerned in one way or another with the payment of minimum wages prescribed by the Commissioner to public employees as well as the employees of private contractors who are engaged in the construction of public works. Those sections were, and still are, interlaced with copious variations of the phrases “construction of public works” (§§26, 27 and 27C), and “public works to be constructed” (§§26, 27 and 27A). The words “construction” and “constructed” were, and still are, defined to include “additions to and alterations of public works” (§ 27D) 7 Sections 26 through 27D provided, and still provide, a comprehensive statutory scheme requiring the payment of the prescribed minimum wages to practically all employees, public or private, who are engaged in the “construction” of public works. It was in the light of this explicit background (see Commissioner of Labor & Indus. v. Boston Housing Authy. 345 Mass. 406, 415 [1963] ) that the Legislature selected the unqualified words “public works” which are found in § 27F. If the intention was that the prescribed wage provisions of that section should be limited in their application to employees engaged in public works involving “construction,” the new section would have been completely unnecessary. See Insurance Rating Bd. v. Commissioner of Ins. 356 Mass. 184, 189 (1969).
*421It is arguable, of course, that if the Legislature had intended to include work such as the sweeping of public ways within the ambit of § 27F, it would have said so explicitly (see Commonwealth v. Hayes, 372 Mass. 505, 509-510 [1977]), but we see no occasion for invoking the principle that an ambiguous penal statute is to be strictly construed against the Commonwealth. See Davey Bros. Inc. v. Stop & Shop, Inc. 351 Mass. 59, 63 (1966); Opinion of the Justices, 372 Mass. 874, 876 (1977).
We answer the question reported (see note 2, supra) in the affirmative.
So ordered.