This petition for examination of an allegedly defective piece of machinery is stated to be under G. L. c. 153, § 9, which permits one injured through some defect in his employer’s machinery to obtain a Superior Court order for examination of the machinery. General Laws c. 152, § 68 (as amended through St. 1949, c. 427, § 8), provides that c. 153 “shall not apply to employees of an insured person or a self-insurer” under the Workmen’s Compensation Law (c. 152). The defendant was so insured. No evidence is reported. There is no report of material facts. The entry of the decree imported a finding of every fact necessary to sustain it and within the scope of the pleadings. Birnbaum v. Pamoukis, 301 Mass. 559, 561-562. See Zottu v. Electronic Heating Corp. 334 Mass. 442, 446; St. Martin v. Spinner, 347 Mass. 774. It may well be that the discovery sought could not be obtained or would be irrelevant in connection with compensation relief under c. 152. A bill for discovery, however, would be in aid of an existing or possible action at law permitted by G. L. c. 152, § 15 (as amended through St. 1965, c. 487, § 1A), against a third person such as the manufacturer of the allegedly defective machine. See Turner v. Guiliano, 350 Mass. 675, 676-678. The scope and character of the petition must be judged by its essential substance and not by its title. E. S. Parks Shellac Co. v. Jones, 265 Mass. 108, 110. Tierney v. Tierney, 332 Mass. 414, 416—417. The petition viewed as a bill for discovery, makes meager allegations. On this record we cannot say it is insufficient or that it was an abuse of discretion to grant relief. The investigation afforded by c. 152, §§ 2 and 8, is not the equivalent of discovery (with respect to a possible action against a third person). See MacPherson v. Boston Edison Co. 336 Mass. 94, 100-101, 103-105.
Final decree affirmed.