Dutch cap n chiefly seMA Cf barrack n, haycap n 1
A structure for storing hay or other crops, consisting of a roof, typically square and rising to a point in the center, supported by corner posts along which it slides, so that it can be set at any desired height.
1832 Newburyport Herald (MA) 17 Apr [3]/1 seMA, He came to the house of Mr. Jonathan Davis, 5th inst. stated that he had lain under a Dutch cap during the night previous. 1833 Andros Old Jersey 41 ceCT, I therefore turned aside into the field, ascended a stack of rye, covered with a dutch cap, and here I remained all the day. 1845 Amer. Farmer & Spirit 1.76 cnMD, A “Dutch Cap” as it is called, or movable mow, much used in New England, is the cheapest temporary covering for hay. It is composed of four upright corner posts: bored with holes at certain distances; they have a stout wooden pin inserted, on which the plates of the roof rest, and may be lowered as the hay is removed. 1889 Boston Daily Advt. (MA) 30 Sept 2/1 seMA, Picturesque Dutch caps, covering the farmers hay stacks, loom up in all directions in the fields. 1939 LANE Map 104 seMA, In southeastern Mass. the square or oblong stack may have a roof sliding on four corner posts, which is called a Dutch cap [by 3 infs] or a hay cap [by 3 infs]. 1965 PADS 43.31 Dartmouth MA, Dutch caps—for the sliding roofs sometimes put over hay stacks in the fields—was given by one informant. 2008 Westport Hist. Soc. Westport 74 seMA, [Caption:] Lassonde’s [icehouse] was on the Westport side of North Watuppa Pond. Note the “Dutch cap” covering the hay that slowed down the melting of the ice.