Note 258 — XXXVII THE DUTIES, ACTIVITIES, AND AMUSEMENTS OF THE ROYAL GUARDSMEN
Laurence Marcellus Larson translation
Probably some sort of a cage placed at the top or near the top of the mast from which men with bows and slings could fight to better advantage. See Aarböger for nordisk Oldkyndighed, 1872, 242; Falk, Altnordische Waffenkunde, 197.