It is provided by R. L. c. 19, § 9, that “ heads of principal departments of the Commonwealth or of a city ” (among others) shall be exempt from the civil service rules.
The reason for the exemption is plain: The selection of the heads of those departments of the Commonwealth or of a city which correspond to the cabinet officers of the President of the United States, stands on a different footing from that of subordinates and clerks. See in this connection Attorney General v. Trehy, 178 Mass. 186; Attorney General v. Douglass, 195 Mass. 35.
It is not the head of every department of a city who is within this exemption. The exemption is confined to the “heads of principal departments.” There are some twenty-six departments created by the ordinances of the city here in question. They are not all of them “principal departments.”
In our opinion the “ sealer of weights and measures department ” is not one of the “ principal departments ” of this city. The duty to be performed by that department is a ministerial one, namely, to determine the accuracy of scales and measures. See Moneyweight Scale Co. v. McBride, 199 Mass. 503, 514. The persons who make up this department are three in number. In no sense is it a “ principal ” department of this city.
The entry must be
Judgment of ouster.