The evidence adduced in the Superior Court was insufficient to warrant a finding that pursuit of the occupation proposed to be instituted in the barn would constitute a "use ... clearly incidental and secondary to the use of the premises for residential... purposes,” as required by § V A 9 a of the zoning by-law. See Needham v. Winslow Nurseries, Inc., 330 Mass. 95, 101 (1953) ("An incidental... *864use under a zoning law is a use which is dependent on or pertains to the principal or main use”); Harvard v. Maxant, 360 Mass. 432, 438 (1971). Contrast Sacco v. Inspector of Bldgs, of Brockton, 3 Mass. App. Ct. 749 (1975). The judgment is reversed, and a new judgment is to be entered which annuls the decision of the board of appeals as in excess of its authority.

So ordered.